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#include <linux/bits.h>
  13#include <linux/ktime.h>
  14#include <linux/bitmap.h>
  15
  16#include "super.h"
  17#include "mds_client.h"
  18
  19#include <linux/ceph/ceph_features.h>
  20#include <linux/ceph/messenger.h>
  21#include <linux/ceph/decode.h>
  22#include <linux/ceph/pagelist.h>
  23#include <linux/ceph/auth.h>
  24#include <linux/ceph/debugfs.h>
  25
  26#define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  27
  28/*
  29 * A cluster of MDS (metadata server) daemons is responsible for
  30 * managing the file system namespace (the directory hierarchy and
  31 * inodes) and for coordinating shared access to storage.  Metadata is
  32 * partitioning hierarchically across a number of servers, and that
  33 * partition varies over time as the cluster adjusts the distribution
  34 * in order to balance load.
  35 *
  36 * The MDS client is primarily responsible to managing synchronous
  37 * metadata requests for operations like open, unlink, and so forth.
  38 * If there is a MDS failure, we find out about it when we (possibly
  39 * request and) receive a new MDS map, and can resubmit affected
  40 * requests.
  41 *
  42 * For the most part, though, we take advantage of a lossless
  43 * communications channel to the MDS, and do not need to worry about
  44 * timing out or resubmitting requests.
  45 *
  46 * We maintain a stateful "session" with each MDS we interact with.
  47 * Within each session, we sent periodic heartbeat messages to ensure
  48 * any capabilities or leases we have been issues remain valid.  If
  49 * the session times out and goes stale, our leases and capabilities
  50 * are no longer valid.
  51 */
  52
  53struct ceph_reconnect_state {
  54	struct ceph_mds_session *session;
  55	int nr_caps, nr_realms;
  56	struct ceph_pagelist *pagelist;
  57	unsigned msg_version;
  58	bool allow_multi;
  59};
  60
  61static void __wake_requests(struct ceph_mds_client *mdsc,
  62			    struct list_head *head);
  63static void ceph_cap_release_work(struct work_struct *work);
  64static void ceph_cap_reclaim_work(struct work_struct *work);
  65
  66static const struct ceph_connection_operations mds_con_ops;
  67
  68
  69/*
  70 * mds reply parsing
  71 */
  72
  73static int parse_reply_info_quota(void **p, void *end,
  74				  struct ceph_mds_reply_info_in *info)
  75{
  76	u8 struct_v, struct_compat;
  77	u32 struct_len;
  78
  79	ceph_decode_8_safe(p, end, struct_v, bad);
  80	ceph_decode_8_safe(p, end, struct_compat, bad);
  81	/* struct_v is expected to be >= 1. we only
  82	 * understand encoding with struct_compat == 1. */
  83	if (!struct_v || struct_compat != 1)
  84		goto bad;
  85	ceph_decode_32_safe(p, end, struct_len, bad);
  86	ceph_decode_need(p, end, struct_len, bad);
  87	end = *p + struct_len;
  88	ceph_decode_64_safe(p, end, info->max_bytes, bad);
  89	ceph_decode_64_safe(p, end, info->max_files, bad);
  90	*p = end;
  91	return 0;
  92bad:
  93	return -EIO;
  94}
  95
  96/*
  97 * parse individual inode info
  98 */
  99static int parse_reply_info_in(void **p, void *end,
 100			       struct ceph_mds_reply_info_in *info,
 101			       u64 features)
 102{
 103	int err = 0;
 104	u8 struct_v = 0;
 105
 106	if (features == (u64)-1) {
 107		u32 struct_len;
 108		u8 struct_compat;
 109		ceph_decode_8_safe(p, end, struct_v, bad);
 110		ceph_decode_8_safe(p, end, struct_compat, bad);
 111		/* struct_v is expected to be >= 1. we only understand
 112		 * encoding with struct_compat == 1. */
 113		if (!struct_v || struct_compat != 1)
 114			goto bad;
 115		ceph_decode_32_safe(p, end, struct_len, bad);
 116		ceph_decode_need(p, end, struct_len, bad);
 117		end = *p + struct_len;
 118	}
 119
 120	ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 121	info->in = *p;
 122	*p += sizeof(struct ceph_mds_reply_inode) +
 123		sizeof(*info->in->fragtree.splits) *
 124		le32_to_cpu(info->in->fragtree.nsplits);
 125
 126	ceph_decode_32_safe(p, end, info->symlink_len, bad);
 127	ceph_decode_need(p, end, info->symlink_len, bad);
 128	info->symlink = *p;
 129	*p += info->symlink_len;
 130
 131	ceph_decode_copy_safe(p, end, &info->dir_layout,
 132			      sizeof(info->dir_layout), bad);
 133	ceph_decode_32_safe(p, end, info->xattr_len, bad);
 134	ceph_decode_need(p, end, info->xattr_len, bad);
 135	info->xattr_data = *p;
 136	*p += info->xattr_len;
 137
 138	if (features == (u64)-1) {
 139		/* inline data */
 140		ceph_decode_64_safe(p, end, info->inline_version, bad);
 141		ceph_decode_32_safe(p, end, info->inline_len, bad);
 142		ceph_decode_need(p, end, info->inline_len, bad);
 143		info->inline_data = *p;
 144		*p += info->inline_len;
 145		/* quota */
 146		err = parse_reply_info_quota(p, end, info);
 147		if (err < 0)
 148			goto out_bad;
 149		/* pool namespace */
 150		ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 151		if (info->pool_ns_len > 0) {
 152			ceph_decode_need(p, end, info->pool_ns_len, bad);
 153			info->pool_ns_data = *p;
 154			*p += info->pool_ns_len;
 155		}
 156
 157		/* btime */
 158		ceph_decode_need(p, end, sizeof(info->btime), bad);
 159		ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 160
 161		/* change attribute */
 162		ceph_decode_64_safe(p, end, info->change_attr, bad);
 163
 164		/* dir pin */
 165		if (struct_v >= 2) {
 166			ceph_decode_32_safe(p, end, info->dir_pin, bad);
 167		} else {
 168			info->dir_pin = -ENODATA;
 169		}
 170
 171		/* snapshot birth time, remains zero for v<=2 */
 172		if (struct_v >= 3) {
 173			ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 174			ceph_decode_copy(p, &info->snap_btime,
 175					 sizeof(info->snap_btime));
 176		} else {
 177			memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 178		}
 179
 180		/* snapshot count, remains zero for v<=3 */
 181		if (struct_v >= 4) {
 182			ceph_decode_64_safe(p, end, info->rsnaps, bad);
 183		} else {
 184			info->rsnaps = 0;
 185		}
 186
 187		*p = end;
 188	} else {
 189		if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 190			ceph_decode_64_safe(p, end, info->inline_version, bad);
 191			ceph_decode_32_safe(p, end, info->inline_len, bad);
 192			ceph_decode_need(p, end, info->inline_len, bad);
 193			info->inline_data = *p;
 194			*p += info->inline_len;
 195		} else
 196			info->inline_version = CEPH_INLINE_NONE;
 197
 198		if (features & CEPH_FEATURE_MDS_QUOTA) {
 199			err = parse_reply_info_quota(p, end, info);
 200			if (err < 0)
 201				goto out_bad;
 202		} else {
 203			info->max_bytes = 0;
 204			info->max_files = 0;
 205		}
 206
 207		info->pool_ns_len = 0;
 208		info->pool_ns_data = NULL;
 209		if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 210			ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 211			if (info->pool_ns_len > 0) {
 212				ceph_decode_need(p, end, info->pool_ns_len, bad);
 213				info->pool_ns_data = *p;
 214				*p += info->pool_ns_len;
 215			}
 216		}
 217
 218		if (features & CEPH_FEATURE_FS_BTIME) {
 219			ceph_decode_need(p, end, sizeof(info->btime), bad);
 220			ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 221			ceph_decode_64_safe(p, end, info->change_attr, bad);
 222		}
 223
 224		info->dir_pin = -ENODATA;
 225		/* info->snap_btime and info->rsnaps remain zero */
 226	}
 227	return 0;
 228bad:
 229	err = -EIO;
 230out_bad:
 231	return err;
 232}
 233
 234static int parse_reply_info_dir(void **p, void *end,
 235				struct ceph_mds_reply_dirfrag **dirfrag,
 236				u64 features)
 237{
 238	if (features == (u64)-1) {
 239		u8 struct_v, struct_compat;
 240		u32 struct_len;
 241		ceph_decode_8_safe(p, end, struct_v, bad);
 242		ceph_decode_8_safe(p, end, struct_compat, bad);
 243		/* struct_v is expected to be >= 1. we only understand
 244		 * encoding whose struct_compat == 1. */
 245		if (!struct_v || struct_compat != 1)
 246			goto bad;
 247		ceph_decode_32_safe(p, end, struct_len, bad);
 248		ceph_decode_need(p, end, struct_len, bad);
 249		end = *p + struct_len;
 250	}
 251
 252	ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 253	*dirfrag = *p;
 254	*p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 255	if (unlikely(*p > end))
 256		goto bad;
 257	if (features == (u64)-1)
 258		*p = end;
 259	return 0;
 260bad:
 261	return -EIO;
 262}
 263
 264static int parse_reply_info_lease(void **p, void *end,
 265				  struct ceph_mds_reply_lease **lease,
 266				  u64 features)
 267{
 268	if (features == (u64)-1) {
 269		u8 struct_v, struct_compat;
 270		u32 struct_len;
 271		ceph_decode_8_safe(p, end, struct_v, bad);
 272		ceph_decode_8_safe(p, end, struct_compat, bad);
 273		/* struct_v is expected to be >= 1. we only understand
 274		 * encoding whose struct_compat == 1. */
 275		if (!struct_v || struct_compat != 1)
 276			goto bad;
 277		ceph_decode_32_safe(p, end, struct_len, bad);
 278		ceph_decode_need(p, end, struct_len, bad);
 279		end = *p + struct_len;
 280	}
 281
 282	ceph_decode_need(p, end, sizeof(**lease), bad);
 283	*lease = *p;
 284	*p += sizeof(**lease);
 285	if (features == (u64)-1)
 286		*p = end;
 287	return 0;
 288bad:
 289	return -EIO;
 290}
 291
 292/*
 293 * parse a normal reply, which may contain a (dir+)dentry and/or a
 294 * target inode.
 295 */
 296static int parse_reply_info_trace(void **p, void *end,
 297				  struct ceph_mds_reply_info_parsed *info,
 298				  u64 features)
 299{
 300	int err;
 301
 302	if (info->head->is_dentry) {
 303		err = parse_reply_info_in(p, end, &info->diri, features);
 304		if (err < 0)
 305			goto out_bad;
 306
 307		err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 308		if (err < 0)
 309			goto out_bad;
 310
 311		ceph_decode_32_safe(p, end, info->dname_len, bad);
 312		ceph_decode_need(p, end, info->dname_len, bad);
 313		info->dname = *p;
 314		*p += info->dname_len;
 315
 316		err = parse_reply_info_lease(p, end, &info->dlease, features);
 317		if (err < 0)
 318			goto out_bad;
 319	}
 320
 321	if (info->head->is_target) {
 322		err = parse_reply_info_in(p, end, &info->targeti, features);
 323		if (err < 0)
 324			goto out_bad;
 325	}
 326
 327	if (unlikely(*p != end))
 328		goto bad;
 329	return 0;
 330
 331bad:
 332	err = -EIO;
 333out_bad:
 334	pr_err("problem parsing mds trace %d\n", err);
 335	return err;
 336}
 337
 338/*
 339 * parse readdir results
 340 */
 341static int parse_reply_info_readdir(void **p, void *end,
 342				struct ceph_mds_reply_info_parsed *info,
 343				u64 features)
 344{
 345	u32 num, i = 0;
 346	int err;
 347
 348	err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 349	if (err < 0)
 350		goto out_bad;
 351
 352	ceph_decode_need(p, end, sizeof(num) + 2, bad);
 353	num = ceph_decode_32(p);
 354	{
 355		u16 flags = ceph_decode_16(p);
 356		info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 357		info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 358		info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 359		info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 360	}
 361	if (num == 0)
 362		goto done;
 363
 364	BUG_ON(!info->dir_entries);
 365	if ((unsigned long)(info->dir_entries + num) >
 366	    (unsigned long)info->dir_entries + info->dir_buf_size) {
 367		pr_err("dir contents are larger than expected\n");
 368		WARN_ON(1);
 369		goto bad;
 370	}
 371
 372	info->dir_nr = num;
 373	while (num) {
 374		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 375		/* dentry */
 376		ceph_decode_32_safe(p, end, rde->name_len, bad);
 377		ceph_decode_need(p, end, rde->name_len, bad);
 378		rde->name = *p;
 379		*p += rde->name_len;
 380		dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 381
 382		/* dentry lease */
 383		err = parse_reply_info_lease(p, end, &rde->lease, features);
 384		if (err)
 385			goto out_bad;
 386		/* inode */
 387		err = parse_reply_info_in(p, end, &rde->inode, features);
 388		if (err < 0)
 389			goto out_bad;
 390		/* ceph_readdir_prepopulate() will update it */
 391		rde->offset = 0;
 392		i++;
 393		num--;
 394	}
 395
 396done:
 397	/* Skip over any unrecognized fields */
 398	*p = end;
 399	return 0;
 400
 401bad:
 402	err = -EIO;
 403out_bad:
 404	pr_err("problem parsing dir contents %d\n", err);
 405	return err;
 406}
 407
 408/*
 409 * parse fcntl F_GETLK results
 410 */
 411static int parse_reply_info_filelock(void **p, void *end,
 412				     struct ceph_mds_reply_info_parsed *info,
 413				     u64 features)
 414{
 415	if (*p + sizeof(*info->filelock_reply) > end)
 416		goto bad;
 417
 418	info->filelock_reply = *p;
 419
 420	/* Skip over any unrecognized fields */
 421	*p = end;
 422	return 0;
 423bad:
 424	return -EIO;
 425}
 426
 427
 428#if BITS_PER_LONG == 64
 429
 430#define DELEGATED_INO_AVAILABLE		xa_mk_value(1)
 431
 432static int ceph_parse_deleg_inos(void **p, void *end,
 433				 struct ceph_mds_session *s)
 434{
 435	u32 sets;
 436
 437	ceph_decode_32_safe(p, end, sets, bad);
 438	dout("got %u sets of delegated inodes\n", sets);
 439	while (sets--) {
 440		u64 start, len;
 441
 442		ceph_decode_64_safe(p, end, start, bad);
 443		ceph_decode_64_safe(p, end, len, bad);
 444
 445		/* Don't accept a delegation of system inodes */
 446		if (start < CEPH_INO_SYSTEM_BASE) {
 447			pr_warn_ratelimited("ceph: ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n",
 448					start, len);
 449			continue;
 450		}
 451		while (len--) {
 452			int err = xa_insert(&s->s_delegated_inos, start++,
 453					    DELEGATED_INO_AVAILABLE,
 454					    GFP_KERNEL);
 455			if (!err) {
 456				dout("added delegated inode 0x%llx\n",
 457				     start - 1);
 458			} else if (err == -EBUSY) {
 459				pr_warn("MDS delegated inode 0x%llx more than once.\n",
 460					start - 1);
 461			} else {
 462				return err;
 463			}
 464		}
 465	}
 466	return 0;
 467bad:
 468	return -EIO;
 469}
 470
 471u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 472{
 473	unsigned long ino;
 474	void *val;
 475
 476	xa_for_each(&s->s_delegated_inos, ino, val) {
 477		val = xa_erase(&s->s_delegated_inos, ino);
 478		if (val == DELEGATED_INO_AVAILABLE)
 479			return ino;
 480	}
 481	return 0;
 482}
 483
 484int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 485{
 486	return xa_insert(&s->s_delegated_inos, ino, DELEGATED_INO_AVAILABLE,
 487			 GFP_KERNEL);
 488}
 489#else /* BITS_PER_LONG == 64 */
 490/*
 491 * FIXME: xarrays can't handle 64-bit indexes on a 32-bit arch. For now, just
 492 * ignore delegated_inos on 32 bit arch. Maybe eventually add xarrays for top
 493 * and bottom words?
 494 */
 495static int ceph_parse_deleg_inos(void **p, void *end,
 496				 struct ceph_mds_session *s)
 497{
 498	u32 sets;
 499
 500	ceph_decode_32_safe(p, end, sets, bad);
 501	if (sets)
 502		ceph_decode_skip_n(p, end, sets * 2 * sizeof(__le64), bad);
 503	return 0;
 504bad:
 505	return -EIO;
 506}
 507
 508u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 509{
 510	return 0;
 511}
 512
 513int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 514{
 515	return 0;
 516}
 517#endif /* BITS_PER_LONG == 64 */
 518
 519/*
 520 * parse create results
 521 */
 522static int parse_reply_info_create(void **p, void *end,
 523				  struct ceph_mds_reply_info_parsed *info,
 524				  u64 features, struct ceph_mds_session *s)
 525{
 526	int ret;
 527
 528	if (features == (u64)-1 ||
 529	    (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 530		if (*p == end) {
 531			/* Malformed reply? */
 532			info->has_create_ino = false;
 533		} else if (test_bit(CEPHFS_FEATURE_DELEG_INO, &s->s_features)) {
 534			info->has_create_ino = true;
 535			/* struct_v, struct_compat, and len */
 536			ceph_decode_skip_n(p, end, 2 + sizeof(u32), bad);
 537			ceph_decode_64_safe(p, end, info->ino, bad);
 538			ret = ceph_parse_deleg_inos(p, end, s);
 539			if (ret)
 540				return ret;
 541		} else {
 542			/* legacy */
 543			ceph_decode_64_safe(p, end, info->ino, bad);
 544			info->has_create_ino = true;
 545		}
 546	} else {
 547		if (*p != end)
 548			goto bad;
 549	}
 550
 551	/* Skip over any unrecognized fields */
 552	*p = end;
 553	return 0;
 554bad:
 555	return -EIO;
 556}
 557
 558static int parse_reply_info_getvxattr(void **p, void *end,
 559				      struct ceph_mds_reply_info_parsed *info,
 560				      u64 features)
 561{
 562	u32 value_len;
 563
 564	ceph_decode_skip_8(p, end, bad); /* skip current version: 1 */
 565	ceph_decode_skip_8(p, end, bad); /* skip first version: 1 */
 566	ceph_decode_skip_32(p, end, bad); /* skip payload length */
 567
 568	ceph_decode_32_safe(p, end, value_len, bad);
 569
 570	if (value_len == end - *p) {
 571	  info->xattr_info.xattr_value = *p;
 572	  info->xattr_info.xattr_value_len = value_len;
 573	  *p = end;
 574	  return value_len;
 575	}
 576bad:
 577	return -EIO;
 578}
 579
 580/*
 581 * parse extra results
 582 */
 583static int parse_reply_info_extra(void **p, void *end,
 584				  struct ceph_mds_reply_info_parsed *info,
 585				  u64 features, struct ceph_mds_session *s)
 586{
 587	u32 op = le32_to_cpu(info->head->op);
 588
 589	if (op == CEPH_MDS_OP_GETFILELOCK)
 590		return parse_reply_info_filelock(p, end, info, features);
 591	else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 592		return parse_reply_info_readdir(p, end, info, features);
 593	else if (op == CEPH_MDS_OP_CREATE)
 594		return parse_reply_info_create(p, end, info, features, s);
 595	else if (op == CEPH_MDS_OP_GETVXATTR)
 596		return parse_reply_info_getvxattr(p, end, info, features);
 597	else
 598		return -EIO;
 599}
 600
 601/*
 602 * parse entire mds reply
 603 */
 604static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
 605			    struct ceph_mds_reply_info_parsed *info,
 606			    u64 features)
 607{
 608	void *p, *end;
 609	u32 len;
 610	int err;
 611
 612	info->head = msg->front.iov_base;
 613	p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 614	end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 615
 616	/* trace */
 617	ceph_decode_32_safe(&p, end, len, bad);
 618	if (len > 0) {
 619		ceph_decode_need(&p, end, len, bad);
 620		err = parse_reply_info_trace(&p, p+len, info, features);
 621		if (err < 0)
 622			goto out_bad;
 623	}
 624
 625	/* extra */
 626	ceph_decode_32_safe(&p, end, len, bad);
 627	if (len > 0) {
 628		ceph_decode_need(&p, end, len, bad);
 629		err = parse_reply_info_extra(&p, p+len, info, features, s);
 630		if (err < 0)
 631			goto out_bad;
 632	}
 633
 634	/* snap blob */
 635	ceph_decode_32_safe(&p, end, len, bad);
 636	info->snapblob_len = len;
 637	info->snapblob = p;
 638	p += len;
 639
 640	if (p != end)
 641		goto bad;
 642	return 0;
 643
 644bad:
 645	err = -EIO;
 646out_bad:
 647	pr_err("mds parse_reply err %d\n", err);
 648	return err;
 649}
 650
 651static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 652{
 653	if (!info->dir_entries)
 654		return;
 655	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 656}
 657
 658/*
 659 * In async unlink case the kclient won't wait for the first reply
 660 * from MDS and just drop all the links and unhash the dentry and then
 661 * succeeds immediately.
 662 *
 663 * For any new create/link/rename,etc requests followed by using the
 664 * same file names we must wait for the first reply of the inflight
 665 * unlink request, or the MDS possibly will fail these following
 666 * requests with -EEXIST if the inflight async unlink request was
 667 * delayed for some reasons.
 668 *
 669 * And the worst case is that for the none async openc request it will
 670 * successfully open the file if the CDentry hasn't been unlinked yet,
 671 * but later the previous delayed async unlink request will remove the
 672 * CDenty. That means the just created file is possiblly deleted later
 673 * by accident.
 674 *
 675 * We need to wait for the inflight async unlink requests to finish
 676 * when creating new files/directories by using the same file names.
 677 */
 678int ceph_wait_on_conflict_unlink(struct dentry *dentry)
 679{
 680	struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 681	struct dentry *pdentry = dentry->d_parent;
 682	struct dentry *udentry, *found = NULL;
 683	struct ceph_dentry_info *di;
 684	struct qstr dname;
 685	u32 hash = dentry->d_name.hash;
 686	int err;
 687
 688	dname.name = dentry->d_name.name;
 689	dname.len = dentry->d_name.len;
 690
 691	rcu_read_lock();
 692	hash_for_each_possible_rcu(fsc->async_unlink_conflict, di,
 693				   hnode, hash) {
 694		udentry = di->dentry;
 695
 696		spin_lock(&udentry->d_lock);
 697		if (udentry->d_name.hash != hash)
 698			goto next;
 699		if (unlikely(udentry->d_parent != pdentry))
 700			goto next;
 701		if (!hash_hashed(&di->hnode))
 702			goto next;
 703
 704		if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
 705			pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
 706				__func__, dentry, dentry);
 707
 708		if (!d_same_name(udentry, pdentry, &dname))
 709			goto next;
 710
 711		spin_unlock(&udentry->d_lock);
 712		found = dget(udentry);
 713		break;
 714next:
 715		spin_unlock(&udentry->d_lock);
 716	}
 717	rcu_read_unlock();
 718
 719	if (likely(!found))
 720		return 0;
 721
 722	dout("%s dentry %p:%pd conflict with old %p:%pd\n", __func__,
 723	     dentry, dentry, found, found);
 724
 725	err = wait_on_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT,
 726			  TASK_KILLABLE);
 727	dput(found);
 728	return err;
 729}
 730
 731
 732/*
 733 * sessions
 734 */
 735const char *ceph_session_state_name(int s)
 736{
 737	switch (s) {
 738	case CEPH_MDS_SESSION_NEW: return "new";
 739	case CEPH_MDS_SESSION_OPENING: return "opening";
 740	case CEPH_MDS_SESSION_OPEN: return "open";
 741	case CEPH_MDS_SESSION_HUNG: return "hung";
 742	case CEPH_MDS_SESSION_CLOSING: return "closing";
 743	case CEPH_MDS_SESSION_CLOSED: return "closed";
 744	case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 745	case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 746	case CEPH_MDS_SESSION_REJECTED: return "rejected";
 747	default: return "???";
 748	}
 749}
 750
 751struct ceph_mds_session *ceph_get_mds_session(struct ceph_mds_session *s)
 752{
 753	if (refcount_inc_not_zero(&s->s_ref))
 
 
 754		return s;
 755	return NULL;
 
 
 
 756}
 757
 758void ceph_put_mds_session(struct ceph_mds_session *s)
 759{
 760	if (IS_ERR_OR_NULL(s))
 761		return;
 762
 
 
 763	if (refcount_dec_and_test(&s->s_ref)) {
 764		if (s->s_auth.authorizer)
 765			ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 766		WARN_ON(mutex_is_locked(&s->s_mutex));
 767		xa_destroy(&s->s_delegated_inos);
 768		kfree(s);
 769	}
 770}
 771
 772/*
 773 * called under mdsc->mutex
 774 */
 775struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 776						   int mds)
 777{
 778	if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 779		return NULL;
 780	return ceph_get_mds_session(mdsc->sessions[mds]);
 781}
 782
 783static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 784{
 785	if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 786		return false;
 787	else
 788		return true;
 789}
 790
 791static int __verify_registered_session(struct ceph_mds_client *mdsc,
 792				       struct ceph_mds_session *s)
 793{
 794	if (s->s_mds >= mdsc->max_sessions ||
 795	    mdsc->sessions[s->s_mds] != s)
 796		return -ENOENT;
 797	return 0;
 798}
 799
 800/*
 801 * create+register a new session for given mds.
 802 * called under mdsc->mutex.
 803 */
 804static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 805						 int mds)
 806{
 807	struct ceph_mds_session *s;
 808
 809	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_FENCE_IO)
 810		return ERR_PTR(-EIO);
 811
 812	if (mds >= mdsc->mdsmap->possible_max_rank)
 813		return ERR_PTR(-EINVAL);
 814
 815	s = kzalloc(sizeof(*s), GFP_NOFS);
 816	if (!s)
 817		return ERR_PTR(-ENOMEM);
 818
 819	if (mds >= mdsc->max_sessions) {
 820		int newmax = 1 << get_count_order(mds + 1);
 821		struct ceph_mds_session **sa;
 822
 823		dout("%s: realloc to %d\n", __func__, newmax);
 824		sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 825		if (!sa)
 826			goto fail_realloc;
 827		if (mdsc->sessions) {
 828			memcpy(sa, mdsc->sessions,
 829			       mdsc->max_sessions * sizeof(void *));
 830			kfree(mdsc->sessions);
 831		}
 832		mdsc->sessions = sa;
 833		mdsc->max_sessions = newmax;
 834	}
 835
 836	dout("%s: mds%d\n", __func__, mds);
 837	s->s_mdsc = mdsc;
 838	s->s_mds = mds;
 839	s->s_state = CEPH_MDS_SESSION_NEW;
 
 
 840	mutex_init(&s->s_mutex);
 841
 842	ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 843
 844	atomic_set(&s->s_cap_gen, 1);
 845	s->s_cap_ttl = jiffies - 1;
 846
 847	spin_lock_init(&s->s_cap_lock);
 
 
 848	INIT_LIST_HEAD(&s->s_caps);
 
 849	refcount_set(&s->s_ref, 1);
 850	INIT_LIST_HEAD(&s->s_waiting);
 851	INIT_LIST_HEAD(&s->s_unsafe);
 852	xa_init(&s->s_delegated_inos);
 
 
 
 853	INIT_LIST_HEAD(&s->s_cap_releases);
 854	INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 855
 856	INIT_LIST_HEAD(&s->s_cap_dirty);
 857	INIT_LIST_HEAD(&s->s_cap_flushing);
 858
 859	mdsc->sessions[mds] = s;
 860	atomic_inc(&mdsc->num_sessions);
 861	refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 862
 863	ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 864		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 865
 866	return s;
 867
 868fail_realloc:
 869	kfree(s);
 870	return ERR_PTR(-ENOMEM);
 871}
 872
 873/*
 874 * called under mdsc->mutex
 875 */
 876static void __unregister_session(struct ceph_mds_client *mdsc,
 877			       struct ceph_mds_session *s)
 878{
 879	dout("__unregister_session mds%d %p\n", s->s_mds, s);
 880	BUG_ON(mdsc->sessions[s->s_mds] != s);
 881	mdsc->sessions[s->s_mds] = NULL;
 882	ceph_con_close(&s->s_con);
 883	ceph_put_mds_session(s);
 884	atomic_dec(&mdsc->num_sessions);
 885}
 886
 887/*
 888 * drop session refs in request.
 889 *
 890 * should be last request ref, or hold mdsc->mutex
 891 */
 892static void put_request_session(struct ceph_mds_request *req)
 893{
 894	if (req->r_session) {
 895		ceph_put_mds_session(req->r_session);
 896		req->r_session = NULL;
 897	}
 898}
 899
 900void ceph_mdsc_iterate_sessions(struct ceph_mds_client *mdsc,
 901				void (*cb)(struct ceph_mds_session *),
 902				bool check_state)
 903{
 904	int mds;
 905
 906	mutex_lock(&mdsc->mutex);
 907	for (mds = 0; mds < mdsc->max_sessions; ++mds) {
 908		struct ceph_mds_session *s;
 909
 910		s = __ceph_lookup_mds_session(mdsc, mds);
 911		if (!s)
 912			continue;
 913
 914		if (check_state && !check_session_state(s)) {
 915			ceph_put_mds_session(s);
 916			continue;
 917		}
 918
 919		mutex_unlock(&mdsc->mutex);
 920		cb(s);
 921		ceph_put_mds_session(s);
 922		mutex_lock(&mdsc->mutex);
 923	}
 924	mutex_unlock(&mdsc->mutex);
 925}
 926
 927void ceph_mdsc_release_request(struct kref *kref)
 928{
 929	struct ceph_mds_request *req = container_of(kref,
 930						    struct ceph_mds_request,
 931						    r_kref);
 932	ceph_mdsc_release_dir_caps_no_check(req);
 933	destroy_reply_info(&req->r_reply_info);
 934	if (req->r_request)
 935		ceph_msg_put(req->r_request);
 936	if (req->r_reply)
 937		ceph_msg_put(req->r_reply);
 938	if (req->r_inode) {
 939		ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 940		iput(req->r_inode);
 941	}
 942	if (req->r_parent) {
 943		ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 944		iput(req->r_parent);
 945	}
 946	iput(req->r_target_inode);
 947	if (req->r_dentry)
 948		dput(req->r_dentry);
 949	if (req->r_old_dentry)
 950		dput(req->r_old_dentry);
 951	if (req->r_old_dentry_dir) {
 952		/*
 953		 * track (and drop pins for) r_old_dentry_dir
 954		 * separately, since r_old_dentry's d_parent may have
 955		 * changed between the dir mutex being dropped and
 956		 * this request being freed.
 957		 */
 958		ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 959				  CEPH_CAP_PIN);
 960		iput(req->r_old_dentry_dir);
 961	}
 962	kfree(req->r_path1);
 963	kfree(req->r_path2);
 964	put_cred(req->r_cred);
 965	if (req->r_pagelist)
 966		ceph_pagelist_release(req->r_pagelist);
 967	put_request_session(req);
 968	ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 969	WARN_ON_ONCE(!list_empty(&req->r_wait));
 970	kmem_cache_free(ceph_mds_request_cachep, req);
 971}
 972
 973DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 974
 975/*
 976 * lookup session, bump ref if found.
 977 *
 978 * called under mdsc->mutex.
 979 */
 980static struct ceph_mds_request *
 981lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 982{
 983	struct ceph_mds_request *req;
 984
 985	req = lookup_request(&mdsc->request_tree, tid);
 986	if (req)
 987		ceph_mdsc_get_request(req);
 988
 989	return req;
 990}
 991
 992/*
 993 * Register an in-flight request, and assign a tid.  Link to directory
 994 * are modifying (if any).
 995 *
 996 * Called under mdsc->mutex.
 997 */
 998static void __register_request(struct ceph_mds_client *mdsc,
 999			       struct ceph_mds_request *req,
1000			       struct inode *dir)
1001{
1002	int ret = 0;
1003
1004	req->r_tid = ++mdsc->last_tid;
1005	if (req->r_num_caps) {
1006		ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
1007					req->r_num_caps);
1008		if (ret < 0) {
1009			pr_err("__register_request %p "
1010			       "failed to reserve caps: %d\n", req, ret);
1011			/* set req->r_err to fail early from __do_request */
1012			req->r_err = ret;
1013			return;
1014		}
1015	}
1016	dout("__register_request %p tid %lld\n", req, req->r_tid);
1017	ceph_mdsc_get_request(req);
1018	insert_request(&mdsc->request_tree, req);
1019
1020	req->r_cred = get_current_cred();
1021
1022	if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
1023		mdsc->oldest_tid = req->r_tid;
1024
1025	if (dir) {
1026		struct ceph_inode_info *ci = ceph_inode(dir);
1027
1028		ihold(dir);
1029		req->r_unsafe_dir = dir;
1030		spin_lock(&ci->i_unsafe_lock);
1031		list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
1032		spin_unlock(&ci->i_unsafe_lock);
1033	}
1034}
1035
1036static void __unregister_request(struct ceph_mds_client *mdsc,
1037				 struct ceph_mds_request *req)
1038{
1039	dout("__unregister_request %p tid %lld\n", req, req->r_tid);
1040
1041	/* Never leave an unregistered request on an unsafe list! */
1042	list_del_init(&req->r_unsafe_item);
1043
1044	if (req->r_tid == mdsc->oldest_tid) {
1045		struct rb_node *p = rb_next(&req->r_node);
1046		mdsc->oldest_tid = 0;
1047		while (p) {
1048			struct ceph_mds_request *next_req =
1049				rb_entry(p, struct ceph_mds_request, r_node);
1050			if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
1051				mdsc->oldest_tid = next_req->r_tid;
1052				break;
1053			}
1054			p = rb_next(p);
1055		}
1056	}
1057
1058	erase_request(&mdsc->request_tree, req);
1059
1060	if (req->r_unsafe_dir) {
1061		struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
1062		spin_lock(&ci->i_unsafe_lock);
1063		list_del_init(&req->r_unsafe_dir_item);
1064		spin_unlock(&ci->i_unsafe_lock);
1065	}
1066	if (req->r_target_inode &&
1067	    test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
1068		struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
1069		spin_lock(&ci->i_unsafe_lock);
1070		list_del_init(&req->r_unsafe_target_item);
1071		spin_unlock(&ci->i_unsafe_lock);
1072	}
1073
1074	if (req->r_unsafe_dir) {
1075		iput(req->r_unsafe_dir);
1076		req->r_unsafe_dir = NULL;
1077	}
1078
1079	complete_all(&req->r_safe_completion);
1080
1081	ceph_mdsc_put_request(req);
1082}
1083
1084/*
1085 * Walk back up the dentry tree until we hit a dentry representing a
1086 * non-snapshot inode. We do this using the rcu_read_lock (which must be held
1087 * when calling this) to ensure that the objects won't disappear while we're
1088 * working with them. Once we hit a candidate dentry, we attempt to take a
1089 * reference to it, and return that as the result.
1090 */
1091static struct inode *get_nonsnap_parent(struct dentry *dentry)
1092{
1093	struct inode *inode = NULL;
1094
1095	while (dentry && !IS_ROOT(dentry)) {
1096		inode = d_inode_rcu(dentry);
1097		if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
1098			break;
1099		dentry = dentry->d_parent;
1100	}
1101	if (inode)
1102		inode = igrab(inode);
1103	return inode;
1104}
1105
1106/*
1107 * Choose mds to send request to next.  If there is a hint set in the
1108 * request (e.g., due to a prior forward hint from the mds), use that.
1109 * Otherwise, consult frag tree and/or caps to identify the
1110 * appropriate mds.  If all else fails, choose randomly.
1111 *
1112 * Called under mdsc->mutex.
1113 */
1114static int __choose_mds(struct ceph_mds_client *mdsc,
1115			struct ceph_mds_request *req,
1116			bool *random)
1117{
1118	struct inode *inode;
1119	struct ceph_inode_info *ci;
1120	struct ceph_cap *cap;
1121	int mode = req->r_direct_mode;
1122	int mds = -1;
1123	u32 hash = req->r_direct_hash;
1124	bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
1125
1126	if (random)
1127		*random = false;
1128
1129	/*
1130	 * is there a specific mds we should try?  ignore hint if we have
1131	 * no session and the mds is not up (active or recovering).
1132	 */
1133	if (req->r_resend_mds >= 0 &&
1134	    (__have_session(mdsc, req->r_resend_mds) ||
1135	     ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
1136		dout("%s using resend_mds mds%d\n", __func__,
1137		     req->r_resend_mds);
1138		return req->r_resend_mds;
1139	}
1140
1141	if (mode == USE_RANDOM_MDS)
1142		goto random;
1143
1144	inode = NULL;
1145	if (req->r_inode) {
1146		if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
1147			inode = req->r_inode;
1148			ihold(inode);
1149		} else {
1150			/* req->r_dentry is non-null for LSSNAP request */
1151			rcu_read_lock();
1152			inode = get_nonsnap_parent(req->r_dentry);
1153			rcu_read_unlock();
1154			dout("%s using snapdir's parent %p\n", __func__, inode);
1155		}
1156	} else if (req->r_dentry) {
1157		/* ignore race with rename; old or new d_parent is okay */
1158		struct dentry *parent;
1159		struct inode *dir;
1160
1161		rcu_read_lock();
1162		parent = READ_ONCE(req->r_dentry->d_parent);
1163		dir = req->r_parent ? : d_inode_rcu(parent);
1164
1165		if (!dir || dir->i_sb != mdsc->fsc->sb) {
1166			/*  not this fs or parent went negative */
1167			inode = d_inode(req->r_dentry);
1168			if (inode)
1169				ihold(inode);
1170		} else if (ceph_snap(dir) != CEPH_NOSNAP) {
1171			/* direct snapped/virtual snapdir requests
1172			 * based on parent dir inode */
1173			inode = get_nonsnap_parent(parent);
1174			dout("%s using nonsnap parent %p\n", __func__, inode);
1175		} else {
1176			/* dentry target */
1177			inode = d_inode(req->r_dentry);
1178			if (!inode || mode == USE_AUTH_MDS) {
1179				/* dir + name */
1180				inode = igrab(dir);
1181				hash = ceph_dentry_hash(dir, req->r_dentry);
1182				is_hash = true;
1183			} else {
1184				ihold(inode);
1185			}
1186		}
1187		rcu_read_unlock();
1188	}
1189
1190	dout("%s %p is_hash=%d (0x%x) mode %d\n", __func__, inode, (int)is_hash,
1191	     hash, mode);
1192	if (!inode)
1193		goto random;
1194	ci = ceph_inode(inode);
1195
1196	if (is_hash && S_ISDIR(inode->i_mode)) {
1197		struct ceph_inode_frag frag;
1198		int found;
1199
1200		ceph_choose_frag(ci, hash, &frag, &found);
1201		if (found) {
1202			if (mode == USE_ANY_MDS && frag.ndist > 0) {
1203				u8 r;
1204
1205				/* choose a random replica */
1206				get_random_bytes(&r, 1);
1207				r %= frag.ndist;
1208				mds = frag.dist[r];
1209				dout("%s %p %llx.%llx frag %u mds%d (%d/%d)\n",
1210				     __func__, inode, ceph_vinop(inode),
1211				     frag.frag, mds, (int)r, frag.ndist);
1212				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1213				    CEPH_MDS_STATE_ACTIVE &&
1214				    !ceph_mdsmap_is_laggy(mdsc->mdsmap, mds))
1215					goto out;
1216			}
1217
1218			/* since this file/dir wasn't known to be
1219			 * replicated, then we want to look for the
1220			 * authoritative mds. */
1221			if (frag.mds >= 0) {
1222				/* choose auth mds */
1223				mds = frag.mds;
1224				dout("%s %p %llx.%llx frag %u mds%d (auth)\n",
1225				     __func__, inode, ceph_vinop(inode),
1226				     frag.frag, mds);
1227				if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1228				    CEPH_MDS_STATE_ACTIVE) {
1229					if (!ceph_mdsmap_is_laggy(mdsc->mdsmap,
1230								  mds))
1231						goto out;
1232				}
1233			}
1234			mode = USE_AUTH_MDS;
1235		}
1236	}
1237
1238	spin_lock(&ci->i_ceph_lock);
1239	cap = NULL;
1240	if (mode == USE_AUTH_MDS)
1241		cap = ci->i_auth_cap;
1242	if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1243		cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1244	if (!cap) {
1245		spin_unlock(&ci->i_ceph_lock);
1246		iput(inode);
1247		goto random;
1248	}
1249	mds = cap->session->s_mds;
1250	dout("%s %p %llx.%llx mds%d (%scap %p)\n", __func__,
1251	     inode, ceph_vinop(inode), mds,
1252	     cap == ci->i_auth_cap ? "auth " : "", cap);
1253	spin_unlock(&ci->i_ceph_lock);
1254out:
1255	iput(inode);
1256	return mds;
1257
1258random:
1259	if (random)
1260		*random = true;
1261
1262	mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1263	dout("%s chose random mds%d\n", __func__, mds);
1264	return mds;
1265}
1266
1267
1268/*
1269 * session messages
1270 */
1271struct ceph_msg *ceph_create_session_msg(u32 op, u64 seq)
1272{
1273	struct ceph_msg *msg;
1274	struct ceph_mds_session_head *h;
1275
1276	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1277			   false);
1278	if (!msg) {
1279		pr_err("ENOMEM creating session %s msg\n",
1280		       ceph_session_op_name(op));
1281		return NULL;
1282	}
1283	h = msg->front.iov_base;
1284	h->op = cpu_to_le32(op);
1285	h->seq = cpu_to_le64(seq);
1286
1287	return msg;
1288}
1289
1290static const unsigned char feature_bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1291#define FEATURE_BYTES(c) (DIV_ROUND_UP((size_t)feature_bits[c - 1] + 1, 64) * 8)
1292static int encode_supported_features(void **p, void *end)
1293{
1294	static const size_t count = ARRAY_SIZE(feature_bits);
1295
1296	if (count > 0) {
1297		size_t i;
1298		size_t size = FEATURE_BYTES(count);
1299		unsigned long bit;
1300
1301		if (WARN_ON_ONCE(*p + 4 + size > end))
1302			return -ERANGE;
1303
1304		ceph_encode_32(p, size);
1305		memset(*p, 0, size);
1306		for (i = 0; i < count; i++) {
1307			bit = feature_bits[i];
1308			((unsigned char *)(*p))[bit / 8] |= BIT(bit % 8);
1309		}
1310		*p += size;
1311	} else {
1312		if (WARN_ON_ONCE(*p + 4 > end))
1313			return -ERANGE;
1314
1315		ceph_encode_32(p, 0);
1316	}
1317
1318	return 0;
1319}
1320
1321static const unsigned char metric_bits[] = CEPHFS_METRIC_SPEC_CLIENT_SUPPORTED;
1322#define METRIC_BYTES(cnt) (DIV_ROUND_UP((size_t)metric_bits[cnt - 1] + 1, 64) * 8)
1323static int encode_metric_spec(void **p, void *end)
1324{
1325	static const size_t count = ARRAY_SIZE(metric_bits);
1326
1327	/* header */
1328	if (WARN_ON_ONCE(*p + 2 > end))
1329		return -ERANGE;
1330
1331	ceph_encode_8(p, 1); /* version */
1332	ceph_encode_8(p, 1); /* compat */
1333
1334	if (count > 0) {
1335		size_t i;
1336		size_t size = METRIC_BYTES(count);
1337
1338		if (WARN_ON_ONCE(*p + 4 + 4 + size > end))
1339			return -ERANGE;
1340
1341		/* metric spec info length */
1342		ceph_encode_32(p, 4 + size);
1343
1344		/* metric spec */
1345		ceph_encode_32(p, size);
1346		memset(*p, 0, size);
1347		for (i = 0; i < count; i++)
1348			((unsigned char *)(*p))[i / 8] |= BIT(metric_bits[i] % 8);
1349		*p += size;
1350	} else {
1351		if (WARN_ON_ONCE(*p + 4 + 4 > end))
1352			return -ERANGE;
1353
1354		/* metric spec info length */
1355		ceph_encode_32(p, 4);
1356		/* metric spec */
1357		ceph_encode_32(p, 0);
1358	}
1359
1360	return 0;
1361}
1362
1363/*
1364 * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1365 * to include additional client metadata fields.
1366 */
1367static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1368{
1369	struct ceph_msg *msg;
1370	struct ceph_mds_session_head *h;
1371	int i;
1372	int extra_bytes = 0;
1373	int metadata_key_count = 0;
1374	struct ceph_options *opt = mdsc->fsc->client->options;
1375	struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1376	size_t size, count;
1377	void *p, *end;
1378	int ret;
1379
1380	const char* metadata[][2] = {
1381		{"hostname", mdsc->nodename},
1382		{"kernel_version", init_utsname()->release},
1383		{"entity_id", opt->name ? : ""},
1384		{"root", fsopt->server_path ? : "/"},
1385		{NULL, NULL}
1386	};
1387
1388	/* Calculate serialized length of metadata */
1389	extra_bytes = 4;  /* map length */
1390	for (i = 0; metadata[i][0]; ++i) {
1391		extra_bytes += 8 + strlen(metadata[i][0]) +
1392			strlen(metadata[i][1]);
1393		metadata_key_count++;
1394	}
1395
1396	/* supported feature */
1397	size = 0;
1398	count = ARRAY_SIZE(feature_bits);
1399	if (count > 0)
1400		size = FEATURE_BYTES(count);
1401	extra_bytes += 4 + size;
1402
1403	/* metric spec */
1404	size = 0;
1405	count = ARRAY_SIZE(metric_bits);
1406	if (count > 0)
1407		size = METRIC_BYTES(count);
1408	extra_bytes += 2 + 4 + 4 + size;
1409
1410	/* Allocate the message */
1411	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1412			   GFP_NOFS, false);
1413	if (!msg) {
1414		pr_err("ENOMEM creating session open msg\n");
1415		return ERR_PTR(-ENOMEM);
1416	}
1417	p = msg->front.iov_base;
1418	end = p + msg->front.iov_len;
1419
1420	h = p;
1421	h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1422	h->seq = cpu_to_le64(seq);
1423
1424	/*
1425	 * Serialize client metadata into waiting buffer space, using
1426	 * the format that userspace expects for map<string, string>
1427	 *
1428	 * ClientSession messages with metadata are v4
1429	 */
1430	msg->hdr.version = cpu_to_le16(4);
1431	msg->hdr.compat_version = cpu_to_le16(1);
1432
1433	/* The write pointer, following the session_head structure */
1434	p += sizeof(*h);
1435
1436	/* Number of entries in the map */
1437	ceph_encode_32(&p, metadata_key_count);
1438
1439	/* Two length-prefixed strings for each entry in the map */
1440	for (i = 0; metadata[i][0]; ++i) {
1441		size_t const key_len = strlen(metadata[i][0]);
1442		size_t const val_len = strlen(metadata[i][1]);
1443
1444		ceph_encode_32(&p, key_len);
1445		memcpy(p, metadata[i][0], key_len);
1446		p += key_len;
1447		ceph_encode_32(&p, val_len);
1448		memcpy(p, metadata[i][1], val_len);
1449		p += val_len;
1450	}
1451
1452	ret = encode_supported_features(&p, end);
1453	if (ret) {
1454		pr_err("encode_supported_features failed!\n");
1455		ceph_msg_put(msg);
1456		return ERR_PTR(ret);
1457	}
1458
1459	ret = encode_metric_spec(&p, end);
1460	if (ret) {
1461		pr_err("encode_metric_spec failed!\n");
1462		ceph_msg_put(msg);
1463		return ERR_PTR(ret);
1464	}
1465
1466	msg->front.iov_len = p - msg->front.iov_base;
1467	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1468
1469	return msg;
1470}
1471
1472/*
1473 * send session open request.
1474 *
1475 * called under mdsc->mutex
1476 */
1477static int __open_session(struct ceph_mds_client *mdsc,
1478			  struct ceph_mds_session *session)
1479{
1480	struct ceph_msg *msg;
1481	int mstate;
1482	int mds = session->s_mds;
1483
1484	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_FENCE_IO)
1485		return -EIO;
1486
1487	/* wait for mds to go active? */
1488	mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1489	dout("open_session to mds%d (%s)\n", mds,
1490	     ceph_mds_state_name(mstate));
1491	session->s_state = CEPH_MDS_SESSION_OPENING;
1492	session->s_renew_requested = jiffies;
1493
1494	/* send connect message */
1495	msg = create_session_open_msg(mdsc, session->s_seq);
1496	if (IS_ERR(msg))
1497		return PTR_ERR(msg);
1498	ceph_con_send(&session->s_con, msg);
1499	return 0;
1500}
1501
1502/*
1503 * open sessions for any export targets for the given mds
1504 *
1505 * called under mdsc->mutex
1506 */
1507static struct ceph_mds_session *
1508__open_export_target_session(struct ceph_mds_client *mdsc, int target)
1509{
1510	struct ceph_mds_session *session;
1511	int ret;
1512
1513	session = __ceph_lookup_mds_session(mdsc, target);
1514	if (!session) {
1515		session = register_session(mdsc, target);
1516		if (IS_ERR(session))
1517			return session;
1518	}
1519	if (session->s_state == CEPH_MDS_SESSION_NEW ||
1520	    session->s_state == CEPH_MDS_SESSION_CLOSING) {
1521		ret = __open_session(mdsc, session);
1522		if (ret)
1523			return ERR_PTR(ret);
1524	}
1525
1526	return session;
1527}
1528
1529struct ceph_mds_session *
1530ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1531{
1532	struct ceph_mds_session *session;
1533
1534	dout("open_export_target_session to mds%d\n", target);
1535
1536	mutex_lock(&mdsc->mutex);
1537	session = __open_export_target_session(mdsc, target);
1538	mutex_unlock(&mdsc->mutex);
1539
1540	return session;
1541}
1542
1543static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1544					  struct ceph_mds_session *session)
1545{
1546	struct ceph_mds_info *mi;
1547	struct ceph_mds_session *ts;
1548	int i, mds = session->s_mds;
1549
1550	if (mds >= mdsc->mdsmap->possible_max_rank)
1551		return;
1552
1553	mi = &mdsc->mdsmap->m_info[mds];
1554	dout("open_export_target_sessions for mds%d (%d targets)\n",
1555	     session->s_mds, mi->num_export_targets);
1556
1557	for (i = 0; i < mi->num_export_targets; i++) {
1558		ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1559		ceph_put_mds_session(ts);
1560	}
1561}
1562
1563void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1564					   struct ceph_mds_session *session)
1565{
1566	mutex_lock(&mdsc->mutex);
1567	__open_export_target_sessions(mdsc, session);
1568	mutex_unlock(&mdsc->mutex);
1569}
1570
1571/*
1572 * session caps
1573 */
1574
1575static void detach_cap_releases(struct ceph_mds_session *session,
1576				struct list_head *target)
1577{
1578	lockdep_assert_held(&session->s_cap_lock);
1579
1580	list_splice_init(&session->s_cap_releases, target);
1581	session->s_num_cap_releases = 0;
1582	dout("dispose_cap_releases mds%d\n", session->s_mds);
1583}
1584
1585static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1586				 struct list_head *dispose)
1587{
1588	while (!list_empty(dispose)) {
1589		struct ceph_cap *cap;
1590		/* zero out the in-progress message */
1591		cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1592		list_del(&cap->session_caps);
1593		ceph_put_cap(mdsc, cap);
1594	}
1595}
1596
1597static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1598				     struct ceph_mds_session *session)
1599{
1600	struct ceph_mds_request *req;
1601	struct rb_node *p;
1602
1603	dout("cleanup_session_requests mds%d\n", session->s_mds);
1604	mutex_lock(&mdsc->mutex);
1605	while (!list_empty(&session->s_unsafe)) {
1606		req = list_first_entry(&session->s_unsafe,
1607				       struct ceph_mds_request, r_unsafe_item);
1608		pr_warn_ratelimited(" dropping unsafe request %llu\n",
1609				    req->r_tid);
1610		if (req->r_target_inode)
1611			mapping_set_error(req->r_target_inode->i_mapping, -EIO);
1612		if (req->r_unsafe_dir)
1613			mapping_set_error(req->r_unsafe_dir->i_mapping, -EIO);
1614		__unregister_request(mdsc, req);
1615	}
1616	/* zero r_attempts, so kick_requests() will re-send requests */
1617	p = rb_first(&mdsc->request_tree);
1618	while (p) {
1619		req = rb_entry(p, struct ceph_mds_request, r_node);
1620		p = rb_next(p);
1621		if (req->r_session &&
1622		    req->r_session->s_mds == session->s_mds)
1623			req->r_attempts = 0;
1624	}
1625	mutex_unlock(&mdsc->mutex);
1626}
1627
1628/*
1629 * Helper to safely iterate over all caps associated with a session, with
1630 * special care taken to handle a racing __ceph_remove_cap().
1631 *
1632 * Caller must hold session s_mutex.
1633 */
1634int ceph_iterate_session_caps(struct ceph_mds_session *session,
1635			      int (*cb)(struct inode *, struct ceph_cap *,
1636					void *), void *arg)
1637{
1638	struct list_head *p;
1639	struct ceph_cap *cap;
1640	struct inode *inode, *last_inode = NULL;
1641	struct ceph_cap *old_cap = NULL;
1642	int ret;
1643
1644	dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1645	spin_lock(&session->s_cap_lock);
1646	p = session->s_caps.next;
1647	while (p != &session->s_caps) {
1648		cap = list_entry(p, struct ceph_cap, session_caps);
1649		inode = igrab(&cap->ci->netfs.inode);
1650		if (!inode) {
1651			p = p->next;
1652			continue;
1653		}
1654		session->s_cap_iterator = cap;
1655		spin_unlock(&session->s_cap_lock);
1656
1657		if (last_inode) {
1658			iput(last_inode);
1659			last_inode = NULL;
1660		}
1661		if (old_cap) {
1662			ceph_put_cap(session->s_mdsc, old_cap);
1663			old_cap = NULL;
1664		}
1665
1666		ret = cb(inode, cap, arg);
1667		last_inode = inode;
1668
1669		spin_lock(&session->s_cap_lock);
1670		p = p->next;
1671		if (!cap->ci) {
1672			dout("iterate_session_caps  finishing cap %p removal\n",
1673			     cap);
1674			BUG_ON(cap->session != session);
1675			cap->session = NULL;
1676			list_del_init(&cap->session_caps);
1677			session->s_nr_caps--;
1678			atomic64_dec(&session->s_mdsc->metric.total_caps);
1679			if (cap->queue_release)
1680				__ceph_queue_cap_release(session, cap);
1681			else
1682				old_cap = cap;  /* put_cap it w/o locks held */
1683		}
1684		if (ret < 0)
1685			goto out;
1686	}
1687	ret = 0;
1688out:
1689	session->s_cap_iterator = NULL;
1690	spin_unlock(&session->s_cap_lock);
1691
1692	iput(last_inode);
1693	if (old_cap)
1694		ceph_put_cap(session->s_mdsc, old_cap);
1695
1696	return ret;
1697}
1698
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1699static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1700				  void *arg)
1701{
 
 
1702	struct ceph_inode_info *ci = ceph_inode(inode);
 
 
1703	bool invalidate = false;
1704	int iputs;
1705
1706	dout("removing cap %p, ci is %p, inode is %p\n",
1707	     cap, ci, &ci->netfs.inode);
1708	spin_lock(&ci->i_ceph_lock);
1709	iputs = ceph_purge_inode_cap(inode, cap, &invalidate);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1710	spin_unlock(&ci->i_ceph_lock);
 
 
 
 
 
 
 
 
1711
1712	wake_up_all(&ci->i_cap_wq);
1713	if (invalidate)
1714		ceph_queue_invalidate(inode);
1715	while (iputs--)
 
 
1716		iput(inode);
1717	return 0;
1718}
1719
1720/*
1721 * caller must hold session s_mutex
1722 */
1723static void remove_session_caps(struct ceph_mds_session *session)
1724{
1725	struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1726	struct super_block *sb = fsc->sb;
1727	LIST_HEAD(dispose);
1728
1729	dout("remove_session_caps on %p\n", session);
1730	ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1731
1732	wake_up_all(&fsc->mdsc->cap_flushing_wq);
1733
1734	spin_lock(&session->s_cap_lock);
1735	if (session->s_nr_caps > 0) {
1736		struct inode *inode;
1737		struct ceph_cap *cap, *prev = NULL;
1738		struct ceph_vino vino;
1739		/*
1740		 * iterate_session_caps() skips inodes that are being
1741		 * deleted, we need to wait until deletions are complete.
1742		 * __wait_on_freeing_inode() is designed for the job,
1743		 * but it is not exported, so use lookup inode function
1744		 * to access it.
1745		 */
1746		while (!list_empty(&session->s_caps)) {
1747			cap = list_entry(session->s_caps.next,
1748					 struct ceph_cap, session_caps);
1749			if (cap == prev)
1750				break;
1751			prev = cap;
1752			vino = cap->ci->i_vino;
1753			spin_unlock(&session->s_cap_lock);
1754
1755			inode = ceph_find_inode(sb, vino);
1756			iput(inode);
1757
1758			spin_lock(&session->s_cap_lock);
1759		}
1760	}
1761
1762	// drop cap expires and unlock s_cap_lock
1763	detach_cap_releases(session, &dispose);
1764
1765	BUG_ON(session->s_nr_caps > 0);
1766	BUG_ON(!list_empty(&session->s_cap_flushing));
1767	spin_unlock(&session->s_cap_lock);
1768	dispose_cap_releases(session->s_mdsc, &dispose);
1769}
1770
1771enum {
1772	RECONNECT,
1773	RENEWCAPS,
1774	FORCE_RO,
1775};
1776
1777/*
1778 * wake up any threads waiting on this session's caps.  if the cap is
1779 * old (didn't get renewed on the client reconnect), remove it now.
1780 *
1781 * caller must hold s_mutex.
1782 */
1783static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1784			      void *arg)
1785{
1786	struct ceph_inode_info *ci = ceph_inode(inode);
1787	unsigned long ev = (unsigned long)arg;
1788
1789	if (ev == RECONNECT) {
1790		spin_lock(&ci->i_ceph_lock);
1791		ci->i_wanted_max_size = 0;
1792		ci->i_requested_max_size = 0;
1793		spin_unlock(&ci->i_ceph_lock);
1794	} else if (ev == RENEWCAPS) {
1795		if (cap->cap_gen < atomic_read(&cap->session->s_cap_gen)) {
1796			/* mds did not re-issue stale cap */
1797			spin_lock(&ci->i_ceph_lock);
1798			cap->issued = cap->implemented = CEPH_CAP_PIN;
1799			spin_unlock(&ci->i_ceph_lock);
1800		}
1801	} else if (ev == FORCE_RO) {
1802	}
1803	wake_up_all(&ci->i_cap_wq);
1804	return 0;
1805}
1806
1807static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1808{
1809	dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1810	ceph_iterate_session_caps(session, wake_up_session_cb,
1811				  (void *)(unsigned long)ev);
1812}
1813
1814/*
1815 * Send periodic message to MDS renewing all currently held caps.  The
1816 * ack will reset the expiration for all caps from this session.
1817 *
1818 * caller holds s_mutex
1819 */
1820static int send_renew_caps(struct ceph_mds_client *mdsc,
1821			   struct ceph_mds_session *session)
1822{
1823	struct ceph_msg *msg;
1824	int state;
1825
1826	if (time_after_eq(jiffies, session->s_cap_ttl) &&
1827	    time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1828		pr_info("mds%d caps stale\n", session->s_mds);
1829	session->s_renew_requested = jiffies;
1830
1831	/* do not try to renew caps until a recovering mds has reconnected
1832	 * with its clients. */
1833	state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1834	if (state < CEPH_MDS_STATE_RECONNECT) {
1835		dout("send_renew_caps ignoring mds%d (%s)\n",
1836		     session->s_mds, ceph_mds_state_name(state));
1837		return 0;
1838	}
1839
1840	dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1841		ceph_mds_state_name(state));
1842	msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1843				      ++session->s_renew_seq);
1844	if (!msg)
1845		return -ENOMEM;
1846	ceph_con_send(&session->s_con, msg);
1847	return 0;
1848}
1849
1850static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1851			     struct ceph_mds_session *session, u64 seq)
1852{
1853	struct ceph_msg *msg;
1854
1855	dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1856	     session->s_mds, ceph_session_state_name(session->s_state), seq);
1857	msg = ceph_create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1858	if (!msg)
1859		return -ENOMEM;
1860	ceph_con_send(&session->s_con, msg);
1861	return 0;
1862}
1863
1864
1865/*
1866 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1867 *
1868 * Called under session->s_mutex
1869 */
1870static void renewed_caps(struct ceph_mds_client *mdsc,
1871			 struct ceph_mds_session *session, int is_renew)
1872{
1873	int was_stale;
1874	int wake = 0;
1875
1876	spin_lock(&session->s_cap_lock);
1877	was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1878
1879	session->s_cap_ttl = session->s_renew_requested +
1880		mdsc->mdsmap->m_session_timeout*HZ;
1881
1882	if (was_stale) {
1883		if (time_before(jiffies, session->s_cap_ttl)) {
1884			pr_info("mds%d caps renewed\n", session->s_mds);
1885			wake = 1;
1886		} else {
1887			pr_info("mds%d caps still stale\n", session->s_mds);
1888		}
1889	}
1890	dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1891	     session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1892	     time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1893	spin_unlock(&session->s_cap_lock);
1894
1895	if (wake)
1896		wake_up_session_caps(session, RENEWCAPS);
1897}
1898
1899/*
1900 * send a session close request
1901 */
1902static int request_close_session(struct ceph_mds_session *session)
1903{
1904	struct ceph_msg *msg;
1905
1906	dout("request_close_session mds%d state %s seq %lld\n",
1907	     session->s_mds, ceph_session_state_name(session->s_state),
1908	     session->s_seq);
1909	msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_CLOSE,
1910				      session->s_seq);
1911	if (!msg)
1912		return -ENOMEM;
1913	ceph_con_send(&session->s_con, msg);
1914	return 1;
1915}
1916
1917/*
1918 * Called with s_mutex held.
1919 */
1920static int __close_session(struct ceph_mds_client *mdsc,
1921			 struct ceph_mds_session *session)
1922{
1923	if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1924		return 0;
1925	session->s_state = CEPH_MDS_SESSION_CLOSING;
1926	return request_close_session(session);
1927}
1928
1929static bool drop_negative_children(struct dentry *dentry)
1930{
1931	struct dentry *child;
1932	bool all_negative = true;
1933
1934	if (!d_is_dir(dentry))
1935		goto out;
1936
1937	spin_lock(&dentry->d_lock);
1938	list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1939		if (d_really_is_positive(child)) {
1940			all_negative = false;
1941			break;
1942		}
1943	}
1944	spin_unlock(&dentry->d_lock);
1945
1946	if (all_negative)
1947		shrink_dcache_parent(dentry);
1948out:
1949	return all_negative;
1950}
1951
1952/*
1953 * Trim old(er) caps.
1954 *
1955 * Because we can't cache an inode without one or more caps, we do
1956 * this indirectly: if a cap is unused, we prune its aliases, at which
1957 * point the inode will hopefully get dropped to.
1958 *
1959 * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1960 * memory pressure from the MDS, though, so it needn't be perfect.
1961 */
1962static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1963{
1964	int *remaining = arg;
1965	struct ceph_inode_info *ci = ceph_inode(inode);
1966	int used, wanted, oissued, mine;
1967
1968	if (*remaining <= 0)
1969		return -1;
1970
1971	spin_lock(&ci->i_ceph_lock);
1972	mine = cap->issued | cap->implemented;
1973	used = __ceph_caps_used(ci);
1974	wanted = __ceph_caps_file_wanted(ci);
1975	oissued = __ceph_caps_issued_other(ci, cap);
1976
1977	dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1978	     inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1979	     ceph_cap_string(used), ceph_cap_string(wanted));
1980	if (cap == ci->i_auth_cap) {
1981		if (ci->i_dirty_caps || ci->i_flushing_caps ||
1982		    !list_empty(&ci->i_cap_snaps))
1983			goto out;
1984		if ((used | wanted) & CEPH_CAP_ANY_WR)
1985			goto out;
1986		/* Note: it's possible that i_filelock_ref becomes non-zero
1987		 * after dropping auth caps. It doesn't hurt because reply
1988		 * of lock mds request will re-add auth caps. */
1989		if (atomic_read(&ci->i_filelock_ref) > 0)
1990			goto out;
1991	}
1992	/* The inode has cached pages, but it's no longer used.
1993	 * we can safely drop it */
1994	if (S_ISREG(inode->i_mode) &&
1995	    wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1996	    !(oissued & CEPH_CAP_FILE_CACHE)) {
1997	  used = 0;
1998	  oissued = 0;
1999	}
2000	if ((used | wanted) & ~oissued & mine)
2001		goto out;   /* we need these caps */
2002
2003	if (oissued) {
2004		/* we aren't the only cap.. just remove us */
2005		ceph_remove_cap(cap, true);
2006		(*remaining)--;
2007	} else {
2008		struct dentry *dentry;
2009		/* try dropping referring dentries */
2010		spin_unlock(&ci->i_ceph_lock);
2011		dentry = d_find_any_alias(inode);
2012		if (dentry && drop_negative_children(dentry)) {
2013			int count;
2014			dput(dentry);
2015			d_prune_aliases(inode);
2016			count = atomic_read(&inode->i_count);
2017			if (count == 1)
2018				(*remaining)--;
2019			dout("trim_caps_cb %p cap %p pruned, count now %d\n",
2020			     inode, cap, count);
2021		} else {
2022			dput(dentry);
2023		}
2024		return 0;
2025	}
2026
2027out:
2028	spin_unlock(&ci->i_ceph_lock);
2029	return 0;
2030}
2031
2032/*
2033 * Trim session cap count down to some max number.
2034 */
2035int ceph_trim_caps(struct ceph_mds_client *mdsc,
2036		   struct ceph_mds_session *session,
2037		   int max_caps)
2038{
2039	int trim_caps = session->s_nr_caps - max_caps;
2040
2041	dout("trim_caps mds%d start: %d / %d, trim %d\n",
2042	     session->s_mds, session->s_nr_caps, max_caps, trim_caps);
2043	if (trim_caps > 0) {
2044		int remaining = trim_caps;
2045
2046		ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
2047		dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
2048		     session->s_mds, session->s_nr_caps, max_caps,
2049			trim_caps - remaining);
2050	}
2051
2052	ceph_flush_cap_releases(mdsc, session);
2053	return 0;
2054}
2055
2056static int check_caps_flush(struct ceph_mds_client *mdsc,
2057			    u64 want_flush_tid)
2058{
2059	int ret = 1;
2060
2061	spin_lock(&mdsc->cap_dirty_lock);
2062	if (!list_empty(&mdsc->cap_flush_list)) {
2063		struct ceph_cap_flush *cf =
2064			list_first_entry(&mdsc->cap_flush_list,
2065					 struct ceph_cap_flush, g_list);
2066		if (cf->tid <= want_flush_tid) {
2067			dout("check_caps_flush still flushing tid "
2068			     "%llu <= %llu\n", cf->tid, want_flush_tid);
2069			ret = 0;
2070		}
2071	}
2072	spin_unlock(&mdsc->cap_dirty_lock);
2073	return ret;
2074}
2075
2076/*
2077 * flush all dirty inode data to disk.
2078 *
2079 * returns true if we've flushed through want_flush_tid
2080 */
2081static void wait_caps_flush(struct ceph_mds_client *mdsc,
2082			    u64 want_flush_tid)
2083{
2084	dout("check_caps_flush want %llu\n", want_flush_tid);
2085
2086	wait_event(mdsc->cap_flushing_wq,
2087		   check_caps_flush(mdsc, want_flush_tid));
2088
2089	dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
2090}
2091
2092/*
2093 * called under s_mutex
2094 */
2095static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
2096				   struct ceph_mds_session *session)
2097{
2098	struct ceph_msg *msg = NULL;
2099	struct ceph_mds_cap_release *head;
2100	struct ceph_mds_cap_item *item;
2101	struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
2102	struct ceph_cap *cap;
2103	LIST_HEAD(tmp_list);
2104	int num_cap_releases;
2105	__le32	barrier, *cap_barrier;
2106
2107	down_read(&osdc->lock);
2108	barrier = cpu_to_le32(osdc->epoch_barrier);
2109	up_read(&osdc->lock);
2110
2111	spin_lock(&session->s_cap_lock);
2112again:
2113	list_splice_init(&session->s_cap_releases, &tmp_list);
2114	num_cap_releases = session->s_num_cap_releases;
2115	session->s_num_cap_releases = 0;
2116	spin_unlock(&session->s_cap_lock);
2117
2118	while (!list_empty(&tmp_list)) {
2119		if (!msg) {
2120			msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
2121					PAGE_SIZE, GFP_NOFS, false);
2122			if (!msg)
2123				goto out_err;
2124			head = msg->front.iov_base;
2125			head->num = cpu_to_le32(0);
2126			msg->front.iov_len = sizeof(*head);
2127
2128			msg->hdr.version = cpu_to_le16(2);
2129			msg->hdr.compat_version = cpu_to_le16(1);
2130		}
2131
2132		cap = list_first_entry(&tmp_list, struct ceph_cap,
2133					session_caps);
2134		list_del(&cap->session_caps);
2135		num_cap_releases--;
2136
2137		head = msg->front.iov_base;
2138		put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
2139				   &head->num);
2140		item = msg->front.iov_base + msg->front.iov_len;
2141		item->ino = cpu_to_le64(cap->cap_ino);
2142		item->cap_id = cpu_to_le64(cap->cap_id);
2143		item->migrate_seq = cpu_to_le32(cap->mseq);
2144		item->seq = cpu_to_le32(cap->issue_seq);
2145		msg->front.iov_len += sizeof(*item);
2146
2147		ceph_put_cap(mdsc, cap);
2148
2149		if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
2150			// Append cap_barrier field
2151			cap_barrier = msg->front.iov_base + msg->front.iov_len;
2152			*cap_barrier = barrier;
2153			msg->front.iov_len += sizeof(*cap_barrier);
2154
2155			msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2156			dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2157			ceph_con_send(&session->s_con, msg);
2158			msg = NULL;
2159		}
2160	}
2161
2162	BUG_ON(num_cap_releases != 0);
2163
2164	spin_lock(&session->s_cap_lock);
2165	if (!list_empty(&session->s_cap_releases))
2166		goto again;
2167	spin_unlock(&session->s_cap_lock);
2168
2169	if (msg) {
2170		// Append cap_barrier field
2171		cap_barrier = msg->front.iov_base + msg->front.iov_len;
2172		*cap_barrier = barrier;
2173		msg->front.iov_len += sizeof(*cap_barrier);
2174
2175		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2176		dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2177		ceph_con_send(&session->s_con, msg);
2178	}
2179	return;
2180out_err:
2181	pr_err("send_cap_releases mds%d, failed to allocate message\n",
2182		session->s_mds);
2183	spin_lock(&session->s_cap_lock);
2184	list_splice(&tmp_list, &session->s_cap_releases);
2185	session->s_num_cap_releases += num_cap_releases;
2186	spin_unlock(&session->s_cap_lock);
2187}
2188
2189static void ceph_cap_release_work(struct work_struct *work)
2190{
2191	struct ceph_mds_session *session =
2192		container_of(work, struct ceph_mds_session, s_cap_release_work);
2193
2194	mutex_lock(&session->s_mutex);
2195	if (session->s_state == CEPH_MDS_SESSION_OPEN ||
2196	    session->s_state == CEPH_MDS_SESSION_HUNG)
2197		ceph_send_cap_releases(session->s_mdsc, session);
2198	mutex_unlock(&session->s_mutex);
2199	ceph_put_mds_session(session);
2200}
2201
2202void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
2203		             struct ceph_mds_session *session)
2204{
2205	if (mdsc->stopping)
2206		return;
2207
2208	ceph_get_mds_session(session);
2209	if (queue_work(mdsc->fsc->cap_wq,
2210		       &session->s_cap_release_work)) {
2211		dout("cap release work queued\n");
2212	} else {
2213		ceph_put_mds_session(session);
2214		dout("failed to queue cap release work\n");
2215	}
2216}
2217
2218/*
2219 * caller holds session->s_cap_lock
2220 */
2221void __ceph_queue_cap_release(struct ceph_mds_session *session,
2222			      struct ceph_cap *cap)
2223{
2224	list_add_tail(&cap->session_caps, &session->s_cap_releases);
2225	session->s_num_cap_releases++;
2226
2227	if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
2228		ceph_flush_cap_releases(session->s_mdsc, session);
2229}
2230
2231static void ceph_cap_reclaim_work(struct work_struct *work)
2232{
2233	struct ceph_mds_client *mdsc =
2234		container_of(work, struct ceph_mds_client, cap_reclaim_work);
2235	int ret = ceph_trim_dentries(mdsc);
2236	if (ret == -EAGAIN)
2237		ceph_queue_cap_reclaim_work(mdsc);
2238}
2239
2240void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2241{
2242	if (mdsc->stopping)
2243		return;
2244
2245        if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2246                dout("caps reclaim work queued\n");
2247        } else {
2248                dout("failed to queue caps release work\n");
2249        }
2250}
2251
2252void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2253{
2254	int val;
2255	if (!nr)
2256		return;
2257	val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2258	if ((val % CEPH_CAPS_PER_RELEASE) < nr) {
2259		atomic_set(&mdsc->cap_reclaim_pending, 0);
2260		ceph_queue_cap_reclaim_work(mdsc);
2261	}
2262}
2263
2264/*
2265 * requests
2266 */
2267
2268int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2269				    struct inode *dir)
2270{
2271	struct ceph_inode_info *ci = ceph_inode(dir);
2272	struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2273	struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2274	size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2275	unsigned int num_entries;
2276	int order;
2277
2278	spin_lock(&ci->i_ceph_lock);
2279	num_entries = ci->i_files + ci->i_subdirs;
2280	spin_unlock(&ci->i_ceph_lock);
2281	num_entries = max(num_entries, 1U);
2282	num_entries = min(num_entries, opt->max_readdir);
2283
2284	order = get_order(size * num_entries);
2285	while (order >= 0) {
2286		rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2287							     __GFP_NOWARN |
2288							     __GFP_ZERO,
2289							     order);
2290		if (rinfo->dir_entries)
2291			break;
2292		order--;
2293	}
2294	if (!rinfo->dir_entries)
2295		return -ENOMEM;
2296
2297	num_entries = (PAGE_SIZE << order) / size;
2298	num_entries = min(num_entries, opt->max_readdir);
2299
2300	rinfo->dir_buf_size = PAGE_SIZE << order;
2301	req->r_num_caps = num_entries + 1;
2302	req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2303	req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2304	return 0;
2305}
2306
2307/*
2308 * Create an mds request.
2309 */
2310struct ceph_mds_request *
2311ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2312{
2313	struct ceph_mds_request *req;
2314
2315	req = kmem_cache_zalloc(ceph_mds_request_cachep, GFP_NOFS);
2316	if (!req)
2317		return ERR_PTR(-ENOMEM);
2318
2319	mutex_init(&req->r_fill_mutex);
2320	req->r_mdsc = mdsc;
2321	req->r_started = jiffies;
2322	req->r_start_latency = ktime_get();
2323	req->r_resend_mds = -1;
2324	INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2325	INIT_LIST_HEAD(&req->r_unsafe_target_item);
2326	req->r_fmode = -1;
2327	req->r_feature_needed = -1;
2328	kref_init(&req->r_kref);
2329	RB_CLEAR_NODE(&req->r_node);
2330	INIT_LIST_HEAD(&req->r_wait);
2331	init_completion(&req->r_completion);
2332	init_completion(&req->r_safe_completion);
2333	INIT_LIST_HEAD(&req->r_unsafe_item);
2334
2335	ktime_get_coarse_real_ts64(&req->r_stamp);
2336
2337	req->r_op = op;
2338	req->r_direct_mode = mode;
2339	return req;
2340}
2341
2342/*
2343 * return oldest (lowest) request, tid in request tree, 0 if none.
2344 *
2345 * called under mdsc->mutex.
2346 */
2347static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2348{
2349	if (RB_EMPTY_ROOT(&mdsc->request_tree))
2350		return NULL;
2351	return rb_entry(rb_first(&mdsc->request_tree),
2352			struct ceph_mds_request, r_node);
2353}
2354
2355static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2356{
2357	return mdsc->oldest_tid;
2358}
2359
2360/*
2361 * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2362 * on build_path_from_dentry in fs/cifs/dir.c.
2363 *
2364 * If @stop_on_nosnap, generate path relative to the first non-snapped
2365 * inode.
2366 *
2367 * Encode hidden .snap dirs as a double /, i.e.
2368 *   foo/.snap/bar -> foo//bar
2369 */
2370char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2371			   int stop_on_nosnap)
2372{
2373	struct dentry *temp;
2374	char *path;
2375	int pos;
2376	unsigned seq;
2377	u64 base;
2378
2379	if (!dentry)
2380		return ERR_PTR(-EINVAL);
2381
2382	path = __getname();
2383	if (!path)
2384		return ERR_PTR(-ENOMEM);
2385retry:
2386	pos = PATH_MAX - 1;
2387	path[pos] = '\0';
2388
2389	seq = read_seqbegin(&rename_lock);
2390	rcu_read_lock();
2391	temp = dentry;
2392	for (;;) {
2393		struct inode *inode;
2394
2395		spin_lock(&temp->d_lock);
2396		inode = d_inode(temp);
2397		if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2398			dout("build_path path+%d: %p SNAPDIR\n",
2399			     pos, temp);
2400		} else if (stop_on_nosnap && inode && dentry != temp &&
2401			   ceph_snap(inode) == CEPH_NOSNAP) {
2402			spin_unlock(&temp->d_lock);
2403			pos++; /* get rid of any prepended '/' */
2404			break;
2405		} else {
2406			pos -= temp->d_name.len;
2407			if (pos < 0) {
2408				spin_unlock(&temp->d_lock);
2409				break;
2410			}
2411			memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2412		}
2413		spin_unlock(&temp->d_lock);
2414		temp = READ_ONCE(temp->d_parent);
2415
2416		/* Are we at the root? */
2417		if (IS_ROOT(temp))
2418			break;
2419
2420		/* Are we out of buffer? */
2421		if (--pos < 0)
2422			break;
2423
2424		path[pos] = '/';
2425	}
2426	base = ceph_ino(d_inode(temp));
2427	rcu_read_unlock();
2428
2429	if (read_seqretry(&rename_lock, seq))
2430		goto retry;
2431
2432	if (pos < 0) {
2433		/*
2434		 * A rename didn't occur, but somehow we didn't end up where
2435		 * we thought we would. Throw a warning and try again.
2436		 */
2437		pr_warn("build_path did not end path lookup where "
2438			"expected, pos is %d\n", pos);
2439		goto retry;
2440	}
2441
2442	*pbase = base;
2443	*plen = PATH_MAX - 1 - pos;
2444	dout("build_path on %p %d built %llx '%.*s'\n",
2445	     dentry, d_count(dentry), base, *plen, path + pos);
2446	return path + pos;
2447}
2448
2449static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2450			     const char **ppath, int *ppathlen, u64 *pino,
2451			     bool *pfreepath, bool parent_locked)
2452{
2453	char *path;
2454
2455	rcu_read_lock();
2456	if (!dir)
2457		dir = d_inode_rcu(dentry->d_parent);
2458	if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2459		*pino = ceph_ino(dir);
2460		rcu_read_unlock();
2461		*ppath = dentry->d_name.name;
2462		*ppathlen = dentry->d_name.len;
2463		return 0;
2464	}
2465	rcu_read_unlock();
2466	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2467	if (IS_ERR(path))
2468		return PTR_ERR(path);
2469	*ppath = path;
2470	*pfreepath = true;
2471	return 0;
2472}
2473
2474static int build_inode_path(struct inode *inode,
2475			    const char **ppath, int *ppathlen, u64 *pino,
2476			    bool *pfreepath)
2477{
2478	struct dentry *dentry;
2479	char *path;
2480
2481	if (ceph_snap(inode) == CEPH_NOSNAP) {
2482		*pino = ceph_ino(inode);
2483		*ppathlen = 0;
2484		return 0;
2485	}
2486	dentry = d_find_alias(inode);
2487	path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2488	dput(dentry);
2489	if (IS_ERR(path))
2490		return PTR_ERR(path);
2491	*ppath = path;
2492	*pfreepath = true;
2493	return 0;
2494}
2495
2496/*
2497 * request arguments may be specified via an inode *, a dentry *, or
2498 * an explicit ino+path.
2499 */
2500static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2501				  struct inode *rdiri, const char *rpath,
2502				  u64 rino, const char **ppath, int *pathlen,
2503				  u64 *ino, bool *freepath, bool parent_locked)
2504{
2505	int r = 0;
2506
2507	if (rinode) {
2508		r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2509		dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2510		     ceph_snap(rinode));
2511	} else if (rdentry) {
2512		r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2513					freepath, parent_locked);
2514		dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2515		     *ppath);
2516	} else if (rpath || rino) {
2517		*ino = rino;
2518		*ppath = rpath;
2519		*pathlen = rpath ? strlen(rpath) : 0;
2520		dout(" path %.*s\n", *pathlen, rpath);
2521	}
2522
2523	return r;
2524}
2525
2526static void encode_timestamp_and_gids(void **p,
2527				      const struct ceph_mds_request *req)
2528{
2529	struct ceph_timespec ts;
2530	int i;
2531
2532	ceph_encode_timespec64(&ts, &req->r_stamp);
2533	ceph_encode_copy(p, &ts, sizeof(ts));
2534
2535	/* gid_list */
2536	ceph_encode_32(p, req->r_cred->group_info->ngroups);
2537	for (i = 0; i < req->r_cred->group_info->ngroups; i++)
2538		ceph_encode_64(p, from_kgid(&init_user_ns,
2539					    req->r_cred->group_info->gid[i]));
2540}
2541
2542/*
2543 * called under mdsc->mutex
2544 */
2545static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
2546					       struct ceph_mds_request *req,
2547					       bool drop_cap_releases)
2548{
2549	int mds = session->s_mds;
2550	struct ceph_mds_client *mdsc = session->s_mdsc;
2551	struct ceph_msg *msg;
2552	struct ceph_mds_request_head_old *head;
2553	const char *path1 = NULL;
2554	const char *path2 = NULL;
2555	u64 ino1 = 0, ino2 = 0;
2556	int pathlen1 = 0, pathlen2 = 0;
2557	bool freepath1 = false, freepath2 = false;
2558	int len;
2559	u16 releases;
2560	void *p, *end;
2561	int ret;
2562	bool legacy = !(session->s_con.peer_features & CEPH_FEATURE_FS_BTIME);
2563
2564	ret = set_request_path_attr(req->r_inode, req->r_dentry,
2565			      req->r_parent, req->r_path1, req->r_ino1.ino,
2566			      &path1, &pathlen1, &ino1, &freepath1,
2567			      test_bit(CEPH_MDS_R_PARENT_LOCKED,
2568					&req->r_req_flags));
2569	if (ret < 0) {
2570		msg = ERR_PTR(ret);
2571		goto out;
2572	}
2573
2574	/* If r_old_dentry is set, then assume that its parent is locked */
2575	ret = set_request_path_attr(NULL, req->r_old_dentry,
2576			      req->r_old_dentry_dir,
2577			      req->r_path2, req->r_ino2.ino,
2578			      &path2, &pathlen2, &ino2, &freepath2, true);
2579	if (ret < 0) {
2580		msg = ERR_PTR(ret);
2581		goto out_free1;
2582	}
2583
2584	len = legacy ? sizeof(*head) : sizeof(struct ceph_mds_request_head);
2585	len += pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2586		sizeof(struct ceph_timespec);
2587	len += sizeof(u32) + (sizeof(u64) * req->r_cred->group_info->ngroups);
2588
2589	/* calculate (max) length for cap releases */
2590	len += sizeof(struct ceph_mds_request_release) *
2591		(!!req->r_inode_drop + !!req->r_dentry_drop +
2592		 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2593
2594	if (req->r_dentry_drop)
2595		len += pathlen1;
2596	if (req->r_old_dentry_drop)
2597		len += pathlen2;
2598
2599	msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2600	if (!msg) {
2601		msg = ERR_PTR(-ENOMEM);
2602		goto out_free2;
2603	}
2604
2605	msg->hdr.tid = cpu_to_le64(req->r_tid);
2606
2607	/*
2608	 * The old ceph_mds_request_head didn't contain a version field, and
2609	 * one was added when we moved the message version from 3->4.
2610	 */
2611	if (legacy) {
2612		msg->hdr.version = cpu_to_le16(3);
2613		head = msg->front.iov_base;
2614		p = msg->front.iov_base + sizeof(*head);
2615	} else {
2616		struct ceph_mds_request_head *new_head = msg->front.iov_base;
2617
2618		msg->hdr.version = cpu_to_le16(4);
2619		new_head->version = cpu_to_le16(CEPH_MDS_REQUEST_HEAD_VERSION);
2620		head = (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2621		p = msg->front.iov_base + sizeof(*new_head);
2622	}
2623
2624	end = msg->front.iov_base + msg->front.iov_len;
2625
2626	head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2627	head->op = cpu_to_le32(req->r_op);
2628	head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns,
2629						 req->r_cred->fsuid));
2630	head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns,
2631						 req->r_cred->fsgid));
2632	head->ino = cpu_to_le64(req->r_deleg_ino);
2633	head->args = req->r_args;
2634
2635	ceph_encode_filepath(&p, end, ino1, path1);
2636	ceph_encode_filepath(&p, end, ino2, path2);
2637
2638	/* make note of release offset, in case we need to replay */
2639	req->r_request_release_offset = p - msg->front.iov_base;
2640
2641	/* cap releases */
2642	releases = 0;
2643	if (req->r_inode_drop)
2644		releases += ceph_encode_inode_release(&p,
2645		      req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2646		      mds, req->r_inode_drop, req->r_inode_unless,
2647		      req->r_op == CEPH_MDS_OP_READDIR);
2648	if (req->r_dentry_drop)
2649		releases += ceph_encode_dentry_release(&p, req->r_dentry,
2650				req->r_parent, mds, req->r_dentry_drop,
2651				req->r_dentry_unless);
2652	if (req->r_old_dentry_drop)
2653		releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2654				req->r_old_dentry_dir, mds,
2655				req->r_old_dentry_drop,
2656				req->r_old_dentry_unless);
2657	if (req->r_old_inode_drop)
2658		releases += ceph_encode_inode_release(&p,
2659		      d_inode(req->r_old_dentry),
2660		      mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2661
2662	if (drop_cap_releases) {
2663		releases = 0;
2664		p = msg->front.iov_base + req->r_request_release_offset;
2665	}
2666
2667	head->num_releases = cpu_to_le16(releases);
2668
2669	encode_timestamp_and_gids(&p, req);
2670
2671	if (WARN_ON_ONCE(p > end)) {
2672		ceph_msg_put(msg);
2673		msg = ERR_PTR(-ERANGE);
2674		goto out_free2;
2675	}
2676
2677	msg->front.iov_len = p - msg->front.iov_base;
2678	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2679
2680	if (req->r_pagelist) {
2681		struct ceph_pagelist *pagelist = req->r_pagelist;
2682		ceph_msg_data_add_pagelist(msg, pagelist);
2683		msg->hdr.data_len = cpu_to_le32(pagelist->length);
2684	} else {
2685		msg->hdr.data_len = 0;
2686	}
2687
2688	msg->hdr.data_off = cpu_to_le16(0);
2689
2690out_free2:
2691	if (freepath2)
2692		ceph_mdsc_free_path((char *)path2, pathlen2);
2693out_free1:
2694	if (freepath1)
2695		ceph_mdsc_free_path((char *)path1, pathlen1);
2696out:
2697	return msg;
2698}
2699
2700/*
2701 * called under mdsc->mutex if error, under no mutex if
2702 * success.
2703 */
2704static void complete_request(struct ceph_mds_client *mdsc,
2705			     struct ceph_mds_request *req)
2706{
2707	req->r_end_latency = ktime_get();
2708
2709	if (req->r_callback)
2710		req->r_callback(mdsc, req);
2711	complete_all(&req->r_completion);
2712}
2713
2714static struct ceph_mds_request_head_old *
2715find_old_request_head(void *p, u64 features)
2716{
2717	bool legacy = !(features & CEPH_FEATURE_FS_BTIME);
2718	struct ceph_mds_request_head *new_head;
2719
2720	if (legacy)
2721		return (struct ceph_mds_request_head_old *)p;
2722	new_head = (struct ceph_mds_request_head *)p;
2723	return (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2724}
2725
2726/*
2727 * called under mdsc->mutex
2728 */
2729static int __prepare_send_request(struct ceph_mds_session *session,
2730				  struct ceph_mds_request *req,
2731				  bool drop_cap_releases)
2732{
2733	int mds = session->s_mds;
2734	struct ceph_mds_client *mdsc = session->s_mdsc;
2735	struct ceph_mds_request_head_old *rhead;
2736	struct ceph_msg *msg;
2737	int flags = 0, max_retry;
2738
2739	/*
2740	 * The type of 'r_attempts' in kernel 'ceph_mds_request'
2741	 * is 'int', while in 'ceph_mds_request_head' the type of
2742	 * 'num_retry' is '__u8'. So in case the request retries
2743	 *  exceeding 256 times, the MDS will receive a incorrect
2744	 *  retry seq.
2745	 *
2746	 * In this case it's ususally a bug in MDS and continue
2747	 * retrying the request makes no sense.
2748	 *
2749	 * In future this could be fixed in ceph code, so avoid
2750	 * using the hardcode here.
2751	 */
2752	max_retry = sizeof_field(struct ceph_mds_request_head, num_retry);
2753	max_retry = 1 << (max_retry * BITS_PER_BYTE);
2754	if (req->r_attempts >= max_retry) {
2755		pr_warn_ratelimited("%s request tid %llu seq overflow\n",
2756				    __func__, req->r_tid);
2757		return -EMULTIHOP;
2758	}
2759
2760	req->r_attempts++;
2761	if (req->r_inode) {
2762		struct ceph_cap *cap =
2763			ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2764
2765		if (cap)
2766			req->r_sent_on_mseq = cap->mseq;
2767		else
2768			req->r_sent_on_mseq = -1;
2769	}
2770	dout("%s %p tid %lld %s (attempt %d)\n", __func__, req,
2771	     req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2772
2773	if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2774		void *p;
2775
2776		/*
2777		 * Replay.  Do not regenerate message (and rebuild
2778		 * paths, etc.); just use the original message.
2779		 * Rebuilding paths will break for renames because
2780		 * d_move mangles the src name.
2781		 */
2782		msg = req->r_request;
2783		rhead = find_old_request_head(msg->front.iov_base,
2784					      session->s_con.peer_features);
2785
2786		flags = le32_to_cpu(rhead->flags);
2787		flags |= CEPH_MDS_FLAG_REPLAY;
2788		rhead->flags = cpu_to_le32(flags);
2789
2790		if (req->r_target_inode)
2791			rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2792
2793		rhead->num_retry = req->r_attempts - 1;
2794
2795		/* remove cap/dentry releases from message */
2796		rhead->num_releases = 0;
2797
2798		p = msg->front.iov_base + req->r_request_release_offset;
2799		encode_timestamp_and_gids(&p, req);
2800
2801		msg->front.iov_len = p - msg->front.iov_base;
2802		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2803		return 0;
2804	}
2805
2806	if (req->r_request) {
2807		ceph_msg_put(req->r_request);
2808		req->r_request = NULL;
2809	}
2810	msg = create_request_message(session, req, drop_cap_releases);
2811	if (IS_ERR(msg)) {
2812		req->r_err = PTR_ERR(msg);
2813		return PTR_ERR(msg);
2814	}
2815	req->r_request = msg;
2816
2817	rhead = find_old_request_head(msg->front.iov_base,
2818				      session->s_con.peer_features);
2819	rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2820	if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2821		flags |= CEPH_MDS_FLAG_REPLAY;
2822	if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags))
2823		flags |= CEPH_MDS_FLAG_ASYNC;
2824	if (req->r_parent)
2825		flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2826	rhead->flags = cpu_to_le32(flags);
2827	rhead->num_fwd = req->r_num_fwd;
2828	rhead->num_retry = req->r_attempts - 1;
2829
2830	dout(" r_parent = %p\n", req->r_parent);
2831	return 0;
2832}
2833
2834/*
2835 * called under mdsc->mutex
2836 */
2837static int __send_request(struct ceph_mds_session *session,
2838			  struct ceph_mds_request *req,
2839			  bool drop_cap_releases)
2840{
2841	int err;
2842
2843	err = __prepare_send_request(session, req, drop_cap_releases);
2844	if (!err) {
2845		ceph_msg_get(req->r_request);
2846		ceph_con_send(&session->s_con, req->r_request);
2847	}
2848
2849	return err;
2850}
2851
2852/*
2853 * send request, or put it on the appropriate wait list.
2854 */
2855static void __do_request(struct ceph_mds_client *mdsc,
2856			struct ceph_mds_request *req)
2857{
2858	struct ceph_mds_session *session = NULL;
2859	int mds = -1;
2860	int err = 0;
2861	bool random;
2862
2863	if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2864		if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2865			__unregister_request(mdsc, req);
2866		return;
2867	}
2868
2869	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_FENCE_IO) {
2870		dout("do_request metadata corrupted\n");
2871		err = -EIO;
2872		goto finish;
2873	}
2874	if (req->r_timeout &&
2875	    time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2876		dout("do_request timed out\n");
2877		err = -ETIMEDOUT;
2878		goto finish;
2879	}
2880	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2881		dout("do_request forced umount\n");
2882		err = -EIO;
2883		goto finish;
2884	}
2885	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2886		if (mdsc->mdsmap_err) {
2887			err = mdsc->mdsmap_err;
2888			dout("do_request mdsmap err %d\n", err);
2889			goto finish;
2890		}
2891		if (mdsc->mdsmap->m_epoch == 0) {
2892			dout("do_request no mdsmap, waiting for map\n");
2893			list_add(&req->r_wait, &mdsc->waiting_for_map);
2894			return;
2895		}
2896		if (!(mdsc->fsc->mount_options->flags &
2897		      CEPH_MOUNT_OPT_MOUNTWAIT) &&
2898		    !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2899			err = -EHOSTUNREACH;
2900			goto finish;
2901		}
2902	}
2903
2904	put_request_session(req);
2905
2906	mds = __choose_mds(mdsc, req, &random);
2907	if (mds < 0 ||
2908	    ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2909		if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2910			err = -EJUKEBOX;
2911			goto finish;
2912		}
2913		dout("do_request no mds or not active, waiting for map\n");
2914		list_add(&req->r_wait, &mdsc->waiting_for_map);
2915		return;
2916	}
2917
2918	/* get, open session */
2919	session = __ceph_lookup_mds_session(mdsc, mds);
2920	if (!session) {
2921		session = register_session(mdsc, mds);
2922		if (IS_ERR(session)) {
2923			err = PTR_ERR(session);
2924			goto finish;
2925		}
2926	}
2927	req->r_session = ceph_get_mds_session(session);
2928
2929	dout("do_request mds%d session %p state %s\n", mds, session,
2930	     ceph_session_state_name(session->s_state));
2931
2932	/*
2933	 * The old ceph will crash the MDSs when see unknown OPs
2934	 */
2935	if (req->r_feature_needed > 0 &&
2936	    !test_bit(req->r_feature_needed, &session->s_features)) {
2937		err = -EOPNOTSUPP;
2938		goto out_session;
2939	}
2940
2941	if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2942	    session->s_state != CEPH_MDS_SESSION_HUNG) {
2943		/*
2944		 * We cannot queue async requests since the caps and delegated
2945		 * inodes are bound to the session. Just return -EJUKEBOX and
2946		 * let the caller retry a sync request in that case.
2947		 */
2948		if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2949			err = -EJUKEBOX;
2950			goto out_session;
2951		}
2952
2953		/*
2954		 * If the session has been REJECTED, then return a hard error,
2955		 * unless it's a CLEANRECOVER mount, in which case we'll queue
2956		 * it to the mdsc queue.
2957		 */
2958		if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2959			if (ceph_test_mount_opt(mdsc->fsc, CLEANRECOVER))
2960				list_add(&req->r_wait, &mdsc->waiting_for_map);
2961			else
2962				err = -EACCES;
2963			goto out_session;
2964		}
2965
2966		if (session->s_state == CEPH_MDS_SESSION_NEW ||
2967		    session->s_state == CEPH_MDS_SESSION_CLOSING) {
2968			err = __open_session(mdsc, session);
2969			if (err)
2970				goto out_session;
2971			/* retry the same mds later */
2972			if (random)
2973				req->r_resend_mds = mds;
2974		}
2975		list_add(&req->r_wait, &session->s_waiting);
2976		goto out_session;
2977	}
2978
2979	/* send request */
2980	req->r_resend_mds = -1;   /* forget any previous mds hint */
2981
2982	if (req->r_request_started == 0)   /* note request start time */
2983		req->r_request_started = jiffies;
2984
2985	/*
2986	 * For async create we will choose the auth MDS of frag in parent
2987	 * directory to send the request and ususally this works fine, but
2988	 * if the migrated the dirtory to another MDS before it could handle
2989	 * it the request will be forwarded.
2990	 *
2991	 * And then the auth cap will be changed.
2992	 */
2993	if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags) && req->r_num_fwd) {
2994		struct ceph_dentry_info *di = ceph_dentry(req->r_dentry);
2995		struct ceph_inode_info *ci;
2996		struct ceph_cap *cap;
2997
2998		/*
2999		 * The request maybe handled very fast and the new inode
3000		 * hasn't been linked to the dentry yet. We need to wait
3001		 * for the ceph_finish_async_create(), which shouldn't be
3002		 * stuck too long or fail in thoery, to finish when forwarding
3003		 * the request.
3004		 */
3005		if (!d_inode(req->r_dentry)) {
3006			err = wait_on_bit(&di->flags, CEPH_DENTRY_ASYNC_CREATE_BIT,
3007					  TASK_KILLABLE);
3008			if (err) {
3009				mutex_lock(&req->r_fill_mutex);
3010				set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
3011				mutex_unlock(&req->r_fill_mutex);
3012				goto out_session;
3013			}
3014		}
3015
3016		ci = ceph_inode(d_inode(req->r_dentry));
3017
3018		spin_lock(&ci->i_ceph_lock);
3019		cap = ci->i_auth_cap;
3020		if (ci->i_ceph_flags & CEPH_I_ASYNC_CREATE && mds != cap->mds) {
3021			dout("do_request session changed for auth cap %d -> %d\n",
3022			     cap->session->s_mds, session->s_mds);
3023
3024			/* Remove the auth cap from old session */
3025			spin_lock(&cap->session->s_cap_lock);
3026			cap->session->s_nr_caps--;
3027			list_del_init(&cap->session_caps);
3028			spin_unlock(&cap->session->s_cap_lock);
3029
3030			/* Add the auth cap to the new session */
3031			cap->mds = mds;
3032			cap->session = session;
3033			spin_lock(&session->s_cap_lock);
3034			session->s_nr_caps++;
3035			list_add_tail(&cap->session_caps, &session->s_caps);
3036			spin_unlock(&session->s_cap_lock);
3037
3038			change_auth_cap_ses(ci, session);
3039		}
3040		spin_unlock(&ci->i_ceph_lock);
3041	}
3042
3043	err = __send_request(session, req, false);
3044
3045out_session:
3046	ceph_put_mds_session(session);
3047finish:
3048	if (err) {
3049		dout("__do_request early error %d\n", err);
3050		req->r_err = err;
3051		complete_request(mdsc, req);
3052		__unregister_request(mdsc, req);
3053	}
3054	return;
3055}
3056
3057/*
3058 * called under mdsc->mutex
3059 */
3060static void __wake_requests(struct ceph_mds_client *mdsc,
3061			    struct list_head *head)
3062{
3063	struct ceph_mds_request *req;
3064	LIST_HEAD(tmp_list);
3065
3066	list_splice_init(head, &tmp_list);
3067
3068	while (!list_empty(&tmp_list)) {
3069		req = list_entry(tmp_list.next,
3070				 struct ceph_mds_request, r_wait);
3071		list_del_init(&req->r_wait);
3072		dout(" wake request %p tid %llu\n", req, req->r_tid);
3073		__do_request(mdsc, req);
3074	}
3075}
3076
3077/*
3078 * Wake up threads with requests pending for @mds, so that they can
3079 * resubmit their requests to a possibly different mds.
3080 */
3081static void kick_requests(struct ceph_mds_client *mdsc, int mds)
3082{
3083	struct ceph_mds_request *req;
3084	struct rb_node *p = rb_first(&mdsc->request_tree);
3085
3086	dout("kick_requests mds%d\n", mds);
3087	while (p) {
3088		req = rb_entry(p, struct ceph_mds_request, r_node);
3089		p = rb_next(p);
3090		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3091			continue;
3092		if (req->r_attempts > 0)
3093			continue; /* only new requests */
3094		if (req->r_session &&
3095		    req->r_session->s_mds == mds) {
3096			dout(" kicking tid %llu\n", req->r_tid);
3097			list_del_init(&req->r_wait);
3098			__do_request(mdsc, req);
3099		}
3100	}
3101}
3102
3103int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
3104			      struct ceph_mds_request *req)
3105{
3106	int err = 0;
3107
3108	/* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
3109	if (req->r_inode)
3110		ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
3111	if (req->r_parent) {
3112		struct ceph_inode_info *ci = ceph_inode(req->r_parent);
3113		int fmode = (req->r_op & CEPH_MDS_OP_WRITE) ?
3114			    CEPH_FILE_MODE_WR : CEPH_FILE_MODE_RD;
3115		spin_lock(&ci->i_ceph_lock);
3116		ceph_take_cap_refs(ci, CEPH_CAP_PIN, false);
3117		__ceph_touch_fmode(ci, mdsc, fmode);
3118		spin_unlock(&ci->i_ceph_lock);
3119	}
3120	if (req->r_old_dentry_dir)
3121		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
3122				  CEPH_CAP_PIN);
3123
3124	if (req->r_inode) {
3125		err = ceph_wait_on_async_create(req->r_inode);
3126		if (err) {
3127			dout("%s: wait for async create returned: %d\n",
3128			     __func__, err);
3129			return err;
3130		}
3131	}
3132
3133	if (!err && req->r_old_inode) {
3134		err = ceph_wait_on_async_create(req->r_old_inode);
3135		if (err) {
3136			dout("%s: wait for async create returned: %d\n",
3137			     __func__, err);
3138			return err;
3139		}
3140	}
3141
3142	dout("submit_request on %p for inode %p\n", req, dir);
3143	mutex_lock(&mdsc->mutex);
3144	__register_request(mdsc, req, dir);
3145	__do_request(mdsc, req);
3146	err = req->r_err;
3147	mutex_unlock(&mdsc->mutex);
3148	return err;
3149}
3150
3151int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
3152			   struct ceph_mds_request *req,
3153			   ceph_mds_request_wait_callback_t wait_func)
3154{
3155	int err;
3156
3157	/* wait */
3158	dout("do_request waiting\n");
3159	if (wait_func) {
3160		err = wait_func(mdsc, req);
3161	} else {
3162		long timeleft = wait_for_completion_killable_timeout(
3163					&req->r_completion,
3164					ceph_timeout_jiffies(req->r_timeout));
3165		if (timeleft > 0)
3166			err = 0;
3167		else if (!timeleft)
3168			err = -ETIMEDOUT;  /* timed out */
3169		else
3170			err = timeleft;  /* killed */
3171	}
3172	dout("do_request waited, got %d\n", err);
3173	mutex_lock(&mdsc->mutex);
3174
3175	/* only abort if we didn't race with a real reply */
3176	if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
3177		err = le32_to_cpu(req->r_reply_info.head->result);
3178	} else if (err < 0) {
3179		dout("aborted request %lld with %d\n", req->r_tid, err);
3180
3181		/*
3182		 * ensure we aren't running concurrently with
3183		 * ceph_fill_trace or ceph_readdir_prepopulate, which
3184		 * rely on locks (dir mutex) held by our caller.
3185		 */
3186		mutex_lock(&req->r_fill_mutex);
3187		req->r_err = err;
3188		set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
3189		mutex_unlock(&req->r_fill_mutex);
3190
3191		if (req->r_parent &&
3192		    (req->r_op & CEPH_MDS_OP_WRITE))
3193			ceph_invalidate_dir_request(req);
3194	} else {
3195		err = req->r_err;
3196	}
3197
3198	mutex_unlock(&mdsc->mutex);
3199	return err;
3200}
3201
3202/*
3203 * Synchrously perform an mds request.  Take care of all of the
3204 * session setup, forwarding, retry details.
3205 */
3206int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
3207			 struct inode *dir,
3208			 struct ceph_mds_request *req)
3209{
3210	int err;
3211
3212	dout("do_request on %p\n", req);
3213
3214	/* issue */
3215	err = ceph_mdsc_submit_request(mdsc, dir, req);
3216	if (!err)
3217		err = ceph_mdsc_wait_request(mdsc, req, NULL);
3218	dout("do_request %p done, result %d\n", req, err);
3219	return err;
3220}
3221
3222/*
3223 * Invalidate dir's completeness, dentry lease state on an aborted MDS
3224 * namespace request.
3225 */
3226void ceph_invalidate_dir_request(struct ceph_mds_request *req)
3227{
3228	struct inode *dir = req->r_parent;
3229	struct inode *old_dir = req->r_old_dentry_dir;
3230
3231	dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
3232
3233	ceph_dir_clear_complete(dir);
3234	if (old_dir)
3235		ceph_dir_clear_complete(old_dir);
3236	if (req->r_dentry)
3237		ceph_invalidate_dentry_lease(req->r_dentry);
3238	if (req->r_old_dentry)
3239		ceph_invalidate_dentry_lease(req->r_old_dentry);
3240}
3241
3242/*
3243 * Handle mds reply.
3244 *
3245 * We take the session mutex and parse and process the reply immediately.
3246 * This preserves the logical ordering of replies, capabilities, etc., sent
3247 * by the MDS as they are applied to our local cache.
3248 */
3249static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
3250{
3251	struct ceph_mds_client *mdsc = session->s_mdsc;
3252	struct ceph_mds_request *req;
3253	struct ceph_mds_reply_head *head = msg->front.iov_base;
3254	struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
3255	struct ceph_snap_realm *realm;
3256	u64 tid;
3257	int err, result;
3258	int mds = session->s_mds;
3259	bool close_sessions = false;
3260
3261	if (msg->front.iov_len < sizeof(*head)) {
3262		pr_err("mdsc_handle_reply got corrupt (short) reply\n");
3263		ceph_msg_dump(msg);
3264		return;
3265	}
3266
3267	/* get request, session */
3268	tid = le64_to_cpu(msg->hdr.tid);
3269	mutex_lock(&mdsc->mutex);
3270	req = lookup_get_request(mdsc, tid);
3271	if (!req) {
3272		dout("handle_reply on unknown tid %llu\n", tid);
3273		mutex_unlock(&mdsc->mutex);
3274		return;
3275	}
3276	dout("handle_reply %p\n", req);
3277
3278	/* correct session? */
3279	if (req->r_session != session) {
3280		pr_err("mdsc_handle_reply got %llu on session mds%d"
3281		       " not mds%d\n", tid, session->s_mds,
3282		       req->r_session ? req->r_session->s_mds : -1);
3283		mutex_unlock(&mdsc->mutex);
3284		goto out;
3285	}
3286
3287	/* dup? */
3288	if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
3289	    (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
3290		pr_warn("got a dup %s reply on %llu from mds%d\n",
3291			   head->safe ? "safe" : "unsafe", tid, mds);
3292		mutex_unlock(&mdsc->mutex);
3293		goto out;
3294	}
3295	if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
3296		pr_warn("got unsafe after safe on %llu from mds%d\n",
3297			   tid, mds);
3298		mutex_unlock(&mdsc->mutex);
3299		goto out;
3300	}
3301
3302	result = le32_to_cpu(head->result);
3303
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3304	if (head->safe) {
3305		set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
3306		__unregister_request(mdsc, req);
3307
3308		/* last request during umount? */
3309		if (mdsc->stopping && !__get_oldest_req(mdsc))
3310			complete_all(&mdsc->safe_umount_waiters);
3311
3312		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3313			/*
3314			 * We already handled the unsafe response, now do the
3315			 * cleanup.  No need to examine the response; the MDS
3316			 * doesn't include any result info in the safe
3317			 * response.  And even if it did, there is nothing
3318			 * useful we could do with a revised return value.
3319			 */
3320			dout("got safe reply %llu, mds%d\n", tid, mds);
3321
3322			mutex_unlock(&mdsc->mutex);
3323			goto out;
3324		}
3325	} else {
3326		set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
3327		list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
3328	}
3329
3330	dout("handle_reply tid %lld result %d\n", tid, result);
3331	rinfo = &req->r_reply_info;
3332	if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
3333		err = parse_reply_info(session, msg, rinfo, (u64)-1);
3334	else
3335		err = parse_reply_info(session, msg, rinfo, session->s_con.peer_features);
3336	mutex_unlock(&mdsc->mutex);
3337
3338	/* Must find target inode outside of mutexes to avoid deadlocks */
3339	if ((err >= 0) && rinfo->head->is_target) {
3340		struct inode *in;
3341		struct ceph_vino tvino = {
3342			.ino  = le64_to_cpu(rinfo->targeti.in->ino),
3343			.snap = le64_to_cpu(rinfo->targeti.in->snapid)
3344		};
3345
3346		in = ceph_get_inode(mdsc->fsc->sb, tvino);
3347		if (IS_ERR(in)) {
3348			err = PTR_ERR(in);
3349			mutex_lock(&session->s_mutex);
3350			goto out_err;
3351		}
3352		req->r_target_inode = in;
3353	}
3354
3355	mutex_lock(&session->s_mutex);
3356	if (err < 0) {
3357		pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
3358		ceph_msg_dump(msg);
3359		goto out_err;
3360	}
3361
3362	/* snap trace */
3363	realm = NULL;
3364	if (rinfo->snapblob_len) {
3365		down_write(&mdsc->snap_rwsem);
3366		err = ceph_update_snap_trace(mdsc, rinfo->snapblob,
3367				rinfo->snapblob + rinfo->snapblob_len,
3368				le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
3369				&realm);
3370		if (err) {
3371			up_write(&mdsc->snap_rwsem);
3372			close_sessions = true;
3373			if (err == -EIO)
3374				ceph_msg_dump(msg);
3375			goto out_err;
3376		}
3377		downgrade_write(&mdsc->snap_rwsem);
3378	} else {
3379		down_read(&mdsc->snap_rwsem);
3380	}
3381
3382	/* insert trace into our cache */
3383	mutex_lock(&req->r_fill_mutex);
3384	current->journal_info = req;
3385	err = ceph_fill_trace(mdsc->fsc->sb, req);
3386	if (err == 0) {
3387		if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
3388				    req->r_op == CEPH_MDS_OP_LSSNAP))
3389			ceph_readdir_prepopulate(req, req->r_session);
3390	}
3391	current->journal_info = NULL;
3392	mutex_unlock(&req->r_fill_mutex);
3393
3394	up_read(&mdsc->snap_rwsem);
3395	if (realm)
3396		ceph_put_snap_realm(mdsc, realm);
3397
3398	if (err == 0) {
3399		if (req->r_target_inode &&
3400		    test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3401			struct ceph_inode_info *ci =
3402				ceph_inode(req->r_target_inode);
3403			spin_lock(&ci->i_unsafe_lock);
3404			list_add_tail(&req->r_unsafe_target_item,
3405				      &ci->i_unsafe_iops);
3406			spin_unlock(&ci->i_unsafe_lock);
3407		}
3408
3409		ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
3410	}
3411out_err:
3412	mutex_lock(&mdsc->mutex);
3413	if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3414		if (err) {
3415			req->r_err = err;
3416		} else {
3417			req->r_reply =  ceph_msg_get(msg);
3418			set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
3419		}
3420	} else {
3421		dout("reply arrived after request %lld was aborted\n", tid);
3422	}
3423	mutex_unlock(&mdsc->mutex);
3424
3425	mutex_unlock(&session->s_mutex);
3426
3427	/* kick calling process */
3428	complete_request(mdsc, req);
3429
3430	ceph_update_metadata_metrics(&mdsc->metric, req->r_start_latency,
3431				     req->r_end_latency, err);
3432out:
3433	ceph_mdsc_put_request(req);
3434
3435	/* Defer closing the sessions after s_mutex lock being released */
3436	if (close_sessions)
3437		ceph_mdsc_close_sessions(mdsc);
3438	return;
3439}
3440
3441
3442
3443/*
3444 * handle mds notification that our request has been forwarded.
3445 */
3446static void handle_forward(struct ceph_mds_client *mdsc,
3447			   struct ceph_mds_session *session,
3448			   struct ceph_msg *msg)
3449{
3450	struct ceph_mds_request *req;
3451	u64 tid = le64_to_cpu(msg->hdr.tid);
3452	u32 next_mds;
3453	u32 fwd_seq;
3454	int err = -EINVAL;
3455	void *p = msg->front.iov_base;
3456	void *end = p + msg->front.iov_len;
3457	bool aborted = false;
3458
3459	ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3460	next_mds = ceph_decode_32(&p);
3461	fwd_seq = ceph_decode_32(&p);
3462
3463	mutex_lock(&mdsc->mutex);
3464	req = lookup_get_request(mdsc, tid);
3465	if (!req) {
3466		mutex_unlock(&mdsc->mutex);
3467		dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3468		return;  /* dup reply? */
3469	}
3470
3471	if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3472		dout("forward tid %llu aborted, unregistering\n", tid);
3473		__unregister_request(mdsc, req);
3474	} else if (fwd_seq <= req->r_num_fwd) {
3475		/*
3476		 * The type of 'num_fwd' in ceph 'MClientRequestForward'
3477		 * is 'int32_t', while in 'ceph_mds_request_head' the
3478		 * type is '__u8'. So in case the request bounces between
3479		 * MDSes exceeding 256 times, the client will get stuck.
3480		 *
3481		 * In this case it's ususally a bug in MDS and continue
3482		 * bouncing the request makes no sense.
3483		 *
3484		 * In future this could be fixed in ceph code, so avoid
3485		 * using the hardcode here.
3486		 */
3487		int max = sizeof_field(struct ceph_mds_request_head, num_fwd);
3488		max = 1 << (max * BITS_PER_BYTE);
3489		if (req->r_num_fwd >= max) {
3490			mutex_lock(&req->r_fill_mutex);
3491			req->r_err = -EMULTIHOP;
3492			set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
3493			mutex_unlock(&req->r_fill_mutex);
3494			aborted = true;
3495			pr_warn_ratelimited("forward tid %llu seq overflow\n",
3496					    tid);
3497		} else {
3498			dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3499			     tid, next_mds, req->r_num_fwd, fwd_seq);
3500		}
3501	} else {
3502		/* resend. forward race not possible; mds would drop */
3503		dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3504		BUG_ON(req->r_err);
3505		BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3506		req->r_attempts = 0;
3507		req->r_num_fwd = fwd_seq;
3508		req->r_resend_mds = next_mds;
3509		put_request_session(req);
3510		__do_request(mdsc, req);
3511	}
3512	mutex_unlock(&mdsc->mutex);
3513
3514	/* kick calling process */
3515	if (aborted)
3516		complete_request(mdsc, req);
3517	ceph_mdsc_put_request(req);
 
 
3518	return;
3519
3520bad:
3521	pr_err("mdsc_handle_forward decode error err=%d\n", err);
3522}
3523
3524static int __decode_session_metadata(void **p, void *end,
3525				     bool *blocklisted)
3526{
3527	/* map<string,string> */
3528	u32 n;
3529	bool err_str;
3530	ceph_decode_32_safe(p, end, n, bad);
3531	while (n-- > 0) {
3532		u32 len;
3533		ceph_decode_32_safe(p, end, len, bad);
3534		ceph_decode_need(p, end, len, bad);
3535		err_str = !strncmp(*p, "error_string", len);
3536		*p += len;
3537		ceph_decode_32_safe(p, end, len, bad);
3538		ceph_decode_need(p, end, len, bad);
3539		/*
3540		 * Match "blocklisted (blacklisted)" from newer MDSes,
3541		 * or "blacklisted" from older MDSes.
3542		 */
3543		if (err_str && strnstr(*p, "blacklisted", len))
3544			*blocklisted = true;
3545		*p += len;
3546	}
3547	return 0;
3548bad:
3549	return -1;
3550}
3551
3552/*
3553 * handle a mds session control message
3554 */
3555static void handle_session(struct ceph_mds_session *session,
3556			   struct ceph_msg *msg)
3557{
3558	struct ceph_mds_client *mdsc = session->s_mdsc;
3559	int mds = session->s_mds;
3560	int msg_version = le16_to_cpu(msg->hdr.version);
3561	void *p = msg->front.iov_base;
3562	void *end = p + msg->front.iov_len;
3563	struct ceph_mds_session_head *h;
3564	u32 op;
3565	u64 seq, features = 0;
3566	int wake = 0;
3567	bool blocklisted = false;
3568
3569	/* decode */
3570	ceph_decode_need(&p, end, sizeof(*h), bad);
3571	h = p;
3572	p += sizeof(*h);
3573
3574	op = le32_to_cpu(h->op);
3575	seq = le64_to_cpu(h->seq);
3576
3577	if (msg_version >= 3) {
3578		u32 len;
3579		/* version >= 2 and < 5, decode metadata, skip otherwise
3580		 * as it's handled via flags.
3581		 */
3582		if (msg_version >= 5)
3583			ceph_decode_skip_map(&p, end, string, string, bad);
3584		else if (__decode_session_metadata(&p, end, &blocklisted) < 0)
3585			goto bad;
3586
3587		/* version >= 3, feature bits */
3588		ceph_decode_32_safe(&p, end, len, bad);
3589		if (len) {
3590			ceph_decode_64_safe(&p, end, features, bad);
3591			p += len - sizeof(features);
3592		}
3593	}
3594
3595	if (msg_version >= 5) {
3596		u32 flags, len;
3597
3598		/* version >= 4 */
3599		ceph_decode_skip_16(&p, end, bad); /* struct_v, struct_cv */
3600		ceph_decode_32_safe(&p, end, len, bad); /* len */
3601		ceph_decode_skip_n(&p, end, len, bad); /* metric_spec */
3602
3603		/* version >= 5, flags   */
3604		ceph_decode_32_safe(&p, end, flags, bad);
3605		if (flags & CEPH_SESSION_BLOCKLISTED) {
3606			pr_warn("mds%d session blocklisted\n", session->s_mds);
3607			blocklisted = true;
3608		}
3609	}
3610
3611	mutex_lock(&mdsc->mutex);
3612	if (op == CEPH_SESSION_CLOSE) {
3613		ceph_get_mds_session(session);
3614		__unregister_session(mdsc, session);
3615	}
3616	/* FIXME: this ttl calculation is generous */
3617	session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3618	mutex_unlock(&mdsc->mutex);
3619
3620	mutex_lock(&session->s_mutex);
3621
3622	dout("handle_session mds%d %s %p state %s seq %llu\n",
3623	     mds, ceph_session_op_name(op), session,
3624	     ceph_session_state_name(session->s_state), seq);
3625
3626	if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3627		session->s_state = CEPH_MDS_SESSION_OPEN;
3628		pr_info("mds%d came back\n", session->s_mds);
3629	}
3630
3631	switch (op) {
3632	case CEPH_SESSION_OPEN:
3633		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3634			pr_info("mds%d reconnect success\n", session->s_mds);
3635
3636		if (session->s_state == CEPH_MDS_SESSION_OPEN) {
3637			pr_notice("mds%d is already opened\n", session->s_mds);
3638		} else {
3639			session->s_state = CEPH_MDS_SESSION_OPEN;
3640			session->s_features = features;
3641			renewed_caps(mdsc, session, 0);
3642			if (test_bit(CEPHFS_FEATURE_METRIC_COLLECT,
3643				     &session->s_features))
3644				metric_schedule_delayed(&mdsc->metric);
3645		}
3646
3647		/*
3648		 * The connection maybe broken and the session in client
3649		 * side has been reinitialized, need to update the seq
3650		 * anyway.
3651		 */
3652		if (!session->s_seq && seq)
3653			session->s_seq = seq;
3654
3655		wake = 1;
3656		if (mdsc->stopping)
3657			__close_session(mdsc, session);
3658		break;
3659
3660	case CEPH_SESSION_RENEWCAPS:
3661		if (session->s_renew_seq == seq)
3662			renewed_caps(mdsc, session, 1);
3663		break;
3664
3665	case CEPH_SESSION_CLOSE:
3666		if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3667			pr_info("mds%d reconnect denied\n", session->s_mds);
3668		session->s_state = CEPH_MDS_SESSION_CLOSED;
3669		cleanup_session_requests(mdsc, session);
3670		remove_session_caps(session);
3671		wake = 2; /* for good measure */
3672		wake_up_all(&mdsc->session_close_wq);
3673		break;
3674
3675	case CEPH_SESSION_STALE:
3676		pr_info("mds%d caps went stale, renewing\n",
3677			session->s_mds);
3678		atomic_inc(&session->s_cap_gen);
3679		session->s_cap_ttl = jiffies - 1;
3680		send_renew_caps(mdsc, session);
3681		break;
3682
3683	case CEPH_SESSION_RECALL_STATE:
3684		ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3685		break;
3686
3687	case CEPH_SESSION_FLUSHMSG:
3688		/* flush cap releases */
3689		spin_lock(&session->s_cap_lock);
3690		if (session->s_num_cap_releases)
3691			ceph_flush_cap_releases(mdsc, session);
3692		spin_unlock(&session->s_cap_lock);
3693
3694		send_flushmsg_ack(mdsc, session, seq);
3695		break;
3696
3697	case CEPH_SESSION_FORCE_RO:
3698		dout("force_session_readonly %p\n", session);
3699		spin_lock(&session->s_cap_lock);
3700		session->s_readonly = true;
3701		spin_unlock(&session->s_cap_lock);
3702		wake_up_session_caps(session, FORCE_RO);
3703		break;
3704
3705	case CEPH_SESSION_REJECT:
3706		WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3707		pr_info("mds%d rejected session\n", session->s_mds);
3708		session->s_state = CEPH_MDS_SESSION_REJECTED;
3709		cleanup_session_requests(mdsc, session);
3710		remove_session_caps(session);
3711		if (blocklisted)
3712			mdsc->fsc->blocklisted = true;
3713		wake = 2; /* for good measure */
3714		break;
3715
3716	default:
3717		pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3718		WARN_ON(1);
3719	}
3720
3721	mutex_unlock(&session->s_mutex);
3722	if (wake) {
3723		mutex_lock(&mdsc->mutex);
3724		__wake_requests(mdsc, &session->s_waiting);
3725		if (wake == 2)
3726			kick_requests(mdsc, mds);
3727		mutex_unlock(&mdsc->mutex);
3728	}
3729	if (op == CEPH_SESSION_CLOSE)
3730		ceph_put_mds_session(session);
3731	return;
3732
3733bad:
3734	pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3735	       (int)msg->front.iov_len);
3736	ceph_msg_dump(msg);
3737	return;
3738}
3739
3740void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req)
3741{
3742	int dcaps;
3743
3744	dcaps = xchg(&req->r_dir_caps, 0);
3745	if (dcaps) {
3746		dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3747		ceph_put_cap_refs(ceph_inode(req->r_parent), dcaps);
3748	}
3749}
3750
3751void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req)
3752{
3753	int dcaps;
3754
3755	dcaps = xchg(&req->r_dir_caps, 0);
3756	if (dcaps) {
3757		dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3758		ceph_put_cap_refs_no_check_caps(ceph_inode(req->r_parent),
3759						dcaps);
3760	}
3761}
3762
3763/*
3764 * called under session->mutex.
3765 */
3766static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3767				   struct ceph_mds_session *session)
3768{
3769	struct ceph_mds_request *req, *nreq;
3770	struct rb_node *p;
3771
3772	dout("replay_unsafe_requests mds%d\n", session->s_mds);
3773
3774	mutex_lock(&mdsc->mutex);
3775	list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item)
3776		__send_request(session, req, true);
3777
3778	/*
3779	 * also re-send old requests when MDS enters reconnect stage. So that MDS
3780	 * can process completed request in clientreplay stage.
3781	 */
3782	p = rb_first(&mdsc->request_tree);
3783	while (p) {
3784		req = rb_entry(p, struct ceph_mds_request, r_node);
3785		p = rb_next(p);
3786		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3787			continue;
3788		if (req->r_attempts == 0)
3789			continue; /* only old requests */
3790		if (!req->r_session)
3791			continue;
3792		if (req->r_session->s_mds != session->s_mds)
3793			continue;
3794
3795		ceph_mdsc_release_dir_caps_no_check(req);
3796
3797		__send_request(session, req, true);
3798	}
3799	mutex_unlock(&mdsc->mutex);
3800}
3801
3802static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3803{
3804	struct ceph_msg *reply;
3805	struct ceph_pagelist *_pagelist;
3806	struct page *page;
3807	__le32 *addr;
3808	int err = -ENOMEM;
3809
3810	if (!recon_state->allow_multi)
3811		return -ENOSPC;
3812
3813	/* can't handle message that contains both caps and realm */
3814	BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3815
3816	/* pre-allocate new pagelist */
3817	_pagelist = ceph_pagelist_alloc(GFP_NOFS);
3818	if (!_pagelist)
3819		return -ENOMEM;
3820
3821	reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3822	if (!reply)
3823		goto fail_msg;
3824
3825	/* placeholder for nr_caps */
3826	err = ceph_pagelist_encode_32(_pagelist, 0);
3827	if (err < 0)
3828		goto fail;
3829
3830	if (recon_state->nr_caps) {
3831		/* currently encoding caps */
3832		err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3833		if (err)
3834			goto fail;
3835	} else {
3836		/* placeholder for nr_realms (currently encoding relams) */
3837		err = ceph_pagelist_encode_32(_pagelist, 0);
3838		if (err < 0)
3839			goto fail;
3840	}
3841
3842	err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3843	if (err)
3844		goto fail;
3845
3846	page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3847	addr = kmap_atomic(page);
3848	if (recon_state->nr_caps) {
3849		/* currently encoding caps */
3850		*addr = cpu_to_le32(recon_state->nr_caps);
3851	} else {
3852		/* currently encoding relams */
3853		*(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3854	}
3855	kunmap_atomic(addr);
3856
3857	reply->hdr.version = cpu_to_le16(5);
3858	reply->hdr.compat_version = cpu_to_le16(4);
3859
3860	reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3861	ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3862
3863	ceph_con_send(&recon_state->session->s_con, reply);
3864	ceph_pagelist_release(recon_state->pagelist);
3865
3866	recon_state->pagelist = _pagelist;
3867	recon_state->nr_caps = 0;
3868	recon_state->nr_realms = 0;
3869	recon_state->msg_version = 5;
3870	return 0;
3871fail:
3872	ceph_msg_put(reply);
3873fail_msg:
3874	ceph_pagelist_release(_pagelist);
3875	return err;
3876}
3877
3878static struct dentry* d_find_primary(struct inode *inode)
3879{
3880	struct dentry *alias, *dn = NULL;
3881
3882	if (hlist_empty(&inode->i_dentry))
3883		return NULL;
3884
3885	spin_lock(&inode->i_lock);
3886	if (hlist_empty(&inode->i_dentry))
3887		goto out_unlock;
3888
3889	if (S_ISDIR(inode->i_mode)) {
3890		alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
3891		if (!IS_ROOT(alias))
3892			dn = dget(alias);
3893		goto out_unlock;
3894	}
3895
3896	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
3897		spin_lock(&alias->d_lock);
3898		if (!d_unhashed(alias) &&
3899		    (ceph_dentry(alias)->flags & CEPH_DENTRY_PRIMARY_LINK)) {
3900			dn = dget_dlock(alias);
3901		}
3902		spin_unlock(&alias->d_lock);
3903		if (dn)
3904			break;
3905	}
3906out_unlock:
3907	spin_unlock(&inode->i_lock);
3908	return dn;
3909}
3910
3911/*
3912 * Encode information about a cap for a reconnect with the MDS.
3913 */
3914static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
3915			  void *arg)
3916{
3917	union {
3918		struct ceph_mds_cap_reconnect v2;
3919		struct ceph_mds_cap_reconnect_v1 v1;
3920	} rec;
3921	struct ceph_inode_info *ci = cap->ci;
3922	struct ceph_reconnect_state *recon_state = arg;
3923	struct ceph_pagelist *pagelist = recon_state->pagelist;
3924	struct dentry *dentry;
3925	char *path;
3926	int pathlen = 0, err;
3927	u64 pathbase;
3928	u64 snap_follows;
3929
3930	dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3931	     inode, ceph_vinop(inode), cap, cap->cap_id,
3932	     ceph_cap_string(cap->issued));
3933
3934	dentry = d_find_primary(inode);
3935	if (dentry) {
3936		/* set pathbase to parent dir when msg_version >= 2 */
3937		path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase,
3938					    recon_state->msg_version >= 2);
3939		dput(dentry);
3940		if (IS_ERR(path)) {
3941			err = PTR_ERR(path);
3942			goto out_err;
3943		}
3944	} else {
3945		path = NULL;
 
3946		pathbase = 0;
3947	}
3948
3949	spin_lock(&ci->i_ceph_lock);
3950	cap->seq = 0;        /* reset cap seq */
3951	cap->issue_seq = 0;  /* and issue_seq */
3952	cap->mseq = 0;       /* and migrate_seq */
3953	cap->cap_gen = atomic_read(&cap->session->s_cap_gen);
3954
3955	/* These are lost when the session goes away */
3956	if (S_ISDIR(inode->i_mode)) {
3957		if (cap->issued & CEPH_CAP_DIR_CREATE) {
3958			ceph_put_string(rcu_dereference_raw(ci->i_cached_layout.pool_ns));
3959			memset(&ci->i_cached_layout, 0, sizeof(ci->i_cached_layout));
3960		}
3961		cap->issued &= ~CEPH_CAP_ANY_DIR_OPS;
3962	}
3963
3964	if (recon_state->msg_version >= 2) {
3965		rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3966		rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3967		rec.v2.issued = cpu_to_le32(cap->issued);
3968		rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3969		rec.v2.pathbase = cpu_to_le64(pathbase);
3970		rec.v2.flock_len = (__force __le32)
3971			((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3972	} else {
3973		rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3974		rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3975		rec.v1.issued = cpu_to_le32(cap->issued);
3976		rec.v1.size = cpu_to_le64(i_size_read(inode));
3977		ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3978		ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3979		rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3980		rec.v1.pathbase = cpu_to_le64(pathbase);
3981	}
3982
3983	if (list_empty(&ci->i_cap_snaps)) {
3984		snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3985	} else {
3986		struct ceph_cap_snap *capsnap =
3987			list_first_entry(&ci->i_cap_snaps,
3988					 struct ceph_cap_snap, ci_item);
3989		snap_follows = capsnap->follows;
3990	}
3991	spin_unlock(&ci->i_ceph_lock);
3992
3993	if (recon_state->msg_version >= 2) {
3994		int num_fcntl_locks, num_flock_locks;
3995		struct ceph_filelock *flocks = NULL;
3996		size_t struct_len, total_len = sizeof(u64);
3997		u8 struct_v = 0;
3998
3999encode_again:
4000		if (rec.v2.flock_len) {
4001			ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
4002		} else {
4003			num_fcntl_locks = 0;
4004			num_flock_locks = 0;
4005		}
4006		if (num_fcntl_locks + num_flock_locks > 0) {
4007			flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
4008					       sizeof(struct ceph_filelock),
4009					       GFP_NOFS);
4010			if (!flocks) {
4011				err = -ENOMEM;
4012				goto out_err;
4013			}
4014			err = ceph_encode_locks_to_buffer(inode, flocks,
4015							  num_fcntl_locks,
4016							  num_flock_locks);
4017			if (err) {
4018				kfree(flocks);
4019				flocks = NULL;
4020				if (err == -ENOSPC)
4021					goto encode_again;
4022				goto out_err;
4023			}
4024		} else {
4025			kfree(flocks);
4026			flocks = NULL;
4027		}
4028
4029		if (recon_state->msg_version >= 3) {
4030			/* version, compat_version and struct_len */
4031			total_len += 2 * sizeof(u8) + sizeof(u32);
4032			struct_v = 2;
4033		}
4034		/*
4035		 * number of encoded locks is stable, so copy to pagelist
4036		 */
4037		struct_len = 2 * sizeof(u32) +
4038			    (num_fcntl_locks + num_flock_locks) *
4039			    sizeof(struct ceph_filelock);
4040		rec.v2.flock_len = cpu_to_le32(struct_len);
4041
4042		struct_len += sizeof(u32) + pathlen + sizeof(rec.v2);
4043
4044		if (struct_v >= 2)
4045			struct_len += sizeof(u64); /* snap_follows */
4046
4047		total_len += struct_len;
4048
4049		if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
4050			err = send_reconnect_partial(recon_state);
4051			if (err)
4052				goto out_freeflocks;
4053			pagelist = recon_state->pagelist;
4054		}
4055
4056		err = ceph_pagelist_reserve(pagelist, total_len);
4057		if (err)
4058			goto out_freeflocks;
4059
4060		ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
4061		if (recon_state->msg_version >= 3) {
4062			ceph_pagelist_encode_8(pagelist, struct_v);
4063			ceph_pagelist_encode_8(pagelist, 1);
4064			ceph_pagelist_encode_32(pagelist, struct_len);
4065		}
4066		ceph_pagelist_encode_string(pagelist, path, pathlen);
4067		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
4068		ceph_locks_to_pagelist(flocks, pagelist,
4069				       num_fcntl_locks, num_flock_locks);
4070		if (struct_v >= 2)
4071			ceph_pagelist_encode_64(pagelist, snap_follows);
4072out_freeflocks:
4073		kfree(flocks);
4074	} else {
4075		err = ceph_pagelist_reserve(pagelist,
4076					    sizeof(u64) + sizeof(u32) +
4077					    pathlen + sizeof(rec.v1));
4078		if (err)
4079			goto out_err;
4080
4081		ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
4082		ceph_pagelist_encode_string(pagelist, path, pathlen);
4083		ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
4084	}
4085
4086out_err:
4087	ceph_mdsc_free_path(path, pathlen);
4088	if (!err)
4089		recon_state->nr_caps++;
4090	return err;
4091}
4092
4093static int encode_snap_realms(struct ceph_mds_client *mdsc,
4094			      struct ceph_reconnect_state *recon_state)
4095{
4096	struct rb_node *p;
4097	struct ceph_pagelist *pagelist = recon_state->pagelist;
4098	int err = 0;
4099
4100	if (recon_state->msg_version >= 4) {
4101		err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
4102		if (err < 0)
4103			goto fail;
4104	}
4105
4106	/*
4107	 * snaprealms.  we provide mds with the ino, seq (version), and
4108	 * parent for all of our realms.  If the mds has any newer info,
4109	 * it will tell us.
4110	 */
4111	for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
4112		struct ceph_snap_realm *realm =
4113		       rb_entry(p, struct ceph_snap_realm, node);
4114		struct ceph_mds_snaprealm_reconnect sr_rec;
4115
4116		if (recon_state->msg_version >= 4) {
4117			size_t need = sizeof(u8) * 2 + sizeof(u32) +
4118				      sizeof(sr_rec);
4119
4120			if (pagelist->length + need > RECONNECT_MAX_SIZE) {
4121				err = send_reconnect_partial(recon_state);
4122				if (err)
4123					goto fail;
4124				pagelist = recon_state->pagelist;
4125			}
4126
4127			err = ceph_pagelist_reserve(pagelist, need);
4128			if (err)
4129				goto fail;
4130
4131			ceph_pagelist_encode_8(pagelist, 1);
4132			ceph_pagelist_encode_8(pagelist, 1);
4133			ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
4134		}
4135
4136		dout(" adding snap realm %llx seq %lld parent %llx\n",
4137		     realm->ino, realm->seq, realm->parent_ino);
4138		sr_rec.ino = cpu_to_le64(realm->ino);
4139		sr_rec.seq = cpu_to_le64(realm->seq);
4140		sr_rec.parent = cpu_to_le64(realm->parent_ino);
4141
4142		err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
4143		if (err)
4144			goto fail;
4145
4146		recon_state->nr_realms++;
4147	}
4148fail:
4149	return err;
4150}
4151
4152
4153/*
4154 * If an MDS fails and recovers, clients need to reconnect in order to
4155 * reestablish shared state.  This includes all caps issued through
4156 * this session _and_ the snap_realm hierarchy.  Because it's not
4157 * clear which snap realms the mds cares about, we send everything we
4158 * know about.. that ensures we'll then get any new info the
4159 * recovering MDS might have.
4160 *
4161 * This is a relatively heavyweight operation, but it's rare.
4162 */
4163static void send_mds_reconnect(struct ceph_mds_client *mdsc,
4164			       struct ceph_mds_session *session)
4165{
4166	struct ceph_msg *reply;
4167	int mds = session->s_mds;
4168	int err = -ENOMEM;
4169	struct ceph_reconnect_state recon_state = {
4170		.session = session,
4171	};
4172	LIST_HEAD(dispose);
4173
4174	pr_info("mds%d reconnect start\n", mds);
4175
4176	recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
4177	if (!recon_state.pagelist)
4178		goto fail_nopagelist;
4179
4180	reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
4181	if (!reply)
4182		goto fail_nomsg;
4183
4184	xa_destroy(&session->s_delegated_inos);
4185
4186	mutex_lock(&session->s_mutex);
4187	session->s_state = CEPH_MDS_SESSION_RECONNECTING;
4188	session->s_seq = 0;
4189
4190	dout("session %p state %s\n", session,
4191	     ceph_session_state_name(session->s_state));
4192
4193	atomic_inc(&session->s_cap_gen);
4194
4195	spin_lock(&session->s_cap_lock);
4196	/* don't know if session is readonly */
4197	session->s_readonly = 0;
4198	/*
4199	 * notify __ceph_remove_cap() that we are composing cap reconnect.
4200	 * If a cap get released before being added to the cap reconnect,
4201	 * __ceph_remove_cap() should skip queuing cap release.
4202	 */
4203	session->s_cap_reconnect = 1;
4204	/* drop old cap expires; we're about to reestablish that state */
4205	detach_cap_releases(session, &dispose);
4206	spin_unlock(&session->s_cap_lock);
4207	dispose_cap_releases(mdsc, &dispose);
4208
4209	/* trim unused caps to reduce MDS's cache rejoin time */
4210	if (mdsc->fsc->sb->s_root)
4211		shrink_dcache_parent(mdsc->fsc->sb->s_root);
4212
4213	ceph_con_close(&session->s_con);
4214	ceph_con_open(&session->s_con,
4215		      CEPH_ENTITY_TYPE_MDS, mds,
4216		      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
4217
4218	/* replay unsafe requests */
4219	replay_unsafe_requests(mdsc, session);
4220
4221	ceph_early_kick_flushing_caps(mdsc, session);
4222
4223	down_read(&mdsc->snap_rwsem);
4224
4225	/* placeholder for nr_caps */
4226	err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
4227	if (err)
4228		goto fail;
4229
4230	if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
4231		recon_state.msg_version = 3;
4232		recon_state.allow_multi = true;
4233	} else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
4234		recon_state.msg_version = 3;
4235	} else {
4236		recon_state.msg_version = 2;
4237	}
4238	/* trsaverse this session's caps */
4239	err = ceph_iterate_session_caps(session, reconnect_caps_cb, &recon_state);
4240
4241	spin_lock(&session->s_cap_lock);
4242	session->s_cap_reconnect = 0;
4243	spin_unlock(&session->s_cap_lock);
4244
4245	if (err < 0)
4246		goto fail;
4247
4248	/* check if all realms can be encoded into current message */
4249	if (mdsc->num_snap_realms) {
4250		size_t total_len =
4251			recon_state.pagelist->length +
4252			mdsc->num_snap_realms *
4253			sizeof(struct ceph_mds_snaprealm_reconnect);
4254		if (recon_state.msg_version >= 4) {
4255			/* number of realms */
4256			total_len += sizeof(u32);
4257			/* version, compat_version and struct_len */
4258			total_len += mdsc->num_snap_realms *
4259				     (2 * sizeof(u8) + sizeof(u32));
4260		}
4261		if (total_len > RECONNECT_MAX_SIZE) {
4262			if (!recon_state.allow_multi) {
4263				err = -ENOSPC;
4264				goto fail;
4265			}
4266			if (recon_state.nr_caps) {
4267				err = send_reconnect_partial(&recon_state);
4268				if (err)
4269					goto fail;
4270			}
4271			recon_state.msg_version = 5;
4272		}
4273	}
4274
4275	err = encode_snap_realms(mdsc, &recon_state);
4276	if (err < 0)
4277		goto fail;
4278
4279	if (recon_state.msg_version >= 5) {
4280		err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
4281		if (err < 0)
4282			goto fail;
4283	}
4284
4285	if (recon_state.nr_caps || recon_state.nr_realms) {
4286		struct page *page =
4287			list_first_entry(&recon_state.pagelist->head,
4288					struct page, lru);
4289		__le32 *addr = kmap_atomic(page);
4290		if (recon_state.nr_caps) {
4291			WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
4292			*addr = cpu_to_le32(recon_state.nr_caps);
4293		} else if (recon_state.msg_version >= 4) {
4294			*(addr + 1) = cpu_to_le32(recon_state.nr_realms);
4295		}
4296		kunmap_atomic(addr);
4297	}
4298
4299	reply->hdr.version = cpu_to_le16(recon_state.msg_version);
4300	if (recon_state.msg_version >= 4)
4301		reply->hdr.compat_version = cpu_to_le16(4);
4302
4303	reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
4304	ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
4305
4306	ceph_con_send(&session->s_con, reply);
4307
4308	mutex_unlock(&session->s_mutex);
4309
4310	mutex_lock(&mdsc->mutex);
4311	__wake_requests(mdsc, &session->s_waiting);
4312	mutex_unlock(&mdsc->mutex);
4313
4314	up_read(&mdsc->snap_rwsem);
4315	ceph_pagelist_release(recon_state.pagelist);
4316	return;
4317
4318fail:
4319	ceph_msg_put(reply);
4320	up_read(&mdsc->snap_rwsem);
4321	mutex_unlock(&session->s_mutex);
4322fail_nomsg:
4323	ceph_pagelist_release(recon_state.pagelist);
4324fail_nopagelist:
4325	pr_err("error %d preparing reconnect for mds%d\n", err, mds);
4326	return;
4327}
4328
4329
4330/*
4331 * compare old and new mdsmaps, kicking requests
4332 * and closing out old connections as necessary
4333 *
4334 * called under mdsc->mutex.
4335 */
4336static void check_new_map(struct ceph_mds_client *mdsc,
4337			  struct ceph_mdsmap *newmap,
4338			  struct ceph_mdsmap *oldmap)
4339{
4340	int i, j, err;
4341	int oldstate, newstate;
4342	struct ceph_mds_session *s;
4343	unsigned long targets[DIV_ROUND_UP(CEPH_MAX_MDS, sizeof(unsigned long))] = {0};
4344
4345	dout("check_new_map new %u old %u\n",
4346	     newmap->m_epoch, oldmap->m_epoch);
4347
4348	if (newmap->m_info) {
4349		for (i = 0; i < newmap->possible_max_rank; i++) {
4350			for (j = 0; j < newmap->m_info[i].num_export_targets; j++)
4351				set_bit(newmap->m_info[i].export_targets[j], targets);
4352		}
4353	}
4354
4355	for (i = 0; i < oldmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4356		if (!mdsc->sessions[i])
4357			continue;
4358		s = mdsc->sessions[i];
4359		oldstate = ceph_mdsmap_get_state(oldmap, i);
4360		newstate = ceph_mdsmap_get_state(newmap, i);
4361
4362		dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
4363		     i, ceph_mds_state_name(oldstate),
4364		     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
4365		     ceph_mds_state_name(newstate),
4366		     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
4367		     ceph_session_state_name(s->s_state));
4368
4369		if (i >= newmap->possible_max_rank) {
4370			/* force close session for stopped mds */
4371			ceph_get_mds_session(s);
4372			__unregister_session(mdsc, s);
4373			__wake_requests(mdsc, &s->s_waiting);
4374			mutex_unlock(&mdsc->mutex);
4375
4376			mutex_lock(&s->s_mutex);
4377			cleanup_session_requests(mdsc, s);
4378			remove_session_caps(s);
4379			mutex_unlock(&s->s_mutex);
4380
4381			ceph_put_mds_session(s);
4382
4383			mutex_lock(&mdsc->mutex);
4384			kick_requests(mdsc, i);
4385			continue;
4386		}
4387
4388		if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
4389			   ceph_mdsmap_get_addr(newmap, i),
4390			   sizeof(struct ceph_entity_addr))) {
4391			/* just close it */
4392			mutex_unlock(&mdsc->mutex);
4393			mutex_lock(&s->s_mutex);
4394			mutex_lock(&mdsc->mutex);
4395			ceph_con_close(&s->s_con);
4396			mutex_unlock(&s->s_mutex);
4397			s->s_state = CEPH_MDS_SESSION_RESTARTING;
4398		} else if (oldstate == newstate) {
4399			continue;  /* nothing new with this mds */
4400		}
4401
4402		/*
4403		 * send reconnect?
4404		 */
4405		if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
4406		    newstate >= CEPH_MDS_STATE_RECONNECT) {
4407			mutex_unlock(&mdsc->mutex);
4408			clear_bit(i, targets);
4409			send_mds_reconnect(mdsc, s);
4410			mutex_lock(&mdsc->mutex);
4411		}
4412
4413		/*
4414		 * kick request on any mds that has gone active.
4415		 */
4416		if (oldstate < CEPH_MDS_STATE_ACTIVE &&
4417		    newstate >= CEPH_MDS_STATE_ACTIVE) {
4418			if (oldstate != CEPH_MDS_STATE_CREATING &&
4419			    oldstate != CEPH_MDS_STATE_STARTING)
4420				pr_info("mds%d recovery completed\n", s->s_mds);
4421			kick_requests(mdsc, i);
4422			mutex_unlock(&mdsc->mutex);
4423			mutex_lock(&s->s_mutex);
4424			mutex_lock(&mdsc->mutex);
4425			ceph_kick_flushing_caps(mdsc, s);
4426			mutex_unlock(&s->s_mutex);
4427			wake_up_session_caps(s, RECONNECT);
4428		}
4429	}
4430
4431	/*
4432	 * Only open and reconnect sessions that don't exist yet.
4433	 */
4434	for (i = 0; i < newmap->possible_max_rank; i++) {
4435		/*
4436		 * In case the import MDS is crashed just after
4437		 * the EImportStart journal is flushed, so when
4438		 * a standby MDS takes over it and is replaying
4439		 * the EImportStart journal the new MDS daemon
4440		 * will wait the client to reconnect it, but the
4441		 * client may never register/open the session yet.
4442		 *
4443		 * Will try to reconnect that MDS daemon if the
4444		 * rank number is in the export targets array and
4445		 * is the up:reconnect state.
4446		 */
4447		newstate = ceph_mdsmap_get_state(newmap, i);
4448		if (!test_bit(i, targets) || newstate != CEPH_MDS_STATE_RECONNECT)
4449			continue;
4450
4451		/*
4452		 * The session maybe registered and opened by some
4453		 * requests which were choosing random MDSes during
4454		 * the mdsc->mutex's unlock/lock gap below in rare
4455		 * case. But the related MDS daemon will just queue
4456		 * that requests and be still waiting for the client's
4457		 * reconnection request in up:reconnect state.
4458		 */
4459		s = __ceph_lookup_mds_session(mdsc, i);
4460		if (likely(!s)) {
4461			s = __open_export_target_session(mdsc, i);
4462			if (IS_ERR(s)) {
4463				err = PTR_ERR(s);
4464				pr_err("failed to open export target session, err %d\n",
4465				       err);
4466				continue;
4467			}
4468		}
4469		dout("send reconnect to export target mds.%d\n", i);
4470		mutex_unlock(&mdsc->mutex);
4471		send_mds_reconnect(mdsc, s);
4472		ceph_put_mds_session(s);
4473		mutex_lock(&mdsc->mutex);
4474	}
4475
4476	for (i = 0; i < newmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4477		s = mdsc->sessions[i];
4478		if (!s)
4479			continue;
4480		if (!ceph_mdsmap_is_laggy(newmap, i))
4481			continue;
4482		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4483		    s->s_state == CEPH_MDS_SESSION_HUNG ||
4484		    s->s_state == CEPH_MDS_SESSION_CLOSING) {
4485			dout(" connecting to export targets of laggy mds%d\n",
4486			     i);
4487			__open_export_target_sessions(mdsc, s);
4488		}
4489	}
4490}
4491
4492
4493
4494/*
4495 * leases
4496 */
4497
4498/*
4499 * caller must hold session s_mutex, dentry->d_lock
4500 */
4501void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
4502{
4503	struct ceph_dentry_info *di = ceph_dentry(dentry);
4504
4505	ceph_put_mds_session(di->lease_session);
4506	di->lease_session = NULL;
4507}
4508
4509static void handle_lease(struct ceph_mds_client *mdsc,
4510			 struct ceph_mds_session *session,
4511			 struct ceph_msg *msg)
4512{
4513	struct super_block *sb = mdsc->fsc->sb;
4514	struct inode *inode;
4515	struct dentry *parent, *dentry;
4516	struct ceph_dentry_info *di;
4517	int mds = session->s_mds;
4518	struct ceph_mds_lease *h = msg->front.iov_base;
4519	u32 seq;
4520	struct ceph_vino vino;
4521	struct qstr dname;
4522	int release = 0;
4523
4524	dout("handle_lease from mds%d\n", mds);
4525
4526	/* decode */
4527	if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
4528		goto bad;
4529	vino.ino = le64_to_cpu(h->ino);
4530	vino.snap = CEPH_NOSNAP;
4531	seq = le32_to_cpu(h->seq);
4532	dname.len = get_unaligned_le32(h + 1);
4533	if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
4534		goto bad;
4535	dname.name = (void *)(h + 1) + sizeof(u32);
4536
4537	/* lookup inode */
4538	inode = ceph_find_inode(sb, vino);
4539	dout("handle_lease %s, ino %llx %p %.*s\n",
4540	     ceph_lease_op_name(h->action), vino.ino, inode,
4541	     dname.len, dname.name);
4542
4543	mutex_lock(&session->s_mutex);
4544	inc_session_sequence(session);
4545
4546	if (!inode) {
4547		dout("handle_lease no inode %llx\n", vino.ino);
4548		goto release;
4549	}
4550
4551	/* dentry */
4552	parent = d_find_alias(inode);
4553	if (!parent) {
4554		dout("no parent dentry on inode %p\n", inode);
4555		WARN_ON(1);
4556		goto release;  /* hrm... */
4557	}
4558	dname.hash = full_name_hash(parent, dname.name, dname.len);
4559	dentry = d_lookup(parent, &dname);
4560	dput(parent);
4561	if (!dentry)
4562		goto release;
4563
4564	spin_lock(&dentry->d_lock);
4565	di = ceph_dentry(dentry);
4566	switch (h->action) {
4567	case CEPH_MDS_LEASE_REVOKE:
4568		if (di->lease_session == session) {
4569			if (ceph_seq_cmp(di->lease_seq, seq) > 0)
4570				h->seq = cpu_to_le32(di->lease_seq);
4571			__ceph_mdsc_drop_dentry_lease(dentry);
4572		}
4573		release = 1;
4574		break;
4575
4576	case CEPH_MDS_LEASE_RENEW:
4577		if (di->lease_session == session &&
4578		    di->lease_gen == atomic_read(&session->s_cap_gen) &&
4579		    di->lease_renew_from &&
4580		    di->lease_renew_after == 0) {
4581			unsigned long duration =
4582				msecs_to_jiffies(le32_to_cpu(h->duration_ms));
4583
4584			di->lease_seq = seq;
4585			di->time = di->lease_renew_from + duration;
4586			di->lease_renew_after = di->lease_renew_from +
4587				(duration >> 1);
4588			di->lease_renew_from = 0;
4589		}
4590		break;
4591	}
4592	spin_unlock(&dentry->d_lock);
4593	dput(dentry);
4594
4595	if (!release)
4596		goto out;
4597
4598release:
4599	/* let's just reuse the same message */
4600	h->action = CEPH_MDS_LEASE_REVOKE_ACK;
4601	ceph_msg_get(msg);
4602	ceph_con_send(&session->s_con, msg);
4603
4604out:
4605	mutex_unlock(&session->s_mutex);
4606	iput(inode);
4607	return;
4608
4609bad:
4610	pr_err("corrupt lease message\n");
4611	ceph_msg_dump(msg);
4612}
4613
4614void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
4615			      struct dentry *dentry, char action,
4616			      u32 seq)
4617{
4618	struct ceph_msg *msg;
4619	struct ceph_mds_lease *lease;
4620	struct inode *dir;
4621	int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
4622
4623	dout("lease_send_msg identry %p %s to mds%d\n",
4624	     dentry, ceph_lease_op_name(action), session->s_mds);
4625
4626	msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
4627	if (!msg)
4628		return;
4629	lease = msg->front.iov_base;
4630	lease->action = action;
4631	lease->seq = cpu_to_le32(seq);
4632
4633	spin_lock(&dentry->d_lock);
4634	dir = d_inode(dentry->d_parent);
4635	lease->ino = cpu_to_le64(ceph_ino(dir));
4636	lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4637
4638	put_unaligned_le32(dentry->d_name.len, lease + 1);
4639	memcpy((void *)(lease + 1) + 4,
4640	       dentry->d_name.name, dentry->d_name.len);
4641	spin_unlock(&dentry->d_lock);
 
 
 
 
 
 
4642
4643	ceph_con_send(&session->s_con, msg);
4644}
4645
4646/*
4647 * lock unlock the session, to wait ongoing session activities
4648 */
4649static void lock_unlock_session(struct ceph_mds_session *s)
4650{
4651	mutex_lock(&s->s_mutex);
4652	mutex_unlock(&s->s_mutex);
 
 
 
 
 
 
 
 
 
 
 
 
4653}
4654
4655static void maybe_recover_session(struct ceph_mds_client *mdsc)
4656{
4657	struct ceph_fs_client *fsc = mdsc->fsc;
4658
4659	if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4660		return;
4661
4662	if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4663		return;
4664
4665	if (!READ_ONCE(fsc->blocklisted))
4666		return;
4667
4668	pr_info("auto reconnect after blocklisted\n");
4669	ceph_force_reconnect(fsc->sb);
4670}
4671
4672bool check_session_state(struct ceph_mds_session *s)
4673{
4674	switch (s->s_state) {
4675	case CEPH_MDS_SESSION_OPEN:
4676		if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4677			s->s_state = CEPH_MDS_SESSION_HUNG;
4678			pr_info("mds%d hung\n", s->s_mds);
4679		}
4680		break;
4681	case CEPH_MDS_SESSION_CLOSING:
 
 
 
4682	case CEPH_MDS_SESSION_NEW:
4683	case CEPH_MDS_SESSION_RESTARTING:
4684	case CEPH_MDS_SESSION_CLOSED:
4685	case CEPH_MDS_SESSION_REJECTED:
4686		return false;
4687	}
4688
4689	return true;
4690}
4691
4692/*
4693 * If the sequence is incremented while we're waiting on a REQUEST_CLOSE reply,
4694 * then we need to retransmit that request.
4695 */
4696void inc_session_sequence(struct ceph_mds_session *s)
4697{
4698	lockdep_assert_held(&s->s_mutex);
4699
4700	s->s_seq++;
4701
4702	if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4703		int ret;
4704
4705		dout("resending session close request for mds%d\n", s->s_mds);
4706		ret = request_close_session(s);
4707		if (ret < 0)
4708			pr_err("unable to close session to mds%d: %d\n",
4709			       s->s_mds, ret);
4710	}
4711}
4712
4713/*
4714 * delayed work -- periodically trim expired leases, renew caps with mds.  If
4715 * the @delay parameter is set to 0 or if it's more than 5 secs, the default
4716 * workqueue delay value of 5 secs will be used.
4717 */
4718static void schedule_delayed(struct ceph_mds_client *mdsc, unsigned long delay)
4719{
4720	unsigned long max_delay = HZ * 5;
4721
4722	/* 5 secs default delay */
4723	if (!delay || (delay > max_delay))
4724		delay = max_delay;
4725	schedule_delayed_work(&mdsc->delayed_work,
4726			      round_jiffies_relative(delay));
4727}
4728
4729static void delayed_work(struct work_struct *work)
4730{
4731	struct ceph_mds_client *mdsc =
4732		container_of(work, struct ceph_mds_client, delayed_work.work);
4733	unsigned long delay;
4734	int renew_interval;
4735	int renew_caps;
4736	int i;
4737
4738	dout("mdsc delayed_work\n");
4739
4740	if (mdsc->stopping)
4741		return;
4742
4743	mutex_lock(&mdsc->mutex);
4744	renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4745	renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4746				   mdsc->last_renew_caps);
4747	if (renew_caps)
4748		mdsc->last_renew_caps = jiffies;
4749
4750	for (i = 0; i < mdsc->max_sessions; i++) {
4751		struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4752		if (!s)
4753			continue;
4754
4755		if (!check_session_state(s)) {
4756			ceph_put_mds_session(s);
4757			continue;
4758		}
4759		mutex_unlock(&mdsc->mutex);
4760
4761		mutex_lock(&s->s_mutex);
4762		if (renew_caps)
4763			send_renew_caps(mdsc, s);
4764		else
4765			ceph_con_keepalive(&s->s_con);
4766		if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4767		    s->s_state == CEPH_MDS_SESSION_HUNG)
4768			ceph_send_cap_releases(mdsc, s);
4769		mutex_unlock(&s->s_mutex);
4770		ceph_put_mds_session(s);
4771
4772		mutex_lock(&mdsc->mutex);
4773	}
4774	mutex_unlock(&mdsc->mutex);
4775
4776	delay = ceph_check_delayed_caps(mdsc);
4777
4778	ceph_queue_cap_reclaim_work(mdsc);
4779
4780	ceph_trim_snapid_map(mdsc);
4781
4782	maybe_recover_session(mdsc);
4783
4784	schedule_delayed(mdsc, delay);
4785}
4786
4787int ceph_mdsc_init(struct ceph_fs_client *fsc)
4788
4789{
4790	struct ceph_mds_client *mdsc;
4791	int err;
4792
4793	mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4794	if (!mdsc)
4795		return -ENOMEM;
4796	mdsc->fsc = fsc;
4797	mutex_init(&mdsc->mutex);
4798	mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4799	if (!mdsc->mdsmap) {
4800		err = -ENOMEM;
4801		goto err_mdsc;
4802	}
4803
4804	init_completion(&mdsc->safe_umount_waiters);
4805	init_waitqueue_head(&mdsc->session_close_wq);
4806	INIT_LIST_HEAD(&mdsc->waiting_for_map);
 
 
 
 
 
4807	mdsc->quotarealms_inodes = RB_ROOT;
4808	mutex_init(&mdsc->quotarealms_inodes_mutex);
 
4809	init_rwsem(&mdsc->snap_rwsem);
4810	mdsc->snap_realms = RB_ROOT;
4811	INIT_LIST_HEAD(&mdsc->snap_empty);
 
4812	spin_lock_init(&mdsc->snap_empty_lock);
 
 
4813	mdsc->request_tree = RB_ROOT;
4814	INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4815	mdsc->last_renew_caps = jiffies;
4816	INIT_LIST_HEAD(&mdsc->cap_delay_list);
4817	INIT_LIST_HEAD(&mdsc->cap_wait_list);
4818	spin_lock_init(&mdsc->cap_delay_lock);
4819	INIT_LIST_HEAD(&mdsc->snap_flush_list);
4820	spin_lock_init(&mdsc->snap_flush_lock);
4821	mdsc->last_cap_flush_tid = 1;
4822	INIT_LIST_HEAD(&mdsc->cap_flush_list);
4823	INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
 
4824	spin_lock_init(&mdsc->cap_dirty_lock);
4825	init_waitqueue_head(&mdsc->cap_flushing_wq);
4826	INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
 
4827	err = ceph_metric_init(&mdsc->metric);
4828	if (err)
4829		goto err_mdsmap;
4830
4831	spin_lock_init(&mdsc->dentry_list_lock);
4832	INIT_LIST_HEAD(&mdsc->dentry_leases);
4833	INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4834
4835	ceph_caps_init(mdsc);
4836	ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4837
4838	spin_lock_init(&mdsc->snapid_map_lock);
4839	mdsc->snapid_map_tree = RB_ROOT;
4840	INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4841
4842	init_rwsem(&mdsc->pool_perm_rwsem);
4843	mdsc->pool_perm_tree = RB_ROOT;
4844
4845	strscpy(mdsc->nodename, utsname()->nodename,
4846		sizeof(mdsc->nodename));
4847
4848	fsc->mdsc = mdsc;
4849	return 0;
4850
4851err_mdsmap:
4852	kfree(mdsc->mdsmap);
4853err_mdsc:
4854	kfree(mdsc);
4855	return err;
4856}
4857
4858/*
4859 * Wait for safe replies on open mds requests.  If we time out, drop
4860 * all requests from the tree to avoid dangling dentry refs.
4861 */
4862static void wait_requests(struct ceph_mds_client *mdsc)
4863{
4864	struct ceph_options *opts = mdsc->fsc->client->options;
4865	struct ceph_mds_request *req;
4866
4867	mutex_lock(&mdsc->mutex);
4868	if (__get_oldest_req(mdsc)) {
4869		mutex_unlock(&mdsc->mutex);
4870
4871		dout("wait_requests waiting for requests\n");
4872		wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4873				    ceph_timeout_jiffies(opts->mount_timeout));
4874
4875		/* tear down remaining requests */
4876		mutex_lock(&mdsc->mutex);
4877		while ((req = __get_oldest_req(mdsc))) {
4878			dout("wait_requests timed out on tid %llu\n",
4879			     req->r_tid);
4880			list_del_init(&req->r_wait);
4881			__unregister_request(mdsc, req);
4882		}
4883	}
4884	mutex_unlock(&mdsc->mutex);
4885	dout("wait_requests done\n");
4886}
4887
4888void send_flush_mdlog(struct ceph_mds_session *s)
4889{
4890	struct ceph_msg *msg;
4891
4892	/*
4893	 * Pre-luminous MDS crashes when it sees an unknown session request
4894	 */
4895	if (!CEPH_HAVE_FEATURE(s->s_con.peer_features, SERVER_LUMINOUS))
4896		return;
4897
4898	mutex_lock(&s->s_mutex);
4899	dout("request mdlog flush to mds%d (%s)s seq %lld\n", s->s_mds,
4900	     ceph_session_state_name(s->s_state), s->s_seq);
4901	msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_FLUSH_MDLOG,
4902				      s->s_seq);
4903	if (!msg) {
4904		pr_err("failed to request mdlog flush to mds%d (%s) seq %lld\n",
4905		       s->s_mds, ceph_session_state_name(s->s_state), s->s_seq);
4906	} else {
4907		ceph_con_send(&s->s_con, msg);
4908	}
4909	mutex_unlock(&s->s_mutex);
4910}
4911
4912/*
4913 * called before mount is ro, and before dentries are torn down.
4914 * (hmm, does this still race with new lookups?)
4915 */
4916void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4917{
4918	dout("pre_umount\n");
4919	mdsc->stopping = 1;
4920
4921	ceph_mdsc_iterate_sessions(mdsc, send_flush_mdlog, true);
4922	ceph_mdsc_iterate_sessions(mdsc, lock_unlock_session, false);
4923	ceph_flush_dirty_caps(mdsc);
4924	wait_requests(mdsc);
4925
4926	/*
4927	 * wait for reply handlers to drop their request refs and
4928	 * their inode/dcache refs
4929	 */
4930	ceph_msgr_flush();
4931
4932	ceph_cleanup_quotarealms_inodes(mdsc);
4933}
4934
4935/*
4936 * flush the mdlog and wait for all write mds requests to flush.
4937 */
4938static void flush_mdlog_and_wait_mdsc_unsafe_requests(struct ceph_mds_client *mdsc,
4939						 u64 want_tid)
4940{
4941	struct ceph_mds_request *req = NULL, *nextreq;
4942	struct ceph_mds_session *last_session = NULL;
4943	struct rb_node *n;
4944
4945	mutex_lock(&mdsc->mutex);
4946	dout("%s want %lld\n", __func__, want_tid);
4947restart:
4948	req = __get_oldest_req(mdsc);
4949	while (req && req->r_tid <= want_tid) {
4950		/* find next request */
4951		n = rb_next(&req->r_node);
4952		if (n)
4953			nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4954		else
4955			nextreq = NULL;
4956		if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4957		    (req->r_op & CEPH_MDS_OP_WRITE)) {
4958			struct ceph_mds_session *s = req->r_session;
4959
4960			if (!s) {
4961				req = nextreq;
4962				continue;
4963			}
4964
4965			/* write op */
4966			ceph_mdsc_get_request(req);
4967			if (nextreq)
4968				ceph_mdsc_get_request(nextreq);
4969			s = ceph_get_mds_session(s);
4970			mutex_unlock(&mdsc->mutex);
4971
4972			/* send flush mdlog request to MDS */
4973			if (last_session != s) {
4974				send_flush_mdlog(s);
4975				ceph_put_mds_session(last_session);
4976				last_session = s;
4977			} else {
4978				ceph_put_mds_session(s);
4979			}
4980			dout("%s wait on %llu (want %llu)\n", __func__,
4981			     req->r_tid, want_tid);
4982			wait_for_completion(&req->r_safe_completion);
4983
4984			mutex_lock(&mdsc->mutex);
4985			ceph_mdsc_put_request(req);
4986			if (!nextreq)
4987				break;  /* next dne before, so we're done! */
4988			if (RB_EMPTY_NODE(&nextreq->r_node)) {
4989				/* next request was removed from tree */
4990				ceph_mdsc_put_request(nextreq);
4991				goto restart;
4992			}
4993			ceph_mdsc_put_request(nextreq);  /* won't go away */
4994		}
4995		req = nextreq;
4996	}
4997	mutex_unlock(&mdsc->mutex);
4998	ceph_put_mds_session(last_session);
4999	dout("%s done\n", __func__);
5000}
5001
5002void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
5003{
5004	u64 want_tid, want_flush;
5005
5006	if (READ_ONCE(mdsc->fsc->mount_state) >= CEPH_MOUNT_SHUTDOWN)
5007		return;
5008
5009	dout("sync\n");
5010	mutex_lock(&mdsc->mutex);
5011	want_tid = mdsc->last_tid;
5012	mutex_unlock(&mdsc->mutex);
5013
5014	ceph_flush_dirty_caps(mdsc);
5015	spin_lock(&mdsc->cap_dirty_lock);
5016	want_flush = mdsc->last_cap_flush_tid;
5017	if (!list_empty(&mdsc->cap_flush_list)) {
5018		struct ceph_cap_flush *cf =
5019			list_last_entry(&mdsc->cap_flush_list,
5020					struct ceph_cap_flush, g_list);
5021		cf->wake = true;
5022	}
5023	spin_unlock(&mdsc->cap_dirty_lock);
5024
5025	dout("sync want tid %lld flush_seq %lld\n",
5026	     want_tid, want_flush);
5027
5028	flush_mdlog_and_wait_mdsc_unsafe_requests(mdsc, want_tid);
5029	wait_caps_flush(mdsc, want_flush);
5030}
5031
5032/*
5033 * true if all sessions are closed, or we force unmount
5034 */
5035static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
5036{
5037	if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
5038		return true;
5039	return atomic_read(&mdsc->num_sessions) <= skipped;
5040}
5041
5042/*
5043 * called after sb is ro or when metadata corrupted.
5044 */
5045void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
5046{
5047	struct ceph_options *opts = mdsc->fsc->client->options;
5048	struct ceph_mds_session *session;
5049	int i;
5050	int skipped = 0;
5051
5052	dout("close_sessions\n");
5053
5054	/* close sessions */
5055	mutex_lock(&mdsc->mutex);
5056	for (i = 0; i < mdsc->max_sessions; i++) {
5057		session = __ceph_lookup_mds_session(mdsc, i);
5058		if (!session)
5059			continue;
5060		mutex_unlock(&mdsc->mutex);
5061		mutex_lock(&session->s_mutex);
5062		if (__close_session(mdsc, session) <= 0)
5063			skipped++;
5064		mutex_unlock(&session->s_mutex);
5065		ceph_put_mds_session(session);
5066		mutex_lock(&mdsc->mutex);
5067	}
5068	mutex_unlock(&mdsc->mutex);
5069
5070	dout("waiting for sessions to close\n");
5071	wait_event_timeout(mdsc->session_close_wq,
5072			   done_closing_sessions(mdsc, skipped),
5073			   ceph_timeout_jiffies(opts->mount_timeout));
5074
5075	/* tear down remaining sessions */
5076	mutex_lock(&mdsc->mutex);
5077	for (i = 0; i < mdsc->max_sessions; i++) {
5078		if (mdsc->sessions[i]) {
5079			session = ceph_get_mds_session(mdsc->sessions[i]);
5080			__unregister_session(mdsc, session);
5081			mutex_unlock(&mdsc->mutex);
5082			mutex_lock(&session->s_mutex);
5083			remove_session_caps(session);
5084			mutex_unlock(&session->s_mutex);
5085			ceph_put_mds_session(session);
5086			mutex_lock(&mdsc->mutex);
5087		}
5088	}
5089	WARN_ON(!list_empty(&mdsc->cap_delay_list));
5090	mutex_unlock(&mdsc->mutex);
5091
5092	ceph_cleanup_snapid_map(mdsc);
5093	ceph_cleanup_global_and_empty_realms(mdsc);
5094
5095	cancel_work_sync(&mdsc->cap_reclaim_work);
5096	cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
5097
5098	dout("stopped\n");
5099}
5100
5101void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
5102{
5103	struct ceph_mds_session *session;
5104	int mds;
5105
5106	dout("force umount\n");
5107
5108	mutex_lock(&mdsc->mutex);
5109	for (mds = 0; mds < mdsc->max_sessions; mds++) {
5110		session = __ceph_lookup_mds_session(mdsc, mds);
5111		if (!session)
5112			continue;
5113
5114		if (session->s_state == CEPH_MDS_SESSION_REJECTED)
5115			__unregister_session(mdsc, session);
5116		__wake_requests(mdsc, &session->s_waiting);
5117		mutex_unlock(&mdsc->mutex);
5118
5119		mutex_lock(&session->s_mutex);
5120		__close_session(mdsc, session);
5121		if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
5122			cleanup_session_requests(mdsc, session);
5123			remove_session_caps(session);
5124		}
5125		mutex_unlock(&session->s_mutex);
5126		ceph_put_mds_session(session);
5127
5128		mutex_lock(&mdsc->mutex);
5129		kick_requests(mdsc, mds);
5130	}
5131	__wake_requests(mdsc, &mdsc->waiting_for_map);
5132	mutex_unlock(&mdsc->mutex);
5133}
5134
5135static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
5136{
5137	dout("stop\n");
5138	/*
5139	 * Make sure the delayed work stopped before releasing
5140	 * the resources.
5141	 *
5142	 * Because the cancel_delayed_work_sync() will only
5143	 * guarantee that the work finishes executing. But the
5144	 * delayed work will re-arm itself again after that.
5145	 */
5146	flush_delayed_work(&mdsc->delayed_work);
5147
5148	if (mdsc->mdsmap)
5149		ceph_mdsmap_destroy(mdsc->mdsmap);
5150	kfree(mdsc->sessions);
5151	ceph_caps_finalize(mdsc);
5152	ceph_pool_perm_destroy(mdsc);
5153}
5154
5155void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
5156{
5157	struct ceph_mds_client *mdsc = fsc->mdsc;
5158	dout("mdsc_destroy %p\n", mdsc);
5159
5160	if (!mdsc)
5161		return;
5162
5163	/* flush out any connection work with references to us */
5164	ceph_msgr_flush();
5165
5166	ceph_mdsc_stop(mdsc);
5167
5168	ceph_metric_destroy(&mdsc->metric);
5169
5170	fsc->mdsc = NULL;
5171	kfree(mdsc);
5172	dout("mdsc_destroy %p done\n", mdsc);
5173}
5174
5175void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
5176{
5177	struct ceph_fs_client *fsc = mdsc->fsc;
5178	const char *mds_namespace = fsc->mount_options->mds_namespace;
5179	void *p = msg->front.iov_base;
5180	void *end = p + msg->front.iov_len;
5181	u32 epoch;
5182	u32 num_fs;
5183	u32 mount_fscid = (u32)-1;
5184	int err = -EINVAL;
5185
5186	ceph_decode_need(&p, end, sizeof(u32), bad);
5187	epoch = ceph_decode_32(&p);
5188
5189	dout("handle_fsmap epoch %u\n", epoch);
5190
5191	/* struct_v, struct_cv, map_len, epoch, legacy_client_fscid */
5192	ceph_decode_skip_n(&p, end, 2 + sizeof(u32) * 3, bad);
5193
5194	ceph_decode_32_safe(&p, end, num_fs, bad);
5195	while (num_fs-- > 0) {
5196		void *info_p, *info_end;
5197		u32 info_len;
5198		u32 fscid, namelen;
5199
5200		ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
5201		p += 2;		// info_v, info_cv
5202		info_len = ceph_decode_32(&p);
5203		ceph_decode_need(&p, end, info_len, bad);
5204		info_p = p;
5205		info_end = p + info_len;
5206		p = info_end;
5207
5208		ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
5209		fscid = ceph_decode_32(&info_p);
5210		namelen = ceph_decode_32(&info_p);
5211		ceph_decode_need(&info_p, info_end, namelen, bad);
5212
5213		if (mds_namespace &&
5214		    strlen(mds_namespace) == namelen &&
5215		    !strncmp(mds_namespace, (char *)info_p, namelen)) {
5216			mount_fscid = fscid;
5217			break;
5218		}
5219	}
5220
5221	ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
5222	if (mount_fscid != (u32)-1) {
5223		fsc->client->monc.fs_cluster_id = mount_fscid;
5224		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
5225				   0, true);
5226		ceph_monc_renew_subs(&fsc->client->monc);
5227	} else {
5228		err = -ENOENT;
5229		goto err_out;
5230	}
5231	return;
5232
5233bad:
5234	pr_err("error decoding fsmap %d. Shutting down mount.\n", err);
5235	ceph_umount_begin(mdsc->fsc->sb);
5236err_out:
5237	mutex_lock(&mdsc->mutex);
5238	mdsc->mdsmap_err = err;
5239	__wake_requests(mdsc, &mdsc->waiting_for_map);
5240	mutex_unlock(&mdsc->mutex);
5241}
5242
5243/*
5244 * handle mds map update.
5245 */
5246void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
5247{
5248	u32 epoch;
5249	u32 maplen;
5250	void *p = msg->front.iov_base;
5251	void *end = p + msg->front.iov_len;
5252	struct ceph_mdsmap *newmap, *oldmap;
5253	struct ceph_fsid fsid;
5254	int err = -EINVAL;
5255
5256	ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
5257	ceph_decode_copy(&p, &fsid, sizeof(fsid));
5258	if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
5259		return;
5260	epoch = ceph_decode_32(&p);
5261	maplen = ceph_decode_32(&p);
5262	dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
5263
5264	/* do we need it? */
5265	mutex_lock(&mdsc->mutex);
5266	if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
5267		dout("handle_map epoch %u <= our %u\n",
5268		     epoch, mdsc->mdsmap->m_epoch);
5269		mutex_unlock(&mdsc->mutex);
5270		return;
5271	}
5272
5273	newmap = ceph_mdsmap_decode(&p, end, ceph_msgr2(mdsc->fsc->client));
5274	if (IS_ERR(newmap)) {
5275		err = PTR_ERR(newmap);
5276		goto bad_unlock;
5277	}
5278
5279	/* swap into place */
5280	if (mdsc->mdsmap) {
5281		oldmap = mdsc->mdsmap;
5282		mdsc->mdsmap = newmap;
5283		check_new_map(mdsc, newmap, oldmap);
5284		ceph_mdsmap_destroy(oldmap);
5285	} else {
5286		mdsc->mdsmap = newmap;  /* first mds map */
5287	}
5288	mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
5289					MAX_LFS_FILESIZE);
5290
5291	__wake_requests(mdsc, &mdsc->waiting_for_map);
5292	ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
5293			  mdsc->mdsmap->m_epoch);
5294
5295	mutex_unlock(&mdsc->mutex);
5296	schedule_delayed(mdsc, 0);
5297	return;
5298
5299bad_unlock:
5300	mutex_unlock(&mdsc->mutex);
5301bad:
5302	pr_err("error decoding mdsmap %d. Shutting down mount.\n", err);
5303	ceph_umount_begin(mdsc->fsc->sb);
5304	return;
5305}
5306
5307static struct ceph_connection *mds_get_con(struct ceph_connection *con)
5308{
5309	struct ceph_mds_session *s = con->private;
5310
5311	if (ceph_get_mds_session(s))
5312		return con;
5313	return NULL;
5314}
5315
5316static void mds_put_con(struct ceph_connection *con)
5317{
5318	struct ceph_mds_session *s = con->private;
5319
5320	ceph_put_mds_session(s);
5321}
5322
5323/*
5324 * if the client is unresponsive for long enough, the mds will kill
5325 * the session entirely.
5326 */
5327static void mds_peer_reset(struct ceph_connection *con)
5328{
5329	struct ceph_mds_session *s = con->private;
5330	struct ceph_mds_client *mdsc = s->s_mdsc;
5331
5332	pr_warn("mds%d closed our session\n", s->s_mds);
5333	if (READ_ONCE(mdsc->fsc->mount_state) != CEPH_MOUNT_FENCE_IO)
5334		send_mds_reconnect(mdsc, s);
5335}
5336
5337static void mds_dispatch(struct ceph_connection *con, struct ceph_msg *msg)
5338{
5339	struct ceph_mds_session *s = con->private;
5340	struct ceph_mds_client *mdsc = s->s_mdsc;
5341	int type = le16_to_cpu(msg->hdr.type);
5342
5343	mutex_lock(&mdsc->mutex);
5344	if (__verify_registered_session(mdsc, s) < 0) {
5345		mutex_unlock(&mdsc->mutex);
5346		goto out;
5347	}
5348	mutex_unlock(&mdsc->mutex);
5349
5350	switch (type) {
5351	case CEPH_MSG_MDS_MAP:
5352		ceph_mdsc_handle_mdsmap(mdsc, msg);
5353		break;
5354	case CEPH_MSG_FS_MAP_USER:
5355		ceph_mdsc_handle_fsmap(mdsc, msg);
5356		break;
5357	case CEPH_MSG_CLIENT_SESSION:
5358		handle_session(s, msg);
5359		break;
5360	case CEPH_MSG_CLIENT_REPLY:
5361		handle_reply(s, msg);
5362		break;
5363	case CEPH_MSG_CLIENT_REQUEST_FORWARD:
5364		handle_forward(mdsc, s, msg);
5365		break;
5366	case CEPH_MSG_CLIENT_CAPS:
5367		ceph_handle_caps(s, msg);
5368		break;
5369	case CEPH_MSG_CLIENT_SNAP:
5370		ceph_handle_snap(mdsc, s, msg);
5371		break;
5372	case CEPH_MSG_CLIENT_LEASE:
5373		handle_lease(mdsc, s, msg);
5374		break;
5375	case CEPH_MSG_CLIENT_QUOTA:
5376		ceph_handle_quota(mdsc, s, msg);
5377		break;
5378
5379	default:
5380		pr_err("received unknown message type %d %s\n", type,
5381		       ceph_msg_type_name(type));
5382	}
5383out:
5384	ceph_msg_put(msg);
5385}
5386
5387/*
5388 * authentication
5389 */
5390
5391/*
5392 * Note: returned pointer is the address of a structure that's
5393 * managed separately.  Caller must *not* attempt to free it.
5394 */
5395static struct ceph_auth_handshake *
5396mds_get_authorizer(struct ceph_connection *con, int *proto, int force_new)
5397{
5398	struct ceph_mds_session *s = con->private;
5399	struct ceph_mds_client *mdsc = s->s_mdsc;
5400	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5401	struct ceph_auth_handshake *auth = &s->s_auth;
5402	int ret;
5403
5404	ret = __ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_MDS,
5405					 force_new, proto, NULL, NULL);
5406	if (ret)
5407		return ERR_PTR(ret);
5408
5409	return auth;
5410}
5411
5412static int mds_add_authorizer_challenge(struct ceph_connection *con,
5413				    void *challenge_buf, int challenge_buf_len)
5414{
5415	struct ceph_mds_session *s = con->private;
5416	struct ceph_mds_client *mdsc = s->s_mdsc;
5417	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5418
5419	return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
5420					    challenge_buf, challenge_buf_len);
5421}
5422
5423static int mds_verify_authorizer_reply(struct ceph_connection *con)
5424{
5425	struct ceph_mds_session *s = con->private;
5426	struct ceph_mds_client *mdsc = s->s_mdsc;
5427	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5428	struct ceph_auth_handshake *auth = &s->s_auth;
5429
5430	return ceph_auth_verify_authorizer_reply(ac, auth->authorizer,
5431		auth->authorizer_reply_buf, auth->authorizer_reply_buf_len,
5432		NULL, NULL, NULL, NULL);
5433}
5434
5435static int mds_invalidate_authorizer(struct ceph_connection *con)
5436{
5437	struct ceph_mds_session *s = con->private;
5438	struct ceph_mds_client *mdsc = s->s_mdsc;
5439	struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5440
5441	ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
5442
5443	return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
5444}
5445
5446static int mds_get_auth_request(struct ceph_connection *con,
5447				void *buf, int *buf_len,
5448				void **authorizer, int *authorizer_len)
5449{
5450	struct ceph_mds_session *s = con->private;
5451	struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5452	struct ceph_auth_handshake *auth = &s->s_auth;
5453	int ret;
5454
5455	ret = ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_MDS,
5456				       buf, buf_len);
5457	if (ret)
5458		return ret;
5459
5460	*authorizer = auth->authorizer_buf;
5461	*authorizer_len = auth->authorizer_buf_len;
5462	return 0;
5463}
5464
5465static int mds_handle_auth_reply_more(struct ceph_connection *con,
5466				      void *reply, int reply_len,
5467				      void *buf, int *buf_len,
5468				      void **authorizer, int *authorizer_len)
5469{
5470	struct ceph_mds_session *s = con->private;
5471	struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5472	struct ceph_auth_handshake *auth = &s->s_auth;
5473	int ret;
5474
5475	ret = ceph_auth_handle_svc_reply_more(ac, auth, reply, reply_len,
5476					      buf, buf_len);
5477	if (ret)
5478		return ret;
5479
5480	*authorizer = auth->authorizer_buf;
5481	*authorizer_len = auth->authorizer_buf_len;
5482	return 0;
5483}
5484
5485static int mds_handle_auth_done(struct ceph_connection *con,
5486				u64 global_id, void *reply, int reply_len,
5487				u8 *session_key, int *session_key_len,
5488				u8 *con_secret, int *con_secret_len)
5489{
5490	struct ceph_mds_session *s = con->private;
5491	struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5492	struct ceph_auth_handshake *auth = &s->s_auth;
5493
5494	return ceph_auth_handle_svc_reply_done(ac, auth, reply, reply_len,
5495					       session_key, session_key_len,
5496					       con_secret, con_secret_len);
5497}
5498
5499static int mds_handle_auth_bad_method(struct ceph_connection *con,
5500				      int used_proto, int result,
5501				      const int *allowed_protos, int proto_cnt,
5502				      const int *allowed_modes, int mode_cnt)
5503{
5504	struct ceph_mds_session *s = con->private;
5505	struct ceph_mon_client *monc = &s->s_mdsc->fsc->client->monc;
5506	int ret;
5507
5508	if (ceph_auth_handle_bad_authorizer(monc->auth, CEPH_ENTITY_TYPE_MDS,
5509					    used_proto, result,
5510					    allowed_protos, proto_cnt,
5511					    allowed_modes, mode_cnt)) {
5512		ret = ceph_monc_validate_auth(monc);
5513		if (ret)
5514			return ret;
5515	}
5516
5517	return -EACCES;
5518}
5519
5520static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
5521				struct ceph_msg_header *hdr, int *skip)
5522{
5523	struct ceph_msg *msg;
5524	int type = (int) le16_to_cpu(hdr->type);
5525	int front_len = (int) le32_to_cpu(hdr->front_len);
5526
5527	if (con->in_msg)
5528		return con->in_msg;
5529
5530	*skip = 0;
5531	msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
5532	if (!msg) {
5533		pr_err("unable to allocate msg type %d len %d\n",
5534		       type, front_len);
5535		return NULL;
5536	}
5537
5538	return msg;
5539}
5540
5541static int mds_sign_message(struct ceph_msg *msg)
5542{
5543       struct ceph_mds_session *s = msg->con->private;
5544       struct ceph_auth_handshake *auth = &s->s_auth;
5545
5546       return ceph_auth_sign_message(auth, msg);
5547}
5548
5549static int mds_check_message_signature(struct ceph_msg *msg)
5550{
5551       struct ceph_mds_session *s = msg->con->private;
5552       struct ceph_auth_handshake *auth = &s->s_auth;
5553
5554       return ceph_auth_check_message_signature(auth, msg);
5555}
5556
5557static const struct ceph_connection_operations mds_con_ops = {
5558	.get = mds_get_con,
5559	.put = mds_put_con,
5560	.alloc_msg = mds_alloc_msg,
5561	.dispatch = mds_dispatch,
5562	.peer_reset = mds_peer_reset,
5563	.get_authorizer = mds_get_authorizer,
5564	.add_authorizer_challenge = mds_add_authorizer_challenge,
5565	.verify_authorizer_reply = mds_verify_authorizer_reply,
5566	.invalidate_authorizer = mds_invalidate_authorizer,
5567	.sign_message = mds_sign_message,
5568	.check_message_signature = mds_check_message_signature,
5569	.get_auth_request = mds_get_auth_request,
5570	.handle_auth_reply_more = mds_handle_auth_reply_more,
5571	.handle_auth_done = mds_handle_auth_done,
5572	.handle_auth_bad_method = mds_handle_auth_bad_method,
5573};
5574
5575/* eof */