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v3.15
   1#include <linux/ceph/ceph_debug.h>
   2
   3#include <linux/fs.h>
   4#include <linux/kernel.h>
   5#include <linux/sched.h>
   6#include <linux/slab.h>
   7#include <linux/vmalloc.h>
   8#include <linux/wait.h>
   9#include <linux/writeback.h>
  10
  11#include "super.h"
  12#include "mds_client.h"
  13#include "cache.h"
  14#include <linux/ceph/decode.h>
  15#include <linux/ceph/messenger.h>
  16
  17/*
  18 * Capability management
  19 *
  20 * The Ceph metadata servers control client access to inode metadata
  21 * and file data by issuing capabilities, granting clients permission
  22 * to read and/or write both inode field and file data to OSDs
  23 * (storage nodes).  Each capability consists of a set of bits
  24 * indicating which operations are allowed.
  25 *
  26 * If the client holds a *_SHARED cap, the client has a coherent value
  27 * that can be safely read from the cached inode.
  28 *
  29 * In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the
  30 * client is allowed to change inode attributes (e.g., file size,
  31 * mtime), note its dirty state in the ceph_cap, and asynchronously
  32 * flush that metadata change to the MDS.
  33 *
  34 * In the event of a conflicting operation (perhaps by another
  35 * client), the MDS will revoke the conflicting client capabilities.
  36 *
  37 * In order for a client to cache an inode, it must hold a capability
  38 * with at least one MDS server.  When inodes are released, release
  39 * notifications are batched and periodically sent en masse to the MDS
  40 * cluster to release server state.
  41 */
  42
  43
  44/*
  45 * Generate readable cap strings for debugging output.
  46 */
  47#define MAX_CAP_STR 20
  48static char cap_str[MAX_CAP_STR][40];
  49static DEFINE_SPINLOCK(cap_str_lock);
  50static int last_cap_str;
  51
  52static char *gcap_string(char *s, int c)
  53{
  54	if (c & CEPH_CAP_GSHARED)
  55		*s++ = 's';
  56	if (c & CEPH_CAP_GEXCL)
  57		*s++ = 'x';
  58	if (c & CEPH_CAP_GCACHE)
  59		*s++ = 'c';
  60	if (c & CEPH_CAP_GRD)
  61		*s++ = 'r';
  62	if (c & CEPH_CAP_GWR)
  63		*s++ = 'w';
  64	if (c & CEPH_CAP_GBUFFER)
  65		*s++ = 'b';
  66	if (c & CEPH_CAP_GLAZYIO)
  67		*s++ = 'l';
  68	return s;
  69}
  70
  71const char *ceph_cap_string(int caps)
  72{
  73	int i;
  74	char *s;
  75	int c;
  76
  77	spin_lock(&cap_str_lock);
  78	i = last_cap_str++;
  79	if (last_cap_str == MAX_CAP_STR)
  80		last_cap_str = 0;
  81	spin_unlock(&cap_str_lock);
  82
  83	s = cap_str[i];
  84
  85	if (caps & CEPH_CAP_PIN)
  86		*s++ = 'p';
  87
  88	c = (caps >> CEPH_CAP_SAUTH) & 3;
  89	if (c) {
  90		*s++ = 'A';
  91		s = gcap_string(s, c);
  92	}
  93
  94	c = (caps >> CEPH_CAP_SLINK) & 3;
  95	if (c) {
  96		*s++ = 'L';
  97		s = gcap_string(s, c);
  98	}
  99
 100	c = (caps >> CEPH_CAP_SXATTR) & 3;
 101	if (c) {
 102		*s++ = 'X';
 103		s = gcap_string(s, c);
 104	}
 105
 106	c = caps >> CEPH_CAP_SFILE;
 107	if (c) {
 108		*s++ = 'F';
 109		s = gcap_string(s, c);
 110	}
 111
 112	if (s == cap_str[i])
 113		*s++ = '-';
 114	*s = 0;
 115	return cap_str[i];
 116}
 117
 118void ceph_caps_init(struct ceph_mds_client *mdsc)
 119{
 120	INIT_LIST_HEAD(&mdsc->caps_list);
 121	spin_lock_init(&mdsc->caps_list_lock);
 122}
 123
 124void ceph_caps_finalize(struct ceph_mds_client *mdsc)
 125{
 126	struct ceph_cap *cap;
 127
 128	spin_lock(&mdsc->caps_list_lock);
 129	while (!list_empty(&mdsc->caps_list)) {
 130		cap = list_first_entry(&mdsc->caps_list,
 131				       struct ceph_cap, caps_item);
 132		list_del(&cap->caps_item);
 133		kmem_cache_free(ceph_cap_cachep, cap);
 134	}
 135	mdsc->caps_total_count = 0;
 136	mdsc->caps_avail_count = 0;
 137	mdsc->caps_use_count = 0;
 138	mdsc->caps_reserve_count = 0;
 139	mdsc->caps_min_count = 0;
 140	spin_unlock(&mdsc->caps_list_lock);
 141}
 142
 143void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
 144{
 145	spin_lock(&mdsc->caps_list_lock);
 146	mdsc->caps_min_count += delta;
 147	BUG_ON(mdsc->caps_min_count < 0);
 148	spin_unlock(&mdsc->caps_list_lock);
 149}
 150
 151void ceph_reserve_caps(struct ceph_mds_client *mdsc,
 152		      struct ceph_cap_reservation *ctx, int need)
 153{
 154	int i;
 155	struct ceph_cap *cap;
 156	int have;
 157	int alloc = 0;
 158	LIST_HEAD(newcaps);
 
 159
 160	dout("reserve caps ctx=%p need=%d\n", ctx, need);
 161
 162	/* first reserve any caps that are already allocated */
 163	spin_lock(&mdsc->caps_list_lock);
 164	if (mdsc->caps_avail_count >= need)
 165		have = need;
 166	else
 167		have = mdsc->caps_avail_count;
 168	mdsc->caps_avail_count -= have;
 169	mdsc->caps_reserve_count += have;
 170	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 171					 mdsc->caps_reserve_count +
 172					 mdsc->caps_avail_count);
 173	spin_unlock(&mdsc->caps_list_lock);
 174
 175	for (i = have; i < need; i++) {
 176		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 177		if (!cap)
 178			break;
 
 
 179		list_add(&cap->caps_item, &newcaps);
 180		alloc++;
 181	}
 182	/* we didn't manage to reserve as much as we needed */
 183	if (have + alloc != need)
 184		pr_warn("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
 185			ctx, need, have + alloc);
 186
 187	spin_lock(&mdsc->caps_list_lock);
 188	mdsc->caps_total_count += alloc;
 189	mdsc->caps_reserve_count += alloc;
 190	list_splice(&newcaps, &mdsc->caps_list);
 191
 192	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 193					 mdsc->caps_reserve_count +
 194					 mdsc->caps_avail_count);
 195	spin_unlock(&mdsc->caps_list_lock);
 196
 197	ctx->count = need;
 198	dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
 199	     ctx, mdsc->caps_total_count, mdsc->caps_use_count,
 200	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 
 
 
 
 
 
 
 201}
 202
 203int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 204			struct ceph_cap_reservation *ctx)
 205{
 206	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
 207	if (ctx->count) {
 208		spin_lock(&mdsc->caps_list_lock);
 209		BUG_ON(mdsc->caps_reserve_count < ctx->count);
 210		mdsc->caps_reserve_count -= ctx->count;
 211		mdsc->caps_avail_count += ctx->count;
 212		ctx->count = 0;
 213		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
 214		     mdsc->caps_total_count, mdsc->caps_use_count,
 215		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 216		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 217						 mdsc->caps_reserve_count +
 218						 mdsc->caps_avail_count);
 219		spin_unlock(&mdsc->caps_list_lock);
 220	}
 221	return 0;
 222}
 223
 224static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
 225				struct ceph_cap_reservation *ctx)
 226{
 227	struct ceph_cap *cap = NULL;
 228
 229	/* temporary, until we do something about cap import/export */
 230	if (!ctx) {
 231		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 232		if (cap) {
 233			spin_lock(&mdsc->caps_list_lock);
 234			mdsc->caps_use_count++;
 235			mdsc->caps_total_count++;
 236			spin_unlock(&mdsc->caps_list_lock);
 237		}
 238		return cap;
 239	}
 240
 241	spin_lock(&mdsc->caps_list_lock);
 242	dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
 243	     ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
 244	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 245	BUG_ON(!ctx->count);
 246	BUG_ON(ctx->count > mdsc->caps_reserve_count);
 247	BUG_ON(list_empty(&mdsc->caps_list));
 248
 249	ctx->count--;
 250	mdsc->caps_reserve_count--;
 251	mdsc->caps_use_count++;
 252
 253	cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
 254	list_del(&cap->caps_item);
 255
 256	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 257	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
 258	spin_unlock(&mdsc->caps_list_lock);
 259	return cap;
 260}
 261
 262void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
 263{
 264	spin_lock(&mdsc->caps_list_lock);
 265	dout("put_cap %p %d = %d used + %d resv + %d avail\n",
 266	     cap, mdsc->caps_total_count, mdsc->caps_use_count,
 267	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 268	mdsc->caps_use_count--;
 269	/*
 270	 * Keep some preallocated caps around (ceph_min_count), to
 271	 * avoid lots of free/alloc churn.
 272	 */
 273	if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
 274				      mdsc->caps_min_count) {
 275		mdsc->caps_total_count--;
 276		kmem_cache_free(ceph_cap_cachep, cap);
 277	} else {
 278		mdsc->caps_avail_count++;
 279		list_add(&cap->caps_item, &mdsc->caps_list);
 280	}
 281
 282	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 283	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
 284	spin_unlock(&mdsc->caps_list_lock);
 285}
 286
 287void ceph_reservation_status(struct ceph_fs_client *fsc,
 288			     int *total, int *avail, int *used, int *reserved,
 289			     int *min)
 290{
 291	struct ceph_mds_client *mdsc = fsc->mdsc;
 292
 293	if (total)
 294		*total = mdsc->caps_total_count;
 295	if (avail)
 296		*avail = mdsc->caps_avail_count;
 297	if (used)
 298		*used = mdsc->caps_use_count;
 299	if (reserved)
 300		*reserved = mdsc->caps_reserve_count;
 301	if (min)
 302		*min = mdsc->caps_min_count;
 303}
 304
 305/*
 306 * Find ceph_cap for given mds, if any.
 307 *
 308 * Called with i_ceph_lock held.
 309 */
 310static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 311{
 312	struct ceph_cap *cap;
 313	struct rb_node *n = ci->i_caps.rb_node;
 314
 315	while (n) {
 316		cap = rb_entry(n, struct ceph_cap, ci_node);
 317		if (mds < cap->mds)
 318			n = n->rb_left;
 319		else if (mds > cap->mds)
 320			n = n->rb_right;
 321		else
 322			return cap;
 323	}
 324	return NULL;
 325}
 326
 327struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 328{
 329	struct ceph_cap *cap;
 330
 331	spin_lock(&ci->i_ceph_lock);
 332	cap = __get_cap_for_mds(ci, mds);
 333	spin_unlock(&ci->i_ceph_lock);
 334	return cap;
 335}
 336
 337/*
 338 * Return id of any MDS with a cap, preferably FILE_WR|BUFFER|EXCL, else -1.
 339 */
 340static int __ceph_get_cap_mds(struct ceph_inode_info *ci)
 341{
 342	struct ceph_cap *cap;
 343	int mds = -1;
 344	struct rb_node *p;
 345
 346	/* prefer mds with WR|BUFFER|EXCL caps */
 347	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 348		cap = rb_entry(p, struct ceph_cap, ci_node);
 349		mds = cap->mds;
 350		if (cap->issued & (CEPH_CAP_FILE_WR |
 351				   CEPH_CAP_FILE_BUFFER |
 352				   CEPH_CAP_FILE_EXCL))
 353			break;
 354	}
 355	return mds;
 356}
 357
 358int ceph_get_cap_mds(struct inode *inode)
 359{
 360	struct ceph_inode_info *ci = ceph_inode(inode);
 361	int mds;
 362	spin_lock(&ci->i_ceph_lock);
 363	mds = __ceph_get_cap_mds(ceph_inode(inode));
 364	spin_unlock(&ci->i_ceph_lock);
 365	return mds;
 366}
 367
 368/*
 369 * Called under i_ceph_lock.
 370 */
 371static void __insert_cap_node(struct ceph_inode_info *ci,
 372			      struct ceph_cap *new)
 373{
 374	struct rb_node **p = &ci->i_caps.rb_node;
 375	struct rb_node *parent = NULL;
 376	struct ceph_cap *cap = NULL;
 377
 378	while (*p) {
 379		parent = *p;
 380		cap = rb_entry(parent, struct ceph_cap, ci_node);
 381		if (new->mds < cap->mds)
 382			p = &(*p)->rb_left;
 383		else if (new->mds > cap->mds)
 384			p = &(*p)->rb_right;
 385		else
 386			BUG();
 387	}
 388
 389	rb_link_node(&new->ci_node, parent, p);
 390	rb_insert_color(&new->ci_node, &ci->i_caps);
 391}
 392
 393/*
 394 * (re)set cap hold timeouts, which control the delayed release
 395 * of unused caps back to the MDS.  Should be called on cap use.
 396 */
 397static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
 398			       struct ceph_inode_info *ci)
 399{
 400	struct ceph_mount_options *ma = mdsc->fsc->mount_options;
 401
 402	ci->i_hold_caps_min = round_jiffies(jiffies +
 403					    ma->caps_wanted_delay_min * HZ);
 404	ci->i_hold_caps_max = round_jiffies(jiffies +
 405					    ma->caps_wanted_delay_max * HZ);
 406	dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
 407	     ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
 408}
 409
 410/*
 411 * (Re)queue cap at the end of the delayed cap release list.
 412 *
 413 * If I_FLUSH is set, leave the inode at the front of the list.
 414 *
 415 * Caller holds i_ceph_lock
 416 *    -> we take mdsc->cap_delay_lock
 417 */
 418static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
 419				struct ceph_inode_info *ci)
 420{
 421	__cap_set_timeouts(mdsc, ci);
 422	dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
 423	     ci->i_ceph_flags, ci->i_hold_caps_max);
 424	if (!mdsc->stopping) {
 425		spin_lock(&mdsc->cap_delay_lock);
 426		if (!list_empty(&ci->i_cap_delay_list)) {
 427			if (ci->i_ceph_flags & CEPH_I_FLUSH)
 428				goto no_change;
 429			list_del_init(&ci->i_cap_delay_list);
 430		}
 431		list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 432no_change:
 433		spin_unlock(&mdsc->cap_delay_lock);
 434	}
 435}
 436
 437/*
 438 * Queue an inode for immediate writeback.  Mark inode with I_FLUSH,
 439 * indicating we should send a cap message to flush dirty metadata
 440 * asap, and move to the front of the delayed cap list.
 441 */
 442static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
 443				      struct ceph_inode_info *ci)
 444{
 445	dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
 446	spin_lock(&mdsc->cap_delay_lock);
 447	ci->i_ceph_flags |= CEPH_I_FLUSH;
 448	if (!list_empty(&ci->i_cap_delay_list))
 449		list_del_init(&ci->i_cap_delay_list);
 450	list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 451	spin_unlock(&mdsc->cap_delay_lock);
 452}
 453
 454/*
 455 * Cancel delayed work on cap.
 456 *
 457 * Caller must hold i_ceph_lock.
 458 */
 459static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
 460			       struct ceph_inode_info *ci)
 461{
 462	dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
 463	if (list_empty(&ci->i_cap_delay_list))
 464		return;
 465	spin_lock(&mdsc->cap_delay_lock);
 466	list_del_init(&ci->i_cap_delay_list);
 467	spin_unlock(&mdsc->cap_delay_lock);
 468}
 469
 470/*
 471 * Common issue checks for add_cap, handle_cap_grant.
 472 */
 473static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
 474			      unsigned issued)
 475{
 476	unsigned had = __ceph_caps_issued(ci, NULL);
 477
 478	/*
 479	 * Each time we receive FILE_CACHE anew, we increment
 480	 * i_rdcache_gen.
 481	 */
 482	if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
 483	    (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) {
 484		ci->i_rdcache_gen++;
 485	}
 486
 487	/*
 488	 * if we are newly issued FILE_SHARED, mark dir not complete; we
 489	 * don't know what happened to this directory while we didn't
 490	 * have the cap.
 491	 */
 492	if ((issued & CEPH_CAP_FILE_SHARED) &&
 493	    (had & CEPH_CAP_FILE_SHARED) == 0) {
 494		ci->i_shared_gen++;
 495		if (S_ISDIR(ci->vfs_inode.i_mode)) {
 496			dout(" marking %p NOT complete\n", &ci->vfs_inode);
 497			__ceph_dir_clear_complete(ci);
 498		}
 499	}
 500}
 501
 502/*
 503 * Add a capability under the given MDS session.
 504 *
 505 * Caller should hold session snap_rwsem (read) and s_mutex.
 506 *
 507 * @fmode is the open file mode, if we are opening a file, otherwise
 508 * it is < 0.  (This is so we can atomically add the cap and add an
 509 * open file reference to it.)
 510 */
 511int ceph_add_cap(struct inode *inode,
 512		 struct ceph_mds_session *session, u64 cap_id,
 513		 int fmode, unsigned issued, unsigned wanted,
 514		 unsigned seq, unsigned mseq, u64 realmino, int flags,
 515		 struct ceph_cap_reservation *caps_reservation)
 516{
 517	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 518	struct ceph_inode_info *ci = ceph_inode(inode);
 519	struct ceph_cap *new_cap = NULL;
 520	struct ceph_cap *cap;
 521	int mds = session->s_mds;
 522	int actual_wanted;
 523
 524	dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
 525	     session->s_mds, cap_id, ceph_cap_string(issued), seq);
 526
 527	/*
 528	 * If we are opening the file, include file mode wanted bits
 529	 * in wanted.
 530	 */
 531	if (fmode >= 0)
 532		wanted |= ceph_caps_for_mode(fmode);
 533
 534retry:
 535	spin_lock(&ci->i_ceph_lock);
 536	cap = __get_cap_for_mds(ci, mds);
 537	if (!cap) {
 538		if (new_cap) {
 539			cap = new_cap;
 540			new_cap = NULL;
 541		} else {
 542			spin_unlock(&ci->i_ceph_lock);
 543			new_cap = get_cap(mdsc, caps_reservation);
 544			if (new_cap == NULL)
 545				return -ENOMEM;
 546			goto retry;
 547		}
 548
 549		cap->issued = 0;
 550		cap->implemented = 0;
 551		cap->mds = mds;
 552		cap->mds_wanted = 0;
 553		cap->mseq = 0;
 554
 555		cap->ci = ci;
 556		__insert_cap_node(ci, cap);
 557
 
 
 
 
 
 
 
 558		/* add to session cap list */
 559		cap->session = session;
 560		spin_lock(&session->s_cap_lock);
 561		list_add_tail(&cap->session_caps, &session->s_caps);
 562		session->s_nr_caps++;
 563		spin_unlock(&session->s_cap_lock);
 564	} else {
 565		if (new_cap)
 566			ceph_put_cap(mdsc, new_cap);
 567
 568		/*
 569		 * auth mds of the inode changed. we received the cap export
 570		 * message, but still haven't received the cap import message.
 571		 * handle_cap_export() updated the new auth MDS' cap.
 572		 *
 573		 * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing
 574		 * a message that was send before the cap import message. So
 575		 * don't remove caps.
 576		 */
 577		if (ceph_seq_cmp(seq, cap->seq) <= 0) {
 578			WARN_ON(cap != ci->i_auth_cap);
 579			WARN_ON(cap->cap_id != cap_id);
 580			seq = cap->seq;
 581			mseq = cap->mseq;
 582			issued |= cap->issued;
 583			flags |= CEPH_CAP_FLAG_AUTH;
 584		}
 585	}
 586
 587	if (!ci->i_snap_realm) {
 588		/*
 589		 * add this inode to the appropriate snap realm
 590		 */
 591		struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
 592							       realmino);
 593		if (realm) {
 594			ceph_get_snap_realm(mdsc, realm);
 595			spin_lock(&realm->inodes_with_caps_lock);
 596			ci->i_snap_realm = realm;
 597			list_add(&ci->i_snap_realm_item,
 598				 &realm->inodes_with_caps);
 599			spin_unlock(&realm->inodes_with_caps_lock);
 600		} else {
 601			pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
 602			       realmino);
 603			WARN_ON(!realm);
 604		}
 605	}
 606
 607	__check_cap_issue(ci, cap, issued);
 608
 609	/*
 610	 * If we are issued caps we don't want, or the mds' wanted
 611	 * value appears to be off, queue a check so we'll release
 612	 * later and/or update the mds wanted value.
 613	 */
 614	actual_wanted = __ceph_caps_wanted(ci);
 615	if ((wanted & ~actual_wanted) ||
 616	    (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
 617		dout(" issued %s, mds wanted %s, actual %s, queueing\n",
 618		     ceph_cap_string(issued), ceph_cap_string(wanted),
 619		     ceph_cap_string(actual_wanted));
 620		__cap_delay_requeue(mdsc, ci);
 621	}
 622
 623	if (flags & CEPH_CAP_FLAG_AUTH) {
 624		if (ci->i_auth_cap == NULL ||
 625		    ceph_seq_cmp(ci->i_auth_cap->mseq, mseq) < 0) {
 626			ci->i_auth_cap = cap;
 627			cap->mds_wanted = wanted;
 628		}
 629		ci->i_cap_exporting_issued = 0;
 630	} else {
 631		WARN_ON(ci->i_auth_cap == cap);
 632	}
 633
 634	dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
 635	     inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
 636	     ceph_cap_string(issued|cap->issued), seq, mds);
 637	cap->cap_id = cap_id;
 638	cap->issued = issued;
 639	cap->implemented |= issued;
 640	if (ceph_seq_cmp(mseq, cap->mseq) > 0)
 641		cap->mds_wanted = wanted;
 642	else
 643		cap->mds_wanted |= wanted;
 644	cap->seq = seq;
 645	cap->issue_seq = seq;
 646	cap->mseq = mseq;
 647	cap->cap_gen = session->s_cap_gen;
 648
 649	if (fmode >= 0)
 650		__ceph_get_fmode(ci, fmode);
 651	spin_unlock(&ci->i_ceph_lock);
 652	wake_up_all(&ci->i_cap_wq);
 653	return 0;
 654}
 655
 656/*
 657 * Return true if cap has not timed out and belongs to the current
 658 * generation of the MDS session (i.e. has not gone 'stale' due to
 659 * us losing touch with the mds).
 660 */
 661static int __cap_is_valid(struct ceph_cap *cap)
 662{
 663	unsigned long ttl;
 664	u32 gen;
 665
 666	spin_lock(&cap->session->s_gen_ttl_lock);
 667	gen = cap->session->s_cap_gen;
 668	ttl = cap->session->s_cap_ttl;
 669	spin_unlock(&cap->session->s_gen_ttl_lock);
 670
 671	if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
 672		dout("__cap_is_valid %p cap %p issued %s "
 673		     "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
 674		     cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
 675		return 0;
 676	}
 677
 678	return 1;
 679}
 680
 681/*
 682 * Return set of valid cap bits issued to us.  Note that caps time
 683 * out, and may be invalidated in bulk if the client session times out
 684 * and session->s_cap_gen is bumped.
 685 */
 686int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
 687{
 688	int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
 689	struct ceph_cap *cap;
 690	struct rb_node *p;
 691
 692	if (implemented)
 693		*implemented = 0;
 694	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 695		cap = rb_entry(p, struct ceph_cap, ci_node);
 696		if (!__cap_is_valid(cap))
 697			continue;
 698		dout("__ceph_caps_issued %p cap %p issued %s\n",
 699		     &ci->vfs_inode, cap, ceph_cap_string(cap->issued));
 700		have |= cap->issued;
 701		if (implemented)
 702			*implemented |= cap->implemented;
 703	}
 704	/*
 705	 * exclude caps issued by non-auth MDS, but are been revoking
 706	 * by the auth MDS. The non-auth MDS should be revoking/exporting
 707	 * these caps, but the message is delayed.
 708	 */
 709	if (ci->i_auth_cap) {
 710		cap = ci->i_auth_cap;
 711		have &= ~cap->implemented | cap->issued;
 712	}
 713	return have;
 714}
 715
 716/*
 717 * Get cap bits issued by caps other than @ocap
 718 */
 719int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
 720{
 721	int have = ci->i_snap_caps;
 722	struct ceph_cap *cap;
 723	struct rb_node *p;
 724
 725	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 726		cap = rb_entry(p, struct ceph_cap, ci_node);
 727		if (cap == ocap)
 728			continue;
 729		if (!__cap_is_valid(cap))
 730			continue;
 731		have |= cap->issued;
 732	}
 733	return have;
 734}
 735
 736/*
 737 * Move a cap to the end of the LRU (oldest caps at list head, newest
 738 * at list tail).
 739 */
 740static void __touch_cap(struct ceph_cap *cap)
 741{
 742	struct ceph_mds_session *s = cap->session;
 743
 744	spin_lock(&s->s_cap_lock);
 745	if (s->s_cap_iterator == NULL) {
 746		dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
 747		     s->s_mds);
 748		list_move_tail(&cap->session_caps, &s->s_caps);
 749	} else {
 750		dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
 751		     &cap->ci->vfs_inode, cap, s->s_mds);
 752	}
 753	spin_unlock(&s->s_cap_lock);
 754}
 755
 756/*
 757 * Check if we hold the given mask.  If so, move the cap(s) to the
 758 * front of their respective LRUs.  (This is the preferred way for
 759 * callers to check for caps they want.)
 760 */
 761int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
 762{
 763	struct ceph_cap *cap;
 764	struct rb_node *p;
 765	int have = ci->i_snap_caps;
 766
 767	if ((have & mask) == mask) {
 768		dout("__ceph_caps_issued_mask %p snap issued %s"
 769		     " (mask %s)\n", &ci->vfs_inode,
 770		     ceph_cap_string(have),
 771		     ceph_cap_string(mask));
 772		return 1;
 773	}
 774
 775	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 776		cap = rb_entry(p, struct ceph_cap, ci_node);
 777		if (!__cap_is_valid(cap))
 778			continue;
 779		if ((cap->issued & mask) == mask) {
 780			dout("__ceph_caps_issued_mask %p cap %p issued %s"
 781			     " (mask %s)\n", &ci->vfs_inode, cap,
 782			     ceph_cap_string(cap->issued),
 783			     ceph_cap_string(mask));
 784			if (touch)
 785				__touch_cap(cap);
 786			return 1;
 787		}
 788
 789		/* does a combination of caps satisfy mask? */
 790		have |= cap->issued;
 791		if ((have & mask) == mask) {
 792			dout("__ceph_caps_issued_mask %p combo issued %s"
 793			     " (mask %s)\n", &ci->vfs_inode,
 794			     ceph_cap_string(cap->issued),
 795			     ceph_cap_string(mask));
 796			if (touch) {
 797				struct rb_node *q;
 798
 799				/* touch this + preceding caps */
 800				__touch_cap(cap);
 801				for (q = rb_first(&ci->i_caps); q != p;
 802				     q = rb_next(q)) {
 803					cap = rb_entry(q, struct ceph_cap,
 804						       ci_node);
 805					if (!__cap_is_valid(cap))
 806						continue;
 807					__touch_cap(cap);
 808				}
 809			}
 810			return 1;
 811		}
 812	}
 813
 814	return 0;
 815}
 816
 817/*
 818 * Return true if mask caps are currently being revoked by an MDS.
 819 */
 820int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
 821			       struct ceph_cap *ocap, int mask)
 822{
 
 823	struct ceph_cap *cap;
 824	struct rb_node *p;
 
 825
 
 826	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 827		cap = rb_entry(p, struct ceph_cap, ci_node);
 828		if (cap != ocap &&
 829		    (cap->implemented & ~cap->issued & mask))
 830			return 1;
 
 
 831	}
 832	return 0;
 833}
 834
 835int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
 836{
 837	struct inode *inode = &ci->vfs_inode;
 838	int ret;
 839
 840	spin_lock(&ci->i_ceph_lock);
 841	ret = __ceph_caps_revoking_other(ci, NULL, mask);
 842	spin_unlock(&ci->i_ceph_lock);
 843	dout("ceph_caps_revoking %p %s = %d\n", inode,
 844	     ceph_cap_string(mask), ret);
 845	return ret;
 846}
 847
 848int __ceph_caps_used(struct ceph_inode_info *ci)
 849{
 850	int used = 0;
 851	if (ci->i_pin_ref)
 852		used |= CEPH_CAP_PIN;
 853	if (ci->i_rd_ref)
 854		used |= CEPH_CAP_FILE_RD;
 855	if (ci->i_rdcache_ref || ci->vfs_inode.i_data.nrpages)
 856		used |= CEPH_CAP_FILE_CACHE;
 857	if (ci->i_wr_ref)
 858		used |= CEPH_CAP_FILE_WR;
 859	if (ci->i_wb_ref || ci->i_wrbuffer_ref)
 860		used |= CEPH_CAP_FILE_BUFFER;
 861	return used;
 862}
 863
 864/*
 865 * wanted, by virtue of open file modes
 866 */
 867int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
 868{
 869	int want = 0;
 870	int mode;
 871	for (mode = 0; mode < CEPH_FILE_MODE_NUM; mode++)
 872		if (ci->i_nr_by_mode[mode])
 873			want |= ceph_caps_for_mode(mode);
 874	return want;
 875}
 876
 877/*
 878 * Return caps we have registered with the MDS(s) as 'wanted'.
 879 */
 880int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
 881{
 882	struct ceph_cap *cap;
 883	struct rb_node *p;
 884	int mds_wanted = 0;
 885
 886	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 887		cap = rb_entry(p, struct ceph_cap, ci_node);
 888		if (!__cap_is_valid(cap))
 889			continue;
 890		if (cap == ci->i_auth_cap)
 891			mds_wanted |= cap->mds_wanted;
 892		else
 893			mds_wanted |= (cap->mds_wanted & ~CEPH_CAP_ANY_FILE_WR);
 894	}
 895	return mds_wanted;
 896}
 897
 898/*
 899 * called under i_ceph_lock
 900 */
 901static int __ceph_is_any_caps(struct ceph_inode_info *ci)
 902{
 903	return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_issued;
 904}
 905
 906int ceph_is_any_caps(struct inode *inode)
 907{
 908	struct ceph_inode_info *ci = ceph_inode(inode);
 909	int ret;
 910
 911	spin_lock(&ci->i_ceph_lock);
 912	ret = __ceph_is_any_caps(ci);
 913	spin_unlock(&ci->i_ceph_lock);
 914
 915	return ret;
 916}
 917
 918/*
 919 * Remove a cap.  Take steps to deal with a racing iterate_session_caps.
 920 *
 921 * caller should hold i_ceph_lock.
 922 * caller will not hold session s_mutex if called from destroy_inode.
 923 */
 924void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release)
 925{
 926	struct ceph_mds_session *session = cap->session;
 927	struct ceph_inode_info *ci = cap->ci;
 928	struct ceph_mds_client *mdsc =
 929		ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
 930	int removed = 0;
 931
 932	dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
 933
 934	/* remove from session list */
 935	spin_lock(&session->s_cap_lock);
 936	/*
 937	 * s_cap_reconnect is protected by s_cap_lock. no one changes
 938	 * s_cap_gen while session is in the reconnect state.
 939	 */
 940	if (queue_release &&
 941	    (!session->s_cap_reconnect ||
 942	     cap->cap_gen == session->s_cap_gen))
 943		__queue_cap_release(session, ci->i_vino.ino, cap->cap_id,
 944				    cap->mseq, cap->issue_seq);
 945
 946	if (session->s_cap_iterator == cap) {
 947		/* not yet, we are iterating over this very cap */
 948		dout("__ceph_remove_cap  delaying %p removal from session %p\n",
 949		     cap, cap->session);
 950	} else {
 951		list_del_init(&cap->session_caps);
 952		session->s_nr_caps--;
 953		cap->session = NULL;
 954		removed = 1;
 955	}
 956	/* protect backpointer with s_cap_lock: see iterate_session_caps */
 957	cap->ci = NULL;
 958	spin_unlock(&session->s_cap_lock);
 959
 960	/* remove from inode list */
 961	rb_erase(&cap->ci_node, &ci->i_caps);
 962	if (ci->i_auth_cap == cap)
 963		ci->i_auth_cap = NULL;
 964
 965	if (removed)
 966		ceph_put_cap(mdsc, cap);
 967
 968	if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
 969		struct ceph_snap_realm *realm = ci->i_snap_realm;
 970		spin_lock(&realm->inodes_with_caps_lock);
 971		list_del_init(&ci->i_snap_realm_item);
 972		ci->i_snap_realm_counter++;
 973		ci->i_snap_realm = NULL;
 974		spin_unlock(&realm->inodes_with_caps_lock);
 975		ceph_put_snap_realm(mdsc, realm);
 976	}
 977	if (!__ceph_is_any_real_caps(ci))
 978		__cap_delay_cancel(mdsc, ci);
 979}
 980
 981/*
 982 * Build and send a cap message to the given MDS.
 983 *
 984 * Caller should be holding s_mutex.
 985 */
 986static int send_cap_msg(struct ceph_mds_session *session,
 987			u64 ino, u64 cid, int op,
 988			int caps, int wanted, int dirty,
 989			u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq,
 990			u64 size, u64 max_size,
 991			struct timespec *mtime, struct timespec *atime,
 992			u64 time_warp_seq,
 993			kuid_t uid, kgid_t gid, umode_t mode,
 994			u64 xattr_version,
 995			struct ceph_buffer *xattrs_buf,
 996			u64 follows)
 997{
 998	struct ceph_mds_caps *fc;
 999	struct ceph_msg *msg;
1000
1001	dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
1002	     " seq %u/%u mseq %u follows %lld size %llu/%llu"
1003	     " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op),
1004	     cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
1005	     ceph_cap_string(dirty),
1006	     seq, issue_seq, mseq, follows, size, max_size,
1007	     xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
1008
1009	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), GFP_NOFS, false);
1010	if (!msg)
1011		return -ENOMEM;
1012
1013	msg->hdr.tid = cpu_to_le64(flush_tid);
1014
1015	fc = msg->front.iov_base;
1016	memset(fc, 0, sizeof(*fc));
1017
1018	fc->cap_id = cpu_to_le64(cid);
1019	fc->op = cpu_to_le32(op);
1020	fc->seq = cpu_to_le32(seq);
1021	fc->issue_seq = cpu_to_le32(issue_seq);
1022	fc->migrate_seq = cpu_to_le32(mseq);
1023	fc->caps = cpu_to_le32(caps);
1024	fc->wanted = cpu_to_le32(wanted);
1025	fc->dirty = cpu_to_le32(dirty);
1026	fc->ino = cpu_to_le64(ino);
1027	fc->snap_follows = cpu_to_le64(follows);
1028
1029	fc->size = cpu_to_le64(size);
1030	fc->max_size = cpu_to_le64(max_size);
1031	if (mtime)
1032		ceph_encode_timespec(&fc->mtime, mtime);
1033	if (atime)
1034		ceph_encode_timespec(&fc->atime, atime);
1035	fc->time_warp_seq = cpu_to_le32(time_warp_seq);
1036
1037	fc->uid = cpu_to_le32(from_kuid(&init_user_ns, uid));
1038	fc->gid = cpu_to_le32(from_kgid(&init_user_ns, gid));
1039	fc->mode = cpu_to_le32(mode);
1040
1041	fc->xattr_version = cpu_to_le64(xattr_version);
1042	if (xattrs_buf) {
1043		msg->middle = ceph_buffer_get(xattrs_buf);
1044		fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len);
1045		msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len);
1046	}
1047
1048	ceph_con_send(&session->s_con, msg);
1049	return 0;
1050}
1051
1052void __queue_cap_release(struct ceph_mds_session *session,
1053			 u64 ino, u64 cap_id, u32 migrate_seq,
1054			 u32 issue_seq)
1055{
1056	struct ceph_msg *msg;
1057	struct ceph_mds_cap_release *head;
1058	struct ceph_mds_cap_item *item;
1059
 
1060	BUG_ON(!session->s_num_cap_releases);
1061	msg = list_first_entry(&session->s_cap_releases,
1062			       struct ceph_msg, list_head);
1063
1064	dout(" adding %llx release to mds%d msg %p (%d left)\n",
1065	     ino, session->s_mds, msg, session->s_num_cap_releases);
1066
1067	BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
1068	head = msg->front.iov_base;
1069	le32_add_cpu(&head->num, 1);
1070	item = msg->front.iov_base + msg->front.iov_len;
1071	item->ino = cpu_to_le64(ino);
1072	item->cap_id = cpu_to_le64(cap_id);
1073	item->migrate_seq = cpu_to_le32(migrate_seq);
1074	item->seq = cpu_to_le32(issue_seq);
1075
1076	session->s_num_cap_releases--;
1077
1078	msg->front.iov_len += sizeof(*item);
1079	if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1080		dout(" release msg %p full\n", msg);
1081		list_move_tail(&msg->list_head, &session->s_cap_releases_done);
1082	} else {
1083		dout(" release msg %p at %d/%d (%d)\n", msg,
1084		     (int)le32_to_cpu(head->num),
1085		     (int)CEPH_CAPS_PER_RELEASE,
1086		     (int)msg->front.iov_len);
1087	}
 
1088}
1089
1090/*
1091 * Queue cap releases when an inode is dropped from our cache.  Since
1092 * inode is about to be destroyed, there is no need for i_ceph_lock.
1093 */
1094void ceph_queue_caps_release(struct inode *inode)
1095{
1096	struct ceph_inode_info *ci = ceph_inode(inode);
1097	struct rb_node *p;
1098
1099	p = rb_first(&ci->i_caps);
1100	while (p) {
1101		struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
 
 
 
 
1102		p = rb_next(p);
1103		__ceph_remove_cap(cap, true);
1104	}
1105}
1106
1107/*
1108 * Send a cap msg on the given inode.  Update our caps state, then
1109 * drop i_ceph_lock and send the message.
1110 *
1111 * Make note of max_size reported/requested from mds, revoked caps
1112 * that have now been implemented.
1113 *
1114 * Make half-hearted attempt ot to invalidate page cache if we are
1115 * dropping RDCACHE.  Note that this will leave behind locked pages
1116 * that we'll then need to deal with elsewhere.
1117 *
1118 * Return non-zero if delayed release, or we experienced an error
1119 * such that the caller should requeue + retry later.
1120 *
1121 * called with i_ceph_lock, then drops it.
1122 * caller should hold snap_rwsem (read), s_mutex.
1123 */
1124static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
1125		      int op, int used, int want, int retain, int flushing,
1126		      unsigned *pflush_tid)
1127	__releases(cap->ci->i_ceph_lock)
1128{
1129	struct ceph_inode_info *ci = cap->ci;
1130	struct inode *inode = &ci->vfs_inode;
1131	u64 cap_id = cap->cap_id;
1132	int held, revoking, dropping, keep;
1133	u64 seq, issue_seq, mseq, time_warp_seq, follows;
1134	u64 size, max_size;
1135	struct timespec mtime, atime;
1136	int wake = 0;
1137	umode_t mode;
1138	kuid_t uid;
1139	kgid_t gid;
1140	struct ceph_mds_session *session;
1141	u64 xattr_version = 0;
1142	struct ceph_buffer *xattr_blob = NULL;
1143	int delayed = 0;
1144	u64 flush_tid = 0;
1145	int i;
1146	int ret;
1147
1148	held = cap->issued | cap->implemented;
1149	revoking = cap->implemented & ~cap->issued;
1150	retain &= ~revoking;
1151	dropping = cap->issued & ~retain;
1152
1153	dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
1154	     inode, cap, cap->session,
1155	     ceph_cap_string(held), ceph_cap_string(held & retain),
1156	     ceph_cap_string(revoking));
1157	BUG_ON((retain & CEPH_CAP_PIN) == 0);
1158
1159	session = cap->session;
1160
1161	/* don't release wanted unless we've waited a bit. */
1162	if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1163	    time_before(jiffies, ci->i_hold_caps_min)) {
1164		dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
1165		     ceph_cap_string(cap->issued),
1166		     ceph_cap_string(cap->issued & retain),
1167		     ceph_cap_string(cap->mds_wanted),
1168		     ceph_cap_string(want));
1169		want |= cap->mds_wanted;
1170		retain |= cap->issued;
1171		delayed = 1;
1172	}
1173	ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
1174
1175	cap->issued &= retain;  /* drop bits we don't want */
1176	if (cap->implemented & ~cap->issued) {
1177		/*
1178		 * Wake up any waiters on wanted -> needed transition.
1179		 * This is due to the weird transition from buffered
1180		 * to sync IO... we need to flush dirty pages _before_
1181		 * allowing sync writes to avoid reordering.
1182		 */
1183		wake = 1;
1184	}
1185	cap->implemented &= cap->issued | used;
1186	cap->mds_wanted = want;
1187
1188	if (flushing) {
1189		/*
1190		 * assign a tid for flush operations so we can avoid
1191		 * flush1 -> dirty1 -> flush2 -> flushack1 -> mark
1192		 * clean type races.  track latest tid for every bit
1193		 * so we can handle flush AxFw, flush Fw, and have the
1194		 * first ack clean Ax.
1195		 */
1196		flush_tid = ++ci->i_cap_flush_last_tid;
1197		if (pflush_tid)
1198			*pflush_tid = flush_tid;
1199		dout(" cap_flush_tid %d\n", (int)flush_tid);
1200		for (i = 0; i < CEPH_CAP_BITS; i++)
1201			if (flushing & (1 << i))
1202				ci->i_cap_flush_tid[i] = flush_tid;
1203
1204		follows = ci->i_head_snapc->seq;
1205	} else {
1206		follows = 0;
1207	}
1208
1209	keep = cap->implemented;
1210	seq = cap->seq;
1211	issue_seq = cap->issue_seq;
1212	mseq = cap->mseq;
1213	size = inode->i_size;
1214	ci->i_reported_size = size;
1215	max_size = ci->i_wanted_max_size;
1216	ci->i_requested_max_size = max_size;
1217	mtime = inode->i_mtime;
1218	atime = inode->i_atime;
1219	time_warp_seq = ci->i_time_warp_seq;
1220	uid = inode->i_uid;
1221	gid = inode->i_gid;
1222	mode = inode->i_mode;
1223
1224	if (flushing & CEPH_CAP_XATTR_EXCL) {
1225		__ceph_build_xattrs_blob(ci);
1226		xattr_blob = ci->i_xattrs.blob;
1227		xattr_version = ci->i_xattrs.version;
1228	}
1229
1230	spin_unlock(&ci->i_ceph_lock);
1231
1232	ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
1233		op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
1234		size, max_size, &mtime, &atime, time_warp_seq,
1235		uid, gid, mode, xattr_version, xattr_blob,
1236		follows);
1237	if (ret < 0) {
1238		dout("error sending cap msg, must requeue %p\n", inode);
1239		delayed = 1;
1240	}
1241
1242	if (wake)
1243		wake_up_all(&ci->i_cap_wq);
1244
1245	return delayed;
1246}
1247
1248/*
1249 * When a snapshot is taken, clients accumulate dirty metadata on
1250 * inodes with capabilities in ceph_cap_snaps to describe the file
1251 * state at the time the snapshot was taken.  This must be flushed
1252 * asynchronously back to the MDS once sync writes complete and dirty
1253 * data is written out.
1254 *
1255 * Unless @again is true, skip cap_snaps that were already sent to
1256 * the MDS (i.e., during this session).
1257 *
1258 * Called under i_ceph_lock.  Takes s_mutex as needed.
1259 */
1260void __ceph_flush_snaps(struct ceph_inode_info *ci,
1261			struct ceph_mds_session **psession,
1262			int again)
1263		__releases(ci->i_ceph_lock)
1264		__acquires(ci->i_ceph_lock)
1265{
1266	struct inode *inode = &ci->vfs_inode;
1267	int mds;
1268	struct ceph_cap_snap *capsnap;
1269	u32 mseq;
1270	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1271	struct ceph_mds_session *session = NULL; /* if session != NULL, we hold
1272						    session->s_mutex */
1273	u64 next_follows = 0;  /* keep track of how far we've gotten through the
1274			     i_cap_snaps list, and skip these entries next time
1275			     around to avoid an infinite loop */
1276
1277	if (psession)
1278		session = *psession;
1279
1280	dout("__flush_snaps %p\n", inode);
1281retry:
1282	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
1283		/* avoid an infiniute loop after retry */
1284		if (capsnap->follows < next_follows)
1285			continue;
1286		/*
1287		 * we need to wait for sync writes to complete and for dirty
1288		 * pages to be written out.
1289		 */
1290		if (capsnap->dirty_pages || capsnap->writing)
1291			break;
1292
1293		/*
1294		 * if cap writeback already occurred, we should have dropped
1295		 * the capsnap in ceph_put_wrbuffer_cap_refs.
1296		 */
1297		BUG_ON(capsnap->dirty == 0);
1298
1299		/* pick mds, take s_mutex */
1300		if (ci->i_auth_cap == NULL) {
1301			dout("no auth cap (migrating?), doing nothing\n");
1302			goto out;
1303		}
1304
1305		/* only flush each capsnap once */
1306		if (!again && !list_empty(&capsnap->flushing_item)) {
1307			dout("already flushed %p, skipping\n", capsnap);
1308			continue;
1309		}
1310
1311		mds = ci->i_auth_cap->session->s_mds;
1312		mseq = ci->i_auth_cap->mseq;
1313
1314		if (session && session->s_mds != mds) {
1315			dout("oops, wrong session %p mutex\n", session);
1316			mutex_unlock(&session->s_mutex);
1317			ceph_put_mds_session(session);
1318			session = NULL;
1319		}
1320		if (!session) {
1321			spin_unlock(&ci->i_ceph_lock);
1322			mutex_lock(&mdsc->mutex);
1323			session = __ceph_lookup_mds_session(mdsc, mds);
1324			mutex_unlock(&mdsc->mutex);
1325			if (session) {
1326				dout("inverting session/ino locks on %p\n",
1327				     session);
1328				mutex_lock(&session->s_mutex);
1329			}
1330			/*
1331			 * if session == NULL, we raced against a cap
1332			 * deletion or migration.  retry, and we'll
1333			 * get a better @mds value next time.
1334			 */
1335			spin_lock(&ci->i_ceph_lock);
1336			goto retry;
1337		}
1338
1339		capsnap->flush_tid = ++ci->i_cap_flush_last_tid;
1340		atomic_inc(&capsnap->nref);
1341		if (!list_empty(&capsnap->flushing_item))
1342			list_del_init(&capsnap->flushing_item);
1343		list_add_tail(&capsnap->flushing_item,
1344			      &session->s_cap_snaps_flushing);
1345		spin_unlock(&ci->i_ceph_lock);
1346
1347		dout("flush_snaps %p cap_snap %p follows %lld tid %llu\n",
1348		     inode, capsnap, capsnap->follows, capsnap->flush_tid);
1349		send_cap_msg(session, ceph_vino(inode).ino, 0,
1350			     CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
1351			     capsnap->dirty, 0, capsnap->flush_tid, 0, mseq,
1352			     capsnap->size, 0,
1353			     &capsnap->mtime, &capsnap->atime,
1354			     capsnap->time_warp_seq,
1355			     capsnap->uid, capsnap->gid, capsnap->mode,
1356			     capsnap->xattr_version, capsnap->xattr_blob,
1357			     capsnap->follows);
1358
1359		next_follows = capsnap->follows + 1;
1360		ceph_put_cap_snap(capsnap);
1361
1362		spin_lock(&ci->i_ceph_lock);
1363		goto retry;
1364	}
1365
1366	/* we flushed them all; remove this inode from the queue */
1367	spin_lock(&mdsc->snap_flush_lock);
1368	list_del_init(&ci->i_snap_flush_item);
1369	spin_unlock(&mdsc->snap_flush_lock);
1370
1371out:
1372	if (psession)
1373		*psession = session;
1374	else if (session) {
1375		mutex_unlock(&session->s_mutex);
1376		ceph_put_mds_session(session);
1377	}
1378}
1379
1380static void ceph_flush_snaps(struct ceph_inode_info *ci)
1381{
1382	spin_lock(&ci->i_ceph_lock);
1383	__ceph_flush_snaps(ci, NULL, 0);
1384	spin_unlock(&ci->i_ceph_lock);
1385}
1386
1387/*
1388 * Mark caps dirty.  If inode is newly dirty, return the dirty flags.
1389 * Caller is then responsible for calling __mark_inode_dirty with the
1390 * returned flags value.
1391 */
1392int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
1393{
1394	struct ceph_mds_client *mdsc =
1395		ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
1396	struct inode *inode = &ci->vfs_inode;
1397	int was = ci->i_dirty_caps;
1398	int dirty = 0;
1399
1400	dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
1401	     ceph_cap_string(mask), ceph_cap_string(was),
1402	     ceph_cap_string(was | mask));
1403	ci->i_dirty_caps |= mask;
1404	if (was == 0) {
1405		if (!ci->i_head_snapc)
1406			ci->i_head_snapc = ceph_get_snap_context(
1407				ci->i_snap_realm->cached_context);
1408		dout(" inode %p now dirty snapc %p auth cap %p\n",
1409		     &ci->vfs_inode, ci->i_head_snapc, ci->i_auth_cap);
1410		WARN_ON(!ci->i_auth_cap);
1411		BUG_ON(!list_empty(&ci->i_dirty_item));
1412		spin_lock(&mdsc->cap_dirty_lock);
1413		list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
1414		spin_unlock(&mdsc->cap_dirty_lock);
1415		if (ci->i_flushing_caps == 0) {
1416			ihold(inode);
1417			dirty |= I_DIRTY_SYNC;
1418		}
1419	}
1420	BUG_ON(list_empty(&ci->i_dirty_item));
1421	if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
1422	    (mask & CEPH_CAP_FILE_BUFFER))
1423		dirty |= I_DIRTY_DATASYNC;
1424	__cap_delay_requeue(mdsc, ci);
1425	return dirty;
1426}
1427
1428/*
1429 * Add dirty inode to the flushing list.  Assigned a seq number so we
1430 * can wait for caps to flush without starving.
1431 *
1432 * Called under i_ceph_lock.
1433 */
1434static int __mark_caps_flushing(struct inode *inode,
1435				 struct ceph_mds_session *session)
1436{
1437	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1438	struct ceph_inode_info *ci = ceph_inode(inode);
1439	int flushing;
1440
1441	BUG_ON(ci->i_dirty_caps == 0);
1442	BUG_ON(list_empty(&ci->i_dirty_item));
1443
1444	flushing = ci->i_dirty_caps;
1445	dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
1446	     ceph_cap_string(flushing),
1447	     ceph_cap_string(ci->i_flushing_caps),
1448	     ceph_cap_string(ci->i_flushing_caps | flushing));
1449	ci->i_flushing_caps |= flushing;
1450	ci->i_dirty_caps = 0;
1451	dout(" inode %p now !dirty\n", inode);
1452
1453	spin_lock(&mdsc->cap_dirty_lock);
1454	list_del_init(&ci->i_dirty_item);
1455
1456	ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
1457	if (list_empty(&ci->i_flushing_item)) {
1458		list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1459		mdsc->num_cap_flushing++;
1460		dout(" inode %p now flushing seq %lld\n", inode,
1461		     ci->i_cap_flush_seq);
1462	} else {
1463		list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1464		dout(" inode %p now flushing (more) seq %lld\n", inode,
1465		     ci->i_cap_flush_seq);
1466	}
1467	spin_unlock(&mdsc->cap_dirty_lock);
1468
1469	return flushing;
1470}
1471
1472/*
1473 * try to invalidate mapping pages without blocking.
1474 */
1475static int try_nonblocking_invalidate(struct inode *inode)
1476{
1477	struct ceph_inode_info *ci = ceph_inode(inode);
1478	u32 invalidating_gen = ci->i_rdcache_gen;
1479
1480	spin_unlock(&ci->i_ceph_lock);
1481	invalidate_mapping_pages(&inode->i_data, 0, -1);
1482	spin_lock(&ci->i_ceph_lock);
1483
1484	if (inode->i_data.nrpages == 0 &&
1485	    invalidating_gen == ci->i_rdcache_gen) {
1486		/* success. */
1487		dout("try_nonblocking_invalidate %p success\n", inode);
1488		/* save any racing async invalidate some trouble */
1489		ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
1490		return 0;
1491	}
1492	dout("try_nonblocking_invalidate %p failed\n", inode);
1493	return -1;
1494}
1495
1496/*
1497 * Swiss army knife function to examine currently used and wanted
1498 * versus held caps.  Release, flush, ack revoked caps to mds as
1499 * appropriate.
1500 *
1501 *  CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
1502 *    cap release further.
1503 *  CHECK_CAPS_AUTHONLY - we should only check the auth cap
1504 *  CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
1505 *    further delay.
1506 */
1507void ceph_check_caps(struct ceph_inode_info *ci, int flags,
1508		     struct ceph_mds_session *session)
1509{
1510	struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1511	struct ceph_mds_client *mdsc = fsc->mdsc;
1512	struct inode *inode = &ci->vfs_inode;
1513	struct ceph_cap *cap;
1514	int file_wanted, used, cap_used;
1515	int took_snap_rwsem = 0;             /* true if mdsc->snap_rwsem held */
1516	int issued, implemented, want, retain, revoking, flushing = 0;
1517	int mds = -1;   /* keep track of how far we've gone through i_caps list
1518			   to avoid an infinite loop on retry */
1519	struct rb_node *p;
1520	int tried_invalidate = 0;
1521	int delayed = 0, sent = 0, force_requeue = 0, num;
1522	int queue_invalidate = 0;
1523	int is_delayed = flags & CHECK_CAPS_NODELAY;
1524
1525	/* if we are unmounting, flush any unused caps immediately. */
1526	if (mdsc->stopping)
1527		is_delayed = 1;
1528
1529	spin_lock(&ci->i_ceph_lock);
1530
1531	if (ci->i_ceph_flags & CEPH_I_FLUSH)
1532		flags |= CHECK_CAPS_FLUSH;
1533
1534	/* flush snaps first time around only */
1535	if (!list_empty(&ci->i_cap_snaps))
1536		__ceph_flush_snaps(ci, &session, 0);
1537	goto retry_locked;
1538retry:
1539	spin_lock(&ci->i_ceph_lock);
1540retry_locked:
1541	file_wanted = __ceph_caps_file_wanted(ci);
1542	used = __ceph_caps_used(ci);
1543	want = file_wanted | used;
1544	issued = __ceph_caps_issued(ci, &implemented);
1545	revoking = implemented & ~issued;
1546
1547	retain = want | CEPH_CAP_PIN;
1548	if (!mdsc->stopping && inode->i_nlink > 0) {
1549		if (want) {
1550			retain |= CEPH_CAP_ANY;       /* be greedy */
1551		} else {
1552			retain |= CEPH_CAP_ANY_SHARED;
1553			/*
1554			 * keep RD only if we didn't have the file open RW,
1555			 * because then the mds would revoke it anyway to
1556			 * journal max_size=0.
1557			 */
1558			if (ci->i_max_size == 0)
1559				retain |= CEPH_CAP_ANY_RD;
1560		}
1561	}
1562
1563	dout("check_caps %p file_want %s used %s dirty %s flushing %s"
1564	     " issued %s revoking %s retain %s %s%s%s\n", inode,
1565	     ceph_cap_string(file_wanted),
1566	     ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
1567	     ceph_cap_string(ci->i_flushing_caps),
1568	     ceph_cap_string(issued), ceph_cap_string(revoking),
1569	     ceph_cap_string(retain),
1570	     (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
1571	     (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
1572	     (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
1573
1574	/*
1575	 * If we no longer need to hold onto old our caps, and we may
1576	 * have cached pages, but don't want them, then try to invalidate.
1577	 * If we fail, it's because pages are locked.... try again later.
1578	 */
1579	if ((!is_delayed || mdsc->stopping) &&
1580	    ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
1581	    inode->i_data.nrpages &&                 /* have cached pages */
1582	    (file_wanted == 0 ||                     /* no open files */
1583	     (revoking & (CEPH_CAP_FILE_CACHE|
1584			  CEPH_CAP_FILE_LAZYIO))) && /*  or revoking cache */
1585	    !tried_invalidate) {
1586		dout("check_caps trying to invalidate on %p\n", inode);
1587		if (try_nonblocking_invalidate(inode) < 0) {
1588			if (revoking & (CEPH_CAP_FILE_CACHE|
1589					CEPH_CAP_FILE_LAZYIO)) {
1590				dout("check_caps queuing invalidate\n");
1591				queue_invalidate = 1;
1592				ci->i_rdcache_revoking = ci->i_rdcache_gen;
1593			} else {
1594				dout("check_caps failed to invalidate pages\n");
1595				/* we failed to invalidate pages.  check these
1596				   caps again later. */
1597				force_requeue = 1;
1598				__cap_set_timeouts(mdsc, ci);
1599			}
1600		}
1601		tried_invalidate = 1;
1602		goto retry_locked;
1603	}
1604
1605	num = 0;
1606	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
1607		cap = rb_entry(p, struct ceph_cap, ci_node);
1608		num++;
1609
1610		/* avoid looping forever */
1611		if (mds >= cap->mds ||
1612		    ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
1613			continue;
1614
1615		/* NOTE: no side-effects allowed, until we take s_mutex */
1616
1617		cap_used = used;
1618		if (ci->i_auth_cap && cap != ci->i_auth_cap)
1619			cap_used &= ~ci->i_auth_cap->issued;
1620
1621		revoking = cap->implemented & ~cap->issued;
1622		dout(" mds%d cap %p used %s issued %s implemented %s revoking %s\n",
1623		     cap->mds, cap, ceph_cap_string(cap->issued),
1624		     ceph_cap_string(cap_used),
1625		     ceph_cap_string(cap->implemented),
1626		     ceph_cap_string(revoking));
1627
1628		if (cap == ci->i_auth_cap &&
1629		    (cap->issued & CEPH_CAP_FILE_WR)) {
1630			/* request larger max_size from MDS? */
1631			if (ci->i_wanted_max_size > ci->i_max_size &&
1632			    ci->i_wanted_max_size > ci->i_requested_max_size) {
1633				dout("requesting new max_size\n");
1634				goto ack;
1635			}
1636
1637			/* approaching file_max? */
1638			if ((inode->i_size << 1) >= ci->i_max_size &&
1639			    (ci->i_reported_size << 1) < ci->i_max_size) {
1640				dout("i_size approaching max_size\n");
1641				goto ack;
1642			}
1643		}
1644		/* flush anything dirty? */
1645		if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) &&
1646		    ci->i_dirty_caps) {
1647			dout("flushing dirty caps\n");
1648			goto ack;
1649		}
1650
1651		/* completed revocation? going down and there are no caps? */
1652		if (revoking && (revoking & cap_used) == 0) {
1653			dout("completed revocation of %s\n",
1654			     ceph_cap_string(cap->implemented & ~cap->issued));
1655			goto ack;
1656		}
1657
1658		/* want more caps from mds? */
1659		if (want & ~(cap->mds_wanted | cap->issued))
1660			goto ack;
1661
1662		/* things we might delay */
1663		if ((cap->issued & ~retain) == 0 &&
1664		    cap->mds_wanted == want)
1665			continue;     /* nope, all good */
1666
1667		if (is_delayed)
1668			goto ack;
1669
1670		/* delay? */
1671		if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1672		    time_before(jiffies, ci->i_hold_caps_max)) {
1673			dout(" delaying issued %s -> %s, wanted %s -> %s\n",
1674			     ceph_cap_string(cap->issued),
1675			     ceph_cap_string(cap->issued & retain),
1676			     ceph_cap_string(cap->mds_wanted),
1677			     ceph_cap_string(want));
1678			delayed++;
1679			continue;
1680		}
1681
1682ack:
1683		if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1684			dout(" skipping %p I_NOFLUSH set\n", inode);
1685			continue;
1686		}
1687
1688		if (session && session != cap->session) {
1689			dout("oops, wrong session %p mutex\n", session);
1690			mutex_unlock(&session->s_mutex);
1691			session = NULL;
1692		}
1693		if (!session) {
1694			session = cap->session;
1695			if (mutex_trylock(&session->s_mutex) == 0) {
1696				dout("inverting session/ino locks on %p\n",
1697				     session);
1698				spin_unlock(&ci->i_ceph_lock);
1699				if (took_snap_rwsem) {
1700					up_read(&mdsc->snap_rwsem);
1701					took_snap_rwsem = 0;
1702				}
1703				mutex_lock(&session->s_mutex);
1704				goto retry;
1705			}
1706		}
1707		/* take snap_rwsem after session mutex */
1708		if (!took_snap_rwsem) {
1709			if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
1710				dout("inverting snap/in locks on %p\n",
1711				     inode);
1712				spin_unlock(&ci->i_ceph_lock);
1713				down_read(&mdsc->snap_rwsem);
1714				took_snap_rwsem = 1;
1715				goto retry;
1716			}
1717			took_snap_rwsem = 1;
1718		}
1719
1720		if (cap == ci->i_auth_cap && ci->i_dirty_caps)
1721			flushing = __mark_caps_flushing(inode, session);
1722		else
1723			flushing = 0;
1724
1725		mds = cap->mds;  /* remember mds, so we don't repeat */
1726		sent++;
1727
1728		/* __send_cap drops i_ceph_lock */
1729		delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, cap_used,
1730				      want, retain, flushing, NULL);
1731		goto retry; /* retake i_ceph_lock and restart our cap scan. */
1732	}
1733
1734	/*
1735	 * Reschedule delayed caps release if we delayed anything,
1736	 * otherwise cancel.
1737	 */
1738	if (delayed && is_delayed)
1739		force_requeue = 1;   /* __send_cap delayed release; requeue */
1740	if (!delayed && !is_delayed)
1741		__cap_delay_cancel(mdsc, ci);
1742	else if (!is_delayed || force_requeue)
1743		__cap_delay_requeue(mdsc, ci);
1744
1745	spin_unlock(&ci->i_ceph_lock);
1746
1747	if (queue_invalidate)
1748		ceph_queue_invalidate(inode);
1749
1750	if (session)
1751		mutex_unlock(&session->s_mutex);
1752	if (took_snap_rwsem)
1753		up_read(&mdsc->snap_rwsem);
1754}
1755
1756/*
1757 * Try to flush dirty caps back to the auth mds.
1758 */
1759static int try_flush_caps(struct inode *inode, unsigned *flush_tid)
 
1760{
1761	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1762	struct ceph_inode_info *ci = ceph_inode(inode);
 
1763	int flushing = 0;
1764	struct ceph_mds_session *session = NULL;
1765
1766retry:
1767	spin_lock(&ci->i_ceph_lock);
1768	if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1769		dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
1770		goto out;
1771	}
1772	if (ci->i_dirty_caps && ci->i_auth_cap) {
1773		struct ceph_cap *cap = ci->i_auth_cap;
1774		int used = __ceph_caps_used(ci);
1775		int want = __ceph_caps_wanted(ci);
1776		int delayed;
1777
1778		if (!session || session != cap->session) {
1779			spin_unlock(&ci->i_ceph_lock);
1780			if (session)
1781				mutex_unlock(&session->s_mutex);
1782			session = cap->session;
1783			mutex_lock(&session->s_mutex);
1784			goto retry;
1785		}
 
1786		if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
1787			goto out;
1788
1789		flushing = __mark_caps_flushing(inode, session);
1790
1791		/* __send_cap drops i_ceph_lock */
1792		delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
1793				     cap->issued | cap->implemented, flushing,
1794				     flush_tid);
1795		if (!delayed)
1796			goto out_unlocked;
1797
1798		spin_lock(&ci->i_ceph_lock);
1799		__cap_delay_requeue(mdsc, ci);
1800	}
1801out:
1802	spin_unlock(&ci->i_ceph_lock);
1803out_unlocked:
1804	if (session)
1805		mutex_unlock(&session->s_mutex);
1806	return flushing;
1807}
1808
1809/*
1810 * Return true if we've flushed caps through the given flush_tid.
1811 */
1812static int caps_are_flushed(struct inode *inode, unsigned tid)
1813{
1814	struct ceph_inode_info *ci = ceph_inode(inode);
1815	int i, ret = 1;
1816
1817	spin_lock(&ci->i_ceph_lock);
1818	for (i = 0; i < CEPH_CAP_BITS; i++)
1819		if ((ci->i_flushing_caps & (1 << i)) &&
1820		    ci->i_cap_flush_tid[i] <= tid) {
1821			/* still flushing this bit */
1822			ret = 0;
1823			break;
1824		}
1825	spin_unlock(&ci->i_ceph_lock);
1826	return ret;
1827}
1828
1829/*
1830 * Wait on any unsafe replies for the given inode.  First wait on the
1831 * newest request, and make that the upper bound.  Then, if there are
1832 * more requests, keep waiting on the oldest as long as it is still older
1833 * than the original request.
1834 */
1835static void sync_write_wait(struct inode *inode)
1836{
1837	struct ceph_inode_info *ci = ceph_inode(inode);
1838	struct list_head *head = &ci->i_unsafe_writes;
1839	struct ceph_osd_request *req;
1840	u64 last_tid;
1841
1842	spin_lock(&ci->i_unsafe_lock);
1843	if (list_empty(head))
1844		goto out;
1845
1846	/* set upper bound as _last_ entry in chain */
1847	req = list_entry(head->prev, struct ceph_osd_request,
1848			 r_unsafe_item);
1849	last_tid = req->r_tid;
1850
1851	do {
1852		ceph_osdc_get_request(req);
1853		spin_unlock(&ci->i_unsafe_lock);
1854		dout("sync_write_wait on tid %llu (until %llu)\n",
1855		     req->r_tid, last_tid);
1856		wait_for_completion(&req->r_safe_completion);
1857		spin_lock(&ci->i_unsafe_lock);
1858		ceph_osdc_put_request(req);
1859
1860		/*
1861		 * from here on look at first entry in chain, since we
1862		 * only want to wait for anything older than last_tid
1863		 */
1864		if (list_empty(head))
1865			break;
1866		req = list_entry(head->next, struct ceph_osd_request,
1867				 r_unsafe_item);
1868	} while (req->r_tid < last_tid);
1869out:
1870	spin_unlock(&ci->i_unsafe_lock);
1871}
1872
1873int ceph_fsync(struct file *file, loff_t start, loff_t end, int datasync)
1874{
1875	struct inode *inode = file->f_mapping->host;
1876	struct ceph_inode_info *ci = ceph_inode(inode);
1877	unsigned flush_tid;
1878	int ret;
1879	int dirty;
1880
1881	dout("fsync %p%s\n", inode, datasync ? " datasync" : "");
1882	sync_write_wait(inode);
1883
1884	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1885	if (ret < 0)
1886		return ret;
1887	mutex_lock(&inode->i_mutex);
1888
1889	dirty = try_flush_caps(inode, &flush_tid);
1890	dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
1891
1892	/*
1893	 * only wait on non-file metadata writeback (the mds
1894	 * can recover size and mtime, so we don't need to
1895	 * wait for that)
1896	 */
1897	if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
1898		dout("fsync waiting for flush_tid %u\n", flush_tid);
1899		ret = wait_event_interruptible(ci->i_cap_wq,
1900				       caps_are_flushed(inode, flush_tid));
1901	}
1902
1903	dout("fsync %p%s done\n", inode, datasync ? " datasync" : "");
1904	mutex_unlock(&inode->i_mutex);
1905	return ret;
1906}
1907
1908/*
1909 * Flush any dirty caps back to the mds.  If we aren't asked to wait,
1910 * queue inode for flush but don't do so immediately, because we can
1911 * get by with fewer MDS messages if we wait for data writeback to
1912 * complete first.
1913 */
1914int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
1915{
1916	struct ceph_inode_info *ci = ceph_inode(inode);
1917	unsigned flush_tid;
1918	int err = 0;
1919	int dirty;
1920	int wait = wbc->sync_mode == WB_SYNC_ALL;
1921
1922	dout("write_inode %p wait=%d\n", inode, wait);
1923	if (wait) {
1924		dirty = try_flush_caps(inode, &flush_tid);
1925		if (dirty)
1926			err = wait_event_interruptible(ci->i_cap_wq,
1927				       caps_are_flushed(inode, flush_tid));
1928	} else {
1929		struct ceph_mds_client *mdsc =
1930			ceph_sb_to_client(inode->i_sb)->mdsc;
1931
1932		spin_lock(&ci->i_ceph_lock);
1933		if (__ceph_caps_dirty(ci))
1934			__cap_delay_requeue_front(mdsc, ci);
1935		spin_unlock(&ci->i_ceph_lock);
1936	}
1937	return err;
1938}
1939
1940/*
1941 * After a recovering MDS goes active, we need to resend any caps
1942 * we were flushing.
1943 *
1944 * Caller holds session->s_mutex.
1945 */
1946static void kick_flushing_capsnaps(struct ceph_mds_client *mdsc,
1947				   struct ceph_mds_session *session)
1948{
1949	struct ceph_cap_snap *capsnap;
1950
1951	dout("kick_flushing_capsnaps mds%d\n", session->s_mds);
1952	list_for_each_entry(capsnap, &session->s_cap_snaps_flushing,
1953			    flushing_item) {
1954		struct ceph_inode_info *ci = capsnap->ci;
1955		struct inode *inode = &ci->vfs_inode;
1956		struct ceph_cap *cap;
1957
1958		spin_lock(&ci->i_ceph_lock);
1959		cap = ci->i_auth_cap;
1960		if (cap && cap->session == session) {
1961			dout("kick_flushing_caps %p cap %p capsnap %p\n", inode,
1962			     cap, capsnap);
1963			__ceph_flush_snaps(ci, &session, 1);
1964		} else {
1965			pr_err("%p auth cap %p not mds%d ???\n", inode,
1966			       cap, session->s_mds);
1967		}
1968		spin_unlock(&ci->i_ceph_lock);
1969	}
1970}
1971
1972void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
1973			     struct ceph_mds_session *session)
1974{
1975	struct ceph_inode_info *ci;
1976
1977	kick_flushing_capsnaps(mdsc, session);
1978
1979	dout("kick_flushing_caps mds%d\n", session->s_mds);
1980	list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
1981		struct inode *inode = &ci->vfs_inode;
1982		struct ceph_cap *cap;
1983		int delayed = 0;
1984
1985		spin_lock(&ci->i_ceph_lock);
1986		cap = ci->i_auth_cap;
1987		if (cap && cap->session == session) {
1988			dout("kick_flushing_caps %p cap %p %s\n", inode,
1989			     cap, ceph_cap_string(ci->i_flushing_caps));
1990			delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
1991					     __ceph_caps_used(ci),
1992					     __ceph_caps_wanted(ci),
1993					     cap->issued | cap->implemented,
1994					     ci->i_flushing_caps, NULL);
1995			if (delayed) {
1996				spin_lock(&ci->i_ceph_lock);
1997				__cap_delay_requeue(mdsc, ci);
1998				spin_unlock(&ci->i_ceph_lock);
1999			}
2000		} else {
2001			pr_err("%p auth cap %p not mds%d ???\n", inode,
2002			       cap, session->s_mds);
2003			spin_unlock(&ci->i_ceph_lock);
2004		}
2005	}
2006}
2007
2008static void kick_flushing_inode_caps(struct ceph_mds_client *mdsc,
2009				     struct ceph_mds_session *session,
2010				     struct inode *inode)
2011{
2012	struct ceph_inode_info *ci = ceph_inode(inode);
2013	struct ceph_cap *cap;
2014	int delayed = 0;
2015
2016	spin_lock(&ci->i_ceph_lock);
2017	cap = ci->i_auth_cap;
2018	dout("kick_flushing_inode_caps %p flushing %s flush_seq %lld\n", inode,
2019	     ceph_cap_string(ci->i_flushing_caps), ci->i_cap_flush_seq);
2020
2021	__ceph_flush_snaps(ci, &session, 1);
2022
2023	if (ci->i_flushing_caps) {
2024		spin_lock(&mdsc->cap_dirty_lock);
2025		list_move_tail(&ci->i_flushing_item,
2026			       &cap->session->s_cap_flushing);
2027		spin_unlock(&mdsc->cap_dirty_lock);
2028
2029		delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
2030				     __ceph_caps_used(ci),
2031				     __ceph_caps_wanted(ci),
2032				     cap->issued | cap->implemented,
2033				     ci->i_flushing_caps, NULL);
2034		if (delayed) {
2035			spin_lock(&ci->i_ceph_lock);
2036			__cap_delay_requeue(mdsc, ci);
2037			spin_unlock(&ci->i_ceph_lock);
2038		}
2039	} else {
2040		spin_unlock(&ci->i_ceph_lock);
2041	}
2042}
2043
2044
2045/*
2046 * Take references to capabilities we hold, so that we don't release
2047 * them to the MDS prematurely.
2048 *
2049 * Protected by i_ceph_lock.
2050 */
2051static void __take_cap_refs(struct ceph_inode_info *ci, int got)
2052{
2053	if (got & CEPH_CAP_PIN)
2054		ci->i_pin_ref++;
2055	if (got & CEPH_CAP_FILE_RD)
2056		ci->i_rd_ref++;
2057	if (got & CEPH_CAP_FILE_CACHE)
2058		ci->i_rdcache_ref++;
2059	if (got & CEPH_CAP_FILE_WR)
2060		ci->i_wr_ref++;
2061	if (got & CEPH_CAP_FILE_BUFFER) {
2062		if (ci->i_wb_ref == 0)
2063			ihold(&ci->vfs_inode);
2064		ci->i_wb_ref++;
2065		dout("__take_cap_refs %p wb %d -> %d (?)\n",
2066		     &ci->vfs_inode, ci->i_wb_ref-1, ci->i_wb_ref);
2067	}
2068}
2069
2070/*
2071 * Try to grab cap references.  Specify those refs we @want, and the
2072 * minimal set we @need.  Also include the larger offset we are writing
2073 * to (when applicable), and check against max_size here as well.
2074 * Note that caller is responsible for ensuring max_size increases are
2075 * requested from the MDS.
2076 */
2077static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
2078			    int *got, loff_t endoff, int *check_max, int *err)
2079{
2080	struct inode *inode = &ci->vfs_inode;
2081	int ret = 0;
2082	int have, implemented;
2083	int file_wanted;
2084
2085	dout("get_cap_refs %p need %s want %s\n", inode,
2086	     ceph_cap_string(need), ceph_cap_string(want));
2087	spin_lock(&ci->i_ceph_lock);
2088
2089	/* make sure file is actually open */
2090	file_wanted = __ceph_caps_file_wanted(ci);
2091	if ((file_wanted & need) == 0) {
2092		dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
2093		     ceph_cap_string(need), ceph_cap_string(file_wanted));
2094		*err = -EBADF;
2095		ret = 1;
2096		goto out;
2097	}
2098
2099	/* finish pending truncate */
2100	while (ci->i_truncate_pending) {
2101		spin_unlock(&ci->i_ceph_lock);
2102		__ceph_do_pending_vmtruncate(inode);
2103		spin_lock(&ci->i_ceph_lock);
2104	}
2105
2106	have = __ceph_caps_issued(ci, &implemented);
2107
2108	if (have & need & CEPH_CAP_FILE_WR) {
2109		if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
2110			dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
2111			     inode, endoff, ci->i_max_size);
2112			if (endoff > ci->i_requested_max_size) {
2113				*check_max = 1;
2114				ret = 1;
2115			}
2116			goto out;
2117		}
2118		/*
2119		 * If a sync write is in progress, we must wait, so that we
2120		 * can get a final snapshot value for size+mtime.
2121		 */
2122		if (__ceph_have_pending_cap_snap(ci)) {
2123			dout("get_cap_refs %p cap_snap_pending\n", inode);
2124			goto out;
2125		}
2126	}
 
 
 
 
 
 
 
2127
2128	if ((have & need) == need) {
2129		/*
2130		 * Look at (implemented & ~have & not) so that we keep waiting
2131		 * on transition from wanted -> needed caps.  This is needed
2132		 * for WRBUFFER|WR -> WR to avoid a new WR sync write from
2133		 * going before a prior buffered writeback happens.
2134		 */
2135		int not = want & ~(have & need);
2136		int revoking = implemented & ~have;
2137		dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
2138		     inode, ceph_cap_string(have), ceph_cap_string(not),
2139		     ceph_cap_string(revoking));
2140		if ((revoking & not) == 0) {
2141			*got = need | (have & want);
2142			__take_cap_refs(ci, *got);
2143			ret = 1;
2144		}
2145	} else {
2146		dout("get_cap_refs %p have %s needed %s\n", inode,
2147		     ceph_cap_string(have), ceph_cap_string(need));
2148	}
2149out:
2150	spin_unlock(&ci->i_ceph_lock);
2151	dout("get_cap_refs %p ret %d got %s\n", inode,
2152	     ret, ceph_cap_string(*got));
2153	return ret;
2154}
2155
2156/*
2157 * Check the offset we are writing up to against our current
2158 * max_size.  If necessary, tell the MDS we want to write to
2159 * a larger offset.
2160 */
2161static void check_max_size(struct inode *inode, loff_t endoff)
2162{
2163	struct ceph_inode_info *ci = ceph_inode(inode);
2164	int check = 0;
2165
2166	/* do we need to explicitly request a larger max_size? */
2167	spin_lock(&ci->i_ceph_lock);
2168	if (endoff >= ci->i_max_size && endoff > ci->i_wanted_max_size) {
 
 
2169		dout("write %p at large endoff %llu, req max_size\n",
2170		     inode, endoff);
2171		ci->i_wanted_max_size = endoff;
2172	}
2173	/* duplicate ceph_check_caps()'s logic */
2174	if (ci->i_auth_cap &&
2175	    (ci->i_auth_cap->issued & CEPH_CAP_FILE_WR) &&
2176	    ci->i_wanted_max_size > ci->i_max_size &&
2177	    ci->i_wanted_max_size > ci->i_requested_max_size)
2178		check = 1;
 
2179	spin_unlock(&ci->i_ceph_lock);
2180	if (check)
2181		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2182}
2183
2184/*
2185 * Wait for caps, and take cap references.  If we can't get a WR cap
2186 * due to a small max_size, make sure we check_max_size (and possibly
2187 * ask the mds) so we don't get hung up indefinitely.
2188 */
2189int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got,
2190		  loff_t endoff)
2191{
2192	int check_max, ret, err;
2193
2194retry:
2195	if (endoff > 0)
2196		check_max_size(&ci->vfs_inode, endoff);
2197	check_max = 0;
2198	err = 0;
2199	ret = wait_event_interruptible(ci->i_cap_wq,
2200				       try_get_cap_refs(ci, need, want,
2201							got, endoff,
2202							&check_max, &err));
2203	if (err)
2204		ret = err;
2205	if (check_max)
2206		goto retry;
2207	return ret;
2208}
2209
2210/*
2211 * Take cap refs.  Caller must already know we hold at least one ref
2212 * on the caps in question or we don't know this is safe.
2213 */
2214void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
2215{
2216	spin_lock(&ci->i_ceph_lock);
2217	__take_cap_refs(ci, caps);
2218	spin_unlock(&ci->i_ceph_lock);
2219}
2220
2221/*
2222 * Release cap refs.
2223 *
2224 * If we released the last ref on any given cap, call ceph_check_caps
2225 * to release (or schedule a release).
2226 *
2227 * If we are releasing a WR cap (from a sync write), finalize any affected
2228 * cap_snap, and wake up any waiters.
2229 */
2230void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
2231{
2232	struct inode *inode = &ci->vfs_inode;
2233	int last = 0, put = 0, flushsnaps = 0, wake = 0;
2234	struct ceph_cap_snap *capsnap;
2235
2236	spin_lock(&ci->i_ceph_lock);
2237	if (had & CEPH_CAP_PIN)
2238		--ci->i_pin_ref;
2239	if (had & CEPH_CAP_FILE_RD)
2240		if (--ci->i_rd_ref == 0)
2241			last++;
2242	if (had & CEPH_CAP_FILE_CACHE)
2243		if (--ci->i_rdcache_ref == 0)
2244			last++;
2245	if (had & CEPH_CAP_FILE_BUFFER) {
2246		if (--ci->i_wb_ref == 0) {
2247			last++;
2248			put++;
2249		}
2250		dout("put_cap_refs %p wb %d -> %d (?)\n",
2251		     inode, ci->i_wb_ref+1, ci->i_wb_ref);
2252	}
2253	if (had & CEPH_CAP_FILE_WR)
2254		if (--ci->i_wr_ref == 0) {
2255			last++;
2256			if (!list_empty(&ci->i_cap_snaps)) {
2257				capsnap = list_first_entry(&ci->i_cap_snaps,
2258						     struct ceph_cap_snap,
2259						     ci_item);
2260				if (capsnap->writing) {
2261					capsnap->writing = 0;
2262					flushsnaps =
2263						__ceph_finish_cap_snap(ci,
2264								       capsnap);
2265					wake = 1;
2266				}
2267			}
2268		}
2269	spin_unlock(&ci->i_ceph_lock);
2270
2271	dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
2272	     last ? " last" : "", put ? " put" : "");
2273
2274	if (last && !flushsnaps)
2275		ceph_check_caps(ci, 0, NULL);
2276	else if (flushsnaps)
2277		ceph_flush_snaps(ci);
2278	if (wake)
2279		wake_up_all(&ci->i_cap_wq);
2280	if (put)
2281		iput(inode);
2282}
2283
2284/*
2285 * Release @nr WRBUFFER refs on dirty pages for the given @snapc snap
2286 * context.  Adjust per-snap dirty page accounting as appropriate.
2287 * Once all dirty data for a cap_snap is flushed, flush snapped file
2288 * metadata back to the MDS.  If we dropped the last ref, call
2289 * ceph_check_caps.
2290 */
2291void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
2292				struct ceph_snap_context *snapc)
2293{
2294	struct inode *inode = &ci->vfs_inode;
2295	int last = 0;
2296	int complete_capsnap = 0;
2297	int drop_capsnap = 0;
2298	int found = 0;
2299	struct ceph_cap_snap *capsnap = NULL;
2300
2301	spin_lock(&ci->i_ceph_lock);
2302	ci->i_wrbuffer_ref -= nr;
2303	last = !ci->i_wrbuffer_ref;
2304
2305	if (ci->i_head_snapc == snapc) {
2306		ci->i_wrbuffer_ref_head -= nr;
2307		if (ci->i_wrbuffer_ref_head == 0 &&
2308		    ci->i_dirty_caps == 0 && ci->i_flushing_caps == 0) {
2309			BUG_ON(!ci->i_head_snapc);
2310			ceph_put_snap_context(ci->i_head_snapc);
2311			ci->i_head_snapc = NULL;
2312		}
2313		dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n",
2314		     inode,
2315		     ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr,
2316		     ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
2317		     last ? " LAST" : "");
2318	} else {
2319		list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2320			if (capsnap->context == snapc) {
2321				found = 1;
2322				break;
2323			}
2324		}
2325		BUG_ON(!found);
2326		capsnap->dirty_pages -= nr;
2327		if (capsnap->dirty_pages == 0) {
2328			complete_capsnap = 1;
2329			if (capsnap->dirty == 0)
2330				/* cap writeback completed before we created
2331				 * the cap_snap; no FLUSHSNAP is needed */
2332				drop_capsnap = 1;
2333		}
2334		dout("put_wrbuffer_cap_refs on %p cap_snap %p "
2335		     " snap %lld %d/%d -> %d/%d %s%s%s\n",
2336		     inode, capsnap, capsnap->context->seq,
2337		     ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr,
2338		     ci->i_wrbuffer_ref, capsnap->dirty_pages,
2339		     last ? " (wrbuffer last)" : "",
2340		     complete_capsnap ? " (complete capsnap)" : "",
2341		     drop_capsnap ? " (drop capsnap)" : "");
2342		if (drop_capsnap) {
2343			ceph_put_snap_context(capsnap->context);
2344			list_del(&capsnap->ci_item);
2345			list_del(&capsnap->flushing_item);
2346			ceph_put_cap_snap(capsnap);
2347		}
2348	}
2349
2350	spin_unlock(&ci->i_ceph_lock);
2351
2352	if (last) {
2353		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2354		iput(inode);
2355	} else if (complete_capsnap) {
2356		ceph_flush_snaps(ci);
2357		wake_up_all(&ci->i_cap_wq);
2358	}
2359	if (drop_capsnap)
2360		iput(inode);
2361}
2362
2363/*
2364 * Invalidate unlinked inode's aliases, so we can drop the inode ASAP.
2365 */
2366static void invalidate_aliases(struct inode *inode)
2367{
2368	struct dentry *dn, *prev = NULL;
2369
2370	dout("invalidate_aliases inode %p\n", inode);
2371	d_prune_aliases(inode);
2372	/*
2373	 * For non-directory inode, d_find_alias() only returns
2374	 * hashed dentry. After calling d_invalidate(), the
2375	 * dentry becomes unhashed.
2376	 *
2377	 * For directory inode, d_find_alias() can return
2378	 * unhashed dentry. But directory inode should have
2379	 * one alias at most.
2380	 */
2381	while ((dn = d_find_alias(inode))) {
2382		if (dn == prev) {
2383			dput(dn);
2384			break;
2385		}
2386		d_invalidate(dn);
2387		if (prev)
2388			dput(prev);
2389		prev = dn;
2390	}
2391	if (prev)
2392		dput(prev);
2393}
2394
2395/*
2396 * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
2397 * actually be a revocation if it specifies a smaller cap set.)
2398 *
2399 * caller holds s_mutex and i_ceph_lock, we drop both.
2400 *
2401 * return value:
2402 *  0 - ok
2403 *  1 - check_caps on auth cap only (writeback)
2404 *  2 - check_caps (ack revoke)
2405 */
2406static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
2407			     struct ceph_mds_session *session,
2408			     struct ceph_cap *cap,
2409			     struct ceph_buffer *xattr_buf)
2410		__releases(ci->i_ceph_lock)
2411{
2412	struct ceph_inode_info *ci = ceph_inode(inode);
2413	int mds = session->s_mds;
2414	int seq = le32_to_cpu(grant->seq);
2415	int newcaps = le32_to_cpu(grant->caps);
2416	int issued, implemented, used, wanted, dirty;
2417	u64 size = le64_to_cpu(grant->size);
2418	u64 max_size = le64_to_cpu(grant->max_size);
2419	struct timespec mtime, atime, ctime;
2420	int check_caps = 0;
2421	int wake = 0;
2422	int writeback = 0;
 
2423	int queue_invalidate = 0;
2424	int deleted_inode = 0;
2425	int queue_revalidate = 0;
2426
2427	dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
2428	     inode, cap, mds, seq, ceph_cap_string(newcaps));
2429	dout(" size %llu max_size %llu, i_size %llu\n", size, max_size,
2430		inode->i_size);
2431
2432
2433	/*
2434	 * auth mds of the inode changed. we received the cap export message,
2435	 * but still haven't received the cap import message. handle_cap_export
2436	 * updated the new auth MDS' cap.
2437	 *
2438	 * "ceph_seq_cmp(seq, cap->seq) <= 0" means we are processing a message
2439	 * that was sent before the cap import message. So don't remove caps.
2440	 */
2441	if (ceph_seq_cmp(seq, cap->seq) <= 0) {
2442		WARN_ON(cap != ci->i_auth_cap);
2443		WARN_ON(cap->cap_id != le64_to_cpu(grant->cap_id));
2444		seq = cap->seq;
2445		newcaps |= cap->issued;
2446	}
2447
2448	/*
2449	 * If CACHE is being revoked, and we have no dirty buffers,
2450	 * try to invalidate (once).  (If there are dirty buffers, we
2451	 * will invalidate _after_ writeback.)
2452	 */
2453	if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
2454	    (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
2455	    !ci->i_wrbuffer_ref) {
2456		if (try_nonblocking_invalidate(inode)) {
 
 
2457			/* there were locked pages.. invalidate later
2458			   in a separate thread. */
2459			if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
2460				queue_invalidate = 1;
2461				ci->i_rdcache_revoking = ci->i_rdcache_gen;
2462			}
2463		}
2464
2465		ceph_fscache_invalidate(inode);
2466	}
2467
2468	/* side effects now are allowed */
2469
2470	issued = __ceph_caps_issued(ci, &implemented);
2471	issued |= implemented | __ceph_caps_dirty(ci);
2472
2473	cap->cap_gen = session->s_cap_gen;
2474	cap->seq = seq;
2475
2476	__check_cap_issue(ci, cap, newcaps);
2477
2478	if ((issued & CEPH_CAP_AUTH_EXCL) == 0) {
2479		inode->i_mode = le32_to_cpu(grant->mode);
2480		inode->i_uid = make_kuid(&init_user_ns, le32_to_cpu(grant->uid));
2481		inode->i_gid = make_kgid(&init_user_ns, le32_to_cpu(grant->gid));
2482		dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
2483		     from_kuid(&init_user_ns, inode->i_uid),
2484		     from_kgid(&init_user_ns, inode->i_gid));
2485	}
2486
2487	if ((issued & CEPH_CAP_LINK_EXCL) == 0) {
2488		set_nlink(inode, le32_to_cpu(grant->nlink));
2489		if (inode->i_nlink == 0 &&
2490		    (newcaps & (CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL)))
2491			deleted_inode = 1;
2492	}
2493
2494	if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
2495		int len = le32_to_cpu(grant->xattr_len);
2496		u64 version = le64_to_cpu(grant->xattr_version);
2497
2498		if (version > ci->i_xattrs.version) {
2499			dout(" got new xattrs v%llu on %p len %d\n",
2500			     version, inode, len);
2501			if (ci->i_xattrs.blob)
2502				ceph_buffer_put(ci->i_xattrs.blob);
2503			ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
2504			ci->i_xattrs.version = version;
2505			ceph_forget_all_cached_acls(inode);
2506		}
2507	}
2508
2509	/* Do we need to revalidate our fscache cookie. Don't bother on the
2510	 * first cache cap as we already validate at cookie creation time. */
2511	if ((issued & CEPH_CAP_FILE_CACHE) && ci->i_rdcache_gen > 1)
2512		queue_revalidate = 1;
2513
2514	/* size/ctime/mtime/atime? */
2515	ceph_fill_file_size(inode, issued,
2516			    le32_to_cpu(grant->truncate_seq),
2517			    le64_to_cpu(grant->truncate_size), size);
2518	ceph_decode_timespec(&mtime, &grant->mtime);
2519	ceph_decode_timespec(&atime, &grant->atime);
2520	ceph_decode_timespec(&ctime, &grant->ctime);
2521	ceph_fill_file_time(inode, issued,
2522			    le32_to_cpu(grant->time_warp_seq), &ctime, &mtime,
2523			    &atime);
2524
2525
2526	/* file layout may have changed */
2527	ci->i_layout = grant->layout;
2528
2529	/* max size increase? */
2530	if (ci->i_auth_cap == cap && max_size != ci->i_max_size) {
2531		dout("max_size %lld -> %llu\n", ci->i_max_size, max_size);
2532		ci->i_max_size = max_size;
2533		if (max_size >= ci->i_wanted_max_size) {
2534			ci->i_wanted_max_size = 0;  /* reset */
2535			ci->i_requested_max_size = 0;
2536		}
2537		wake = 1;
2538	}
2539
2540	/* check cap bits */
2541	wanted = __ceph_caps_wanted(ci);
2542	used = __ceph_caps_used(ci);
2543	dirty = __ceph_caps_dirty(ci);
2544	dout(" my wanted = %s, used = %s, dirty %s\n",
2545	     ceph_cap_string(wanted),
2546	     ceph_cap_string(used),
2547	     ceph_cap_string(dirty));
2548	if (wanted != le32_to_cpu(grant->wanted)) {
2549		dout("mds wanted %s -> %s\n",
2550		     ceph_cap_string(le32_to_cpu(grant->wanted)),
2551		     ceph_cap_string(wanted));
2552		/* imported cap may not have correct mds_wanted */
2553		if (le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT)
2554			check_caps = 1;
2555	}
2556
 
 
 
 
 
2557	/* revocation, grant, or no-op? */
2558	if (cap->issued & ~newcaps) {
2559		int revoking = cap->issued & ~newcaps;
2560
2561		dout("revocation: %s -> %s (revoking %s)\n",
2562		     ceph_cap_string(cap->issued),
2563		     ceph_cap_string(newcaps),
2564		     ceph_cap_string(revoking));
2565		if (revoking & used & CEPH_CAP_FILE_BUFFER)
2566			writeback = 1;  /* initiate writeback; will delay ack */
2567		else if (revoking == CEPH_CAP_FILE_CACHE &&
2568			 (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
2569			 queue_invalidate)
2570			; /* do nothing yet, invalidation will be queued */
2571		else if (cap == ci->i_auth_cap)
2572			check_caps = 1; /* check auth cap only */
2573		else
2574			check_caps = 2; /* check all caps */
2575		cap->issued = newcaps;
2576		cap->implemented |= newcaps;
2577	} else if (cap->issued == newcaps) {
2578		dout("caps unchanged: %s -> %s\n",
2579		     ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
2580	} else {
2581		dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
2582		     ceph_cap_string(newcaps));
2583		/* non-auth MDS is revoking the newly grant caps ? */
2584		if (cap == ci->i_auth_cap &&
2585		    __ceph_caps_revoking_other(ci, cap, newcaps))
2586		    check_caps = 2;
2587
2588		cap->issued = newcaps;
2589		cap->implemented |= newcaps; /* add bits only, to
2590					      * avoid stepping on a
2591					      * pending revocation */
2592		wake = 1;
2593	}
2594	BUG_ON(cap->issued & ~cap->implemented);
2595
2596	spin_unlock(&ci->i_ceph_lock);
2597
2598	if (writeback)
2599		/*
2600		 * queue inode for writeback: we can't actually call
2601		 * filemap_write_and_wait, etc. from message handler
2602		 * context.
2603		 */
2604		ceph_queue_writeback(inode);
2605	if (queue_invalidate)
2606		ceph_queue_invalidate(inode);
2607	if (deleted_inode)
2608		invalidate_aliases(inode);
2609	if (queue_revalidate)
2610		ceph_queue_revalidate(inode);
2611	if (wake)
2612		wake_up_all(&ci->i_cap_wq);
2613
2614	if (check_caps == 1)
2615		ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
2616				session);
2617	else if (check_caps == 2)
2618		ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
2619	else
2620		mutex_unlock(&session->s_mutex);
2621}
2622
2623/*
2624 * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
2625 * MDS has been safely committed.
2626 */
2627static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
2628				 struct ceph_mds_caps *m,
2629				 struct ceph_mds_session *session,
2630				 struct ceph_cap *cap)
2631	__releases(ci->i_ceph_lock)
2632{
2633	struct ceph_inode_info *ci = ceph_inode(inode);
2634	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
2635	unsigned seq = le32_to_cpu(m->seq);
2636	int dirty = le32_to_cpu(m->dirty);
2637	int cleaned = 0;
2638	int drop = 0;
2639	int i;
2640
2641	for (i = 0; i < CEPH_CAP_BITS; i++)
2642		if ((dirty & (1 << i)) &&
2643		    flush_tid == ci->i_cap_flush_tid[i])
2644			cleaned |= 1 << i;
2645
2646	dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s,"
2647	     " flushing %s -> %s\n",
2648	     inode, session->s_mds, seq, ceph_cap_string(dirty),
2649	     ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
2650	     ceph_cap_string(ci->i_flushing_caps & ~cleaned));
2651
2652	if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
2653		goto out;
2654
2655	ci->i_flushing_caps &= ~cleaned;
2656
2657	spin_lock(&mdsc->cap_dirty_lock);
2658	if (ci->i_flushing_caps == 0) {
2659		list_del_init(&ci->i_flushing_item);
2660		if (!list_empty(&session->s_cap_flushing))
2661			dout(" mds%d still flushing cap on %p\n",
2662			     session->s_mds,
2663			     &list_entry(session->s_cap_flushing.next,
2664					 struct ceph_inode_info,
2665					 i_flushing_item)->vfs_inode);
2666		mdsc->num_cap_flushing--;
2667		wake_up_all(&mdsc->cap_flushing_wq);
2668		dout(" inode %p now !flushing\n", inode);
2669
2670		if (ci->i_dirty_caps == 0) {
2671			dout(" inode %p now clean\n", inode);
2672			BUG_ON(!list_empty(&ci->i_dirty_item));
2673			drop = 1;
2674			if (ci->i_wrbuffer_ref_head == 0) {
2675				BUG_ON(!ci->i_head_snapc);
2676				ceph_put_snap_context(ci->i_head_snapc);
2677				ci->i_head_snapc = NULL;
2678			}
2679		} else {
2680			BUG_ON(list_empty(&ci->i_dirty_item));
2681		}
2682	}
2683	spin_unlock(&mdsc->cap_dirty_lock);
2684	wake_up_all(&ci->i_cap_wq);
2685
2686out:
2687	spin_unlock(&ci->i_ceph_lock);
2688	if (drop)
2689		iput(inode);
2690}
2691
2692/*
2693 * Handle FLUSHSNAP_ACK.  MDS has flushed snap data to disk and we can
2694 * throw away our cap_snap.
2695 *
2696 * Caller hold s_mutex.
2697 */
2698static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
2699				     struct ceph_mds_caps *m,
2700				     struct ceph_mds_session *session)
2701{
2702	struct ceph_inode_info *ci = ceph_inode(inode);
2703	u64 follows = le64_to_cpu(m->snap_follows);
2704	struct ceph_cap_snap *capsnap;
2705	int drop = 0;
2706
2707	dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n",
2708	     inode, ci, session->s_mds, follows);
2709
2710	spin_lock(&ci->i_ceph_lock);
2711	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2712		if (capsnap->follows == follows) {
2713			if (capsnap->flush_tid != flush_tid) {
2714				dout(" cap_snap %p follows %lld tid %lld !="
2715				     " %lld\n", capsnap, follows,
2716				     flush_tid, capsnap->flush_tid);
2717				break;
2718			}
2719			WARN_ON(capsnap->dirty_pages || capsnap->writing);
2720			dout(" removing %p cap_snap %p follows %lld\n",
2721			     inode, capsnap, follows);
2722			ceph_put_snap_context(capsnap->context);
2723			list_del(&capsnap->ci_item);
2724			list_del(&capsnap->flushing_item);
2725			ceph_put_cap_snap(capsnap);
2726			drop = 1;
2727			break;
2728		} else {
2729			dout(" skipping cap_snap %p follows %lld\n",
2730			     capsnap, capsnap->follows);
2731		}
2732	}
2733	spin_unlock(&ci->i_ceph_lock);
2734	if (drop)
2735		iput(inode);
2736}
2737
2738/*
2739 * Handle TRUNC from MDS, indicating file truncation.
2740 *
2741 * caller hold s_mutex.
2742 */
2743static void handle_cap_trunc(struct inode *inode,
2744			     struct ceph_mds_caps *trunc,
2745			     struct ceph_mds_session *session)
2746	__releases(ci->i_ceph_lock)
2747{
2748	struct ceph_inode_info *ci = ceph_inode(inode);
2749	int mds = session->s_mds;
2750	int seq = le32_to_cpu(trunc->seq);
2751	u32 truncate_seq = le32_to_cpu(trunc->truncate_seq);
2752	u64 truncate_size = le64_to_cpu(trunc->truncate_size);
2753	u64 size = le64_to_cpu(trunc->size);
2754	int implemented = 0;
2755	int dirty = __ceph_caps_dirty(ci);
2756	int issued = __ceph_caps_issued(ceph_inode(inode), &implemented);
2757	int queue_trunc = 0;
2758
2759	issued |= implemented | dirty;
2760
2761	dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n",
2762	     inode, mds, seq, truncate_size, truncate_seq);
2763	queue_trunc = ceph_fill_file_size(inode, issued,
2764					  truncate_seq, truncate_size, size);
2765	spin_unlock(&ci->i_ceph_lock);
2766
2767	if (queue_trunc) {
2768		ceph_queue_vmtruncate(inode);
2769		ceph_fscache_invalidate(inode);
2770	}
2771}
2772
2773/*
2774 * Handle EXPORT from MDS.  Cap is being migrated _from_ this mds to a
2775 * different one.  If we are the most recent migration we've seen (as
2776 * indicated by mseq), make note of the migrating cap bits for the
2777 * duration (until we see the corresponding IMPORT).
2778 *
2779 * caller holds s_mutex
2780 */
2781static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
2782			      struct ceph_mds_cap_peer *ph,
2783			      struct ceph_mds_session *session)
2784{
2785	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
2786	struct ceph_mds_session *tsession = NULL;
2787	struct ceph_cap *cap, *tcap;
2788	struct ceph_inode_info *ci = ceph_inode(inode);
2789	u64 t_cap_id;
2790	unsigned mseq = le32_to_cpu(ex->migrate_seq);
2791	unsigned t_seq, t_mseq;
2792	int target, issued;
2793	int mds = session->s_mds;
 
 
 
 
2794
2795	if (ph) {
2796		t_cap_id = le64_to_cpu(ph->cap_id);
2797		t_seq = le32_to_cpu(ph->seq);
2798		t_mseq = le32_to_cpu(ph->mseq);
2799		target = le32_to_cpu(ph->mds);
2800	} else {
2801		t_cap_id = t_seq = t_mseq = 0;
2802		target = -1;
2803	}
2804
2805	dout("handle_cap_export inode %p ci %p mds%d mseq %d target %d\n",
2806	     inode, ci, mds, mseq, target);
2807retry:
2808	spin_lock(&ci->i_ceph_lock);
2809	cap = __get_cap_for_mds(ci, mds);
2810	if (!cap)
2811		goto out_unlock;
2812
2813	if (target < 0) {
2814		__ceph_remove_cap(cap, false);
2815		goto out_unlock;
2816	}
2817
2818	/*
2819	 * now we know we haven't received the cap import message yet
2820	 * because the exported cap still exist.
2821	 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2822
2823	issued = cap->issued;
2824	WARN_ON(issued != cap->implemented);
 
 
 
2825
2826	tcap = __get_cap_for_mds(ci, target);
2827	if (tcap) {
2828		/* already have caps from the target */
2829		if (tcap->cap_id != t_cap_id ||
2830		    ceph_seq_cmp(tcap->seq, t_seq) < 0) {
2831			dout(" updating import cap %p mds%d\n", tcap, target);
2832			tcap->cap_id = t_cap_id;
2833			tcap->seq = t_seq - 1;
2834			tcap->issue_seq = t_seq - 1;
2835			tcap->mseq = t_mseq;
2836			tcap->issued |= issued;
2837			tcap->implemented |= issued;
2838			if (cap == ci->i_auth_cap)
2839				ci->i_auth_cap = tcap;
2840			if (ci->i_flushing_caps && ci->i_auth_cap == tcap) {
2841				spin_lock(&mdsc->cap_dirty_lock);
2842				list_move_tail(&ci->i_flushing_item,
2843					       &tcap->session->s_cap_flushing);
2844				spin_unlock(&mdsc->cap_dirty_lock);
2845			}
 
2846		}
2847		__ceph_remove_cap(cap, false);
2848		goto out_unlock;
2849	}
2850
2851	if (tsession) {
2852		int flag = (cap == ci->i_auth_cap) ? CEPH_CAP_FLAG_AUTH : 0;
2853		spin_unlock(&ci->i_ceph_lock);
2854		/* add placeholder for the export tagert */
2855		ceph_add_cap(inode, tsession, t_cap_id, -1, issued, 0,
2856			     t_seq - 1, t_mseq, (u64)-1, flag, NULL);
2857		goto retry;
2858	}
 
2859
2860	spin_unlock(&ci->i_ceph_lock);
2861	mutex_unlock(&session->s_mutex);
2862
2863	/* open target session */
2864	tsession = ceph_mdsc_open_export_target_session(mdsc, target);
2865	if (!IS_ERR(tsession)) {
2866		if (mds > target) {
2867			mutex_lock(&session->s_mutex);
2868			mutex_lock_nested(&tsession->s_mutex,
2869					  SINGLE_DEPTH_NESTING);
2870		} else {
2871			mutex_lock(&tsession->s_mutex);
2872			mutex_lock_nested(&session->s_mutex,
2873					  SINGLE_DEPTH_NESTING);
2874		}
2875		ceph_add_cap_releases(mdsc, tsession);
2876	} else {
2877		WARN_ON(1);
2878		tsession = NULL;
2879		target = -1;
2880	}
2881	goto retry;
2882
2883out_unlock:
2884	spin_unlock(&ci->i_ceph_lock);
2885	mutex_unlock(&session->s_mutex);
2886	if (tsession) {
2887		mutex_unlock(&tsession->s_mutex);
2888		ceph_put_mds_session(tsession);
2889	}
2890}
2891
2892/*
2893 * Handle cap IMPORT.  If there are temp bits from an older EXPORT,
2894 * clean them up.
2895 *
2896 * caller holds s_mutex.
2897 */
2898static void handle_cap_import(struct ceph_mds_client *mdsc,
2899			      struct inode *inode, struct ceph_mds_caps *im,
2900			      struct ceph_mds_cap_peer *ph,
2901			      struct ceph_mds_session *session,
2902			      void *snaptrace, int snaptrace_len)
2903{
2904	struct ceph_inode_info *ci = ceph_inode(inode);
2905	struct ceph_cap *cap;
2906	int mds = session->s_mds;
2907	unsigned issued = le32_to_cpu(im->caps);
2908	unsigned wanted = le32_to_cpu(im->wanted);
2909	unsigned seq = le32_to_cpu(im->seq);
2910	unsigned mseq = le32_to_cpu(im->migrate_seq);
2911	u64 realmino = le64_to_cpu(im->realm);
2912	u64 cap_id = le64_to_cpu(im->cap_id);
2913	u64 p_cap_id;
2914	int peer;
2915
2916	if (ph) {
2917		p_cap_id = le64_to_cpu(ph->cap_id);
2918		peer = le32_to_cpu(ph->mds);
2919	} else {
2920		p_cap_id = 0;
2921		peer = -1;
2922	}
2923
2924	dout("handle_cap_import inode %p ci %p mds%d mseq %d peer %d\n",
2925	     inode, ci, mds, mseq, peer);
2926
2927	spin_lock(&ci->i_ceph_lock);
2928	cap = peer >= 0 ? __get_cap_for_mds(ci, peer) : NULL;
2929	if (cap && cap->cap_id == p_cap_id) {
2930		dout(" remove export cap %p mds%d flags %d\n",
2931		     cap, peer, ph->flags);
2932		if ((ph->flags & CEPH_CAP_FLAG_AUTH) &&
2933		    (cap->seq != le32_to_cpu(ph->seq) ||
2934		     cap->mseq != le32_to_cpu(ph->mseq))) {
2935			pr_err("handle_cap_import: mismatched seq/mseq: "
2936			       "ino (%llx.%llx) mds%d seq %d mseq %d "
2937			       "importer mds%d has peer seq %d mseq %d\n",
2938			       ceph_vinop(inode), peer, cap->seq,
2939			       cap->mseq, mds, le32_to_cpu(ph->seq),
2940			       le32_to_cpu(ph->mseq));
2941		}
2942		ci->i_cap_exporting_issued = cap->issued;
2943		__ceph_remove_cap(cap, (ph->flags & CEPH_CAP_FLAG_RELEASE));
 
 
2944	}
2945
2946	/* make sure we re-request max_size, if necessary */
2947	ci->i_wanted_max_size = 0;
2948	ci->i_requested_max_size = 0;
2949	spin_unlock(&ci->i_ceph_lock);
2950
2951	down_write(&mdsc->snap_rwsem);
2952	ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len,
2953			       false);
2954	downgrade_write(&mdsc->snap_rwsem);
2955	ceph_add_cap(inode, session, cap_id, -1,
2956		     issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH,
2957		     NULL /* no caps context */);
2958	kick_flushing_inode_caps(mdsc, session, inode);
2959	up_read(&mdsc->snap_rwsem);
2960
 
 
 
 
2961}
2962
2963/*
2964 * Handle a caps message from the MDS.
2965 *
2966 * Identify the appropriate session, inode, and call the right handler
2967 * based on the cap op.
2968 */
2969void ceph_handle_caps(struct ceph_mds_session *session,
2970		      struct ceph_msg *msg)
2971{
2972	struct ceph_mds_client *mdsc = session->s_mdsc;
2973	struct super_block *sb = mdsc->fsc->sb;
2974	struct inode *inode;
2975	struct ceph_inode_info *ci;
2976	struct ceph_cap *cap;
2977	struct ceph_mds_caps *h;
2978	struct ceph_mds_cap_peer *peer = NULL;
2979	int mds = session->s_mds;
2980	int op;
2981	u32 seq, mseq;
2982	struct ceph_vino vino;
2983	u64 cap_id;
2984	u64 size, max_size;
2985	u64 tid;
2986	void *snaptrace;
2987	size_t snaptrace_len;
2988	void *flock;
2989	void *end;
2990	u32 flock_len;
 
2991
2992	dout("handle_caps from mds%d\n", mds);
2993
2994	/* decode */
2995	end = msg->front.iov_base + msg->front.iov_len;
2996	tid = le64_to_cpu(msg->hdr.tid);
2997	if (msg->front.iov_len < sizeof(*h))
2998		goto bad;
2999	h = msg->front.iov_base;
3000	op = le32_to_cpu(h->op);
3001	vino.ino = le64_to_cpu(h->ino);
3002	vino.snap = CEPH_NOSNAP;
3003	cap_id = le64_to_cpu(h->cap_id);
3004	seq = le32_to_cpu(h->seq);
3005	mseq = le32_to_cpu(h->migrate_seq);
3006	size = le64_to_cpu(h->size);
3007	max_size = le64_to_cpu(h->max_size);
3008
3009	snaptrace = h + 1;
3010	snaptrace_len = le32_to_cpu(h->snap_trace_len);
3011
3012	if (le16_to_cpu(msg->hdr.version) >= 2) {
3013		void *p = snaptrace + snaptrace_len;
 
 
 
3014		ceph_decode_32_safe(&p, end, flock_len, bad);
3015		if (p + flock_len > end)
3016			goto bad;
3017		flock = p;
3018	} else {
3019		flock = NULL;
3020		flock_len = 0;
3021	}
3022
3023	if (le16_to_cpu(msg->hdr.version) >= 3) {
3024		if (op == CEPH_CAP_OP_IMPORT) {
3025			void *p = flock + flock_len;
3026			if (p + sizeof(*peer) > end)
3027				goto bad;
3028			peer = p;
3029		} else if (op == CEPH_CAP_OP_EXPORT) {
3030			/* recorded in unused fields */
3031			peer = (void *)&h->size;
3032		}
3033	}
3034
3035	mutex_lock(&session->s_mutex);
3036	session->s_seq++;
3037	dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
3038	     (unsigned)seq);
3039
3040	if (op == CEPH_CAP_OP_IMPORT)
3041		ceph_add_cap_releases(mdsc, session);
3042
3043	/* lookup ino */
3044	inode = ceph_find_inode(sb, vino);
3045	ci = ceph_inode(inode);
3046	dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
3047	     vino.snap, inode);
3048	if (!inode) {
3049		dout(" i don't have ino %llx\n", vino.ino);
3050
3051		if (op == CEPH_CAP_OP_IMPORT) {
3052			spin_lock(&session->s_cap_lock);
3053			__queue_cap_release(session, vino.ino, cap_id,
3054					    mseq, seq);
3055			spin_unlock(&session->s_cap_lock);
3056		}
3057		goto flush_cap_releases;
3058	}
3059
3060	/* these will work even if we don't have a cap yet */
3061	switch (op) {
3062	case CEPH_CAP_OP_FLUSHSNAP_ACK:
3063		handle_cap_flushsnap_ack(inode, tid, h, session);
3064		goto done;
3065
3066	case CEPH_CAP_OP_EXPORT:
3067		handle_cap_export(inode, h, peer, session);
3068		goto done_unlocked;
3069
3070	case CEPH_CAP_OP_IMPORT:
3071		handle_cap_import(mdsc, inode, h, peer, session,
3072				  snaptrace, snaptrace_len);
 
 
3073	}
3074
3075	/* the rest require a cap */
3076	spin_lock(&ci->i_ceph_lock);
3077	cap = __get_cap_for_mds(ceph_inode(inode), mds);
3078	if (!cap) {
3079		dout(" no cap on %p ino %llx.%llx from mds%d\n",
3080		     inode, ceph_ino(inode), ceph_snap(inode), mds);
3081		spin_unlock(&ci->i_ceph_lock);
3082		goto flush_cap_releases;
3083	}
3084
3085	/* note that each of these drops i_ceph_lock for us */
3086	switch (op) {
3087	case CEPH_CAP_OP_REVOKE:
3088	case CEPH_CAP_OP_GRANT:
3089	case CEPH_CAP_OP_IMPORT:
3090		handle_cap_grant(inode, h, session, cap, msg->middle);
3091		goto done_unlocked;
3092
3093	case CEPH_CAP_OP_FLUSH_ACK:
3094		handle_cap_flush_ack(inode, tid, h, session, cap);
3095		break;
3096
3097	case CEPH_CAP_OP_TRUNC:
3098		handle_cap_trunc(inode, h, session);
3099		break;
3100
3101	default:
3102		spin_unlock(&ci->i_ceph_lock);
3103		pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
3104		       ceph_cap_op_name(op));
3105	}
3106
3107	goto done;
3108
3109flush_cap_releases:
3110	/*
3111	 * send any full release message to try to move things
3112	 * along for the mds (who clearly thinks we still have this
3113	 * cap).
3114	 */
3115	ceph_add_cap_releases(mdsc, session);
3116	ceph_send_cap_releases(mdsc, session);
3117
3118done:
3119	mutex_unlock(&session->s_mutex);
3120done_unlocked:
3121	if (inode)
3122		iput(inode);
 
 
3123	return;
3124
3125bad:
3126	pr_err("ceph_handle_caps: corrupt message\n");
3127	ceph_msg_dump(msg);
3128	return;
3129}
3130
3131/*
3132 * Delayed work handler to process end of delayed cap release LRU list.
3133 */
3134void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
3135{
3136	struct ceph_inode_info *ci;
3137	int flags = CHECK_CAPS_NODELAY;
3138
3139	dout("check_delayed_caps\n");
3140	while (1) {
3141		spin_lock(&mdsc->cap_delay_lock);
3142		if (list_empty(&mdsc->cap_delay_list))
3143			break;
3144		ci = list_first_entry(&mdsc->cap_delay_list,
3145				      struct ceph_inode_info,
3146				      i_cap_delay_list);
3147		if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 &&
3148		    time_before(jiffies, ci->i_hold_caps_max))
3149			break;
3150		list_del_init(&ci->i_cap_delay_list);
3151		spin_unlock(&mdsc->cap_delay_lock);
3152		dout("check_delayed_caps on %p\n", &ci->vfs_inode);
3153		ceph_check_caps(ci, flags, NULL);
3154	}
3155	spin_unlock(&mdsc->cap_delay_lock);
3156}
3157
3158/*
3159 * Flush all dirty caps to the mds
3160 */
3161void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
3162{
3163	struct ceph_inode_info *ci;
3164	struct inode *inode;
3165
3166	dout("flush_dirty_caps\n");
3167	spin_lock(&mdsc->cap_dirty_lock);
3168	while (!list_empty(&mdsc->cap_dirty)) {
3169		ci = list_first_entry(&mdsc->cap_dirty, struct ceph_inode_info,
3170				      i_dirty_item);
3171		inode = &ci->vfs_inode;
3172		ihold(inode);
3173		dout("flush_dirty_caps %p\n", inode);
3174		spin_unlock(&mdsc->cap_dirty_lock);
3175		ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH, NULL);
3176		iput(inode);
3177		spin_lock(&mdsc->cap_dirty_lock);
3178	}
3179	spin_unlock(&mdsc->cap_dirty_lock);
3180	dout("flush_dirty_caps done\n");
3181}
3182
3183/*
3184 * Drop open file reference.  If we were the last open file,
3185 * we may need to release capabilities to the MDS (or schedule
3186 * their delayed release).
3187 */
3188void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
3189{
3190	struct inode *inode = &ci->vfs_inode;
3191	int last = 0;
3192
3193	spin_lock(&ci->i_ceph_lock);
3194	dout("put_fmode %p fmode %d %d -> %d\n", inode, fmode,
3195	     ci->i_nr_by_mode[fmode], ci->i_nr_by_mode[fmode]-1);
3196	BUG_ON(ci->i_nr_by_mode[fmode] == 0);
3197	if (--ci->i_nr_by_mode[fmode] == 0)
3198		last++;
3199	spin_unlock(&ci->i_ceph_lock);
3200
3201	if (last && ci->i_vino.snap == CEPH_NOSNAP)
3202		ceph_check_caps(ci, 0, NULL);
3203}
3204
3205/*
3206 * Helpers for embedding cap and dentry lease releases into mds
3207 * requests.
3208 *
3209 * @force is used by dentry_release (below) to force inclusion of a
3210 * record for the directory inode, even when there aren't any caps to
3211 * drop.
3212 */
3213int ceph_encode_inode_release(void **p, struct inode *inode,
3214			      int mds, int drop, int unless, int force)
3215{
3216	struct ceph_inode_info *ci = ceph_inode(inode);
3217	struct ceph_cap *cap;
3218	struct ceph_mds_request_release *rel = *p;
3219	int used, dirty;
3220	int ret = 0;
3221
3222	spin_lock(&ci->i_ceph_lock);
3223	used = __ceph_caps_used(ci);
3224	dirty = __ceph_caps_dirty(ci);
3225
3226	dout("encode_inode_release %p mds%d used|dirty %s drop %s unless %s\n",
3227	     inode, mds, ceph_cap_string(used|dirty), ceph_cap_string(drop),
3228	     ceph_cap_string(unless));
3229
3230	/* only drop unused, clean caps */
3231	drop &= ~(used | dirty);
3232
3233	cap = __get_cap_for_mds(ci, mds);
3234	if (cap && __cap_is_valid(cap)) {
3235		if (force ||
3236		    ((cap->issued & drop) &&
3237		     (cap->issued & unless) == 0)) {
3238			if ((cap->issued & drop) &&
3239			    (cap->issued & unless) == 0) {
3240				int wanted = __ceph_caps_wanted(ci);
3241				if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0)
3242					wanted |= cap->mds_wanted;
3243				dout("encode_inode_release %p cap %p "
3244				     "%s -> %s, wanted %s -> %s\n", inode, cap,
3245				     ceph_cap_string(cap->issued),
3246				     ceph_cap_string(cap->issued & ~drop),
3247				     ceph_cap_string(cap->mds_wanted),
3248				     ceph_cap_string(wanted));
3249
3250				cap->issued &= ~drop;
3251				cap->implemented &= ~drop;
3252				cap->mds_wanted = wanted;
 
 
 
 
 
 
 
 
3253			} else {
3254				dout("encode_inode_release %p cap %p %s"
3255				     " (force)\n", inode, cap,
3256				     ceph_cap_string(cap->issued));
3257			}
3258
3259			rel->ino = cpu_to_le64(ceph_ino(inode));
3260			rel->cap_id = cpu_to_le64(cap->cap_id);
3261			rel->seq = cpu_to_le32(cap->seq);
3262			rel->issue_seq = cpu_to_le32(cap->issue_seq),
3263			rel->mseq = cpu_to_le32(cap->mseq);
3264			rel->caps = cpu_to_le32(cap->implemented);
3265			rel->wanted = cpu_to_le32(cap->mds_wanted);
3266			rel->dname_len = 0;
3267			rel->dname_seq = 0;
3268			*p += sizeof(*rel);
3269			ret = 1;
3270		} else {
3271			dout("encode_inode_release %p cap %p %s\n",
3272			     inode, cap, ceph_cap_string(cap->issued));
3273		}
3274	}
3275	spin_unlock(&ci->i_ceph_lock);
3276	return ret;
3277}
3278
3279int ceph_encode_dentry_release(void **p, struct dentry *dentry,
3280			       int mds, int drop, int unless)
3281{
3282	struct inode *dir = dentry->d_parent->d_inode;
3283	struct ceph_mds_request_release *rel = *p;
3284	struct ceph_dentry_info *di = ceph_dentry(dentry);
3285	int force = 0;
3286	int ret;
3287
3288	/*
3289	 * force an record for the directory caps if we have a dentry lease.
3290	 * this is racy (can't take i_ceph_lock and d_lock together), but it
3291	 * doesn't have to be perfect; the mds will revoke anything we don't
3292	 * release.
3293	 */
3294	spin_lock(&dentry->d_lock);
3295	if (di->lease_session && di->lease_session->s_mds == mds)
3296		force = 1;
3297	spin_unlock(&dentry->d_lock);
3298
3299	ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force);
3300
3301	spin_lock(&dentry->d_lock);
3302	if (ret && di->lease_session && di->lease_session->s_mds == mds) {
3303		dout("encode_dentry_release %p mds%d seq %d\n",
3304		     dentry, mds, (int)di->lease_seq);
3305		rel->dname_len = cpu_to_le32(dentry->d_name.len);
3306		memcpy(*p, dentry->d_name.name, dentry->d_name.len);
3307		*p += dentry->d_name.len;
3308		rel->dname_seq = cpu_to_le32(di->lease_seq);
3309		__ceph_mdsc_drop_dentry_lease(dentry);
3310	}
3311	spin_unlock(&dentry->d_lock);
3312	return ret;
3313}
v3.5.6
   1#include <linux/ceph/ceph_debug.h>
   2
   3#include <linux/fs.h>
   4#include <linux/kernel.h>
   5#include <linux/sched.h>
   6#include <linux/slab.h>
   7#include <linux/vmalloc.h>
   8#include <linux/wait.h>
   9#include <linux/writeback.h>
  10
  11#include "super.h"
  12#include "mds_client.h"
 
  13#include <linux/ceph/decode.h>
  14#include <linux/ceph/messenger.h>
  15
  16/*
  17 * Capability management
  18 *
  19 * The Ceph metadata servers control client access to inode metadata
  20 * and file data by issuing capabilities, granting clients permission
  21 * to read and/or write both inode field and file data to OSDs
  22 * (storage nodes).  Each capability consists of a set of bits
  23 * indicating which operations are allowed.
  24 *
  25 * If the client holds a *_SHARED cap, the client has a coherent value
  26 * that can be safely read from the cached inode.
  27 *
  28 * In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the
  29 * client is allowed to change inode attributes (e.g., file size,
  30 * mtime), note its dirty state in the ceph_cap, and asynchronously
  31 * flush that metadata change to the MDS.
  32 *
  33 * In the event of a conflicting operation (perhaps by another
  34 * client), the MDS will revoke the conflicting client capabilities.
  35 *
  36 * In order for a client to cache an inode, it must hold a capability
  37 * with at least one MDS server.  When inodes are released, release
  38 * notifications are batched and periodically sent en masse to the MDS
  39 * cluster to release server state.
  40 */
  41
  42
  43/*
  44 * Generate readable cap strings for debugging output.
  45 */
  46#define MAX_CAP_STR 20
  47static char cap_str[MAX_CAP_STR][40];
  48static DEFINE_SPINLOCK(cap_str_lock);
  49static int last_cap_str;
  50
  51static char *gcap_string(char *s, int c)
  52{
  53	if (c & CEPH_CAP_GSHARED)
  54		*s++ = 's';
  55	if (c & CEPH_CAP_GEXCL)
  56		*s++ = 'x';
  57	if (c & CEPH_CAP_GCACHE)
  58		*s++ = 'c';
  59	if (c & CEPH_CAP_GRD)
  60		*s++ = 'r';
  61	if (c & CEPH_CAP_GWR)
  62		*s++ = 'w';
  63	if (c & CEPH_CAP_GBUFFER)
  64		*s++ = 'b';
  65	if (c & CEPH_CAP_GLAZYIO)
  66		*s++ = 'l';
  67	return s;
  68}
  69
  70const char *ceph_cap_string(int caps)
  71{
  72	int i;
  73	char *s;
  74	int c;
  75
  76	spin_lock(&cap_str_lock);
  77	i = last_cap_str++;
  78	if (last_cap_str == MAX_CAP_STR)
  79		last_cap_str = 0;
  80	spin_unlock(&cap_str_lock);
  81
  82	s = cap_str[i];
  83
  84	if (caps & CEPH_CAP_PIN)
  85		*s++ = 'p';
  86
  87	c = (caps >> CEPH_CAP_SAUTH) & 3;
  88	if (c) {
  89		*s++ = 'A';
  90		s = gcap_string(s, c);
  91	}
  92
  93	c = (caps >> CEPH_CAP_SLINK) & 3;
  94	if (c) {
  95		*s++ = 'L';
  96		s = gcap_string(s, c);
  97	}
  98
  99	c = (caps >> CEPH_CAP_SXATTR) & 3;
 100	if (c) {
 101		*s++ = 'X';
 102		s = gcap_string(s, c);
 103	}
 104
 105	c = caps >> CEPH_CAP_SFILE;
 106	if (c) {
 107		*s++ = 'F';
 108		s = gcap_string(s, c);
 109	}
 110
 111	if (s == cap_str[i])
 112		*s++ = '-';
 113	*s = 0;
 114	return cap_str[i];
 115}
 116
 117void ceph_caps_init(struct ceph_mds_client *mdsc)
 118{
 119	INIT_LIST_HEAD(&mdsc->caps_list);
 120	spin_lock_init(&mdsc->caps_list_lock);
 121}
 122
 123void ceph_caps_finalize(struct ceph_mds_client *mdsc)
 124{
 125	struct ceph_cap *cap;
 126
 127	spin_lock(&mdsc->caps_list_lock);
 128	while (!list_empty(&mdsc->caps_list)) {
 129		cap = list_first_entry(&mdsc->caps_list,
 130				       struct ceph_cap, caps_item);
 131		list_del(&cap->caps_item);
 132		kmem_cache_free(ceph_cap_cachep, cap);
 133	}
 134	mdsc->caps_total_count = 0;
 135	mdsc->caps_avail_count = 0;
 136	mdsc->caps_use_count = 0;
 137	mdsc->caps_reserve_count = 0;
 138	mdsc->caps_min_count = 0;
 139	spin_unlock(&mdsc->caps_list_lock);
 140}
 141
 142void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
 143{
 144	spin_lock(&mdsc->caps_list_lock);
 145	mdsc->caps_min_count += delta;
 146	BUG_ON(mdsc->caps_min_count < 0);
 147	spin_unlock(&mdsc->caps_list_lock);
 148}
 149
 150int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 151		      struct ceph_cap_reservation *ctx, int need)
 152{
 153	int i;
 154	struct ceph_cap *cap;
 155	int have;
 156	int alloc = 0;
 157	LIST_HEAD(newcaps);
 158	int ret = 0;
 159
 160	dout("reserve caps ctx=%p need=%d\n", ctx, need);
 161
 162	/* first reserve any caps that are already allocated */
 163	spin_lock(&mdsc->caps_list_lock);
 164	if (mdsc->caps_avail_count >= need)
 165		have = need;
 166	else
 167		have = mdsc->caps_avail_count;
 168	mdsc->caps_avail_count -= have;
 169	mdsc->caps_reserve_count += have;
 170	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 171					 mdsc->caps_reserve_count +
 172					 mdsc->caps_avail_count);
 173	spin_unlock(&mdsc->caps_list_lock);
 174
 175	for (i = have; i < need; i++) {
 176		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 177		if (!cap) {
 178			ret = -ENOMEM;
 179			goto out_alloc_count;
 180		}
 181		list_add(&cap->caps_item, &newcaps);
 182		alloc++;
 183	}
 184	BUG_ON(have + alloc != need);
 
 
 
 185
 186	spin_lock(&mdsc->caps_list_lock);
 187	mdsc->caps_total_count += alloc;
 188	mdsc->caps_reserve_count += alloc;
 189	list_splice(&newcaps, &mdsc->caps_list);
 190
 191	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 192					 mdsc->caps_reserve_count +
 193					 mdsc->caps_avail_count);
 194	spin_unlock(&mdsc->caps_list_lock);
 195
 196	ctx->count = need;
 197	dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
 198	     ctx, mdsc->caps_total_count, mdsc->caps_use_count,
 199	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 200	return 0;
 201
 202out_alloc_count:
 203	/* we didn't manage to reserve as much as we needed */
 204	pr_warning("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
 205		   ctx, need, have);
 206	return ret;
 207}
 208
 209int ceph_unreserve_caps(struct ceph_mds_client *mdsc,
 210			struct ceph_cap_reservation *ctx)
 211{
 212	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
 213	if (ctx->count) {
 214		spin_lock(&mdsc->caps_list_lock);
 215		BUG_ON(mdsc->caps_reserve_count < ctx->count);
 216		mdsc->caps_reserve_count -= ctx->count;
 217		mdsc->caps_avail_count += ctx->count;
 218		ctx->count = 0;
 219		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
 220		     mdsc->caps_total_count, mdsc->caps_use_count,
 221		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 222		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 223						 mdsc->caps_reserve_count +
 224						 mdsc->caps_avail_count);
 225		spin_unlock(&mdsc->caps_list_lock);
 226	}
 227	return 0;
 228}
 229
 230static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
 231				struct ceph_cap_reservation *ctx)
 232{
 233	struct ceph_cap *cap = NULL;
 234
 235	/* temporary, until we do something about cap import/export */
 236	if (!ctx) {
 237		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 238		if (cap) {
 
 239			mdsc->caps_use_count++;
 240			mdsc->caps_total_count++;
 
 241		}
 242		return cap;
 243	}
 244
 245	spin_lock(&mdsc->caps_list_lock);
 246	dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
 247	     ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
 248	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 249	BUG_ON(!ctx->count);
 250	BUG_ON(ctx->count > mdsc->caps_reserve_count);
 251	BUG_ON(list_empty(&mdsc->caps_list));
 252
 253	ctx->count--;
 254	mdsc->caps_reserve_count--;
 255	mdsc->caps_use_count++;
 256
 257	cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
 258	list_del(&cap->caps_item);
 259
 260	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 261	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
 262	spin_unlock(&mdsc->caps_list_lock);
 263	return cap;
 264}
 265
 266void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
 267{
 268	spin_lock(&mdsc->caps_list_lock);
 269	dout("put_cap %p %d = %d used + %d resv + %d avail\n",
 270	     cap, mdsc->caps_total_count, mdsc->caps_use_count,
 271	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
 272	mdsc->caps_use_count--;
 273	/*
 274	 * Keep some preallocated caps around (ceph_min_count), to
 275	 * avoid lots of free/alloc churn.
 276	 */
 277	if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
 278				      mdsc->caps_min_count) {
 279		mdsc->caps_total_count--;
 280		kmem_cache_free(ceph_cap_cachep, cap);
 281	} else {
 282		mdsc->caps_avail_count++;
 283		list_add(&cap->caps_item, &mdsc->caps_list);
 284	}
 285
 286	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
 287	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
 288	spin_unlock(&mdsc->caps_list_lock);
 289}
 290
 291void ceph_reservation_status(struct ceph_fs_client *fsc,
 292			     int *total, int *avail, int *used, int *reserved,
 293			     int *min)
 294{
 295	struct ceph_mds_client *mdsc = fsc->mdsc;
 296
 297	if (total)
 298		*total = mdsc->caps_total_count;
 299	if (avail)
 300		*avail = mdsc->caps_avail_count;
 301	if (used)
 302		*used = mdsc->caps_use_count;
 303	if (reserved)
 304		*reserved = mdsc->caps_reserve_count;
 305	if (min)
 306		*min = mdsc->caps_min_count;
 307}
 308
 309/*
 310 * Find ceph_cap for given mds, if any.
 311 *
 312 * Called with i_ceph_lock held.
 313 */
 314static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 315{
 316	struct ceph_cap *cap;
 317	struct rb_node *n = ci->i_caps.rb_node;
 318
 319	while (n) {
 320		cap = rb_entry(n, struct ceph_cap, ci_node);
 321		if (mds < cap->mds)
 322			n = n->rb_left;
 323		else if (mds > cap->mds)
 324			n = n->rb_right;
 325		else
 326			return cap;
 327	}
 328	return NULL;
 329}
 330
 331struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci, int mds)
 332{
 333	struct ceph_cap *cap;
 334
 335	spin_lock(&ci->i_ceph_lock);
 336	cap = __get_cap_for_mds(ci, mds);
 337	spin_unlock(&ci->i_ceph_lock);
 338	return cap;
 339}
 340
 341/*
 342 * Return id of any MDS with a cap, preferably FILE_WR|BUFFER|EXCL, else -1.
 343 */
 344static int __ceph_get_cap_mds(struct ceph_inode_info *ci)
 345{
 346	struct ceph_cap *cap;
 347	int mds = -1;
 348	struct rb_node *p;
 349
 350	/* prefer mds with WR|BUFFER|EXCL caps */
 351	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 352		cap = rb_entry(p, struct ceph_cap, ci_node);
 353		mds = cap->mds;
 354		if (cap->issued & (CEPH_CAP_FILE_WR |
 355				   CEPH_CAP_FILE_BUFFER |
 356				   CEPH_CAP_FILE_EXCL))
 357			break;
 358	}
 359	return mds;
 360}
 361
 362int ceph_get_cap_mds(struct inode *inode)
 363{
 364	struct ceph_inode_info *ci = ceph_inode(inode);
 365	int mds;
 366	spin_lock(&ci->i_ceph_lock);
 367	mds = __ceph_get_cap_mds(ceph_inode(inode));
 368	spin_unlock(&ci->i_ceph_lock);
 369	return mds;
 370}
 371
 372/*
 373 * Called under i_ceph_lock.
 374 */
 375static void __insert_cap_node(struct ceph_inode_info *ci,
 376			      struct ceph_cap *new)
 377{
 378	struct rb_node **p = &ci->i_caps.rb_node;
 379	struct rb_node *parent = NULL;
 380	struct ceph_cap *cap = NULL;
 381
 382	while (*p) {
 383		parent = *p;
 384		cap = rb_entry(parent, struct ceph_cap, ci_node);
 385		if (new->mds < cap->mds)
 386			p = &(*p)->rb_left;
 387		else if (new->mds > cap->mds)
 388			p = &(*p)->rb_right;
 389		else
 390			BUG();
 391	}
 392
 393	rb_link_node(&new->ci_node, parent, p);
 394	rb_insert_color(&new->ci_node, &ci->i_caps);
 395}
 396
 397/*
 398 * (re)set cap hold timeouts, which control the delayed release
 399 * of unused caps back to the MDS.  Should be called on cap use.
 400 */
 401static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
 402			       struct ceph_inode_info *ci)
 403{
 404	struct ceph_mount_options *ma = mdsc->fsc->mount_options;
 405
 406	ci->i_hold_caps_min = round_jiffies(jiffies +
 407					    ma->caps_wanted_delay_min * HZ);
 408	ci->i_hold_caps_max = round_jiffies(jiffies +
 409					    ma->caps_wanted_delay_max * HZ);
 410	dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
 411	     ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
 412}
 413
 414/*
 415 * (Re)queue cap at the end of the delayed cap release list.
 416 *
 417 * If I_FLUSH is set, leave the inode at the front of the list.
 418 *
 419 * Caller holds i_ceph_lock
 420 *    -> we take mdsc->cap_delay_lock
 421 */
 422static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
 423				struct ceph_inode_info *ci)
 424{
 425	__cap_set_timeouts(mdsc, ci);
 426	dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
 427	     ci->i_ceph_flags, ci->i_hold_caps_max);
 428	if (!mdsc->stopping) {
 429		spin_lock(&mdsc->cap_delay_lock);
 430		if (!list_empty(&ci->i_cap_delay_list)) {
 431			if (ci->i_ceph_flags & CEPH_I_FLUSH)
 432				goto no_change;
 433			list_del_init(&ci->i_cap_delay_list);
 434		}
 435		list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 436no_change:
 437		spin_unlock(&mdsc->cap_delay_lock);
 438	}
 439}
 440
 441/*
 442 * Queue an inode for immediate writeback.  Mark inode with I_FLUSH,
 443 * indicating we should send a cap message to flush dirty metadata
 444 * asap, and move to the front of the delayed cap list.
 445 */
 446static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
 447				      struct ceph_inode_info *ci)
 448{
 449	dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
 450	spin_lock(&mdsc->cap_delay_lock);
 451	ci->i_ceph_flags |= CEPH_I_FLUSH;
 452	if (!list_empty(&ci->i_cap_delay_list))
 453		list_del_init(&ci->i_cap_delay_list);
 454	list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
 455	spin_unlock(&mdsc->cap_delay_lock);
 456}
 457
 458/*
 459 * Cancel delayed work on cap.
 460 *
 461 * Caller must hold i_ceph_lock.
 462 */
 463static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
 464			       struct ceph_inode_info *ci)
 465{
 466	dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
 467	if (list_empty(&ci->i_cap_delay_list))
 468		return;
 469	spin_lock(&mdsc->cap_delay_lock);
 470	list_del_init(&ci->i_cap_delay_list);
 471	spin_unlock(&mdsc->cap_delay_lock);
 472}
 473
 474/*
 475 * Common issue checks for add_cap, handle_cap_grant.
 476 */
 477static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
 478			      unsigned issued)
 479{
 480	unsigned had = __ceph_caps_issued(ci, NULL);
 481
 482	/*
 483	 * Each time we receive FILE_CACHE anew, we increment
 484	 * i_rdcache_gen.
 485	 */
 486	if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
 487	    (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
 488		ci->i_rdcache_gen++;
 
 489
 490	/*
 491	 * if we are newly issued FILE_SHARED, clear D_COMPLETE; we
 492	 * don't know what happened to this directory while we didn't
 493	 * have the cap.
 494	 */
 495	if ((issued & CEPH_CAP_FILE_SHARED) &&
 496	    (had & CEPH_CAP_FILE_SHARED) == 0) {
 497		ci->i_shared_gen++;
 498		if (S_ISDIR(ci->vfs_inode.i_mode))
 499			ceph_dir_clear_complete(&ci->vfs_inode);
 
 
 500	}
 501}
 502
 503/*
 504 * Add a capability under the given MDS session.
 505 *
 506 * Caller should hold session snap_rwsem (read) and s_mutex.
 507 *
 508 * @fmode is the open file mode, if we are opening a file, otherwise
 509 * it is < 0.  (This is so we can atomically add the cap and add an
 510 * open file reference to it.)
 511 */
 512int ceph_add_cap(struct inode *inode,
 513		 struct ceph_mds_session *session, u64 cap_id,
 514		 int fmode, unsigned issued, unsigned wanted,
 515		 unsigned seq, unsigned mseq, u64 realmino, int flags,
 516		 struct ceph_cap_reservation *caps_reservation)
 517{
 518	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 519	struct ceph_inode_info *ci = ceph_inode(inode);
 520	struct ceph_cap *new_cap = NULL;
 521	struct ceph_cap *cap;
 522	int mds = session->s_mds;
 523	int actual_wanted;
 524
 525	dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
 526	     session->s_mds, cap_id, ceph_cap_string(issued), seq);
 527
 528	/*
 529	 * If we are opening the file, include file mode wanted bits
 530	 * in wanted.
 531	 */
 532	if (fmode >= 0)
 533		wanted |= ceph_caps_for_mode(fmode);
 534
 535retry:
 536	spin_lock(&ci->i_ceph_lock);
 537	cap = __get_cap_for_mds(ci, mds);
 538	if (!cap) {
 539		if (new_cap) {
 540			cap = new_cap;
 541			new_cap = NULL;
 542		} else {
 543			spin_unlock(&ci->i_ceph_lock);
 544			new_cap = get_cap(mdsc, caps_reservation);
 545			if (new_cap == NULL)
 546				return -ENOMEM;
 547			goto retry;
 548		}
 549
 550		cap->issued = 0;
 551		cap->implemented = 0;
 552		cap->mds = mds;
 553		cap->mds_wanted = 0;
 
 554
 555		cap->ci = ci;
 556		__insert_cap_node(ci, cap);
 557
 558		/* clear out old exporting info?  (i.e. on cap import) */
 559		if (ci->i_cap_exporting_mds == mds) {
 560			ci->i_cap_exporting_issued = 0;
 561			ci->i_cap_exporting_mseq = 0;
 562			ci->i_cap_exporting_mds = -1;
 563		}
 564
 565		/* add to session cap list */
 566		cap->session = session;
 567		spin_lock(&session->s_cap_lock);
 568		list_add_tail(&cap->session_caps, &session->s_caps);
 569		session->s_nr_caps++;
 570		spin_unlock(&session->s_cap_lock);
 571	} else if (new_cap)
 572		ceph_put_cap(mdsc, new_cap);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 573
 574	if (!ci->i_snap_realm) {
 575		/*
 576		 * add this inode to the appropriate snap realm
 577		 */
 578		struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
 579							       realmino);
 580		if (realm) {
 581			ceph_get_snap_realm(mdsc, realm);
 582			spin_lock(&realm->inodes_with_caps_lock);
 583			ci->i_snap_realm = realm;
 584			list_add(&ci->i_snap_realm_item,
 585				 &realm->inodes_with_caps);
 586			spin_unlock(&realm->inodes_with_caps_lock);
 587		} else {
 588			pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
 589			       realmino);
 590			WARN_ON(!realm);
 591		}
 592	}
 593
 594	__check_cap_issue(ci, cap, issued);
 595
 596	/*
 597	 * If we are issued caps we don't want, or the mds' wanted
 598	 * value appears to be off, queue a check so we'll release
 599	 * later and/or update the mds wanted value.
 600	 */
 601	actual_wanted = __ceph_caps_wanted(ci);
 602	if ((wanted & ~actual_wanted) ||
 603	    (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
 604		dout(" issued %s, mds wanted %s, actual %s, queueing\n",
 605		     ceph_cap_string(issued), ceph_cap_string(wanted),
 606		     ceph_cap_string(actual_wanted));
 607		__cap_delay_requeue(mdsc, ci);
 608	}
 609
 610	if (flags & CEPH_CAP_FLAG_AUTH)
 611		ci->i_auth_cap = cap;
 612	else if (ci->i_auth_cap == cap)
 613		ci->i_auth_cap = NULL;
 
 
 
 
 
 
 614
 615	dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
 616	     inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
 617	     ceph_cap_string(issued|cap->issued), seq, mds);
 618	cap->cap_id = cap_id;
 619	cap->issued = issued;
 620	cap->implemented |= issued;
 621	cap->mds_wanted |= wanted;
 
 
 
 622	cap->seq = seq;
 623	cap->issue_seq = seq;
 624	cap->mseq = mseq;
 625	cap->cap_gen = session->s_cap_gen;
 626
 627	if (fmode >= 0)
 628		__ceph_get_fmode(ci, fmode);
 629	spin_unlock(&ci->i_ceph_lock);
 630	wake_up_all(&ci->i_cap_wq);
 631	return 0;
 632}
 633
 634/*
 635 * Return true if cap has not timed out and belongs to the current
 636 * generation of the MDS session (i.e. has not gone 'stale' due to
 637 * us losing touch with the mds).
 638 */
 639static int __cap_is_valid(struct ceph_cap *cap)
 640{
 641	unsigned long ttl;
 642	u32 gen;
 643
 644	spin_lock(&cap->session->s_gen_ttl_lock);
 645	gen = cap->session->s_cap_gen;
 646	ttl = cap->session->s_cap_ttl;
 647	spin_unlock(&cap->session->s_gen_ttl_lock);
 648
 649	if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
 650		dout("__cap_is_valid %p cap %p issued %s "
 651		     "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
 652		     cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
 653		return 0;
 654	}
 655
 656	return 1;
 657}
 658
 659/*
 660 * Return set of valid cap bits issued to us.  Note that caps time
 661 * out, and may be invalidated in bulk if the client session times out
 662 * and session->s_cap_gen is bumped.
 663 */
 664int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
 665{
 666	int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
 667	struct ceph_cap *cap;
 668	struct rb_node *p;
 669
 670	if (implemented)
 671		*implemented = 0;
 672	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 673		cap = rb_entry(p, struct ceph_cap, ci_node);
 674		if (!__cap_is_valid(cap))
 675			continue;
 676		dout("__ceph_caps_issued %p cap %p issued %s\n",
 677		     &ci->vfs_inode, cap, ceph_cap_string(cap->issued));
 678		have |= cap->issued;
 679		if (implemented)
 680			*implemented |= cap->implemented;
 681	}
 
 
 
 
 
 
 
 
 
 682	return have;
 683}
 684
 685/*
 686 * Get cap bits issued by caps other than @ocap
 687 */
 688int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
 689{
 690	int have = ci->i_snap_caps;
 691	struct ceph_cap *cap;
 692	struct rb_node *p;
 693
 694	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 695		cap = rb_entry(p, struct ceph_cap, ci_node);
 696		if (cap == ocap)
 697			continue;
 698		if (!__cap_is_valid(cap))
 699			continue;
 700		have |= cap->issued;
 701	}
 702	return have;
 703}
 704
 705/*
 706 * Move a cap to the end of the LRU (oldest caps at list head, newest
 707 * at list tail).
 708 */
 709static void __touch_cap(struct ceph_cap *cap)
 710{
 711	struct ceph_mds_session *s = cap->session;
 712
 713	spin_lock(&s->s_cap_lock);
 714	if (s->s_cap_iterator == NULL) {
 715		dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
 716		     s->s_mds);
 717		list_move_tail(&cap->session_caps, &s->s_caps);
 718	} else {
 719		dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
 720		     &cap->ci->vfs_inode, cap, s->s_mds);
 721	}
 722	spin_unlock(&s->s_cap_lock);
 723}
 724
 725/*
 726 * Check if we hold the given mask.  If so, move the cap(s) to the
 727 * front of their respective LRUs.  (This is the preferred way for
 728 * callers to check for caps they want.)
 729 */
 730int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
 731{
 732	struct ceph_cap *cap;
 733	struct rb_node *p;
 734	int have = ci->i_snap_caps;
 735
 736	if ((have & mask) == mask) {
 737		dout("__ceph_caps_issued_mask %p snap issued %s"
 738		     " (mask %s)\n", &ci->vfs_inode,
 739		     ceph_cap_string(have),
 740		     ceph_cap_string(mask));
 741		return 1;
 742	}
 743
 744	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 745		cap = rb_entry(p, struct ceph_cap, ci_node);
 746		if (!__cap_is_valid(cap))
 747			continue;
 748		if ((cap->issued & mask) == mask) {
 749			dout("__ceph_caps_issued_mask %p cap %p issued %s"
 750			     " (mask %s)\n", &ci->vfs_inode, cap,
 751			     ceph_cap_string(cap->issued),
 752			     ceph_cap_string(mask));
 753			if (touch)
 754				__touch_cap(cap);
 755			return 1;
 756		}
 757
 758		/* does a combination of caps satisfy mask? */
 759		have |= cap->issued;
 760		if ((have & mask) == mask) {
 761			dout("__ceph_caps_issued_mask %p combo issued %s"
 762			     " (mask %s)\n", &ci->vfs_inode,
 763			     ceph_cap_string(cap->issued),
 764			     ceph_cap_string(mask));
 765			if (touch) {
 766				struct rb_node *q;
 767
 768				/* touch this + preceding caps */
 769				__touch_cap(cap);
 770				for (q = rb_first(&ci->i_caps); q != p;
 771				     q = rb_next(q)) {
 772					cap = rb_entry(q, struct ceph_cap,
 773						       ci_node);
 774					if (!__cap_is_valid(cap))
 775						continue;
 776					__touch_cap(cap);
 777				}
 778			}
 779			return 1;
 780		}
 781	}
 782
 783	return 0;
 784}
 785
 786/*
 787 * Return true if mask caps are currently being revoked by an MDS.
 788 */
 789int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
 
 790{
 791	struct inode *inode = &ci->vfs_inode;
 792	struct ceph_cap *cap;
 793	struct rb_node *p;
 794	int ret = 0;
 795
 796	spin_lock(&ci->i_ceph_lock);
 797	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 798		cap = rb_entry(p, struct ceph_cap, ci_node);
 799		if (__cap_is_valid(cap) &&
 800		    (cap->implemented & ~cap->issued & mask)) {
 801			ret = 1;
 802			break;
 803		}
 804	}
 
 
 
 
 
 
 
 
 
 
 805	spin_unlock(&ci->i_ceph_lock);
 806	dout("ceph_caps_revoking %p %s = %d\n", inode,
 807	     ceph_cap_string(mask), ret);
 808	return ret;
 809}
 810
 811int __ceph_caps_used(struct ceph_inode_info *ci)
 812{
 813	int used = 0;
 814	if (ci->i_pin_ref)
 815		used |= CEPH_CAP_PIN;
 816	if (ci->i_rd_ref)
 817		used |= CEPH_CAP_FILE_RD;
 818	if (ci->i_rdcache_ref || ci->vfs_inode.i_data.nrpages)
 819		used |= CEPH_CAP_FILE_CACHE;
 820	if (ci->i_wr_ref)
 821		used |= CEPH_CAP_FILE_WR;
 822	if (ci->i_wb_ref || ci->i_wrbuffer_ref)
 823		used |= CEPH_CAP_FILE_BUFFER;
 824	return used;
 825}
 826
 827/*
 828 * wanted, by virtue of open file modes
 829 */
 830int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
 831{
 832	int want = 0;
 833	int mode;
 834	for (mode = 0; mode < CEPH_FILE_MODE_NUM; mode++)
 835		if (ci->i_nr_by_mode[mode])
 836			want |= ceph_caps_for_mode(mode);
 837	return want;
 838}
 839
 840/*
 841 * Return caps we have registered with the MDS(s) as 'wanted'.
 842 */
 843int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
 844{
 845	struct ceph_cap *cap;
 846	struct rb_node *p;
 847	int mds_wanted = 0;
 848
 849	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
 850		cap = rb_entry(p, struct ceph_cap, ci_node);
 851		if (!__cap_is_valid(cap))
 852			continue;
 853		mds_wanted |= cap->mds_wanted;
 
 
 
 854	}
 855	return mds_wanted;
 856}
 857
 858/*
 859 * called under i_ceph_lock
 860 */
 861static int __ceph_is_any_caps(struct ceph_inode_info *ci)
 862{
 863	return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_mds >= 0;
 
 
 
 
 
 
 
 
 
 
 
 
 864}
 865
 866/*
 867 * Remove a cap.  Take steps to deal with a racing iterate_session_caps.
 868 *
 869 * caller should hold i_ceph_lock.
 870 * caller will not hold session s_mutex if called from destroy_inode.
 871 */
 872void __ceph_remove_cap(struct ceph_cap *cap)
 873{
 874	struct ceph_mds_session *session = cap->session;
 875	struct ceph_inode_info *ci = cap->ci;
 876	struct ceph_mds_client *mdsc =
 877		ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
 878	int removed = 0;
 879
 880	dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
 881
 882	/* remove from session list */
 883	spin_lock(&session->s_cap_lock);
 
 
 
 
 
 
 
 
 
 
 884	if (session->s_cap_iterator == cap) {
 885		/* not yet, we are iterating over this very cap */
 886		dout("__ceph_remove_cap  delaying %p removal from session %p\n",
 887		     cap, cap->session);
 888	} else {
 889		list_del_init(&cap->session_caps);
 890		session->s_nr_caps--;
 891		cap->session = NULL;
 892		removed = 1;
 893	}
 894	/* protect backpointer with s_cap_lock: see iterate_session_caps */
 895	cap->ci = NULL;
 896	spin_unlock(&session->s_cap_lock);
 897
 898	/* remove from inode list */
 899	rb_erase(&cap->ci_node, &ci->i_caps);
 900	if (ci->i_auth_cap == cap)
 901		ci->i_auth_cap = NULL;
 902
 903	if (removed)
 904		ceph_put_cap(mdsc, cap);
 905
 906	if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
 907		struct ceph_snap_realm *realm = ci->i_snap_realm;
 908		spin_lock(&realm->inodes_with_caps_lock);
 909		list_del_init(&ci->i_snap_realm_item);
 910		ci->i_snap_realm_counter++;
 911		ci->i_snap_realm = NULL;
 912		spin_unlock(&realm->inodes_with_caps_lock);
 913		ceph_put_snap_realm(mdsc, realm);
 914	}
 915	if (!__ceph_is_any_real_caps(ci))
 916		__cap_delay_cancel(mdsc, ci);
 917}
 918
 919/*
 920 * Build and send a cap message to the given MDS.
 921 *
 922 * Caller should be holding s_mutex.
 923 */
 924static int send_cap_msg(struct ceph_mds_session *session,
 925			u64 ino, u64 cid, int op,
 926			int caps, int wanted, int dirty,
 927			u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq,
 928			u64 size, u64 max_size,
 929			struct timespec *mtime, struct timespec *atime,
 930			u64 time_warp_seq,
 931			uid_t uid, gid_t gid, umode_t mode,
 932			u64 xattr_version,
 933			struct ceph_buffer *xattrs_buf,
 934			u64 follows)
 935{
 936	struct ceph_mds_caps *fc;
 937	struct ceph_msg *msg;
 938
 939	dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
 940	     " seq %u/%u mseq %u follows %lld size %llu/%llu"
 941	     " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op),
 942	     cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
 943	     ceph_cap_string(dirty),
 944	     seq, issue_seq, mseq, follows, size, max_size,
 945	     xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
 946
 947	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), GFP_NOFS, false);
 948	if (!msg)
 949		return -ENOMEM;
 950
 951	msg->hdr.tid = cpu_to_le64(flush_tid);
 952
 953	fc = msg->front.iov_base;
 954	memset(fc, 0, sizeof(*fc));
 955
 956	fc->cap_id = cpu_to_le64(cid);
 957	fc->op = cpu_to_le32(op);
 958	fc->seq = cpu_to_le32(seq);
 959	fc->issue_seq = cpu_to_le32(issue_seq);
 960	fc->migrate_seq = cpu_to_le32(mseq);
 961	fc->caps = cpu_to_le32(caps);
 962	fc->wanted = cpu_to_le32(wanted);
 963	fc->dirty = cpu_to_le32(dirty);
 964	fc->ino = cpu_to_le64(ino);
 965	fc->snap_follows = cpu_to_le64(follows);
 966
 967	fc->size = cpu_to_le64(size);
 968	fc->max_size = cpu_to_le64(max_size);
 969	if (mtime)
 970		ceph_encode_timespec(&fc->mtime, mtime);
 971	if (atime)
 972		ceph_encode_timespec(&fc->atime, atime);
 973	fc->time_warp_seq = cpu_to_le32(time_warp_seq);
 974
 975	fc->uid = cpu_to_le32(uid);
 976	fc->gid = cpu_to_le32(gid);
 977	fc->mode = cpu_to_le32(mode);
 978
 979	fc->xattr_version = cpu_to_le64(xattr_version);
 980	if (xattrs_buf) {
 981		msg->middle = ceph_buffer_get(xattrs_buf);
 982		fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len);
 983		msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len);
 984	}
 985
 986	ceph_con_send(&session->s_con, msg);
 987	return 0;
 988}
 989
 990static void __queue_cap_release(struct ceph_mds_session *session,
 991				u64 ino, u64 cap_id, u32 migrate_seq,
 992				u32 issue_seq)
 993{
 994	struct ceph_msg *msg;
 995	struct ceph_mds_cap_release *head;
 996	struct ceph_mds_cap_item *item;
 997
 998	spin_lock(&session->s_cap_lock);
 999	BUG_ON(!session->s_num_cap_releases);
1000	msg = list_first_entry(&session->s_cap_releases,
1001			       struct ceph_msg, list_head);
1002
1003	dout(" adding %llx release to mds%d msg %p (%d left)\n",
1004	     ino, session->s_mds, msg, session->s_num_cap_releases);
1005
1006	BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
1007	head = msg->front.iov_base;
1008	head->num = cpu_to_le32(le32_to_cpu(head->num) + 1);
1009	item = msg->front.iov_base + msg->front.iov_len;
1010	item->ino = cpu_to_le64(ino);
1011	item->cap_id = cpu_to_le64(cap_id);
1012	item->migrate_seq = cpu_to_le32(migrate_seq);
1013	item->seq = cpu_to_le32(issue_seq);
1014
1015	session->s_num_cap_releases--;
1016
1017	msg->front.iov_len += sizeof(*item);
1018	if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1019		dout(" release msg %p full\n", msg);
1020		list_move_tail(&msg->list_head, &session->s_cap_releases_done);
1021	} else {
1022		dout(" release msg %p at %d/%d (%d)\n", msg,
1023		     (int)le32_to_cpu(head->num),
1024		     (int)CEPH_CAPS_PER_RELEASE,
1025		     (int)msg->front.iov_len);
1026	}
1027	spin_unlock(&session->s_cap_lock);
1028}
1029
1030/*
1031 * Queue cap releases when an inode is dropped from our cache.  Since
1032 * inode is about to be destroyed, there is no need for i_ceph_lock.
1033 */
1034void ceph_queue_caps_release(struct inode *inode)
1035{
1036	struct ceph_inode_info *ci = ceph_inode(inode);
1037	struct rb_node *p;
1038
1039	p = rb_first(&ci->i_caps);
1040	while (p) {
1041		struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
1042		struct ceph_mds_session *session = cap->session;
1043
1044		__queue_cap_release(session, ceph_ino(inode), cap->cap_id,
1045				    cap->mseq, cap->issue_seq);
1046		p = rb_next(p);
1047		__ceph_remove_cap(cap);
1048	}
1049}
1050
1051/*
1052 * Send a cap msg on the given inode.  Update our caps state, then
1053 * drop i_ceph_lock and send the message.
1054 *
1055 * Make note of max_size reported/requested from mds, revoked caps
1056 * that have now been implemented.
1057 *
1058 * Make half-hearted attempt ot to invalidate page cache if we are
1059 * dropping RDCACHE.  Note that this will leave behind locked pages
1060 * that we'll then need to deal with elsewhere.
1061 *
1062 * Return non-zero if delayed release, or we experienced an error
1063 * such that the caller should requeue + retry later.
1064 *
1065 * called with i_ceph_lock, then drops it.
1066 * caller should hold snap_rwsem (read), s_mutex.
1067 */
1068static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
1069		      int op, int used, int want, int retain, int flushing,
1070		      unsigned *pflush_tid)
1071	__releases(cap->ci->i_ceph_lock)
1072{
1073	struct ceph_inode_info *ci = cap->ci;
1074	struct inode *inode = &ci->vfs_inode;
1075	u64 cap_id = cap->cap_id;
1076	int held, revoking, dropping, keep;
1077	u64 seq, issue_seq, mseq, time_warp_seq, follows;
1078	u64 size, max_size;
1079	struct timespec mtime, atime;
1080	int wake = 0;
1081	umode_t mode;
1082	uid_t uid;
1083	gid_t gid;
1084	struct ceph_mds_session *session;
1085	u64 xattr_version = 0;
1086	struct ceph_buffer *xattr_blob = NULL;
1087	int delayed = 0;
1088	u64 flush_tid = 0;
1089	int i;
1090	int ret;
1091
1092	held = cap->issued | cap->implemented;
1093	revoking = cap->implemented & ~cap->issued;
1094	retain &= ~revoking;
1095	dropping = cap->issued & ~retain;
1096
1097	dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
1098	     inode, cap, cap->session,
1099	     ceph_cap_string(held), ceph_cap_string(held & retain),
1100	     ceph_cap_string(revoking));
1101	BUG_ON((retain & CEPH_CAP_PIN) == 0);
1102
1103	session = cap->session;
1104
1105	/* don't release wanted unless we've waited a bit. */
1106	if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1107	    time_before(jiffies, ci->i_hold_caps_min)) {
1108		dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
1109		     ceph_cap_string(cap->issued),
1110		     ceph_cap_string(cap->issued & retain),
1111		     ceph_cap_string(cap->mds_wanted),
1112		     ceph_cap_string(want));
1113		want |= cap->mds_wanted;
1114		retain |= cap->issued;
1115		delayed = 1;
1116	}
1117	ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
1118
1119	cap->issued &= retain;  /* drop bits we don't want */
1120	if (cap->implemented & ~cap->issued) {
1121		/*
1122		 * Wake up any waiters on wanted -> needed transition.
1123		 * This is due to the weird transition from buffered
1124		 * to sync IO... we need to flush dirty pages _before_
1125		 * allowing sync writes to avoid reordering.
1126		 */
1127		wake = 1;
1128	}
1129	cap->implemented &= cap->issued | used;
1130	cap->mds_wanted = want;
1131
1132	if (flushing) {
1133		/*
1134		 * assign a tid for flush operations so we can avoid
1135		 * flush1 -> dirty1 -> flush2 -> flushack1 -> mark
1136		 * clean type races.  track latest tid for every bit
1137		 * so we can handle flush AxFw, flush Fw, and have the
1138		 * first ack clean Ax.
1139		 */
1140		flush_tid = ++ci->i_cap_flush_last_tid;
1141		if (pflush_tid)
1142			*pflush_tid = flush_tid;
1143		dout(" cap_flush_tid %d\n", (int)flush_tid);
1144		for (i = 0; i < CEPH_CAP_BITS; i++)
1145			if (flushing & (1 << i))
1146				ci->i_cap_flush_tid[i] = flush_tid;
1147
1148		follows = ci->i_head_snapc->seq;
1149	} else {
1150		follows = 0;
1151	}
1152
1153	keep = cap->implemented;
1154	seq = cap->seq;
1155	issue_seq = cap->issue_seq;
1156	mseq = cap->mseq;
1157	size = inode->i_size;
1158	ci->i_reported_size = size;
1159	max_size = ci->i_wanted_max_size;
1160	ci->i_requested_max_size = max_size;
1161	mtime = inode->i_mtime;
1162	atime = inode->i_atime;
1163	time_warp_seq = ci->i_time_warp_seq;
1164	uid = inode->i_uid;
1165	gid = inode->i_gid;
1166	mode = inode->i_mode;
1167
1168	if (flushing & CEPH_CAP_XATTR_EXCL) {
1169		__ceph_build_xattrs_blob(ci);
1170		xattr_blob = ci->i_xattrs.blob;
1171		xattr_version = ci->i_xattrs.version;
1172	}
1173
1174	spin_unlock(&ci->i_ceph_lock);
1175
1176	ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
1177		op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
1178		size, max_size, &mtime, &atime, time_warp_seq,
1179		uid, gid, mode, xattr_version, xattr_blob,
1180		follows);
1181	if (ret < 0) {
1182		dout("error sending cap msg, must requeue %p\n", inode);
1183		delayed = 1;
1184	}
1185
1186	if (wake)
1187		wake_up_all(&ci->i_cap_wq);
1188
1189	return delayed;
1190}
1191
1192/*
1193 * When a snapshot is taken, clients accumulate dirty metadata on
1194 * inodes with capabilities in ceph_cap_snaps to describe the file
1195 * state at the time the snapshot was taken.  This must be flushed
1196 * asynchronously back to the MDS once sync writes complete and dirty
1197 * data is written out.
1198 *
1199 * Unless @again is true, skip cap_snaps that were already sent to
1200 * the MDS (i.e., during this session).
1201 *
1202 * Called under i_ceph_lock.  Takes s_mutex as needed.
1203 */
1204void __ceph_flush_snaps(struct ceph_inode_info *ci,
1205			struct ceph_mds_session **psession,
1206			int again)
1207		__releases(ci->i_ceph_lock)
1208		__acquires(ci->i_ceph_lock)
1209{
1210	struct inode *inode = &ci->vfs_inode;
1211	int mds;
1212	struct ceph_cap_snap *capsnap;
1213	u32 mseq;
1214	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1215	struct ceph_mds_session *session = NULL; /* if session != NULL, we hold
1216						    session->s_mutex */
1217	u64 next_follows = 0;  /* keep track of how far we've gotten through the
1218			     i_cap_snaps list, and skip these entries next time
1219			     around to avoid an infinite loop */
1220
1221	if (psession)
1222		session = *psession;
1223
1224	dout("__flush_snaps %p\n", inode);
1225retry:
1226	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
1227		/* avoid an infiniute loop after retry */
1228		if (capsnap->follows < next_follows)
1229			continue;
1230		/*
1231		 * we need to wait for sync writes to complete and for dirty
1232		 * pages to be written out.
1233		 */
1234		if (capsnap->dirty_pages || capsnap->writing)
1235			break;
1236
1237		/*
1238		 * if cap writeback already occurred, we should have dropped
1239		 * the capsnap in ceph_put_wrbuffer_cap_refs.
1240		 */
1241		BUG_ON(capsnap->dirty == 0);
1242
1243		/* pick mds, take s_mutex */
1244		if (ci->i_auth_cap == NULL) {
1245			dout("no auth cap (migrating?), doing nothing\n");
1246			goto out;
1247		}
1248
1249		/* only flush each capsnap once */
1250		if (!again && !list_empty(&capsnap->flushing_item)) {
1251			dout("already flushed %p, skipping\n", capsnap);
1252			continue;
1253		}
1254
1255		mds = ci->i_auth_cap->session->s_mds;
1256		mseq = ci->i_auth_cap->mseq;
1257
1258		if (session && session->s_mds != mds) {
1259			dout("oops, wrong session %p mutex\n", session);
1260			mutex_unlock(&session->s_mutex);
1261			ceph_put_mds_session(session);
1262			session = NULL;
1263		}
1264		if (!session) {
1265			spin_unlock(&ci->i_ceph_lock);
1266			mutex_lock(&mdsc->mutex);
1267			session = __ceph_lookup_mds_session(mdsc, mds);
1268			mutex_unlock(&mdsc->mutex);
1269			if (session) {
1270				dout("inverting session/ino locks on %p\n",
1271				     session);
1272				mutex_lock(&session->s_mutex);
1273			}
1274			/*
1275			 * if session == NULL, we raced against a cap
1276			 * deletion or migration.  retry, and we'll
1277			 * get a better @mds value next time.
1278			 */
1279			spin_lock(&ci->i_ceph_lock);
1280			goto retry;
1281		}
1282
1283		capsnap->flush_tid = ++ci->i_cap_flush_last_tid;
1284		atomic_inc(&capsnap->nref);
1285		if (!list_empty(&capsnap->flushing_item))
1286			list_del_init(&capsnap->flushing_item);
1287		list_add_tail(&capsnap->flushing_item,
1288			      &session->s_cap_snaps_flushing);
1289		spin_unlock(&ci->i_ceph_lock);
1290
1291		dout("flush_snaps %p cap_snap %p follows %lld tid %llu\n",
1292		     inode, capsnap, capsnap->follows, capsnap->flush_tid);
1293		send_cap_msg(session, ceph_vino(inode).ino, 0,
1294			     CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
1295			     capsnap->dirty, 0, capsnap->flush_tid, 0, mseq,
1296			     capsnap->size, 0,
1297			     &capsnap->mtime, &capsnap->atime,
1298			     capsnap->time_warp_seq,
1299			     capsnap->uid, capsnap->gid, capsnap->mode,
1300			     capsnap->xattr_version, capsnap->xattr_blob,
1301			     capsnap->follows);
1302
1303		next_follows = capsnap->follows + 1;
1304		ceph_put_cap_snap(capsnap);
1305
1306		spin_lock(&ci->i_ceph_lock);
1307		goto retry;
1308	}
1309
1310	/* we flushed them all; remove this inode from the queue */
1311	spin_lock(&mdsc->snap_flush_lock);
1312	list_del_init(&ci->i_snap_flush_item);
1313	spin_unlock(&mdsc->snap_flush_lock);
1314
1315out:
1316	if (psession)
1317		*psession = session;
1318	else if (session) {
1319		mutex_unlock(&session->s_mutex);
1320		ceph_put_mds_session(session);
1321	}
1322}
1323
1324static void ceph_flush_snaps(struct ceph_inode_info *ci)
1325{
1326	spin_lock(&ci->i_ceph_lock);
1327	__ceph_flush_snaps(ci, NULL, 0);
1328	spin_unlock(&ci->i_ceph_lock);
1329}
1330
1331/*
1332 * Mark caps dirty.  If inode is newly dirty, return the dirty flags.
1333 * Caller is then responsible for calling __mark_inode_dirty with the
1334 * returned flags value.
1335 */
1336int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
1337{
1338	struct ceph_mds_client *mdsc =
1339		ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
1340	struct inode *inode = &ci->vfs_inode;
1341	int was = ci->i_dirty_caps;
1342	int dirty = 0;
1343
1344	dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
1345	     ceph_cap_string(mask), ceph_cap_string(was),
1346	     ceph_cap_string(was | mask));
1347	ci->i_dirty_caps |= mask;
1348	if (was == 0) {
1349		if (!ci->i_head_snapc)
1350			ci->i_head_snapc = ceph_get_snap_context(
1351				ci->i_snap_realm->cached_context);
1352		dout(" inode %p now dirty snapc %p\n", &ci->vfs_inode,
1353			ci->i_head_snapc);
 
1354		BUG_ON(!list_empty(&ci->i_dirty_item));
1355		spin_lock(&mdsc->cap_dirty_lock);
1356		list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
1357		spin_unlock(&mdsc->cap_dirty_lock);
1358		if (ci->i_flushing_caps == 0) {
1359			ihold(inode);
1360			dirty |= I_DIRTY_SYNC;
1361		}
1362	}
1363	BUG_ON(list_empty(&ci->i_dirty_item));
1364	if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
1365	    (mask & CEPH_CAP_FILE_BUFFER))
1366		dirty |= I_DIRTY_DATASYNC;
1367	__cap_delay_requeue(mdsc, ci);
1368	return dirty;
1369}
1370
1371/*
1372 * Add dirty inode to the flushing list.  Assigned a seq number so we
1373 * can wait for caps to flush without starving.
1374 *
1375 * Called under i_ceph_lock.
1376 */
1377static int __mark_caps_flushing(struct inode *inode,
1378				 struct ceph_mds_session *session)
1379{
1380	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1381	struct ceph_inode_info *ci = ceph_inode(inode);
1382	int flushing;
1383
1384	BUG_ON(ci->i_dirty_caps == 0);
1385	BUG_ON(list_empty(&ci->i_dirty_item));
1386
1387	flushing = ci->i_dirty_caps;
1388	dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
1389	     ceph_cap_string(flushing),
1390	     ceph_cap_string(ci->i_flushing_caps),
1391	     ceph_cap_string(ci->i_flushing_caps | flushing));
1392	ci->i_flushing_caps |= flushing;
1393	ci->i_dirty_caps = 0;
1394	dout(" inode %p now !dirty\n", inode);
1395
1396	spin_lock(&mdsc->cap_dirty_lock);
1397	list_del_init(&ci->i_dirty_item);
1398
1399	ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
1400	if (list_empty(&ci->i_flushing_item)) {
1401		list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1402		mdsc->num_cap_flushing++;
1403		dout(" inode %p now flushing seq %lld\n", inode,
1404		     ci->i_cap_flush_seq);
1405	} else {
1406		list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1407		dout(" inode %p now flushing (more) seq %lld\n", inode,
1408		     ci->i_cap_flush_seq);
1409	}
1410	spin_unlock(&mdsc->cap_dirty_lock);
1411
1412	return flushing;
1413}
1414
1415/*
1416 * try to invalidate mapping pages without blocking.
1417 */
1418static int try_nonblocking_invalidate(struct inode *inode)
1419{
1420	struct ceph_inode_info *ci = ceph_inode(inode);
1421	u32 invalidating_gen = ci->i_rdcache_gen;
1422
1423	spin_unlock(&ci->i_ceph_lock);
1424	invalidate_mapping_pages(&inode->i_data, 0, -1);
1425	spin_lock(&ci->i_ceph_lock);
1426
1427	if (inode->i_data.nrpages == 0 &&
1428	    invalidating_gen == ci->i_rdcache_gen) {
1429		/* success. */
1430		dout("try_nonblocking_invalidate %p success\n", inode);
1431		/* save any racing async invalidate some trouble */
1432		ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
1433		return 0;
1434	}
1435	dout("try_nonblocking_invalidate %p failed\n", inode);
1436	return -1;
1437}
1438
1439/*
1440 * Swiss army knife function to examine currently used and wanted
1441 * versus held caps.  Release, flush, ack revoked caps to mds as
1442 * appropriate.
1443 *
1444 *  CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
1445 *    cap release further.
1446 *  CHECK_CAPS_AUTHONLY - we should only check the auth cap
1447 *  CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
1448 *    further delay.
1449 */
1450void ceph_check_caps(struct ceph_inode_info *ci, int flags,
1451		     struct ceph_mds_session *session)
1452{
1453	struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1454	struct ceph_mds_client *mdsc = fsc->mdsc;
1455	struct inode *inode = &ci->vfs_inode;
1456	struct ceph_cap *cap;
1457	int file_wanted, used;
1458	int took_snap_rwsem = 0;             /* true if mdsc->snap_rwsem held */
1459	int issued, implemented, want, retain, revoking, flushing = 0;
1460	int mds = -1;   /* keep track of how far we've gone through i_caps list
1461			   to avoid an infinite loop on retry */
1462	struct rb_node *p;
1463	int tried_invalidate = 0;
1464	int delayed = 0, sent = 0, force_requeue = 0, num;
1465	int queue_invalidate = 0;
1466	int is_delayed = flags & CHECK_CAPS_NODELAY;
1467
1468	/* if we are unmounting, flush any unused caps immediately. */
1469	if (mdsc->stopping)
1470		is_delayed = 1;
1471
1472	spin_lock(&ci->i_ceph_lock);
1473
1474	if (ci->i_ceph_flags & CEPH_I_FLUSH)
1475		flags |= CHECK_CAPS_FLUSH;
1476
1477	/* flush snaps first time around only */
1478	if (!list_empty(&ci->i_cap_snaps))
1479		__ceph_flush_snaps(ci, &session, 0);
1480	goto retry_locked;
1481retry:
1482	spin_lock(&ci->i_ceph_lock);
1483retry_locked:
1484	file_wanted = __ceph_caps_file_wanted(ci);
1485	used = __ceph_caps_used(ci);
1486	want = file_wanted | used;
1487	issued = __ceph_caps_issued(ci, &implemented);
1488	revoking = implemented & ~issued;
1489
1490	retain = want | CEPH_CAP_PIN;
1491	if (!mdsc->stopping && inode->i_nlink > 0) {
1492		if (want) {
1493			retain |= CEPH_CAP_ANY;       /* be greedy */
1494		} else {
1495			retain |= CEPH_CAP_ANY_SHARED;
1496			/*
1497			 * keep RD only if we didn't have the file open RW,
1498			 * because then the mds would revoke it anyway to
1499			 * journal max_size=0.
1500			 */
1501			if (ci->i_max_size == 0)
1502				retain |= CEPH_CAP_ANY_RD;
1503		}
1504	}
1505
1506	dout("check_caps %p file_want %s used %s dirty %s flushing %s"
1507	     " issued %s revoking %s retain %s %s%s%s\n", inode,
1508	     ceph_cap_string(file_wanted),
1509	     ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
1510	     ceph_cap_string(ci->i_flushing_caps),
1511	     ceph_cap_string(issued), ceph_cap_string(revoking),
1512	     ceph_cap_string(retain),
1513	     (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
1514	     (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
1515	     (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
1516
1517	/*
1518	 * If we no longer need to hold onto old our caps, and we may
1519	 * have cached pages, but don't want them, then try to invalidate.
1520	 * If we fail, it's because pages are locked.... try again later.
1521	 */
1522	if ((!is_delayed || mdsc->stopping) &&
1523	    ci->i_wrbuffer_ref == 0 &&               /* no dirty pages... */
1524	    inode->i_data.nrpages &&                 /* have cached pages */
1525	    (file_wanted == 0 ||                     /* no open files */
1526	     (revoking & (CEPH_CAP_FILE_CACHE|
1527			  CEPH_CAP_FILE_LAZYIO))) && /*  or revoking cache */
1528	    !tried_invalidate) {
1529		dout("check_caps trying to invalidate on %p\n", inode);
1530		if (try_nonblocking_invalidate(inode) < 0) {
1531			if (revoking & (CEPH_CAP_FILE_CACHE|
1532					CEPH_CAP_FILE_LAZYIO)) {
1533				dout("check_caps queuing invalidate\n");
1534				queue_invalidate = 1;
1535				ci->i_rdcache_revoking = ci->i_rdcache_gen;
1536			} else {
1537				dout("check_caps failed to invalidate pages\n");
1538				/* we failed to invalidate pages.  check these
1539				   caps again later. */
1540				force_requeue = 1;
1541				__cap_set_timeouts(mdsc, ci);
1542			}
1543		}
1544		tried_invalidate = 1;
1545		goto retry_locked;
1546	}
1547
1548	num = 0;
1549	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
1550		cap = rb_entry(p, struct ceph_cap, ci_node);
1551		num++;
1552
1553		/* avoid looping forever */
1554		if (mds >= cap->mds ||
1555		    ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
1556			continue;
1557
1558		/* NOTE: no side-effects allowed, until we take s_mutex */
1559
 
 
 
 
1560		revoking = cap->implemented & ~cap->issued;
1561		dout(" mds%d cap %p issued %s implemented %s revoking %s\n",
1562		     cap->mds, cap, ceph_cap_string(cap->issued),
 
1563		     ceph_cap_string(cap->implemented),
1564		     ceph_cap_string(revoking));
1565
1566		if (cap == ci->i_auth_cap &&
1567		    (cap->issued & CEPH_CAP_FILE_WR)) {
1568			/* request larger max_size from MDS? */
1569			if (ci->i_wanted_max_size > ci->i_max_size &&
1570			    ci->i_wanted_max_size > ci->i_requested_max_size) {
1571				dout("requesting new max_size\n");
1572				goto ack;
1573			}
1574
1575			/* approaching file_max? */
1576			if ((inode->i_size << 1) >= ci->i_max_size &&
1577			    (ci->i_reported_size << 1) < ci->i_max_size) {
1578				dout("i_size approaching max_size\n");
1579				goto ack;
1580			}
1581		}
1582		/* flush anything dirty? */
1583		if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) &&
1584		    ci->i_dirty_caps) {
1585			dout("flushing dirty caps\n");
1586			goto ack;
1587		}
1588
1589		/* completed revocation? going down and there are no caps? */
1590		if (revoking && (revoking & used) == 0) {
1591			dout("completed revocation of %s\n",
1592			     ceph_cap_string(cap->implemented & ~cap->issued));
1593			goto ack;
1594		}
1595
1596		/* want more caps from mds? */
1597		if (want & ~(cap->mds_wanted | cap->issued))
1598			goto ack;
1599
1600		/* things we might delay */
1601		if ((cap->issued & ~retain) == 0 &&
1602		    cap->mds_wanted == want)
1603			continue;     /* nope, all good */
1604
1605		if (is_delayed)
1606			goto ack;
1607
1608		/* delay? */
1609		if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1610		    time_before(jiffies, ci->i_hold_caps_max)) {
1611			dout(" delaying issued %s -> %s, wanted %s -> %s\n",
1612			     ceph_cap_string(cap->issued),
1613			     ceph_cap_string(cap->issued & retain),
1614			     ceph_cap_string(cap->mds_wanted),
1615			     ceph_cap_string(want));
1616			delayed++;
1617			continue;
1618		}
1619
1620ack:
1621		if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1622			dout(" skipping %p I_NOFLUSH set\n", inode);
1623			continue;
1624		}
1625
1626		if (session && session != cap->session) {
1627			dout("oops, wrong session %p mutex\n", session);
1628			mutex_unlock(&session->s_mutex);
1629			session = NULL;
1630		}
1631		if (!session) {
1632			session = cap->session;
1633			if (mutex_trylock(&session->s_mutex) == 0) {
1634				dout("inverting session/ino locks on %p\n",
1635				     session);
1636				spin_unlock(&ci->i_ceph_lock);
1637				if (took_snap_rwsem) {
1638					up_read(&mdsc->snap_rwsem);
1639					took_snap_rwsem = 0;
1640				}
1641				mutex_lock(&session->s_mutex);
1642				goto retry;
1643			}
1644		}
1645		/* take snap_rwsem after session mutex */
1646		if (!took_snap_rwsem) {
1647			if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
1648				dout("inverting snap/in locks on %p\n",
1649				     inode);
1650				spin_unlock(&ci->i_ceph_lock);
1651				down_read(&mdsc->snap_rwsem);
1652				took_snap_rwsem = 1;
1653				goto retry;
1654			}
1655			took_snap_rwsem = 1;
1656		}
1657
1658		if (cap == ci->i_auth_cap && ci->i_dirty_caps)
1659			flushing = __mark_caps_flushing(inode, session);
1660		else
1661			flushing = 0;
1662
1663		mds = cap->mds;  /* remember mds, so we don't repeat */
1664		sent++;
1665
1666		/* __send_cap drops i_ceph_lock */
1667		delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want,
1668				      retain, flushing, NULL);
1669		goto retry; /* retake i_ceph_lock and restart our cap scan. */
1670	}
1671
1672	/*
1673	 * Reschedule delayed caps release if we delayed anything,
1674	 * otherwise cancel.
1675	 */
1676	if (delayed && is_delayed)
1677		force_requeue = 1;   /* __send_cap delayed release; requeue */
1678	if (!delayed && !is_delayed)
1679		__cap_delay_cancel(mdsc, ci);
1680	else if (!is_delayed || force_requeue)
1681		__cap_delay_requeue(mdsc, ci);
1682
1683	spin_unlock(&ci->i_ceph_lock);
1684
1685	if (queue_invalidate)
1686		ceph_queue_invalidate(inode);
1687
1688	if (session)
1689		mutex_unlock(&session->s_mutex);
1690	if (took_snap_rwsem)
1691		up_read(&mdsc->snap_rwsem);
1692}
1693
1694/*
1695 * Try to flush dirty caps back to the auth mds.
1696 */
1697static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session,
1698			  unsigned *flush_tid)
1699{
1700	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1701	struct ceph_inode_info *ci = ceph_inode(inode);
1702	int unlock_session = session ? 0 : 1;
1703	int flushing = 0;
 
1704
1705retry:
1706	spin_lock(&ci->i_ceph_lock);
1707	if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1708		dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
1709		goto out;
1710	}
1711	if (ci->i_dirty_caps && ci->i_auth_cap) {
1712		struct ceph_cap *cap = ci->i_auth_cap;
1713		int used = __ceph_caps_used(ci);
1714		int want = __ceph_caps_wanted(ci);
1715		int delayed;
1716
1717		if (!session) {
1718			spin_unlock(&ci->i_ceph_lock);
 
 
1719			session = cap->session;
1720			mutex_lock(&session->s_mutex);
1721			goto retry;
1722		}
1723		BUG_ON(session != cap->session);
1724		if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
1725			goto out;
1726
1727		flushing = __mark_caps_flushing(inode, session);
1728
1729		/* __send_cap drops i_ceph_lock */
1730		delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
1731				     cap->issued | cap->implemented, flushing,
1732				     flush_tid);
1733		if (!delayed)
1734			goto out_unlocked;
1735
1736		spin_lock(&ci->i_ceph_lock);
1737		__cap_delay_requeue(mdsc, ci);
1738	}
1739out:
1740	spin_unlock(&ci->i_ceph_lock);
1741out_unlocked:
1742	if (session && unlock_session)
1743		mutex_unlock(&session->s_mutex);
1744	return flushing;
1745}
1746
1747/*
1748 * Return true if we've flushed caps through the given flush_tid.
1749 */
1750static int caps_are_flushed(struct inode *inode, unsigned tid)
1751{
1752	struct ceph_inode_info *ci = ceph_inode(inode);
1753	int i, ret = 1;
1754
1755	spin_lock(&ci->i_ceph_lock);
1756	for (i = 0; i < CEPH_CAP_BITS; i++)
1757		if ((ci->i_flushing_caps & (1 << i)) &&
1758		    ci->i_cap_flush_tid[i] <= tid) {
1759			/* still flushing this bit */
1760			ret = 0;
1761			break;
1762		}
1763	spin_unlock(&ci->i_ceph_lock);
1764	return ret;
1765}
1766
1767/*
1768 * Wait on any unsafe replies for the given inode.  First wait on the
1769 * newest request, and make that the upper bound.  Then, if there are
1770 * more requests, keep waiting on the oldest as long as it is still older
1771 * than the original request.
1772 */
1773static void sync_write_wait(struct inode *inode)
1774{
1775	struct ceph_inode_info *ci = ceph_inode(inode);
1776	struct list_head *head = &ci->i_unsafe_writes;
1777	struct ceph_osd_request *req;
1778	u64 last_tid;
1779
1780	spin_lock(&ci->i_unsafe_lock);
1781	if (list_empty(head))
1782		goto out;
1783
1784	/* set upper bound as _last_ entry in chain */
1785	req = list_entry(head->prev, struct ceph_osd_request,
1786			 r_unsafe_item);
1787	last_tid = req->r_tid;
1788
1789	do {
1790		ceph_osdc_get_request(req);
1791		spin_unlock(&ci->i_unsafe_lock);
1792		dout("sync_write_wait on tid %llu (until %llu)\n",
1793		     req->r_tid, last_tid);
1794		wait_for_completion(&req->r_safe_completion);
1795		spin_lock(&ci->i_unsafe_lock);
1796		ceph_osdc_put_request(req);
1797
1798		/*
1799		 * from here on look at first entry in chain, since we
1800		 * only want to wait for anything older than last_tid
1801		 */
1802		if (list_empty(head))
1803			break;
1804		req = list_entry(head->next, struct ceph_osd_request,
1805				 r_unsafe_item);
1806	} while (req->r_tid < last_tid);
1807out:
1808	spin_unlock(&ci->i_unsafe_lock);
1809}
1810
1811int ceph_fsync(struct file *file, loff_t start, loff_t end, int datasync)
1812{
1813	struct inode *inode = file->f_mapping->host;
1814	struct ceph_inode_info *ci = ceph_inode(inode);
1815	unsigned flush_tid;
1816	int ret;
1817	int dirty;
1818
1819	dout("fsync %p%s\n", inode, datasync ? " datasync" : "");
1820	sync_write_wait(inode);
1821
1822	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
1823	if (ret < 0)
1824		return ret;
1825	mutex_lock(&inode->i_mutex);
1826
1827	dirty = try_flush_caps(inode, NULL, &flush_tid);
1828	dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
1829
1830	/*
1831	 * only wait on non-file metadata writeback (the mds
1832	 * can recover size and mtime, so we don't need to
1833	 * wait for that)
1834	 */
1835	if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
1836		dout("fsync waiting for flush_tid %u\n", flush_tid);
1837		ret = wait_event_interruptible(ci->i_cap_wq,
1838				       caps_are_flushed(inode, flush_tid));
1839	}
1840
1841	dout("fsync %p%s done\n", inode, datasync ? " datasync" : "");
1842	mutex_unlock(&inode->i_mutex);
1843	return ret;
1844}
1845
1846/*
1847 * Flush any dirty caps back to the mds.  If we aren't asked to wait,
1848 * queue inode for flush but don't do so immediately, because we can
1849 * get by with fewer MDS messages if we wait for data writeback to
1850 * complete first.
1851 */
1852int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
1853{
1854	struct ceph_inode_info *ci = ceph_inode(inode);
1855	unsigned flush_tid;
1856	int err = 0;
1857	int dirty;
1858	int wait = wbc->sync_mode == WB_SYNC_ALL;
1859
1860	dout("write_inode %p wait=%d\n", inode, wait);
1861	if (wait) {
1862		dirty = try_flush_caps(inode, NULL, &flush_tid);
1863		if (dirty)
1864			err = wait_event_interruptible(ci->i_cap_wq,
1865				       caps_are_flushed(inode, flush_tid));
1866	} else {
1867		struct ceph_mds_client *mdsc =
1868			ceph_sb_to_client(inode->i_sb)->mdsc;
1869
1870		spin_lock(&ci->i_ceph_lock);
1871		if (__ceph_caps_dirty(ci))
1872			__cap_delay_requeue_front(mdsc, ci);
1873		spin_unlock(&ci->i_ceph_lock);
1874	}
1875	return err;
1876}
1877
1878/*
1879 * After a recovering MDS goes active, we need to resend any caps
1880 * we were flushing.
1881 *
1882 * Caller holds session->s_mutex.
1883 */
1884static void kick_flushing_capsnaps(struct ceph_mds_client *mdsc,
1885				   struct ceph_mds_session *session)
1886{
1887	struct ceph_cap_snap *capsnap;
1888
1889	dout("kick_flushing_capsnaps mds%d\n", session->s_mds);
1890	list_for_each_entry(capsnap, &session->s_cap_snaps_flushing,
1891			    flushing_item) {
1892		struct ceph_inode_info *ci = capsnap->ci;
1893		struct inode *inode = &ci->vfs_inode;
1894		struct ceph_cap *cap;
1895
1896		spin_lock(&ci->i_ceph_lock);
1897		cap = ci->i_auth_cap;
1898		if (cap && cap->session == session) {
1899			dout("kick_flushing_caps %p cap %p capsnap %p\n", inode,
1900			     cap, capsnap);
1901			__ceph_flush_snaps(ci, &session, 1);
1902		} else {
1903			pr_err("%p auth cap %p not mds%d ???\n", inode,
1904			       cap, session->s_mds);
1905		}
1906		spin_unlock(&ci->i_ceph_lock);
1907	}
1908}
1909
1910void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
1911			     struct ceph_mds_session *session)
1912{
1913	struct ceph_inode_info *ci;
1914
1915	kick_flushing_capsnaps(mdsc, session);
1916
1917	dout("kick_flushing_caps mds%d\n", session->s_mds);
1918	list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
1919		struct inode *inode = &ci->vfs_inode;
1920		struct ceph_cap *cap;
1921		int delayed = 0;
1922
1923		spin_lock(&ci->i_ceph_lock);
1924		cap = ci->i_auth_cap;
1925		if (cap && cap->session == session) {
1926			dout("kick_flushing_caps %p cap %p %s\n", inode,
1927			     cap, ceph_cap_string(ci->i_flushing_caps));
1928			delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
1929					     __ceph_caps_used(ci),
1930					     __ceph_caps_wanted(ci),
1931					     cap->issued | cap->implemented,
1932					     ci->i_flushing_caps, NULL);
1933			if (delayed) {
1934				spin_lock(&ci->i_ceph_lock);
1935				__cap_delay_requeue(mdsc, ci);
1936				spin_unlock(&ci->i_ceph_lock);
1937			}
1938		} else {
1939			pr_err("%p auth cap %p not mds%d ???\n", inode,
1940			       cap, session->s_mds);
1941			spin_unlock(&ci->i_ceph_lock);
1942		}
1943	}
1944}
1945
1946static void kick_flushing_inode_caps(struct ceph_mds_client *mdsc,
1947				     struct ceph_mds_session *session,
1948				     struct inode *inode)
1949{
1950	struct ceph_inode_info *ci = ceph_inode(inode);
1951	struct ceph_cap *cap;
1952	int delayed = 0;
1953
1954	spin_lock(&ci->i_ceph_lock);
1955	cap = ci->i_auth_cap;
1956	dout("kick_flushing_inode_caps %p flushing %s flush_seq %lld\n", inode,
1957	     ceph_cap_string(ci->i_flushing_caps), ci->i_cap_flush_seq);
 
1958	__ceph_flush_snaps(ci, &session, 1);
 
1959	if (ci->i_flushing_caps) {
 
 
 
 
 
1960		delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
1961				     __ceph_caps_used(ci),
1962				     __ceph_caps_wanted(ci),
1963				     cap->issued | cap->implemented,
1964				     ci->i_flushing_caps, NULL);
1965		if (delayed) {
1966			spin_lock(&ci->i_ceph_lock);
1967			__cap_delay_requeue(mdsc, ci);
1968			spin_unlock(&ci->i_ceph_lock);
1969		}
1970	} else {
1971		spin_unlock(&ci->i_ceph_lock);
1972	}
1973}
1974
1975
1976/*
1977 * Take references to capabilities we hold, so that we don't release
1978 * them to the MDS prematurely.
1979 *
1980 * Protected by i_ceph_lock.
1981 */
1982static void __take_cap_refs(struct ceph_inode_info *ci, int got)
1983{
1984	if (got & CEPH_CAP_PIN)
1985		ci->i_pin_ref++;
1986	if (got & CEPH_CAP_FILE_RD)
1987		ci->i_rd_ref++;
1988	if (got & CEPH_CAP_FILE_CACHE)
1989		ci->i_rdcache_ref++;
1990	if (got & CEPH_CAP_FILE_WR)
1991		ci->i_wr_ref++;
1992	if (got & CEPH_CAP_FILE_BUFFER) {
1993		if (ci->i_wb_ref == 0)
1994			ihold(&ci->vfs_inode);
1995		ci->i_wb_ref++;
1996		dout("__take_cap_refs %p wb %d -> %d (?)\n",
1997		     &ci->vfs_inode, ci->i_wb_ref-1, ci->i_wb_ref);
1998	}
1999}
2000
2001/*
2002 * Try to grab cap references.  Specify those refs we @want, and the
2003 * minimal set we @need.  Also include the larger offset we are writing
2004 * to (when applicable), and check against max_size here as well.
2005 * Note that caller is responsible for ensuring max_size increases are
2006 * requested from the MDS.
2007 */
2008static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
2009			    int *got, loff_t endoff, int *check_max, int *err)
2010{
2011	struct inode *inode = &ci->vfs_inode;
2012	int ret = 0;
2013	int have, implemented;
2014	int file_wanted;
2015
2016	dout("get_cap_refs %p need %s want %s\n", inode,
2017	     ceph_cap_string(need), ceph_cap_string(want));
2018	spin_lock(&ci->i_ceph_lock);
2019
2020	/* make sure file is actually open */
2021	file_wanted = __ceph_caps_file_wanted(ci);
2022	if ((file_wanted & need) == 0) {
2023		dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
2024		     ceph_cap_string(need), ceph_cap_string(file_wanted));
2025		*err = -EBADF;
2026		ret = 1;
2027		goto out;
2028	}
2029
2030	if (need & CEPH_CAP_FILE_WR) {
 
 
 
 
 
 
 
 
 
2031		if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
2032			dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
2033			     inode, endoff, ci->i_max_size);
2034			if (endoff > ci->i_wanted_max_size) {
2035				*check_max = 1;
2036				ret = 1;
2037			}
2038			goto out;
2039		}
2040		/*
2041		 * If a sync write is in progress, we must wait, so that we
2042		 * can get a final snapshot value for size+mtime.
2043		 */
2044		if (__ceph_have_pending_cap_snap(ci)) {
2045			dout("get_cap_refs %p cap_snap_pending\n", inode);
2046			goto out;
2047		}
2048	}
2049	have = __ceph_caps_issued(ci, &implemented);
2050
2051	/*
2052	 * disallow writes while a truncate is pending
2053	 */
2054	if (ci->i_truncate_pending)
2055		have &= ~CEPH_CAP_FILE_WR;
2056
2057	if ((have & need) == need) {
2058		/*
2059		 * Look at (implemented & ~have & not) so that we keep waiting
2060		 * on transition from wanted -> needed caps.  This is needed
2061		 * for WRBUFFER|WR -> WR to avoid a new WR sync write from
2062		 * going before a prior buffered writeback happens.
2063		 */
2064		int not = want & ~(have & need);
2065		int revoking = implemented & ~have;
2066		dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
2067		     inode, ceph_cap_string(have), ceph_cap_string(not),
2068		     ceph_cap_string(revoking));
2069		if ((revoking & not) == 0) {
2070			*got = need | (have & want);
2071			__take_cap_refs(ci, *got);
2072			ret = 1;
2073		}
2074	} else {
2075		dout("get_cap_refs %p have %s needed %s\n", inode,
2076		     ceph_cap_string(have), ceph_cap_string(need));
2077	}
2078out:
2079	spin_unlock(&ci->i_ceph_lock);
2080	dout("get_cap_refs %p ret %d got %s\n", inode,
2081	     ret, ceph_cap_string(*got));
2082	return ret;
2083}
2084
2085/*
2086 * Check the offset we are writing up to against our current
2087 * max_size.  If necessary, tell the MDS we want to write to
2088 * a larger offset.
2089 */
2090static void check_max_size(struct inode *inode, loff_t endoff)
2091{
2092	struct ceph_inode_info *ci = ceph_inode(inode);
2093	int check = 0;
2094
2095	/* do we need to explicitly request a larger max_size? */
2096	spin_lock(&ci->i_ceph_lock);
2097	if ((endoff >= ci->i_max_size ||
2098	     endoff > (inode->i_size << 1)) &&
2099	    endoff > ci->i_wanted_max_size) {
2100		dout("write %p at large endoff %llu, req max_size\n",
2101		     inode, endoff);
2102		ci->i_wanted_max_size = endoff;
 
 
 
 
 
 
2103		check = 1;
2104	}
2105	spin_unlock(&ci->i_ceph_lock);
2106	if (check)
2107		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2108}
2109
2110/*
2111 * Wait for caps, and take cap references.  If we can't get a WR cap
2112 * due to a small max_size, make sure we check_max_size (and possibly
2113 * ask the mds) so we don't get hung up indefinitely.
2114 */
2115int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got,
2116		  loff_t endoff)
2117{
2118	int check_max, ret, err;
2119
2120retry:
2121	if (endoff > 0)
2122		check_max_size(&ci->vfs_inode, endoff);
2123	check_max = 0;
2124	err = 0;
2125	ret = wait_event_interruptible(ci->i_cap_wq,
2126				       try_get_cap_refs(ci, need, want,
2127							got, endoff,
2128							&check_max, &err));
2129	if (err)
2130		ret = err;
2131	if (check_max)
2132		goto retry;
2133	return ret;
2134}
2135
2136/*
2137 * Take cap refs.  Caller must already know we hold at least one ref
2138 * on the caps in question or we don't know this is safe.
2139 */
2140void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
2141{
2142	spin_lock(&ci->i_ceph_lock);
2143	__take_cap_refs(ci, caps);
2144	spin_unlock(&ci->i_ceph_lock);
2145}
2146
2147/*
2148 * Release cap refs.
2149 *
2150 * If we released the last ref on any given cap, call ceph_check_caps
2151 * to release (or schedule a release).
2152 *
2153 * If we are releasing a WR cap (from a sync write), finalize any affected
2154 * cap_snap, and wake up any waiters.
2155 */
2156void ceph_put_cap_refs(struct ceph_inode_info *ci, int had)
2157{
2158	struct inode *inode = &ci->vfs_inode;
2159	int last = 0, put = 0, flushsnaps = 0, wake = 0;
2160	struct ceph_cap_snap *capsnap;
2161
2162	spin_lock(&ci->i_ceph_lock);
2163	if (had & CEPH_CAP_PIN)
2164		--ci->i_pin_ref;
2165	if (had & CEPH_CAP_FILE_RD)
2166		if (--ci->i_rd_ref == 0)
2167			last++;
2168	if (had & CEPH_CAP_FILE_CACHE)
2169		if (--ci->i_rdcache_ref == 0)
2170			last++;
2171	if (had & CEPH_CAP_FILE_BUFFER) {
2172		if (--ci->i_wb_ref == 0) {
2173			last++;
2174			put++;
2175		}
2176		dout("put_cap_refs %p wb %d -> %d (?)\n",
2177		     inode, ci->i_wb_ref+1, ci->i_wb_ref);
2178	}
2179	if (had & CEPH_CAP_FILE_WR)
2180		if (--ci->i_wr_ref == 0) {
2181			last++;
2182			if (!list_empty(&ci->i_cap_snaps)) {
2183				capsnap = list_first_entry(&ci->i_cap_snaps,
2184						     struct ceph_cap_snap,
2185						     ci_item);
2186				if (capsnap->writing) {
2187					capsnap->writing = 0;
2188					flushsnaps =
2189						__ceph_finish_cap_snap(ci,
2190								       capsnap);
2191					wake = 1;
2192				}
2193			}
2194		}
2195	spin_unlock(&ci->i_ceph_lock);
2196
2197	dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
2198	     last ? " last" : "", put ? " put" : "");
2199
2200	if (last && !flushsnaps)
2201		ceph_check_caps(ci, 0, NULL);
2202	else if (flushsnaps)
2203		ceph_flush_snaps(ci);
2204	if (wake)
2205		wake_up_all(&ci->i_cap_wq);
2206	if (put)
2207		iput(inode);
2208}
2209
2210/*
2211 * Release @nr WRBUFFER refs on dirty pages for the given @snapc snap
2212 * context.  Adjust per-snap dirty page accounting as appropriate.
2213 * Once all dirty data for a cap_snap is flushed, flush snapped file
2214 * metadata back to the MDS.  If we dropped the last ref, call
2215 * ceph_check_caps.
2216 */
2217void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
2218				struct ceph_snap_context *snapc)
2219{
2220	struct inode *inode = &ci->vfs_inode;
2221	int last = 0;
2222	int complete_capsnap = 0;
2223	int drop_capsnap = 0;
2224	int found = 0;
2225	struct ceph_cap_snap *capsnap = NULL;
2226
2227	spin_lock(&ci->i_ceph_lock);
2228	ci->i_wrbuffer_ref -= nr;
2229	last = !ci->i_wrbuffer_ref;
2230
2231	if (ci->i_head_snapc == snapc) {
2232		ci->i_wrbuffer_ref_head -= nr;
2233		if (ci->i_wrbuffer_ref_head == 0 &&
2234		    ci->i_dirty_caps == 0 && ci->i_flushing_caps == 0) {
2235			BUG_ON(!ci->i_head_snapc);
2236			ceph_put_snap_context(ci->i_head_snapc);
2237			ci->i_head_snapc = NULL;
2238		}
2239		dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n",
2240		     inode,
2241		     ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr,
2242		     ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
2243		     last ? " LAST" : "");
2244	} else {
2245		list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2246			if (capsnap->context == snapc) {
2247				found = 1;
2248				break;
2249			}
2250		}
2251		BUG_ON(!found);
2252		capsnap->dirty_pages -= nr;
2253		if (capsnap->dirty_pages == 0) {
2254			complete_capsnap = 1;
2255			if (capsnap->dirty == 0)
2256				/* cap writeback completed before we created
2257				 * the cap_snap; no FLUSHSNAP is needed */
2258				drop_capsnap = 1;
2259		}
2260		dout("put_wrbuffer_cap_refs on %p cap_snap %p "
2261		     " snap %lld %d/%d -> %d/%d %s%s%s\n",
2262		     inode, capsnap, capsnap->context->seq,
2263		     ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr,
2264		     ci->i_wrbuffer_ref, capsnap->dirty_pages,
2265		     last ? " (wrbuffer last)" : "",
2266		     complete_capsnap ? " (complete capsnap)" : "",
2267		     drop_capsnap ? " (drop capsnap)" : "");
2268		if (drop_capsnap) {
2269			ceph_put_snap_context(capsnap->context);
2270			list_del(&capsnap->ci_item);
2271			list_del(&capsnap->flushing_item);
2272			ceph_put_cap_snap(capsnap);
2273		}
2274	}
2275
2276	spin_unlock(&ci->i_ceph_lock);
2277
2278	if (last) {
2279		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
2280		iput(inode);
2281	} else if (complete_capsnap) {
2282		ceph_flush_snaps(ci);
2283		wake_up_all(&ci->i_cap_wq);
2284	}
2285	if (drop_capsnap)
2286		iput(inode);
2287}
2288
2289/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2290 * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
2291 * actually be a revocation if it specifies a smaller cap set.)
2292 *
2293 * caller holds s_mutex and i_ceph_lock, we drop both.
2294 *
2295 * return value:
2296 *  0 - ok
2297 *  1 - check_caps on auth cap only (writeback)
2298 *  2 - check_caps (ack revoke)
2299 */
2300static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
2301			     struct ceph_mds_session *session,
2302			     struct ceph_cap *cap,
2303			     struct ceph_buffer *xattr_buf)
2304		__releases(ci->i_ceph_lock)
2305{
2306	struct ceph_inode_info *ci = ceph_inode(inode);
2307	int mds = session->s_mds;
2308	int seq = le32_to_cpu(grant->seq);
2309	int newcaps = le32_to_cpu(grant->caps);
2310	int issued, implemented, used, wanted, dirty;
2311	u64 size = le64_to_cpu(grant->size);
2312	u64 max_size = le64_to_cpu(grant->max_size);
2313	struct timespec mtime, atime, ctime;
2314	int check_caps = 0;
2315	int wake = 0;
2316	int writeback = 0;
2317	int revoked_rdcache = 0;
2318	int queue_invalidate = 0;
 
 
2319
2320	dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
2321	     inode, cap, mds, seq, ceph_cap_string(newcaps));
2322	dout(" size %llu max_size %llu, i_size %llu\n", size, max_size,
2323		inode->i_size);
2324
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2325	/*
2326	 * If CACHE is being revoked, and we have no dirty buffers,
2327	 * try to invalidate (once).  (If there are dirty buffers, we
2328	 * will invalidate _after_ writeback.)
2329	 */
2330	if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
2331	    (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
2332	    !ci->i_wrbuffer_ref) {
2333		if (try_nonblocking_invalidate(inode) == 0) {
2334			revoked_rdcache = 1;
2335		} else {
2336			/* there were locked pages.. invalidate later
2337			   in a separate thread. */
2338			if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
2339				queue_invalidate = 1;
2340				ci->i_rdcache_revoking = ci->i_rdcache_gen;
2341			}
2342		}
 
 
2343	}
2344
2345	/* side effects now are allowed */
2346
2347	issued = __ceph_caps_issued(ci, &implemented);
2348	issued |= implemented | __ceph_caps_dirty(ci);
2349
2350	cap->cap_gen = session->s_cap_gen;
 
2351
2352	__check_cap_issue(ci, cap, newcaps);
2353
2354	if ((issued & CEPH_CAP_AUTH_EXCL) == 0) {
2355		inode->i_mode = le32_to_cpu(grant->mode);
2356		inode->i_uid = le32_to_cpu(grant->uid);
2357		inode->i_gid = le32_to_cpu(grant->gid);
2358		dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
2359		     inode->i_uid, inode->i_gid);
 
2360	}
2361
2362	if ((issued & CEPH_CAP_LINK_EXCL) == 0)
2363		set_nlink(inode, le32_to_cpu(grant->nlink));
 
 
 
 
2364
2365	if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
2366		int len = le32_to_cpu(grant->xattr_len);
2367		u64 version = le64_to_cpu(grant->xattr_version);
2368
2369		if (version > ci->i_xattrs.version) {
2370			dout(" got new xattrs v%llu on %p len %d\n",
2371			     version, inode, len);
2372			if (ci->i_xattrs.blob)
2373				ceph_buffer_put(ci->i_xattrs.blob);
2374			ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
2375			ci->i_xattrs.version = version;
 
2376		}
2377	}
2378
 
 
 
 
 
2379	/* size/ctime/mtime/atime? */
2380	ceph_fill_file_size(inode, issued,
2381			    le32_to_cpu(grant->truncate_seq),
2382			    le64_to_cpu(grant->truncate_size), size);
2383	ceph_decode_timespec(&mtime, &grant->mtime);
2384	ceph_decode_timespec(&atime, &grant->atime);
2385	ceph_decode_timespec(&ctime, &grant->ctime);
2386	ceph_fill_file_time(inode, issued,
2387			    le32_to_cpu(grant->time_warp_seq), &ctime, &mtime,
2388			    &atime);
2389
 
 
 
 
2390	/* max size increase? */
2391	if (max_size != ci->i_max_size) {
2392		dout("max_size %lld -> %llu\n", ci->i_max_size, max_size);
2393		ci->i_max_size = max_size;
2394		if (max_size >= ci->i_wanted_max_size) {
2395			ci->i_wanted_max_size = 0;  /* reset */
2396			ci->i_requested_max_size = 0;
2397		}
2398		wake = 1;
2399	}
2400
2401	/* check cap bits */
2402	wanted = __ceph_caps_wanted(ci);
2403	used = __ceph_caps_used(ci);
2404	dirty = __ceph_caps_dirty(ci);
2405	dout(" my wanted = %s, used = %s, dirty %s\n",
2406	     ceph_cap_string(wanted),
2407	     ceph_cap_string(used),
2408	     ceph_cap_string(dirty));
2409	if (wanted != le32_to_cpu(grant->wanted)) {
2410		dout("mds wanted %s -> %s\n",
2411		     ceph_cap_string(le32_to_cpu(grant->wanted)),
2412		     ceph_cap_string(wanted));
2413		grant->wanted = cpu_to_le32(wanted);
 
 
2414	}
2415
2416	cap->seq = seq;
2417
2418	/* file layout may have changed */
2419	ci->i_layout = grant->layout;
2420
2421	/* revocation, grant, or no-op? */
2422	if (cap->issued & ~newcaps) {
2423		int revoking = cap->issued & ~newcaps;
2424
2425		dout("revocation: %s -> %s (revoking %s)\n",
2426		     ceph_cap_string(cap->issued),
2427		     ceph_cap_string(newcaps),
2428		     ceph_cap_string(revoking));
2429		if (revoking & used & CEPH_CAP_FILE_BUFFER)
2430			writeback = 1;  /* initiate writeback; will delay ack */
2431		else if (revoking == CEPH_CAP_FILE_CACHE &&
2432			 (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
2433			 queue_invalidate)
2434			; /* do nothing yet, invalidation will be queued */
2435		else if (cap == ci->i_auth_cap)
2436			check_caps = 1; /* check auth cap only */
2437		else
2438			check_caps = 2; /* check all caps */
2439		cap->issued = newcaps;
2440		cap->implemented |= newcaps;
2441	} else if (cap->issued == newcaps) {
2442		dout("caps unchanged: %s -> %s\n",
2443		     ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
2444	} else {
2445		dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
2446		     ceph_cap_string(newcaps));
 
 
 
 
 
2447		cap->issued = newcaps;
2448		cap->implemented |= newcaps; /* add bits only, to
2449					      * avoid stepping on a
2450					      * pending revocation */
2451		wake = 1;
2452	}
2453	BUG_ON(cap->issued & ~cap->implemented);
2454
2455	spin_unlock(&ci->i_ceph_lock);
 
2456	if (writeback)
2457		/*
2458		 * queue inode for writeback: we can't actually call
2459		 * filemap_write_and_wait, etc. from message handler
2460		 * context.
2461		 */
2462		ceph_queue_writeback(inode);
2463	if (queue_invalidate)
2464		ceph_queue_invalidate(inode);
 
 
 
 
2465	if (wake)
2466		wake_up_all(&ci->i_cap_wq);
2467
2468	if (check_caps == 1)
2469		ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
2470				session);
2471	else if (check_caps == 2)
2472		ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
2473	else
2474		mutex_unlock(&session->s_mutex);
2475}
2476
2477/*
2478 * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
2479 * MDS has been safely committed.
2480 */
2481static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
2482				 struct ceph_mds_caps *m,
2483				 struct ceph_mds_session *session,
2484				 struct ceph_cap *cap)
2485	__releases(ci->i_ceph_lock)
2486{
2487	struct ceph_inode_info *ci = ceph_inode(inode);
2488	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
2489	unsigned seq = le32_to_cpu(m->seq);
2490	int dirty = le32_to_cpu(m->dirty);
2491	int cleaned = 0;
2492	int drop = 0;
2493	int i;
2494
2495	for (i = 0; i < CEPH_CAP_BITS; i++)
2496		if ((dirty & (1 << i)) &&
2497		    flush_tid == ci->i_cap_flush_tid[i])
2498			cleaned |= 1 << i;
2499
2500	dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s,"
2501	     " flushing %s -> %s\n",
2502	     inode, session->s_mds, seq, ceph_cap_string(dirty),
2503	     ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
2504	     ceph_cap_string(ci->i_flushing_caps & ~cleaned));
2505
2506	if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
2507		goto out;
2508
2509	ci->i_flushing_caps &= ~cleaned;
2510
2511	spin_lock(&mdsc->cap_dirty_lock);
2512	if (ci->i_flushing_caps == 0) {
2513		list_del_init(&ci->i_flushing_item);
2514		if (!list_empty(&session->s_cap_flushing))
2515			dout(" mds%d still flushing cap on %p\n",
2516			     session->s_mds,
2517			     &list_entry(session->s_cap_flushing.next,
2518					 struct ceph_inode_info,
2519					 i_flushing_item)->vfs_inode);
2520		mdsc->num_cap_flushing--;
2521		wake_up_all(&mdsc->cap_flushing_wq);
2522		dout(" inode %p now !flushing\n", inode);
2523
2524		if (ci->i_dirty_caps == 0) {
2525			dout(" inode %p now clean\n", inode);
2526			BUG_ON(!list_empty(&ci->i_dirty_item));
2527			drop = 1;
2528			if (ci->i_wrbuffer_ref_head == 0) {
2529				BUG_ON(!ci->i_head_snapc);
2530				ceph_put_snap_context(ci->i_head_snapc);
2531				ci->i_head_snapc = NULL;
2532			}
2533		} else {
2534			BUG_ON(list_empty(&ci->i_dirty_item));
2535		}
2536	}
2537	spin_unlock(&mdsc->cap_dirty_lock);
2538	wake_up_all(&ci->i_cap_wq);
2539
2540out:
2541	spin_unlock(&ci->i_ceph_lock);
2542	if (drop)
2543		iput(inode);
2544}
2545
2546/*
2547 * Handle FLUSHSNAP_ACK.  MDS has flushed snap data to disk and we can
2548 * throw away our cap_snap.
2549 *
2550 * Caller hold s_mutex.
2551 */
2552static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
2553				     struct ceph_mds_caps *m,
2554				     struct ceph_mds_session *session)
2555{
2556	struct ceph_inode_info *ci = ceph_inode(inode);
2557	u64 follows = le64_to_cpu(m->snap_follows);
2558	struct ceph_cap_snap *capsnap;
2559	int drop = 0;
2560
2561	dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n",
2562	     inode, ci, session->s_mds, follows);
2563
2564	spin_lock(&ci->i_ceph_lock);
2565	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
2566		if (capsnap->follows == follows) {
2567			if (capsnap->flush_tid != flush_tid) {
2568				dout(" cap_snap %p follows %lld tid %lld !="
2569				     " %lld\n", capsnap, follows,
2570				     flush_tid, capsnap->flush_tid);
2571				break;
2572			}
2573			WARN_ON(capsnap->dirty_pages || capsnap->writing);
2574			dout(" removing %p cap_snap %p follows %lld\n",
2575			     inode, capsnap, follows);
2576			ceph_put_snap_context(capsnap->context);
2577			list_del(&capsnap->ci_item);
2578			list_del(&capsnap->flushing_item);
2579			ceph_put_cap_snap(capsnap);
2580			drop = 1;
2581			break;
2582		} else {
2583			dout(" skipping cap_snap %p follows %lld\n",
2584			     capsnap, capsnap->follows);
2585		}
2586	}
2587	spin_unlock(&ci->i_ceph_lock);
2588	if (drop)
2589		iput(inode);
2590}
2591
2592/*
2593 * Handle TRUNC from MDS, indicating file truncation.
2594 *
2595 * caller hold s_mutex.
2596 */
2597static void handle_cap_trunc(struct inode *inode,
2598			     struct ceph_mds_caps *trunc,
2599			     struct ceph_mds_session *session)
2600	__releases(ci->i_ceph_lock)
2601{
2602	struct ceph_inode_info *ci = ceph_inode(inode);
2603	int mds = session->s_mds;
2604	int seq = le32_to_cpu(trunc->seq);
2605	u32 truncate_seq = le32_to_cpu(trunc->truncate_seq);
2606	u64 truncate_size = le64_to_cpu(trunc->truncate_size);
2607	u64 size = le64_to_cpu(trunc->size);
2608	int implemented = 0;
2609	int dirty = __ceph_caps_dirty(ci);
2610	int issued = __ceph_caps_issued(ceph_inode(inode), &implemented);
2611	int queue_trunc = 0;
2612
2613	issued |= implemented | dirty;
2614
2615	dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n",
2616	     inode, mds, seq, truncate_size, truncate_seq);
2617	queue_trunc = ceph_fill_file_size(inode, issued,
2618					  truncate_seq, truncate_size, size);
2619	spin_unlock(&ci->i_ceph_lock);
2620
2621	if (queue_trunc)
2622		ceph_queue_vmtruncate(inode);
 
 
2623}
2624
2625/*
2626 * Handle EXPORT from MDS.  Cap is being migrated _from_ this mds to a
2627 * different one.  If we are the most recent migration we've seen (as
2628 * indicated by mseq), make note of the migrating cap bits for the
2629 * duration (until we see the corresponding IMPORT).
2630 *
2631 * caller holds s_mutex
2632 */
2633static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
2634			      struct ceph_mds_session *session,
2635			      int *open_target_sessions)
2636{
2637	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
 
 
2638	struct ceph_inode_info *ci = ceph_inode(inode);
 
 
 
 
2639	int mds = session->s_mds;
2640	unsigned mseq = le32_to_cpu(ex->migrate_seq);
2641	struct ceph_cap *cap = NULL, *t;
2642	struct rb_node *p;
2643	int remember = 1;
2644
2645	dout("handle_cap_export inode %p ci %p mds%d mseq %d\n",
2646	     inode, ci, mds, mseq);
 
 
 
 
 
 
 
2647
 
 
 
2648	spin_lock(&ci->i_ceph_lock);
 
 
 
 
 
 
 
 
2649
2650	/* make sure we haven't seen a higher mseq */
2651	for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
2652		t = rb_entry(p, struct ceph_cap, ci_node);
2653		if (ceph_seq_cmp(t->mseq, mseq) > 0) {
2654			dout(" higher mseq on cap from mds%d\n",
2655			     t->session->s_mds);
2656			remember = 0;
2657		}
2658		if (t->session->s_mds == mds)
2659			cap = t;
2660	}
2661
2662	if (cap) {
2663		if (remember) {
2664			/* make note */
2665			ci->i_cap_exporting_mds = mds;
2666			ci->i_cap_exporting_mseq = mseq;
2667			ci->i_cap_exporting_issued = cap->issued;
2668
2669			/*
2670			 * make sure we have open sessions with all possible
2671			 * export targets, so that we get the matching IMPORT
2672			 */
2673			*open_target_sessions = 1;
2674
2675			/*
2676			 * we can't flush dirty caps that we've seen the
2677			 * EXPORT but no IMPORT for
2678			 */
2679			spin_lock(&mdsc->cap_dirty_lock);
2680			if (!list_empty(&ci->i_dirty_item)) {
2681				dout(" moving %p to cap_dirty_migrating\n",
2682				     inode);
2683				list_move(&ci->i_dirty_item,
2684					  &mdsc->cap_dirty_migrating);
 
 
 
 
 
 
 
 
 
2685			}
2686			spin_unlock(&mdsc->cap_dirty_lock);
2687		}
2688		__ceph_remove_cap(cap);
 
 
 
 
 
 
 
 
 
 
2689	}
2690	/* else, we already released it */
2691
2692	spin_unlock(&ci->i_ceph_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2693}
2694
2695/*
2696 * Handle cap IMPORT.  If there are temp bits from an older EXPORT,
2697 * clean them up.
2698 *
2699 * caller holds s_mutex.
2700 */
2701static void handle_cap_import(struct ceph_mds_client *mdsc,
2702			      struct inode *inode, struct ceph_mds_caps *im,
 
2703			      struct ceph_mds_session *session,
2704			      void *snaptrace, int snaptrace_len)
2705{
2706	struct ceph_inode_info *ci = ceph_inode(inode);
 
2707	int mds = session->s_mds;
2708	unsigned issued = le32_to_cpu(im->caps);
2709	unsigned wanted = le32_to_cpu(im->wanted);
2710	unsigned seq = le32_to_cpu(im->seq);
2711	unsigned mseq = le32_to_cpu(im->migrate_seq);
2712	u64 realmino = le64_to_cpu(im->realm);
2713	u64 cap_id = le64_to_cpu(im->cap_id);
 
 
2714
2715	if (ci->i_cap_exporting_mds >= 0 &&
2716	    ceph_seq_cmp(ci->i_cap_exporting_mseq, mseq) < 0) {
2717		dout("handle_cap_import inode %p ci %p mds%d mseq %d"
2718		     " - cleared exporting from mds%d\n",
2719		     inode, ci, mds, mseq,
2720		     ci->i_cap_exporting_mds);
2721		ci->i_cap_exporting_issued = 0;
2722		ci->i_cap_exporting_mseq = 0;
2723		ci->i_cap_exporting_mds = -1;
 
2724
2725		spin_lock(&mdsc->cap_dirty_lock);
2726		if (!list_empty(&ci->i_dirty_item)) {
2727			dout(" moving %p back to cap_dirty\n", inode);
2728			list_move(&ci->i_dirty_item, &mdsc->cap_dirty);
 
 
 
 
 
 
 
 
 
 
2729		}
2730		spin_unlock(&mdsc->cap_dirty_lock);
2731	} else {
2732		dout("handle_cap_import inode %p ci %p mds%d mseq %d\n",
2733		     inode, ci, mds, mseq);
2734	}
2735
 
 
 
 
 
2736	down_write(&mdsc->snap_rwsem);
2737	ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len,
2738			       false);
2739	downgrade_write(&mdsc->snap_rwsem);
2740	ceph_add_cap(inode, session, cap_id, -1,
2741		     issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH,
2742		     NULL /* no caps context */);
2743	kick_flushing_inode_caps(mdsc, session, inode);
2744	up_read(&mdsc->snap_rwsem);
2745
2746	/* make sure we re-request max_size, if necessary */
2747	spin_lock(&ci->i_ceph_lock);
2748	ci->i_requested_max_size = 0;
2749	spin_unlock(&ci->i_ceph_lock);
2750}
2751
2752/*
2753 * Handle a caps message from the MDS.
2754 *
2755 * Identify the appropriate session, inode, and call the right handler
2756 * based on the cap op.
2757 */
2758void ceph_handle_caps(struct ceph_mds_session *session,
2759		      struct ceph_msg *msg)
2760{
2761	struct ceph_mds_client *mdsc = session->s_mdsc;
2762	struct super_block *sb = mdsc->fsc->sb;
2763	struct inode *inode;
2764	struct ceph_inode_info *ci;
2765	struct ceph_cap *cap;
2766	struct ceph_mds_caps *h;
 
2767	int mds = session->s_mds;
2768	int op;
2769	u32 seq, mseq;
2770	struct ceph_vino vino;
2771	u64 cap_id;
2772	u64 size, max_size;
2773	u64 tid;
2774	void *snaptrace;
2775	size_t snaptrace_len;
2776	void *flock;
 
2777	u32 flock_len;
2778	int open_target_sessions = 0;
2779
2780	dout("handle_caps from mds%d\n", mds);
2781
2782	/* decode */
 
2783	tid = le64_to_cpu(msg->hdr.tid);
2784	if (msg->front.iov_len < sizeof(*h))
2785		goto bad;
2786	h = msg->front.iov_base;
2787	op = le32_to_cpu(h->op);
2788	vino.ino = le64_to_cpu(h->ino);
2789	vino.snap = CEPH_NOSNAP;
2790	cap_id = le64_to_cpu(h->cap_id);
2791	seq = le32_to_cpu(h->seq);
2792	mseq = le32_to_cpu(h->migrate_seq);
2793	size = le64_to_cpu(h->size);
2794	max_size = le64_to_cpu(h->max_size);
2795
2796	snaptrace = h + 1;
2797	snaptrace_len = le32_to_cpu(h->snap_trace_len);
2798
2799	if (le16_to_cpu(msg->hdr.version) >= 2) {
2800		void *p, *end;
2801
2802		p = snaptrace + snaptrace_len;
2803		end = msg->front.iov_base + msg->front.iov_len;
2804		ceph_decode_32_safe(&p, end, flock_len, bad);
 
 
2805		flock = p;
2806	} else {
2807		flock = NULL;
2808		flock_len = 0;
2809	}
2810
 
 
 
 
 
 
 
 
 
 
 
 
2811	mutex_lock(&session->s_mutex);
2812	session->s_seq++;
2813	dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
2814	     (unsigned)seq);
2815
 
 
 
2816	/* lookup ino */
2817	inode = ceph_find_inode(sb, vino);
2818	ci = ceph_inode(inode);
2819	dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
2820	     vino.snap, inode);
2821	if (!inode) {
2822		dout(" i don't have ino %llx\n", vino.ino);
2823
2824		if (op == CEPH_CAP_OP_IMPORT)
 
2825			__queue_cap_release(session, vino.ino, cap_id,
2826					    mseq, seq);
 
 
2827		goto flush_cap_releases;
2828	}
2829
2830	/* these will work even if we don't have a cap yet */
2831	switch (op) {
2832	case CEPH_CAP_OP_FLUSHSNAP_ACK:
2833		handle_cap_flushsnap_ack(inode, tid, h, session);
2834		goto done;
2835
2836	case CEPH_CAP_OP_EXPORT:
2837		handle_cap_export(inode, h, session, &open_target_sessions);
2838		goto done;
2839
2840	case CEPH_CAP_OP_IMPORT:
2841		handle_cap_import(mdsc, inode, h, session,
2842				  snaptrace, snaptrace_len);
2843		ceph_check_caps(ceph_inode(inode), 0, session);
2844		goto done_unlocked;
2845	}
2846
2847	/* the rest require a cap */
2848	spin_lock(&ci->i_ceph_lock);
2849	cap = __get_cap_for_mds(ceph_inode(inode), mds);
2850	if (!cap) {
2851		dout(" no cap on %p ino %llx.%llx from mds%d\n",
2852		     inode, ceph_ino(inode), ceph_snap(inode), mds);
2853		spin_unlock(&ci->i_ceph_lock);
2854		goto flush_cap_releases;
2855	}
2856
2857	/* note that each of these drops i_ceph_lock for us */
2858	switch (op) {
2859	case CEPH_CAP_OP_REVOKE:
2860	case CEPH_CAP_OP_GRANT:
 
2861		handle_cap_grant(inode, h, session, cap, msg->middle);
2862		goto done_unlocked;
2863
2864	case CEPH_CAP_OP_FLUSH_ACK:
2865		handle_cap_flush_ack(inode, tid, h, session, cap);
2866		break;
2867
2868	case CEPH_CAP_OP_TRUNC:
2869		handle_cap_trunc(inode, h, session);
2870		break;
2871
2872	default:
2873		spin_unlock(&ci->i_ceph_lock);
2874		pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
2875		       ceph_cap_op_name(op));
2876	}
2877
2878	goto done;
2879
2880flush_cap_releases:
2881	/*
2882	 * send any full release message to try to move things
2883	 * along for the mds (who clearly thinks we still have this
2884	 * cap).
2885	 */
2886	ceph_add_cap_releases(mdsc, session);
2887	ceph_send_cap_releases(mdsc, session);
2888
2889done:
2890	mutex_unlock(&session->s_mutex);
2891done_unlocked:
2892	if (inode)
2893		iput(inode);
2894	if (open_target_sessions)
2895		ceph_mdsc_open_export_target_sessions(mdsc, session);
2896	return;
2897
2898bad:
2899	pr_err("ceph_handle_caps: corrupt message\n");
2900	ceph_msg_dump(msg);
2901	return;
2902}
2903
2904/*
2905 * Delayed work handler to process end of delayed cap release LRU list.
2906 */
2907void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
2908{
2909	struct ceph_inode_info *ci;
2910	int flags = CHECK_CAPS_NODELAY;
2911
2912	dout("check_delayed_caps\n");
2913	while (1) {
2914		spin_lock(&mdsc->cap_delay_lock);
2915		if (list_empty(&mdsc->cap_delay_list))
2916			break;
2917		ci = list_first_entry(&mdsc->cap_delay_list,
2918				      struct ceph_inode_info,
2919				      i_cap_delay_list);
2920		if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 &&
2921		    time_before(jiffies, ci->i_hold_caps_max))
2922			break;
2923		list_del_init(&ci->i_cap_delay_list);
2924		spin_unlock(&mdsc->cap_delay_lock);
2925		dout("check_delayed_caps on %p\n", &ci->vfs_inode);
2926		ceph_check_caps(ci, flags, NULL);
2927	}
2928	spin_unlock(&mdsc->cap_delay_lock);
2929}
2930
2931/*
2932 * Flush all dirty caps to the mds
2933 */
2934void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
2935{
2936	struct ceph_inode_info *ci;
2937	struct inode *inode;
2938
2939	dout("flush_dirty_caps\n");
2940	spin_lock(&mdsc->cap_dirty_lock);
2941	while (!list_empty(&mdsc->cap_dirty)) {
2942		ci = list_first_entry(&mdsc->cap_dirty, struct ceph_inode_info,
2943				      i_dirty_item);
2944		inode = &ci->vfs_inode;
2945		ihold(inode);
2946		dout("flush_dirty_caps %p\n", inode);
2947		spin_unlock(&mdsc->cap_dirty_lock);
2948		ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH, NULL);
2949		iput(inode);
2950		spin_lock(&mdsc->cap_dirty_lock);
2951	}
2952	spin_unlock(&mdsc->cap_dirty_lock);
2953	dout("flush_dirty_caps done\n");
2954}
2955
2956/*
2957 * Drop open file reference.  If we were the last open file,
2958 * we may need to release capabilities to the MDS (or schedule
2959 * their delayed release).
2960 */
2961void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
2962{
2963	struct inode *inode = &ci->vfs_inode;
2964	int last = 0;
2965
2966	spin_lock(&ci->i_ceph_lock);
2967	dout("put_fmode %p fmode %d %d -> %d\n", inode, fmode,
2968	     ci->i_nr_by_mode[fmode], ci->i_nr_by_mode[fmode]-1);
2969	BUG_ON(ci->i_nr_by_mode[fmode] == 0);
2970	if (--ci->i_nr_by_mode[fmode] == 0)
2971		last++;
2972	spin_unlock(&ci->i_ceph_lock);
2973
2974	if (last && ci->i_vino.snap == CEPH_NOSNAP)
2975		ceph_check_caps(ci, 0, NULL);
2976}
2977
2978/*
2979 * Helpers for embedding cap and dentry lease releases into mds
2980 * requests.
2981 *
2982 * @force is used by dentry_release (below) to force inclusion of a
2983 * record for the directory inode, even when there aren't any caps to
2984 * drop.
2985 */
2986int ceph_encode_inode_release(void **p, struct inode *inode,
2987			      int mds, int drop, int unless, int force)
2988{
2989	struct ceph_inode_info *ci = ceph_inode(inode);
2990	struct ceph_cap *cap;
2991	struct ceph_mds_request_release *rel = *p;
2992	int used, dirty;
2993	int ret = 0;
2994
2995	spin_lock(&ci->i_ceph_lock);
2996	used = __ceph_caps_used(ci);
2997	dirty = __ceph_caps_dirty(ci);
2998
2999	dout("encode_inode_release %p mds%d used|dirty %s drop %s unless %s\n",
3000	     inode, mds, ceph_cap_string(used|dirty), ceph_cap_string(drop),
3001	     ceph_cap_string(unless));
3002
3003	/* only drop unused, clean caps */
3004	drop &= ~(used | dirty);
3005
3006	cap = __get_cap_for_mds(ci, mds);
3007	if (cap && __cap_is_valid(cap)) {
3008		if (force ||
3009		    ((cap->issued & drop) &&
3010		     (cap->issued & unless) == 0)) {
3011			if ((cap->issued & drop) &&
3012			    (cap->issued & unless) == 0) {
3013				dout("encode_inode_release %p cap %p %s -> "
3014				     "%s\n", inode, cap,
 
 
 
3015				     ceph_cap_string(cap->issued),
3016				     ceph_cap_string(cap->issued & ~drop));
 
 
 
3017				cap->issued &= ~drop;
3018				cap->implemented &= ~drop;
3019				if (ci->i_ceph_flags & CEPH_I_NODELAY) {
3020					int wanted = __ceph_caps_wanted(ci);
3021					dout("  wanted %s -> %s (act %s)\n",
3022					     ceph_cap_string(cap->mds_wanted),
3023					     ceph_cap_string(cap->mds_wanted &
3024							     ~wanted),
3025					     ceph_cap_string(wanted));
3026					cap->mds_wanted &= wanted;
3027				}
3028			} else {
3029				dout("encode_inode_release %p cap %p %s"
3030				     " (force)\n", inode, cap,
3031				     ceph_cap_string(cap->issued));
3032			}
3033
3034			rel->ino = cpu_to_le64(ceph_ino(inode));
3035			rel->cap_id = cpu_to_le64(cap->cap_id);
3036			rel->seq = cpu_to_le32(cap->seq);
3037			rel->issue_seq = cpu_to_le32(cap->issue_seq),
3038			rel->mseq = cpu_to_le32(cap->mseq);
3039			rel->caps = cpu_to_le32(cap->issued);
3040			rel->wanted = cpu_to_le32(cap->mds_wanted);
3041			rel->dname_len = 0;
3042			rel->dname_seq = 0;
3043			*p += sizeof(*rel);
3044			ret = 1;
3045		} else {
3046			dout("encode_inode_release %p cap %p %s\n",
3047			     inode, cap, ceph_cap_string(cap->issued));
3048		}
3049	}
3050	spin_unlock(&ci->i_ceph_lock);
3051	return ret;
3052}
3053
3054int ceph_encode_dentry_release(void **p, struct dentry *dentry,
3055			       int mds, int drop, int unless)
3056{
3057	struct inode *dir = dentry->d_parent->d_inode;
3058	struct ceph_mds_request_release *rel = *p;
3059	struct ceph_dentry_info *di = ceph_dentry(dentry);
3060	int force = 0;
3061	int ret;
3062
3063	/*
3064	 * force an record for the directory caps if we have a dentry lease.
3065	 * this is racy (can't take i_ceph_lock and d_lock together), but it
3066	 * doesn't have to be perfect; the mds will revoke anything we don't
3067	 * release.
3068	 */
3069	spin_lock(&dentry->d_lock);
3070	if (di->lease_session && di->lease_session->s_mds == mds)
3071		force = 1;
3072	spin_unlock(&dentry->d_lock);
3073
3074	ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force);
3075
3076	spin_lock(&dentry->d_lock);
3077	if (ret && di->lease_session && di->lease_session->s_mds == mds) {
3078		dout("encode_dentry_release %p mds%d seq %d\n",
3079		     dentry, mds, (int)di->lease_seq);
3080		rel->dname_len = cpu_to_le32(dentry->d_name.len);
3081		memcpy(*p, dentry->d_name.name, dentry->d_name.len);
3082		*p += dentry->d_name.len;
3083		rel->dname_seq = cpu_to_le32(di->lease_seq);
3084		__ceph_mdsc_drop_dentry_lease(dentry);
3085	}
3086	spin_unlock(&dentry->d_lock);
3087	return ret;
3088}