/fs/ceph/caps.c
C | 3087 lines | 2272 code | 326 blank | 489 comment | 450 complexity | 420bae9a1f20f122fa6e49b116857865 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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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_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->vfs_inode.i_lock);
336 cap = __get_cap_for_mds(ci, mds);
337 spin_unlock(&ci->vfs_inode.i_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 int mds;
365 spin_lock(&inode->i_lock);
366 mds = __ceph_get_cap_mds(ceph_inode(inode));
367 spin_unlock(&inode->i_lock);
368 return mds;
369}
370
371/*
372 * Called under i_lock.
373 */
374static void __insert_cap_node(struct ceph_inode_info *ci,
375 struct ceph_cap *new)
376{
377 struct rb_node **p = &ci->i_caps.rb_node;
378 struct rb_node *parent = NULL;
379 struct ceph_cap *cap = NULL;
380
381 while (*p) {
382 parent = *p;
383 cap = rb_entry(parent, struct ceph_cap, ci_node);
384 if (new->mds < cap->mds)
385 p = &(*p)->rb_left;
386 else if (new->mds > cap->mds)
387 p = &(*p)->rb_right;
388 else
389 BUG();
390 }
391
392 rb_link_node(&new->ci_node, parent, p);
393 rb_insert_color(&new->ci_node, &ci->i_caps);
394}
395
396/*
397 * (re)set cap hold timeouts, which control the delayed release
398 * of unused caps back to the MDS. Should be called on cap use.
399 */
400static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
401 struct ceph_inode_info *ci)
402{
403 struct ceph_mount_options *ma = mdsc->fsc->mount_options;
404
405 ci->i_hold_caps_min = round_jiffies(jiffies +
406 ma->caps_wanted_delay_min * HZ);
407 ci->i_hold_caps_max = round_jiffies(jiffies +
408 ma->caps_wanted_delay_max * HZ);
409 dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
410 ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
411}
412
413/*
414 * (Re)queue cap at the end of the delayed cap release list.
415 *
416 * If I_FLUSH is set, leave the inode at the front of the list.
417 *
418 * Caller holds i_lock
419 * -> we take mdsc->cap_delay_lock
420 */
421static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
422 struct ceph_inode_info *ci)
423{
424 __cap_set_timeouts(mdsc, ci);
425 dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
426 ci->i_ceph_flags, ci->i_hold_caps_max);
427 if (!mdsc->stopping) {
428 spin_lock(&mdsc->cap_delay_lock);
429 if (!list_empty(&ci->i_cap_delay_list)) {
430 if (ci->i_ceph_flags & CEPH_I_FLUSH)
431 goto no_change;
432 list_del_init(&ci->i_cap_delay_list);
433 }
434 list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
435no_change:
436 spin_unlock(&mdsc->cap_delay_lock);
437 }
438}
439
440/*
441 * Queue an inode for immediate writeback. Mark inode with I_FLUSH,
442 * indicating we should send a cap message to flush dirty metadata
443 * asap, and move to the front of the delayed cap list.
444 */
445static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
446 struct ceph_inode_info *ci)
447{
448 dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
449 spin_lock(&mdsc->cap_delay_lock);
450 ci->i_ceph_flags |= CEPH_I_FLUSH;
451 if (!list_empty(&ci->i_cap_delay_list))
452 list_del_init(&ci->i_cap_delay_list);
453 list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
454 spin_unlock(&mdsc->cap_delay_lock);
455}
456
457/*
458 * Cancel delayed work on cap.
459 *
460 * Caller must hold i_lock.
461 */
462static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
463 struct ceph_inode_info *ci)
464{
465 dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
466 if (list_empty(&ci->i_cap_delay_list))
467 return;
468 spin_lock(&mdsc->cap_delay_lock);
469 list_del_init(&ci->i_cap_delay_list);
470 spin_unlock(&mdsc->cap_delay_lock);
471}
472
473/*
474 * Common issue checks for add_cap, handle_cap_grant.
475 */
476static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
477 unsigned issued)
478{
479 unsigned had = __ceph_caps_issued(ci, NULL);
480
481 /*
482 * Each time we receive FILE_CACHE anew, we increment
483 * i_rdcache_gen.
484 */
485 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
486 (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
487 ci->i_rdcache_gen++;
488
489 /*
490 * if we are newly issued FILE_SHARED, clear I_COMPLETE; we
491 * don't know what happened to this directory while we didn't
492 * have the cap.
493 */
494 if ((issued & CEPH_CAP_FILE_SHARED) &&
495 (had & CEPH_CAP_FILE_SHARED) == 0) {
496 ci->i_shared_gen++;
497 if (S_ISDIR(ci->vfs_inode.i_mode)) {
498 dout(" marking %p NOT complete\n", &ci->vfs_inode);
499 ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
500 }
501 }
502}
503
504/*
505 * Add a capability under the given MDS session.
506 *
507 * Caller should hold session snap_rwsem (read) and s_mutex.
508 *
509 * @fmode is the open file mode, if we are opening a file, otherwise
510 * it is < 0. (This is so we can atomically add the cap and add an
511 * open file reference to it.)
512 */
513int ceph_add_cap(struct inode *inode,
514 struct ceph_mds_session *session, u64 cap_id,
515 int fmode, unsigned issued, unsigned wanted,
516 unsigned seq, unsigned mseq, u64 realmino, int flags,
517 struct ceph_cap_reservation *caps_reservation)
518{
519 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
520 struct ceph_inode_info *ci = ceph_inode(inode);
521 struct ceph_cap *new_cap = NULL;
522 struct ceph_cap *cap;
523 int mds = session->s_mds;
524 int actual_wanted;
525
526 dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
527 session->s_mds, cap_id, ceph_cap_string(issued), seq);
528
529 /*
530 * If we are opening the file, include file mode wanted bits
531 * in wanted.
532 */
533 if (fmode >= 0)
534 wanted |= ceph_caps_for_mode(fmode);
535
536retry:
537 spin_lock(&inode->i_lock);
538 cap = __get_cap_for_mds(ci, mds);
539 if (!cap) {
540 if (new_cap) {
541 cap = new_cap;
542 new_cap = NULL;
543 } else {
544 spin_unlock(&inode->i_lock);
545 new_cap = get_cap(mdsc, caps_reservation);
546 if (new_cap == NULL)
547 return -ENOMEM;
548 goto retry;
549 }
550
551 cap->issued = 0;
552 cap->implemented = 0;
553 cap->mds = mds;
554 cap->mds_wanted = 0;
555
556 cap->ci = ci;
557 __insert_cap_node(ci, cap);
558
559 /* clear out old exporting info? (i.e. on cap import) */
560 if (ci->i_cap_exporting_mds == mds) {
561 ci->i_cap_exporting_issued = 0;
562 ci->i_cap_exporting_mseq = 0;
563 ci->i_cap_exporting_mds = -1;
564 }
565
566 /* add to session cap list */
567 cap->session = session;
568 spin_lock(&session->s_cap_lock);
569 list_add_tail(&cap->session_caps, &session->s_caps);
570 session->s_nr_caps++;
571 spin_unlock(&session->s_cap_lock);
572 } else if (new_cap)
573 ceph_put_cap(mdsc, new_cap);
574
575 if (!ci->i_snap_realm) {
576 /*
577 * add this inode to the appropriate snap realm
578 */
579 struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
580 realmino);
581 if (realm) {
582 ceph_get_snap_realm(mdsc, realm);
583 spin_lock(&realm->inodes_with_caps_lock);
584 ci->i_snap_realm = realm;
585 list_add(&ci->i_snap_realm_item,
586 &realm->inodes_with_caps);
587 spin_unlock(&realm->inodes_with_caps_lock);
588 } else {
589 pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
590 realmino);
591 WARN_ON(!realm);
592 }
593 }
594
595 __check_cap_issue(ci, cap, issued);
596
597 /*
598 * If we are issued caps we don't want, or the mds' wanted
599 * value appears to be off, queue a check so we'll release
600 * later and/or update the mds wanted value.
601 */
602 actual_wanted = __ceph_caps_wanted(ci);
603 if ((wanted & ~actual_wanted) ||
604 (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
605 dout(" issued %s, mds wanted %s, actual %s, queueing\n",
606 ceph_cap_string(issued), ceph_cap_string(wanted),
607 ceph_cap_string(actual_wanted));
608 __cap_delay_requeue(mdsc, ci);
609 }
610
611 if (flags & CEPH_CAP_FLAG_AUTH)
612 ci->i_auth_cap = cap;
613 else if (ci->i_auth_cap == cap)
614 ci->i_auth_cap = NULL;
615
616 dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
617 inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
618 ceph_cap_string(issued|cap->issued), seq, mds);
619 cap->cap_id = cap_id;
620 cap->issued = issued;
621 cap->implemented |= issued;
622 cap->mds_wanted |= wanted;
623 cap->seq = seq;
624 cap->issue_seq = seq;
625 cap->mseq = mseq;
626 cap->cap_gen = session->s_cap_gen;
627
628 if (fmode >= 0)
629 __ceph_get_fmode(ci, fmode);
630 spin_unlock(&inode->i_lock);
631 wake_up_all(&ci->i_cap_wq);
632 return 0;
633}
634
635/*
636 * Return true if cap has not timed out and belongs to the current
637 * generation of the MDS session (i.e. has not gone 'stale' due to
638 * us losing touch with the mds).
639 */
640static int __cap_is_valid(struct ceph_cap *cap)
641{
642 unsigned long ttl;
643 u32 gen;
644
645 spin_lock(&cap->session->s_cap_lock);
646 gen = cap->session->s_cap_gen;
647 ttl = cap->session->s_cap_ttl;
648 spin_unlock(&cap->session->s_cap_lock);
649
650 if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
651 dout("__cap_is_valid %p cap %p issued %s "
652 "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
653 cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
654 return 0;
655 }
656
657 return 1;
658}
659
660/*
661 * Return set of valid cap bits issued to us. Note that caps time
662 * out, and may be invalidated in bulk if the client session times out
663 * and session->s_cap_gen is bumped.
664 */
665int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
666{
667 int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
668 struct ceph_cap *cap;
669 struct rb_node *p;
670
671 if (implemented)
672 *implemented = 0;
673 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
674 cap = rb_entry(p, struct ceph_cap, ci_node);
675 if (!__cap_is_valid(cap))
676 continue;
677 dout("__ceph_caps_issued %p cap %p issued %s\n",
678 &ci->vfs_inode, cap, ceph_cap_string(cap->issued));
679 have |= cap->issued;
680 if (implemented)
681 *implemented |= cap->implemented;
682 }
683 return have;
684}
685
686/*
687 * Get cap bits issued by caps other than @ocap
688 */
689int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
690{
691 int have = ci->i_snap_caps;
692 struct ceph_cap *cap;
693 struct rb_node *p;
694
695 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
696 cap = rb_entry(p, struct ceph_cap, ci_node);
697 if (cap == ocap)
698 continue;
699 if (!__cap_is_valid(cap))
700 continue;
701 have |= cap->issued;
702 }
703 return have;
704}
705
706/*
707 * Move a cap to the end of the LRU (oldest caps at list head, newest
708 * at list tail).
709 */
710static void __touch_cap(struct ceph_cap *cap)
711{
712 struct ceph_mds_session *s = cap->session;
713
714 spin_lock(&s->s_cap_lock);
715 if (s->s_cap_iterator == NULL) {
716 dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
717 s->s_mds);
718 list_move_tail(&cap->session_caps, &s->s_caps);
719 } else {
720 dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
721 &cap->ci->vfs_inode, cap, s->s_mds);
722 }
723 spin_unlock(&s->s_cap_lock);
724}
725
726/*
727 * Check if we hold the given mask. If so, move the cap(s) to the
728 * front of their respective LRUs. (This is the preferred way for
729 * callers to check for caps they want.)
730 */
731int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
732{
733 struct ceph_cap *cap;
734 struct rb_node *p;
735 int have = ci->i_snap_caps;
736
737 if ((have & mask) == mask) {
738 dout("__ceph_caps_issued_mask %p snap issued %s"
739 " (mask %s)\n", &ci->vfs_inode,
740 ceph_cap_string(have),
741 ceph_cap_string(mask));
742 return 1;
743 }
744
745 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
746 cap = rb_entry(p, struct ceph_cap, ci_node);
747 if (!__cap_is_valid(cap))
748 continue;
749 if ((cap->issued & mask) == mask) {
750 dout("__ceph_caps_issued_mask %p cap %p issued %s"
751 " (mask %s)\n", &ci->vfs_inode, cap,
752 ceph_cap_string(cap->issued),
753 ceph_cap_string(mask));
754 if (touch)
755 __touch_cap(cap);
756 return 1;
757 }
758
759 /* does a combination of caps satisfy mask? */
760 have |= cap->issued;
761 if ((have & mask) == mask) {
762 dout("__ceph_caps_issued_mask %p combo issued %s"
763 " (mask %s)\n", &ci->vfs_inode,
764 ceph_cap_string(cap->issued),
765 ceph_cap_string(mask));
766 if (touch) {
767 struct rb_node *q;
768
769 /* touch this + preceding caps */
770 __touch_cap(cap);
771 for (q = rb_first(&ci->i_caps); q != p;
772 q = rb_next(q)) {
773 cap = rb_entry(q, struct ceph_cap,
774 ci_node);
775 if (!__cap_is_valid(cap))
776 continue;
777 __touch_cap(cap);
778 }
779 }
780 return 1;
781 }
782 }
783
784 return 0;
785}
786
787/*
788 * Return true if mask caps are currently being revoked by an MDS.
789 */
790int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
791{
792 struct inode *inode = &ci->vfs_inode;
793 struct ceph_cap *cap;
794 struct rb_node *p;
795 int ret = 0;
796
797 spin_lock(&inode->i_lock);
798 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
799 cap = rb_entry(p, struct ceph_cap, ci_node);
800 if (__cap_is_valid(cap) &&
801 (cap->implemented & ~cap->issued & mask)) {
802 ret = 1;
803 break;
804 }
805 }
806 spin_unlock(&inode->i_lock);
807 dout("ceph_caps_revoking %p %s = %d\n", inode,
808 ceph_cap_string(mask), ret);
809 return ret;
810}
811
812int __ceph_caps_used(struct ceph_inode_info *ci)
813{
814 int used = 0;
815 if (ci->i_pin_ref)
816 used |= CEPH_CAP_PIN;
817 if (ci->i_rd_ref)
818 used |= CEPH_CAP_FILE_RD;
819 if (ci->i_rdcache_ref || ci->vfs_inode.i_data.nrpages)
820 used |= CEPH_CAP_FILE_CACHE;
821 if (ci->i_wr_ref)
822 used |= CEPH_CAP_FILE_WR;
823 if (ci->i_wb_ref || ci->i_wrbuffer_ref)
824 used |= CEPH_CAP_FILE_BUFFER;
825 return used;
826}
827
828/*
829 * wanted, by virtue of open file modes
830 */
831int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
832{
833 int want = 0;
834 int mode;
835 for (mode = 0; mode < CEPH_FILE_MODE_NUM; mode++)
836 if (ci->i_nr_by_mode[mode])
837 want |= ceph_caps_for_mode(mode);
838 return want;
839}
840
841/*
842 * Return caps we have registered with the MDS(s) as 'wanted'.
843 */
844int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
845{
846 struct ceph_cap *cap;
847 struct rb_node *p;
848 int mds_wanted = 0;
849
850 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
851 cap = rb_entry(p, struct ceph_cap, ci_node);
852 if (!__cap_is_valid(cap))
853 continue;
854 mds_wanted |= cap->mds_wanted;
855 }
856 return mds_wanted;
857}
858
859/*
860 * called under i_lock
861 */
862static int __ceph_is_any_caps(struct ceph_inode_info *ci)
863{
864 return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_mds >= 0;
865}
866
867/*
868 * Remove a cap. Take steps to deal with a racing iterate_session_caps.
869 *
870 * caller should hold i_lock.
871 * caller will not hold session s_mutex if called from destroy_inode.
872 */
873void __ceph_remove_cap(struct ceph_cap *cap)
874{
875 struct ceph_mds_session *session = cap->session;
876 struct ceph_inode_info *ci = cap->ci;
877 struct ceph_mds_client *mdsc =
878 ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
879 int removed = 0;
880
881 dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
882
883 /* remove from session list */
884 spin_lock(&session->s_cap_lock);
885 if (session->s_cap_iterator == cap) {
886 /* not yet, we are iterating over this very cap */
887 dout("__ceph_remove_cap delaying %p removal from session %p\n",
888 cap, cap->session);
889 } else {
890 list_del_init(&cap->session_caps);
891 session->s_nr_caps--;
892 cap->session = NULL;
893 removed = 1;
894 }
895 /* protect backpointer with s_cap_lock: see iterate_session_caps */
896 cap->ci = NULL;
897 spin_unlock(&session->s_cap_lock);
898
899 /* remove from inode list */
900 rb_erase(&cap->ci_node, &ci->i_caps);
901 if (ci->i_auth_cap == cap)
902 ci->i_auth_cap = NULL;
903
904 if (removed)
905 ceph_put_cap(mdsc, cap);
906
907 if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
908 struct ceph_snap_realm *realm = ci->i_snap_realm;
909 spin_lock(&realm->inodes_with_caps_lock);
910 list_del_init(&ci->i_snap_realm_item);
911 ci->i_snap_realm_counter++;
912 ci->i_snap_realm = NULL;
913 spin_unlock(&realm->inodes_with_caps_lock);
914 ceph_put_snap_realm(mdsc, realm);
915 }
916 if (!__ceph_is_any_real_caps(ci))
917 __cap_delay_cancel(mdsc, ci);
918}
919
920/*
921 * Build and send a cap message to the given MDS.
922 *
923 * Caller should be holding s_mutex.
924 */
925static int send_cap_msg(struct ceph_mds_session *session,
926 u64 ino, u64 cid, int op,
927 int caps, int wanted, int dirty,
928 u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq,
929 u64 size, u64 max_size,
930 struct timespec *mtime, struct timespec *atime,
931 u64 time_warp_seq,
932 uid_t uid, gid_t gid, mode_t mode,
933 u64 xattr_version,
934 struct ceph_buffer *xattrs_buf,
935 u64 follows)
936{
937 struct ceph_mds_caps *fc;
938 struct ceph_msg *msg;
939
940 dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
941 " seq %u/%u mseq %u follows %lld size %llu/%llu"
942 " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op),
943 cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
944 ceph_cap_string(dirty),
945 seq, issue_seq, mseq, follows, size, max_size,
946 xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
947
948 msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), GFP_NOFS);
949 if (!msg)
950 return -ENOMEM;
951
952 msg->hdr.tid = cpu_to_le64(flush_tid);
953
954 fc = msg->front.iov_base;
955 memset(fc, 0, sizeof(*fc));
956
957 fc->cap_id = cpu_to_le64(cid);
958 fc->op = cpu_to_le32(op);
959 fc->seq = cpu_to_le32(seq);
960 fc->issue_seq = cpu_to_le32(issue_seq);
961 fc->migrate_seq = cpu_to_le32(mseq);
962 fc->caps = cpu_to_le32(caps);
963 fc->wanted = cpu_to_le32(wanted);
964 fc->dirty = cpu_to_le32(dirty);
965 fc->ino = cpu_to_le64(ino);
966 fc->snap_follows = cpu_to_le64(follows);
967
968 fc->size = cpu_to_le64(size);
969 fc->max_size = cpu_to_le64(max_size);
970 if (mtime)
971 ceph_encode_timespec(&fc->mtime, mtime);
972 if (atime)
973 ceph_encode_timespec(&fc->atime, atime);
974 fc->time_warp_seq = cpu_to_le32(time_warp_seq);
975
976 fc->uid = cpu_to_le32(uid);
977 fc->gid = cpu_to_le32(gid);
978 fc->mode = cpu_to_le32(mode);
979
980 fc->xattr_version = cpu_to_le64(xattr_version);
981 if (xattrs_buf) {
982 msg->middle = ceph_buffer_get(xattrs_buf);
983 fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len);
984 msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len);
985 }
986
987 ceph_con_send(&session->s_con, msg);
988 return 0;
989}
990
991static void __queue_cap_release(struct ceph_mds_session *session,
992 u64 ino, u64 cap_id, u32 migrate_seq,
993 u32 issue_seq)
994{
995 struct ceph_msg *msg;
996 struct ceph_mds_cap_release *head;
997 struct ceph_mds_cap_item *item;
998
999 spin_lock(&session->s_cap_lock);
1000 BUG_ON(!session->s_num_cap_releases);
1001 msg = list_first_entry(&session->s_cap_releases,
1002 struct ceph_msg, list_head);
1003
1004 dout(" adding %llx release to mds%d msg %p (%d left)\n",
1005 ino, session->s_mds, msg, session->s_num_cap_releases);
1006
1007 BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
1008 head = msg->front.iov_base;
1009 head->num = cpu_to_le32(le32_to_cpu(head->num) + 1);
1010 item = msg->front.iov_base + msg->front.iov_len;
1011 item->ino = cpu_to_le64(ino);
1012 item->cap_id = cpu_to_le64(cap_id);
1013 item->migrate_seq = cpu_to_le32(migrate_seq);
1014 item->seq = cpu_to_le32(issue_seq);
1015
1016 session->s_num_cap_releases--;
1017
1018 msg->front.iov_len += sizeof(*item);
1019 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1020 dout(" release msg %p full\n", msg);
1021 list_move_tail(&msg->list_head, &session->s_cap_releases_done);
1022 } else {
1023 dout(" release msg %p at %d/%d (%d)\n", msg,
1024 (int)le32_to_cpu(head->num),
1025 (int)CEPH_CAPS_PER_RELEASE,
1026 (int)msg->front.iov_len);
1027 }
1028 spin_unlock(&session->s_cap_lock);
1029}
1030
1031/*
1032 * Queue cap releases when an inode is dropped from our cache. Since
1033 * inode is about to be destroyed, there is no need for i_lock.
1034 */
1035void ceph_queue_caps_release(struct inode *inode)
1036{
1037 struct ceph_inode_info *ci = ceph_inode(inode);
1038 struct rb_node *p;
1039
1040 p = rb_first(&ci->i_caps);
1041 while (p) {
1042 struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
1043 struct ceph_mds_session *session = cap->session;
1044
1045 __queue_cap_release(session, ceph_ino(inode), cap->cap_id,
1046 cap->mseq, cap->issue_seq);
1047 p = rb_next(p);
1048 __ceph_remove_cap(cap);
1049 }
1050}
1051
1052/*
1053 * Send a cap msg on the given inode. Update our caps state, then
1054 * drop i_lock and send the message.
1055 *
1056 * Make note of max_size reported/requested from mds, revoked caps
1057 * that have now been implemented.
1058 *
1059 * Make half-hearted attempt ot to invalidate page cache if we are
1060 * dropping RDCACHE. Note that this will leave behind locked pages
1061 * that we'll then need to deal with elsewhere.
1062 *
1063 * Return non-zero if delayed release, or we experienced an error
1064 * such that the caller should requeue + retry later.
1065 *
1066 * called with i_lock, then drops it.
1067 * caller should hold snap_rwsem (read), s_mutex.
1068 */
1069static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
1070 int op, int used, int want, int retain, int flushing,
1071 unsigned *pflush_tid)
1072 __releases(cap->ci->vfs_inode->i_lock)
1073{
1074 struct ceph_inode_info *ci = cap->ci;
1075 struct inode *inode = &ci->vfs_inode;
1076 u64 cap_id = cap->cap_id;
1077 int held, revoking, dropping, keep;
1078 u64 seq, issue_seq, mseq, time_warp_seq, follows;
1079 u64 size, max_size;
1080 struct timespec mtime, atime;
1081 int wake = 0;
1082 mode_t mode;
1083 uid_t uid;
1084 gid_t gid;
1085 struct ceph_mds_session *session;
1086 u64 xattr_version = 0;
1087 struct ceph_buffer *xattr_blob = NULL;
1088 int delayed = 0;
1089 u64 flush_tid = 0;
1090 int i;
1091 int ret;
1092
1093 held = cap->issued | cap->implemented;
1094 revoking = cap->implemented & ~cap->issued;
1095 retain &= ~revoking;
1096 dropping = cap->issued & ~retain;
1097
1098 dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
1099 inode, cap, cap->session,
1100 ceph_cap_string(held), ceph_cap_string(held & retain),
1101 ceph_cap_string(revoking));
1102 BUG_ON((retain & CEPH_CAP_PIN) == 0);
1103
1104 session = cap->session;
1105
1106 /* don't release wanted unless we've waited a bit. */
1107 if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1108 time_before(jiffies, ci->i_hold_caps_min)) {
1109 dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
1110 ceph_cap_string(cap->issued),
1111 ceph_cap_string(cap->issued & retain),
1112 ceph_cap_string(cap->mds_wanted),
1113 ceph_cap_string(want));
1114 want |= cap->mds_wanted;
1115 retain |= cap->issued;
1116 delayed = 1;
1117 }
1118 ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
1119
1120 cap->issued &= retain; /* drop bits we don't want */
1121 if (cap->implemented & ~cap->issued) {
1122 /*
1123 * Wake up any waiters on wanted -> needed transition.
1124 * This is due to the weird transition from buffered
1125 * to sync IO... we need to flush dirty pages _before_
1126 * allowing sync writes to avoid reordering.
1127 */
1128 wake = 1;
1129 }
1130 cap->implemented &= cap->issued | used;
1131 cap->mds_wanted = want;
1132
1133 if (flushing) {
1134 /*
1135 * assign a tid for flush operations so we can avoid
1136 * flush1 -> dirty1 -> flush2 -> flushack1 -> mark
1137 * clean type races. track latest tid for every bit
1138 * so we can handle flush AxFw, flush Fw, and have the
1139 * first ack clean Ax.
1140 */
1141 flush_tid = ++ci->i_cap_flush_last_tid;
1142 if (pflush_tid)
1143 *pflush_tid = flush_tid;
1144 dout(" cap_flush_tid %d\n", (int)flush_tid);
1145 for (i = 0; i < CEPH_CAP_BITS; i++)
1146 if (flushing & (1 << i))
1147 ci->i_cap_flush_tid[i] = flush_tid;
1148
1149 follows = ci->i_head_snapc->seq;
1150 } else {
1151 follows = 0;
1152 }
1153
1154 keep = cap->implemented;
1155 seq = cap->seq;
1156 issue_seq = cap->issue_seq;
1157 mseq = cap->mseq;
1158 size = inode->i_size;
1159 ci->i_reported_size = size;
1160 max_size = ci->i_wanted_max_size;
1161 ci->i_requested_max_size = max_size;
1162 mtime = inode->i_mtime;
1163 atime = inode->i_atime;
1164 time_warp_seq = ci->i_time_warp_seq;
1165 uid = inode->i_uid;
1166 gid = inode->i_gid;
1167 mode = inode->i_mode;
1168
1169 if (flushing & CEPH_CAP_XATTR_EXCL) {
1170 __ceph_build_xattrs_blob(ci);
1171 xattr_blob = ci->i_xattrs.blob;
1172 xattr_version = ci->i_xattrs.version;
1173 }
1174
1175 spin_unlock(&inode->i_lock);
1176
1177 ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
1178 op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
1179 size, max_size, &mtime, &atime, time_warp_seq,
1180 uid, gid, mode, xattr_version, xattr_blob,
1181 follows);
1182 if (ret < 0) {
1183 dout("error sending cap msg, must requeue %p\n", inode);
1184 delayed = 1;
1185 }
1186
1187 if (wake)
1188 wake_up_all(&ci->i_cap_wq);
1189
1190 return delayed;
1191}
1192
1193/*
1194 * When a snapshot is taken, clients accumulate dirty metadata on
1195 * inodes with capabilities in ceph_cap_snaps to describe the file
1196 * state at the time the snapshot was taken. This must be flushed
1197 * asynchronously back to the MDS once sync writes complete and dirty
1198 * data is written out.
1199 *
1200 * Unless @again is true, skip cap_snaps that were already sent to
1201 * the MDS (i.e., during this session).
1202 *
1203 * Called under i_lock. Takes s_mutex as needed.
1204 */
1205void __ceph_flush_snaps(struct ceph_inode_info *ci,
1206 struct ceph_mds_session **psession,
1207 int again)
1208 __releases(ci->vfs_inode->i_lock)
1209 __acquires(ci->vfs_inode->i_lock)
1210{
1211 struct inode *inode = &ci->vfs_inode;
1212 int mds;
1213 struct ceph_cap_snap *capsnap;
1214 u32 mseq;
1215 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1216 struct ceph_mds_session *session = NULL; /* if session != NULL, we hold
1217 session->s_mutex */
1218 u64 next_follows = 0; /* keep track of how far we've gotten through the
1219 i_cap_snaps list, and skip these entries next time
1220 around to avoid an infinite loop */
1221
1222 if (psession)
1223 session = *psession;
1224
1225 dout("__flush_snaps %p\n", inode);
1226retry:
1227 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
1228 /* avoid an infiniute loop after retry */
1229 if (capsnap->follows < next_follows)
1230 continue;
1231 /*
1232 * we need to wait for sync writes to complete and for dirty
1233 * pages to be written out.
1234 */
1235 if (capsnap->dirty_pages || capsnap->writing)
1236 break;
1237
1238 /*
1239 * if cap writeback already occurred, we should have dropped
1240 * the capsnap in ceph_put_wrbuffer_cap_refs.
1241 */
1242 BUG_ON(capsnap->dirty == 0);
1243
1244 /* pick mds, take s_mutex */
1245 if (ci->i_auth_cap == NULL) {
1246 dout("no auth cap (migrating?), doing nothing\n");
1247 goto out;
1248 }
1249
1250 /* only flush each capsnap once */
1251 if (!again && !list_empty(&capsnap->flushing_item)) {
1252 dout("already flushed %p, skipping\n", capsnap);
1253 continue;
1254 }
1255
1256 mds = ci->i_auth_cap->session->s_mds;
1257 mseq = ci->i_auth_cap->mseq;
1258
1259 if (session && session->s_mds != mds) {
1260 dout("oops, wrong session %p mutex\n", session);
1261 mutex_unlock(&session->s_mutex);
1262 ceph_put_mds_session(session);
1263 session = NULL;
1264 }
1265 if (!session) {
1266 spin_unlock(&inode->i_lock);
1267 mutex_lock(&mdsc->mutex);
1268 session = __ceph_lookup_mds_session(mdsc, mds);
1269 mutex_unlock(&mdsc->mutex);
1270 if (session) {
1271 dout("inverting session/ino locks on %p\n",
1272 session);
1273 mutex_lock(&session->s_mutex);
1274 }
1275 /*
1276 * if session == NULL, we raced against a cap
1277 * deletion or migration. retry, and we'll
1278 * get a better @mds value next time.
1279 */
1280 spin_lock(&inode->i_lock);
1281 goto retry;
1282 }
1283
1284 capsnap->flush_tid = ++ci->i_cap_flush_last_tid;
1285 atomic_inc(&capsnap->nref);
1286 if (!list_empty(&capsnap->flushing_item))
1287 list_del_init(&capsnap->flushing_item);
1288 list_add_tail(&capsnap->flushing_item,
1289 &session->s_cap_snaps_flushing);
1290 spin_unlock(&inode->i_lock);
1291
1292 dout("flush_snaps %p cap_snap %p follows %lld tid %llu\n",
1293 inode, capsnap, capsnap->follows, capsnap->flush_tid);
1294 send_cap_msg(session, ceph_vino(inode).ino, 0,
1295 CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
1296 capsnap->dirty, 0, capsnap->flush_tid, 0, mseq,
1297 capsnap->size, 0,
1298 &capsnap->mtime, &capsnap->atime,
1299 capsnap->time_warp_seq,
1300 capsnap->uid, capsnap->gid, capsnap->mode,
1301 capsnap->xattr_version, capsnap->xattr_blob,
1302 capsnap->follows);
1303
1304 next_follows = capsnap->follows + 1;
1305 ceph_put_cap_snap(capsnap);
1306
1307 spin_lock(&inode->i_lock);
1308 goto retry;
1309 }
1310
1311 /* we flushed them all; remove this inode from the queue */
1312 spin_lock(&mdsc->snap_flush_lock);
1313 list_del_init(&ci->i_snap_flush_item);
1314 spin_unlock(&mdsc->snap_flush_lock);
1315
1316out:
1317 if (psession)
1318 *psession = session;
1319 else if (session) {
1320 mutex_unlock(&session->s_mutex);
1321 ceph_put_mds_session(session);
1322 }
1323}
1324
1325static void ceph_flush_snaps(struct ceph_inode_info *ci)
1326{
1327 struct inode *inode = &ci->vfs_inode;
1328
1329 spin_lock(&inode->i_lock);
1330 __ceph_flush_snaps(ci, NULL, 0);
1331 spin_unlock(&inode->i_lock);
1332}
1333
1334/*
1335 * Mark caps dirty. If inode is newly dirty, return the dirty flags.
1336 * Caller is then responsible for calling __mark_inode_dirty with the
1337 * returned flags value.
1338 */
1339int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
1340{
1341 struct ceph_mds_client *mdsc =
1342 ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc;
1343 struct inode *inode = &ci->vfs_inode;
1344 int was = ci->i_dirty_caps;
1345 int dirty = 0;
1346
1347 dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
1348 ceph_cap_string(mask), ceph_cap_string(was),
1349 ceph_cap_string(was | mask));
1350 ci->i_dirty_caps |= mask;
1351 if (was == 0) {
1352 if (!ci->i_head_snapc)
1353 ci->i_head_snapc = ceph_get_snap_context(
1354 ci->i_snap_realm->cached_context);
1355 dout(" inode %p now dirty snapc %p\n", &ci->vfs_inode,
1356 ci->i_head_snapc);
1357 BUG_ON(!list_empty(&ci->i_dirty_item));
1358 spin_lock(&mdsc->cap_dirty_lock);
1359 list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
1360 spin_unlock(&mdsc->cap_dirty_lock);
1361 if (ci->i_flushing_caps == 0) {
1362 ihold(inode);
1363 dirty |= I_DIRTY_SYNC;
1364 }
1365 }
1366 BUG_ON(list_empty(&ci->i_dirty_item));
1367 if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
1368 (mask & CEPH_CAP_FILE_BUFFER))
1369 dirty |= I_DIRTY_DATASYNC;
1370 __cap_delay_requeue(mdsc, ci);
1371 return dirty;
1372}
1373
1374/*
1375 * Add dirty inode to the flushing list. Assigned a seq number so we
1376 * can wait for caps to flush without starving.
1377 *
1378 * Called under i_lock.
1379 */
1380static int __mark_caps_flushing(struct inode *inode,
1381 struct ceph_mds_session *session)
1382{
1383 struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1384 struct ceph_inode_info *ci = ceph_inode(inode);
1385 int flushing;
1386
1387 BUG_ON(ci->i_dirty_caps == 0);
1388 BUG_ON(list_empty(&ci->i_dirty_item));
1389
1390 flushing = ci->i_dirty_caps;
1391 dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
1392 ceph_cap_string(flushing),
1393 ceph_cap_string(ci->i_flushing_caps),
1394 ceph_cap_string(ci->i_flushing_caps | flushing));
1395 ci->i_flushing_caps |= flushing;
1396 ci->i_dirty_caps = 0;
1397 dout(" inode %p now !dirty\n", inode);
1398
1399 spin_lock(&mdsc->cap_dirty_lock);
1400 list_del_init(&ci->i_dirty_item);
1401
1402 ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
1403 if (list_empty(&ci->i_flushing_item)) {
1404 list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1405 mdsc->num_cap_flushing++;
1406 dout(" inode %p now flushing seq %lld\n", inode,
1407 ci->i_cap_flush_seq);
1408 } else {
1409 list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
1410 dout(" inode %p now flushing (more) seq %lld\n", inode,
1411 ci->i_cap_flush_seq);
1412 }
1413 spin_unlock(&mdsc->cap_dirty_lock);
1414
1415 return flushing;
1416}
1417
1418/*
1419 * try to invalidate mapping pages without blocking.
1420 */
1421static int try_nonblocking_invalidate(struct inode *inode)
1422{
1423 struct ceph_inode_info *ci = ceph_inode(inode);
1424 u32 invalidating_gen = ci->i_rdcache_gen;
1425
1426 spin_unlock(&inode->i_lock);
1427 invalidate_mapping_pages(&inode->i_data, 0, -1);
1428 spin_lock(&inode->i_lock);
1429
1430 if (inode->i_data.nrpages == 0 &&
1431 invalidating_gen == ci->i_rdcache_gen) {
1432 /* success. */
1433 dout("try_nonblocking_invalidate %p success\n", inode);
1434 /* save any racing async invalidate some trouble */
1435 ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
1436 return 0;
1437 }
1438 dout("try_nonblocking_invalidate %p failed\n", inode);
1439 return -1;
1440}
1441
1442/*
1443 * Swiss army knife function to examine currently used and wanted
1444 * versus held caps. Release, flush, ack revoked caps to mds as
1445 * appropriate.
1446 *
1447 * CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
1448 * cap release further.
1449 * CHECK_CAPS_AUTHONLY - we should only check the auth cap
1450 * CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
1451 * further delay.
1452 */
1453void ceph_check_caps(struct ceph_inode_info *ci, int flags,
1454 struct ceph_mds_session *session)
1455{
1456 struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1457 struct ceph_mds_client *mdsc = fsc->mdsc;
1458 struct inode *inode = &ci->vfs_inode;
1459 struct ceph_cap *cap;
1460 int file_wanted, used;
1461 int took_snap_rwsem = 0; /* true if mdsc->snap_rwsem held */
1462 int issued, implemented, want, retain, revoking, flushing = 0;
1463 int mds = -1; /* keep track of how far we've gone through i_caps list
1464 to avoid an infinite loop on retry */
1465 struct rb_node *p;
1466 int tried_invalidate = 0;
1467 int delayed = 0, sent = 0, force_requeue = 0, num;
1468 int queue_invalidate = 0;
1469 int is_delayed = flags & CHECK_CAPS_NODELAY;
1470
1471 /* if we are unmounting, flush any unused caps immediately. */
1472 if (mdsc->stopping)
1473 is_delayed = 1;
1474
1475 spin_lock(&inode->i_lock);
1476
1477 if (ci->i_ceph_flags & CEPH_I_FLUSH)
1478 flags |= CHECK_CAPS_FLUSH;
1479
1480 /* flush snaps first time around only */
1481 if (!list_empty(&ci->i_cap_snaps))
1482 __ceph_flush_snaps(ci, &session, 0);
1483 goto retry_locked;
1484retry:
1485 spin_lock(&inode->i_lock);
1486retry_locked:
1487 file_wanted = __ceph_caps_file_wanted(ci);
1488 used = __ceph_caps_used(ci);
1489 want = file_wanted | used;
1490 issued = __ceph_caps_issued(ci, &implemented);
1491 revoking = implemented & ~issued;
1492
1493 retain = want | CEPH_CAP_PIN;
1494 if (!mdsc->stopping && inode->i_nlink > 0) {
1495 if (want) {
1496 retain |= CEPH_CAP_ANY; /* be greedy */
1497 } else {
1498 retain |= CEPH_CAP_ANY_SHARED;
1499 /*
1500 * keep RD only if we didn't have the file open RW,
1501 * because then the mds would revoke it anyway to
1502 * journal max_size=0.
1503 */
1504 if (ci->i_max_size == 0)
1505 retain |= CEPH_CAP_ANY_RD;
1506 }
1507 }
1508
1509 dout("check_caps %p file_want %s used %s dirty %s flushing %s"
1510 " issued %s revoking %s retain %s %s%s%s\n", inode,
1511 ceph_cap_string(file_wanted),
1512 ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
1513 ceph_cap_string(ci->i_flushing_caps),
1514 ceph_cap_string(issued), ceph_cap_string(revoking),
1515 ceph_cap_string(retain),
1516 (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
1517 (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
1518 (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
1519
1520 /*
1521 * If we no longer need to hold onto old our caps, and we may
1522 * have cached pages, but don't want them, then try to invalidate.
1523 * If we fail, it's because pages are locked.... try again later.
1524 */
1525 if ((!is_delayed || mdsc->stopping) &&
1526 ci->i_wrbuffer_ref == 0 && /* no dirty pages... */
1527 inode->i_data.nrpages && /* have cached pages */
1528 (file_wanted == 0 || /* no open files */
1529 (revoking & (CEPH_CAP_FILE_CACHE|
1530 CEPH_CAP_FILE_LAZYIO))) && /* or revoking cache */
1531 !tried_invalidate) {
1532 dout("check_caps trying to invalidate on %p\n", inode);
1533 if (try_nonblocking_invalidate(inode) < 0) {
1534 if (revoking & (CEPH_CAP_FILE_CACHE|
1535 CEPH_CAP_FILE_LAZYIO)) {
1536 dout("check_caps queuing invalidate\n");
1537 queue_invalidate = 1;
1538 ci->i_rdcache_revoking = ci->i_rdcache_gen;
1539 } else {
1540 dout("check_caps failed to invalidate pages\n");
1541 /* we failed to invalidate pages. check these
1542 caps again later. */
1543 force_requeue = 1;
1544 __cap_set_timeouts(mdsc, ci);
1545 }
1546 }
1547 tried_invalidate = 1;
1548 goto retry_locked;
1549 }
1550
1551 num = 0;
1552 for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
1553 cap = rb_entry(p, struct ceph_cap, ci_node);
1554 num++;
1555
1556 /* avoid looping forever */
1557 if (mds >= cap->mds ||
1558 ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
1559 continue;
1560
1561 /* NOTE: no side-effects allowed, until we take s_mutex */
1562
1563 revoking = cap->implemented & ~cap->issued;
1564 dout(" mds%d cap %p issued %s implemented %s revoking %s\n",
1565 cap->mds, cap, ceph_cap_string(cap->issued),
1566 ceph_cap_string(cap->implemented),
1567 ceph_cap_string(revoking));
1568
1569 if (cap == ci->i_auth_cap &&
1570 (cap->issued & CEPH_CAP_FILE_WR)) {
1571 /* request larger max_size from MDS? */
1572 if (ci->i_wanted_max_size > ci->i_max_size &&
1573 ci->i_wanted_max_size > ci->i_requested_max_size) {
1574 dout("requesting new max_size\n");
1575 goto ack;
1576 }
1577
1578 /* approaching file_max? */
1579 if ((inode->i_size << 1) >= ci->i_max_size &&
1580 (ci->i_reported_size << 1) < ci->i_max_size) {
1581 dout("i_size approaching max_size\n");
1582 goto ack;
1583 }
1584 }
1585 /* flush anything dirty? */
1586 if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) &&
1587 ci->i_dirty_caps) {
1588 dout("flushing dirty caps\n");
1589 goto ack;
1590 }
1591
1592 /* completed revocation? going down and there are no caps? */
1593 if (revoking && (revoking & used) == 0) {
1594 dout("completed revocation of %s\n",
1595 ceph_cap_string(cap->implemented & ~cap->issued));
1596 goto ack;
1597 }
1598
1599 /* want more caps from mds? */
1600 if (want & ~(cap->mds_wanted | cap->issued))
1601 goto ack;
1602
1603 /* things we might delay */
1604 if ((cap->issued & ~retain) == 0 &&
1605 cap->mds_wanted == want)
1606 continue; /* nope, all good */
1607
1608 if (is_delayed)
1609 goto ack;
1610
1611 /* delay? */
1612 if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
1613 time_before(jiffies, ci->i_hold_caps_max)) {
1614 dout(" delaying issued %s -> %s, wanted %s -> %s\n",
1615 ceph_cap_string(cap->issued),
1616 ceph_cap_string(cap->issued & retain),
1617 ceph_cap_string(cap->mds_wanted),
1618 ceph_cap_string(want));
1619 delayed++;
1620 continue;
1621 }
1622
1623ack:
1624 if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1625 dout(" skipping %p I_NOFLUSH set\n", inode);
1626 continue;
1627 }
1628
1629 if (session && session != cap->session) {
1630 dout("oops, wrong session %p mutex\n", session);
1631 mutex_unlock(&session->s_mutex);
1632 session = NULL;
1633 }
1634 if (!session) {
1635 session = cap->session;
1636 if (mutex_trylock(&session->s_mutex) == 0) {
1637 dout("inverting session/ino locks on %p\n",
1638 session);
1639 spin_unlock(&inode->i_lock);
1640 if (took_snap_rwsem) {
1641 up_read(&mdsc->snap_rwsem);
1642 took_snap_rwsem = 0;
1643 }
1644 mutex_lock(&session->s_mutex);
1645 goto retry;
1646 }
1647 }
1648 /* take snap_rwsem after session mutex */
1649 if (!took_snap_rwsem) {
1650 if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
1651 dout("inverting snap/in locks on %p\n",
1652 inode);
1653 spin_unlock(&inode->i_lock);
1654 down_read(&mdsc->snap_rwsem);
1655 took_snap_rwsem = 1;
1656 goto retry;
1657 }
1658 took_snap_rwsem = 1;
1659 }
1660
1661 if (cap == ci->i_auth_cap && ci->i_dirty_caps)
1662 flushing = __mark_caps_flushing(inode, session);
1663 else
1664 flushing = 0;
1665
1666 mds = cap->mds; /* remember mds, so we don't repeat */
1667 sent++;
1668
1669 /* __send_cap drops i_lock */
1670 delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want,
1671 retain, flushing, NULL);
1672 goto retry; /* retake i_lock and restart our cap scan. */
1673 }
1674
1675 /*
1676 * Reschedule delayed caps release if we delayed anything,
1677 * otherwise cancel.
1678 */
1679 if (delayed && is_delayed)
1680 force_requeue = 1; /* __send_cap delayed release; requeue */
1681 if (!delayed && !is_delayed)
1682 __cap_delay_cancel(mdsc, ci);
1683 else if (!is_delayed || force_requeue)
1684 __cap_delay_requeue(mdsc, ci);
1685
1686 spin_unlock(&inode->i_lock);
1687
1688 if (queue_invalidate)
1689 ceph_queue_invalidate(inode);
1690
1691 if (session)
1692 mutex_unlock(&session->s_mutex);
1693 if (took_snap_rwsem)
1694 up_read(&mdsc->snap_rwsem);
1695}
1696
1697/*
1698 * Try to flush dirty caps back to the auth mds.
1699 */
1700static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session,
1701 unsigned *flush_tid)
1702{
1703 struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
1704 struct ceph_inode_info *ci = ceph_inode(inode);
1705 int unlock_session = session ? 0 : 1;
1706 int flushing = 0;
1707
1708retry:
1709 spin_lock(&inode->i_lock);
1710 if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
1711 dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
1712 goto out;
1713 }
1714 if (ci->i_dirty_caps && ci->i_auth_cap) {
1715 struct ceph_cap *cap = ci->i_auth_cap;
1716 int used = __ceph_caps_used(ci);
1717 int want = __ceph_caps_wanted(ci);
1718 int delayed;
1719
1720 if (!session) {
1721 spin_unlock(&inode->i_lock);
1722 session = cap->session;
1723 mutex_lock(&session->s_mutex);
1724 goto retry;
1725 }
1726 BUG_ON(session != cap->session);
1727 if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
1728 goto out;
1729
1730 flushing = __mark_caps_flushing(inode, session);
1731
1732 /* __send_cap drops i_lock */
1733 delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
1734 cap->issued | cap->implemented, flushing,
1735 flush_tid);
1736 if (!delayed)
1737 goto out_unlocked;
1738
1739 spin_lock(&inode->i_lock);
1740 __cap_delay_requeue(mdsc, ci);
1741 }
1742out:
1743 spin_unlock(&inode->i_lock);
1744out_unlocked:
1745 if (session && unlock_session)
1746 mutex_unlock(&session->s_mutex);
1747 return flushing;
1748}
1749
1750/*
1751 * Return true if we've flushed caps through the given flush_tid.
1752 */
1753static int caps_are_flushed(struct inode *inode, unsigned tid)
1754{
1755 struct ceph_inode_info *ci = ceph_inode(inode);
1756 int i, ret = 1;
1757
1758 spin_lock(&inode->i_lock);
1759 for (i = 0; i < CEPH_CAP_BITS; i++)
1760 if ((ci->i_flushing_caps & (1 << i)) &&
1761 ci->i_cap_flush_tid[i] <= tid) {
1762 /* still flushing this bit */
1763 ret = 0;
1764 break;
1765 }
1766 spin_unlock(&inode->i_lock);
1767 return ret;
1768}
1769
1770/*
1771 * Wait on any unsafe replies for the given inode. First wait on the
1772 * newest request, and make that the upper bound. Then, if there are
1773 * more requests, keep waiting on the oldest as long as it is still older
1774 * than the original request.
1775 */
1776static void sync_write_wait(struct inode *inode)
1777{
1778 struct ceph_inode_info *ci = ceph_inode(inode);
1779 struct list_head *head = &ci->i_unsafe_writes;
1780 struct ceph_osd_request *req;
1781 u64 last_tid;
1782
1783 spin_lock(&ci->i_unsafe_lock);
1784 if (list_empty(head))
1785 goto out;
1786
1787 /* set upper bound as _last_ entry in chain */
1788 req = list_entry(head->prev, struct ceph_osd_request,
1789 r_unsafe_item);
1790 last_tid = req->r_tid;
1791
1792 do {
1793 ceph_osdc_get_request(req);
1794 spin_unlock(&ci->i_unsafe_lock);
1795 dout("sync_write_wait on tid %llu (until %llu)\n",
1796 req->r_tid, last_tid);
1797 wait_for_completion(&req->r_safe_completion);
1798 spin_lock(&ci->i_unsafe_lock);
1799 ceph_osdc_put_request(req);
1800
1801 /*
1802 * from here on look at first entry in chain, since we
1803 * only want to wait for anything older than last_tid
1804 */
1805 if (list_empty(head))
1806 break;
1807 req = list_entry(head->next, struct ceph_osd_request,
1808 r_unsafe_item);
1809 } while (req->r_tid < last_tid);
1810out:
1811 spin_unlock(&ci->i_unsafe_lock);
1812}
1813
1814int cep…Large files files are truncated, but you can click here to view the full file