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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/ceph/ceph_debug.h>
   3
   4#include <linux/fs.h>
   5#include <linux/wait.h>
   6#include <linux/slab.h>
   7#include <linux/gfp.h>
   8#include <linux/sched.h>
   9#include <linux/debugfs.h>
  10#include <linux/seq_file.h>
 
  11#include <linux/ratelimit.h>
  12
  13#include "super.h"
  14#include "mds_client.h"
  15
  16#include <linux/ceph/ceph_features.h>
  17#include <linux/ceph/messenger.h>
  18#include <linux/ceph/decode.h>
  19#include <linux/ceph/pagelist.h>
  20#include <linux/ceph/auth.h>
  21#include <linux/ceph/debugfs.h>
  22
  23#define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  24
  25/*
  26 * A cluster of MDS (metadata server) daemons is responsible for
  27 * managing the file system namespace (the directory hierarchy and
  28 * inodes) and for coordinating shared access to storage.  Metadata is
  29 * partitioning hierarchically across a number of servers, and that
  30 * partition varies over time as the cluster adjusts the distribution
  31 * in order to balance load.
  32 *
  33 * The MDS client is primarily responsible to managing synchronous
  34 * metadata requests for operations like open, unlink, and so forth.
  35 * If there is a MDS failure, we find out about it when we (possibly
  36 * request and) receive a new MDS map, and can resubmit affected
  37 * requests.
  38 *
  39 * For the most part, though, we take advantage of a lossless
  40 * communications channel to the MDS, and do not need to worry about
  41 * timing out or resubmitting requests.
  42 *
  43 * We maintain a stateful "session" with each MDS we interact with.
  44 * Within each session, we sent periodic heartbeat messages to ensure
  45 * any capabilities or leases we have been issues remain valid.  If
  46 * the session times out and goes stale, our leases and capabilities
  47 * are no longer valid.
  48 */
  49
  50struct ceph_reconnect_state {
  51	struct ceph_mds_session *session;
  52	int nr_caps, nr_realms;
  53	struct ceph_pagelist *pagelist;
  54	unsigned msg_version;
  55	bool allow_multi;
  56};
  57
  58static void __wake_requests(struct ceph_mds_client *mdsc,
  59			    struct list_head *head);
  60static void ceph_cap_release_work(struct work_struct *work);
  61static void ceph_cap_reclaim_work(struct work_struct *work);
  62
  63static const struct ceph_connection_operations mds_con_ops;
  64
  65
  66/*
  67 * mds reply parsing
  68 */
  69
  70static int parse_reply_info_quota(void **p, void *end,
  71				  struct ceph_mds_reply_info_in *info)
  72{
  73	u8 struct_v, struct_compat;
  74	u32 struct_len;
  75
  76	ceph_decode_8_safe(p, end, struct_v, bad);
  77	ceph_decode_8_safe(p, end, struct_compat, bad);
  78	/* struct_v is expected to be >= 1. we only
  79	 * understand encoding with struct_compat == 1. */
  80	if (!struct_v || struct_compat != 1)
  81		goto bad;
  82	ceph_decode_32_safe(p, end, struct_len, bad);
  83	ceph_decode_need(p, end, struct_len, bad);
  84	end = *p + struct_len;
  85	ceph_decode_64_safe(p, end, info->max_bytes, bad);
  86	ceph_decode_64_safe(p, end, info->max_files, bad);
  87	*p = end;
  88	return 0;
  89bad:
  90	return -EIO;
  91}
  92
  93/*
  94 * parse individual inode info
  95 */
  96static int parse_reply_info_in(void **p, void *end,
  97			       struct ceph_mds_reply_info_in *info,
  98			       u64 features)
  99{
 100	int err = 0;
 101	u8 struct_v = 0;
 102
 103	if (features == (u64)-1) {
 104		u32 struct_len;
 105		u8 struct_compat;
 106		ceph_decode_8_safe(p, end, struct_v, bad);
 107		ceph_decode_8_safe(p, end, struct_compat, bad);
 108		/* struct_v is expected to be >= 1. we only understand
 109		 * encoding with struct_compat == 1. */
 110		if (!struct_v || struct_compat != 1)
 111			goto bad;
 112		ceph_decode_32_safe(p, end, struct_len, bad);
 113		ceph_decode_need(p, end, struct_len, bad);
 114		end = *p + struct_len;
 115	}
 116
 117	ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 118	info->in = *p;
 119	*p += sizeof(struct ceph_mds_reply_inode) +
 120		sizeof(*info->in->fragtree.splits) *
 121		le32_to_cpu(info->in->fragtree.nsplits);
 122
 123	ceph_decode_32_safe(p, end, info->symlink_len, bad);
 124	ceph_decode_need(p, end, info->symlink_len, bad);
 125	info->symlink = *p;
 126	*p += info->symlink_len;
 127
 128	ceph_decode_copy_safe(p, end, &info->dir_layout,
 129			      sizeof(info->dir_layout), bad);
 
 
 
 
 130	ceph_decode_32_safe(p, end, info->xattr_len, bad);
 131	ceph_decode_need(p, end, info->xattr_len, bad);
 132	info->xattr_data = *p;
 133	*p += info->xattr_len;
 134
 135	if (features == (u64)-1) {
 136		/* inline data */
 137		ceph_decode_64_safe(p, end, info->inline_version, bad);
 138		ceph_decode_32_safe(p, end, info->inline_len, bad);
 139		ceph_decode_need(p, end, info->inline_len, bad);
 140		info->inline_data = *p;
 141		*p += info->inline_len;
 142		/* quota */
 143		err = parse_reply_info_quota(p, end, info);
 144		if (err < 0)
 145			goto out_bad;
 146		/* pool namespace */
 
 147		ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 148		if (info->pool_ns_len > 0) {
 149			ceph_decode_need(p, end, info->pool_ns_len, bad);
 150			info->pool_ns_data = *p;
 151			*p += info->pool_ns_len;
 152		}
 153
 154		/* btime */
 155		ceph_decode_need(p, end, sizeof(info->btime), bad);
 156		ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 157
 158		/* change attribute */
 159		ceph_decode_64_safe(p, end, info->change_attr, bad);
 160
 161		/* dir pin */
 162		if (struct_v >= 2) {
 163			ceph_decode_32_safe(p, end, info->dir_pin, bad);
 164		} else {
 165			info->dir_pin = -ENODATA;
 166		}
 167
 168		/* snapshot birth time, remains zero for v<=2 */
 169		if (struct_v >= 3) {
 170			ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 171			ceph_decode_copy(p, &info->snap_btime,
 172					 sizeof(info->snap_btime));
 173		} else {
 174			memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 175		}
 176
 177		*p = end;
 178	} else {
 179		if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 180			ceph_decode_64_safe(p, end, info->inline_version, bad);
 181			ceph_decode_32_safe(p, end, info->inline_len, bad);
 182			ceph_decode_need(p, end, info->inline_len, bad);
 183			info->inline_data = *p;
 184			*p += info->inline_len;
 185		} else
 186			info->inline_version = CEPH_INLINE_NONE;
 187
 188		if (features & CEPH_FEATURE_MDS_QUOTA) {
 189			err = parse_reply_info_quota(p, end, info);
 190			if (err < 0)
 191				goto out_bad;
 192		} else {
 193			info->max_bytes = 0;
 194			info->max_files = 0;
 195		}
 196
 197		info->pool_ns_len = 0;
 198		info->pool_ns_data = NULL;
 199		if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 200			ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 201			if (info->pool_ns_len > 0) {
 202				ceph_decode_need(p, end, info->pool_ns_len, bad);
 203				info->pool_ns_data = *p;
 204				*p += info->pool_ns_len;
 205			}
 206		}
 207
 208		if (features & CEPH_FEATURE_FS_BTIME) {
 209			ceph_decode_need(p, end, sizeof(info->btime), bad);
 210			ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 211			ceph_decode_64_safe(p, end, info->change_attr, bad);
 212		}
 213
 214		info->dir_pin = -ENODATA;
 215		/* info->snap_btime remains zero */
 216	}
 217	return 0;
 218bad:
 219	err = -EIO;
 220out_bad:
 221	return err;
 222}
 223
 224static int parse_reply_info_dir(void **p, void *end,
 225				struct ceph_mds_reply_dirfrag **dirfrag,
 226				u64 features)
 227{
 228	if (features == (u64)-1) {
 229		u8 struct_v, struct_compat;
 230		u32 struct_len;
 231		ceph_decode_8_safe(p, end, struct_v, bad);
 232		ceph_decode_8_safe(p, end, struct_compat, bad);
 233		/* struct_v is expected to be >= 1. we only understand
 234		 * encoding whose struct_compat == 1. */
 235		if (!struct_v || struct_compat != 1)
 236			goto bad;
 237		ceph_decode_32_safe(p, end, struct_len, bad);
 238		ceph_decode_need(p, end, struct_len, bad);
 239		end = *p + struct_len;
 240	}
 241
 242	ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 243	*dirfrag = *p;
 244	*p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 245	if (unlikely(*p > end))
 246		goto bad;
 247	if (features == (u64)-1)
 248		*p = end;
 249	return 0;
 250bad:
 251	return -EIO;
 252}
 253
 254static int parse_reply_info_lease(void **p, void *end,
 255				  struct ceph_mds_reply_lease **lease,
 256				  u64 features)
 257{
 258	if (features == (u64)-1) {
 259		u8 struct_v, struct_compat;
 260		u32 struct_len;
 261		ceph_decode_8_safe(p, end, struct_v, bad);
 262		ceph_decode_8_safe(p, end, struct_compat, bad);
 263		/* struct_v is expected to be >= 1. we only understand
 264		 * encoding whose struct_compat == 1. */
 265		if (!struct_v || struct_compat != 1)
 266			goto bad;
 267		ceph_decode_32_safe(p, end, struct_len, bad);
 268		ceph_decode_need(p, end, struct_len, bad);
 269		end = *p + struct_len;
 270	}
 271
 272	ceph_decode_need(p, end, sizeof(**lease), bad);
 273	*lease = *p;
 274	*p += sizeof(**lease);
 275	if (features == (u64)-1)
 276		*p = end;
 277	return 0;
 278bad:
 279	return -EIO;
 280}
 281
 282/*
 283 * parse a normal reply, which may contain a (dir+)dentry and/or a
 284 * target inode.
 285 */
 286static int parse_reply_info_trace(void **p, void *end,
 287				  struct ceph_mds_reply_info_parsed *info,
 288				  u64 features)
 289{
 290	int err;
 291
 292	if (info->head->is_dentry) {
 293		err = parse_reply_info_in(p, end, &info->diri, features);
 294		if (err < 0)
 295			goto out_bad;
 296
 297		err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 298		if (err < 0)
 299			goto out_bad;
 
 
 
 
 300
 301		ceph_decode_32_safe(p, end, info->dname_len, bad);
 302		ceph_decode_need(p, end, info->dname_len, bad);
 303		info->dname = *p;
 304		*p += info->dname_len;
 305
 306		err = parse_reply_info_lease(p, end, &info->dlease, features);
 307		if (err < 0)
 308			goto out_bad;
 309	}
 310
 311	if (info->head->is_target) {
 312		err = parse_reply_info_in(p, end, &info->targeti, features);
 313		if (err < 0)
 314			goto out_bad;
 315	}
 316
 317	if (unlikely(*p != end))
 318		goto bad;
 319	return 0;
 320
 321bad:
 322	err = -EIO;
 323out_bad:
 324	pr_err("problem parsing mds trace %d\n", err);
 325	return err;
 326}
 327
 328/*
 329 * parse readdir results
 330 */
 331static int parse_reply_info_readdir(void **p, void *end,
 332				struct ceph_mds_reply_info_parsed *info,
 333				u64 features)
 334{
 335	u32 num, i = 0;
 336	int err;
 337
 338	err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 339	if (err < 0)
 340		goto out_bad;
 
 
 
 
 341
 342	ceph_decode_need(p, end, sizeof(num) + 2, bad);
 343	num = ceph_decode_32(p);
 344	{
 345		u16 flags = ceph_decode_16(p);
 346		info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 347		info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 348		info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 349		info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 350	}
 351	if (num == 0)
 352		goto done;
 353
 354	BUG_ON(!info->dir_entries);
 355	if ((unsigned long)(info->dir_entries + num) >
 356	    (unsigned long)info->dir_entries + info->dir_buf_size) {
 357		pr_err("dir contents are larger than expected\n");
 358		WARN_ON(1);
 359		goto bad;
 360	}
 361
 362	info->dir_nr = num;
 363	while (num) {
 364		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 365		/* dentry */
 366		ceph_decode_32_safe(p, end, rde->name_len, bad);
 
 367		ceph_decode_need(p, end, rde->name_len, bad);
 368		rde->name = *p;
 369		*p += rde->name_len;
 370		dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 
 
 371
 372		/* dentry lease */
 373		err = parse_reply_info_lease(p, end, &rde->lease, features);
 374		if (err)
 375			goto out_bad;
 376		/* inode */
 377		err = parse_reply_info_in(p, end, &rde->inode, features);
 378		if (err < 0)
 379			goto out_bad;
 380		/* ceph_readdir_prepopulate() will update it */
 381		rde->offset = 0;
 382		i++;
 383		num--;
 384	}
 385
 386done:
 387	/* Skip over any unrecognized fields */
 388	*p = end;
 389	return 0;
 390
 391bad:
 392	err = -EIO;
 393out_bad:
 394	pr_err("problem parsing dir contents %d\n", err);
 395	return err;
 396}
 397
 398/*
 399 * parse fcntl F_GETLK results
 400 */
 401static int parse_reply_info_filelock(void **p, void *end,
 402				     struct ceph_mds_reply_info_parsed *info,
 403				     u64 features)
 404{
 405	if (*p + sizeof(*info->filelock_reply) > end)
 406		goto bad;
 407
 408	info->filelock_reply = *p;
 
 409
 410	/* Skip over any unrecognized fields */
 411	*p = end;
 412	return 0;
 
 413bad:
 414	return -EIO;
 415}
 416
 417/*
 418 * parse create results
 419 */
 420static int parse_reply_info_create(void **p, void *end,
 421				  struct ceph_mds_reply_info_parsed *info,
 422				  u64 features)
 423{
 424	if (features == (u64)-1 ||
 425	    (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 426		/* Malformed reply? */
 427		if (*p == end) {
 428			info->has_create_ino = false;
 429		} else {
 430			info->has_create_ino = true;
 431			ceph_decode_64_safe(p, end, info->ino, bad);
 432		}
 433	} else {
 434		if (*p != end)
 435			goto bad;
 436	}
 437
 438	/* Skip over any unrecognized fields */
 439	*p = end;
 440	return 0;
 
 441bad:
 442	return -EIO;
 443}
 444
 445/*
 446 * parse extra results
 447 */
 448static int parse_reply_info_extra(void **p, void *end,
 449				  struct ceph_mds_reply_info_parsed *info,
 450				  u64 features)
 451{
 452	u32 op = le32_to_cpu(info->head->op);
 453
 454	if (op == CEPH_MDS_OP_GETFILELOCK)
 455		return parse_reply_info_filelock(p, end, info, features);
 456	else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 457		return parse_reply_info_readdir(p, end, info, features);
 458	else if (op == CEPH_MDS_OP_CREATE)
 459		return parse_reply_info_create(p, end, info, features);
 460	else
 461		return -EIO;
 462}
 463
 464/*
 465 * parse entire mds reply
 466 */
 467static int parse_reply_info(struct ceph_msg *msg,
 468			    struct ceph_mds_reply_info_parsed *info,
 469			    u64 features)
 470{
 471	void *p, *end;
 472	u32 len;
 473	int err;
 474
 475	info->head = msg->front.iov_base;
 476	p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 477	end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 478
 479	/* trace */
 480	ceph_decode_32_safe(&p, end, len, bad);
 481	if (len > 0) {
 482		ceph_decode_need(&p, end, len, bad);
 483		err = parse_reply_info_trace(&p, p+len, info, features);
 484		if (err < 0)
 485			goto out_bad;
 486	}
 487
 488	/* extra */
 489	ceph_decode_32_safe(&p, end, len, bad);
 490	if (len > 0) {
 491		ceph_decode_need(&p, end, len, bad);
 492		err = parse_reply_info_extra(&p, p+len, info, features);
 493		if (err < 0)
 494			goto out_bad;
 495	}
 496
 497	/* snap blob */
 498	ceph_decode_32_safe(&p, end, len, bad);
 499	info->snapblob_len = len;
 500	info->snapblob = p;
 501	p += len;
 502
 503	if (p != end)
 504		goto bad;
 505	return 0;
 506
 507bad:
 508	err = -EIO;
 509out_bad:
 510	pr_err("mds parse_reply err %d\n", err);
 511	return err;
 512}
 513
 514static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 515{
 516	if (!info->dir_entries)
 517		return;
 518	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 519}
 520
 521
 522/*
 523 * sessions
 524 */
 525const char *ceph_session_state_name(int s)
 526{
 527	switch (s) {
 528	case CEPH_MDS_SESSION_NEW: return "new";
 529	case CEPH_MDS_SESSION_OPENING: return "opening";
 530	case CEPH_MDS_SESSION_OPEN: return "open";
 531	case CEPH_MDS_SESSION_HUNG: return "hung";
 532	case CEPH_MDS_SESSION_CLOSING: return "closing";
 533	case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 534	case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 535	case CEPH_MDS_SESSION_REJECTED: return "rejected";
 536	default: return "???";
 537	}
 538}
 539
 540static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 541{
 542	if (refcount_inc_not_zero(&s->s_ref)) {
 543		dout("mdsc get_session %p %d -> %d\n", s,
 544		     refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 545		return s;
 546	} else {
 547		dout("mdsc get_session %p 0 -- FAIL\n", s);
 548		return NULL;
 549	}
 550}
 551
 552void ceph_put_mds_session(struct ceph_mds_session *s)
 553{
 554	dout("mdsc put_session %p %d -> %d\n", s,
 555	     refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 556	if (refcount_dec_and_test(&s->s_ref)) {
 557		if (s->s_auth.authorizer)
 558			ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 559		kfree(s);
 560	}
 561}
 562
 563/*
 564 * called under mdsc->mutex
 565 */
 566struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 567						   int mds)
 568{
 569	if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 
 
 570		return NULL;
 571	return get_session(mdsc->sessions[mds]);
 
 
 
 
 572}
 573
 574static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 575{
 576	if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 577		return false;
 578	else
 579		return true;
 580}
 581
 582static int __verify_registered_session(struct ceph_mds_client *mdsc,
 583				       struct ceph_mds_session *s)
 584{
 585	if (s->s_mds >= mdsc->max_sessions ||
 586	    mdsc->sessions[s->s_mds] != s)
 587		return -ENOENT;
 588	return 0;
 589}
 590
 591/*
 592 * create+register a new session for given mds.
 593 * called under mdsc->mutex.
 594 */
 595static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 596						 int mds)
 597{
 598	struct ceph_mds_session *s;
 599
 600	if (mds >= mdsc->mdsmap->m_num_mds)
 601		return ERR_PTR(-EINVAL);
 602
 603	s = kzalloc(sizeof(*s), GFP_NOFS);
 604	if (!s)
 605		return ERR_PTR(-ENOMEM);
 606
 607	if (mds >= mdsc->max_sessions) {
 608		int newmax = 1 << get_count_order(mds + 1);
 609		struct ceph_mds_session **sa;
 610
 611		dout("%s: realloc to %d\n", __func__, newmax);
 612		sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 613		if (!sa)
 614			goto fail_realloc;
 615		if (mdsc->sessions) {
 616			memcpy(sa, mdsc->sessions,
 617			       mdsc->max_sessions * sizeof(void *));
 618			kfree(mdsc->sessions);
 619		}
 620		mdsc->sessions = sa;
 621		mdsc->max_sessions = newmax;
 622	}
 623
 624	dout("%s: mds%d\n", __func__, mds);
 625	s->s_mdsc = mdsc;
 626	s->s_mds = mds;
 627	s->s_state = CEPH_MDS_SESSION_NEW;
 628	s->s_ttl = 0;
 629	s->s_seq = 0;
 630	mutex_init(&s->s_mutex);
 631
 632	ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 633
 634	spin_lock_init(&s->s_gen_ttl_lock);
 635	s->s_cap_gen = 1;
 636	s->s_cap_ttl = jiffies - 1;
 637
 638	spin_lock_init(&s->s_cap_lock);
 639	s->s_renew_requested = 0;
 640	s->s_renew_seq = 0;
 641	INIT_LIST_HEAD(&s->s_caps);
 642	s->s_nr_caps = 0;
 643	refcount_set(&s->s_ref, 1);
 
 644	INIT_LIST_HEAD(&s->s_waiting);
 645	INIT_LIST_HEAD(&s->s_unsafe);
 646	s->s_num_cap_releases = 0;
 647	s->s_cap_reconnect = 0;
 648	s->s_cap_iterator = NULL;
 649	INIT_LIST_HEAD(&s->s_cap_releases);
 650	INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 651
 652	INIT_LIST_HEAD(&s->s_cap_flushing);
 653
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 654	mdsc->sessions[mds] = s;
 655	atomic_inc(&mdsc->num_sessions);
 656	refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 657
 658	ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 659		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 660
 661	return s;
 662
 663fail_realloc:
 664	kfree(s);
 665	return ERR_PTR(-ENOMEM);
 666}
 667
 668/*
 669 * called under mdsc->mutex
 670 */
 671static void __unregister_session(struct ceph_mds_client *mdsc,
 672			       struct ceph_mds_session *s)
 673{
 674	dout("__unregister_session mds%d %p\n", s->s_mds, s);
 675	BUG_ON(mdsc->sessions[s->s_mds] != s);
 676	mdsc->sessions[s->s_mds] = NULL;
 677	s->s_state = 0;
 678	ceph_con_close(&s->s_con);
 679	ceph_put_mds_session(s);
 680	atomic_dec(&mdsc->num_sessions);
 681}
 682
 683/*
 684 * drop session refs in request.
 685 *
 686 * should be last request ref, or hold mdsc->mutex
 687 */
 688static void put_request_session(struct ceph_mds_request *req)
 689{
 690	if (req->r_session) {
 691		ceph_put_mds_session(req->r_session);
 692		req->r_session = NULL;
 693	}
 694}
 695
 696void ceph_mdsc_release_request(struct kref *kref)
 697{
 698	struct ceph_mds_request *req = container_of(kref,
 699						    struct ceph_mds_request,
 700						    r_kref);
 701	destroy_reply_info(&req->r_reply_info);
 702	if (req->r_request)
 703		ceph_msg_put(req->r_request);
 704	if (req->r_reply)
 705		ceph_msg_put(req->r_reply);
 706	if (req->r_inode) {
 707		ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 708		/* avoid calling iput_final() in mds dispatch threads */
 709		ceph_async_iput(req->r_inode);
 710	}
 711	if (req->r_parent)
 712		ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 713	ceph_async_iput(req->r_target_inode);
 714	if (req->r_dentry)
 715		dput(req->r_dentry);
 716	if (req->r_old_dentry)
 717		dput(req->r_old_dentry);
 718	if (req->r_old_dentry_dir) {
 719		/*
 720		 * track (and drop pins for) r_old_dentry_dir
 721		 * separately, since r_old_dentry's d_parent may have
 722		 * changed between the dir mutex being dropped and
 723		 * this request being freed.
 724		 */
 725		ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 726				  CEPH_CAP_PIN);
 727		ceph_async_iput(req->r_old_dentry_dir);
 728	}
 729	kfree(req->r_path1);
 730	kfree(req->r_path2);
 731	if (req->r_pagelist)
 732		ceph_pagelist_release(req->r_pagelist);
 733	put_request_session(req);
 734	ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 735	WARN_ON_ONCE(!list_empty(&req->r_wait));
 736	kfree(req);
 737}
 738
 739DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 740
 741/*
 742 * lookup session, bump ref if found.
 743 *
 744 * called under mdsc->mutex.
 745 */
 746static struct ceph_mds_request *
 747lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 748{
 749	struct ceph_mds_request *req;
 750
 751	req = lookup_request(&mdsc->request_tree, tid);
 752	if (req)
 753		ceph_mdsc_get_request(req);
 754
 755	return req;
 756}
 757
 758/*
 759 * Register an in-flight request, and assign a tid.  Link to directory
 760 * are modifying (if any).
 761 *
 762 * Called under mdsc->mutex.
 763 */
 764static void __register_request(struct ceph_mds_client *mdsc,
 765			       struct ceph_mds_request *req,
 766			       struct inode *dir)
 767{
 768	int ret = 0;
 769
 770	req->r_tid = ++mdsc->last_tid;
 771	if (req->r_num_caps) {
 772		ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 773					req->r_num_caps);
 774		if (ret < 0) {
 775			pr_err("__register_request %p "
 776			       "failed to reserve caps: %d\n", req, ret);
 777			/* set req->r_err to fail early from __do_request */
 778			req->r_err = ret;
 779			return;
 780		}
 781	}
 782	dout("__register_request %p tid %lld\n", req, req->r_tid);
 783	ceph_mdsc_get_request(req);
 784	insert_request(&mdsc->request_tree, req);
 785
 786	req->r_uid = current_fsuid();
 787	req->r_gid = current_fsgid();
 788
 789	if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 790		mdsc->oldest_tid = req->r_tid;
 791
 792	if (dir) {
 793		ihold(dir);
 794		req->r_unsafe_dir = dir;
 795	}
 796}
 797
 798static void __unregister_request(struct ceph_mds_client *mdsc,
 799				 struct ceph_mds_request *req)
 800{
 801	dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 802
 803	/* Never leave an unregistered request on an unsafe list! */
 804	list_del_init(&req->r_unsafe_item);
 805
 806	if (req->r_tid == mdsc->oldest_tid) {
 807		struct rb_node *p = rb_next(&req->r_node);
 808		mdsc->oldest_tid = 0;
 809		while (p) {
 810			struct ceph_mds_request *next_req =
 811				rb_entry(p, struct ceph_mds_request, r_node);
 812			if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 813				mdsc->oldest_tid = next_req->r_tid;
 814				break;
 815			}
 816			p = rb_next(p);
 817		}
 818	}
 819
 820	erase_request(&mdsc->request_tree, req);
 821
 822	if (req->r_unsafe_dir  &&
 823	    test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 824		struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 825		spin_lock(&ci->i_unsafe_lock);
 826		list_del_init(&req->r_unsafe_dir_item);
 827		spin_unlock(&ci->i_unsafe_lock);
 828	}
 829	if (req->r_target_inode &&
 830	    test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 831		struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 832		spin_lock(&ci->i_unsafe_lock);
 833		list_del_init(&req->r_unsafe_target_item);
 834		spin_unlock(&ci->i_unsafe_lock);
 835	}
 836
 837	if (req->r_unsafe_dir) {
 838		/* avoid calling iput_final() in mds dispatch threads */
 839		ceph_async_iput(req->r_unsafe_dir);
 840		req->r_unsafe_dir = NULL;
 841	}
 842
 843	complete_all(&req->r_safe_completion);
 844
 845	ceph_mdsc_put_request(req);
 846}
 847
 848/*
 849 * Walk back up the dentry tree until we hit a dentry representing a
 850 * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 851 * when calling this) to ensure that the objects won't disappear while we're
 852 * working with them. Once we hit a candidate dentry, we attempt to take a
 853 * reference to it, and return that as the result.
 854 */
 855static struct inode *get_nonsnap_parent(struct dentry *dentry)
 856{
 857	struct inode *inode = NULL;
 858
 859	while (dentry && !IS_ROOT(dentry)) {
 860		inode = d_inode_rcu(dentry);
 861		if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 862			break;
 863		dentry = dentry->d_parent;
 864	}
 865	if (inode)
 866		inode = igrab(inode);
 867	return inode;
 868}
 869
 870/*
 871 * Choose mds to send request to next.  If there is a hint set in the
 872 * request (e.g., due to a prior forward hint from the mds), use that.
 873 * Otherwise, consult frag tree and/or caps to identify the
 874 * appropriate mds.  If all else fails, choose randomly.
 875 *
 876 * Called under mdsc->mutex.
 877 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 878static int __choose_mds(struct ceph_mds_client *mdsc,
 879			struct ceph_mds_request *req)
 880{
 881	struct inode *inode;
 882	struct ceph_inode_info *ci;
 883	struct ceph_cap *cap;
 884	int mode = req->r_direct_mode;
 885	int mds = -1;
 886	u32 hash = req->r_direct_hash;
 887	bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 888
 889	/*
 890	 * is there a specific mds we should try?  ignore hint if we have
 891	 * no session and the mds is not up (active or recovering).
 892	 */
 893	if (req->r_resend_mds >= 0 &&
 894	    (__have_session(mdsc, req->r_resend_mds) ||
 895	     ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 896		dout("choose_mds using resend_mds mds%d\n",
 897		     req->r_resend_mds);
 898		return req->r_resend_mds;
 899	}
 900
 901	if (mode == USE_RANDOM_MDS)
 902		goto random;
 903
 904	inode = NULL;
 905	if (req->r_inode) {
 906		if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
 907			inode = req->r_inode;
 908			ihold(inode);
 909		} else {
 910			/* req->r_dentry is non-null for LSSNAP request */
 911			rcu_read_lock();
 912			inode = get_nonsnap_parent(req->r_dentry);
 913			rcu_read_unlock();
 914			dout("__choose_mds using snapdir's parent %p\n", inode);
 915		}
 916	} else if (req->r_dentry) {
 917		/* ignore race with rename; old or new d_parent is okay */
 918		struct dentry *parent;
 919		struct inode *dir;
 920
 921		rcu_read_lock();
 922		parent = READ_ONCE(req->r_dentry->d_parent);
 923		dir = req->r_parent ? : d_inode_rcu(parent);
 924
 925		if (!dir || dir->i_sb != mdsc->fsc->sb) {
 926			/*  not this fs or parent went negative */
 927			inode = d_inode(req->r_dentry);
 928			if (inode)
 929				ihold(inode);
 930		} else if (ceph_snap(dir) != CEPH_NOSNAP) {
 931			/* direct snapped/virtual snapdir requests
 932			 * based on parent dir inode */
 933			inode = get_nonsnap_parent(parent);
 
 934			dout("__choose_mds using nonsnap parent %p\n", inode);
 935		} else {
 936			/* dentry target */
 937			inode = d_inode(req->r_dentry);
 938			if (!inode || mode == USE_AUTH_MDS) {
 939				/* dir + name */
 940				inode = igrab(dir);
 941				hash = ceph_dentry_hash(dir, req->r_dentry);
 942				is_hash = true;
 943			} else {
 944				ihold(inode);
 945			}
 946		}
 947		rcu_read_unlock();
 948	}
 949
 950	dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 951	     (int)hash, mode);
 952	if (!inode)
 953		goto random;
 954	ci = ceph_inode(inode);
 955
 956	if (is_hash && S_ISDIR(inode->i_mode)) {
 957		struct ceph_inode_frag frag;
 958		int found;
 959
 960		ceph_choose_frag(ci, hash, &frag, &found);
 961		if (found) {
 962			if (mode == USE_ANY_MDS && frag.ndist > 0) {
 963				u8 r;
 964
 965				/* choose a random replica */
 966				get_random_bytes(&r, 1);
 967				r %= frag.ndist;
 968				mds = frag.dist[r];
 969				dout("choose_mds %p %llx.%llx "
 970				     "frag %u mds%d (%d/%d)\n",
 971				     inode, ceph_vinop(inode),
 972				     frag.frag, mds,
 973				     (int)r, frag.ndist);
 974				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 975				    CEPH_MDS_STATE_ACTIVE)
 976					goto out;
 977			}
 978
 979			/* since this file/dir wasn't known to be
 980			 * replicated, then we want to look for the
 981			 * authoritative mds. */
 982			mode = USE_AUTH_MDS;
 983			if (frag.mds >= 0) {
 984				/* choose auth mds */
 985				mds = frag.mds;
 986				dout("choose_mds %p %llx.%llx "
 987				     "frag %u mds%d (auth)\n",
 988				     inode, ceph_vinop(inode), frag.frag, mds);
 989				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 990				    CEPH_MDS_STATE_ACTIVE)
 991					goto out;
 992			}
 993		}
 994	}
 995
 996	spin_lock(&ci->i_ceph_lock);
 997	cap = NULL;
 998	if (mode == USE_AUTH_MDS)
 999		cap = ci->i_auth_cap;
1000	if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1001		cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1002	if (!cap) {
1003		spin_unlock(&ci->i_ceph_lock);
1004		ceph_async_iput(inode);
1005		goto random;
1006	}
1007	mds = cap->session->s_mds;
1008	dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
1009	     inode, ceph_vinop(inode), mds,
1010	     cap == ci->i_auth_cap ? "auth " : "", cap);
1011	spin_unlock(&ci->i_ceph_lock);
1012out:
1013	/* avoid calling iput_final() while holding mdsc->mutex or
1014	 * in mds dispatch threads */
1015	ceph_async_iput(inode);
1016	return mds;
1017
1018random:
1019	mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1020	dout("choose_mds chose random mds%d\n", mds);
1021	return mds;
1022}
1023
1024
1025/*
1026 * session messages
1027 */
1028static struct ceph_msg *create_session_msg(u32 op, u64 seq)
1029{
1030	struct ceph_msg *msg;
1031	struct ceph_mds_session_head *h;
1032
1033	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1034			   false);
1035	if (!msg) {
1036		pr_err("create_session_msg ENOMEM creating msg\n");
1037		return NULL;
1038	}
1039	h = msg->front.iov_base;
1040	h->op = cpu_to_le32(op);
1041	h->seq = cpu_to_le64(seq);
1042
1043	return msg;
1044}
1045
1046static void encode_supported_features(void **p, void *end)
1047{
1048	static const unsigned char bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1049	static const size_t count = ARRAY_SIZE(bits);
1050
1051	if (count > 0) {
1052		size_t i;
1053		size_t size = ((size_t)bits[count - 1] + 64) / 64 * 8;
1054
1055		BUG_ON(*p + 4 + size > end);
1056		ceph_encode_32(p, size);
1057		memset(*p, 0, size);
1058		for (i = 0; i < count; i++)
1059			((unsigned char*)(*p))[i / 8] |= 1 << (bits[i] % 8);
1060		*p += size;
1061	} else {
1062		BUG_ON(*p + 4 > end);
1063		ceph_encode_32(p, 0);
1064	}
1065}
1066
1067/*
1068 * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1069 * to include additional client metadata fields.
1070 */
1071static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1072{
1073	struct ceph_msg *msg;
1074	struct ceph_mds_session_head *h;
1075	int i = -1;
1076	int extra_bytes = 0;
1077	int metadata_key_count = 0;
1078	struct ceph_options *opt = mdsc->fsc->client->options;
1079	struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1080	void *p, *end;
1081
1082	const char* metadata[][2] = {
1083		{"hostname", mdsc->nodename},
1084		{"kernel_version", init_utsname()->release},
1085		{"entity_id", opt->name ? : ""},
1086		{"root", fsopt->server_path ? : "/"},
1087		{NULL, NULL}
1088	};
1089
1090	/* Calculate serialized length of metadata */
1091	extra_bytes = 4;  /* map length */
1092	for (i = 0; metadata[i][0]; ++i) {
1093		extra_bytes += 8 + strlen(metadata[i][0]) +
1094			strlen(metadata[i][1]);
1095		metadata_key_count++;
1096	}
1097	/* supported feature */
1098	extra_bytes += 4 + 8;
1099
1100	/* Allocate the message */
1101	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1102			   GFP_NOFS, false);
1103	if (!msg) {
1104		pr_err("create_session_msg ENOMEM creating msg\n");
1105		return NULL;
1106	}
1107	p = msg->front.iov_base;
1108	end = p + msg->front.iov_len;
1109
1110	h = p;
1111	h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1112	h->seq = cpu_to_le64(seq);
1113
1114	/*
1115	 * Serialize client metadata into waiting buffer space, using
1116	 * the format that userspace expects for map<string, string>
1117	 *
1118	 * ClientSession messages with metadata are v2
1119	 */
1120	msg->hdr.version = cpu_to_le16(3);
1121	msg->hdr.compat_version = cpu_to_le16(1);
1122
1123	/* The write pointer, following the session_head structure */
1124	p += sizeof(*h);
1125
1126	/* Number of entries in the map */
1127	ceph_encode_32(&p, metadata_key_count);
1128
1129	/* Two length-prefixed strings for each entry in the map */
1130	for (i = 0; metadata[i][0]; ++i) {
1131		size_t const key_len = strlen(metadata[i][0]);
1132		size_t const val_len = strlen(metadata[i][1]);
1133
1134		ceph_encode_32(&p, key_len);
1135		memcpy(p, metadata[i][0], key_len);
1136		p += key_len;
1137		ceph_encode_32(&p, val_len);
1138		memcpy(p, metadata[i][1], val_len);
1139		p += val_len;
1140	}
1141
1142	encode_supported_features(&p, end);
1143	msg->front.iov_len = p - msg->front.iov_base;
1144	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1145
1146	return msg;
1147}
1148
1149/*
1150 * send session open request.
1151 *
1152 * called under mdsc->mutex
1153 */
1154static int __open_session(struct ceph_mds_client *mdsc,
1155			  struct ceph_mds_session *session)
1156{
1157	struct ceph_msg *msg;
1158	int mstate;
1159	int mds = session->s_mds;
1160
1161	/* wait for mds to go active? */
1162	mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1163	dout("open_session to mds%d (%s)\n", mds,
1164	     ceph_mds_state_name(mstate));
1165	session->s_state = CEPH_MDS_SESSION_OPENING;
1166	session->s_renew_requested = jiffies;
1167
1168	/* send connect message */
1169	msg = create_session_open_msg(mdsc, session->s_seq);
1170	if (!msg)
1171		return -ENOMEM;
1172	ceph_con_send(&session->s_con, msg);
1173	return 0;
1174}
1175
1176/*
1177 * open sessions for any export targets for the given mds
1178 *
1179 * called under mdsc->mutex
1180 */
1181static struct ceph_mds_session *
1182__open_export_target_session(struct ceph_mds_client *mdsc, int target)
1183{
1184	struct ceph_mds_session *session;
1185
1186	session = __ceph_lookup_mds_session(mdsc, target);
1187	if (!session) {
1188		session = register_session(mdsc, target);
1189		if (IS_ERR(session))
1190			return session;
1191	}
1192	if (session->s_state == CEPH_MDS_SESSION_NEW ||
1193	    session->s_state == CEPH_MDS_SESSION_CLOSING)
1194		__open_session(mdsc, session);
1195
1196	return session;
1197}
1198
1199struct ceph_mds_session *
1200ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1201{
1202	struct ceph_mds_session *session;
1203
1204	dout("open_export_target_session to mds%d\n", target);
1205
1206	mutex_lock(&mdsc->mutex);
1207	session = __open_export_target_session(mdsc, target);
1208	mutex_unlock(&mdsc->mutex);
1209
1210	return session;
1211}
1212
1213static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1214					  struct ceph_mds_session *session)
1215{
1216	struct ceph_mds_info *mi;
1217	struct ceph_mds_session *ts;
1218	int i, mds = session->s_mds;
1219
1220	if (mds >= mdsc->mdsmap->m_num_mds)
1221		return;
1222
1223	mi = &mdsc->mdsmap->m_info[mds];
1224	dout("open_export_target_sessions for mds%d (%d targets)\n",
1225	     session->s_mds, mi->num_export_targets);
1226
1227	for (i = 0; i < mi->num_export_targets; i++) {
1228		ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1229		if (!IS_ERR(ts))
1230			ceph_put_mds_session(ts);
1231	}
1232}
1233
1234void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1235					   struct ceph_mds_session *session)
1236{
1237	mutex_lock(&mdsc->mutex);
1238	__open_export_target_sessions(mdsc, session);
1239	mutex_unlock(&mdsc->mutex);
1240}
1241
1242/*
1243 * session caps
1244 */
1245
1246static void detach_cap_releases(struct ceph_mds_session *session,
1247				struct list_head *target)
 
 
1248{
1249	lockdep_assert_held(&session->s_cap_lock);
1250
1251	list_splice_init(&session->s_cap_releases, target);
1252	session->s_num_cap_releases = 0;
1253	dout("dispose_cap_releases mds%d\n", session->s_mds);
1254}
1255
1256static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1257				 struct list_head *dispose)
1258{
1259	while (!list_empty(dispose)) {
1260		struct ceph_cap *cap;
1261		/* zero out the in-progress message */
1262		cap = list_first_entry(dispose, struct ceph_cap, session_caps);
 
1263		list_del(&cap->session_caps);
1264		ceph_put_cap(mdsc, cap);
1265	}
1266}
1267
1268static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1269				     struct ceph_mds_session *session)
1270{
1271	struct ceph_mds_request *req;
1272	struct rb_node *p;
1273	struct ceph_inode_info *ci;
1274
1275	dout("cleanup_session_requests mds%d\n", session->s_mds);
1276	mutex_lock(&mdsc->mutex);
1277	while (!list_empty(&session->s_unsafe)) {
1278		req = list_first_entry(&session->s_unsafe,
1279				       struct ceph_mds_request, r_unsafe_item);
1280		pr_warn_ratelimited(" dropping unsafe request %llu\n",
1281				    req->r_tid);
1282		if (req->r_target_inode) {
1283			/* dropping unsafe change of inode's attributes */
1284			ci = ceph_inode(req->r_target_inode);
1285			errseq_set(&ci->i_meta_err, -EIO);
1286		}
1287		if (req->r_unsafe_dir) {
1288			/* dropping unsafe directory operation */
1289			ci = ceph_inode(req->r_unsafe_dir);
1290			errseq_set(&ci->i_meta_err, -EIO);
1291		}
1292		__unregister_request(mdsc, req);
1293	}
1294	/* zero r_attempts, so kick_requests() will re-send requests */
1295	p = rb_first(&mdsc->request_tree);
1296	while (p) {
1297		req = rb_entry(p, struct ceph_mds_request, r_node);
1298		p = rb_next(p);
1299		if (req->r_session &&
1300		    req->r_session->s_mds == session->s_mds)
1301			req->r_attempts = 0;
1302	}
1303	mutex_unlock(&mdsc->mutex);
1304}
1305
1306/*
1307 * Helper to safely iterate over all caps associated with a session, with
1308 * special care taken to handle a racing __ceph_remove_cap().
1309 *
1310 * Caller must hold session s_mutex.
1311 */
1312int ceph_iterate_session_caps(struct ceph_mds_session *session,
1313			      int (*cb)(struct inode *, struct ceph_cap *,
1314					void *), void *arg)
1315{
1316	struct list_head *p;
1317	struct ceph_cap *cap;
1318	struct inode *inode, *last_inode = NULL;
1319	struct ceph_cap *old_cap = NULL;
1320	int ret;
1321
1322	dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1323	spin_lock(&session->s_cap_lock);
1324	p = session->s_caps.next;
1325	while (p != &session->s_caps) {
1326		cap = list_entry(p, struct ceph_cap, session_caps);
1327		inode = igrab(&cap->ci->vfs_inode);
1328		if (!inode) {
1329			p = p->next;
1330			continue;
1331		}
1332		session->s_cap_iterator = cap;
1333		spin_unlock(&session->s_cap_lock);
1334
1335		if (last_inode) {
1336			/* avoid calling iput_final() while holding
1337			 * s_mutex or in mds dispatch threads */
1338			ceph_async_iput(last_inode);
1339			last_inode = NULL;
1340		}
1341		if (old_cap) {
1342			ceph_put_cap(session->s_mdsc, old_cap);
1343			old_cap = NULL;
1344		}
1345
1346		ret = cb(inode, cap, arg);
1347		last_inode = inode;
1348
1349		spin_lock(&session->s_cap_lock);
1350		p = p->next;
1351		if (!cap->ci) {
1352			dout("iterate_session_caps  finishing cap %p removal\n",
1353			     cap);
1354			BUG_ON(cap->session != session);
1355			cap->session = NULL;
1356			list_del_init(&cap->session_caps);
1357			session->s_nr_caps--;
1358			if (cap->queue_release)
1359				__ceph_queue_cap_release(session, cap);
1360			else
 
 
1361				old_cap = cap;  /* put_cap it w/o locks held */
 
1362		}
1363		if (ret < 0)
1364			goto out;
1365	}
1366	ret = 0;
1367out:
1368	session->s_cap_iterator = NULL;
1369	spin_unlock(&session->s_cap_lock);
1370
1371	ceph_async_iput(last_inode);
1372	if (old_cap)
1373		ceph_put_cap(session->s_mdsc, old_cap);
1374
1375	return ret;
1376}
1377
1378static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1379				  void *arg)
1380{
1381	struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1382	struct ceph_inode_info *ci = ceph_inode(inode);
1383	LIST_HEAD(to_remove);
1384	bool dirty_dropped = false;
1385	bool invalidate = false;
1386
1387	dout("removing cap %p, ci is %p, inode is %p\n",
1388	     cap, ci, &ci->vfs_inode);
1389	spin_lock(&ci->i_ceph_lock);
1390	if (cap->mds_wanted | cap->issued)
1391		ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1392	__ceph_remove_cap(cap, false);
1393	if (!ci->i_auth_cap) {
1394		struct ceph_cap_flush *cf;
1395		struct ceph_mds_client *mdsc = fsc->mdsc;
1396
1397		if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1398			if (inode->i_data.nrpages > 0)
1399				invalidate = true;
1400			if (ci->i_wrbuffer_ref > 0)
1401				mapping_set_error(&inode->i_data, -EIO);
1402		}
1403
1404		while (!list_empty(&ci->i_cap_flush_list)) {
1405			cf = list_first_entry(&ci->i_cap_flush_list,
1406					      struct ceph_cap_flush, i_list);
1407			list_move(&cf->i_list, &to_remove);
1408		}
1409
1410		spin_lock(&mdsc->cap_dirty_lock);
1411
1412		list_for_each_entry(cf, &to_remove, i_list)
1413			list_del(&cf->g_list);
1414
1415		if (!list_empty(&ci->i_dirty_item)) {
1416			pr_warn_ratelimited(
1417				" dropping dirty %s state for %p %lld\n",
1418				ceph_cap_string(ci->i_dirty_caps),
1419				inode, ceph_ino(inode));
1420			ci->i_dirty_caps = 0;
1421			list_del_init(&ci->i_dirty_item);
1422			dirty_dropped = true;
1423		}
1424		if (!list_empty(&ci->i_flushing_item)) {
1425			pr_warn_ratelimited(
1426				" dropping dirty+flushing %s state for %p %lld\n",
1427				ceph_cap_string(ci->i_flushing_caps),
1428				inode, ceph_ino(inode));
1429			ci->i_flushing_caps = 0;
1430			list_del_init(&ci->i_flushing_item);
1431			mdsc->num_cap_flushing--;
1432			dirty_dropped = true;
1433		}
1434		spin_unlock(&mdsc->cap_dirty_lock);
1435
1436		if (dirty_dropped) {
1437			errseq_set(&ci->i_meta_err, -EIO);
1438
1439			if (ci->i_wrbuffer_ref_head == 0 &&
1440			    ci->i_wr_ref == 0 &&
1441			    ci->i_dirty_caps == 0 &&
1442			    ci->i_flushing_caps == 0) {
1443				ceph_put_snap_context(ci->i_head_snapc);
1444				ci->i_head_snapc = NULL;
1445			}
1446		}
1447
1448		if (atomic_read(&ci->i_filelock_ref) > 0) {
1449			/* make further file lock syscall return -EIO */
1450			ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1451			pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1452					    inode, ceph_ino(inode));
1453		}
1454
1455		if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1456			list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1457			ci->i_prealloc_cap_flush = NULL;
1458		}
1459	}
1460	spin_unlock(&ci->i_ceph_lock);
1461	while (!list_empty(&to_remove)) {
1462		struct ceph_cap_flush *cf;
1463		cf = list_first_entry(&to_remove,
1464				      struct ceph_cap_flush, i_list);
1465		list_del(&cf->i_list);
1466		ceph_free_cap_flush(cf);
1467	}
1468
1469	wake_up_all(&ci->i_cap_wq);
1470	if (invalidate)
1471		ceph_queue_invalidate(inode);
1472	if (dirty_dropped)
1473		iput(inode);
1474	return 0;
1475}
1476
1477/*
1478 * caller must hold session s_mutex
1479 */
1480static void remove_session_caps(struct ceph_mds_session *session)
1481{
1482	struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1483	struct super_block *sb = fsc->sb;
1484	LIST_HEAD(dispose);
1485
1486	dout("remove_session_caps on %p\n", session);
1487	ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1488
1489	wake_up_all(&fsc->mdsc->cap_flushing_wq);
1490
1491	spin_lock(&session->s_cap_lock);
1492	if (session->s_nr_caps > 0) {
1493		struct inode *inode;
1494		struct ceph_cap *cap, *prev = NULL;
1495		struct ceph_vino vino;
1496		/*
1497		 * iterate_session_caps() skips inodes that are being
1498		 * deleted, we need to wait until deletions are complete.
1499		 * __wait_on_freeing_inode() is designed for the job,
1500		 * but it is not exported, so use lookup inode function
1501		 * to access it.
1502		 */
1503		while (!list_empty(&session->s_caps)) {
1504			cap = list_entry(session->s_caps.next,
1505					 struct ceph_cap, session_caps);
1506			if (cap == prev)
1507				break;
1508			prev = cap;
1509			vino = cap->ci->i_vino;
1510			spin_unlock(&session->s_cap_lock);
1511
1512			inode = ceph_find_inode(sb, vino);
1513			 /* avoid calling iput_final() while holding s_mutex */
1514			ceph_async_iput(inode);
1515
1516			spin_lock(&session->s_cap_lock);
1517		}
1518	}
1519
1520	// drop cap expires and unlock s_cap_lock
1521	detach_cap_releases(session, &dispose);
1522
1523	BUG_ON(session->s_nr_caps > 0);
1524	BUG_ON(!list_empty(&session->s_cap_flushing));
1525	spin_unlock(&session->s_cap_lock);
1526	dispose_cap_releases(session->s_mdsc, &dispose);
1527}
1528
1529enum {
1530	RECONNECT,
1531	RENEWCAPS,
1532	FORCE_RO,
1533};
1534
1535/*
1536 * wake up any threads waiting on this session's caps.  if the cap is
1537 * old (didn't get renewed on the client reconnect), remove it now.
1538 *
1539 * caller must hold s_mutex.
1540 */
1541static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1542			      void *arg)
1543{
1544	struct ceph_inode_info *ci = ceph_inode(inode);
1545	unsigned long ev = (unsigned long)arg;
1546
1547	if (ev == RECONNECT) {
1548		spin_lock(&ci->i_ceph_lock);
1549		ci->i_wanted_max_size = 0;
1550		ci->i_requested_max_size = 0;
1551		spin_unlock(&ci->i_ceph_lock);
1552	} else if (ev == RENEWCAPS) {
1553		if (cap->cap_gen < cap->session->s_cap_gen) {
1554			/* mds did not re-issue stale cap */
1555			spin_lock(&ci->i_ceph_lock);
1556			cap->issued = cap->implemented = CEPH_CAP_PIN;
1557			/* make sure mds knows what we want */
1558			if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
1559				ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1560			spin_unlock(&ci->i_ceph_lock);
1561		}
1562	} else if (ev == FORCE_RO) {
1563	}
1564	wake_up_all(&ci->i_cap_wq);
1565	return 0;
1566}
1567
1568static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
 
1569{
1570	dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1571	ceph_iterate_session_caps(session, wake_up_session_cb,
1572				  (void *)(unsigned long)ev);
1573}
1574
1575/*
1576 * Send periodic message to MDS renewing all currently held caps.  The
1577 * ack will reset the expiration for all caps from this session.
1578 *
1579 * caller holds s_mutex
1580 */
1581static int send_renew_caps(struct ceph_mds_client *mdsc,
1582			   struct ceph_mds_session *session)
1583{
1584	struct ceph_msg *msg;
1585	int state;
1586
1587	if (time_after_eq(jiffies, session->s_cap_ttl) &&
1588	    time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1589		pr_info("mds%d caps stale\n", session->s_mds);
1590	session->s_renew_requested = jiffies;
1591
1592	/* do not try to renew caps until a recovering mds has reconnected
1593	 * with its clients. */
1594	state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1595	if (state < CEPH_MDS_STATE_RECONNECT) {
1596		dout("send_renew_caps ignoring mds%d (%s)\n",
1597		     session->s_mds, ceph_mds_state_name(state));
1598		return 0;
1599	}
1600
1601	dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1602		ceph_mds_state_name(state));
1603	msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1604				 ++session->s_renew_seq);
1605	if (!msg)
1606		return -ENOMEM;
1607	ceph_con_send(&session->s_con, msg);
1608	return 0;
1609}
1610
1611static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1612			     struct ceph_mds_session *session, u64 seq)
1613{
1614	struct ceph_msg *msg;
1615
1616	dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1617	     session->s_mds, ceph_session_state_name(session->s_state), seq);
1618	msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1619	if (!msg)
1620		return -ENOMEM;
1621	ceph_con_send(&session->s_con, msg);
1622	return 0;
1623}
1624
1625
1626/*
1627 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1628 *
1629 * Called under session->s_mutex
1630 */
1631static void renewed_caps(struct ceph_mds_client *mdsc,
1632			 struct ceph_mds_session *session, int is_renew)
1633{
1634	int was_stale;
1635	int wake = 0;
1636
1637	spin_lock(&session->s_cap_lock);
1638	was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1639
1640	session->s_cap_ttl = session->s_renew_requested +
1641		mdsc->mdsmap->m_session_timeout*HZ;
1642
1643	if (was_stale) {
1644		if (time_before(jiffies, session->s_cap_ttl)) {
1645			pr_info("mds%d caps renewed\n", session->s_mds);
1646			wake = 1;
1647		} else {
1648			pr_info("mds%d caps still stale\n", session->s_mds);
1649		}
1650	}
1651	dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1652	     session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1653	     time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1654	spin_unlock(&session->s_cap_lock);
1655
1656	if (wake)
1657		wake_up_session_caps(session, RENEWCAPS);
1658}
1659
1660/*
1661 * send a session close request
1662 */
1663static int request_close_session(struct ceph_mds_client *mdsc,
1664				 struct ceph_mds_session *session)
1665{
1666	struct ceph_msg *msg;
1667
1668	dout("request_close_session mds%d state %s seq %lld\n",
1669	     session->s_mds, ceph_session_state_name(session->s_state),
1670	     session->s_seq);
1671	msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1672	if (!msg)
1673		return -ENOMEM;
1674	ceph_con_send(&session->s_con, msg);
1675	return 1;
1676}
1677
1678/*
1679 * Called with s_mutex held.
1680 */
1681static int __close_session(struct ceph_mds_client *mdsc,
1682			 struct ceph_mds_session *session)
1683{
1684	if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1685		return 0;
1686	session->s_state = CEPH_MDS_SESSION_CLOSING;
1687	return request_close_session(mdsc, session);
1688}
1689
1690static bool drop_negative_children(struct dentry *dentry)
1691{
1692	struct dentry *child;
1693	bool all_negative = true;
1694
1695	if (!d_is_dir(dentry))
1696		goto out;
1697
1698	spin_lock(&dentry->d_lock);
1699	list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1700		if (d_really_is_positive(child)) {
1701			all_negative = false;
1702			break;
1703		}
1704	}
1705	spin_unlock(&dentry->d_lock);
1706
1707	if (all_negative)
1708		shrink_dcache_parent(dentry);
1709out:
1710	return all_negative;
1711}
1712
1713/*
1714 * Trim old(er) caps.
1715 *
1716 * Because we can't cache an inode without one or more caps, we do
1717 * this indirectly: if a cap is unused, we prune its aliases, at which
1718 * point the inode will hopefully get dropped to.
1719 *
1720 * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1721 * memory pressure from the MDS, though, so it needn't be perfect.
1722 */
1723static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1724{
1725	int *remaining = arg;
1726	struct ceph_inode_info *ci = ceph_inode(inode);
1727	int used, wanted, oissued, mine;
1728
1729	if (*remaining <= 0)
1730		return -1;
1731
1732	spin_lock(&ci->i_ceph_lock);
1733	mine = cap->issued | cap->implemented;
1734	used = __ceph_caps_used(ci);
1735	wanted = __ceph_caps_file_wanted(ci);
1736	oissued = __ceph_caps_issued_other(ci, cap);
1737
1738	dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1739	     inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1740	     ceph_cap_string(used), ceph_cap_string(wanted));
1741	if (cap == ci->i_auth_cap) {
1742		if (ci->i_dirty_caps || ci->i_flushing_caps ||
1743		    !list_empty(&ci->i_cap_snaps))
1744			goto out;
1745		if ((used | wanted) & CEPH_CAP_ANY_WR)
1746			goto out;
1747		/* Note: it's possible that i_filelock_ref becomes non-zero
1748		 * after dropping auth caps. It doesn't hurt because reply
1749		 * of lock mds request will re-add auth caps. */
1750		if (atomic_read(&ci->i_filelock_ref) > 0)
1751			goto out;
1752	}
1753	/* The inode has cached pages, but it's no longer used.
1754	 * we can safely drop it */
1755	if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1756	    !(oissued & CEPH_CAP_FILE_CACHE)) {
1757	  used = 0;
1758	  oissued = 0;
1759	}
1760	if ((used | wanted) & ~oissued & mine)
1761		goto out;   /* we need these caps */
1762
 
1763	if (oissued) {
1764		/* we aren't the only cap.. just remove us */
1765		__ceph_remove_cap(cap, true);
1766		(*remaining)--;
1767	} else {
1768		struct dentry *dentry;
1769		/* try dropping referring dentries */
1770		spin_unlock(&ci->i_ceph_lock);
1771		dentry = d_find_any_alias(inode);
1772		if (dentry && drop_negative_children(dentry)) {
1773			int count;
1774			dput(dentry);
1775			d_prune_aliases(inode);
1776			count = atomic_read(&inode->i_count);
1777			if (count == 1)
1778				(*remaining)--;
1779			dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1780			     inode, cap, count);
1781		} else {
1782			dput(dentry);
1783		}
1784		return 0;
1785	}
1786
1787out:
1788	spin_unlock(&ci->i_ceph_lock);
1789	return 0;
1790}
1791
1792/*
1793 * Trim session cap count down to some max number.
1794 */
1795int ceph_trim_caps(struct ceph_mds_client *mdsc,
1796		   struct ceph_mds_session *session,
1797		   int max_caps)
1798{
1799	int trim_caps = session->s_nr_caps - max_caps;
1800
1801	dout("trim_caps mds%d start: %d / %d, trim %d\n",
1802	     session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1803	if (trim_caps > 0) {
1804		int remaining = trim_caps;
1805
1806		ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
1807		dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1808		     session->s_mds, session->s_nr_caps, max_caps,
1809			trim_caps - remaining);
 
1810	}
1811
1812	ceph_flush_cap_releases(mdsc, session);
1813	return 0;
1814}
1815
1816static int check_caps_flush(struct ceph_mds_client *mdsc,
1817			    u64 want_flush_tid)
1818{
1819	int ret = 1;
1820
1821	spin_lock(&mdsc->cap_dirty_lock);
1822	if (!list_empty(&mdsc->cap_flush_list)) {
1823		struct ceph_cap_flush *cf =
1824			list_first_entry(&mdsc->cap_flush_list,
1825					 struct ceph_cap_flush, g_list);
1826		if (cf->tid <= want_flush_tid) {
1827			dout("check_caps_flush still flushing tid "
1828			     "%llu <= %llu\n", cf->tid, want_flush_tid);
1829			ret = 0;
1830		}
1831	}
1832	spin_unlock(&mdsc->cap_dirty_lock);
1833	return ret;
1834}
1835
1836/*
1837 * flush all dirty inode data to disk.
1838 *
1839 * returns true if we've flushed through want_flush_tid
1840 */
1841static void wait_caps_flush(struct ceph_mds_client *mdsc,
1842			    u64 want_flush_tid)
1843{
1844	dout("check_caps_flush want %llu\n", want_flush_tid);
1845
1846	wait_event(mdsc->cap_flushing_wq,
1847		   check_caps_flush(mdsc, want_flush_tid));
1848
1849	dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1850}
1851
1852/*
1853 * called under s_mutex
1854 */
1855static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1856				   struct ceph_mds_session *session)
1857{
1858	struct ceph_msg *msg = NULL;
1859	struct ceph_mds_cap_release *head;
1860	struct ceph_mds_cap_item *item;
1861	struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
1862	struct ceph_cap *cap;
1863	LIST_HEAD(tmp_list);
1864	int num_cap_releases;
1865	__le32	barrier, *cap_barrier;
1866
1867	down_read(&osdc->lock);
1868	barrier = cpu_to_le32(osdc->epoch_barrier);
1869	up_read(&osdc->lock);
1870
1871	spin_lock(&session->s_cap_lock);
1872again:
1873	list_splice_init(&session->s_cap_releases, &tmp_list);
1874	num_cap_releases = session->s_num_cap_releases;
1875	session->s_num_cap_releases = 0;
1876	spin_unlock(&session->s_cap_lock);
1877
1878	while (!list_empty(&tmp_list)) {
1879		if (!msg) {
1880			msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1881					PAGE_SIZE, GFP_NOFS, false);
1882			if (!msg)
1883				goto out_err;
1884			head = msg->front.iov_base;
1885			head->num = cpu_to_le32(0);
1886			msg->front.iov_len = sizeof(*head);
1887
1888			msg->hdr.version = cpu_to_le16(2);
1889			msg->hdr.compat_version = cpu_to_le16(1);
1890		}
1891
1892		cap = list_first_entry(&tmp_list, struct ceph_cap,
1893					session_caps);
1894		list_del(&cap->session_caps);
1895		num_cap_releases--;
1896
1897		head = msg->front.iov_base;
1898		put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
1899				   &head->num);
1900		item = msg->front.iov_base + msg->front.iov_len;
1901		item->ino = cpu_to_le64(cap->cap_ino);
1902		item->cap_id = cpu_to_le64(cap->cap_id);
1903		item->migrate_seq = cpu_to_le32(cap->mseq);
1904		item->seq = cpu_to_le32(cap->issue_seq);
1905		msg->front.iov_len += sizeof(*item);
1906
1907		ceph_put_cap(mdsc, cap);
1908
1909		if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1910			// Append cap_barrier field
1911			cap_barrier = msg->front.iov_base + msg->front.iov_len;
1912			*cap_barrier = barrier;
1913			msg->front.iov_len += sizeof(*cap_barrier);
1914
1915			msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1916			dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1917			ceph_con_send(&session->s_con, msg);
1918			msg = NULL;
1919		}
1920	}
1921
1922	BUG_ON(num_cap_releases != 0);
1923
1924	spin_lock(&session->s_cap_lock);
1925	if (!list_empty(&session->s_cap_releases))
1926		goto again;
1927	spin_unlock(&session->s_cap_lock);
1928
1929	if (msg) {
1930		// Append cap_barrier field
1931		cap_barrier = msg->front.iov_base + msg->front.iov_len;
1932		*cap_barrier = barrier;
1933		msg->front.iov_len += sizeof(*cap_barrier);
1934
1935		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1936		dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1937		ceph_con_send(&session->s_con, msg);
1938	}
1939	return;
1940out_err:
1941	pr_err("send_cap_releases mds%d, failed to allocate message\n",
1942		session->s_mds);
1943	spin_lock(&session->s_cap_lock);
1944	list_splice(&tmp_list, &session->s_cap_releases);
1945	session->s_num_cap_releases += num_cap_releases;
1946	spin_unlock(&session->s_cap_lock);
1947}
1948
1949static void ceph_cap_release_work(struct work_struct *work)
1950{
1951	struct ceph_mds_session *session =
1952		container_of(work, struct ceph_mds_session, s_cap_release_work);
1953
1954	mutex_lock(&session->s_mutex);
1955	if (session->s_state == CEPH_MDS_SESSION_OPEN ||
1956	    session->s_state == CEPH_MDS_SESSION_HUNG)
1957		ceph_send_cap_releases(session->s_mdsc, session);
1958	mutex_unlock(&session->s_mutex);
1959	ceph_put_mds_session(session);
1960}
1961
1962void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
1963		             struct ceph_mds_session *session)
1964{
1965	if (mdsc->stopping)
1966		return;
1967
1968	get_session(session);
1969	if (queue_work(mdsc->fsc->cap_wq,
1970		       &session->s_cap_release_work)) {
1971		dout("cap release work queued\n");
1972	} else {
1973		ceph_put_mds_session(session);
1974		dout("failed to queue cap release work\n");
1975	}
1976}
1977
1978/*
1979 * caller holds session->s_cap_lock
1980 */
1981void __ceph_queue_cap_release(struct ceph_mds_session *session,
1982			      struct ceph_cap *cap)
1983{
1984	list_add_tail(&cap->session_caps, &session->s_cap_releases);
1985	session->s_num_cap_releases++;
1986
1987	if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
1988		ceph_flush_cap_releases(session->s_mdsc, session);
1989}
1990
1991static void ceph_cap_reclaim_work(struct work_struct *work)
1992{
1993	struct ceph_mds_client *mdsc =
1994		container_of(work, struct ceph_mds_client, cap_reclaim_work);
1995	int ret = ceph_trim_dentries(mdsc);
1996	if (ret == -EAGAIN)
1997		ceph_queue_cap_reclaim_work(mdsc);
1998}
1999
2000void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2001{
2002	if (mdsc->stopping)
2003		return;
2004
2005        if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2006                dout("caps reclaim work queued\n");
2007        } else {
2008                dout("failed to queue caps release work\n");
2009        }
2010}
2011
2012void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2013{
2014	int val;
2015	if (!nr)
2016		return;
2017	val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2018	if (!(val % CEPH_CAPS_PER_RELEASE)) {
2019		atomic_set(&mdsc->cap_reclaim_pending, 0);
2020		ceph_queue_cap_reclaim_work(mdsc);
2021	}
2022}
2023
2024/*
2025 * requests
2026 */
2027
2028int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2029				    struct inode *dir)
2030{
2031	struct ceph_inode_info *ci = ceph_inode(dir);
2032	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2033	struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2034	size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2035	int order, num_entries;
2036
2037	spin_lock(&ci->i_ceph_lock);
2038	num_entries = ci->i_files + ci->i_subdirs;
2039	spin_unlock(&ci->i_ceph_lock);
2040	num_entries = max(num_entries, 1);
2041	num_entries = min(num_entries, opt->max_readdir);
2042
2043	order = get_order(size * num_entries);
2044	while (order >= 0) {
2045		rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2046							     __GFP_NOWARN,
2047							     order);
2048		if (rinfo->dir_entries)
2049			break;
2050		order--;
2051	}
2052	if (!rinfo->dir_entries)
2053		return -ENOMEM;
2054
2055	num_entries = (PAGE_SIZE << order) / size;
2056	num_entries = min(num_entries, opt->max_readdir);
2057
2058	rinfo->dir_buf_size = PAGE_SIZE << order;
2059	req->r_num_caps = num_entries + 1;
2060	req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2061	req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2062	return 0;
2063}
2064
2065/*
2066 * Create an mds request.
2067 */
2068struct ceph_mds_request *
2069ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2070{
2071	struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
2072	struct timespec64 ts;
2073
2074	if (!req)
2075		return ERR_PTR(-ENOMEM);
2076
2077	mutex_init(&req->r_fill_mutex);
2078	req->r_mdsc = mdsc;
2079	req->r_started = jiffies;
2080	req->r_resend_mds = -1;
2081	INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2082	INIT_LIST_HEAD(&req->r_unsafe_target_item);
2083	req->r_fmode = -1;
2084	kref_init(&req->r_kref);
2085	RB_CLEAR_NODE(&req->r_node);
2086	INIT_LIST_HEAD(&req->r_wait);
2087	init_completion(&req->r_completion);
2088	init_completion(&req->r_safe_completion);
2089	INIT_LIST_HEAD(&req->r_unsafe_item);
2090
2091	ktime_get_coarse_real_ts64(&ts);
2092	req->r_stamp = timespec64_trunc(ts, mdsc->fsc->sb->s_time_gran);
2093
2094	req->r_op = op;
2095	req->r_direct_mode = mode;
2096	return req;
2097}
2098
2099/*
2100 * return oldest (lowest) request, tid in request tree, 0 if none.
2101 *
2102 * called under mdsc->mutex.
2103 */
2104static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2105{
2106	if (RB_EMPTY_ROOT(&mdsc->request_tree))
2107		return NULL;
2108	return rb_entry(rb_first(&mdsc->request_tree),
2109			struct ceph_mds_request, r_node);
2110}
2111
2112static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2113{
2114	return mdsc->oldest_tid;
2115}
2116
2117/*
2118 * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2119 * on build_path_from_dentry in fs/cifs/dir.c.
2120 *
2121 * If @stop_on_nosnap, generate path relative to the first non-snapped
2122 * inode.
2123 *
2124 * Encode hidden .snap dirs as a double /, i.e.
2125 *   foo/.snap/bar -> foo//bar
2126 */
2127char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2128			   int stop_on_nosnap)
2129{
2130	struct dentry *temp;
2131	char *path;
2132	int pos;
2133	unsigned seq;
2134	u64 base;
2135
2136	if (!dentry)
2137		return ERR_PTR(-EINVAL);
2138
2139	path = __getname();
2140	if (!path)
2141		return ERR_PTR(-ENOMEM);
2142retry:
2143	pos = PATH_MAX - 1;
2144	path[pos] = '\0';
2145
2146	seq = read_seqbegin(&rename_lock);
2147	rcu_read_lock();
2148	temp = dentry;
2149	for (;;) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2150		struct inode *inode;
2151
2152		spin_lock(&temp->d_lock);
2153		inode = d_inode(temp);
2154		if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2155			dout("build_path path+%d: %p SNAPDIR\n",
2156			     pos, temp);
2157		} else if (stop_on_nosnap && inode && dentry != temp &&
2158			   ceph_snap(inode) == CEPH_NOSNAP) {
2159			spin_unlock(&temp->d_lock);
2160			pos++; /* get rid of any prepended '/' */
2161			break;
2162		} else {
2163			pos -= temp->d_name.len;
2164			if (pos < 0) {
2165				spin_unlock(&temp->d_lock);
2166				break;
2167			}
2168			memcpy(path + pos, temp->d_name.name, temp->d_name.len);
 
2169		}
2170		spin_unlock(&temp->d_lock);
2171		temp = READ_ONCE(temp->d_parent);
2172
2173		/* Are we at the root? */
2174		if (IS_ROOT(temp))
2175			break;
2176
2177		/* Are we out of buffer? */
2178		if (--pos < 0)
2179			break;
2180
2181		path[pos] = '/';
2182	}
2183	base = ceph_ino(d_inode(temp));
2184	rcu_read_unlock();
2185	if (pos < 0 || read_seqretry(&rename_lock, seq)) {
2186		pr_err("build_path did not end path lookup where "
2187		       "expected, pos is %d\n", pos);
2188		/* presumably this is only possible if racing with a
2189		   rename of one of the parent directories (we can not
2190		   lock the dentries above us to prevent this, but
2191		   retrying should be harmless) */
 
2192		goto retry;
2193	}
2194
2195	*pbase = base;
2196	*plen = PATH_MAX - 1 - pos;
2197	dout("build_path on %p %d built %llx '%.*s'\n",
2198	     dentry, d_count(dentry), base, *plen, path + pos);
2199	return path + pos;
2200}
2201
2202static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2203			     const char **ppath, int *ppathlen, u64 *pino,
2204			     bool *pfreepath, bool parent_locked)
2205{
2206	char *path;
2207
2208	rcu_read_lock();
2209	if (!dir)
2210		dir = d_inode_rcu(dentry->d_parent);
2211	if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2212		*pino = ceph_ino(dir);
2213		rcu_read_unlock();
2214		*ppath = dentry->d_name.name;
2215		*ppathlen = dentry->d_name.len;
2216		return 0;
2217	}
2218	rcu_read_unlock();
2219	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2220	if (IS_ERR(path))
2221		return PTR_ERR(path);
2222	*ppath = path;
2223	*pfreepath = true;
2224	return 0;
2225}
2226
2227static int build_inode_path(struct inode *inode,
2228			    const char **ppath, int *ppathlen, u64 *pino,
2229			    bool *pfreepath)
2230{
2231	struct dentry *dentry;
2232	char *path;
2233
2234	if (ceph_snap(inode) == CEPH_NOSNAP) {
2235		*pino = ceph_ino(inode);
2236		*ppathlen = 0;
2237		return 0;
2238	}
2239	dentry = d_find_alias(inode);
2240	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2241	dput(dentry);
2242	if (IS_ERR(path))
2243		return PTR_ERR(path);
2244	*ppath = path;
2245	*pfreepath = true;
2246	return 0;
2247}
2248
2249/*
2250 * request arguments may be specified via an inode *, a dentry *, or
2251 * an explicit ino+path.
2252 */
2253static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2254				  struct inode *rdiri, const char *rpath,
2255				  u64 rino, const char **ppath, int *pathlen,
2256				  u64 *ino, bool *freepath, bool parent_locked)
2257{
2258	int r = 0;
2259
2260	if (rinode) {
2261		r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2262		dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2263		     ceph_snap(rinode));
2264	} else if (rdentry) {
2265		r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2266					freepath, parent_locked);
2267		dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2268		     *ppath);
2269	} else if (rpath || rino) {
2270		*ino = rino;
2271		*ppath = rpath;
2272		*pathlen = rpath ? strlen(rpath) : 0;
2273		dout(" path %.*s\n", *pathlen, rpath);
2274	}
2275
2276	return r;
2277}
2278
2279/*
2280 * called under mdsc->mutex
2281 */
2282static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
2283					       struct ceph_mds_request *req,
2284					       int mds, bool drop_cap_releases)
2285{
2286	struct ceph_msg *msg;
2287	struct ceph_mds_request_head *head;
2288	const char *path1 = NULL;
2289	const char *path2 = NULL;
2290	u64 ino1 = 0, ino2 = 0;
2291	int pathlen1 = 0, pathlen2 = 0;
2292	bool freepath1 = false, freepath2 = false;
2293	int len;
2294	u16 releases;
2295	void *p, *end;
2296	int ret;
2297
2298	ret = set_request_path_attr(req->r_inode, req->r_dentry,
2299			      req->r_parent, req->r_path1, req->r_ino1.ino,
2300			      &path1, &pathlen1, &ino1, &freepath1,
2301			      test_bit(CEPH_MDS_R_PARENT_LOCKED,
2302					&req->r_req_flags));
2303	if (ret < 0) {
2304		msg = ERR_PTR(ret);
2305		goto out;
2306	}
2307
2308	/* If r_old_dentry is set, then assume that its parent is locked */
2309	ret = set_request_path_attr(NULL, req->r_old_dentry,
2310			      req->r_old_dentry_dir,
2311			      req->r_path2, req->r_ino2.ino,
2312			      &path2, &pathlen2, &ino2, &freepath2, true);
2313	if (ret < 0) {
2314		msg = ERR_PTR(ret);
2315		goto out_free1;
2316	}
2317
2318	len = sizeof(*head) +
2319		pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2320		sizeof(struct ceph_timespec);
2321
2322	/* calculate (max) length for cap releases */
2323	len += sizeof(struct ceph_mds_request_release) *
2324		(!!req->r_inode_drop + !!req->r_dentry_drop +
2325		 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2326	if (req->r_dentry_drop)
2327		len += pathlen1;
2328	if (req->r_old_dentry_drop)
2329		len += pathlen2;
2330
2331	msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2332	if (!msg) {
2333		msg = ERR_PTR(-ENOMEM);
2334		goto out_free2;
2335	}
2336
2337	msg->hdr.version = cpu_to_le16(2);
2338	msg->hdr.tid = cpu_to_le64(req->r_tid);
2339
2340	head = msg->front.iov_base;
2341	p = msg->front.iov_base + sizeof(*head);
2342	end = msg->front.iov_base + msg->front.iov_len;
2343
2344	head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2345	head->op = cpu_to_le32(req->r_op);
2346	head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
2347	head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
2348	head->args = req->r_args;
2349
2350	ceph_encode_filepath(&p, end, ino1, path1);
2351	ceph_encode_filepath(&p, end, ino2, path2);
2352
2353	/* make note of release offset, in case we need to replay */
2354	req->r_request_release_offset = p - msg->front.iov_base;
2355
2356	/* cap releases */
2357	releases = 0;
2358	if (req->r_inode_drop)
2359		releases += ceph_encode_inode_release(&p,
2360		      req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2361		      mds, req->r_inode_drop, req->r_inode_unless, 0);
2362	if (req->r_dentry_drop)
2363		releases += ceph_encode_dentry_release(&p, req->r_dentry,
2364				req->r_parent, mds, req->r_dentry_drop,
2365				req->r_dentry_unless);
2366	if (req->r_old_dentry_drop)
2367		releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2368				req->r_old_dentry_dir, mds,
2369				req->r_old_dentry_drop,
2370				req->r_old_dentry_unless);
2371	if (req->r_old_inode_drop)
2372		releases += ceph_encode_inode_release(&p,
2373		      d_inode(req->r_old_dentry),
2374		      mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2375
2376	if (drop_cap_releases) {
2377		releases = 0;
2378		p = msg->front.iov_base + req->r_request_release_offset;
2379	}
2380
2381	head->num_releases = cpu_to_le16(releases);
2382
2383	/* time stamp */
2384	{
2385		struct ceph_timespec ts;
2386		ceph_encode_timespec64(&ts, &req->r_stamp);
2387		ceph_encode_copy(&p, &ts, sizeof(ts));
2388	}
2389
2390	BUG_ON(p > end);
2391	msg->front.iov_len = p - msg->front.iov_base;
2392	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2393
2394	if (req->r_pagelist) {
2395		struct ceph_pagelist *pagelist = req->r_pagelist;
 
2396		ceph_msg_data_add_pagelist(msg, pagelist);
2397		msg->hdr.data_len = cpu_to_le32(pagelist->length);
2398	} else {
2399		msg->hdr.data_len = 0;
2400	}
2401
2402	msg->hdr.data_off = cpu_to_le16(0);
2403
2404out_free2:
2405	if (freepath2)
2406		ceph_mdsc_free_path((char *)path2, pathlen2);
2407out_free1:
2408	if (freepath1)
2409		ceph_mdsc_free_path((char *)path1, pathlen1);
2410out:
2411	return msg;
2412}
2413
2414/*
2415 * called under mdsc->mutex if error, under no mutex if
2416 * success.
2417 */
2418static void complete_request(struct ceph_mds_client *mdsc,
2419			     struct ceph_mds_request *req)
2420{
2421	if (req->r_callback)
2422		req->r_callback(mdsc, req);
2423	complete_all(&req->r_completion);
 
2424}
2425
2426/*
2427 * called under mdsc->mutex
2428 */
2429static int __prepare_send_request(struct ceph_mds_client *mdsc,
2430				  struct ceph_mds_request *req,
2431				  int mds, bool drop_cap_releases)
2432{
2433	struct ceph_mds_request_head *rhead;
2434	struct ceph_msg *msg;
2435	int flags = 0;
2436
2437	req->r_attempts++;
2438	if (req->r_inode) {
2439		struct ceph_cap *cap =
2440			ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2441
2442		if (cap)
2443			req->r_sent_on_mseq = cap->mseq;
2444		else
2445			req->r_sent_on_mseq = -1;
2446	}
2447	dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2448	     req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2449
2450	if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2451		void *p;
2452		/*
2453		 * Replay.  Do not regenerate message (and rebuild
2454		 * paths, etc.); just use the original message.
2455		 * Rebuilding paths will break for renames because
2456		 * d_move mangles the src name.
2457		 */
2458		msg = req->r_request;
2459		rhead = msg->front.iov_base;
2460
2461		flags = le32_to_cpu(rhead->flags);
2462		flags |= CEPH_MDS_FLAG_REPLAY;
2463		rhead->flags = cpu_to_le32(flags);
2464
2465		if (req->r_target_inode)
2466			rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2467
2468		rhead->num_retry = req->r_attempts - 1;
2469
2470		/* remove cap/dentry releases from message */
2471		rhead->num_releases = 0;
2472
2473		/* time stamp */
2474		p = msg->front.iov_base + req->r_request_release_offset;
2475		{
2476			struct ceph_timespec ts;
2477			ceph_encode_timespec64(&ts, &req->r_stamp);
2478			ceph_encode_copy(&p, &ts, sizeof(ts));
2479		}
2480
2481		msg->front.iov_len = p - msg->front.iov_base;
2482		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2483		return 0;
2484	}
2485
2486	if (req->r_request) {
2487		ceph_msg_put(req->r_request);
2488		req->r_request = NULL;
2489	}
2490	msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2491	if (IS_ERR(msg)) {
2492		req->r_err = PTR_ERR(msg);
2493		return PTR_ERR(msg);
2494	}
2495	req->r_request = msg;
2496
2497	rhead = msg->front.iov_base;
2498	rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2499	if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2500		flags |= CEPH_MDS_FLAG_REPLAY;
2501	if (req->r_parent)
2502		flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2503	rhead->flags = cpu_to_le32(flags);
2504	rhead->num_fwd = req->r_num_fwd;
2505	rhead->num_retry = req->r_attempts - 1;
2506	rhead->ino = 0;
2507
2508	dout(" r_parent = %p\n", req->r_parent);
2509	return 0;
2510}
2511
2512/*
2513 * send request, or put it on the appropriate wait list.
2514 */
2515static void __do_request(struct ceph_mds_client *mdsc,
2516			struct ceph_mds_request *req)
2517{
2518	struct ceph_mds_session *session = NULL;
2519	int mds = -1;
2520	int err = 0;
2521
2522	if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2523		if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2524			__unregister_request(mdsc, req);
2525		return;
2526	}
2527
2528	if (req->r_timeout &&
2529	    time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2530		dout("do_request timed out\n");
2531		err = -EIO;
2532		goto finish;
2533	}
2534	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2535		dout("do_request forced umount\n");
2536		err = -EIO;
2537		goto finish;
2538	}
2539	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2540		if (mdsc->mdsmap_err) {
2541			err = mdsc->mdsmap_err;
2542			dout("do_request mdsmap err %d\n", err);
2543			goto finish;
2544		}
2545		if (mdsc->mdsmap->m_epoch == 0) {
2546			dout("do_request no mdsmap, waiting for map\n");
2547			list_add(&req->r_wait, &mdsc->waiting_for_map);
2548			return;
2549		}
2550		if (!(mdsc->fsc->mount_options->flags &
2551		      CEPH_MOUNT_OPT_MOUNTWAIT) &&
2552		    !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2553			err = -ENOENT;
2554			pr_info("probably no mds server is up\n");
2555			goto finish;
2556		}
2557	}
2558
2559	put_request_session(req);
2560
2561	mds = __choose_mds(mdsc, req);
2562	if (mds < 0 ||
2563	    ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2564		dout("do_request no mds or not active, waiting for map\n");
2565		list_add(&req->r_wait, &mdsc->waiting_for_map);
2566		return;
2567	}
2568
2569	/* get, open session */
2570	session = __ceph_lookup_mds_session(mdsc, mds);
2571	if (!session) {
2572		session = register_session(mdsc, mds);
2573		if (IS_ERR(session)) {
2574			err = PTR_ERR(session);
2575			goto finish;
2576		}
2577	}
2578	req->r_session = get_session(session);
2579
2580	dout("do_request mds%d session %p state %s\n", mds, session,
2581	     ceph_session_state_name(session->s_state));
2582	if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2583	    session->s_state != CEPH_MDS_SESSION_HUNG) {
2584		if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2585			err = -EACCES;
2586			goto out_session;
2587		}
2588		if (session->s_state == CEPH_MDS_SESSION_NEW ||
2589		    session->s_state == CEPH_MDS_SESSION_CLOSING)
2590			__open_session(mdsc, session);
2591		list_add(&req->r_wait, &session->s_waiting);
2592		goto out_session;
2593	}
2594
2595	/* send request */
2596	req->r_resend_mds = -1;   /* forget any previous mds hint */
2597
2598	if (req->r_request_started == 0)   /* note request start time */
2599		req->r_request_started = jiffies;
2600
2601	err = __prepare_send_request(mdsc, req, mds, false);
2602	if (!err) {
2603		ceph_msg_get(req->r_request);
2604		ceph_con_send(&session->s_con, req->r_request);
2605	}
2606
2607out_session:
2608	ceph_put_mds_session(session);
2609finish:
2610	if (err) {
2611		dout("__do_request early error %d\n", err);
2612		req->r_err = err;
2613		complete_request(mdsc, req);
2614		__unregister_request(mdsc, req);
2615	}
2616	return;
 
2617}
2618
2619/*
2620 * called under mdsc->mutex
2621 */
2622static void __wake_requests(struct ceph_mds_client *mdsc,
2623			    struct list_head *head)
2624{
2625	struct ceph_mds_request *req;
2626	LIST_HEAD(tmp_list);
2627
2628	list_splice_init(head, &tmp_list);
2629
2630	while (!list_empty(&tmp_list)) {
2631		req = list_entry(tmp_list.next,
2632				 struct ceph_mds_request, r_wait);
2633		list_del_init(&req->r_wait);
2634		dout(" wake request %p tid %llu\n", req, req->r_tid);
2635		__do_request(mdsc, req);
2636	}
2637}
2638
2639/*
2640 * Wake up threads with requests pending for @mds, so that they can
2641 * resubmit their requests to a possibly different mds.
2642 */
2643static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2644{
2645	struct ceph_mds_request *req;
2646	struct rb_node *p = rb_first(&mdsc->request_tree);
2647
2648	dout("kick_requests mds%d\n", mds);
2649	while (p) {
2650		req = rb_entry(p, struct ceph_mds_request, r_node);
2651		p = rb_next(p);
2652		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2653			continue;
2654		if (req->r_attempts > 0)
2655			continue; /* only new requests */
2656		if (req->r_session &&
2657		    req->r_session->s_mds == mds) {
2658			dout(" kicking tid %llu\n", req->r_tid);
2659			list_del_init(&req->r_wait);
2660			__do_request(mdsc, req);
2661		}
2662	}
2663}
2664
2665int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2666			      struct ceph_mds_request *req)
2667{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2668	int err;
2669
2670	/* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
 
 
2671	if (req->r_inode)
2672		ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2673	if (req->r_parent)
2674		ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
2675	if (req->r_old_dentry_dir)
2676		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2677				  CEPH_CAP_PIN);
2678
2679	dout("submit_request on %p for inode %p\n", req, dir);
2680	mutex_lock(&mdsc->mutex);
2681	__register_request(mdsc, req, dir);
2682	__do_request(mdsc, req);
2683	err = req->r_err;
2684	mutex_unlock(&mdsc->mutex);
2685	return err;
2686}
2687
2688static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
2689				  struct ceph_mds_request *req)
2690{
2691	int err;
2692
2693	/* wait */
 
2694	dout("do_request waiting\n");
2695	if (!req->r_timeout && req->r_wait_for_completion) {
2696		err = req->r_wait_for_completion(mdsc, req);
2697	} else {
2698		long timeleft = wait_for_completion_killable_timeout(
2699					&req->r_completion,
2700					ceph_timeout_jiffies(req->r_timeout));
2701		if (timeleft > 0)
2702			err = 0;
2703		else if (!timeleft)
2704			err = -EIO;  /* timed out */
2705		else
2706			err = timeleft;  /* killed */
2707	}
2708	dout("do_request waited, got %d\n", err);
2709	mutex_lock(&mdsc->mutex);
2710
2711	/* only abort if we didn't race with a real reply */
2712	if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2713		err = le32_to_cpu(req->r_reply_info.head->result);
2714	} else if (err < 0) {
2715		dout("aborted request %lld with %d\n", req->r_tid, err);
2716
2717		/*
2718		 * ensure we aren't running concurrently with
2719		 * ceph_fill_trace or ceph_readdir_prepopulate, which
2720		 * rely on locks (dir mutex) held by our caller.
2721		 */
2722		mutex_lock(&req->r_fill_mutex);
2723		req->r_err = err;
2724		set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2725		mutex_unlock(&req->r_fill_mutex);
2726
2727		if (req->r_parent &&
2728		    (req->r_op & CEPH_MDS_OP_WRITE))
2729			ceph_invalidate_dir_request(req);
2730	} else {
2731		err = req->r_err;
2732	}
2733
 
2734	mutex_unlock(&mdsc->mutex);
2735	return err;
2736}
2737
2738/*
2739 * Synchrously perform an mds request.  Take care of all of the
2740 * session setup, forwarding, retry details.
2741 */
2742int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2743			 struct inode *dir,
2744			 struct ceph_mds_request *req)
2745{
2746	int err;
2747
2748	dout("do_request on %p\n", req);
2749
2750	/* issue */
2751	err = ceph_mdsc_submit_request(mdsc, dir, req);
2752	if (!err)
2753		err = ceph_mdsc_wait_request(mdsc, req);
2754	dout("do_request %p done, result %d\n", req, err);
2755	return err;
2756}
2757
2758/*
2759 * Invalidate dir's completeness, dentry lease state on an aborted MDS
2760 * namespace request.
2761 */
2762void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2763{
2764	struct inode *dir = req->r_parent;
2765	struct inode *old_dir = req->r_old_dentry_dir;
2766
2767	dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
2768
2769	ceph_dir_clear_complete(dir);
2770	if (old_dir)
2771		ceph_dir_clear_complete(old_dir);
2772	if (req->r_dentry)
2773		ceph_invalidate_dentry_lease(req->r_dentry);
2774	if (req->r_old_dentry)
2775		ceph_invalidate_dentry_lease(req->r_old_dentry);
2776}
2777
2778/*
2779 * Handle mds reply.
2780 *
2781 * We take the session mutex and parse and process the reply immediately.
2782 * This preserves the logical ordering of replies, capabilities, etc., sent
2783 * by the MDS as they are applied to our local cache.
2784 */
2785static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2786{
2787	struct ceph_mds_client *mdsc = session->s_mdsc;
2788	struct ceph_mds_request *req;
2789	struct ceph_mds_reply_head *head = msg->front.iov_base;
2790	struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2791	struct ceph_snap_realm *realm;
2792	u64 tid;
2793	int err, result;
2794	int mds = session->s_mds;
2795
2796	if (msg->front.iov_len < sizeof(*head)) {
2797		pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2798		ceph_msg_dump(msg);
2799		return;
2800	}
2801
2802	/* get request, session */
2803	tid = le64_to_cpu(msg->hdr.tid);
2804	mutex_lock(&mdsc->mutex);
2805	req = lookup_get_request(mdsc, tid);
2806	if (!req) {
2807		dout("handle_reply on unknown tid %llu\n", tid);
2808		mutex_unlock(&mdsc->mutex);
2809		return;
2810	}
2811	dout("handle_reply %p\n", req);
2812
2813	/* correct session? */
2814	if (req->r_session != session) {
2815		pr_err("mdsc_handle_reply got %llu on session mds%d"
2816		       " not mds%d\n", tid, session->s_mds,
2817		       req->r_session ? req->r_session->s_mds : -1);
2818		mutex_unlock(&mdsc->mutex);
2819		goto out;
2820	}
2821
2822	/* dup? */
2823	if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
2824	    (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
2825		pr_warn("got a dup %s reply on %llu from mds%d\n",
2826			   head->safe ? "safe" : "unsafe", tid, mds);
2827		mutex_unlock(&mdsc->mutex);
2828		goto out;
2829	}
2830	if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
2831		pr_warn("got unsafe after safe on %llu from mds%d\n",
2832			   tid, mds);
2833		mutex_unlock(&mdsc->mutex);
2834		goto out;
2835	}
2836
2837	result = le32_to_cpu(head->result);
2838
2839	/*
2840	 * Handle an ESTALE
2841	 * if we're not talking to the authority, send to them
2842	 * if the authority has changed while we weren't looking,
2843	 * send to new authority
2844	 * Otherwise we just have to return an ESTALE
2845	 */
2846	if (result == -ESTALE) {
2847		dout("got ESTALE on request %llu\n", req->r_tid);
2848		req->r_resend_mds = -1;
2849		if (req->r_direct_mode != USE_AUTH_MDS) {
2850			dout("not using auth, setting for that now\n");
2851			req->r_direct_mode = USE_AUTH_MDS;
2852			__do_request(mdsc, req);
2853			mutex_unlock(&mdsc->mutex);
2854			goto out;
2855		} else  {
2856			int mds = __choose_mds(mdsc, req);
2857			if (mds >= 0 && mds != req->r_session->s_mds) {
2858				dout("but auth changed, so resending\n");
2859				__do_request(mdsc, req);
2860				mutex_unlock(&mdsc->mutex);
2861				goto out;
2862			}
2863		}
2864		dout("have to return ESTALE on request %llu\n", req->r_tid);
2865	}
2866
2867
2868	if (head->safe) {
2869		set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
2870		__unregister_request(mdsc, req);
2871
2872		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2873			/*
2874			 * We already handled the unsafe response, now do the
2875			 * cleanup.  No need to examine the response; the MDS
2876			 * doesn't include any result info in the safe
2877			 * response.  And even if it did, there is nothing
2878			 * useful we could do with a revised return value.
2879			 */
2880			dout("got safe reply %llu, mds%d\n", tid, mds);
2881
2882			/* last unsafe request during umount? */
2883			if (mdsc->stopping && !__get_oldest_req(mdsc))
2884				complete_all(&mdsc->safe_umount_waiters);
2885			mutex_unlock(&mdsc->mutex);
2886			goto out;
2887		}
2888	} else {
2889		set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
2890		list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2891		if (req->r_unsafe_dir) {
2892			struct ceph_inode_info *ci =
2893					ceph_inode(req->r_unsafe_dir);
2894			spin_lock(&ci->i_unsafe_lock);
2895			list_add_tail(&req->r_unsafe_dir_item,
2896				      &ci->i_unsafe_dirops);
2897			spin_unlock(&ci->i_unsafe_lock);
2898		}
2899	}
2900
2901	dout("handle_reply tid %lld result %d\n", tid, result);
2902	rinfo = &req->r_reply_info;
2903	if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
2904		err = parse_reply_info(msg, rinfo, (u64)-1);
2905	else
2906		err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2907	mutex_unlock(&mdsc->mutex);
2908
2909	mutex_lock(&session->s_mutex);
2910	if (err < 0) {
2911		pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2912		ceph_msg_dump(msg);
2913		goto out_err;
2914	}
2915
2916	/* snap trace */
2917	realm = NULL;
2918	if (rinfo->snapblob_len) {
2919		down_write(&mdsc->snap_rwsem);
2920		ceph_update_snap_trace(mdsc, rinfo->snapblob,
2921				rinfo->snapblob + rinfo->snapblob_len,
2922				le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2923				&realm);
2924		downgrade_write(&mdsc->snap_rwsem);
2925	} else {
2926		down_read(&mdsc->snap_rwsem);
2927	}
2928
2929	/* insert trace into our cache */
2930	mutex_lock(&req->r_fill_mutex);
2931	current->journal_info = req;
2932	err = ceph_fill_trace(mdsc->fsc->sb, req);
2933	if (err == 0) {
2934		if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2935				    req->r_op == CEPH_MDS_OP_LSSNAP))
2936			ceph_readdir_prepopulate(req, req->r_session);
 
2937	}
2938	current->journal_info = NULL;
2939	mutex_unlock(&req->r_fill_mutex);
2940
2941	up_read(&mdsc->snap_rwsem);
2942	if (realm)
2943		ceph_put_snap_realm(mdsc, realm);
2944
2945	if (err == 0) {
2946		if (req->r_target_inode &&
2947		    test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2948			struct ceph_inode_info *ci =
2949				ceph_inode(req->r_target_inode);
2950			spin_lock(&ci->i_unsafe_lock);
2951			list_add_tail(&req->r_unsafe_target_item,
2952				      &ci->i_unsafe_iops);
2953			spin_unlock(&ci->i_unsafe_lock);
2954		}
2955
2956		ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2957	}
2958out_err:
2959	mutex_lock(&mdsc->mutex);
2960	if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2961		if (err) {
2962			req->r_err = err;
2963		} else {
2964			req->r_reply =  ceph_msg_get(msg);
2965			set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
2966		}
2967	} else {
2968		dout("reply arrived after request %lld was aborted\n", tid);
2969	}
2970	mutex_unlock(&mdsc->mutex);
2971
2972	mutex_unlock(&session->s_mutex);
2973
2974	/* kick calling process */
2975	complete_request(mdsc, req);
2976out:
2977	ceph_mdsc_put_request(req);
2978	return;
2979}
2980
2981
2982
2983/*
2984 * handle mds notification that our request has been forwarded.
2985 */
2986static void handle_forward(struct ceph_mds_client *mdsc,
2987			   struct ceph_mds_session *session,
2988			   struct ceph_msg *msg)
2989{
2990	struct ceph_mds_request *req;
2991	u64 tid = le64_to_cpu(msg->hdr.tid);
2992	u32 next_mds;
2993	u32 fwd_seq;
2994	int err = -EINVAL;
2995	void *p = msg->front.iov_base;
2996	void *end = p + msg->front.iov_len;
2997
2998	ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2999	next_mds = ceph_decode_32(&p);
3000	fwd_seq = ceph_decode_32(&p);
3001
3002	mutex_lock(&mdsc->mutex);
3003	req = lookup_get_request(mdsc, tid);
3004	if (!req) {
3005		dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3006		goto out;  /* dup reply? */
3007	}
3008
3009	if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3010		dout("forward tid %llu aborted, unregistering\n", tid);
3011		__unregister_request(mdsc, req);
3012	} else if (fwd_seq <= req->r_num_fwd) {
3013		dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3014		     tid, next_mds, req->r_num_fwd, fwd_seq);
3015	} else {
3016		/* resend. forward race not possible; mds would drop */
3017		dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3018		BUG_ON(req->r_err);
3019		BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3020		req->r_attempts = 0;
3021		req->r_num_fwd = fwd_seq;
3022		req->r_resend_mds = next_mds;
3023		put_request_session(req);
3024		__do_request(mdsc, req);
3025	}
3026	ceph_mdsc_put_request(req);
3027out:
3028	mutex_unlock(&mdsc->mutex);
3029	return;
3030
3031bad:
3032	pr_err("mdsc_handle_forward decode error err=%d\n", err);
3033}
3034
3035static int __decode_session_metadata(void **p, void *end,
3036				     bool *blacklisted)
3037{
3038	/* map<string,string> */
3039	u32 n;
3040	bool err_str;
3041	ceph_decode_32_safe(p, end, n, bad);
3042	while (n-- > 0) {
3043		u32 len;
3044		ceph_decode_32_safe(p, end, len, bad);
3045		ceph_decode_need(p, end, len, bad);
3046		err_str = !strncmp(*p, "error_string", len);
3047		*p += len;
3048		ceph_decode_32_safe(p, end, len, bad);
3049		ceph_decode_need(p, end, len, bad);
3050		if (err_str && strnstr(*p, "blacklisted", len))
3051			*blacklisted = true;
3052		*p += len;
3053	}
3054	return 0;
3055bad:
3056	return -1;
3057}
3058
3059/*
3060 * handle a mds session control message
3061 */
3062static void handle_session(struct ceph_mds_session *session,
3063			   struct ceph_msg *msg)
3064{
3065	struct ceph_mds_client *mdsc = session->s_mdsc;
3066	int mds = session->s_mds;
3067	int msg_version = le16_to_cpu(msg->hdr.version);
3068	void *p = msg->front.iov_base;
3069	void *end = p + msg->front.iov_len;
3070	struct ceph_mds_session_head *h;
3071	u32 op;
3072	u64 seq;
3073	unsigned long features = 0;
 
3074	int wake = 0;
3075	bool blacklisted = false;
3076
3077	/* decode */
3078	ceph_decode_need(&p, end, sizeof(*h), bad);
3079	h = p;
3080	p += sizeof(*h);
3081
3082	op = le32_to_cpu(h->op);
3083	seq = le64_to_cpu(h->seq);
3084
3085	if (msg_version >= 3) {
3086		u32 len;
3087		/* version >= 2, metadata */
3088		if (__decode_session_metadata(&p, end, &blacklisted) < 0)
3089			goto bad;
3090		/* version >= 3, feature bits */
3091		ceph_decode_32_safe(&p, end, len, bad);
3092		ceph_decode_need(&p, end, len, bad);
3093		memcpy(&features, p, min_t(size_t, len, sizeof(features)));
3094		p += len;
3095	}
3096
3097	mutex_lock(&mdsc->mutex);
3098	if (op == CEPH_SESSION_CLOSE) {
3099		get_session(session);
3100		__unregister_session(mdsc, session);
3101	}
3102	/* FIXME: this ttl calculation is generous */
3103	session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3104	mutex_unlock(&mdsc->mutex);
3105
3106	mutex_lock(&session->s_mutex);
3107
3108	dout("handle_session mds%d %s %p state %s seq %llu\n",
3109	     mds, ceph_session_op_name(op), session,
3110	     ceph_session_state_name(session->s_state), seq);
3111
3112	if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3113		session->s_state = CEPH_MDS_SESSION_OPEN;
3114		pr_info("mds%d came back\n", session->s_mds);
3115	}
3116
3117	switch (op) {
3118	case CEPH_SESSION_OPEN:
3119		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3120			pr_info("mds%d reconnect success\n", session->s_mds);
3121		session->s_state = CEPH_MDS_SESSION_OPEN;
3122		session->s_features = features;
3123		renewed_caps(mdsc, session, 0);
3124		wake = 1;
3125		if (mdsc->stopping)
3126			__close_session(mdsc, session);
3127		break;
3128
3129	case CEPH_SESSION_RENEWCAPS:
3130		if (session->s_renew_seq == seq)
3131			renewed_caps(mdsc, session, 1);
3132		break;
3133
3134	case CEPH_SESSION_CLOSE:
3135		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3136			pr_info("mds%d reconnect denied\n", session->s_mds);
3137		cleanup_session_requests(mdsc, session);
3138		remove_session_caps(session);
3139		wake = 2; /* for good measure */
3140		wake_up_all(&mdsc->session_close_wq);
3141		break;
3142
3143	case CEPH_SESSION_STALE:
3144		pr_info("mds%d caps went stale, renewing\n",
3145			session->s_mds);
3146		spin_lock(&session->s_gen_ttl_lock);
3147		session->s_cap_gen++;
3148		session->s_cap_ttl = jiffies - 1;
3149		spin_unlock(&session->s_gen_ttl_lock);
3150		send_renew_caps(mdsc, session);
3151		break;
3152
3153	case CEPH_SESSION_RECALL_STATE:
3154		ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3155		break;
3156
3157	case CEPH_SESSION_FLUSHMSG:
3158		send_flushmsg_ack(mdsc, session, seq);
3159		break;
3160
3161	case CEPH_SESSION_FORCE_RO:
3162		dout("force_session_readonly %p\n", session);
3163		spin_lock(&session->s_cap_lock);
3164		session->s_readonly = true;
3165		spin_unlock(&session->s_cap_lock);
3166		wake_up_session_caps(session, FORCE_RO);
3167		break;
3168
3169	case CEPH_SESSION_REJECT:
3170		WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3171		pr_info("mds%d rejected session\n", session->s_mds);
3172		session->s_state = CEPH_MDS_SESSION_REJECTED;
3173		cleanup_session_requests(mdsc, session);
3174		remove_session_caps(session);
3175		if (blacklisted)
3176			mdsc->fsc->blacklisted = true;
3177		wake = 2; /* for good measure */
3178		break;
3179
3180	default:
3181		pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3182		WARN_ON(1);
3183	}
3184
3185	mutex_unlock(&session->s_mutex);
3186	if (wake) {
3187		mutex_lock(&mdsc->mutex);
3188		__wake_requests(mdsc, &session->s_waiting);
3189		if (wake == 2)
3190			kick_requests(mdsc, mds);
3191		mutex_unlock(&mdsc->mutex);
3192	}
3193	if (op == CEPH_SESSION_CLOSE)
3194		ceph_put_mds_session(session);
3195	return;
3196
3197bad:
3198	pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3199	       (int)msg->front.iov_len);
3200	ceph_msg_dump(msg);
3201	return;
3202}
3203
3204
3205/*
3206 * called under session->mutex.
3207 */
3208static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3209				   struct ceph_mds_session *session)
3210{
3211	struct ceph_mds_request *req, *nreq;
3212	struct rb_node *p;
3213	int err;
3214
3215	dout("replay_unsafe_requests mds%d\n", session->s_mds);
3216
3217	mutex_lock(&mdsc->mutex);
3218	list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
3219		err = __prepare_send_request(mdsc, req, session->s_mds, true);
3220		if (!err) {
3221			ceph_msg_get(req->r_request);
3222			ceph_con_send(&session->s_con, req->r_request);
3223		}
3224	}
3225
3226	/*
3227	 * also re-send old requests when MDS enters reconnect stage. So that MDS
3228	 * can process completed request in clientreplay stage.
3229	 */
3230	p = rb_first(&mdsc->request_tree);
3231	while (p) {
3232		req = rb_entry(p, struct ceph_mds_request, r_node);
3233		p = rb_next(p);
3234		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3235			continue;
3236		if (req->r_attempts == 0)
3237			continue; /* only old requests */
3238		if (req->r_session &&
3239		    req->r_session->s_mds == session->s_mds) {
3240			err = __prepare_send_request(mdsc, req,
3241						     session->s_mds, true);
3242			if (!err) {
3243				ceph_msg_get(req->r_request);
3244				ceph_con_send(&session->s_con, req->r_request);
3245			}
3246		}
3247	}
3248	mutex_unlock(&mdsc->mutex);
3249}
3250
3251static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3252{
3253	struct ceph_msg *reply;
3254	struct ceph_pagelist *_pagelist;
3255	struct page *page;
3256	__le32 *addr;
3257	int err = -ENOMEM;
3258
3259	if (!recon_state->allow_multi)
3260		return -ENOSPC;
3261
3262	/* can't handle message that contains both caps and realm */
3263	BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3264
3265	/* pre-allocate new pagelist */
3266	_pagelist = ceph_pagelist_alloc(GFP_NOFS);
3267	if (!_pagelist)
3268		return -ENOMEM;
3269
3270	reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3271	if (!reply)
3272		goto fail_msg;
3273
3274	/* placeholder for nr_caps */
3275	err = ceph_pagelist_encode_32(_pagelist, 0);
3276	if (err < 0)
3277		goto fail;
3278
3279	if (recon_state->nr_caps) {
3280		/* currently encoding caps */
3281		err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3282		if (err)
3283			goto fail;
3284	} else {
3285		/* placeholder for nr_realms (currently encoding relams) */
3286		err = ceph_pagelist_encode_32(_pagelist, 0);
3287		if (err < 0)
3288			goto fail;
3289	}
3290
3291	err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3292	if (err)
3293		goto fail;
3294
3295	page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3296	addr = kmap_atomic(page);
3297	if (recon_state->nr_caps) {
3298		/* currently encoding caps */
3299		*addr = cpu_to_le32(recon_state->nr_caps);
3300	} else {
3301		/* currently encoding relams */
3302		*(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3303	}
3304	kunmap_atomic(addr);
3305
3306	reply->hdr.version = cpu_to_le16(5);
3307	reply->hdr.compat_version = cpu_to_le16(4);
3308
3309	reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3310	ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3311
3312	ceph_con_send(&recon_state->session->s_con, reply);
3313	ceph_pagelist_release(recon_state->pagelist);
3314
3315	recon_state->pagelist = _pagelist;
3316	recon_state->nr_caps = 0;
3317	recon_state->nr_realms = 0;
3318	recon_state->msg_version = 5;
3319	return 0;
3320fail:
3321	ceph_msg_put(reply);
3322fail_msg:
3323	ceph_pagelist_release(_pagelist);
3324	return err;
3325}
3326
3327/*
3328 * Encode information about a cap for a reconnect with the MDS.
3329 */
3330static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
3331			  void *arg)
3332{
3333	union {
3334		struct ceph_mds_cap_reconnect v2;
3335		struct ceph_mds_cap_reconnect_v1 v1;
3336	} rec;
3337	struct ceph_inode_info *ci = cap->ci;
3338	struct ceph_reconnect_state *recon_state = arg;
3339	struct ceph_pagelist *pagelist = recon_state->pagelist;
3340	int err;
 
 
3341	u64 snap_follows;
 
 
 
3342
3343	dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3344	     inode, ceph_vinop(inode), cap, cap->cap_id,
3345	     ceph_cap_string(cap->issued));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3346
3347	spin_lock(&ci->i_ceph_lock);
3348	cap->seq = 0;        /* reset cap seq */
3349	cap->issue_seq = 0;  /* and issue_seq */
3350	cap->mseq = 0;       /* and migrate_seq */
3351	cap->cap_gen = cap->session->s_cap_gen;
3352
3353	if (recon_state->msg_version >= 2) {
3354		rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3355		rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3356		rec.v2.issued = cpu_to_le32(cap->issued);
3357		rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3358		rec.v2.pathbase = 0;
3359		rec.v2.flock_len = (__force __le32)
3360			((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3361	} else {
3362		rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3363		rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3364		rec.v1.issued = cpu_to_le32(cap->issued);
3365		rec.v1.size = cpu_to_le64(inode->i_size);
3366		ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3367		ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3368		rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3369		rec.v1.pathbase = 0;
3370	}
3371
3372	if (list_empty(&ci->i_cap_snaps)) {
3373		snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3374	} else {
3375		struct ceph_cap_snap *capsnap =
3376			list_first_entry(&ci->i_cap_snaps,
3377					 struct ceph_cap_snap, ci_item);
3378		snap_follows = capsnap->follows;
3379	}
3380	spin_unlock(&ci->i_ceph_lock);
3381
3382	if (recon_state->msg_version >= 2) {
3383		int num_fcntl_locks, num_flock_locks;
3384		struct ceph_filelock *flocks = NULL;
3385		size_t struct_len, total_len = sizeof(u64);
3386		u8 struct_v = 0;
3387
3388encode_again:
3389		if (rec.v2.flock_len) {
3390			ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3391		} else {
3392			num_fcntl_locks = 0;
3393			num_flock_locks = 0;
3394		}
3395		if (num_fcntl_locks + num_flock_locks > 0) {
3396			flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3397					       sizeof(struct ceph_filelock),
3398					       GFP_NOFS);
3399			if (!flocks) {
3400				err = -ENOMEM;
3401				goto out_err;
3402			}
3403			err = ceph_encode_locks_to_buffer(inode, flocks,
3404							  num_fcntl_locks,
3405							  num_flock_locks);
3406			if (err) {
3407				kfree(flocks);
3408				flocks = NULL;
3409				if (err == -ENOSPC)
3410					goto encode_again;
3411				goto out_err;
3412			}
3413		} else {
3414			kfree(flocks);
3415			flocks = NULL;
 
 
3416		}
3417
3418		if (recon_state->msg_version >= 3) {
3419			/* version, compat_version and struct_len */
3420			total_len += 2 * sizeof(u8) + sizeof(u32);
3421			struct_v = 2;
3422		}
3423		/*
3424		 * number of encoded locks is stable, so copy to pagelist
3425		 */
3426		struct_len = 2 * sizeof(u32) +
3427			    (num_fcntl_locks + num_flock_locks) *
3428			    sizeof(struct ceph_filelock);
3429		rec.v2.flock_len = cpu_to_le32(struct_len);
3430
3431		struct_len += sizeof(u32) + sizeof(rec.v2);
 
3432
3433		if (struct_v >= 2)
3434			struct_len += sizeof(u64); /* snap_follows */
3435
3436		total_len += struct_len;
3437
3438		if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3439			err = send_reconnect_partial(recon_state);
3440			if (err)
3441				goto out_freeflocks;
3442			pagelist = recon_state->pagelist;
3443		}
3444
3445		err = ceph_pagelist_reserve(pagelist, total_len);
3446		if (err)
3447			goto out_freeflocks;
3448
3449		ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3450		if (recon_state->msg_version >= 3) {
3451			ceph_pagelist_encode_8(pagelist, struct_v);
3452			ceph_pagelist_encode_8(pagelist, 1);
3453			ceph_pagelist_encode_32(pagelist, struct_len);
3454		}
3455		ceph_pagelist_encode_string(pagelist, NULL, 0);
3456		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3457		ceph_locks_to_pagelist(flocks, pagelist,
3458				       num_fcntl_locks, num_flock_locks);
3459		if (struct_v >= 2)
3460			ceph_pagelist_encode_64(pagelist, snap_follows);
3461out_freeflocks:
3462		kfree(flocks);
3463	} else {
3464		u64 pathbase = 0;
3465		int pathlen = 0;
3466		char *path = NULL;
3467		struct dentry *dentry;
3468
3469		dentry = d_find_alias(inode);
3470		if (dentry) {
3471			path = ceph_mdsc_build_path(dentry,
3472						&pathlen, &pathbase, 0);
3473			dput(dentry);
3474			if (IS_ERR(path)) {
3475				err = PTR_ERR(path);
3476				goto out_err;
3477			}
3478			rec.v1.pathbase = cpu_to_le64(pathbase);
 
 
 
 
 
 
3479		}
3480
3481		err = ceph_pagelist_reserve(pagelist,
3482					    sizeof(u64) + sizeof(u32) +
3483					    pathlen + sizeof(rec.v1));
3484		if (err) {
3485			goto out_freepath;
 
3486		}
3487
3488		ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3489		ceph_pagelist_encode_string(pagelist, path, pathlen);
3490		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3491out_freepath:
3492		ceph_mdsc_free_path(path, pathlen);
3493	}
3494
3495out_err:
3496	if (err >= 0)
3497		recon_state->nr_caps++;
3498	return err;
3499}
3500
3501static int encode_snap_realms(struct ceph_mds_client *mdsc,
3502			      struct ceph_reconnect_state *recon_state)
3503{
3504	struct rb_node *p;
3505	struct ceph_pagelist *pagelist = recon_state->pagelist;
3506	int err = 0;
3507
3508	if (recon_state->msg_version >= 4) {
3509		err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3510		if (err < 0)
3511			goto fail;
3512	}
3513
3514	/*
3515	 * snaprealms.  we provide mds with the ino, seq (version), and
3516	 * parent for all of our realms.  If the mds has any newer info,
3517	 * it will tell us.
3518	 */
3519	for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3520		struct ceph_snap_realm *realm =
3521		       rb_entry(p, struct ceph_snap_realm, node);
3522		struct ceph_mds_snaprealm_reconnect sr_rec;
3523
3524		if (recon_state->msg_version >= 4) {
3525			size_t need = sizeof(u8) * 2 + sizeof(u32) +
3526				      sizeof(sr_rec);
3527
3528			if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3529				err = send_reconnect_partial(recon_state);
3530				if (err)
3531					goto fail;
3532				pagelist = recon_state->pagelist;
3533			}
3534
3535			err = ceph_pagelist_reserve(pagelist, need);
3536			if (err)
3537				goto fail;
3538
3539			ceph_pagelist_encode_8(pagelist, 1);
3540			ceph_pagelist_encode_8(pagelist, 1);
3541			ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3542		}
3543
3544		dout(" adding snap realm %llx seq %lld parent %llx\n",
3545		     realm->ino, realm->seq, realm->parent_ino);
3546		sr_rec.ino = cpu_to_le64(realm->ino);
3547		sr_rec.seq = cpu_to_le64(realm->seq);
3548		sr_rec.parent = cpu_to_le64(realm->parent_ino);
3549
3550		err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3551		if (err)
3552			goto fail;
3553
3554		recon_state->nr_realms++;
3555	}
3556fail:
3557	return err;
3558}
3559
3560
3561/*
3562 * If an MDS fails and recovers, clients need to reconnect in order to
3563 * reestablish shared state.  This includes all caps issued through
3564 * this session _and_ the snap_realm hierarchy.  Because it's not
3565 * clear which snap realms the mds cares about, we send everything we
3566 * know about.. that ensures we'll then get any new info the
3567 * recovering MDS might have.
3568 *
3569 * This is a relatively heavyweight operation, but it's rare.
3570 *
3571 * called with mdsc->mutex held.
3572 */
3573static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3574			       struct ceph_mds_session *session)
3575{
3576	struct ceph_msg *reply;
 
3577	int mds = session->s_mds;
3578	int err = -ENOMEM;
3579	struct ceph_reconnect_state recon_state = {
3580		.session = session,
3581	};
3582	LIST_HEAD(dispose);
3583
3584	pr_info("mds%d reconnect start\n", mds);
3585
3586	recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3587	if (!recon_state.pagelist)
3588		goto fail_nopagelist;
 
3589
3590	reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3591	if (!reply)
3592		goto fail_nomsg;
3593
3594	mutex_lock(&session->s_mutex);
3595	session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3596	session->s_seq = 0;
3597
3598	dout("session %p state %s\n", session,
3599	     ceph_session_state_name(session->s_state));
3600
3601	spin_lock(&session->s_gen_ttl_lock);
3602	session->s_cap_gen++;
3603	spin_unlock(&session->s_gen_ttl_lock);
3604
3605	spin_lock(&session->s_cap_lock);
3606	/* don't know if session is readonly */
3607	session->s_readonly = 0;
3608	/*
3609	 * notify __ceph_remove_cap() that we are composing cap reconnect.
3610	 * If a cap get released before being added to the cap reconnect,
3611	 * __ceph_remove_cap() should skip queuing cap release.
3612	 */
3613	session->s_cap_reconnect = 1;
3614	/* drop old cap expires; we're about to reestablish that state */
3615	detach_cap_releases(session, &dispose);
3616	spin_unlock(&session->s_cap_lock);
3617	dispose_cap_releases(mdsc, &dispose);
3618
3619	/* trim unused caps to reduce MDS's cache rejoin time */
3620	if (mdsc->fsc->sb->s_root)
3621		shrink_dcache_parent(mdsc->fsc->sb->s_root);
3622
3623	ceph_con_close(&session->s_con);
3624	ceph_con_open(&session->s_con,
3625		      CEPH_ENTITY_TYPE_MDS, mds,
3626		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3627
3628	/* replay unsafe requests */
3629	replay_unsafe_requests(mdsc, session);
3630
3631	ceph_early_kick_flushing_caps(mdsc, session);
3632
3633	down_read(&mdsc->snap_rwsem);
3634
3635	/* placeholder for nr_caps */
3636	err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
 
3637	if (err)
3638		goto fail;
3639
3640	if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3641		recon_state.msg_version = 3;
3642		recon_state.allow_multi = true;
3643	} else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3644		recon_state.msg_version = 3;
3645	} else {
3646		recon_state.msg_version = 2;
3647	}
3648	/* trsaverse this session's caps */
3649	err = ceph_iterate_session_caps(session, encode_caps_cb, &recon_state);
 
 
3650
3651	spin_lock(&session->s_cap_lock);
3652	session->s_cap_reconnect = 0;
3653	spin_unlock(&session->s_cap_lock);
3654
3655	if (err < 0)
3656		goto fail;
3657
3658	/* check if all realms can be encoded into current message */
3659	if (mdsc->num_snap_realms) {
3660		size_t total_len =
3661			recon_state.pagelist->length +
3662			mdsc->num_snap_realms *
3663			sizeof(struct ceph_mds_snaprealm_reconnect);
3664		if (recon_state.msg_version >= 4) {
3665			/* number of realms */
3666			total_len += sizeof(u32);
3667			/* version, compat_version and struct_len */
3668			total_len += mdsc->num_snap_realms *
3669				     (2 * sizeof(u8) + sizeof(u32));
3670		}
3671		if (total_len > RECONNECT_MAX_SIZE) {
3672			if (!recon_state.allow_multi) {
3673				err = -ENOSPC;
3674				goto fail;
3675			}
3676			if (recon_state.nr_caps) {
3677				err = send_reconnect_partial(&recon_state);
3678				if (err)
3679					goto fail;
3680			}
3681			recon_state.msg_version = 5;
3682		}
3683	}
3684
3685	err = encode_snap_realms(mdsc, &recon_state);
3686	if (err < 0)
3687		goto fail;
3688
3689	if (recon_state.msg_version >= 5) {
3690		err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
3691		if (err < 0)
 
 
 
 
3692			goto fail;
3693	}
3694
3695	if (recon_state.nr_caps || recon_state.nr_realms) {
3696		struct page *page =
3697			list_first_entry(&recon_state.pagelist->head,
3698					struct page, lru);
 
 
3699		__le32 *addr = kmap_atomic(page);
3700		if (recon_state.nr_caps) {
3701			WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
3702			*addr = cpu_to_le32(recon_state.nr_caps);
3703		} else if (recon_state.msg_version >= 4) {
3704			*(addr + 1) = cpu_to_le32(recon_state.nr_realms);
3705		}
3706		kunmap_atomic(addr);
3707	}
3708
3709	reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3710	if (recon_state.msg_version >= 4)
3711		reply->hdr.compat_version = cpu_to_le16(4);
3712
3713	reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
3714	ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
3715
3716	ceph_con_send(&session->s_con, reply);
3717
3718	mutex_unlock(&session->s_mutex);
3719
3720	mutex_lock(&mdsc->mutex);
3721	__wake_requests(mdsc, &session->s_waiting);
3722	mutex_unlock(&mdsc->mutex);
3723
3724	up_read(&mdsc->snap_rwsem);
3725	ceph_pagelist_release(recon_state.pagelist);
3726	return;
3727
3728fail:
3729	ceph_msg_put(reply);
3730	up_read(&mdsc->snap_rwsem);
3731	mutex_unlock(&session->s_mutex);
3732fail_nomsg:
3733	ceph_pagelist_release(recon_state.pagelist);
3734fail_nopagelist:
3735	pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3736	return;
3737}
3738
3739
3740/*
3741 * compare old and new mdsmaps, kicking requests
3742 * and closing out old connections as necessary
3743 *
3744 * called under mdsc->mutex.
3745 */
3746static void check_new_map(struct ceph_mds_client *mdsc,
3747			  struct ceph_mdsmap *newmap,
3748			  struct ceph_mdsmap *oldmap)
3749{
3750	int i;
3751	int oldstate, newstate;
3752	struct ceph_mds_session *s;
3753
3754	dout("check_new_map new %u old %u\n",
3755	     newmap->m_epoch, oldmap->m_epoch);
3756
3757	for (i = 0; i < oldmap->m_num_mds && i < mdsc->max_sessions; i++) {
3758		if (!mdsc->sessions[i])
3759			continue;
3760		s = mdsc->sessions[i];
3761		oldstate = ceph_mdsmap_get_state(oldmap, i);
3762		newstate = ceph_mdsmap_get_state(newmap, i);
3763
3764		dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3765		     i, ceph_mds_state_name(oldstate),
3766		     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3767		     ceph_mds_state_name(newstate),
3768		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3769		     ceph_session_state_name(s->s_state));
3770
3771		if (i >= newmap->m_num_mds) {
3772			/* force close session for stopped mds */
3773			get_session(s);
3774			__unregister_session(mdsc, s);
3775			__wake_requests(mdsc, &s->s_waiting);
3776			mutex_unlock(&mdsc->mutex);
3777
3778			mutex_lock(&s->s_mutex);
3779			cleanup_session_requests(mdsc, s);
3780			remove_session_caps(s);
3781			mutex_unlock(&s->s_mutex);
3782
3783			ceph_put_mds_session(s);
3784
3785			mutex_lock(&mdsc->mutex);
3786			kick_requests(mdsc, i);
3787			continue;
3788		}
3789
3790		if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
3791			   ceph_mdsmap_get_addr(newmap, i),
3792			   sizeof(struct ceph_entity_addr))) {
3793			/* just close it */
3794			mutex_unlock(&mdsc->mutex);
3795			mutex_lock(&s->s_mutex);
3796			mutex_lock(&mdsc->mutex);
3797			ceph_con_close(&s->s_con);
3798			mutex_unlock(&s->s_mutex);
3799			s->s_state = CEPH_MDS_SESSION_RESTARTING;
 
 
 
 
 
 
 
3800		} else if (oldstate == newstate) {
3801			continue;  /* nothing new with this mds */
3802		}
3803
3804		/*
3805		 * send reconnect?
3806		 */
3807		if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3808		    newstate >= CEPH_MDS_STATE_RECONNECT) {
3809			mutex_unlock(&mdsc->mutex);
3810			send_mds_reconnect(mdsc, s);
3811			mutex_lock(&mdsc->mutex);
3812		}
3813
3814		/*
3815		 * kick request on any mds that has gone active.
3816		 */
3817		if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3818		    newstate >= CEPH_MDS_STATE_ACTIVE) {
3819			if (oldstate != CEPH_MDS_STATE_CREATING &&
3820			    oldstate != CEPH_MDS_STATE_STARTING)
3821				pr_info("mds%d recovery completed\n", s->s_mds);
3822			kick_requests(mdsc, i);
3823			ceph_kick_flushing_caps(mdsc, s);
3824			wake_up_session_caps(s, RECONNECT);
3825		}
3826	}
3827
3828	for (i = 0; i < newmap->m_num_mds && i < mdsc->max_sessions; i++) {
3829		s = mdsc->sessions[i];
3830		if (!s)
3831			continue;
3832		if (!ceph_mdsmap_is_laggy(newmap, i))
3833			continue;
3834		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3835		    s->s_state == CEPH_MDS_SESSION_HUNG ||
3836		    s->s_state == CEPH_MDS_SESSION_CLOSING) {
3837			dout(" connecting to export targets of laggy mds%d\n",
3838			     i);
3839			__open_export_target_sessions(mdsc, s);
3840		}
3841	}
3842}
3843
3844
3845
3846/*
3847 * leases
3848 */
3849
3850/*
3851 * caller must hold session s_mutex, dentry->d_lock
3852 */
3853void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3854{
3855	struct ceph_dentry_info *di = ceph_dentry(dentry);
3856
3857	ceph_put_mds_session(di->lease_session);
3858	di->lease_session = NULL;
3859}
3860
3861static void handle_lease(struct ceph_mds_client *mdsc,
3862			 struct ceph_mds_session *session,
3863			 struct ceph_msg *msg)
3864{
3865	struct super_block *sb = mdsc->fsc->sb;
3866	struct inode *inode;
3867	struct dentry *parent, *dentry;
3868	struct ceph_dentry_info *di;
3869	int mds = session->s_mds;
3870	struct ceph_mds_lease *h = msg->front.iov_base;
3871	u32 seq;
3872	struct ceph_vino vino;
3873	struct qstr dname;
3874	int release = 0;
3875
3876	dout("handle_lease from mds%d\n", mds);
3877
3878	/* decode */
3879	if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3880		goto bad;
3881	vino.ino = le64_to_cpu(h->ino);
3882	vino.snap = CEPH_NOSNAP;
3883	seq = le32_to_cpu(h->seq);
3884	dname.len = get_unaligned_le32(h + 1);
3885	if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
 
3886		goto bad;
3887	dname.name = (void *)(h + 1) + sizeof(u32);
3888
3889	/* lookup inode */
3890	inode = ceph_find_inode(sb, vino);
3891	dout("handle_lease %s, ino %llx %p %.*s\n",
3892	     ceph_lease_op_name(h->action), vino.ino, inode,
3893	     dname.len, dname.name);
3894
3895	mutex_lock(&session->s_mutex);
3896	session->s_seq++;
3897
3898	if (!inode) {
3899		dout("handle_lease no inode %llx\n", vino.ino);
3900		goto release;
3901	}
3902
3903	/* dentry */
3904	parent = d_find_alias(inode);
3905	if (!parent) {
3906		dout("no parent dentry on inode %p\n", inode);
3907		WARN_ON(1);
3908		goto release;  /* hrm... */
3909	}
3910	dname.hash = full_name_hash(parent, dname.name, dname.len);
3911	dentry = d_lookup(parent, &dname);
3912	dput(parent);
3913	if (!dentry)
3914		goto release;
3915
3916	spin_lock(&dentry->d_lock);
3917	di = ceph_dentry(dentry);
3918	switch (h->action) {
3919	case CEPH_MDS_LEASE_REVOKE:
3920		if (di->lease_session == session) {
3921			if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3922				h->seq = cpu_to_le32(di->lease_seq);
3923			__ceph_mdsc_drop_dentry_lease(dentry);
3924		}
3925		release = 1;
3926		break;
3927
3928	case CEPH_MDS_LEASE_RENEW:
3929		if (di->lease_session == session &&
3930		    di->lease_gen == session->s_cap_gen &&
3931		    di->lease_renew_from &&
3932		    di->lease_renew_after == 0) {
3933			unsigned long duration =
3934				msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3935
3936			di->lease_seq = seq;
3937			di->time = di->lease_renew_from + duration;
3938			di->lease_renew_after = di->lease_renew_from +
3939				(duration >> 1);
3940			di->lease_renew_from = 0;
3941		}
3942		break;
3943	}
3944	spin_unlock(&dentry->d_lock);
3945	dput(dentry);
3946
3947	if (!release)
3948		goto out;
3949
3950release:
3951	/* let's just reuse the same message */
3952	h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3953	ceph_msg_get(msg);
3954	ceph_con_send(&session->s_con, msg);
3955
3956out:
 
3957	mutex_unlock(&session->s_mutex);
3958	/* avoid calling iput_final() in mds dispatch threads */
3959	ceph_async_iput(inode);
3960	return;
3961
3962bad:
3963	pr_err("corrupt lease message\n");
3964	ceph_msg_dump(msg);
3965}
3966
3967void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 
3968			      struct dentry *dentry, char action,
3969			      u32 seq)
3970{
3971	struct ceph_msg *msg;
3972	struct ceph_mds_lease *lease;
3973	struct inode *dir;
3974	int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
3975
3976	dout("lease_send_msg identry %p %s to mds%d\n",
3977	     dentry, ceph_lease_op_name(action), session->s_mds);
 
 
3978
3979	msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3980	if (!msg)
3981		return;
3982	lease = msg->front.iov_base;
3983	lease->action = action;
 
 
3984	lease->seq = cpu_to_le32(seq);
 
 
3985
3986	spin_lock(&dentry->d_lock);
3987	dir = d_inode(dentry->d_parent);
3988	lease->ino = cpu_to_le64(ceph_ino(dir));
3989	lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
3990
3991	put_unaligned_le32(dentry->d_name.len, lease + 1);
3992	memcpy((void *)(lease + 1) + 4,
3993	       dentry->d_name.name, dentry->d_name.len);
3994	spin_unlock(&dentry->d_lock);
3995	/*
3996	 * if this is a preemptive lease RELEASE, no need to
3997	 * flush request stream, since the actual request will
3998	 * soon follow.
3999	 */
4000	msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4001
4002	ceph_con_send(&session->s_con, msg);
4003}
4004
4005/*
4006 * lock unlock sessions, to wait ongoing session activities
4007 */
4008static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4009{
4010	int i;
4011
 
4012	mutex_lock(&mdsc->mutex);
4013	for (i = 0; i < mdsc->max_sessions; i++) {
4014		struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4015		if (!s)
4016			continue;
4017		mutex_unlock(&mdsc->mutex);
4018		mutex_lock(&s->s_mutex);
4019		mutex_unlock(&s->s_mutex);
4020		ceph_put_mds_session(s);
4021		mutex_lock(&mdsc->mutex);
4022	}
4023	mutex_unlock(&mdsc->mutex);
4024}
4025
4026static void maybe_recover_session(struct ceph_mds_client *mdsc)
4027{
4028	struct ceph_fs_client *fsc = mdsc->fsc;
4029
4030	if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4031		return;
4032
4033	if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4034		return;
4035
4036	if (!READ_ONCE(fsc->blacklisted))
4037		return;
4038
4039	if (fsc->last_auto_reconnect &&
4040	    time_before(jiffies, fsc->last_auto_reconnect + HZ * 60 * 30))
4041		return;
4042
4043	pr_info("auto reconnect after blacklisted\n");
4044	fsc->last_auto_reconnect = jiffies;
4045	ceph_force_reconnect(fsc->sb);
4046}
4047
4048/*
4049 * delayed work -- periodically trim expired leases, renew caps with mds
4050 */
4051static void schedule_delayed(struct ceph_mds_client *mdsc)
4052{
4053	int delay = 5;
4054	unsigned hz = round_jiffies_relative(HZ * delay);
4055	schedule_delayed_work(&mdsc->delayed_work, hz);
4056}
4057
4058static void delayed_work(struct work_struct *work)
4059{
4060	int i;
4061	struct ceph_mds_client *mdsc =
4062		container_of(work, struct ceph_mds_client, delayed_work.work);
4063	int renew_interval;
4064	int renew_caps;
4065
4066	dout("mdsc delayed_work\n");
 
4067
4068	mutex_lock(&mdsc->mutex);
4069	renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4070	renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4071				   mdsc->last_renew_caps);
4072	if (renew_caps)
4073		mdsc->last_renew_caps = jiffies;
4074
4075	for (i = 0; i < mdsc->max_sessions; i++) {
4076		struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4077		if (!s)
4078			continue;
4079		if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4080			dout("resending session close request for mds%d\n",
4081			     s->s_mds);
4082			request_close_session(mdsc, s);
4083			ceph_put_mds_session(s);
4084			continue;
4085		}
4086		if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4087			if (s->s_state == CEPH_MDS_SESSION_OPEN) {
4088				s->s_state = CEPH_MDS_SESSION_HUNG;
4089				pr_info("mds%d hung\n", s->s_mds);
4090			}
4091		}
4092		if (s->s_state == CEPH_MDS_SESSION_NEW ||
4093		    s->s_state == CEPH_MDS_SESSION_RESTARTING ||
4094		    s->s_state == CEPH_MDS_SESSION_REJECTED) {
4095			/* this mds is failed or recovering, just wait */
4096			ceph_put_mds_session(s);
4097			continue;
4098		}
4099		mutex_unlock(&mdsc->mutex);
4100
4101		mutex_lock(&s->s_mutex);
4102		if (renew_caps)
4103			send_renew_caps(mdsc, s);
4104		else
4105			ceph_con_keepalive(&s->s_con);
4106		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4107		    s->s_state == CEPH_MDS_SESSION_HUNG)
4108			ceph_send_cap_releases(mdsc, s);
4109		mutex_unlock(&s->s_mutex);
4110		ceph_put_mds_session(s);
4111
4112		mutex_lock(&mdsc->mutex);
4113	}
4114	mutex_unlock(&mdsc->mutex);
4115
4116	ceph_check_delayed_caps(mdsc);
4117
4118	ceph_queue_cap_reclaim_work(mdsc);
4119
4120	ceph_trim_snapid_map(mdsc);
4121
4122	maybe_recover_session(mdsc);
4123
4124	schedule_delayed(mdsc);
4125}
4126
4127int ceph_mdsc_init(struct ceph_fs_client *fsc)
4128
4129{
4130	struct ceph_mds_client *mdsc;
4131
4132	mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4133	if (!mdsc)
4134		return -ENOMEM;
4135	mdsc->fsc = fsc;
 
4136	mutex_init(&mdsc->mutex);
4137	mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4138	if (!mdsc->mdsmap) {
4139		kfree(mdsc);
4140		return -ENOMEM;
4141	}
4142
4143	fsc->mdsc = mdsc;
4144	init_completion(&mdsc->safe_umount_waiters);
4145	init_waitqueue_head(&mdsc->session_close_wq);
4146	INIT_LIST_HEAD(&mdsc->waiting_for_map);
4147	mdsc->sessions = NULL;
4148	atomic_set(&mdsc->num_sessions, 0);
4149	mdsc->max_sessions = 0;
4150	mdsc->stopping = 0;
4151	atomic64_set(&mdsc->quotarealms_count, 0);
4152	mdsc->quotarealms_inodes = RB_ROOT;
4153	mutex_init(&mdsc->quotarealms_inodes_mutex);
4154	mdsc->last_snap_seq = 0;
4155	init_rwsem(&mdsc->snap_rwsem);
4156	mdsc->snap_realms = RB_ROOT;
4157	INIT_LIST_HEAD(&mdsc->snap_empty);
4158	mdsc->num_snap_realms = 0;
4159	spin_lock_init(&mdsc->snap_empty_lock);
4160	mdsc->last_tid = 0;
4161	mdsc->oldest_tid = 0;
4162	mdsc->request_tree = RB_ROOT;
4163	INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4164	mdsc->last_renew_caps = jiffies;
4165	INIT_LIST_HEAD(&mdsc->cap_delay_list);
4166	spin_lock_init(&mdsc->cap_delay_lock);
4167	INIT_LIST_HEAD(&mdsc->snap_flush_list);
4168	spin_lock_init(&mdsc->snap_flush_lock);
4169	mdsc->last_cap_flush_tid = 1;
4170	INIT_LIST_HEAD(&mdsc->cap_flush_list);
4171	INIT_LIST_HEAD(&mdsc->cap_dirty);
4172	INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4173	mdsc->num_cap_flushing = 0;
4174	spin_lock_init(&mdsc->cap_dirty_lock);
4175	init_waitqueue_head(&mdsc->cap_flushing_wq);
4176	INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4177	atomic_set(&mdsc->cap_reclaim_pending, 0);
4178
4179	spin_lock_init(&mdsc->dentry_list_lock);
4180	INIT_LIST_HEAD(&mdsc->dentry_leases);
4181	INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4182
4183	ceph_caps_init(mdsc);
4184	ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4185
4186	spin_lock_init(&mdsc->snapid_map_lock);
4187	mdsc->snapid_map_tree = RB_ROOT;
4188	INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4189
4190	init_rwsem(&mdsc->pool_perm_rwsem);
4191	mdsc->pool_perm_tree = RB_ROOT;
4192
4193	strscpy(mdsc->nodename, utsname()->nodename,
4194		sizeof(mdsc->nodename));
4195	return 0;
4196}
4197
4198/*
4199 * Wait for safe replies on open mds requests.  If we time out, drop
4200 * all requests from the tree to avoid dangling dentry refs.
4201 */
4202static void wait_requests(struct ceph_mds_client *mdsc)
4203{
4204	struct ceph_options *opts = mdsc->fsc->client->options;
4205	struct ceph_mds_request *req;
4206
4207	mutex_lock(&mdsc->mutex);
4208	if (__get_oldest_req(mdsc)) {
4209		mutex_unlock(&mdsc->mutex);
4210
4211		dout("wait_requests waiting for requests\n");
4212		wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4213				    ceph_timeout_jiffies(opts->mount_timeout));
4214
4215		/* tear down remaining requests */
4216		mutex_lock(&mdsc->mutex);
4217		while ((req = __get_oldest_req(mdsc))) {
4218			dout("wait_requests timed out on tid %llu\n",
4219			     req->r_tid);
4220			list_del_init(&req->r_wait);
4221			__unregister_request(mdsc, req);
4222		}
4223	}
4224	mutex_unlock(&mdsc->mutex);
4225	dout("wait_requests done\n");
4226}
4227
4228/*
4229 * called before mount is ro, and before dentries are torn down.
4230 * (hmm, does this still race with new lookups?)
4231 */
4232void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4233{
4234	dout("pre_umount\n");
4235	mdsc->stopping = 1;
4236
4237	lock_unlock_sessions(mdsc);
4238	ceph_flush_dirty_caps(mdsc);
4239	wait_requests(mdsc);
4240
4241	/*
4242	 * wait for reply handlers to drop their request refs and
4243	 * their inode/dcache refs
4244	 */
4245	ceph_msgr_flush();
4246
4247	ceph_cleanup_quotarealms_inodes(mdsc);
4248}
4249
4250/*
4251 * wait for all write mds requests to flush.
4252 */
4253static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4254{
4255	struct ceph_mds_request *req = NULL, *nextreq;
4256	struct rb_node *n;
4257
4258	mutex_lock(&mdsc->mutex);
4259	dout("wait_unsafe_requests want %lld\n", want_tid);
4260restart:
4261	req = __get_oldest_req(mdsc);
4262	while (req && req->r_tid <= want_tid) {
4263		/* find next request */
4264		n = rb_next(&req->r_node);
4265		if (n)
4266			nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4267		else
4268			nextreq = NULL;
4269		if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4270		    (req->r_op & CEPH_MDS_OP_WRITE)) {
4271			/* write op */
4272			ceph_mdsc_get_request(req);
4273			if (nextreq)
4274				ceph_mdsc_get_request(nextreq);
4275			mutex_unlock(&mdsc->mutex);
4276			dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4277			     req->r_tid, want_tid);
4278			wait_for_completion(&req->r_safe_completion);
4279			mutex_lock(&mdsc->mutex);
4280			ceph_mdsc_put_request(req);
4281			if (!nextreq)
4282				break;  /* next dne before, so we're done! */
4283			if (RB_EMPTY_NODE(&nextreq->r_node)) {
4284				/* next request was removed from tree */
4285				ceph_mdsc_put_request(nextreq);
4286				goto restart;
4287			}
4288			ceph_mdsc_put_request(nextreq);  /* won't go away */
4289		}
4290		req = nextreq;
4291	}
4292	mutex_unlock(&mdsc->mutex);
4293	dout("wait_unsafe_requests done\n");
4294}
4295
4296void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4297{
4298	u64 want_tid, want_flush;
4299
4300	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4301		return;
4302
4303	dout("sync\n");
4304	mutex_lock(&mdsc->mutex);
4305	want_tid = mdsc->last_tid;
4306	mutex_unlock(&mdsc->mutex);
4307
4308	ceph_flush_dirty_caps(mdsc);
4309	spin_lock(&mdsc->cap_dirty_lock);
4310	want_flush = mdsc->last_cap_flush_tid;
4311	if (!list_empty(&mdsc->cap_flush_list)) {
4312		struct ceph_cap_flush *cf =
4313			list_last_entry(&mdsc->cap_flush_list,
4314					struct ceph_cap_flush, g_list);
4315		cf->wake = true;
4316	}
4317	spin_unlock(&mdsc->cap_dirty_lock);
4318
4319	dout("sync want tid %lld flush_seq %lld\n",
4320	     want_tid, want_flush);
4321
4322	wait_unsafe_requests(mdsc, want_tid);
4323	wait_caps_flush(mdsc, want_flush);
4324}
4325
4326/*
4327 * true if all sessions are closed, or we force unmount
4328 */
4329static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4330{
4331	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4332		return true;
4333	return atomic_read(&mdsc->num_sessions) <= skipped;
4334}
4335
4336/*
4337 * called after sb is ro.
4338 */
4339void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4340{
4341	struct ceph_options *opts = mdsc->fsc->client->options;
4342	struct ceph_mds_session *session;
4343	int i;
4344	int skipped = 0;
4345
4346	dout("close_sessions\n");
4347
4348	/* close sessions */
4349	mutex_lock(&mdsc->mutex);
4350	for (i = 0; i < mdsc->max_sessions; i++) {
4351		session = __ceph_lookup_mds_session(mdsc, i);
4352		if (!session)
4353			continue;
4354		mutex_unlock(&mdsc->mutex);
4355		mutex_lock(&session->s_mutex);
4356		if (__close_session(mdsc, session) <= 0)
4357			skipped++;
4358		mutex_unlock(&session->s_mutex);
4359		ceph_put_mds_session(session);
4360		mutex_lock(&mdsc->mutex);
4361	}
4362	mutex_unlock(&mdsc->mutex);
4363
4364	dout("waiting for sessions to close\n");
4365	wait_event_timeout(mdsc->session_close_wq,
4366			   done_closing_sessions(mdsc, skipped),
4367			   ceph_timeout_jiffies(opts->mount_timeout));
4368
4369	/* tear down remaining sessions */
4370	mutex_lock(&mdsc->mutex);
4371	for (i = 0; i < mdsc->max_sessions; i++) {
4372		if (mdsc->sessions[i]) {
4373			session = get_session(mdsc->sessions[i]);
4374			__unregister_session(mdsc, session);
4375			mutex_unlock(&mdsc->mutex);
4376			mutex_lock(&session->s_mutex);
4377			remove_session_caps(session);
4378			mutex_unlock(&session->s_mutex);
4379			ceph_put_mds_session(session);
4380			mutex_lock(&mdsc->mutex);
4381		}
4382	}
4383	WARN_ON(!list_empty(&mdsc->cap_delay_list));
4384	mutex_unlock(&mdsc->mutex);
4385
4386	ceph_cleanup_snapid_map(mdsc);
4387	ceph_cleanup_empty_realms(mdsc);
4388
4389	cancel_work_sync(&mdsc->cap_reclaim_work);
4390	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4391
4392	dout("stopped\n");
4393}
4394
4395void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4396{
4397	struct ceph_mds_session *session;
4398	int mds;
4399
4400	dout("force umount\n");
4401
4402	mutex_lock(&mdsc->mutex);
4403	for (mds = 0; mds < mdsc->max_sessions; mds++) {
4404		session = __ceph_lookup_mds_session(mdsc, mds);
4405		if (!session)
4406			continue;
4407
4408		if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4409			__unregister_session(mdsc, session);
4410		__wake_requests(mdsc, &session->s_waiting);
4411		mutex_unlock(&mdsc->mutex);
4412
4413		mutex_lock(&session->s_mutex);
4414		__close_session(mdsc, session);
4415		if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4416			cleanup_session_requests(mdsc, session);
4417			remove_session_caps(session);
4418		}
4419		mutex_unlock(&session->s_mutex);
4420		ceph_put_mds_session(session);
4421
4422		mutex_lock(&mdsc->mutex);
4423		kick_requests(mdsc, mds);
4424	}
4425	__wake_requests(mdsc, &mdsc->waiting_for_map);
4426	mutex_unlock(&mdsc->mutex);
4427}
4428
4429static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4430{
4431	dout("stop\n");
4432	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4433	if (mdsc->mdsmap)
4434		ceph_mdsmap_destroy(mdsc->mdsmap);
4435	kfree(mdsc->sessions);
4436	ceph_caps_finalize(mdsc);
4437	ceph_pool_perm_destroy(mdsc);
4438}
4439
4440void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4441{
4442	struct ceph_mds_client *mdsc = fsc->mdsc;
4443	dout("mdsc_destroy %p\n", mdsc);
4444
4445	if (!mdsc)
4446		return;
4447
4448	/* flush out any connection work with references to us */
4449	ceph_msgr_flush();
4450
4451	ceph_mdsc_stop(mdsc);
4452
4453	fsc->mdsc = NULL;
4454	kfree(mdsc);
4455	dout("mdsc_destroy %p done\n", mdsc);
4456}
4457
4458void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4459{
4460	struct ceph_fs_client *fsc = mdsc->fsc;
4461	const char *mds_namespace = fsc->mount_options->mds_namespace;
4462	void *p = msg->front.iov_base;
4463	void *end = p + msg->front.iov_len;
4464	u32 epoch;
4465	u32 map_len;
4466	u32 num_fs;
4467	u32 mount_fscid = (u32)-1;
4468	u8 struct_v, struct_cv;
4469	int err = -EINVAL;
4470
4471	ceph_decode_need(&p, end, sizeof(u32), bad);
4472	epoch = ceph_decode_32(&p);
4473
4474	dout("handle_fsmap epoch %u\n", epoch);
4475
4476	ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4477	struct_v = ceph_decode_8(&p);
4478	struct_cv = ceph_decode_8(&p);
4479	map_len = ceph_decode_32(&p);
4480
4481	ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4482	p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4483
4484	num_fs = ceph_decode_32(&p);
4485	while (num_fs-- > 0) {
4486		void *info_p, *info_end;
4487		u32 info_len;
4488		u8 info_v, info_cv;
4489		u32 fscid, namelen;
4490
4491		ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4492		info_v = ceph_decode_8(&p);
4493		info_cv = ceph_decode_8(&p);
4494		info_len = ceph_decode_32(&p);
4495		ceph_decode_need(&p, end, info_len, bad);
4496		info_p = p;
4497		info_end = p + info_len;
4498		p = info_end;
4499
4500		ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4501		fscid = ceph_decode_32(&info_p);
4502		namelen = ceph_decode_32(&info_p);
4503		ceph_decode_need(&info_p, info_end, namelen, bad);
4504
4505		if (mds_namespace &&
4506		    strlen(mds_namespace) == namelen &&
4507		    !strncmp(mds_namespace, (char *)info_p, namelen)) {
4508			mount_fscid = fscid;
4509			break;
4510		}
4511	}
4512
4513	ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4514	if (mount_fscid != (u32)-1) {
4515		fsc->client->monc.fs_cluster_id = mount_fscid;
4516		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4517				   0, true);
4518		ceph_monc_renew_subs(&fsc->client->monc);
4519	} else {
4520		err = -ENOENT;
4521		goto err_out;
4522	}
4523	return;
4524
4525bad:
4526	pr_err("error decoding fsmap\n");
4527err_out:
4528	mutex_lock(&mdsc->mutex);
4529	mdsc->mdsmap_err = err;
4530	__wake_requests(mdsc, &mdsc->waiting_for_map);
4531	mutex_unlock(&mdsc->mutex);
 
4532}
4533
4534/*
4535 * handle mds map update.
4536 */
4537void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4538{
4539	u32 epoch;
4540	u32 maplen;
4541	void *p = msg->front.iov_base;
4542	void *end = p + msg->front.iov_len;
4543	struct ceph_mdsmap *newmap, *oldmap;
4544	struct ceph_fsid fsid;
4545	int err = -EINVAL;
4546
4547	ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4548	ceph_decode_copy(&p, &fsid, sizeof(fsid));
4549	if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4550		return;
4551	epoch = ceph_decode_32(&p);
4552	maplen = ceph_decode_32(&p);
4553	dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4554
4555	/* do we need it? */
4556	mutex_lock(&mdsc->mutex);
4557	if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4558		dout("handle_map epoch %u <= our %u\n",
4559		     epoch, mdsc->mdsmap->m_epoch);
4560		mutex_unlock(&mdsc->mutex);
4561		return;
4562	}
4563
4564	newmap = ceph_mdsmap_decode(&p, end);
4565	if (IS_ERR(newmap)) {
4566		err = PTR_ERR(newmap);
4567		goto bad_unlock;
4568	}
4569
4570	/* swap into place */
4571	if (mdsc->mdsmap) {
4572		oldmap = mdsc->mdsmap;
4573		mdsc->mdsmap = newmap;
4574		check_new_map(mdsc, newmap, oldmap);
4575		ceph_mdsmap_destroy(oldmap);
4576	} else {
4577		mdsc->mdsmap = newmap;  /* first mds map */
4578	}
4579	mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4580					MAX_LFS_FILESIZE);
4581
4582	__wake_requests(mdsc, &mdsc->waiting_for_map);
4583	ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4584			  mdsc->mdsmap->m_epoch);
4585
4586	mutex_unlock(&mdsc->mutex);
4587	schedule_delayed(mdsc);
4588	return;
4589
4590bad_unlock:
4591	mutex_unlock(&mdsc->mutex);
4592bad:
4593	pr_err("error decoding mdsmap %d\n", err);
4594	return;
4595}
4596
4597static struct ceph_connection *con_get(struct ceph_connection *con)
4598{
4599	struct ceph_mds_session *s = con->private;
4600
4601	if (get_session(s)) {
4602		dout("mdsc con_get %p ok (%d)\n", s, refcount_read(&s->s_ref));
4603		return con;
4604	}
4605	dout("mdsc con_get %p FAIL\n", s);
4606	return NULL;
4607}
4608
4609static void con_put(struct ceph_connection *con)
4610{
4611	struct ceph_mds_session *s = con->private;
4612
4613	dout("mdsc con_put %p (%d)\n", s, refcount_read(&s->s_ref) - 1);
4614	ceph_put_mds_session(s);
4615}
4616
4617/*
4618 * if the client is unresponsive for long enough, the mds will kill
4619 * the session entirely.
4620 */
4621static void peer_reset(struct ceph_connection *con)
4622{
4623	struct ceph_mds_session *s = con->private;
4624	struct ceph_mds_client *mdsc = s->s_mdsc;
4625
4626	pr_warn("mds%d closed our session\n", s->s_mds);
4627	send_mds_reconnect(mdsc, s);
4628}
4629
4630static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
4631{
4632	struct ceph_mds_session *s = con->private;
4633	struct ceph_mds_client *mdsc = s->s_mdsc;
4634	int type = le16_to_cpu(msg->hdr.type);
4635
4636	mutex_lock(&mdsc->mutex);
4637	if (__verify_registered_session(mdsc, s) < 0) {
4638		mutex_unlock(&mdsc->mutex);
4639		goto out;
4640	}
4641	mutex_unlock(&mdsc->mutex);
4642
4643	switch (type) {
4644	case CEPH_MSG_MDS_MAP:
4645		ceph_mdsc_handle_mdsmap(mdsc, msg);
4646		break;
4647	case CEPH_MSG_FS_MAP_USER:
4648		ceph_mdsc_handle_fsmap(mdsc, msg);
4649		break;
4650	case CEPH_MSG_CLIENT_SESSION:
4651		handle_session(s, msg);
4652		break;
4653	case CEPH_MSG_CLIENT_REPLY:
4654		handle_reply(s, msg);
4655		break;
4656	case CEPH_MSG_CLIENT_REQUEST_FORWARD:
4657		handle_forward(mdsc, s, msg);
4658		break;
4659	case CEPH_MSG_CLIENT_CAPS:
4660		ceph_handle_caps(s, msg);
4661		break;
4662	case CEPH_MSG_CLIENT_SNAP:
4663		ceph_handle_snap(mdsc, s, msg);
4664		break;
4665	case CEPH_MSG_CLIENT_LEASE:
4666		handle_lease(mdsc, s, msg);
4667		break;
4668	case CEPH_MSG_CLIENT_QUOTA:
4669		ceph_handle_quota(mdsc, s, msg);
4670		break;
4671
4672	default:
4673		pr_err("received unknown message type %d %s\n", type,
4674		       ceph_msg_type_name(type));
4675	}
4676out:
4677	ceph_msg_put(msg);
4678}
4679
4680/*
4681 * authentication
4682 */
4683
4684/*
4685 * Note: returned pointer is the address of a structure that's
4686 * managed separately.  Caller must *not* attempt to free it.
4687 */
4688static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
4689					int *proto, int force_new)
4690{
4691	struct ceph_mds_session *s = con->private;
4692	struct ceph_mds_client *mdsc = s->s_mdsc;
4693	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4694	struct ceph_auth_handshake *auth = &s->s_auth;
4695
4696	if (force_new && auth->authorizer) {
4697		ceph_auth_destroy_authorizer(auth->authorizer);
4698		auth->authorizer = NULL;
4699	}
4700	if (!auth->authorizer) {
4701		int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4702						      auth);
4703		if (ret)
4704			return ERR_PTR(ret);
4705	} else {
4706		int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4707						      auth);
4708		if (ret)
4709			return ERR_PTR(ret);
4710	}
4711	*proto = ac->protocol;
4712
4713	return auth;
4714}
4715
4716static int add_authorizer_challenge(struct ceph_connection *con,
4717				    void *challenge_buf, int challenge_buf_len)
4718{
4719	struct ceph_mds_session *s = con->private;
4720	struct ceph_mds_client *mdsc = s->s_mdsc;
4721	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4722
4723	return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
4724					    challenge_buf, challenge_buf_len);
4725}
4726
4727static int verify_authorizer_reply(struct ceph_connection *con)
4728{
4729	struct ceph_mds_session *s = con->private;
4730	struct ceph_mds_client *mdsc = s->s_mdsc;
4731	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4732
4733	return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
4734}
4735
4736static int invalidate_authorizer(struct ceph_connection *con)
4737{
4738	struct ceph_mds_session *s = con->private;
4739	struct ceph_mds_client *mdsc = s->s_mdsc;
4740	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4741
4742	ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
4743
4744	return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
4745}
4746
4747static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
4748				struct ceph_msg_header *hdr, int *skip)
4749{
4750	struct ceph_msg *msg;
4751	int type = (int) le16_to_cpu(hdr->type);
4752	int front_len = (int) le32_to_cpu(hdr->front_len);
4753
4754	if (con->in_msg)
4755		return con->in_msg;
4756
4757	*skip = 0;
4758	msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
4759	if (!msg) {
4760		pr_err("unable to allocate msg type %d len %d\n",
4761		       type, front_len);
4762		return NULL;
4763	}
4764
4765	return msg;
4766}
4767
4768static int mds_sign_message(struct ceph_msg *msg)
4769{
4770       struct ceph_mds_session *s = msg->con->private;
4771       struct ceph_auth_handshake *auth = &s->s_auth;
4772
4773       return ceph_auth_sign_message(auth, msg);
4774}
4775
4776static int mds_check_message_signature(struct ceph_msg *msg)
4777{
4778       struct ceph_mds_session *s = msg->con->private;
4779       struct ceph_auth_handshake *auth = &s->s_auth;
4780
4781       return ceph_auth_check_message_signature(auth, msg);
4782}
4783
4784static const struct ceph_connection_operations mds_con_ops = {
4785	.get = con_get,
4786	.put = con_put,
4787	.dispatch = dispatch,
4788	.get_authorizer = get_authorizer,
4789	.add_authorizer_challenge = add_authorizer_challenge,
4790	.verify_authorizer_reply = verify_authorizer_reply,
4791	.invalidate_authorizer = invalidate_authorizer,
4792	.peer_reset = peer_reset,
4793	.alloc_msg = mds_alloc_msg,
4794	.sign_message = mds_sign_message,
4795	.check_message_signature = mds_check_message_signature,
4796};
4797
4798/* eof */
v4.10.11
 
   1#include <linux/ceph/ceph_debug.h>
   2
   3#include <linux/fs.h>
   4#include <linux/wait.h>
   5#include <linux/slab.h>
   6#include <linux/gfp.h>
   7#include <linux/sched.h>
   8#include <linux/debugfs.h>
   9#include <linux/seq_file.h>
  10#include <linux/utsname.h>
  11#include <linux/ratelimit.h>
  12
  13#include "super.h"
  14#include "mds_client.h"
  15
  16#include <linux/ceph/ceph_features.h>
  17#include <linux/ceph/messenger.h>
  18#include <linux/ceph/decode.h>
  19#include <linux/ceph/pagelist.h>
  20#include <linux/ceph/auth.h>
  21#include <linux/ceph/debugfs.h>
  22
 
 
  23/*
  24 * A cluster of MDS (metadata server) daemons is responsible for
  25 * managing the file system namespace (the directory hierarchy and
  26 * inodes) and for coordinating shared access to storage.  Metadata is
  27 * partitioning hierarchically across a number of servers, and that
  28 * partition varies over time as the cluster adjusts the distribution
  29 * in order to balance load.
  30 *
  31 * The MDS client is primarily responsible to managing synchronous
  32 * metadata requests for operations like open, unlink, and so forth.
  33 * If there is a MDS failure, we find out about it when we (possibly
  34 * request and) receive a new MDS map, and can resubmit affected
  35 * requests.
  36 *
  37 * For the most part, though, we take advantage of a lossless
  38 * communications channel to the MDS, and do not need to worry about
  39 * timing out or resubmitting requests.
  40 *
  41 * We maintain a stateful "session" with each MDS we interact with.
  42 * Within each session, we sent periodic heartbeat messages to ensure
  43 * any capabilities or leases we have been issues remain valid.  If
  44 * the session times out and goes stale, our leases and capabilities
  45 * are no longer valid.
  46 */
  47
  48struct ceph_reconnect_state {
  49	int nr_caps;
 
  50	struct ceph_pagelist *pagelist;
  51	unsigned msg_version;
 
  52};
  53
  54static void __wake_requests(struct ceph_mds_client *mdsc,
  55			    struct list_head *head);
 
 
  56
  57static const struct ceph_connection_operations mds_con_ops;
  58
  59
  60/*
  61 * mds reply parsing
  62 */
  63
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  64/*
  65 * parse individual inode info
  66 */
  67static int parse_reply_info_in(void **p, void *end,
  68			       struct ceph_mds_reply_info_in *info,
  69			       u64 features)
  70{
  71	int err = -EIO;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  72
 
  73	info->in = *p;
  74	*p += sizeof(struct ceph_mds_reply_inode) +
  75		sizeof(*info->in->fragtree.splits) *
  76		le32_to_cpu(info->in->fragtree.nsplits);
  77
  78	ceph_decode_32_safe(p, end, info->symlink_len, bad);
  79	ceph_decode_need(p, end, info->symlink_len, bad);
  80	info->symlink = *p;
  81	*p += info->symlink_len;
  82
  83	if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  84		ceph_decode_copy_safe(p, end, &info->dir_layout,
  85				      sizeof(info->dir_layout), bad);
  86	else
  87		memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  88
  89	ceph_decode_32_safe(p, end, info->xattr_len, bad);
  90	ceph_decode_need(p, end, info->xattr_len, bad);
  91	info->xattr_data = *p;
  92	*p += info->xattr_len;
  93
  94	if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 
  95		ceph_decode_64_safe(p, end, info->inline_version, bad);
  96		ceph_decode_32_safe(p, end, info->inline_len, bad);
  97		ceph_decode_need(p, end, info->inline_len, bad);
  98		info->inline_data = *p;
  99		*p += info->inline_len;
 100	} else
 101		info->inline_version = CEPH_INLINE_NONE;
 102
 103	info->pool_ns_len = 0;
 104	info->pool_ns_data = NULL;
 105	if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 106		ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 107		if (info->pool_ns_len > 0) {
 108			ceph_decode_need(p, end, info->pool_ns_len, bad);
 109			info->pool_ns_data = *p;
 110			*p += info->pool_ns_len;
 111		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 112	}
 113
 
 
 
 
 
 
 
 114	return 0;
 115bad:
 116	return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 117}
 118
 119/*
 120 * parse a normal reply, which may contain a (dir+)dentry and/or a
 121 * target inode.
 122 */
 123static int parse_reply_info_trace(void **p, void *end,
 124				  struct ceph_mds_reply_info_parsed *info,
 125				  u64 features)
 126{
 127	int err;
 128
 129	if (info->head->is_dentry) {
 130		err = parse_reply_info_in(p, end, &info->diri, features);
 131		if (err < 0)
 132			goto out_bad;
 133
 134		if (unlikely(*p + sizeof(*info->dirfrag) > end))
 135			goto bad;
 136		info->dirfrag = *p;
 137		*p += sizeof(*info->dirfrag) +
 138			sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 139		if (unlikely(*p > end))
 140			goto bad;
 141
 142		ceph_decode_32_safe(p, end, info->dname_len, bad);
 143		ceph_decode_need(p, end, info->dname_len, bad);
 144		info->dname = *p;
 145		*p += info->dname_len;
 146		info->dlease = *p;
 147		*p += sizeof(*info->dlease);
 
 
 148	}
 149
 150	if (info->head->is_target) {
 151		err = parse_reply_info_in(p, end, &info->targeti, features);
 152		if (err < 0)
 153			goto out_bad;
 154	}
 155
 156	if (unlikely(*p != end))
 157		goto bad;
 158	return 0;
 159
 160bad:
 161	err = -EIO;
 162out_bad:
 163	pr_err("problem parsing mds trace %d\n", err);
 164	return err;
 165}
 166
 167/*
 168 * parse readdir results
 169 */
 170static int parse_reply_info_dir(void **p, void *end,
 171				struct ceph_mds_reply_info_parsed *info,
 172				u64 features)
 173{
 174	u32 num, i = 0;
 175	int err;
 176
 177	info->dir_dir = *p;
 178	if (*p + sizeof(*info->dir_dir) > end)
 179		goto bad;
 180	*p += sizeof(*info->dir_dir) +
 181		sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 182	if (*p > end)
 183		goto bad;
 184
 185	ceph_decode_need(p, end, sizeof(num) + 2, bad);
 186	num = ceph_decode_32(p);
 187	{
 188		u16 flags = ceph_decode_16(p);
 189		info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 190		info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 191		info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 
 192	}
 193	if (num == 0)
 194		goto done;
 195
 196	BUG_ON(!info->dir_entries);
 197	if ((unsigned long)(info->dir_entries + num) >
 198	    (unsigned long)info->dir_entries + info->dir_buf_size) {
 199		pr_err("dir contents are larger than expected\n");
 200		WARN_ON(1);
 201		goto bad;
 202	}
 203
 204	info->dir_nr = num;
 205	while (num) {
 206		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 207		/* dentry */
 208		ceph_decode_need(p, end, sizeof(u32)*2, bad);
 209		rde->name_len = ceph_decode_32(p);
 210		ceph_decode_need(p, end, rde->name_len, bad);
 211		rde->name = *p;
 212		*p += rde->name_len;
 213		dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 214		rde->lease = *p;
 215		*p += sizeof(struct ceph_mds_reply_lease);
 216
 
 
 
 
 217		/* inode */
 218		err = parse_reply_info_in(p, end, &rde->inode, features);
 219		if (err < 0)
 220			goto out_bad;
 221		/* ceph_readdir_prepopulate() will update it */
 222		rde->offset = 0;
 223		i++;
 224		num--;
 225	}
 226
 227done:
 228	if (*p != end)
 229		goto bad;
 230	return 0;
 231
 232bad:
 233	err = -EIO;
 234out_bad:
 235	pr_err("problem parsing dir contents %d\n", err);
 236	return err;
 237}
 238
 239/*
 240 * parse fcntl F_GETLK results
 241 */
 242static int parse_reply_info_filelock(void **p, void *end,
 243				     struct ceph_mds_reply_info_parsed *info,
 244				     u64 features)
 245{
 246	if (*p + sizeof(*info->filelock_reply) > end)
 247		goto bad;
 248
 249	info->filelock_reply = *p;
 250	*p += sizeof(*info->filelock_reply);
 251
 252	if (unlikely(*p != end))
 253		goto bad;
 254	return 0;
 255
 256bad:
 257	return -EIO;
 258}
 259
 260/*
 261 * parse create results
 262 */
 263static int parse_reply_info_create(void **p, void *end,
 264				  struct ceph_mds_reply_info_parsed *info,
 265				  u64 features)
 266{
 267	if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 
 
 268		if (*p == end) {
 269			info->has_create_ino = false;
 270		} else {
 271			info->has_create_ino = true;
 272			info->ino = ceph_decode_64(p);
 273		}
 
 
 
 274	}
 275
 276	if (unlikely(*p != end))
 277		goto bad;
 278	return 0;
 279
 280bad:
 281	return -EIO;
 282}
 283
 284/*
 285 * parse extra results
 286 */
 287static int parse_reply_info_extra(void **p, void *end,
 288				  struct ceph_mds_reply_info_parsed *info,
 289				  u64 features)
 290{
 291	u32 op = le32_to_cpu(info->head->op);
 292
 293	if (op == CEPH_MDS_OP_GETFILELOCK)
 294		return parse_reply_info_filelock(p, end, info, features);
 295	else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 296		return parse_reply_info_dir(p, end, info, features);
 297	else if (op == CEPH_MDS_OP_CREATE)
 298		return parse_reply_info_create(p, end, info, features);
 299	else
 300		return -EIO;
 301}
 302
 303/*
 304 * parse entire mds reply
 305 */
 306static int parse_reply_info(struct ceph_msg *msg,
 307			    struct ceph_mds_reply_info_parsed *info,
 308			    u64 features)
 309{
 310	void *p, *end;
 311	u32 len;
 312	int err;
 313
 314	info->head = msg->front.iov_base;
 315	p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 316	end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 317
 318	/* trace */
 319	ceph_decode_32_safe(&p, end, len, bad);
 320	if (len > 0) {
 321		ceph_decode_need(&p, end, len, bad);
 322		err = parse_reply_info_trace(&p, p+len, info, features);
 323		if (err < 0)
 324			goto out_bad;
 325	}
 326
 327	/* extra */
 328	ceph_decode_32_safe(&p, end, len, bad);
 329	if (len > 0) {
 330		ceph_decode_need(&p, end, len, bad);
 331		err = parse_reply_info_extra(&p, p+len, info, features);
 332		if (err < 0)
 333			goto out_bad;
 334	}
 335
 336	/* snap blob */
 337	ceph_decode_32_safe(&p, end, len, bad);
 338	info->snapblob_len = len;
 339	info->snapblob = p;
 340	p += len;
 341
 342	if (p != end)
 343		goto bad;
 344	return 0;
 345
 346bad:
 347	err = -EIO;
 348out_bad:
 349	pr_err("mds parse_reply err %d\n", err);
 350	return err;
 351}
 352
 353static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 354{
 355	if (!info->dir_entries)
 356		return;
 357	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 358}
 359
 360
 361/*
 362 * sessions
 363 */
 364const char *ceph_session_state_name(int s)
 365{
 366	switch (s) {
 367	case CEPH_MDS_SESSION_NEW: return "new";
 368	case CEPH_MDS_SESSION_OPENING: return "opening";
 369	case CEPH_MDS_SESSION_OPEN: return "open";
 370	case CEPH_MDS_SESSION_HUNG: return "hung";
 371	case CEPH_MDS_SESSION_CLOSING: return "closing";
 372	case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 373	case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 374	case CEPH_MDS_SESSION_REJECTED: return "rejected";
 375	default: return "???";
 376	}
 377}
 378
 379static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 380{
 381	if (atomic_inc_not_zero(&s->s_ref)) {
 382		dout("mdsc get_session %p %d -> %d\n", s,
 383		     atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 384		return s;
 385	} else {
 386		dout("mdsc get_session %p 0 -- FAIL", s);
 387		return NULL;
 388	}
 389}
 390
 391void ceph_put_mds_session(struct ceph_mds_session *s)
 392{
 393	dout("mdsc put_session %p %d -> %d\n", s,
 394	     atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 395	if (atomic_dec_and_test(&s->s_ref)) {
 396		if (s->s_auth.authorizer)
 397			ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 398		kfree(s);
 399	}
 400}
 401
 402/*
 403 * called under mdsc->mutex
 404 */
 405struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 406						   int mds)
 407{
 408	struct ceph_mds_session *session;
 409
 410	if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 411		return NULL;
 412	session = mdsc->sessions[mds];
 413	dout("lookup_mds_session %p %d\n", session,
 414	     atomic_read(&session->s_ref));
 415	get_session(session);
 416	return session;
 417}
 418
 419static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 420{
 421	if (mds >= mdsc->max_sessions)
 422		return false;
 423	return mdsc->sessions[mds];
 
 424}
 425
 426static int __verify_registered_session(struct ceph_mds_client *mdsc,
 427				       struct ceph_mds_session *s)
 428{
 429	if (s->s_mds >= mdsc->max_sessions ||
 430	    mdsc->sessions[s->s_mds] != s)
 431		return -ENOENT;
 432	return 0;
 433}
 434
 435/*
 436 * create+register a new session for given mds.
 437 * called under mdsc->mutex.
 438 */
 439static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 440						 int mds)
 441{
 442	struct ceph_mds_session *s;
 443
 444	if (mds >= mdsc->mdsmap->m_max_mds)
 445		return ERR_PTR(-EINVAL);
 446
 447	s = kzalloc(sizeof(*s), GFP_NOFS);
 448	if (!s)
 449		return ERR_PTR(-ENOMEM);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 450	s->s_mdsc = mdsc;
 451	s->s_mds = mds;
 452	s->s_state = CEPH_MDS_SESSION_NEW;
 453	s->s_ttl = 0;
 454	s->s_seq = 0;
 455	mutex_init(&s->s_mutex);
 456
 457	ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 458
 459	spin_lock_init(&s->s_gen_ttl_lock);
 460	s->s_cap_gen = 0;
 461	s->s_cap_ttl = jiffies - 1;
 462
 463	spin_lock_init(&s->s_cap_lock);
 464	s->s_renew_requested = 0;
 465	s->s_renew_seq = 0;
 466	INIT_LIST_HEAD(&s->s_caps);
 467	s->s_nr_caps = 0;
 468	s->s_trim_caps = 0;
 469	atomic_set(&s->s_ref, 1);
 470	INIT_LIST_HEAD(&s->s_waiting);
 471	INIT_LIST_HEAD(&s->s_unsafe);
 472	s->s_num_cap_releases = 0;
 473	s->s_cap_reconnect = 0;
 474	s->s_cap_iterator = NULL;
 475	INIT_LIST_HEAD(&s->s_cap_releases);
 
 
 476	INIT_LIST_HEAD(&s->s_cap_flushing);
 477
 478	dout("register_session mds%d\n", mds);
 479	if (mds >= mdsc->max_sessions) {
 480		int newmax = 1 << get_count_order(mds+1);
 481		struct ceph_mds_session **sa;
 482
 483		dout("register_session realloc to %d\n", newmax);
 484		sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 485		if (sa == NULL)
 486			goto fail_realloc;
 487		if (mdsc->sessions) {
 488			memcpy(sa, mdsc->sessions,
 489			       mdsc->max_sessions * sizeof(void *));
 490			kfree(mdsc->sessions);
 491		}
 492		mdsc->sessions = sa;
 493		mdsc->max_sessions = newmax;
 494	}
 495	mdsc->sessions[mds] = s;
 496	atomic_inc(&mdsc->num_sessions);
 497	atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 498
 499	ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 500		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 501
 502	return s;
 503
 504fail_realloc:
 505	kfree(s);
 506	return ERR_PTR(-ENOMEM);
 507}
 508
 509/*
 510 * called under mdsc->mutex
 511 */
 512static void __unregister_session(struct ceph_mds_client *mdsc,
 513			       struct ceph_mds_session *s)
 514{
 515	dout("__unregister_session mds%d %p\n", s->s_mds, s);
 516	BUG_ON(mdsc->sessions[s->s_mds] != s);
 517	mdsc->sessions[s->s_mds] = NULL;
 
 518	ceph_con_close(&s->s_con);
 519	ceph_put_mds_session(s);
 520	atomic_dec(&mdsc->num_sessions);
 521}
 522
 523/*
 524 * drop session refs in request.
 525 *
 526 * should be last request ref, or hold mdsc->mutex
 527 */
 528static void put_request_session(struct ceph_mds_request *req)
 529{
 530	if (req->r_session) {
 531		ceph_put_mds_session(req->r_session);
 532		req->r_session = NULL;
 533	}
 534}
 535
 536void ceph_mdsc_release_request(struct kref *kref)
 537{
 538	struct ceph_mds_request *req = container_of(kref,
 539						    struct ceph_mds_request,
 540						    r_kref);
 541	destroy_reply_info(&req->r_reply_info);
 542	if (req->r_request)
 543		ceph_msg_put(req->r_request);
 544	if (req->r_reply)
 545		ceph_msg_put(req->r_reply);
 546	if (req->r_inode) {
 547		ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 548		iput(req->r_inode);
 
 549	}
 550	if (req->r_locked_dir)
 551		ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 552	iput(req->r_target_inode);
 553	if (req->r_dentry)
 554		dput(req->r_dentry);
 555	if (req->r_old_dentry)
 556		dput(req->r_old_dentry);
 557	if (req->r_old_dentry_dir) {
 558		/*
 559		 * track (and drop pins for) r_old_dentry_dir
 560		 * separately, since r_old_dentry's d_parent may have
 561		 * changed between the dir mutex being dropped and
 562		 * this request being freed.
 563		 */
 564		ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 565				  CEPH_CAP_PIN);
 566		iput(req->r_old_dentry_dir);
 567	}
 568	kfree(req->r_path1);
 569	kfree(req->r_path2);
 570	if (req->r_pagelist)
 571		ceph_pagelist_release(req->r_pagelist);
 572	put_request_session(req);
 573	ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 
 574	kfree(req);
 575}
 576
 577DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 578
 579/*
 580 * lookup session, bump ref if found.
 581 *
 582 * called under mdsc->mutex.
 583 */
 584static struct ceph_mds_request *
 585lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 586{
 587	struct ceph_mds_request *req;
 588
 589	req = lookup_request(&mdsc->request_tree, tid);
 590	if (req)
 591		ceph_mdsc_get_request(req);
 592
 593	return req;
 594}
 595
 596/*
 597 * Register an in-flight request, and assign a tid.  Link to directory
 598 * are modifying (if any).
 599 *
 600 * Called under mdsc->mutex.
 601 */
 602static void __register_request(struct ceph_mds_client *mdsc,
 603			       struct ceph_mds_request *req,
 604			       struct inode *dir)
 605{
 
 
 606	req->r_tid = ++mdsc->last_tid;
 607	if (req->r_num_caps)
 608		ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 609				  req->r_num_caps);
 
 
 
 
 
 
 
 
 610	dout("__register_request %p tid %lld\n", req, req->r_tid);
 611	ceph_mdsc_get_request(req);
 612	insert_request(&mdsc->request_tree, req);
 613
 614	req->r_uid = current_fsuid();
 615	req->r_gid = current_fsgid();
 616
 617	if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 618		mdsc->oldest_tid = req->r_tid;
 619
 620	if (dir) {
 621		ihold(dir);
 622		req->r_unsafe_dir = dir;
 623	}
 624}
 625
 626static void __unregister_request(struct ceph_mds_client *mdsc,
 627				 struct ceph_mds_request *req)
 628{
 629	dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 630
 631	/* Never leave an unregistered request on an unsafe list! */
 632	list_del_init(&req->r_unsafe_item);
 633
 634	if (req->r_tid == mdsc->oldest_tid) {
 635		struct rb_node *p = rb_next(&req->r_node);
 636		mdsc->oldest_tid = 0;
 637		while (p) {
 638			struct ceph_mds_request *next_req =
 639				rb_entry(p, struct ceph_mds_request, r_node);
 640			if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 641				mdsc->oldest_tid = next_req->r_tid;
 642				break;
 643			}
 644			p = rb_next(p);
 645		}
 646	}
 647
 648	erase_request(&mdsc->request_tree, req);
 649
 650	if (req->r_unsafe_dir && req->r_got_unsafe) {
 
 651		struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 652		spin_lock(&ci->i_unsafe_lock);
 653		list_del_init(&req->r_unsafe_dir_item);
 654		spin_unlock(&ci->i_unsafe_lock);
 655	}
 656	if (req->r_target_inode && req->r_got_unsafe) {
 
 657		struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 658		spin_lock(&ci->i_unsafe_lock);
 659		list_del_init(&req->r_unsafe_target_item);
 660		spin_unlock(&ci->i_unsafe_lock);
 661	}
 662
 663	if (req->r_unsafe_dir) {
 664		iput(req->r_unsafe_dir);
 
 665		req->r_unsafe_dir = NULL;
 666	}
 667
 668	complete_all(&req->r_safe_completion);
 669
 670	ceph_mdsc_put_request(req);
 671}
 672
 673/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 674 * Choose mds to send request to next.  If there is a hint set in the
 675 * request (e.g., due to a prior forward hint from the mds), use that.
 676 * Otherwise, consult frag tree and/or caps to identify the
 677 * appropriate mds.  If all else fails, choose randomly.
 678 *
 679 * Called under mdsc->mutex.
 680 */
 681static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 682{
 683	/*
 684	 * we don't need to worry about protecting the d_parent access
 685	 * here because we never renaming inside the snapped namespace
 686	 * except to resplice to another snapdir, and either the old or new
 687	 * result is a valid result.
 688	 */
 689	while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 690		dentry = dentry->d_parent;
 691	return dentry;
 692}
 693
 694static int __choose_mds(struct ceph_mds_client *mdsc,
 695			struct ceph_mds_request *req)
 696{
 697	struct inode *inode;
 698	struct ceph_inode_info *ci;
 699	struct ceph_cap *cap;
 700	int mode = req->r_direct_mode;
 701	int mds = -1;
 702	u32 hash = req->r_direct_hash;
 703	bool is_hash = req->r_direct_is_hash;
 704
 705	/*
 706	 * is there a specific mds we should try?  ignore hint if we have
 707	 * no session and the mds is not up (active or recovering).
 708	 */
 709	if (req->r_resend_mds >= 0 &&
 710	    (__have_session(mdsc, req->r_resend_mds) ||
 711	     ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 712		dout("choose_mds using resend_mds mds%d\n",
 713		     req->r_resend_mds);
 714		return req->r_resend_mds;
 715	}
 716
 717	if (mode == USE_RANDOM_MDS)
 718		goto random;
 719
 720	inode = NULL;
 721	if (req->r_inode) {
 722		inode = req->r_inode;
 
 
 
 
 
 
 
 
 
 723	} else if (req->r_dentry) {
 724		/* ignore race with rename; old or new d_parent is okay */
 725		struct dentry *parent = req->r_dentry->d_parent;
 726		struct inode *dir = d_inode(parent);
 
 
 
 
 727
 728		if (dir->i_sb != mdsc->fsc->sb) {
 729			/* not this fs! */
 730			inode = d_inode(req->r_dentry);
 
 
 731		} else if (ceph_snap(dir) != CEPH_NOSNAP) {
 732			/* direct snapped/virtual snapdir requests
 733			 * based on parent dir inode */
 734			struct dentry *dn = get_nonsnap_parent(parent);
 735			inode = d_inode(dn);
 736			dout("__choose_mds using nonsnap parent %p\n", inode);
 737		} else {
 738			/* dentry target */
 739			inode = d_inode(req->r_dentry);
 740			if (!inode || mode == USE_AUTH_MDS) {
 741				/* dir + name */
 742				inode = dir;
 743				hash = ceph_dentry_hash(dir, req->r_dentry);
 744				is_hash = true;
 
 
 745			}
 746		}
 
 747	}
 748
 749	dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 750	     (int)hash, mode);
 751	if (!inode)
 752		goto random;
 753	ci = ceph_inode(inode);
 754
 755	if (is_hash && S_ISDIR(inode->i_mode)) {
 756		struct ceph_inode_frag frag;
 757		int found;
 758
 759		ceph_choose_frag(ci, hash, &frag, &found);
 760		if (found) {
 761			if (mode == USE_ANY_MDS && frag.ndist > 0) {
 762				u8 r;
 763
 764				/* choose a random replica */
 765				get_random_bytes(&r, 1);
 766				r %= frag.ndist;
 767				mds = frag.dist[r];
 768				dout("choose_mds %p %llx.%llx "
 769				     "frag %u mds%d (%d/%d)\n",
 770				     inode, ceph_vinop(inode),
 771				     frag.frag, mds,
 772				     (int)r, frag.ndist);
 773				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 774				    CEPH_MDS_STATE_ACTIVE)
 775					return mds;
 776			}
 777
 778			/* since this file/dir wasn't known to be
 779			 * replicated, then we want to look for the
 780			 * authoritative mds. */
 781			mode = USE_AUTH_MDS;
 782			if (frag.mds >= 0) {
 783				/* choose auth mds */
 784				mds = frag.mds;
 785				dout("choose_mds %p %llx.%llx "
 786				     "frag %u mds%d (auth)\n",
 787				     inode, ceph_vinop(inode), frag.frag, mds);
 788				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 789				    CEPH_MDS_STATE_ACTIVE)
 790					return mds;
 791			}
 792		}
 793	}
 794
 795	spin_lock(&ci->i_ceph_lock);
 796	cap = NULL;
 797	if (mode == USE_AUTH_MDS)
 798		cap = ci->i_auth_cap;
 799	if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 800		cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 801	if (!cap) {
 802		spin_unlock(&ci->i_ceph_lock);
 
 803		goto random;
 804	}
 805	mds = cap->session->s_mds;
 806	dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 807	     inode, ceph_vinop(inode), mds,
 808	     cap == ci->i_auth_cap ? "auth " : "", cap);
 809	spin_unlock(&ci->i_ceph_lock);
 
 
 
 
 810	return mds;
 811
 812random:
 813	mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 814	dout("choose_mds chose random mds%d\n", mds);
 815	return mds;
 816}
 817
 818
 819/*
 820 * session messages
 821 */
 822static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 823{
 824	struct ceph_msg *msg;
 825	struct ceph_mds_session_head *h;
 826
 827	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 828			   false);
 829	if (!msg) {
 830		pr_err("create_session_msg ENOMEM creating msg\n");
 831		return NULL;
 832	}
 833	h = msg->front.iov_base;
 834	h->op = cpu_to_le32(op);
 835	h->seq = cpu_to_le64(seq);
 836
 837	return msg;
 838}
 839
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 840/*
 841 * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 842 * to include additional client metadata fields.
 843 */
 844static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 845{
 846	struct ceph_msg *msg;
 847	struct ceph_mds_session_head *h;
 848	int i = -1;
 849	int metadata_bytes = 0;
 850	int metadata_key_count = 0;
 851	struct ceph_options *opt = mdsc->fsc->client->options;
 852	struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
 853	void *p;
 854
 855	const char* metadata[][2] = {
 856		{"hostname", utsname()->nodename},
 857		{"kernel_version", utsname()->release},
 858		{"entity_id", opt->name ? : ""},
 859		{"root", fsopt->server_path ? : "/"},
 860		{NULL, NULL}
 861	};
 862
 863	/* Calculate serialized length of metadata */
 864	metadata_bytes = 4;  /* map length */
 865	for (i = 0; metadata[i][0] != NULL; ++i) {
 866		metadata_bytes += 8 + strlen(metadata[i][0]) +
 867			strlen(metadata[i][1]);
 868		metadata_key_count++;
 869	}
 
 
 870
 871	/* Allocate the message */
 872	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 873			   GFP_NOFS, false);
 874	if (!msg) {
 875		pr_err("create_session_msg ENOMEM creating msg\n");
 876		return NULL;
 877	}
 878	h = msg->front.iov_base;
 
 
 
 879	h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 880	h->seq = cpu_to_le64(seq);
 881
 882	/*
 883	 * Serialize client metadata into waiting buffer space, using
 884	 * the format that userspace expects for map<string, string>
 885	 *
 886	 * ClientSession messages with metadata are v2
 887	 */
 888	msg->hdr.version = cpu_to_le16(2);
 889	msg->hdr.compat_version = cpu_to_le16(1);
 890
 891	/* The write pointer, following the session_head structure */
 892	p = msg->front.iov_base + sizeof(*h);
 893
 894	/* Number of entries in the map */
 895	ceph_encode_32(&p, metadata_key_count);
 896
 897	/* Two length-prefixed strings for each entry in the map */
 898	for (i = 0; metadata[i][0] != NULL; ++i) {
 899		size_t const key_len = strlen(metadata[i][0]);
 900		size_t const val_len = strlen(metadata[i][1]);
 901
 902		ceph_encode_32(&p, key_len);
 903		memcpy(p, metadata[i][0], key_len);
 904		p += key_len;
 905		ceph_encode_32(&p, val_len);
 906		memcpy(p, metadata[i][1], val_len);
 907		p += val_len;
 908	}
 909
 
 
 
 
 910	return msg;
 911}
 912
 913/*
 914 * send session open request.
 915 *
 916 * called under mdsc->mutex
 917 */
 918static int __open_session(struct ceph_mds_client *mdsc,
 919			  struct ceph_mds_session *session)
 920{
 921	struct ceph_msg *msg;
 922	int mstate;
 923	int mds = session->s_mds;
 924
 925	/* wait for mds to go active? */
 926	mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 927	dout("open_session to mds%d (%s)\n", mds,
 928	     ceph_mds_state_name(mstate));
 929	session->s_state = CEPH_MDS_SESSION_OPENING;
 930	session->s_renew_requested = jiffies;
 931
 932	/* send connect message */
 933	msg = create_session_open_msg(mdsc, session->s_seq);
 934	if (!msg)
 935		return -ENOMEM;
 936	ceph_con_send(&session->s_con, msg);
 937	return 0;
 938}
 939
 940/*
 941 * open sessions for any export targets for the given mds
 942 *
 943 * called under mdsc->mutex
 944 */
 945static struct ceph_mds_session *
 946__open_export_target_session(struct ceph_mds_client *mdsc, int target)
 947{
 948	struct ceph_mds_session *session;
 949
 950	session = __ceph_lookup_mds_session(mdsc, target);
 951	if (!session) {
 952		session = register_session(mdsc, target);
 953		if (IS_ERR(session))
 954			return session;
 955	}
 956	if (session->s_state == CEPH_MDS_SESSION_NEW ||
 957	    session->s_state == CEPH_MDS_SESSION_CLOSING)
 958		__open_session(mdsc, session);
 959
 960	return session;
 961}
 962
 963struct ceph_mds_session *
 964ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 965{
 966	struct ceph_mds_session *session;
 967
 968	dout("open_export_target_session to mds%d\n", target);
 969
 970	mutex_lock(&mdsc->mutex);
 971	session = __open_export_target_session(mdsc, target);
 972	mutex_unlock(&mdsc->mutex);
 973
 974	return session;
 975}
 976
 977static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 978					  struct ceph_mds_session *session)
 979{
 980	struct ceph_mds_info *mi;
 981	struct ceph_mds_session *ts;
 982	int i, mds = session->s_mds;
 983
 984	if (mds >= mdsc->mdsmap->m_max_mds)
 985		return;
 986
 987	mi = &mdsc->mdsmap->m_info[mds];
 988	dout("open_export_target_sessions for mds%d (%d targets)\n",
 989	     session->s_mds, mi->num_export_targets);
 990
 991	for (i = 0; i < mi->num_export_targets; i++) {
 992		ts = __open_export_target_session(mdsc, mi->export_targets[i]);
 993		if (!IS_ERR(ts))
 994			ceph_put_mds_session(ts);
 995	}
 996}
 997
 998void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 999					   struct ceph_mds_session *session)
1000{
1001	mutex_lock(&mdsc->mutex);
1002	__open_export_target_sessions(mdsc, session);
1003	mutex_unlock(&mdsc->mutex);
1004}
1005
1006/*
1007 * session caps
1008 */
1009
1010/* caller holds s_cap_lock, we drop it */
1011static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1012				 struct ceph_mds_session *session)
1013	__releases(session->s_cap_lock)
1014{
1015	LIST_HEAD(tmp_list);
1016	list_splice_init(&session->s_cap_releases, &tmp_list);
 
1017	session->s_num_cap_releases = 0;
1018	spin_unlock(&session->s_cap_lock);
 
1019
1020	dout("cleanup_cap_releases mds%d\n", session->s_mds);
1021	while (!list_empty(&tmp_list)) {
 
 
1022		struct ceph_cap *cap;
1023		/* zero out the in-progress message */
1024		cap = list_first_entry(&tmp_list,
1025					struct ceph_cap, session_caps);
1026		list_del(&cap->session_caps);
1027		ceph_put_cap(mdsc, cap);
1028	}
1029}
1030
1031static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1032				     struct ceph_mds_session *session)
1033{
1034	struct ceph_mds_request *req;
1035	struct rb_node *p;
 
1036
1037	dout("cleanup_session_requests mds%d\n", session->s_mds);
1038	mutex_lock(&mdsc->mutex);
1039	while (!list_empty(&session->s_unsafe)) {
1040		req = list_first_entry(&session->s_unsafe,
1041				       struct ceph_mds_request, r_unsafe_item);
1042		pr_warn_ratelimited(" dropping unsafe request %llu\n",
1043				    req->r_tid);
 
 
 
 
 
 
 
 
 
 
1044		__unregister_request(mdsc, req);
1045	}
1046	/* zero r_attempts, so kick_requests() will re-send requests */
1047	p = rb_first(&mdsc->request_tree);
1048	while (p) {
1049		req = rb_entry(p, struct ceph_mds_request, r_node);
1050		p = rb_next(p);
1051		if (req->r_session &&
1052		    req->r_session->s_mds == session->s_mds)
1053			req->r_attempts = 0;
1054	}
1055	mutex_unlock(&mdsc->mutex);
1056}
1057
1058/*
1059 * Helper to safely iterate over all caps associated with a session, with
1060 * special care taken to handle a racing __ceph_remove_cap().
1061 *
1062 * Caller must hold session s_mutex.
1063 */
1064static int iterate_session_caps(struct ceph_mds_session *session,
1065				 int (*cb)(struct inode *, struct ceph_cap *,
1066					    void *), void *arg)
1067{
1068	struct list_head *p;
1069	struct ceph_cap *cap;
1070	struct inode *inode, *last_inode = NULL;
1071	struct ceph_cap *old_cap = NULL;
1072	int ret;
1073
1074	dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1075	spin_lock(&session->s_cap_lock);
1076	p = session->s_caps.next;
1077	while (p != &session->s_caps) {
1078		cap = list_entry(p, struct ceph_cap, session_caps);
1079		inode = igrab(&cap->ci->vfs_inode);
1080		if (!inode) {
1081			p = p->next;
1082			continue;
1083		}
1084		session->s_cap_iterator = cap;
1085		spin_unlock(&session->s_cap_lock);
1086
1087		if (last_inode) {
1088			iput(last_inode);
 
 
1089			last_inode = NULL;
1090		}
1091		if (old_cap) {
1092			ceph_put_cap(session->s_mdsc, old_cap);
1093			old_cap = NULL;
1094		}
1095
1096		ret = cb(inode, cap, arg);
1097		last_inode = inode;
1098
1099		spin_lock(&session->s_cap_lock);
1100		p = p->next;
1101		if (cap->ci == NULL) {
1102			dout("iterate_session_caps  finishing cap %p removal\n",
1103			     cap);
1104			BUG_ON(cap->session != session);
1105			cap->session = NULL;
1106			list_del_init(&cap->session_caps);
1107			session->s_nr_caps--;
1108			if (cap->queue_release) {
1109				list_add_tail(&cap->session_caps,
1110					      &session->s_cap_releases);
1111				session->s_num_cap_releases++;
1112			} else {
1113				old_cap = cap;  /* put_cap it w/o locks held */
1114			}
1115		}
1116		if (ret < 0)
1117			goto out;
1118	}
1119	ret = 0;
1120out:
1121	session->s_cap_iterator = NULL;
1122	spin_unlock(&session->s_cap_lock);
1123
1124	iput(last_inode);
1125	if (old_cap)
1126		ceph_put_cap(session->s_mdsc, old_cap);
1127
1128	return ret;
1129}
1130
1131static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1132				  void *arg)
1133{
1134	struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1135	struct ceph_inode_info *ci = ceph_inode(inode);
1136	LIST_HEAD(to_remove);
1137	bool drop = false;
1138	bool invalidate = false;
1139
1140	dout("removing cap %p, ci is %p, inode is %p\n",
1141	     cap, ci, &ci->vfs_inode);
1142	spin_lock(&ci->i_ceph_lock);
 
 
1143	__ceph_remove_cap(cap, false);
1144	if (!ci->i_auth_cap) {
1145		struct ceph_cap_flush *cf;
1146		struct ceph_mds_client *mdsc = fsc->mdsc;
1147
1148		ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1149
1150		if (ci->i_wrbuffer_ref > 0 &&
1151		    ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
1152			invalidate = true;
 
1153
1154		while (!list_empty(&ci->i_cap_flush_list)) {
1155			cf = list_first_entry(&ci->i_cap_flush_list,
1156					      struct ceph_cap_flush, i_list);
1157			list_move(&cf->i_list, &to_remove);
1158		}
1159
1160		spin_lock(&mdsc->cap_dirty_lock);
1161
1162		list_for_each_entry(cf, &to_remove, i_list)
1163			list_del(&cf->g_list);
1164
1165		if (!list_empty(&ci->i_dirty_item)) {
1166			pr_warn_ratelimited(
1167				" dropping dirty %s state for %p %lld\n",
1168				ceph_cap_string(ci->i_dirty_caps),
1169				inode, ceph_ino(inode));
1170			ci->i_dirty_caps = 0;
1171			list_del_init(&ci->i_dirty_item);
1172			drop = true;
1173		}
1174		if (!list_empty(&ci->i_flushing_item)) {
1175			pr_warn_ratelimited(
1176				" dropping dirty+flushing %s state for %p %lld\n",
1177				ceph_cap_string(ci->i_flushing_caps),
1178				inode, ceph_ino(inode));
1179			ci->i_flushing_caps = 0;
1180			list_del_init(&ci->i_flushing_item);
1181			mdsc->num_cap_flushing--;
1182			drop = true;
1183		}
1184		spin_unlock(&mdsc->cap_dirty_lock);
1185
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1186		if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1187			list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1188			ci->i_prealloc_cap_flush = NULL;
1189		}
1190	}
1191	spin_unlock(&ci->i_ceph_lock);
1192	while (!list_empty(&to_remove)) {
1193		struct ceph_cap_flush *cf;
1194		cf = list_first_entry(&to_remove,
1195				      struct ceph_cap_flush, i_list);
1196		list_del(&cf->i_list);
1197		ceph_free_cap_flush(cf);
1198	}
1199
1200	wake_up_all(&ci->i_cap_wq);
1201	if (invalidate)
1202		ceph_queue_invalidate(inode);
1203	if (drop)
1204		iput(inode);
1205	return 0;
1206}
1207
1208/*
1209 * caller must hold session s_mutex
1210 */
1211static void remove_session_caps(struct ceph_mds_session *session)
1212{
1213	struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1214	struct super_block *sb = fsc->sb;
 
 
1215	dout("remove_session_caps on %p\n", session);
1216	iterate_session_caps(session, remove_session_caps_cb, fsc);
1217
1218	wake_up_all(&fsc->mdsc->cap_flushing_wq);
1219
1220	spin_lock(&session->s_cap_lock);
1221	if (session->s_nr_caps > 0) {
1222		struct inode *inode;
1223		struct ceph_cap *cap, *prev = NULL;
1224		struct ceph_vino vino;
1225		/*
1226		 * iterate_session_caps() skips inodes that are being
1227		 * deleted, we need to wait until deletions are complete.
1228		 * __wait_on_freeing_inode() is designed for the job,
1229		 * but it is not exported, so use lookup inode function
1230		 * to access it.
1231		 */
1232		while (!list_empty(&session->s_caps)) {
1233			cap = list_entry(session->s_caps.next,
1234					 struct ceph_cap, session_caps);
1235			if (cap == prev)
1236				break;
1237			prev = cap;
1238			vino = cap->ci->i_vino;
1239			spin_unlock(&session->s_cap_lock);
1240
1241			inode = ceph_find_inode(sb, vino);
1242			iput(inode);
 
1243
1244			spin_lock(&session->s_cap_lock);
1245		}
1246	}
1247
1248	// drop cap expires and unlock s_cap_lock
1249	cleanup_cap_releases(session->s_mdsc, session);
1250
1251	BUG_ON(session->s_nr_caps > 0);
1252	BUG_ON(!list_empty(&session->s_cap_flushing));
 
 
1253}
1254
 
 
 
 
 
 
1255/*
1256 * wake up any threads waiting on this session's caps.  if the cap is
1257 * old (didn't get renewed on the client reconnect), remove it now.
1258 *
1259 * caller must hold s_mutex.
1260 */
1261static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1262			      void *arg)
1263{
1264	struct ceph_inode_info *ci = ceph_inode(inode);
 
1265
1266	if (arg) {
1267		spin_lock(&ci->i_ceph_lock);
1268		ci->i_wanted_max_size = 0;
1269		ci->i_requested_max_size = 0;
1270		spin_unlock(&ci->i_ceph_lock);
 
 
 
 
 
 
 
 
 
 
 
1271	}
1272	wake_up_all(&ci->i_cap_wq);
1273	return 0;
1274}
1275
1276static void wake_up_session_caps(struct ceph_mds_session *session,
1277				 int reconnect)
1278{
1279	dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1280	iterate_session_caps(session, wake_up_session_cb,
1281			     (void *)(unsigned long)reconnect);
1282}
1283
1284/*
1285 * Send periodic message to MDS renewing all currently held caps.  The
1286 * ack will reset the expiration for all caps from this session.
1287 *
1288 * caller holds s_mutex
1289 */
1290static int send_renew_caps(struct ceph_mds_client *mdsc,
1291			   struct ceph_mds_session *session)
1292{
1293	struct ceph_msg *msg;
1294	int state;
1295
1296	if (time_after_eq(jiffies, session->s_cap_ttl) &&
1297	    time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1298		pr_info("mds%d caps stale\n", session->s_mds);
1299	session->s_renew_requested = jiffies;
1300
1301	/* do not try to renew caps until a recovering mds has reconnected
1302	 * with its clients. */
1303	state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1304	if (state < CEPH_MDS_STATE_RECONNECT) {
1305		dout("send_renew_caps ignoring mds%d (%s)\n",
1306		     session->s_mds, ceph_mds_state_name(state));
1307		return 0;
1308	}
1309
1310	dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1311		ceph_mds_state_name(state));
1312	msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1313				 ++session->s_renew_seq);
1314	if (!msg)
1315		return -ENOMEM;
1316	ceph_con_send(&session->s_con, msg);
1317	return 0;
1318}
1319
1320static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1321			     struct ceph_mds_session *session, u64 seq)
1322{
1323	struct ceph_msg *msg;
1324
1325	dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1326	     session->s_mds, ceph_session_state_name(session->s_state), seq);
1327	msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1328	if (!msg)
1329		return -ENOMEM;
1330	ceph_con_send(&session->s_con, msg);
1331	return 0;
1332}
1333
1334
1335/*
1336 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1337 *
1338 * Called under session->s_mutex
1339 */
1340static void renewed_caps(struct ceph_mds_client *mdsc,
1341			 struct ceph_mds_session *session, int is_renew)
1342{
1343	int was_stale;
1344	int wake = 0;
1345
1346	spin_lock(&session->s_cap_lock);
1347	was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1348
1349	session->s_cap_ttl = session->s_renew_requested +
1350		mdsc->mdsmap->m_session_timeout*HZ;
1351
1352	if (was_stale) {
1353		if (time_before(jiffies, session->s_cap_ttl)) {
1354			pr_info("mds%d caps renewed\n", session->s_mds);
1355			wake = 1;
1356		} else {
1357			pr_info("mds%d caps still stale\n", session->s_mds);
1358		}
1359	}
1360	dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1361	     session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1362	     time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1363	spin_unlock(&session->s_cap_lock);
1364
1365	if (wake)
1366		wake_up_session_caps(session, 0);
1367}
1368
1369/*
1370 * send a session close request
1371 */
1372static int request_close_session(struct ceph_mds_client *mdsc,
1373				 struct ceph_mds_session *session)
1374{
1375	struct ceph_msg *msg;
1376
1377	dout("request_close_session mds%d state %s seq %lld\n",
1378	     session->s_mds, ceph_session_state_name(session->s_state),
1379	     session->s_seq);
1380	msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1381	if (!msg)
1382		return -ENOMEM;
1383	ceph_con_send(&session->s_con, msg);
1384	return 1;
1385}
1386
1387/*
1388 * Called with s_mutex held.
1389 */
1390static int __close_session(struct ceph_mds_client *mdsc,
1391			 struct ceph_mds_session *session)
1392{
1393	if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1394		return 0;
1395	session->s_state = CEPH_MDS_SESSION_CLOSING;
1396	return request_close_session(mdsc, session);
1397}
1398
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1399/*
1400 * Trim old(er) caps.
1401 *
1402 * Because we can't cache an inode without one or more caps, we do
1403 * this indirectly: if a cap is unused, we prune its aliases, at which
1404 * point the inode will hopefully get dropped to.
1405 *
1406 * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1407 * memory pressure from the MDS, though, so it needn't be perfect.
1408 */
1409static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1410{
1411	struct ceph_mds_session *session = arg;
1412	struct ceph_inode_info *ci = ceph_inode(inode);
1413	int used, wanted, oissued, mine;
1414
1415	if (session->s_trim_caps <= 0)
1416		return -1;
1417
1418	spin_lock(&ci->i_ceph_lock);
1419	mine = cap->issued | cap->implemented;
1420	used = __ceph_caps_used(ci);
1421	wanted = __ceph_caps_file_wanted(ci);
1422	oissued = __ceph_caps_issued_other(ci, cap);
1423
1424	dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1425	     inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1426	     ceph_cap_string(used), ceph_cap_string(wanted));
1427	if (cap == ci->i_auth_cap) {
1428		if (ci->i_dirty_caps || ci->i_flushing_caps ||
1429		    !list_empty(&ci->i_cap_snaps))
1430			goto out;
1431		if ((used | wanted) & CEPH_CAP_ANY_WR)
1432			goto out;
 
 
 
 
 
1433	}
1434	/* The inode has cached pages, but it's no longer used.
1435	 * we can safely drop it */
1436	if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1437	    !(oissued & CEPH_CAP_FILE_CACHE)) {
1438	  used = 0;
1439	  oissued = 0;
1440	}
1441	if ((used | wanted) & ~oissued & mine)
1442		goto out;   /* we need these caps */
1443
1444	session->s_trim_caps--;
1445	if (oissued) {
1446		/* we aren't the only cap.. just remove us */
1447		__ceph_remove_cap(cap, true);
 
1448	} else {
 
1449		/* try dropping referring dentries */
1450		spin_unlock(&ci->i_ceph_lock);
1451		d_prune_aliases(inode);
1452		dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1453		     inode, cap, atomic_read(&inode->i_count));
 
 
 
 
 
 
 
 
 
 
1454		return 0;
1455	}
1456
1457out:
1458	spin_unlock(&ci->i_ceph_lock);
1459	return 0;
1460}
1461
1462/*
1463 * Trim session cap count down to some max number.
1464 */
1465static int trim_caps(struct ceph_mds_client *mdsc,
1466		     struct ceph_mds_session *session,
1467		     int max_caps)
1468{
1469	int trim_caps = session->s_nr_caps - max_caps;
1470
1471	dout("trim_caps mds%d start: %d / %d, trim %d\n",
1472	     session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1473	if (trim_caps > 0) {
1474		session->s_trim_caps = trim_caps;
1475		iterate_session_caps(session, trim_caps_cb, session);
 
1476		dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1477		     session->s_mds, session->s_nr_caps, max_caps,
1478			trim_caps - session->s_trim_caps);
1479		session->s_trim_caps = 0;
1480	}
1481
1482	ceph_send_cap_releases(mdsc, session);
1483	return 0;
1484}
1485
1486static int check_caps_flush(struct ceph_mds_client *mdsc,
1487			    u64 want_flush_tid)
1488{
1489	int ret = 1;
1490
1491	spin_lock(&mdsc->cap_dirty_lock);
1492	if (!list_empty(&mdsc->cap_flush_list)) {
1493		struct ceph_cap_flush *cf =
1494			list_first_entry(&mdsc->cap_flush_list,
1495					 struct ceph_cap_flush, g_list);
1496		if (cf->tid <= want_flush_tid) {
1497			dout("check_caps_flush still flushing tid "
1498			     "%llu <= %llu\n", cf->tid, want_flush_tid);
1499			ret = 0;
1500		}
1501	}
1502	spin_unlock(&mdsc->cap_dirty_lock);
1503	return ret;
1504}
1505
1506/*
1507 * flush all dirty inode data to disk.
1508 *
1509 * returns true if we've flushed through want_flush_tid
1510 */
1511static void wait_caps_flush(struct ceph_mds_client *mdsc,
1512			    u64 want_flush_tid)
1513{
1514	dout("check_caps_flush want %llu\n", want_flush_tid);
1515
1516	wait_event(mdsc->cap_flushing_wq,
1517		   check_caps_flush(mdsc, want_flush_tid));
1518
1519	dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1520}
1521
1522/*
1523 * called under s_mutex
1524 */
1525void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1526			    struct ceph_mds_session *session)
1527{
1528	struct ceph_msg *msg = NULL;
1529	struct ceph_mds_cap_release *head;
1530	struct ceph_mds_cap_item *item;
 
1531	struct ceph_cap *cap;
1532	LIST_HEAD(tmp_list);
1533	int num_cap_releases;
 
 
 
 
 
1534
1535	spin_lock(&session->s_cap_lock);
1536again:
1537	list_splice_init(&session->s_cap_releases, &tmp_list);
1538	num_cap_releases = session->s_num_cap_releases;
1539	session->s_num_cap_releases = 0;
1540	spin_unlock(&session->s_cap_lock);
1541
1542	while (!list_empty(&tmp_list)) {
1543		if (!msg) {
1544			msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1545					PAGE_SIZE, GFP_NOFS, false);
1546			if (!msg)
1547				goto out_err;
1548			head = msg->front.iov_base;
1549			head->num = cpu_to_le32(0);
1550			msg->front.iov_len = sizeof(*head);
 
 
 
1551		}
 
1552		cap = list_first_entry(&tmp_list, struct ceph_cap,
1553					session_caps);
1554		list_del(&cap->session_caps);
1555		num_cap_releases--;
1556
1557		head = msg->front.iov_base;
1558		le32_add_cpu(&head->num, 1);
 
1559		item = msg->front.iov_base + msg->front.iov_len;
1560		item->ino = cpu_to_le64(cap->cap_ino);
1561		item->cap_id = cpu_to_le64(cap->cap_id);
1562		item->migrate_seq = cpu_to_le32(cap->mseq);
1563		item->seq = cpu_to_le32(cap->issue_seq);
1564		msg->front.iov_len += sizeof(*item);
1565
1566		ceph_put_cap(mdsc, cap);
1567
1568		if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
 
 
 
 
 
1569			msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1570			dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1571			ceph_con_send(&session->s_con, msg);
1572			msg = NULL;
1573		}
1574	}
1575
1576	BUG_ON(num_cap_releases != 0);
1577
1578	spin_lock(&session->s_cap_lock);
1579	if (!list_empty(&session->s_cap_releases))
1580		goto again;
1581	spin_unlock(&session->s_cap_lock);
1582
1583	if (msg) {
 
 
 
 
 
1584		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1585		dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1586		ceph_con_send(&session->s_con, msg);
1587	}
1588	return;
1589out_err:
1590	pr_err("send_cap_releases mds%d, failed to allocate message\n",
1591		session->s_mds);
1592	spin_lock(&session->s_cap_lock);
1593	list_splice(&tmp_list, &session->s_cap_releases);
1594	session->s_num_cap_releases += num_cap_releases;
1595	spin_unlock(&session->s_cap_lock);
1596}
1597
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1598/*
1599 * requests
1600 */
1601
1602int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1603				    struct inode *dir)
1604{
1605	struct ceph_inode_info *ci = ceph_inode(dir);
1606	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1607	struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1608	size_t size = sizeof(struct ceph_mds_reply_dir_entry);
1609	int order, num_entries;
1610
1611	spin_lock(&ci->i_ceph_lock);
1612	num_entries = ci->i_files + ci->i_subdirs;
1613	spin_unlock(&ci->i_ceph_lock);
1614	num_entries = max(num_entries, 1);
1615	num_entries = min(num_entries, opt->max_readdir);
1616
1617	order = get_order(size * num_entries);
1618	while (order >= 0) {
1619		rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
1620							     __GFP_NOWARN,
1621							     order);
1622		if (rinfo->dir_entries)
1623			break;
1624		order--;
1625	}
1626	if (!rinfo->dir_entries)
1627		return -ENOMEM;
1628
1629	num_entries = (PAGE_SIZE << order) / size;
1630	num_entries = min(num_entries, opt->max_readdir);
1631
1632	rinfo->dir_buf_size = PAGE_SIZE << order;
1633	req->r_num_caps = num_entries + 1;
1634	req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1635	req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1636	return 0;
1637}
1638
1639/*
1640 * Create an mds request.
1641 */
1642struct ceph_mds_request *
1643ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1644{
1645	struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
 
1646
1647	if (!req)
1648		return ERR_PTR(-ENOMEM);
1649
1650	mutex_init(&req->r_fill_mutex);
1651	req->r_mdsc = mdsc;
1652	req->r_started = jiffies;
1653	req->r_resend_mds = -1;
1654	INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1655	INIT_LIST_HEAD(&req->r_unsafe_target_item);
1656	req->r_fmode = -1;
1657	kref_init(&req->r_kref);
1658	RB_CLEAR_NODE(&req->r_node);
1659	INIT_LIST_HEAD(&req->r_wait);
1660	init_completion(&req->r_completion);
1661	init_completion(&req->r_safe_completion);
1662	INIT_LIST_HEAD(&req->r_unsafe_item);
1663
1664	req->r_stamp = current_fs_time(mdsc->fsc->sb);
 
1665
1666	req->r_op = op;
1667	req->r_direct_mode = mode;
1668	return req;
1669}
1670
1671/*
1672 * return oldest (lowest) request, tid in request tree, 0 if none.
1673 *
1674 * called under mdsc->mutex.
1675 */
1676static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1677{
1678	if (RB_EMPTY_ROOT(&mdsc->request_tree))
1679		return NULL;
1680	return rb_entry(rb_first(&mdsc->request_tree),
1681			struct ceph_mds_request, r_node);
1682}
1683
1684static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1685{
1686	return mdsc->oldest_tid;
1687}
1688
1689/*
1690 * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1691 * on build_path_from_dentry in fs/cifs/dir.c.
1692 *
1693 * If @stop_on_nosnap, generate path relative to the first non-snapped
1694 * inode.
1695 *
1696 * Encode hidden .snap dirs as a double /, i.e.
1697 *   foo/.snap/bar -> foo//bar
1698 */
1699char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1700			   int stop_on_nosnap)
1701{
1702	struct dentry *temp;
1703	char *path;
1704	int len, pos;
1705	unsigned seq;
 
1706
1707	if (dentry == NULL)
1708		return ERR_PTR(-EINVAL);
1709
 
 
 
1710retry:
1711	len = 0;
 
 
1712	seq = read_seqbegin(&rename_lock);
1713	rcu_read_lock();
1714	for (temp = dentry; !IS_ROOT(temp);) {
1715		struct inode *inode = d_inode(temp);
1716		if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1717			len++;  /* slash only */
1718		else if (stop_on_nosnap && inode &&
1719			 ceph_snap(inode) == CEPH_NOSNAP)
1720			break;
1721		else
1722			len += 1 + temp->d_name.len;
1723		temp = temp->d_parent;
1724	}
1725	rcu_read_unlock();
1726	if (len)
1727		len--;  /* no leading '/' */
1728
1729	path = kmalloc(len+1, GFP_NOFS);
1730	if (path == NULL)
1731		return ERR_PTR(-ENOMEM);
1732	pos = len;
1733	path[pos] = 0;	/* trailing null */
1734	rcu_read_lock();
1735	for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1736		struct inode *inode;
1737
1738		spin_lock(&temp->d_lock);
1739		inode = d_inode(temp);
1740		if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1741			dout("build_path path+%d: %p SNAPDIR\n",
1742			     pos, temp);
1743		} else if (stop_on_nosnap && inode &&
1744			   ceph_snap(inode) == CEPH_NOSNAP) {
1745			spin_unlock(&temp->d_lock);
 
1746			break;
1747		} else {
1748			pos -= temp->d_name.len;
1749			if (pos < 0) {
1750				spin_unlock(&temp->d_lock);
1751				break;
1752			}
1753			strncpy(path + pos, temp->d_name.name,
1754				temp->d_name.len);
1755		}
1756		spin_unlock(&temp->d_lock);
1757		if (pos)
1758			path[--pos] = '/';
1759		temp = temp->d_parent;
 
 
 
 
 
 
 
 
1760	}
 
1761	rcu_read_unlock();
1762	if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1763		pr_err("build_path did not end path lookup where "
1764		       "expected, namelen is %d, pos is %d\n", len, pos);
1765		/* presumably this is only possible if racing with a
1766		   rename of one of the parent directories (we can not
1767		   lock the dentries above us to prevent this, but
1768		   retrying should be harmless) */
1769		kfree(path);
1770		goto retry;
1771	}
1772
1773	*base = ceph_ino(d_inode(temp));
1774	*plen = len;
1775	dout("build_path on %p %d built %llx '%.*s'\n",
1776	     dentry, d_count(dentry), *base, len, path);
1777	return path;
1778}
1779
1780static int build_dentry_path(struct dentry *dentry,
1781			     const char **ppath, int *ppathlen, u64 *pino,
1782			     int *pfreepath)
1783{
1784	char *path;
1785
1786	if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1787		*pino = ceph_ino(d_inode(dentry->d_parent));
 
 
 
 
1788		*ppath = dentry->d_name.name;
1789		*ppathlen = dentry->d_name.len;
1790		return 0;
1791	}
 
1792	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1793	if (IS_ERR(path))
1794		return PTR_ERR(path);
1795	*ppath = path;
1796	*pfreepath = 1;
1797	return 0;
1798}
1799
1800static int build_inode_path(struct inode *inode,
1801			    const char **ppath, int *ppathlen, u64 *pino,
1802			    int *pfreepath)
1803{
1804	struct dentry *dentry;
1805	char *path;
1806
1807	if (ceph_snap(inode) == CEPH_NOSNAP) {
1808		*pino = ceph_ino(inode);
1809		*ppathlen = 0;
1810		return 0;
1811	}
1812	dentry = d_find_alias(inode);
1813	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1814	dput(dentry);
1815	if (IS_ERR(path))
1816		return PTR_ERR(path);
1817	*ppath = path;
1818	*pfreepath = 1;
1819	return 0;
1820}
1821
1822/*
1823 * request arguments may be specified via an inode *, a dentry *, or
1824 * an explicit ino+path.
1825 */
1826static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1827				  const char *rpath, u64 rino,
1828				  const char **ppath, int *pathlen,
1829				  u64 *ino, int *freepath)
1830{
1831	int r = 0;
1832
1833	if (rinode) {
1834		r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1835		dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1836		     ceph_snap(rinode));
1837	} else if (rdentry) {
1838		r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
 
1839		dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1840		     *ppath);
1841	} else if (rpath || rino) {
1842		*ino = rino;
1843		*ppath = rpath;
1844		*pathlen = rpath ? strlen(rpath) : 0;
1845		dout(" path %.*s\n", *pathlen, rpath);
1846	}
1847
1848	return r;
1849}
1850
1851/*
1852 * called under mdsc->mutex
1853 */
1854static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1855					       struct ceph_mds_request *req,
1856					       int mds, bool drop_cap_releases)
1857{
1858	struct ceph_msg *msg;
1859	struct ceph_mds_request_head *head;
1860	const char *path1 = NULL;
1861	const char *path2 = NULL;
1862	u64 ino1 = 0, ino2 = 0;
1863	int pathlen1 = 0, pathlen2 = 0;
1864	int freepath1 = 0, freepath2 = 0;
1865	int len;
1866	u16 releases;
1867	void *p, *end;
1868	int ret;
1869
1870	ret = set_request_path_attr(req->r_inode, req->r_dentry,
1871			      req->r_path1, req->r_ino1.ino,
1872			      &path1, &pathlen1, &ino1, &freepath1);
 
 
1873	if (ret < 0) {
1874		msg = ERR_PTR(ret);
1875		goto out;
1876	}
1877
 
1878	ret = set_request_path_attr(NULL, req->r_old_dentry,
 
1879			      req->r_path2, req->r_ino2.ino,
1880			      &path2, &pathlen2, &ino2, &freepath2);
1881	if (ret < 0) {
1882		msg = ERR_PTR(ret);
1883		goto out_free1;
1884	}
1885
1886	len = sizeof(*head) +
1887		pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1888		sizeof(struct ceph_timespec);
1889
1890	/* calculate (max) length for cap releases */
1891	len += sizeof(struct ceph_mds_request_release) *
1892		(!!req->r_inode_drop + !!req->r_dentry_drop +
1893		 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1894	if (req->r_dentry_drop)
1895		len += req->r_dentry->d_name.len;
1896	if (req->r_old_dentry_drop)
1897		len += req->r_old_dentry->d_name.len;
1898
1899	msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1900	if (!msg) {
1901		msg = ERR_PTR(-ENOMEM);
1902		goto out_free2;
1903	}
1904
1905	msg->hdr.version = cpu_to_le16(2);
1906	msg->hdr.tid = cpu_to_le64(req->r_tid);
1907
1908	head = msg->front.iov_base;
1909	p = msg->front.iov_base + sizeof(*head);
1910	end = msg->front.iov_base + msg->front.iov_len;
1911
1912	head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1913	head->op = cpu_to_le32(req->r_op);
1914	head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1915	head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1916	head->args = req->r_args;
1917
1918	ceph_encode_filepath(&p, end, ino1, path1);
1919	ceph_encode_filepath(&p, end, ino2, path2);
1920
1921	/* make note of release offset, in case we need to replay */
1922	req->r_request_release_offset = p - msg->front.iov_base;
1923
1924	/* cap releases */
1925	releases = 0;
1926	if (req->r_inode_drop)
1927		releases += ceph_encode_inode_release(&p,
1928		      req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1929		      mds, req->r_inode_drop, req->r_inode_unless, 0);
1930	if (req->r_dentry_drop)
1931		releases += ceph_encode_dentry_release(&p, req->r_dentry,
1932		       mds, req->r_dentry_drop, req->r_dentry_unless);
 
1933	if (req->r_old_dentry_drop)
1934		releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1935		       mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
 
 
1936	if (req->r_old_inode_drop)
1937		releases += ceph_encode_inode_release(&p,
1938		      d_inode(req->r_old_dentry),
1939		      mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1940
1941	if (drop_cap_releases) {
1942		releases = 0;
1943		p = msg->front.iov_base + req->r_request_release_offset;
1944	}
1945
1946	head->num_releases = cpu_to_le16(releases);
1947
1948	/* time stamp */
1949	{
1950		struct ceph_timespec ts;
1951		ceph_encode_timespec(&ts, &req->r_stamp);
1952		ceph_encode_copy(&p, &ts, sizeof(ts));
1953	}
1954
1955	BUG_ON(p > end);
1956	msg->front.iov_len = p - msg->front.iov_base;
1957	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1958
1959	if (req->r_pagelist) {
1960		struct ceph_pagelist *pagelist = req->r_pagelist;
1961		atomic_inc(&pagelist->refcnt);
1962		ceph_msg_data_add_pagelist(msg, pagelist);
1963		msg->hdr.data_len = cpu_to_le32(pagelist->length);
1964	} else {
1965		msg->hdr.data_len = 0;
1966	}
1967
1968	msg->hdr.data_off = cpu_to_le16(0);
1969
1970out_free2:
1971	if (freepath2)
1972		kfree((char *)path2);
1973out_free1:
1974	if (freepath1)
1975		kfree((char *)path1);
1976out:
1977	return msg;
1978}
1979
1980/*
1981 * called under mdsc->mutex if error, under no mutex if
1982 * success.
1983 */
1984static void complete_request(struct ceph_mds_client *mdsc,
1985			     struct ceph_mds_request *req)
1986{
1987	if (req->r_callback)
1988		req->r_callback(mdsc, req);
1989	else
1990		complete_all(&req->r_completion);
1991}
1992
1993/*
1994 * called under mdsc->mutex
1995 */
1996static int __prepare_send_request(struct ceph_mds_client *mdsc,
1997				  struct ceph_mds_request *req,
1998				  int mds, bool drop_cap_releases)
1999{
2000	struct ceph_mds_request_head *rhead;
2001	struct ceph_msg *msg;
2002	int flags = 0;
2003
2004	req->r_attempts++;
2005	if (req->r_inode) {
2006		struct ceph_cap *cap =
2007			ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2008
2009		if (cap)
2010			req->r_sent_on_mseq = cap->mseq;
2011		else
2012			req->r_sent_on_mseq = -1;
2013	}
2014	dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2015	     req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2016
2017	if (req->r_got_unsafe) {
2018		void *p;
2019		/*
2020		 * Replay.  Do not regenerate message (and rebuild
2021		 * paths, etc.); just use the original message.
2022		 * Rebuilding paths will break for renames because
2023		 * d_move mangles the src name.
2024		 */
2025		msg = req->r_request;
2026		rhead = msg->front.iov_base;
2027
2028		flags = le32_to_cpu(rhead->flags);
2029		flags |= CEPH_MDS_FLAG_REPLAY;
2030		rhead->flags = cpu_to_le32(flags);
2031
2032		if (req->r_target_inode)
2033			rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2034
2035		rhead->num_retry = req->r_attempts - 1;
2036
2037		/* remove cap/dentry releases from message */
2038		rhead->num_releases = 0;
2039
2040		/* time stamp */
2041		p = msg->front.iov_base + req->r_request_release_offset;
2042		{
2043			struct ceph_timespec ts;
2044			ceph_encode_timespec(&ts, &req->r_stamp);
2045			ceph_encode_copy(&p, &ts, sizeof(ts));
2046		}
2047
2048		msg->front.iov_len = p - msg->front.iov_base;
2049		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2050		return 0;
2051	}
2052
2053	if (req->r_request) {
2054		ceph_msg_put(req->r_request);
2055		req->r_request = NULL;
2056	}
2057	msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2058	if (IS_ERR(msg)) {
2059		req->r_err = PTR_ERR(msg);
2060		return PTR_ERR(msg);
2061	}
2062	req->r_request = msg;
2063
2064	rhead = msg->front.iov_base;
2065	rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2066	if (req->r_got_unsafe)
2067		flags |= CEPH_MDS_FLAG_REPLAY;
2068	if (req->r_locked_dir)
2069		flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2070	rhead->flags = cpu_to_le32(flags);
2071	rhead->num_fwd = req->r_num_fwd;
2072	rhead->num_retry = req->r_attempts - 1;
2073	rhead->ino = 0;
2074
2075	dout(" r_locked_dir = %p\n", req->r_locked_dir);
2076	return 0;
2077}
2078
2079/*
2080 * send request, or put it on the appropriate wait list.
2081 */
2082static int __do_request(struct ceph_mds_client *mdsc,
2083			struct ceph_mds_request *req)
2084{
2085	struct ceph_mds_session *session = NULL;
2086	int mds = -1;
2087	int err = 0;
2088
2089	if (req->r_err || req->r_got_result) {
2090		if (req->r_aborted)
2091			__unregister_request(mdsc, req);
2092		goto out;
2093	}
2094
2095	if (req->r_timeout &&
2096	    time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2097		dout("do_request timed out\n");
2098		err = -EIO;
2099		goto finish;
2100	}
2101	if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2102		dout("do_request forced umount\n");
2103		err = -EIO;
2104		goto finish;
2105	}
2106	if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2107		if (mdsc->mdsmap_err) {
2108			err = mdsc->mdsmap_err;
2109			dout("do_request mdsmap err %d\n", err);
2110			goto finish;
2111		}
2112		if (mdsc->mdsmap->m_epoch == 0) {
2113			dout("do_request no mdsmap, waiting for map\n");
2114			list_add(&req->r_wait, &mdsc->waiting_for_map);
2115			goto finish;
2116		}
2117		if (!(mdsc->fsc->mount_options->flags &
2118		      CEPH_MOUNT_OPT_MOUNTWAIT) &&
2119		    !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2120			err = -ENOENT;
2121			pr_info("probably no mds server is up\n");
2122			goto finish;
2123		}
2124	}
2125
2126	put_request_session(req);
2127
2128	mds = __choose_mds(mdsc, req);
2129	if (mds < 0 ||
2130	    ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2131		dout("do_request no mds or not active, waiting for map\n");
2132		list_add(&req->r_wait, &mdsc->waiting_for_map);
2133		goto out;
2134	}
2135
2136	/* get, open session */
2137	session = __ceph_lookup_mds_session(mdsc, mds);
2138	if (!session) {
2139		session = register_session(mdsc, mds);
2140		if (IS_ERR(session)) {
2141			err = PTR_ERR(session);
2142			goto finish;
2143		}
2144	}
2145	req->r_session = get_session(session);
2146
2147	dout("do_request mds%d session %p state %s\n", mds, session,
2148	     ceph_session_state_name(session->s_state));
2149	if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2150	    session->s_state != CEPH_MDS_SESSION_HUNG) {
2151		if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2152			err = -EACCES;
2153			goto out_session;
2154		}
2155		if (session->s_state == CEPH_MDS_SESSION_NEW ||
2156		    session->s_state == CEPH_MDS_SESSION_CLOSING)
2157			__open_session(mdsc, session);
2158		list_add(&req->r_wait, &session->s_waiting);
2159		goto out_session;
2160	}
2161
2162	/* send request */
2163	req->r_resend_mds = -1;   /* forget any previous mds hint */
2164
2165	if (req->r_request_started == 0)   /* note request start time */
2166		req->r_request_started = jiffies;
2167
2168	err = __prepare_send_request(mdsc, req, mds, false);
2169	if (!err) {
2170		ceph_msg_get(req->r_request);
2171		ceph_con_send(&session->s_con, req->r_request);
2172	}
2173
2174out_session:
2175	ceph_put_mds_session(session);
2176finish:
2177	if (err) {
2178		dout("__do_request early error %d\n", err);
2179		req->r_err = err;
2180		complete_request(mdsc, req);
2181		__unregister_request(mdsc, req);
2182	}
2183out:
2184	return err;
2185}
2186
2187/*
2188 * called under mdsc->mutex
2189 */
2190static void __wake_requests(struct ceph_mds_client *mdsc,
2191			    struct list_head *head)
2192{
2193	struct ceph_mds_request *req;
2194	LIST_HEAD(tmp_list);
2195
2196	list_splice_init(head, &tmp_list);
2197
2198	while (!list_empty(&tmp_list)) {
2199		req = list_entry(tmp_list.next,
2200				 struct ceph_mds_request, r_wait);
2201		list_del_init(&req->r_wait);
2202		dout(" wake request %p tid %llu\n", req, req->r_tid);
2203		__do_request(mdsc, req);
2204	}
2205}
2206
2207/*
2208 * Wake up threads with requests pending for @mds, so that they can
2209 * resubmit their requests to a possibly different mds.
2210 */
2211static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2212{
2213	struct ceph_mds_request *req;
2214	struct rb_node *p = rb_first(&mdsc->request_tree);
2215
2216	dout("kick_requests mds%d\n", mds);
2217	while (p) {
2218		req = rb_entry(p, struct ceph_mds_request, r_node);
2219		p = rb_next(p);
2220		if (req->r_got_unsafe)
2221			continue;
2222		if (req->r_attempts > 0)
2223			continue; /* only new requests */
2224		if (req->r_session &&
2225		    req->r_session->s_mds == mds) {
2226			dout(" kicking tid %llu\n", req->r_tid);
2227			list_del_init(&req->r_wait);
2228			__do_request(mdsc, req);
2229		}
2230	}
2231}
2232
2233void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2234			      struct ceph_mds_request *req)
2235{
2236	dout("submit_request on %p\n", req);
2237	mutex_lock(&mdsc->mutex);
2238	__register_request(mdsc, req, NULL);
2239	__do_request(mdsc, req);
2240	mutex_unlock(&mdsc->mutex);
2241}
2242
2243/*
2244 * Synchrously perform an mds request.  Take care of all of the
2245 * session setup, forwarding, retry details.
2246 */
2247int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2248			 struct inode *dir,
2249			 struct ceph_mds_request *req)
2250{
2251	int err;
2252
2253	dout("do_request on %p\n", req);
2254
2255	/* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2256	if (req->r_inode)
2257		ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2258	if (req->r_locked_dir)
2259		ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2260	if (req->r_old_dentry_dir)
2261		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2262				  CEPH_CAP_PIN);
2263
2264	/* issue */
2265	mutex_lock(&mdsc->mutex);
2266	__register_request(mdsc, req, dir);
2267	__do_request(mdsc, req);
 
 
 
 
2268
2269	if (req->r_err) {
2270		err = req->r_err;
2271		goto out;
2272	}
2273
2274	/* wait */
2275	mutex_unlock(&mdsc->mutex);
2276	dout("do_request waiting\n");
2277	if (!req->r_timeout && req->r_wait_for_completion) {
2278		err = req->r_wait_for_completion(mdsc, req);
2279	} else {
2280		long timeleft = wait_for_completion_killable_timeout(
2281					&req->r_completion,
2282					ceph_timeout_jiffies(req->r_timeout));
2283		if (timeleft > 0)
2284			err = 0;
2285		else if (!timeleft)
2286			err = -EIO;  /* timed out */
2287		else
2288			err = timeleft;  /* killed */
2289	}
2290	dout("do_request waited, got %d\n", err);
2291	mutex_lock(&mdsc->mutex);
2292
2293	/* only abort if we didn't race with a real reply */
2294	if (req->r_got_result) {
2295		err = le32_to_cpu(req->r_reply_info.head->result);
2296	} else if (err < 0) {
2297		dout("aborted request %lld with %d\n", req->r_tid, err);
2298
2299		/*
2300		 * ensure we aren't running concurrently with
2301		 * ceph_fill_trace or ceph_readdir_prepopulate, which
2302		 * rely on locks (dir mutex) held by our caller.
2303		 */
2304		mutex_lock(&req->r_fill_mutex);
2305		req->r_err = err;
2306		req->r_aborted = true;
2307		mutex_unlock(&req->r_fill_mutex);
2308
2309		if (req->r_locked_dir &&
2310		    (req->r_op & CEPH_MDS_OP_WRITE))
2311			ceph_invalidate_dir_request(req);
2312	} else {
2313		err = req->r_err;
2314	}
2315
2316out:
2317	mutex_unlock(&mdsc->mutex);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2318	dout("do_request %p done, result %d\n", req, err);
2319	return err;
2320}
2321
2322/*
2323 * Invalidate dir's completeness, dentry lease state on an aborted MDS
2324 * namespace request.
2325 */
2326void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2327{
2328	struct inode *inode = req->r_locked_dir;
 
2329
2330	dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2331
2332	ceph_dir_clear_complete(inode);
 
 
2333	if (req->r_dentry)
2334		ceph_invalidate_dentry_lease(req->r_dentry);
2335	if (req->r_old_dentry)
2336		ceph_invalidate_dentry_lease(req->r_old_dentry);
2337}
2338
2339/*
2340 * Handle mds reply.
2341 *
2342 * We take the session mutex and parse and process the reply immediately.
2343 * This preserves the logical ordering of replies, capabilities, etc., sent
2344 * by the MDS as they are applied to our local cache.
2345 */
2346static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2347{
2348	struct ceph_mds_client *mdsc = session->s_mdsc;
2349	struct ceph_mds_request *req;
2350	struct ceph_mds_reply_head *head = msg->front.iov_base;
2351	struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2352	struct ceph_snap_realm *realm;
2353	u64 tid;
2354	int err, result;
2355	int mds = session->s_mds;
2356
2357	if (msg->front.iov_len < sizeof(*head)) {
2358		pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2359		ceph_msg_dump(msg);
2360		return;
2361	}
2362
2363	/* get request, session */
2364	tid = le64_to_cpu(msg->hdr.tid);
2365	mutex_lock(&mdsc->mutex);
2366	req = lookup_get_request(mdsc, tid);
2367	if (!req) {
2368		dout("handle_reply on unknown tid %llu\n", tid);
2369		mutex_unlock(&mdsc->mutex);
2370		return;
2371	}
2372	dout("handle_reply %p\n", req);
2373
2374	/* correct session? */
2375	if (req->r_session != session) {
2376		pr_err("mdsc_handle_reply got %llu on session mds%d"
2377		       " not mds%d\n", tid, session->s_mds,
2378		       req->r_session ? req->r_session->s_mds : -1);
2379		mutex_unlock(&mdsc->mutex);
2380		goto out;
2381	}
2382
2383	/* dup? */
2384	if ((req->r_got_unsafe && !head->safe) ||
2385	    (req->r_got_safe && head->safe)) {
2386		pr_warn("got a dup %s reply on %llu from mds%d\n",
2387			   head->safe ? "safe" : "unsafe", tid, mds);
2388		mutex_unlock(&mdsc->mutex);
2389		goto out;
2390	}
2391	if (req->r_got_safe) {
2392		pr_warn("got unsafe after safe on %llu from mds%d\n",
2393			   tid, mds);
2394		mutex_unlock(&mdsc->mutex);
2395		goto out;
2396	}
2397
2398	result = le32_to_cpu(head->result);
2399
2400	/*
2401	 * Handle an ESTALE
2402	 * if we're not talking to the authority, send to them
2403	 * if the authority has changed while we weren't looking,
2404	 * send to new authority
2405	 * Otherwise we just have to return an ESTALE
2406	 */
2407	if (result == -ESTALE) {
2408		dout("got ESTALE on request %llu", req->r_tid);
2409		req->r_resend_mds = -1;
2410		if (req->r_direct_mode != USE_AUTH_MDS) {
2411			dout("not using auth, setting for that now");
2412			req->r_direct_mode = USE_AUTH_MDS;
2413			__do_request(mdsc, req);
2414			mutex_unlock(&mdsc->mutex);
2415			goto out;
2416		} else  {
2417			int mds = __choose_mds(mdsc, req);
2418			if (mds >= 0 && mds != req->r_session->s_mds) {
2419				dout("but auth changed, so resending");
2420				__do_request(mdsc, req);
2421				mutex_unlock(&mdsc->mutex);
2422				goto out;
2423			}
2424		}
2425		dout("have to return ESTALE on request %llu", req->r_tid);
2426	}
2427
2428
2429	if (head->safe) {
2430		req->r_got_safe = true;
2431		__unregister_request(mdsc, req);
2432
2433		if (req->r_got_unsafe) {
2434			/*
2435			 * We already handled the unsafe response, now do the
2436			 * cleanup.  No need to examine the response; the MDS
2437			 * doesn't include any result info in the safe
2438			 * response.  And even if it did, there is nothing
2439			 * useful we could do with a revised return value.
2440			 */
2441			dout("got safe reply %llu, mds%d\n", tid, mds);
2442
2443			/* last unsafe request during umount? */
2444			if (mdsc->stopping && !__get_oldest_req(mdsc))
2445				complete_all(&mdsc->safe_umount_waiters);
2446			mutex_unlock(&mdsc->mutex);
2447			goto out;
2448		}
2449	} else {
2450		req->r_got_unsafe = true;
2451		list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2452		if (req->r_unsafe_dir) {
2453			struct ceph_inode_info *ci =
2454					ceph_inode(req->r_unsafe_dir);
2455			spin_lock(&ci->i_unsafe_lock);
2456			list_add_tail(&req->r_unsafe_dir_item,
2457				      &ci->i_unsafe_dirops);
2458			spin_unlock(&ci->i_unsafe_lock);
2459		}
2460	}
2461
2462	dout("handle_reply tid %lld result %d\n", tid, result);
2463	rinfo = &req->r_reply_info;
2464	err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
 
 
 
2465	mutex_unlock(&mdsc->mutex);
2466
2467	mutex_lock(&session->s_mutex);
2468	if (err < 0) {
2469		pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2470		ceph_msg_dump(msg);
2471		goto out_err;
2472	}
2473
2474	/* snap trace */
2475	realm = NULL;
2476	if (rinfo->snapblob_len) {
2477		down_write(&mdsc->snap_rwsem);
2478		ceph_update_snap_trace(mdsc, rinfo->snapblob,
2479				rinfo->snapblob + rinfo->snapblob_len,
2480				le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2481				&realm);
2482		downgrade_write(&mdsc->snap_rwsem);
2483	} else {
2484		down_read(&mdsc->snap_rwsem);
2485	}
2486
2487	/* insert trace into our cache */
2488	mutex_lock(&req->r_fill_mutex);
2489	current->journal_info = req;
2490	err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2491	if (err == 0) {
2492		if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2493				    req->r_op == CEPH_MDS_OP_LSSNAP))
2494			ceph_readdir_prepopulate(req, req->r_session);
2495		ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2496	}
2497	current->journal_info = NULL;
2498	mutex_unlock(&req->r_fill_mutex);
2499
2500	up_read(&mdsc->snap_rwsem);
2501	if (realm)
2502		ceph_put_snap_realm(mdsc, realm);
2503
2504	if (err == 0 && req->r_got_unsafe && req->r_target_inode) {
2505		struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
2506		spin_lock(&ci->i_unsafe_lock);
2507		list_add_tail(&req->r_unsafe_target_item, &ci->i_unsafe_iops);
2508		spin_unlock(&ci->i_unsafe_lock);
 
 
 
 
 
 
 
2509	}
2510out_err:
2511	mutex_lock(&mdsc->mutex);
2512	if (!req->r_aborted) {
2513		if (err) {
2514			req->r_err = err;
2515		} else {
2516			req->r_reply =  ceph_msg_get(msg);
2517			req->r_got_result = true;
2518		}
2519	} else {
2520		dout("reply arrived after request %lld was aborted\n", tid);
2521	}
2522	mutex_unlock(&mdsc->mutex);
2523
2524	mutex_unlock(&session->s_mutex);
2525
2526	/* kick calling process */
2527	complete_request(mdsc, req);
2528out:
2529	ceph_mdsc_put_request(req);
2530	return;
2531}
2532
2533
2534
2535/*
2536 * handle mds notification that our request has been forwarded.
2537 */
2538static void handle_forward(struct ceph_mds_client *mdsc,
2539			   struct ceph_mds_session *session,
2540			   struct ceph_msg *msg)
2541{
2542	struct ceph_mds_request *req;
2543	u64 tid = le64_to_cpu(msg->hdr.tid);
2544	u32 next_mds;
2545	u32 fwd_seq;
2546	int err = -EINVAL;
2547	void *p = msg->front.iov_base;
2548	void *end = p + msg->front.iov_len;
2549
2550	ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2551	next_mds = ceph_decode_32(&p);
2552	fwd_seq = ceph_decode_32(&p);
2553
2554	mutex_lock(&mdsc->mutex);
2555	req = lookup_get_request(mdsc, tid);
2556	if (!req) {
2557		dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2558		goto out;  /* dup reply? */
2559	}
2560
2561	if (req->r_aborted) {
2562		dout("forward tid %llu aborted, unregistering\n", tid);
2563		__unregister_request(mdsc, req);
2564	} else if (fwd_seq <= req->r_num_fwd) {
2565		dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2566		     tid, next_mds, req->r_num_fwd, fwd_seq);
2567	} else {
2568		/* resend. forward race not possible; mds would drop */
2569		dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2570		BUG_ON(req->r_err);
2571		BUG_ON(req->r_got_result);
2572		req->r_attempts = 0;
2573		req->r_num_fwd = fwd_seq;
2574		req->r_resend_mds = next_mds;
2575		put_request_session(req);
2576		__do_request(mdsc, req);
2577	}
2578	ceph_mdsc_put_request(req);
2579out:
2580	mutex_unlock(&mdsc->mutex);
2581	return;
2582
2583bad:
2584	pr_err("mdsc_handle_forward decode error err=%d\n", err);
2585}
2586
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2587/*
2588 * handle a mds session control message
2589 */
2590static void handle_session(struct ceph_mds_session *session,
2591			   struct ceph_msg *msg)
2592{
2593	struct ceph_mds_client *mdsc = session->s_mdsc;
 
 
 
 
 
2594	u32 op;
2595	u64 seq;
2596	int mds = session->s_mds;
2597	struct ceph_mds_session_head *h = msg->front.iov_base;
2598	int wake = 0;
 
2599
2600	/* decode */
2601	if (msg->front.iov_len != sizeof(*h))
2602		goto bad;
 
 
2603	op = le32_to_cpu(h->op);
2604	seq = le64_to_cpu(h->seq);
2605
 
 
 
 
 
 
 
 
 
 
 
 
2606	mutex_lock(&mdsc->mutex);
2607	if (op == CEPH_SESSION_CLOSE)
 
2608		__unregister_session(mdsc, session);
 
2609	/* FIXME: this ttl calculation is generous */
2610	session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2611	mutex_unlock(&mdsc->mutex);
2612
2613	mutex_lock(&session->s_mutex);
2614
2615	dout("handle_session mds%d %s %p state %s seq %llu\n",
2616	     mds, ceph_session_op_name(op), session,
2617	     ceph_session_state_name(session->s_state), seq);
2618
2619	if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2620		session->s_state = CEPH_MDS_SESSION_OPEN;
2621		pr_info("mds%d came back\n", session->s_mds);
2622	}
2623
2624	switch (op) {
2625	case CEPH_SESSION_OPEN:
2626		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2627			pr_info("mds%d reconnect success\n", session->s_mds);
2628		session->s_state = CEPH_MDS_SESSION_OPEN;
 
2629		renewed_caps(mdsc, session, 0);
2630		wake = 1;
2631		if (mdsc->stopping)
2632			__close_session(mdsc, session);
2633		break;
2634
2635	case CEPH_SESSION_RENEWCAPS:
2636		if (session->s_renew_seq == seq)
2637			renewed_caps(mdsc, session, 1);
2638		break;
2639
2640	case CEPH_SESSION_CLOSE:
2641		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2642			pr_info("mds%d reconnect denied\n", session->s_mds);
2643		cleanup_session_requests(mdsc, session);
2644		remove_session_caps(session);
2645		wake = 2; /* for good measure */
2646		wake_up_all(&mdsc->session_close_wq);
2647		break;
2648
2649	case CEPH_SESSION_STALE:
2650		pr_info("mds%d caps went stale, renewing\n",
2651			session->s_mds);
2652		spin_lock(&session->s_gen_ttl_lock);
2653		session->s_cap_gen++;
2654		session->s_cap_ttl = jiffies - 1;
2655		spin_unlock(&session->s_gen_ttl_lock);
2656		send_renew_caps(mdsc, session);
2657		break;
2658
2659	case CEPH_SESSION_RECALL_STATE:
2660		trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2661		break;
2662
2663	case CEPH_SESSION_FLUSHMSG:
2664		send_flushmsg_ack(mdsc, session, seq);
2665		break;
2666
2667	case CEPH_SESSION_FORCE_RO:
2668		dout("force_session_readonly %p\n", session);
2669		spin_lock(&session->s_cap_lock);
2670		session->s_readonly = true;
2671		spin_unlock(&session->s_cap_lock);
2672		wake_up_session_caps(session, 0);
2673		break;
2674
2675	case CEPH_SESSION_REJECT:
2676		WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
2677		pr_info("mds%d rejected session\n", session->s_mds);
2678		session->s_state = CEPH_MDS_SESSION_REJECTED;
2679		cleanup_session_requests(mdsc, session);
2680		remove_session_caps(session);
 
 
2681		wake = 2; /* for good measure */
2682		break;
2683
2684	default:
2685		pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2686		WARN_ON(1);
2687	}
2688
2689	mutex_unlock(&session->s_mutex);
2690	if (wake) {
2691		mutex_lock(&mdsc->mutex);
2692		__wake_requests(mdsc, &session->s_waiting);
2693		if (wake == 2)
2694			kick_requests(mdsc, mds);
2695		mutex_unlock(&mdsc->mutex);
2696	}
 
 
2697	return;
2698
2699bad:
2700	pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2701	       (int)msg->front.iov_len);
2702	ceph_msg_dump(msg);
2703	return;
2704}
2705
2706
2707/*
2708 * called under session->mutex.
2709 */
2710static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2711				   struct ceph_mds_session *session)
2712{
2713	struct ceph_mds_request *req, *nreq;
2714	struct rb_node *p;
2715	int err;
2716
2717	dout("replay_unsafe_requests mds%d\n", session->s_mds);
2718
2719	mutex_lock(&mdsc->mutex);
2720	list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2721		err = __prepare_send_request(mdsc, req, session->s_mds, true);
2722		if (!err) {
2723			ceph_msg_get(req->r_request);
2724			ceph_con_send(&session->s_con, req->r_request);
2725		}
2726	}
2727
2728	/*
2729	 * also re-send old requests when MDS enters reconnect stage. So that MDS
2730	 * can process completed request in clientreplay stage.
2731	 */
2732	p = rb_first(&mdsc->request_tree);
2733	while (p) {
2734		req = rb_entry(p, struct ceph_mds_request, r_node);
2735		p = rb_next(p);
2736		if (req->r_got_unsafe)
2737			continue;
2738		if (req->r_attempts == 0)
2739			continue; /* only old requests */
2740		if (req->r_session &&
2741		    req->r_session->s_mds == session->s_mds) {
2742			err = __prepare_send_request(mdsc, req,
2743						     session->s_mds, true);
2744			if (!err) {
2745				ceph_msg_get(req->r_request);
2746				ceph_con_send(&session->s_con, req->r_request);
2747			}
2748		}
2749	}
2750	mutex_unlock(&mdsc->mutex);
2751}
2752
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2753/*
2754 * Encode information about a cap for a reconnect with the MDS.
2755 */
2756static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2757			  void *arg)
2758{
2759	union {
2760		struct ceph_mds_cap_reconnect v2;
2761		struct ceph_mds_cap_reconnect_v1 v1;
2762	} rec;
2763	struct ceph_inode_info *ci;
2764	struct ceph_reconnect_state *recon_state = arg;
2765	struct ceph_pagelist *pagelist = recon_state->pagelist;
2766	char *path;
2767	int pathlen, err;
2768	u64 pathbase;
2769	u64 snap_follows;
2770	struct dentry *dentry;
2771
2772	ci = cap->ci;
2773
2774	dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2775	     inode, ceph_vinop(inode), cap, cap->cap_id,
2776	     ceph_cap_string(cap->issued));
2777	err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2778	if (err)
2779		return err;
2780
2781	dentry = d_find_alias(inode);
2782	if (dentry) {
2783		path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2784		if (IS_ERR(path)) {
2785			err = PTR_ERR(path);
2786			goto out_dput;
2787		}
2788	} else {
2789		path = NULL;
2790		pathlen = 0;
2791		pathbase = 0;
2792	}
2793
2794	spin_lock(&ci->i_ceph_lock);
2795	cap->seq = 0;        /* reset cap seq */
2796	cap->issue_seq = 0;  /* and issue_seq */
2797	cap->mseq = 0;       /* and migrate_seq */
2798	cap->cap_gen = cap->session->s_cap_gen;
2799
2800	if (recon_state->msg_version >= 2) {
2801		rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2802		rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2803		rec.v2.issued = cpu_to_le32(cap->issued);
2804		rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2805		rec.v2.pathbase = cpu_to_le64(pathbase);
2806		rec.v2.flock_len = 0;
 
2807	} else {
2808		rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2809		rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2810		rec.v1.issued = cpu_to_le32(cap->issued);
2811		rec.v1.size = cpu_to_le64(inode->i_size);
2812		ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2813		ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2814		rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2815		rec.v1.pathbase = cpu_to_le64(pathbase);
2816	}
2817
2818	if (list_empty(&ci->i_cap_snaps)) {
2819		snap_follows = 0;
2820	} else {
2821		struct ceph_cap_snap *capsnap =
2822			list_first_entry(&ci->i_cap_snaps,
2823					 struct ceph_cap_snap, ci_item);
2824		snap_follows = capsnap->follows;
2825	}
2826	spin_unlock(&ci->i_ceph_lock);
2827
2828	if (recon_state->msg_version >= 2) {
2829		int num_fcntl_locks, num_flock_locks;
2830		struct ceph_filelock *flocks;
2831		size_t struct_len, total_len = 0;
2832		u8 struct_v = 0;
2833
2834encode_again:
2835		ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2836		flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2837				 sizeof(struct ceph_filelock), GFP_NOFS);
2838		if (!flocks) {
2839			err = -ENOMEM;
2840			goto out_free;
2841		}
2842		err = ceph_encode_locks_to_buffer(inode, flocks,
2843						  num_fcntl_locks,
2844						  num_flock_locks);
2845		if (err) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2846			kfree(flocks);
2847			if (err == -ENOSPC)
2848				goto encode_again;
2849			goto out_free;
2850		}
2851
2852		if (recon_state->msg_version >= 3) {
2853			/* version, compat_version and struct_len */
2854			total_len = 2 * sizeof(u8) + sizeof(u32);
2855			struct_v = 2;
2856		}
2857		/*
2858		 * number of encoded locks is stable, so copy to pagelist
2859		 */
2860		struct_len = 2 * sizeof(u32) +
2861			    (num_fcntl_locks + num_flock_locks) *
2862			    sizeof(struct ceph_filelock);
2863		rec.v2.flock_len = cpu_to_le32(struct_len);
2864
2865		struct_len += sizeof(rec.v2);
2866		struct_len += sizeof(u32) + pathlen;
2867
2868		if (struct_v >= 2)
2869			struct_len += sizeof(u64); /* snap_follows */
2870
2871		total_len += struct_len;
 
 
 
 
 
 
 
 
2872		err = ceph_pagelist_reserve(pagelist, total_len);
 
 
2873
2874		if (!err) {
2875			if (recon_state->msg_version >= 3) {
2876				ceph_pagelist_encode_8(pagelist, struct_v);
2877				ceph_pagelist_encode_8(pagelist, 1);
2878				ceph_pagelist_encode_32(pagelist, struct_len);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2879			}
2880			ceph_pagelist_encode_string(pagelist, path, pathlen);
2881			ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
2882			ceph_locks_to_pagelist(flocks, pagelist,
2883					       num_fcntl_locks,
2884					       num_flock_locks);
2885			if (struct_v >= 2)
2886				ceph_pagelist_encode_64(pagelist, snap_follows);
2887		}
2888		kfree(flocks);
2889	} else {
2890		size_t size = sizeof(u32) + pathlen + sizeof(rec.v1);
2891		err = ceph_pagelist_reserve(pagelist, size);
2892		if (!err) {
2893			ceph_pagelist_encode_string(pagelist, path, pathlen);
2894			ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
2895		}
 
 
 
 
 
 
2896	}
2897
2898	recon_state->nr_caps++;
2899out_free:
2900	kfree(path);
2901out_dput:
2902	dput(dentry);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2903	return err;
2904}
2905
2906
2907/*
2908 * If an MDS fails and recovers, clients need to reconnect in order to
2909 * reestablish shared state.  This includes all caps issued through
2910 * this session _and_ the snap_realm hierarchy.  Because it's not
2911 * clear which snap realms the mds cares about, we send everything we
2912 * know about.. that ensures we'll then get any new info the
2913 * recovering MDS might have.
2914 *
2915 * This is a relatively heavyweight operation, but it's rare.
2916 *
2917 * called with mdsc->mutex held.
2918 */
2919static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2920			       struct ceph_mds_session *session)
2921{
2922	struct ceph_msg *reply;
2923	struct rb_node *p;
2924	int mds = session->s_mds;
2925	int err = -ENOMEM;
2926	int s_nr_caps;
2927	struct ceph_pagelist *pagelist;
2928	struct ceph_reconnect_state recon_state;
 
2929
2930	pr_info("mds%d reconnect start\n", mds);
2931
2932	pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2933	if (!pagelist)
2934		goto fail_nopagelist;
2935	ceph_pagelist_init(pagelist);
2936
2937	reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2938	if (!reply)
2939		goto fail_nomsg;
2940
2941	mutex_lock(&session->s_mutex);
2942	session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2943	session->s_seq = 0;
2944
2945	dout("session %p state %s\n", session,
2946	     ceph_session_state_name(session->s_state));
2947
2948	spin_lock(&session->s_gen_ttl_lock);
2949	session->s_cap_gen++;
2950	spin_unlock(&session->s_gen_ttl_lock);
2951
2952	spin_lock(&session->s_cap_lock);
2953	/* don't know if session is readonly */
2954	session->s_readonly = 0;
2955	/*
2956	 * notify __ceph_remove_cap() that we are composing cap reconnect.
2957	 * If a cap get released before being added to the cap reconnect,
2958	 * __ceph_remove_cap() should skip queuing cap release.
2959	 */
2960	session->s_cap_reconnect = 1;
2961	/* drop old cap expires; we're about to reestablish that state */
2962	cleanup_cap_releases(mdsc, session);
 
 
2963
2964	/* trim unused caps to reduce MDS's cache rejoin time */
2965	if (mdsc->fsc->sb->s_root)
2966		shrink_dcache_parent(mdsc->fsc->sb->s_root);
2967
2968	ceph_con_close(&session->s_con);
2969	ceph_con_open(&session->s_con,
2970		      CEPH_ENTITY_TYPE_MDS, mds,
2971		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2972
2973	/* replay unsafe requests */
2974	replay_unsafe_requests(mdsc, session);
2975
 
 
2976	down_read(&mdsc->snap_rwsem);
2977
2978	/* traverse this session's caps */
2979	s_nr_caps = session->s_nr_caps;
2980	err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2981	if (err)
2982		goto fail;
2983
2984	recon_state.nr_caps = 0;
2985	recon_state.pagelist = pagelist;
2986	if (session->s_con.peer_features & CEPH_FEATURE_MDSENC)
 
2987		recon_state.msg_version = 3;
2988	else if (session->s_con.peer_features & CEPH_FEATURE_FLOCK)
2989		recon_state.msg_version = 2;
2990	else
2991		recon_state.msg_version = 1;
2992	err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2993	if (err < 0)
2994		goto fail;
2995
2996	spin_lock(&session->s_cap_lock);
2997	session->s_cap_reconnect = 0;
2998	spin_unlock(&session->s_cap_lock);
2999
3000	/*
3001	 * snaprealms.  we provide mds with the ino, seq (version), and
3002	 * parent for all of our realms.  If the mds has any newer info,
3003	 * it will tell us.
3004	 */
3005	for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3006		struct ceph_snap_realm *realm =
3007			rb_entry(p, struct ceph_snap_realm, node);
3008		struct ceph_mds_snaprealm_reconnect sr_rec;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3009
3010		dout(" adding snap realm %llx seq %lld parent %llx\n",
3011		     realm->ino, realm->seq, realm->parent_ino);
3012		sr_rec.ino = cpu_to_le64(realm->ino);
3013		sr_rec.seq = cpu_to_le64(realm->seq);
3014		sr_rec.parent = cpu_to_le64(realm->parent_ino);
3015		err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3016		if (err)
3017			goto fail;
3018	}
3019
3020	reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3021
3022	/* raced with cap release? */
3023	if (s_nr_caps != recon_state.nr_caps) {
3024		struct page *page = list_first_entry(&pagelist->head,
3025						     struct page, lru);
3026		__le32 *addr = kmap_atomic(page);
3027		*addr = cpu_to_le32(recon_state.nr_caps);
 
 
 
 
 
3028		kunmap_atomic(addr);
3029	}
3030
3031	reply->hdr.data_len = cpu_to_le32(pagelist->length);
3032	ceph_msg_data_add_pagelist(reply, pagelist);
 
3033
3034	ceph_early_kick_flushing_caps(mdsc, session);
 
3035
3036	ceph_con_send(&session->s_con, reply);
3037
3038	mutex_unlock(&session->s_mutex);
3039
3040	mutex_lock(&mdsc->mutex);
3041	__wake_requests(mdsc, &session->s_waiting);
3042	mutex_unlock(&mdsc->mutex);
3043
3044	up_read(&mdsc->snap_rwsem);
 
3045	return;
3046
3047fail:
3048	ceph_msg_put(reply);
3049	up_read(&mdsc->snap_rwsem);
3050	mutex_unlock(&session->s_mutex);
3051fail_nomsg:
3052	ceph_pagelist_release(pagelist);
3053fail_nopagelist:
3054	pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3055	return;
3056}
3057
3058
3059/*
3060 * compare old and new mdsmaps, kicking requests
3061 * and closing out old connections as necessary
3062 *
3063 * called under mdsc->mutex.
3064 */
3065static void check_new_map(struct ceph_mds_client *mdsc,
3066			  struct ceph_mdsmap *newmap,
3067			  struct ceph_mdsmap *oldmap)
3068{
3069	int i;
3070	int oldstate, newstate;
3071	struct ceph_mds_session *s;
3072
3073	dout("check_new_map new %u old %u\n",
3074	     newmap->m_epoch, oldmap->m_epoch);
3075
3076	for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3077		if (mdsc->sessions[i] == NULL)
3078			continue;
3079		s = mdsc->sessions[i];
3080		oldstate = ceph_mdsmap_get_state(oldmap, i);
3081		newstate = ceph_mdsmap_get_state(newmap, i);
3082
3083		dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3084		     i, ceph_mds_state_name(oldstate),
3085		     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3086		     ceph_mds_state_name(newstate),
3087		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3088		     ceph_session_state_name(s->s_state));
3089
3090		if (i >= newmap->m_max_mds ||
3091		    memcmp(ceph_mdsmap_get_addr(oldmap, i),
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3092			   ceph_mdsmap_get_addr(newmap, i),
3093			   sizeof(struct ceph_entity_addr))) {
3094			if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3095				/* the session never opened, just close it
3096				 * out now */
3097				__wake_requests(mdsc, &s->s_waiting);
3098				__unregister_session(mdsc, s);
3099			} else {
3100				/* just close it */
3101				mutex_unlock(&mdsc->mutex);
3102				mutex_lock(&s->s_mutex);
3103				mutex_lock(&mdsc->mutex);
3104				ceph_con_close(&s->s_con);
3105				mutex_unlock(&s->s_mutex);
3106				s->s_state = CEPH_MDS_SESSION_RESTARTING;
3107			}
3108		} else if (oldstate == newstate) {
3109			continue;  /* nothing new with this mds */
3110		}
3111
3112		/*
3113		 * send reconnect?
3114		 */
3115		if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3116		    newstate >= CEPH_MDS_STATE_RECONNECT) {
3117			mutex_unlock(&mdsc->mutex);
3118			send_mds_reconnect(mdsc, s);
3119			mutex_lock(&mdsc->mutex);
3120		}
3121
3122		/*
3123		 * kick request on any mds that has gone active.
3124		 */
3125		if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3126		    newstate >= CEPH_MDS_STATE_ACTIVE) {
3127			if (oldstate != CEPH_MDS_STATE_CREATING &&
3128			    oldstate != CEPH_MDS_STATE_STARTING)
3129				pr_info("mds%d recovery completed\n", s->s_mds);
3130			kick_requests(mdsc, i);
3131			ceph_kick_flushing_caps(mdsc, s);
3132			wake_up_session_caps(s, 1);
3133		}
3134	}
3135
3136	for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3137		s = mdsc->sessions[i];
3138		if (!s)
3139			continue;
3140		if (!ceph_mdsmap_is_laggy(newmap, i))
3141			continue;
3142		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3143		    s->s_state == CEPH_MDS_SESSION_HUNG ||
3144		    s->s_state == CEPH_MDS_SESSION_CLOSING) {
3145			dout(" connecting to export targets of laggy mds%d\n",
3146			     i);
3147			__open_export_target_sessions(mdsc, s);
3148		}
3149	}
3150}
3151
3152
3153
3154/*
3155 * leases
3156 */
3157
3158/*
3159 * caller must hold session s_mutex, dentry->d_lock
3160 */
3161void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3162{
3163	struct ceph_dentry_info *di = ceph_dentry(dentry);
3164
3165	ceph_put_mds_session(di->lease_session);
3166	di->lease_session = NULL;
3167}
3168
3169static void handle_lease(struct ceph_mds_client *mdsc,
3170			 struct ceph_mds_session *session,
3171			 struct ceph_msg *msg)
3172{
3173	struct super_block *sb = mdsc->fsc->sb;
3174	struct inode *inode;
3175	struct dentry *parent, *dentry;
3176	struct ceph_dentry_info *di;
3177	int mds = session->s_mds;
3178	struct ceph_mds_lease *h = msg->front.iov_base;
3179	u32 seq;
3180	struct ceph_vino vino;
3181	struct qstr dname;
3182	int release = 0;
3183
3184	dout("handle_lease from mds%d\n", mds);
3185
3186	/* decode */
3187	if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3188		goto bad;
3189	vino.ino = le64_to_cpu(h->ino);
3190	vino.snap = CEPH_NOSNAP;
3191	seq = le32_to_cpu(h->seq);
3192	dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3193	dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3194	if (dname.len != get_unaligned_le32(h+1))
3195		goto bad;
 
3196
3197	/* lookup inode */
3198	inode = ceph_find_inode(sb, vino);
3199	dout("handle_lease %s, ino %llx %p %.*s\n",
3200	     ceph_lease_op_name(h->action), vino.ino, inode,
3201	     dname.len, dname.name);
3202
3203	mutex_lock(&session->s_mutex);
3204	session->s_seq++;
3205
3206	if (inode == NULL) {
3207		dout("handle_lease no inode %llx\n", vino.ino);
3208		goto release;
3209	}
3210
3211	/* dentry */
3212	parent = d_find_alias(inode);
3213	if (!parent) {
3214		dout("no parent dentry on inode %p\n", inode);
3215		WARN_ON(1);
3216		goto release;  /* hrm... */
3217	}
3218	dname.hash = full_name_hash(parent, dname.name, dname.len);
3219	dentry = d_lookup(parent, &dname);
3220	dput(parent);
3221	if (!dentry)
3222		goto release;
3223
3224	spin_lock(&dentry->d_lock);
3225	di = ceph_dentry(dentry);
3226	switch (h->action) {
3227	case CEPH_MDS_LEASE_REVOKE:
3228		if (di->lease_session == session) {
3229			if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3230				h->seq = cpu_to_le32(di->lease_seq);
3231			__ceph_mdsc_drop_dentry_lease(dentry);
3232		}
3233		release = 1;
3234		break;
3235
3236	case CEPH_MDS_LEASE_RENEW:
3237		if (di->lease_session == session &&
3238		    di->lease_gen == session->s_cap_gen &&
3239		    di->lease_renew_from &&
3240		    di->lease_renew_after == 0) {
3241			unsigned long duration =
3242				msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3243
3244			di->lease_seq = seq;
3245			di->time = di->lease_renew_from + duration;
3246			di->lease_renew_after = di->lease_renew_from +
3247				(duration >> 1);
3248			di->lease_renew_from = 0;
3249		}
3250		break;
3251	}
3252	spin_unlock(&dentry->d_lock);
3253	dput(dentry);
3254
3255	if (!release)
3256		goto out;
3257
3258release:
3259	/* let's just reuse the same message */
3260	h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3261	ceph_msg_get(msg);
3262	ceph_con_send(&session->s_con, msg);
3263
3264out:
3265	iput(inode);
3266	mutex_unlock(&session->s_mutex);
 
 
3267	return;
3268
3269bad:
3270	pr_err("corrupt lease message\n");
3271	ceph_msg_dump(msg);
3272}
3273
3274void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3275			      struct inode *inode,
3276			      struct dentry *dentry, char action,
3277			      u32 seq)
3278{
3279	struct ceph_msg *msg;
3280	struct ceph_mds_lease *lease;
3281	int len = sizeof(*lease) + sizeof(u32);
3282	int dnamelen = 0;
3283
3284	dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3285	     inode, dentry, ceph_lease_op_name(action), session->s_mds);
3286	dnamelen = dentry->d_name.len;
3287	len += dnamelen;
3288
3289	msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3290	if (!msg)
3291		return;
3292	lease = msg->front.iov_base;
3293	lease->action = action;
3294	lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3295	lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3296	lease->seq = cpu_to_le32(seq);
3297	put_unaligned_le32(dnamelen, lease + 1);
3298	memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3299
 
 
 
 
 
 
 
 
 
3300	/*
3301	 * if this is a preemptive lease RELEASE, no need to
3302	 * flush request stream, since the actual request will
3303	 * soon follow.
3304	 */
3305	msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3306
3307	ceph_con_send(&session->s_con, msg);
3308}
3309
3310/*
3311 * drop all leases (and dentry refs) in preparation for umount
3312 */
3313static void drop_leases(struct ceph_mds_client *mdsc)
3314{
3315	int i;
3316
3317	dout("drop_leases\n");
3318	mutex_lock(&mdsc->mutex);
3319	for (i = 0; i < mdsc->max_sessions; i++) {
3320		struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3321		if (!s)
3322			continue;
3323		mutex_unlock(&mdsc->mutex);
3324		mutex_lock(&s->s_mutex);
3325		mutex_unlock(&s->s_mutex);
3326		ceph_put_mds_session(s);
3327		mutex_lock(&mdsc->mutex);
3328	}
3329	mutex_unlock(&mdsc->mutex);
3330}
3331
 
 
 
3332
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3333
3334/*
3335 * delayed work -- periodically trim expired leases, renew caps with mds
3336 */
3337static void schedule_delayed(struct ceph_mds_client *mdsc)
3338{
3339	int delay = 5;
3340	unsigned hz = round_jiffies_relative(HZ * delay);
3341	schedule_delayed_work(&mdsc->delayed_work, hz);
3342}
3343
3344static void delayed_work(struct work_struct *work)
3345{
3346	int i;
3347	struct ceph_mds_client *mdsc =
3348		container_of(work, struct ceph_mds_client, delayed_work.work);
3349	int renew_interval;
3350	int renew_caps;
3351
3352	dout("mdsc delayed_work\n");
3353	ceph_check_delayed_caps(mdsc);
3354
3355	mutex_lock(&mdsc->mutex);
3356	renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3357	renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3358				   mdsc->last_renew_caps);
3359	if (renew_caps)
3360		mdsc->last_renew_caps = jiffies;
3361
3362	for (i = 0; i < mdsc->max_sessions; i++) {
3363		struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3364		if (s == NULL)
3365			continue;
3366		if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3367			dout("resending session close request for mds%d\n",
3368			     s->s_mds);
3369			request_close_session(mdsc, s);
3370			ceph_put_mds_session(s);
3371			continue;
3372		}
3373		if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3374			if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3375				s->s_state = CEPH_MDS_SESSION_HUNG;
3376				pr_info("mds%d hung\n", s->s_mds);
3377			}
3378		}
3379		if (s->s_state < CEPH_MDS_SESSION_OPEN) {
 
 
3380			/* this mds is failed or recovering, just wait */
3381			ceph_put_mds_session(s);
3382			continue;
3383		}
3384		mutex_unlock(&mdsc->mutex);
3385
3386		mutex_lock(&s->s_mutex);
3387		if (renew_caps)
3388			send_renew_caps(mdsc, s);
3389		else
3390			ceph_con_keepalive(&s->s_con);
3391		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3392		    s->s_state == CEPH_MDS_SESSION_HUNG)
3393			ceph_send_cap_releases(mdsc, s);
3394		mutex_unlock(&s->s_mutex);
3395		ceph_put_mds_session(s);
3396
3397		mutex_lock(&mdsc->mutex);
3398	}
3399	mutex_unlock(&mdsc->mutex);
3400
 
 
 
 
 
 
 
 
3401	schedule_delayed(mdsc);
3402}
3403
3404int ceph_mdsc_init(struct ceph_fs_client *fsc)
3405
3406{
3407	struct ceph_mds_client *mdsc;
3408
3409	mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3410	if (!mdsc)
3411		return -ENOMEM;
3412	mdsc->fsc = fsc;
3413	fsc->mdsc = mdsc;
3414	mutex_init(&mdsc->mutex);
3415	mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3416	if (mdsc->mdsmap == NULL) {
3417		kfree(mdsc);
3418		return -ENOMEM;
3419	}
3420
 
3421	init_completion(&mdsc->safe_umount_waiters);
3422	init_waitqueue_head(&mdsc->session_close_wq);
3423	INIT_LIST_HEAD(&mdsc->waiting_for_map);
3424	mdsc->sessions = NULL;
3425	atomic_set(&mdsc->num_sessions, 0);
3426	mdsc->max_sessions = 0;
3427	mdsc->stopping = 0;
 
 
 
3428	mdsc->last_snap_seq = 0;
3429	init_rwsem(&mdsc->snap_rwsem);
3430	mdsc->snap_realms = RB_ROOT;
3431	INIT_LIST_HEAD(&mdsc->snap_empty);
 
3432	spin_lock_init(&mdsc->snap_empty_lock);
3433	mdsc->last_tid = 0;
3434	mdsc->oldest_tid = 0;
3435	mdsc->request_tree = RB_ROOT;
3436	INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3437	mdsc->last_renew_caps = jiffies;
3438	INIT_LIST_HEAD(&mdsc->cap_delay_list);
3439	spin_lock_init(&mdsc->cap_delay_lock);
3440	INIT_LIST_HEAD(&mdsc->snap_flush_list);
3441	spin_lock_init(&mdsc->snap_flush_lock);
3442	mdsc->last_cap_flush_tid = 1;
3443	INIT_LIST_HEAD(&mdsc->cap_flush_list);
3444	INIT_LIST_HEAD(&mdsc->cap_dirty);
3445	INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3446	mdsc->num_cap_flushing = 0;
3447	spin_lock_init(&mdsc->cap_dirty_lock);
3448	init_waitqueue_head(&mdsc->cap_flushing_wq);
3449	spin_lock_init(&mdsc->dentry_lru_lock);
3450	INIT_LIST_HEAD(&mdsc->dentry_lru);
 
 
 
 
3451
3452	ceph_caps_init(mdsc);
3453	ceph_adjust_min_caps(mdsc, fsc->min_caps);
 
 
 
 
3454
3455	init_rwsem(&mdsc->pool_perm_rwsem);
3456	mdsc->pool_perm_tree = RB_ROOT;
3457
 
 
3458	return 0;
3459}
3460
3461/*
3462 * Wait for safe replies on open mds requests.  If we time out, drop
3463 * all requests from the tree to avoid dangling dentry refs.
3464 */
3465static void wait_requests(struct ceph_mds_client *mdsc)
3466{
3467	struct ceph_options *opts = mdsc->fsc->client->options;
3468	struct ceph_mds_request *req;
3469
3470	mutex_lock(&mdsc->mutex);
3471	if (__get_oldest_req(mdsc)) {
3472		mutex_unlock(&mdsc->mutex);
3473
3474		dout("wait_requests waiting for requests\n");
3475		wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3476				    ceph_timeout_jiffies(opts->mount_timeout));
3477
3478		/* tear down remaining requests */
3479		mutex_lock(&mdsc->mutex);
3480		while ((req = __get_oldest_req(mdsc))) {
3481			dout("wait_requests timed out on tid %llu\n",
3482			     req->r_tid);
 
3483			__unregister_request(mdsc, req);
3484		}
3485	}
3486	mutex_unlock(&mdsc->mutex);
3487	dout("wait_requests done\n");
3488}
3489
3490/*
3491 * called before mount is ro, and before dentries are torn down.
3492 * (hmm, does this still race with new lookups?)
3493 */
3494void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3495{
3496	dout("pre_umount\n");
3497	mdsc->stopping = 1;
3498
3499	drop_leases(mdsc);
3500	ceph_flush_dirty_caps(mdsc);
3501	wait_requests(mdsc);
3502
3503	/*
3504	 * wait for reply handlers to drop their request refs and
3505	 * their inode/dcache refs
3506	 */
3507	ceph_msgr_flush();
 
 
3508}
3509
3510/*
3511 * wait for all write mds requests to flush.
3512 */
3513static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3514{
3515	struct ceph_mds_request *req = NULL, *nextreq;
3516	struct rb_node *n;
3517
3518	mutex_lock(&mdsc->mutex);
3519	dout("wait_unsafe_requests want %lld\n", want_tid);
3520restart:
3521	req = __get_oldest_req(mdsc);
3522	while (req && req->r_tid <= want_tid) {
3523		/* find next request */
3524		n = rb_next(&req->r_node);
3525		if (n)
3526			nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3527		else
3528			nextreq = NULL;
3529		if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3530		    (req->r_op & CEPH_MDS_OP_WRITE)) {
3531			/* write op */
3532			ceph_mdsc_get_request(req);
3533			if (nextreq)
3534				ceph_mdsc_get_request(nextreq);
3535			mutex_unlock(&mdsc->mutex);
3536			dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3537			     req->r_tid, want_tid);
3538			wait_for_completion(&req->r_safe_completion);
3539			mutex_lock(&mdsc->mutex);
3540			ceph_mdsc_put_request(req);
3541			if (!nextreq)
3542				break;  /* next dne before, so we're done! */
3543			if (RB_EMPTY_NODE(&nextreq->r_node)) {
3544				/* next request was removed from tree */
3545				ceph_mdsc_put_request(nextreq);
3546				goto restart;
3547			}
3548			ceph_mdsc_put_request(nextreq);  /* won't go away */
3549		}
3550		req = nextreq;
3551	}
3552	mutex_unlock(&mdsc->mutex);
3553	dout("wait_unsafe_requests done\n");
3554}
3555
3556void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3557{
3558	u64 want_tid, want_flush;
3559
3560	if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3561		return;
3562
3563	dout("sync\n");
3564	mutex_lock(&mdsc->mutex);
3565	want_tid = mdsc->last_tid;
3566	mutex_unlock(&mdsc->mutex);
3567
3568	ceph_flush_dirty_caps(mdsc);
3569	spin_lock(&mdsc->cap_dirty_lock);
3570	want_flush = mdsc->last_cap_flush_tid;
3571	if (!list_empty(&mdsc->cap_flush_list)) {
3572		struct ceph_cap_flush *cf =
3573			list_last_entry(&mdsc->cap_flush_list,
3574					struct ceph_cap_flush, g_list);
3575		cf->wake = true;
3576	}
3577	spin_unlock(&mdsc->cap_dirty_lock);
3578
3579	dout("sync want tid %lld flush_seq %lld\n",
3580	     want_tid, want_flush);
3581
3582	wait_unsafe_requests(mdsc, want_tid);
3583	wait_caps_flush(mdsc, want_flush);
3584}
3585
3586/*
3587 * true if all sessions are closed, or we force unmount
3588 */
3589static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
3590{
3591	if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3592		return true;
3593	return atomic_read(&mdsc->num_sessions) <= skipped;
3594}
3595
3596/*
3597 * called after sb is ro.
3598 */
3599void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3600{
3601	struct ceph_options *opts = mdsc->fsc->client->options;
3602	struct ceph_mds_session *session;
3603	int i;
3604	int skipped = 0;
3605
3606	dout("close_sessions\n");
3607
3608	/* close sessions */
3609	mutex_lock(&mdsc->mutex);
3610	for (i = 0; i < mdsc->max_sessions; i++) {
3611		session = __ceph_lookup_mds_session(mdsc, i);
3612		if (!session)
3613			continue;
3614		mutex_unlock(&mdsc->mutex);
3615		mutex_lock(&session->s_mutex);
3616		if (__close_session(mdsc, session) <= 0)
3617			skipped++;
3618		mutex_unlock(&session->s_mutex);
3619		ceph_put_mds_session(session);
3620		mutex_lock(&mdsc->mutex);
3621	}
3622	mutex_unlock(&mdsc->mutex);
3623
3624	dout("waiting for sessions to close\n");
3625	wait_event_timeout(mdsc->session_close_wq,
3626			   done_closing_sessions(mdsc, skipped),
3627			   ceph_timeout_jiffies(opts->mount_timeout));
3628
3629	/* tear down remaining sessions */
3630	mutex_lock(&mdsc->mutex);
3631	for (i = 0; i < mdsc->max_sessions; i++) {
3632		if (mdsc->sessions[i]) {
3633			session = get_session(mdsc->sessions[i]);
3634			__unregister_session(mdsc, session);
3635			mutex_unlock(&mdsc->mutex);
3636			mutex_lock(&session->s_mutex);
3637			remove_session_caps(session);
3638			mutex_unlock(&session->s_mutex);
3639			ceph_put_mds_session(session);
3640			mutex_lock(&mdsc->mutex);
3641		}
3642	}
3643	WARN_ON(!list_empty(&mdsc->cap_delay_list));
3644	mutex_unlock(&mdsc->mutex);
3645
 
3646	ceph_cleanup_empty_realms(mdsc);
3647
 
3648	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3649
3650	dout("stopped\n");
3651}
3652
3653void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
3654{
3655	struct ceph_mds_session *session;
3656	int mds;
3657
3658	dout("force umount\n");
3659
3660	mutex_lock(&mdsc->mutex);
3661	for (mds = 0; mds < mdsc->max_sessions; mds++) {
3662		session = __ceph_lookup_mds_session(mdsc, mds);
3663		if (!session)
3664			continue;
 
 
 
 
3665		mutex_unlock(&mdsc->mutex);
 
3666		mutex_lock(&session->s_mutex);
3667		__close_session(mdsc, session);
3668		if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
3669			cleanup_session_requests(mdsc, session);
3670			remove_session_caps(session);
3671		}
3672		mutex_unlock(&session->s_mutex);
3673		ceph_put_mds_session(session);
 
3674		mutex_lock(&mdsc->mutex);
3675		kick_requests(mdsc, mds);
3676	}
3677	__wake_requests(mdsc, &mdsc->waiting_for_map);
3678	mutex_unlock(&mdsc->mutex);
3679}
3680
3681static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3682{
3683	dout("stop\n");
3684	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3685	if (mdsc->mdsmap)
3686		ceph_mdsmap_destroy(mdsc->mdsmap);
3687	kfree(mdsc->sessions);
3688	ceph_caps_finalize(mdsc);
3689	ceph_pool_perm_destroy(mdsc);
3690}
3691
3692void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3693{
3694	struct ceph_mds_client *mdsc = fsc->mdsc;
 
3695
3696	dout("mdsc_destroy %p\n", mdsc);
3697	ceph_mdsc_stop(mdsc);
3698
3699	/* flush out any connection work with references to us */
3700	ceph_msgr_flush();
3701
 
 
3702	fsc->mdsc = NULL;
3703	kfree(mdsc);
3704	dout("mdsc_destroy %p done\n", mdsc);
3705}
3706
3707void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3708{
3709	struct ceph_fs_client *fsc = mdsc->fsc;
3710	const char *mds_namespace = fsc->mount_options->mds_namespace;
3711	void *p = msg->front.iov_base;
3712	void *end = p + msg->front.iov_len;
3713	u32 epoch;
3714	u32 map_len;
3715	u32 num_fs;
3716	u32 mount_fscid = (u32)-1;
3717	u8 struct_v, struct_cv;
3718	int err = -EINVAL;
3719
3720	ceph_decode_need(&p, end, sizeof(u32), bad);
3721	epoch = ceph_decode_32(&p);
3722
3723	dout("handle_fsmap epoch %u\n", epoch);
3724
3725	ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
3726	struct_v = ceph_decode_8(&p);
3727	struct_cv = ceph_decode_8(&p);
3728	map_len = ceph_decode_32(&p);
3729
3730	ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
3731	p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
3732
3733	num_fs = ceph_decode_32(&p);
3734	while (num_fs-- > 0) {
3735		void *info_p, *info_end;
3736		u32 info_len;
3737		u8 info_v, info_cv;
3738		u32 fscid, namelen;
3739
3740		ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
3741		info_v = ceph_decode_8(&p);
3742		info_cv = ceph_decode_8(&p);
3743		info_len = ceph_decode_32(&p);
3744		ceph_decode_need(&p, end, info_len, bad);
3745		info_p = p;
3746		info_end = p + info_len;
3747		p = info_end;
3748
3749		ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
3750		fscid = ceph_decode_32(&info_p);
3751		namelen = ceph_decode_32(&info_p);
3752		ceph_decode_need(&info_p, info_end, namelen, bad);
3753
3754		if (mds_namespace &&
3755		    strlen(mds_namespace) == namelen &&
3756		    !strncmp(mds_namespace, (char *)info_p, namelen)) {
3757			mount_fscid = fscid;
3758			break;
3759		}
3760	}
3761
3762	ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
3763	if (mount_fscid != (u32)-1) {
3764		fsc->client->monc.fs_cluster_id = mount_fscid;
3765		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
3766				   0, true);
3767		ceph_monc_renew_subs(&fsc->client->monc);
3768	} else {
3769		err = -ENOENT;
3770		goto err_out;
3771	}
3772	return;
 
3773bad:
3774	pr_err("error decoding fsmap\n");
3775err_out:
3776	mutex_lock(&mdsc->mutex);
3777	mdsc->mdsmap_err = -ENOENT;
3778	__wake_requests(mdsc, &mdsc->waiting_for_map);
3779	mutex_unlock(&mdsc->mutex);
3780	return;
3781}
3782
3783/*
3784 * handle mds map update.
3785 */
3786void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3787{
3788	u32 epoch;
3789	u32 maplen;
3790	void *p = msg->front.iov_base;
3791	void *end = p + msg->front.iov_len;
3792	struct ceph_mdsmap *newmap, *oldmap;
3793	struct ceph_fsid fsid;
3794	int err = -EINVAL;
3795
3796	ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3797	ceph_decode_copy(&p, &fsid, sizeof(fsid));
3798	if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3799		return;
3800	epoch = ceph_decode_32(&p);
3801	maplen = ceph_decode_32(&p);
3802	dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3803
3804	/* do we need it? */
3805	mutex_lock(&mdsc->mutex);
3806	if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3807		dout("handle_map epoch %u <= our %u\n",
3808		     epoch, mdsc->mdsmap->m_epoch);
3809		mutex_unlock(&mdsc->mutex);
3810		return;
3811	}
3812
3813	newmap = ceph_mdsmap_decode(&p, end);
3814	if (IS_ERR(newmap)) {
3815		err = PTR_ERR(newmap);
3816		goto bad_unlock;
3817	}
3818
3819	/* swap into place */
3820	if (mdsc->mdsmap) {
3821		oldmap = mdsc->mdsmap;
3822		mdsc->mdsmap = newmap;
3823		check_new_map(mdsc, newmap, oldmap);
3824		ceph_mdsmap_destroy(oldmap);
3825	} else {
3826		mdsc->mdsmap = newmap;  /* first mds map */
3827	}
3828	mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
 
3829
3830	__wake_requests(mdsc, &mdsc->waiting_for_map);
3831	ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
3832			  mdsc->mdsmap->m_epoch);
3833
3834	mutex_unlock(&mdsc->mutex);
3835	schedule_delayed(mdsc);
3836	return;
3837
3838bad_unlock:
3839	mutex_unlock(&mdsc->mutex);
3840bad:
3841	pr_err("error decoding mdsmap %d\n", err);
3842	return;
3843}
3844
3845static struct ceph_connection *con_get(struct ceph_connection *con)
3846{
3847	struct ceph_mds_session *s = con->private;
3848
3849	if (get_session(s)) {
3850		dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3851		return con;
3852	}
3853	dout("mdsc con_get %p FAIL\n", s);
3854	return NULL;
3855}
3856
3857static void con_put(struct ceph_connection *con)
3858{
3859	struct ceph_mds_session *s = con->private;
3860
3861	dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3862	ceph_put_mds_session(s);
3863}
3864
3865/*
3866 * if the client is unresponsive for long enough, the mds will kill
3867 * the session entirely.
3868 */
3869static void peer_reset(struct ceph_connection *con)
3870{
3871	struct ceph_mds_session *s = con->private;
3872	struct ceph_mds_client *mdsc = s->s_mdsc;
3873
3874	pr_warn("mds%d closed our session\n", s->s_mds);
3875	send_mds_reconnect(mdsc, s);
3876}
3877
3878static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3879{
3880	struct ceph_mds_session *s = con->private;
3881	struct ceph_mds_client *mdsc = s->s_mdsc;
3882	int type = le16_to_cpu(msg->hdr.type);
3883
3884	mutex_lock(&mdsc->mutex);
3885	if (__verify_registered_session(mdsc, s) < 0) {
3886		mutex_unlock(&mdsc->mutex);
3887		goto out;
3888	}
3889	mutex_unlock(&mdsc->mutex);
3890
3891	switch (type) {
3892	case CEPH_MSG_MDS_MAP:
3893		ceph_mdsc_handle_mdsmap(mdsc, msg);
3894		break;
3895	case CEPH_MSG_FS_MAP_USER:
3896		ceph_mdsc_handle_fsmap(mdsc, msg);
3897		break;
3898	case CEPH_MSG_CLIENT_SESSION:
3899		handle_session(s, msg);
3900		break;
3901	case CEPH_MSG_CLIENT_REPLY:
3902		handle_reply(s, msg);
3903		break;
3904	case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3905		handle_forward(mdsc, s, msg);
3906		break;
3907	case CEPH_MSG_CLIENT_CAPS:
3908		ceph_handle_caps(s, msg);
3909		break;
3910	case CEPH_MSG_CLIENT_SNAP:
3911		ceph_handle_snap(mdsc, s, msg);
3912		break;
3913	case CEPH_MSG_CLIENT_LEASE:
3914		handle_lease(mdsc, s, msg);
3915		break;
 
 
 
3916
3917	default:
3918		pr_err("received unknown message type %d %s\n", type,
3919		       ceph_msg_type_name(type));
3920	}
3921out:
3922	ceph_msg_put(msg);
3923}
3924
3925/*
3926 * authentication
3927 */
3928
3929/*
3930 * Note: returned pointer is the address of a structure that's
3931 * managed separately.  Caller must *not* attempt to free it.
3932 */
3933static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3934					int *proto, int force_new)
3935{
3936	struct ceph_mds_session *s = con->private;
3937	struct ceph_mds_client *mdsc = s->s_mdsc;
3938	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3939	struct ceph_auth_handshake *auth = &s->s_auth;
3940
3941	if (force_new && auth->authorizer) {
3942		ceph_auth_destroy_authorizer(auth->authorizer);
3943		auth->authorizer = NULL;
3944	}
3945	if (!auth->authorizer) {
3946		int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3947						      auth);
3948		if (ret)
3949			return ERR_PTR(ret);
3950	} else {
3951		int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3952						      auth);
3953		if (ret)
3954			return ERR_PTR(ret);
3955	}
3956	*proto = ac->protocol;
3957
3958	return auth;
3959}
3960
 
 
 
 
 
 
 
 
 
 
3961
3962static int verify_authorizer_reply(struct ceph_connection *con)
3963{
3964	struct ceph_mds_session *s = con->private;
3965	struct ceph_mds_client *mdsc = s->s_mdsc;
3966	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3967
3968	return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
3969}
3970
3971static int invalidate_authorizer(struct ceph_connection *con)
3972{
3973	struct ceph_mds_session *s = con->private;
3974	struct ceph_mds_client *mdsc = s->s_mdsc;
3975	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3976
3977	ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3978
3979	return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3980}
3981
3982static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3983				struct ceph_msg_header *hdr, int *skip)
3984{
3985	struct ceph_msg *msg;
3986	int type = (int) le16_to_cpu(hdr->type);
3987	int front_len = (int) le32_to_cpu(hdr->front_len);
3988
3989	if (con->in_msg)
3990		return con->in_msg;
3991
3992	*skip = 0;
3993	msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3994	if (!msg) {
3995		pr_err("unable to allocate msg type %d len %d\n",
3996		       type, front_len);
3997		return NULL;
3998	}
3999
4000	return msg;
4001}
4002
4003static int mds_sign_message(struct ceph_msg *msg)
4004{
4005       struct ceph_mds_session *s = msg->con->private;
4006       struct ceph_auth_handshake *auth = &s->s_auth;
4007
4008       return ceph_auth_sign_message(auth, msg);
4009}
4010
4011static int mds_check_message_signature(struct ceph_msg *msg)
4012{
4013       struct ceph_mds_session *s = msg->con->private;
4014       struct ceph_auth_handshake *auth = &s->s_auth;
4015
4016       return ceph_auth_check_message_signature(auth, msg);
4017}
4018
4019static const struct ceph_connection_operations mds_con_ops = {
4020	.get = con_get,
4021	.put = con_put,
4022	.dispatch = dispatch,
4023	.get_authorizer = get_authorizer,
 
4024	.verify_authorizer_reply = verify_authorizer_reply,
4025	.invalidate_authorizer = invalidate_authorizer,
4026	.peer_reset = peer_reset,
4027	.alloc_msg = mds_alloc_msg,
4028	.sign_message = mds_sign_message,
4029	.check_message_signature = mds_check_message_signature,
4030};
4031
4032/* eof */