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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/staging/lustre/lustre/llite/statahead.c
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2012, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
38 #include <linux/sched.h>
40 #include <linux/highmem.h>
41 #include <linux/pagemap.h>
43 #define DEBUG_SUBSYSTEM S_LLITE
45 #include "../include/obd_support.h"
46 #include "../include/lustre_lite.h"
47 #include "../include/lustre_dlm.h"
48 #include "llite_internal.h"
50 #define SA_OMITTED_ENTRY_MAX 8ULL
53 /** negative values are for error cases */
54 SA_ENTRY_INIT
= 0, /** init entry */
55 SA_ENTRY_SUCC
= 1, /** stat succeed */
56 SA_ENTRY_INVA
= 2, /** invalid entry */
57 SA_ENTRY_DEST
= 3, /** entry to be destroyed */
61 /* link into sai->sai_entries */
62 struct list_head se_link
;
63 /* link into sai->sai_entries_{received,stated} */
64 struct list_head se_list
;
65 /* link into sai hash table locally */
66 struct list_head se_hash
;
67 /* entry reference count */
69 /* entry index in the sai */
71 /* low layer ldlm lock handle */
75 /* entry size, contains name */
77 /* pointer to async getattr enqueue info */
78 struct md_enqueue_info
*se_minfo
;
79 /* pointer to the async getattr request */
80 struct ptlrpc_request
*se_req
;
81 /* pointer to the target inode */
82 struct inode
*se_inode
;
87 static unsigned int sai_generation
= 0;
88 static DEFINE_SPINLOCK(sai_generation_lock
);
90 static inline int ll_sa_entry_unhashed(struct ll_sa_entry
*entry
)
92 return list_empty(&entry
->se_hash
);
96 * The entry only can be released by the caller, it is necessary to hold lock.
98 static inline int ll_sa_entry_stated(struct ll_sa_entry
*entry
)
101 return (entry
->se_stat
!= SA_ENTRY_INIT
);
104 static inline int ll_sa_entry_hash(int val
)
106 return val
& LL_SA_CACHE_MASK
;
110 * Insert entry to hash SA table.
113 ll_sa_entry_enhash(struct ll_statahead_info
*sai
, struct ll_sa_entry
*entry
)
115 int i
= ll_sa_entry_hash(entry
->se_qstr
.hash
);
117 spin_lock(&sai
->sai_cache_lock
[i
]);
118 list_add_tail(&entry
->se_hash
, &sai
->sai_cache
[i
]);
119 spin_unlock(&sai
->sai_cache_lock
[i
]);
123 * Remove entry from SA table.
126 ll_sa_entry_unhash(struct ll_statahead_info
*sai
, struct ll_sa_entry
*entry
)
128 int i
= ll_sa_entry_hash(entry
->se_qstr
.hash
);
130 spin_lock(&sai
->sai_cache_lock
[i
]);
131 list_del_init(&entry
->se_hash
);
132 spin_unlock(&sai
->sai_cache_lock
[i
]);
135 static inline int agl_should_run(struct ll_statahead_info
*sai
,
138 return (inode
!= NULL
&& S_ISREG(inode
->i_mode
) && sai
->sai_agl_valid
);
141 static inline struct ll_sa_entry
*
142 sa_first_received_entry(struct ll_statahead_info
*sai
)
144 return list_entry(sai
->sai_entries_received
.next
,
145 struct ll_sa_entry
, se_list
);
148 static inline struct ll_inode_info
*
149 agl_first_entry(struct ll_statahead_info
*sai
)
151 return list_entry(sai
->sai_entries_agl
.next
,
152 struct ll_inode_info
, lli_agl_list
);
155 static inline int sa_sent_full(struct ll_statahead_info
*sai
)
157 return atomic_read(&sai
->sai_cache_count
) >= sai
->sai_max
;
160 static inline int sa_received_empty(struct ll_statahead_info
*sai
)
162 return list_empty(&sai
->sai_entries_received
);
165 static inline int agl_list_empty(struct ll_statahead_info
*sai
)
167 return list_empty(&sai
->sai_entries_agl
);
171 * (1) hit ratio less than 80%
173 * (2) consecutive miss more than 8
174 * then means low hit.
176 static inline int sa_low_hit(struct ll_statahead_info
*sai
)
178 return ((sai
->sai_hit
> 7 && sai
->sai_hit
< 4 * sai
->sai_miss
) ||
179 (sai
->sai_consecutive_miss
> 8));
183 * If the given index is behind of statahead window more than
184 * SA_OMITTED_ENTRY_MAX, then it is old.
186 static inline int is_omitted_entry(struct ll_statahead_info
*sai
, __u64 index
)
188 return ((__u64
)sai
->sai_max
+ index
+ SA_OMITTED_ENTRY_MAX
<
193 * Insert it into sai_entries tail when init.
195 static struct ll_sa_entry
*
196 ll_sa_entry_alloc(struct ll_statahead_info
*sai
, __u64 index
,
197 const char *name
, int len
)
199 struct ll_inode_info
*lli
;
200 struct ll_sa_entry
*entry
;
204 entry_size
= sizeof(struct ll_sa_entry
) + (len
& ~3) + 4;
205 entry
= kzalloc(entry_size
, GFP_NOFS
);
206 if (unlikely(!entry
))
207 return ERR_PTR(-ENOMEM
);
209 CDEBUG(D_READA
, "alloc sa entry %.*s(%p) index %llu\n",
210 len
, name
, entry
, index
);
212 entry
->se_index
= index
;
215 * Statahead entry reference rules:
217 * 1) When statahead entry is initialized, its reference is set as 2.
218 * One reference is used by the directory scanner. When the scanner
219 * searches the statahead cache for the given name, it can perform
220 * lockless hash lookup (only the scanner can remove entry from hash
221 * list), and once found, it needn't to call "atomic_inc()" for the
222 * entry reference. So the performance is improved. After using the
223 * statahead entry, the scanner will call "atomic_dec()" to drop the
224 * reference held when initialization. If it is the last reference,
225 * the statahead entry will be freed.
227 * 2) All other threads, including statahead thread and ptlrpcd thread,
228 * when they process the statahead entry, the reference for target
229 * should be held to guarantee the entry will not be released by the
230 * directory scanner. After processing the entry, these threads will
231 * drop the entry reference. If it is the last reference, the entry
234 * The second reference when initializes the statahead entry is used
235 * by the statahead thread, following the rule 2).
237 atomic_set(&entry
->se_refcount
, 2);
238 entry
->se_stat
= SA_ENTRY_INIT
;
239 entry
->se_size
= entry_size
;
240 dname
= (char *)entry
+ sizeof(struct ll_sa_entry
);
241 memcpy(dname
, name
, len
);
243 entry
->se_qstr
.hash
= full_name_hash(name
, len
);
244 entry
->se_qstr
.len
= len
;
245 entry
->se_qstr
.name
= dname
;
247 lli
= ll_i2info(sai
->sai_inode
);
248 spin_lock(&lli
->lli_sa_lock
);
249 list_add_tail(&entry
->se_link
, &sai
->sai_entries
);
250 INIT_LIST_HEAD(&entry
->se_list
);
251 ll_sa_entry_enhash(sai
, entry
);
252 spin_unlock(&lli
->lli_sa_lock
);
254 atomic_inc(&sai
->sai_cache_count
);
260 * Used by the directory scanner to search entry with name.
262 * Only the caller can remove the entry from hash, so it is unnecessary to hold
263 * hash lock. It is caller's duty to release the init refcount on the entry, so
264 * it is also unnecessary to increase refcount on the entry.
266 static struct ll_sa_entry
*
267 ll_sa_entry_get_byname(struct ll_statahead_info
*sai
, const struct qstr
*qstr
)
269 struct ll_sa_entry
*entry
;
270 int i
= ll_sa_entry_hash(qstr
->hash
);
272 list_for_each_entry(entry
, &sai
->sai_cache
[i
], se_hash
) {
273 if (entry
->se_qstr
.hash
== qstr
->hash
&&
274 entry
->se_qstr
.len
== qstr
->len
&&
275 memcmp(entry
->se_qstr
.name
, qstr
->name
, qstr
->len
) == 0)
282 * Used by the async getattr request callback to find entry with index.
284 * Inside lli_sa_lock to prevent others to change the list during the search.
285 * It needs to increase entry refcount before returning to guarantee that the
286 * entry cannot be freed by others.
288 static struct ll_sa_entry
*
289 ll_sa_entry_get_byindex(struct ll_statahead_info
*sai
, __u64 index
)
291 struct ll_sa_entry
*entry
;
293 list_for_each_entry(entry
, &sai
->sai_entries
, se_link
) {
294 if (entry
->se_index
== index
) {
295 LASSERT(atomic_read(&entry
->se_refcount
) > 0);
296 atomic_inc(&entry
->se_refcount
);
299 if (entry
->se_index
> index
)
305 static void ll_sa_entry_cleanup(struct ll_statahead_info
*sai
,
306 struct ll_sa_entry
*entry
)
308 struct md_enqueue_info
*minfo
= entry
->se_minfo
;
309 struct ptlrpc_request
*req
= entry
->se_req
;
312 entry
->se_minfo
= NULL
;
313 ll_intent_release(&minfo
->mi_it
);
319 entry
->se_req
= NULL
;
320 ptlrpc_req_finished(req
);
324 static void ll_sa_entry_put(struct ll_statahead_info
*sai
,
325 struct ll_sa_entry
*entry
)
327 if (atomic_dec_and_test(&entry
->se_refcount
)) {
328 CDEBUG(D_READA
, "free sa entry %.*s(%p) index %llu\n",
329 entry
->se_qstr
.len
, entry
->se_qstr
.name
, entry
,
332 LASSERT(list_empty(&entry
->se_link
));
333 LASSERT(list_empty(&entry
->se_list
));
334 LASSERT(ll_sa_entry_unhashed(entry
));
336 ll_sa_entry_cleanup(sai
, entry
);
338 iput(entry
->se_inode
);
340 OBD_FREE(entry
, entry
->se_size
);
341 atomic_dec(&sai
->sai_cache_count
);
346 do_sa_entry_fini(struct ll_statahead_info
*sai
, struct ll_sa_entry
*entry
)
348 struct ll_inode_info
*lli
= ll_i2info(sai
->sai_inode
);
350 LASSERT(!ll_sa_entry_unhashed(entry
));
351 LASSERT(!list_empty(&entry
->se_link
));
353 ll_sa_entry_unhash(sai
, entry
);
355 spin_lock(&lli
->lli_sa_lock
);
356 entry
->se_stat
= SA_ENTRY_DEST
;
357 list_del_init(&entry
->se_link
);
358 if (likely(!list_empty(&entry
->se_list
)))
359 list_del_init(&entry
->se_list
);
360 spin_unlock(&lli
->lli_sa_lock
);
362 ll_sa_entry_put(sai
, entry
);
366 * Delete it from sai_entries_stated list when fini.
369 ll_sa_entry_fini(struct ll_statahead_info
*sai
, struct ll_sa_entry
*entry
)
371 struct ll_sa_entry
*pos
, *next
;
374 do_sa_entry_fini(sai
, entry
);
376 /* drop old entry, only 'scanner' process does this, no need to lock */
377 list_for_each_entry_safe(pos
, next
, &sai
->sai_entries
, se_link
) {
378 if (!is_omitted_entry(sai
, pos
->se_index
))
380 do_sa_entry_fini(sai
, pos
);
385 * Inside lli_sa_lock.
388 do_sa_entry_to_stated(struct ll_statahead_info
*sai
,
389 struct ll_sa_entry
*entry
, se_stat_t stat
)
391 struct ll_sa_entry
*se
;
392 struct list_head
*pos
= &sai
->sai_entries_stated
;
394 if (!list_empty(&entry
->se_list
))
395 list_del_init(&entry
->se_list
);
397 list_for_each_entry_reverse(se
, &sai
->sai_entries_stated
, se_list
) {
398 if (se
->se_index
< entry
->se_index
) {
404 list_add(&entry
->se_list
, pos
);
405 entry
->se_stat
= stat
;
409 * Move entry to sai_entries_stated and sort with the index.
410 * \retval 1 -- entry to be destroyed.
411 * \retval 0 -- entry is inserted into stated list.
414 ll_sa_entry_to_stated(struct ll_statahead_info
*sai
,
415 struct ll_sa_entry
*entry
, se_stat_t stat
)
417 struct ll_inode_info
*lli
= ll_i2info(sai
->sai_inode
);
420 ll_sa_entry_cleanup(sai
, entry
);
422 spin_lock(&lli
->lli_sa_lock
);
423 if (likely(entry
->se_stat
!= SA_ENTRY_DEST
)) {
424 do_sa_entry_to_stated(sai
, entry
, stat
);
427 spin_unlock(&lli
->lli_sa_lock
);
433 * Insert inode into the list of sai_entries_agl.
435 static void ll_agl_add(struct ll_statahead_info
*sai
,
436 struct inode
*inode
, int index
)
438 struct ll_inode_info
*child
= ll_i2info(inode
);
439 struct ll_inode_info
*parent
= ll_i2info(sai
->sai_inode
);
442 spin_lock(&child
->lli_agl_lock
);
443 if (child
->lli_agl_index
== 0) {
444 child
->lli_agl_index
= index
;
445 spin_unlock(&child
->lli_agl_lock
);
447 LASSERT(list_empty(&child
->lli_agl_list
));
450 spin_lock(&parent
->lli_agl_lock
);
451 if (agl_list_empty(sai
))
453 list_add_tail(&child
->lli_agl_list
, &sai
->sai_entries_agl
);
454 spin_unlock(&parent
->lli_agl_lock
);
456 spin_unlock(&child
->lli_agl_lock
);
460 wake_up(&sai
->sai_agl_thread
.t_ctl_waitq
);
463 static struct ll_statahead_info
*ll_sai_alloc(void)
465 struct ll_statahead_info
*sai
;
468 sai
= kzalloc(sizeof(*sai
), GFP_NOFS
);
472 atomic_set(&sai
->sai_refcount
, 1);
474 spin_lock(&sai_generation_lock
);
475 sai
->sai_generation
= ++sai_generation
;
476 if (unlikely(sai_generation
== 0))
477 sai
->sai_generation
= ++sai_generation
;
478 spin_unlock(&sai_generation_lock
);
480 sai
->sai_max
= LL_SA_RPC_MIN
;
482 init_waitqueue_head(&sai
->sai_waitq
);
483 init_waitqueue_head(&sai
->sai_thread
.t_ctl_waitq
);
484 init_waitqueue_head(&sai
->sai_agl_thread
.t_ctl_waitq
);
486 INIT_LIST_HEAD(&sai
->sai_entries
);
487 INIT_LIST_HEAD(&sai
->sai_entries_received
);
488 INIT_LIST_HEAD(&sai
->sai_entries_stated
);
489 INIT_LIST_HEAD(&sai
->sai_entries_agl
);
491 for (i
= 0; i
< LL_SA_CACHE_SIZE
; i
++) {
492 INIT_LIST_HEAD(&sai
->sai_cache
[i
]);
493 spin_lock_init(&sai
->sai_cache_lock
[i
]);
495 atomic_set(&sai
->sai_cache_count
, 0);
500 static inline struct ll_statahead_info
*
501 ll_sai_get(struct ll_statahead_info
*sai
)
503 atomic_inc(&sai
->sai_refcount
);
507 static void ll_sai_put(struct ll_statahead_info
*sai
)
509 struct inode
*inode
= sai
->sai_inode
;
510 struct ll_inode_info
*lli
= ll_i2info(inode
);
512 if (atomic_dec_and_lock(&sai
->sai_refcount
, &lli
->lli_sa_lock
)) {
513 struct ll_sa_entry
*entry
, *next
;
515 if (unlikely(atomic_read(&sai
->sai_refcount
) > 0)) {
516 /* It is race case, the interpret callback just hold
517 * a reference count */
518 spin_unlock(&lli
->lli_sa_lock
);
522 LASSERT(lli
->lli_opendir_key
== NULL
);
523 LASSERT(thread_is_stopped(&sai
->sai_thread
));
524 LASSERT(thread_is_stopped(&sai
->sai_agl_thread
));
527 lli
->lli_opendir_pid
= 0;
528 spin_unlock(&lli
->lli_sa_lock
);
530 if (sai
->sai_sent
> sai
->sai_replied
)
531 CDEBUG(D_READA
, "statahead for dir "DFID
532 " does not finish: [sent:%llu] [replied:%llu]\n",
534 sai
->sai_sent
, sai
->sai_replied
);
536 list_for_each_entry_safe(entry
, next
,
537 &sai
->sai_entries
, se_link
)
538 do_sa_entry_fini(sai
, entry
);
540 LASSERT(list_empty(&sai
->sai_entries
));
541 LASSERT(sa_received_empty(sai
));
542 LASSERT(list_empty(&sai
->sai_entries_stated
));
544 LASSERT(atomic_read(&sai
->sai_cache_count
) == 0);
545 LASSERT(agl_list_empty(sai
));
552 /* Do NOT forget to drop inode refcount when into sai_entries_agl. */
553 static void ll_agl_trigger(struct inode
*inode
, struct ll_statahead_info
*sai
)
555 struct ll_inode_info
*lli
= ll_i2info(inode
);
556 __u64 index
= lli
->lli_agl_index
;
559 LASSERT(list_empty(&lli
->lli_agl_list
));
561 /* AGL maybe fall behind statahead with one entry */
562 if (is_omitted_entry(sai
, index
+ 1)) {
563 lli
->lli_agl_index
= 0;
568 /* Someone is in glimpse (sync or async), do nothing. */
569 rc
= down_write_trylock(&lli
->lli_glimpse_sem
);
571 lli
->lli_agl_index
= 0;
577 * Someone triggered glimpse within 1 sec before.
578 * 1) The former glimpse succeeded with glimpse lock granted by OST, and
579 * if the lock is still cached on client, AGL needs to do nothing. If
580 * it is cancelled by other client, AGL maybe cannot obtain new lock
581 * for no glimpse callback triggered by AGL.
582 * 2) The former glimpse succeeded, but OST did not grant glimpse lock.
583 * Under such case, it is quite possible that the OST will not grant
584 * glimpse lock for AGL also.
585 * 3) The former glimpse failed, compared with other two cases, it is
586 * relative rare. AGL can ignore such case, and it will not muchly
587 * affect the performance.
589 if (lli
->lli_glimpse_time
!= 0 &&
590 time_before(cfs_time_shift(-1), lli
->lli_glimpse_time
)) {
591 up_write(&lli
->lli_glimpse_sem
);
592 lli
->lli_agl_index
= 0;
597 CDEBUG(D_READA
, "Handling (init) async glimpse: inode = "
598 DFID
", idx = %llu\n", PFID(&lli
->lli_fid
), index
);
601 lli
->lli_agl_index
= 0;
602 lli
->lli_glimpse_time
= cfs_time_current();
603 up_write(&lli
->lli_glimpse_sem
);
605 CDEBUG(D_READA
, "Handled (init) async glimpse: inode= "
606 DFID
", idx = %llu, rc = %d\n",
607 PFID(&lli
->lli_fid
), index
, rc
);
612 static void ll_post_statahead(struct ll_statahead_info
*sai
)
614 struct inode
*dir
= sai
->sai_inode
;
616 struct ll_inode_info
*lli
= ll_i2info(dir
);
617 struct ll_sa_entry
*entry
;
618 struct md_enqueue_info
*minfo
;
619 struct lookup_intent
*it
;
620 struct ptlrpc_request
*req
;
621 struct mdt_body
*body
;
624 spin_lock(&lli
->lli_sa_lock
);
625 if (unlikely(sa_received_empty(sai
))) {
626 spin_unlock(&lli
->lli_sa_lock
);
629 entry
= sa_first_received_entry(sai
);
630 atomic_inc(&entry
->se_refcount
);
631 list_del_init(&entry
->se_list
);
632 spin_unlock(&lli
->lli_sa_lock
);
634 LASSERT(entry
->se_handle
!= 0);
636 minfo
= entry
->se_minfo
;
639 body
= req_capsule_server_get(&req
->rq_pill
, &RMF_MDT_BODY
);
645 child
= entry
->se_inode
;
650 LASSERT(fid_is_zero(&minfo
->mi_data
.op_fid2
));
652 /* XXX: No fid in reply, this is probably cross-ref case.
653 * SA can't handle it yet. */
654 if (body
->valid
& OBD_MD_MDS
) {
662 /* unlinked and re-created with the same name */
663 if (unlikely(!lu_fid_eq(&minfo
->mi_data
.op_fid2
, &body
->fid1
))){
664 entry
->se_inode
= NULL
;
670 it
->d
.lustre
.it_lock_handle
= entry
->se_handle
;
671 rc
= md_revalidate_lock(ll_i2mdexp(dir
), it
, ll_inode2fid(dir
), NULL
);
677 rc
= ll_prep_inode(&child
, req
, dir
->i_sb
, it
);
681 CDEBUG(D_DLMTRACE
, "setting l_data to inode %p (%lu/%u)\n",
682 child
, child
->i_ino
, child
->i_generation
);
683 ll_set_lock_data(ll_i2sbi(dir
)->ll_md_exp
, child
, it
, NULL
);
685 entry
->se_inode
= child
;
687 if (agl_should_run(sai
, child
))
688 ll_agl_add(sai
, child
, entry
->se_index
);
691 /* The "ll_sa_entry_to_stated()" will drop related ldlm ibits lock
692 * reference count by calling "ll_intent_drop_lock()" in spite of the
693 * above operations failed or not. Do not worry about calling
694 * "ll_intent_drop_lock()" more than once. */
695 rc
= ll_sa_entry_to_stated(sai
, entry
,
696 rc
< 0 ? SA_ENTRY_INVA
: SA_ENTRY_SUCC
);
697 if (rc
== 0 && entry
->se_index
== sai
->sai_index_wait
)
698 wake_up(&sai
->sai_waitq
);
699 ll_sa_entry_put(sai
, entry
);
702 static int ll_statahead_interpret(struct ptlrpc_request
*req
,
703 struct md_enqueue_info
*minfo
, int rc
)
705 struct lookup_intent
*it
= &minfo
->mi_it
;
706 struct inode
*dir
= minfo
->mi_dir
;
707 struct ll_inode_info
*lli
= ll_i2info(dir
);
708 struct ll_statahead_info
*sai
= NULL
;
709 struct ll_sa_entry
*entry
;
712 if (it_disposition(it
, DISP_LOOKUP_NEG
))
715 spin_lock(&lli
->lli_sa_lock
);
717 if (unlikely(lli
->lli_sai
== NULL
||
718 lli
->lli_sai
->sai_generation
!= minfo
->mi_generation
)) {
719 spin_unlock(&lli
->lli_sa_lock
);
723 sai
= ll_sai_get(lli
->lli_sai
);
724 if (unlikely(!thread_is_running(&sai
->sai_thread
))) {
726 spin_unlock(&lli
->lli_sa_lock
);
731 entry
= ll_sa_entry_get_byindex(sai
, minfo
->mi_cbdata
);
734 spin_unlock(&lli
->lli_sa_lock
);
740 do_sa_entry_to_stated(sai
, entry
, SA_ENTRY_INVA
);
741 wakeup
= (entry
->se_index
== sai
->sai_index_wait
);
743 entry
->se_minfo
= minfo
;
744 entry
->se_req
= ptlrpc_request_addref(req
);
745 /* Release the async ibits lock ASAP to avoid deadlock
746 * when statahead thread tries to enqueue lock on parent
747 * for readpage and other tries to enqueue lock on child
748 * with parent's lock held, for example: unlink. */
749 entry
->se_handle
= it
->d
.lustre
.it_lock_handle
;
750 ll_intent_drop_lock(it
);
751 wakeup
= sa_received_empty(sai
);
752 list_add_tail(&entry
->se_list
,
753 &sai
->sai_entries_received
);
756 spin_unlock(&lli
->lli_sa_lock
);
758 ll_sa_entry_put(sai
, entry
);
760 wake_up(&sai
->sai_thread
.t_ctl_waitq
);
765 ll_intent_release(it
);
774 static void sa_args_fini(struct md_enqueue_info
*minfo
,
775 struct ldlm_enqueue_info
*einfo
)
777 LASSERT(minfo
&& einfo
);
779 capa_put(minfo
->mi_data
.op_capa1
);
780 capa_put(minfo
->mi_data
.op_capa2
);
786 * There is race condition between "capa_put" and "ll_statahead_interpret" for
787 * accessing "op_data.op_capa[1,2]" as following:
788 * "capa_put" releases "op_data.op_capa[1,2]"'s reference count after calling
789 * "md_intent_getattr_async". But "ll_statahead_interpret" maybe run first, and
790 * fill "op_data.op_capa[1,2]" as POISON, then cause "capa_put" access invalid
791 * "ocapa". So here reserve "op_data.op_capa[1,2]" in "pcapa" before calling
792 * "md_intent_getattr_async".
794 static int sa_args_init(struct inode
*dir
, struct inode
*child
,
795 struct ll_sa_entry
*entry
, struct md_enqueue_info
**pmi
,
796 struct ldlm_enqueue_info
**pei
,
797 struct obd_capa
**pcapa
)
799 struct qstr
*qstr
= &entry
->se_qstr
;
800 struct ll_inode_info
*lli
= ll_i2info(dir
);
801 struct md_enqueue_info
*minfo
;
802 struct ldlm_enqueue_info
*einfo
;
803 struct md_op_data
*op_data
;
805 einfo
= kzalloc(sizeof(*einfo
), GFP_NOFS
);
809 minfo
= kzalloc(sizeof(*minfo
), GFP_NOFS
);
815 op_data
= ll_prep_md_op_data(&minfo
->mi_data
, dir
, child
, qstr
->name
,
816 qstr
->len
, 0, LUSTRE_OPC_ANY
, NULL
);
817 if (IS_ERR(op_data
)) {
820 return PTR_ERR(op_data
);
823 minfo
->mi_it
.it_op
= IT_GETATTR
;
824 minfo
->mi_dir
= igrab(dir
);
825 minfo
->mi_cb
= ll_statahead_interpret
;
826 minfo
->mi_generation
= lli
->lli_sai
->sai_generation
;
827 minfo
->mi_cbdata
= entry
->se_index
;
829 einfo
->ei_type
= LDLM_IBITS
;
830 einfo
->ei_mode
= it_to_lock_mode(&minfo
->mi_it
);
831 einfo
->ei_cb_bl
= ll_md_blocking_ast
;
832 einfo
->ei_cb_cp
= ldlm_completion_ast
;
833 einfo
->ei_cb_gl
= NULL
;
834 einfo
->ei_cbdata
= NULL
;
838 pcapa
[0] = op_data
->op_capa1
;
839 pcapa
[1] = op_data
->op_capa2
;
844 static int do_sa_lookup(struct inode
*dir
, struct ll_sa_entry
*entry
)
846 struct md_enqueue_info
*minfo
;
847 struct ldlm_enqueue_info
*einfo
;
848 struct obd_capa
*capas
[2];
851 rc
= sa_args_init(dir
, NULL
, entry
, &minfo
, &einfo
, capas
);
855 rc
= md_intent_getattr_async(ll_i2mdexp(dir
), minfo
, einfo
);
860 sa_args_fini(minfo
, einfo
);
867 * similar to ll_revalidate_it().
868 * \retval 1 -- dentry valid
869 * \retval 0 -- will send stat-ahead request
870 * \retval others -- prepare stat-ahead request failed
872 static int do_sa_revalidate(struct inode
*dir
, struct ll_sa_entry
*entry
,
873 struct dentry
*dentry
)
875 struct inode
*inode
= dentry
->d_inode
;
876 struct lookup_intent it
= { .it_op
= IT_GETATTR
,
877 .d
.lustre
.it_lock_handle
= 0 };
878 struct md_enqueue_info
*minfo
;
879 struct ldlm_enqueue_info
*einfo
;
880 struct obd_capa
*capas
[2];
883 if (unlikely(inode
== NULL
))
886 if (d_mountpoint(dentry
))
889 entry
->se_inode
= igrab(inode
);
890 rc
= md_revalidate_lock(ll_i2mdexp(dir
), &it
, ll_inode2fid(inode
),
893 entry
->se_handle
= it
.d
.lustre
.it_lock_handle
;
894 ll_intent_release(&it
);
898 rc
= sa_args_init(dir
, inode
, entry
, &minfo
, &einfo
, capas
);
900 entry
->se_inode
= NULL
;
905 rc
= md_intent_getattr_async(ll_i2mdexp(dir
), minfo
, einfo
);
910 entry
->se_inode
= NULL
;
912 sa_args_fini(minfo
, einfo
);
918 static void ll_statahead_one(struct dentry
*parent
, const char* entry_name
,
921 struct inode
*dir
= parent
->d_inode
;
922 struct ll_inode_info
*lli
= ll_i2info(dir
);
923 struct ll_statahead_info
*sai
= lli
->lli_sai
;
924 struct dentry
*dentry
= NULL
;
925 struct ll_sa_entry
*entry
;
929 entry
= ll_sa_entry_alloc(sai
, sai
->sai_index
, entry_name
,
934 dentry
= d_lookup(parent
, &entry
->se_qstr
);
936 rc
= do_sa_lookup(dir
, entry
);
938 rc
= do_sa_revalidate(dir
, entry
, dentry
);
939 if (rc
== 1 && agl_should_run(sai
, dentry
->d_inode
))
940 ll_agl_add(sai
, dentry
->d_inode
, entry
->se_index
);
947 rc1
= ll_sa_entry_to_stated(sai
, entry
,
948 rc
< 0 ? SA_ENTRY_INVA
: SA_ENTRY_SUCC
);
949 if (rc1
== 0 && entry
->se_index
== sai
->sai_index_wait
)
950 wake_up(&sai
->sai_waitq
);
956 /* drop one refcount on entry by ll_sa_entry_alloc */
957 ll_sa_entry_put(sai
, entry
);
960 static int ll_agl_thread(void *arg
)
962 struct dentry
*parent
= (struct dentry
*)arg
;
963 struct inode
*dir
= parent
->d_inode
;
964 struct ll_inode_info
*plli
= ll_i2info(dir
);
965 struct ll_inode_info
*clli
;
966 struct ll_sb_info
*sbi
= ll_i2sbi(dir
);
967 struct ll_statahead_info
*sai
= ll_sai_get(plli
->lli_sai
);
968 struct ptlrpc_thread
*thread
= &sai
->sai_agl_thread
;
969 struct l_wait_info lwi
= { 0 };
971 thread
->t_pid
= current_pid();
972 CDEBUG(D_READA
, "agl thread started: sai %p, parent %.*s\n",
973 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
975 atomic_inc(&sbi
->ll_agl_total
);
976 spin_lock(&plli
->lli_agl_lock
);
977 sai
->sai_agl_valid
= 1;
978 if (thread_is_init(thread
))
979 /* If someone else has changed the thread state
980 * (e.g. already changed to SVC_STOPPING), we can't just
981 * blindly overwrite that setting. */
982 thread_set_flags(thread
, SVC_RUNNING
);
983 spin_unlock(&plli
->lli_agl_lock
);
984 wake_up(&thread
->t_ctl_waitq
);
987 l_wait_event(thread
->t_ctl_waitq
,
988 !agl_list_empty(sai
) ||
989 !thread_is_running(thread
),
992 if (!thread_is_running(thread
))
995 spin_lock(&plli
->lli_agl_lock
);
996 /* The statahead thread maybe help to process AGL entries,
997 * so check whether list empty again. */
998 if (!agl_list_empty(sai
)) {
999 clli
= agl_first_entry(sai
);
1000 list_del_init(&clli
->lli_agl_list
);
1001 spin_unlock(&plli
->lli_agl_lock
);
1002 ll_agl_trigger(&clli
->lli_vfs_inode
, sai
);
1004 spin_unlock(&plli
->lli_agl_lock
);
1008 spin_lock(&plli
->lli_agl_lock
);
1009 sai
->sai_agl_valid
= 0;
1010 while (!agl_list_empty(sai
)) {
1011 clli
= agl_first_entry(sai
);
1012 list_del_init(&clli
->lli_agl_list
);
1013 spin_unlock(&plli
->lli_agl_lock
);
1014 clli
->lli_agl_index
= 0;
1015 iput(&clli
->lli_vfs_inode
);
1016 spin_lock(&plli
->lli_agl_lock
);
1018 thread_set_flags(thread
, SVC_STOPPED
);
1019 spin_unlock(&plli
->lli_agl_lock
);
1020 wake_up(&thread
->t_ctl_waitq
);
1022 CDEBUG(D_READA
, "agl thread stopped: sai %p, parent %.*s\n",
1023 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
1027 static void ll_start_agl(struct dentry
*parent
, struct ll_statahead_info
*sai
)
1029 struct ptlrpc_thread
*thread
= &sai
->sai_agl_thread
;
1030 struct l_wait_info lwi
= { 0 };
1031 struct ll_inode_info
*plli
;
1032 struct task_struct
*task
;
1034 CDEBUG(D_READA
, "start agl thread: sai %p, parent %.*s\n",
1035 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
1037 plli
= ll_i2info(parent
->d_inode
);
1038 task
= kthread_run(ll_agl_thread
, parent
,
1039 "ll_agl_%u", plli
->lli_opendir_pid
);
1041 CERROR("can't start ll_agl thread, rc: %ld\n", PTR_ERR(task
));
1042 thread_set_flags(thread
, SVC_STOPPED
);
1046 l_wait_event(thread
->t_ctl_waitq
,
1047 thread_is_running(thread
) || thread_is_stopped(thread
),
1051 static int ll_statahead_thread(void *arg
)
1053 struct dentry
*parent
= (struct dentry
*)arg
;
1054 struct inode
*dir
= parent
->d_inode
;
1055 struct ll_inode_info
*plli
= ll_i2info(dir
);
1056 struct ll_inode_info
*clli
;
1057 struct ll_sb_info
*sbi
= ll_i2sbi(dir
);
1058 struct ll_statahead_info
*sai
= ll_sai_get(plli
->lli_sai
);
1059 struct ptlrpc_thread
*thread
= &sai
->sai_thread
;
1060 struct ptlrpc_thread
*agl_thread
= &sai
->sai_agl_thread
;
1065 struct ll_dir_chain chain
;
1066 struct l_wait_info lwi
= { 0 };
1068 thread
->t_pid
= current_pid();
1069 CDEBUG(D_READA
, "statahead thread starting: sai %p, parent %.*s\n",
1070 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
1072 if (sbi
->ll_flags
& LL_SBI_AGL_ENABLED
)
1073 ll_start_agl(parent
, sai
);
1075 atomic_inc(&sbi
->ll_sa_total
);
1076 spin_lock(&plli
->lli_sa_lock
);
1077 if (thread_is_init(thread
))
1078 /* If someone else has changed the thread state
1079 * (e.g. already changed to SVC_STOPPING), we can't just
1080 * blindly overwrite that setting. */
1081 thread_set_flags(thread
, SVC_RUNNING
);
1082 spin_unlock(&plli
->lli_sa_lock
);
1083 wake_up(&thread
->t_ctl_waitq
);
1085 ll_dir_chain_init(&chain
);
1086 page
= ll_get_dir_page(dir
, pos
, &chain
);
1089 struct lu_dirpage
*dp
;
1090 struct lu_dirent
*ent
;
1094 CDEBUG(D_READA
, "error reading dir "DFID
" at %llu/%llu: [rc %d] [parent %u]\n",
1095 PFID(ll_inode2fid(dir
)), pos
, sai
->sai_index
,
1096 rc
, plli
->lli_opendir_pid
);
1100 dp
= page_address(page
);
1101 for (ent
= lu_dirent_start(dp
); ent
!= NULL
;
1102 ent
= lu_dirent_next(ent
)) {
1107 hash
= le64_to_cpu(ent
->lde_hash
);
1108 if (unlikely(hash
< pos
))
1110 * Skip until we find target hash value.
1114 namelen
= le16_to_cpu(ent
->lde_namelen
);
1115 if (unlikely(namelen
== 0))
1117 * Skip dummy record.
1121 name
= ent
->lde_name
;
1122 if (name
[0] == '.') {
1128 } else if (name
[1] == '.' && namelen
== 2) {
1133 } else if (!sai
->sai_ls_all
) {
1135 * skip hidden files.
1137 sai
->sai_skip_hidden
++;
1143 * don't stat-ahead first entry.
1145 if (unlikely(++first
== 1))
1149 l_wait_event(thread
->t_ctl_waitq
,
1150 !sa_sent_full(sai
) ||
1151 !sa_received_empty(sai
) ||
1152 !agl_list_empty(sai
) ||
1153 !thread_is_running(thread
),
1157 while (!sa_received_empty(sai
))
1158 ll_post_statahead(sai
);
1160 if (unlikely(!thread_is_running(thread
))) {
1161 ll_release_page(page
, 0);
1166 /* If no window for metadata statahead, but there are
1167 * some AGL entries to be triggered, then try to help
1168 * to process the AGL entries. */
1169 if (sa_sent_full(sai
)) {
1170 spin_lock(&plli
->lli_agl_lock
);
1171 while (!agl_list_empty(sai
)) {
1172 clli
= agl_first_entry(sai
);
1173 list_del_init(&clli
->lli_agl_list
);
1174 spin_unlock(&plli
->lli_agl_lock
);
1175 ll_agl_trigger(&clli
->lli_vfs_inode
,
1178 if (!sa_received_empty(sai
))
1182 !thread_is_running(thread
))) {
1183 ll_release_page(page
, 0);
1188 if (!sa_sent_full(sai
))
1191 spin_lock(&plli
->lli_agl_lock
);
1193 spin_unlock(&plli
->lli_agl_lock
);
1199 ll_statahead_one(parent
, name
, namelen
);
1201 pos
= le64_to_cpu(dp
->ldp_hash_end
);
1202 if (pos
== MDS_DIR_END_OFF
) {
1204 * End of directory reached.
1206 ll_release_page(page
, 0);
1208 l_wait_event(thread
->t_ctl_waitq
,
1209 !sa_received_empty(sai
) ||
1210 sai
->sai_sent
== sai
->sai_replied
||
1211 !thread_is_running(thread
),
1214 while (!sa_received_empty(sai
))
1215 ll_post_statahead(sai
);
1217 if (unlikely(!thread_is_running(thread
))) {
1222 if (sai
->sai_sent
== sai
->sai_replied
&&
1223 sa_received_empty(sai
))
1227 spin_lock(&plli
->lli_agl_lock
);
1228 while (!agl_list_empty(sai
) &&
1229 thread_is_running(thread
)) {
1230 clli
= agl_first_entry(sai
);
1231 list_del_init(&clli
->lli_agl_list
);
1232 spin_unlock(&plli
->lli_agl_lock
);
1233 ll_agl_trigger(&clli
->lli_vfs_inode
, sai
);
1234 spin_lock(&plli
->lli_agl_lock
);
1236 spin_unlock(&plli
->lli_agl_lock
);
1242 * chain is exhausted.
1243 * Normal case: continue to the next page.
1245 ll_release_page(page
, le32_to_cpu(dp
->ldp_flags
) &
1247 page
= ll_get_dir_page(dir
, pos
, &chain
);
1249 LASSERT(le32_to_cpu(dp
->ldp_flags
) & LDF_COLLIDE
);
1250 ll_release_page(page
, 1);
1252 * go into overflow page.
1258 if (sai
->sai_agl_valid
) {
1259 spin_lock(&plli
->lli_agl_lock
);
1260 thread_set_flags(agl_thread
, SVC_STOPPING
);
1261 spin_unlock(&plli
->lli_agl_lock
);
1262 wake_up(&agl_thread
->t_ctl_waitq
);
1264 CDEBUG(D_READA
, "stop agl thread: sai %p pid %u\n",
1265 sai
, (unsigned int)agl_thread
->t_pid
);
1266 l_wait_event(agl_thread
->t_ctl_waitq
,
1267 thread_is_stopped(agl_thread
),
1270 /* Set agl_thread flags anyway. */
1271 thread_set_flags(&sai
->sai_agl_thread
, SVC_STOPPED
);
1273 ll_dir_chain_fini(&chain
);
1274 spin_lock(&plli
->lli_sa_lock
);
1275 if (!sa_received_empty(sai
)) {
1276 thread_set_flags(thread
, SVC_STOPPING
);
1277 spin_unlock(&plli
->lli_sa_lock
);
1279 /* To release the resources held by received entries. */
1280 while (!sa_received_empty(sai
))
1281 ll_post_statahead(sai
);
1283 spin_lock(&plli
->lli_sa_lock
);
1285 thread_set_flags(thread
, SVC_STOPPED
);
1286 spin_unlock(&plli
->lli_sa_lock
);
1287 wake_up(&sai
->sai_waitq
);
1288 wake_up(&thread
->t_ctl_waitq
);
1291 CDEBUG(D_READA
, "statahead thread stopped: sai %p, parent %.*s\n",
1292 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
1297 * called in ll_file_release().
1299 void ll_stop_statahead(struct inode
*dir
, void *key
)
1301 struct ll_inode_info
*lli
= ll_i2info(dir
);
1303 if (unlikely(key
== NULL
))
1306 spin_lock(&lli
->lli_sa_lock
);
1307 if (lli
->lli_opendir_key
!= key
|| lli
->lli_opendir_pid
== 0) {
1308 spin_unlock(&lli
->lli_sa_lock
);
1312 lli
->lli_opendir_key
= NULL
;
1315 struct l_wait_info lwi
= { 0 };
1316 struct ptlrpc_thread
*thread
= &lli
->lli_sai
->sai_thread
;
1318 if (!thread_is_stopped(thread
)) {
1319 thread_set_flags(thread
, SVC_STOPPING
);
1320 spin_unlock(&lli
->lli_sa_lock
);
1321 wake_up(&thread
->t_ctl_waitq
);
1323 CDEBUG(D_READA
, "stop statahead thread: sai %p pid %u\n",
1324 lli
->lli_sai
, (unsigned int)thread
->t_pid
);
1325 l_wait_event(thread
->t_ctl_waitq
,
1326 thread_is_stopped(thread
),
1329 spin_unlock(&lli
->lli_sa_lock
);
1333 * Put the ref which was held when first statahead_enter.
1334 * It maybe not the last ref for some statahead requests
1337 ll_sai_put(lli
->lli_sai
);
1339 lli
->lli_opendir_pid
= 0;
1340 spin_unlock(&lli
->lli_sa_lock
);
1346 * not first dirent, or is "."
1348 LS_NONE_FIRST_DE
= 0,
1350 * the first non-hidden dirent
1354 * the first hidden dirent, that is "."
1359 static int is_first_dirent(struct inode
*dir
, struct dentry
*dentry
)
1361 struct ll_dir_chain chain
;
1362 struct qstr
*target
= &dentry
->d_name
;
1366 int rc
= LS_NONE_FIRST_DE
;
1368 ll_dir_chain_init(&chain
);
1369 page
= ll_get_dir_page(dir
, pos
, &chain
);
1372 struct lu_dirpage
*dp
;
1373 struct lu_dirent
*ent
;
1376 struct ll_inode_info
*lli
= ll_i2info(dir
);
1379 CERROR("error reading dir "DFID
" at %llu: [rc %d] [parent %u]\n",
1380 PFID(ll_inode2fid(dir
)), pos
,
1381 rc
, lli
->lli_opendir_pid
);
1385 dp
= page_address(page
);
1386 for (ent
= lu_dirent_start(dp
); ent
!= NULL
;
1387 ent
= lu_dirent_next(ent
)) {
1392 hash
= le64_to_cpu(ent
->lde_hash
);
1393 /* The ll_get_dir_page() can return any page containing
1394 * the given hash which may be not the start hash. */
1395 if (unlikely(hash
< pos
))
1398 namelen
= le16_to_cpu(ent
->lde_namelen
);
1399 if (unlikely(namelen
== 0))
1401 * skip dummy record.
1405 name
= ent
->lde_name
;
1406 if (name
[0] == '.') {
1412 else if (name
[1] == '.' && namelen
== 2)
1423 if (dot_de
&& target
->name
[0] != '.') {
1424 CDEBUG(D_READA
, "%.*s skip hidden file %.*s\n",
1425 target
->len
, target
->name
,
1430 if (target
->len
!= namelen
||
1431 memcmp(target
->name
, name
, namelen
) != 0)
1432 rc
= LS_NONE_FIRST_DE
;
1436 rc
= LS_FIRST_DOT_DE
;
1438 ll_release_page(page
, 0);
1441 pos
= le64_to_cpu(dp
->ldp_hash_end
);
1442 if (pos
== MDS_DIR_END_OFF
) {
1444 * End of directory reached.
1446 ll_release_page(page
, 0);
1450 * chain is exhausted
1451 * Normal case: continue to the next page.
1453 ll_release_page(page
, le32_to_cpu(dp
->ldp_flags
) &
1455 page
= ll_get_dir_page(dir
, pos
, &chain
);
1458 * go into overflow page.
1460 LASSERT(le32_to_cpu(dp
->ldp_flags
) & LDF_COLLIDE
);
1461 ll_release_page(page
, 1);
1466 ll_dir_chain_fini(&chain
);
1471 ll_sai_unplug(struct ll_statahead_info
*sai
, struct ll_sa_entry
*entry
)
1473 struct ptlrpc_thread
*thread
= &sai
->sai_thread
;
1474 struct ll_sb_info
*sbi
= ll_i2sbi(sai
->sai_inode
);
1477 if (entry
!= NULL
&& entry
->se_stat
== SA_ENTRY_SUCC
)
1482 ll_sa_entry_fini(sai
, entry
);
1485 sai
->sai_consecutive_miss
= 0;
1486 sai
->sai_max
= min(2 * sai
->sai_max
, sbi
->ll_sa_max
);
1488 struct ll_inode_info
*lli
= ll_i2info(sai
->sai_inode
);
1491 sai
->sai_consecutive_miss
++;
1492 if (sa_low_hit(sai
) && thread_is_running(thread
)) {
1493 atomic_inc(&sbi
->ll_sa_wrong
);
1494 CDEBUG(D_READA
, "Statahead for dir "DFID
" hit "
1495 "ratio too low: hit/miss %llu/%llu"
1496 ", sent/replied %llu/%llu, stopping "
1497 "statahead thread\n",
1498 PFID(&lli
->lli_fid
), sai
->sai_hit
,
1499 sai
->sai_miss
, sai
->sai_sent
,
1501 spin_lock(&lli
->lli_sa_lock
);
1502 if (!thread_is_stopped(thread
))
1503 thread_set_flags(thread
, SVC_STOPPING
);
1504 spin_unlock(&lli
->lli_sa_lock
);
1508 if (!thread_is_stopped(thread
))
1509 wake_up(&thread
->t_ctl_waitq
);
1513 * Start statahead thread if this is the first dir entry.
1514 * Otherwise if a thread is started already, wait it until it is ahead of me.
1515 * \retval 1 -- find entry with lock in cache, the caller needs to do
1517 * \retval 0 -- find entry in cache, but without lock, the caller needs
1519 * \retval others -- the caller need to process as non-statahead.
1521 int do_statahead_enter(struct inode
*dir
, struct dentry
**dentryp
,
1524 struct ll_inode_info
*lli
= ll_i2info(dir
);
1525 struct ll_statahead_info
*sai
= lli
->lli_sai
;
1526 struct dentry
*parent
;
1527 struct ll_sa_entry
*entry
;
1528 struct ptlrpc_thread
*thread
;
1529 struct l_wait_info lwi
= { 0 };
1531 struct ll_inode_info
*plli
;
1533 LASSERT(lli
->lli_opendir_pid
== current_pid());
1536 thread
= &sai
->sai_thread
;
1537 if (unlikely(thread_is_stopped(thread
) &&
1538 list_empty(&sai
->sai_entries_stated
))) {
1539 /* to release resource */
1540 ll_stop_statahead(dir
, lli
->lli_opendir_key
);
1544 if ((*dentryp
)->d_name
.name
[0] == '.') {
1545 if (sai
->sai_ls_all
||
1546 sai
->sai_miss_hidden
>= sai
->sai_skip_hidden
) {
1548 * Hidden dentry is the first one, or statahead
1549 * thread does not skip so many hidden dentries
1550 * before "sai_ls_all" enabled as below.
1553 if (!sai
->sai_ls_all
)
1555 * It maybe because hidden dentry is not
1556 * the first one, "sai_ls_all" was not
1557 * set, then "ls -al" missed. Enable
1558 * "sai_ls_all" for such case.
1560 sai
->sai_ls_all
= 1;
1563 * Such "getattr" has been skipped before
1564 * "sai_ls_all" enabled as above.
1566 sai
->sai_miss_hidden
++;
1571 entry
= ll_sa_entry_get_byname(sai
, &(*dentryp
)->d_name
);
1572 if (entry
== NULL
|| only_unplug
) {
1573 ll_sai_unplug(sai
, entry
);
1574 return entry
? 1 : -EAGAIN
;
1577 if (!ll_sa_entry_stated(entry
)) {
1578 sai
->sai_index_wait
= entry
->se_index
;
1579 lwi
= LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL
,
1580 LWI_ON_SIGNAL_NOOP
, NULL
);
1581 rc
= l_wait_event(sai
->sai_waitq
,
1582 ll_sa_entry_stated(entry
) ||
1583 thread_is_stopped(thread
),
1586 ll_sai_unplug(sai
, entry
);
1591 if (entry
->se_stat
== SA_ENTRY_SUCC
&&
1592 entry
->se_inode
!= NULL
) {
1593 struct inode
*inode
= entry
->se_inode
;
1594 struct lookup_intent it
= { .it_op
= IT_GETATTR
,
1595 .d
.lustre
.it_lock_handle
=
1599 rc
= md_revalidate_lock(ll_i2mdexp(dir
), &it
,
1600 ll_inode2fid(inode
), &bits
);
1602 if ((*dentryp
)->d_inode
== NULL
) {
1603 struct dentry
*alias
;
1605 alias
= ll_splice_alias(inode
,
1607 if (IS_ERR(alias
)) {
1608 ll_sai_unplug(sai
, entry
);
1609 return PTR_ERR(alias
);
1612 } else if ((*dentryp
)->d_inode
!= inode
) {
1613 /* revalidate, but inode is recreated */
1615 "stale dentry %.*s inode %lu/%u, "
1616 "statahead inode %lu/%u\n",
1617 (*dentryp
)->d_name
.len
,
1618 (*dentryp
)->d_name
.name
,
1619 (*dentryp
)->d_inode
->i_ino
,
1620 (*dentryp
)->d_inode
->i_generation
,
1622 inode
->i_generation
);
1623 ll_sai_unplug(sai
, entry
);
1628 entry
->se_inode
= NULL
;
1630 if ((bits
& MDS_INODELOCK_LOOKUP
) &&
1631 d_lustre_invalid(*dentryp
))
1632 d_lustre_revalidate(*dentryp
);
1633 ll_intent_release(&it
);
1637 ll_sai_unplug(sai
, entry
);
1641 /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
1642 rc
= is_first_dirent(dir
, *dentryp
);
1643 if (rc
== LS_NONE_FIRST_DE
) {
1644 /* It is not "ls -{a}l" operation, no need statahead for it. */
1649 sai
= ll_sai_alloc();
1655 sai
->sai_ls_all
= (rc
== LS_FIRST_DOT_DE
);
1656 sai
->sai_inode
= igrab(dir
);
1657 if (unlikely(sai
->sai_inode
== NULL
)) {
1658 CWARN("Do not start stat ahead on dying inode "DFID
"\n",
1659 PFID(&lli
->lli_fid
));
1664 /* get parent reference count here, and put it in ll_statahead_thread */
1665 parent
= dget((*dentryp
)->d_parent
);
1666 if (unlikely(sai
->sai_inode
!= parent
->d_inode
)) {
1667 struct ll_inode_info
*nlli
= ll_i2info(parent
->d_inode
);
1669 CWARN("Race condition, someone changed %.*s just now: "
1670 "old parent "DFID
", new parent "DFID
"\n",
1671 (*dentryp
)->d_name
.len
, (*dentryp
)->d_name
.name
,
1672 PFID(&lli
->lli_fid
), PFID(&nlli
->lli_fid
));
1674 iput(sai
->sai_inode
);
1679 CDEBUG(D_READA
, "start statahead thread: sai %p, parent %.*s\n",
1680 sai
, parent
->d_name
.len
, parent
->d_name
.name
);
1682 /* The sai buffer already has one reference taken at allocation time,
1683 * but as soon as we expose the sai by attaching it to the lli that
1684 * default reference can be dropped by another thread calling
1685 * ll_stop_statahead. We need to take a local reference to protect
1686 * the sai buffer while we intend to access it. */
1690 plli
= ll_i2info(parent
->d_inode
);
1691 rc
= PTR_ERR(kthread_run(ll_statahead_thread
, parent
,
1692 "ll_sa_%u", plli
->lli_opendir_pid
));
1693 thread
= &sai
->sai_thread
;
1694 if (IS_ERR_VALUE(rc
)) {
1695 CERROR("can't start ll_sa thread, rc: %d\n", rc
);
1697 lli
->lli_opendir_key
= NULL
;
1698 thread_set_flags(thread
, SVC_STOPPED
);
1699 thread_set_flags(&sai
->sai_agl_thread
, SVC_STOPPED
);
1700 /* Drop both our own local reference and the default
1701 * reference from allocation time. */
1704 LASSERT(lli
->lli_sai
== NULL
);
1708 l_wait_event(thread
->t_ctl_waitq
,
1709 thread_is_running(thread
) || thread_is_stopped(thread
),
1714 * We don't stat-ahead for the first dirent since we are already in
1722 spin_lock(&lli
->lli_sa_lock
);
1723 lli
->lli_opendir_key
= NULL
;
1724 lli
->lli_opendir_pid
= 0;
1725 spin_unlock(&lli
->lli_sa_lock
);