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 <obd_support.h>
46 #include <lustre_lite.h>
47 #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 OBD_ALLOC(entry, entry_size);
206 if (unlikely(entry == NULL))
207 return ERR_PTR(-ENOMEM);
209 CDEBUG(D_READA, "alloc sa entry %.*s(%p) index "LPU64"\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 "LPU64"\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;
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" does not "
532 "finish: [sent:"LPU64"] [replied:"LPU64"]\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 obtaion 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 cfs_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 = "LPU64"\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 = "LPU64", 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);
641 GOTO(out, rc = -EFAULT);
643 child = entry->se_inode;
648 LASSERT(fid_is_zero(&minfo->mi_data.op_fid2));
650 /* XXX: No fid in reply, this is probably cross-ref case.
651 * SA can't handle it yet. */
652 if (body->valid & OBD_MD_MDS)
653 GOTO(out, rc = -EAGAIN);
658 /* unlinked and re-created with the same name */
659 if (unlikely(!lu_fid_eq(&minfo->mi_data.op_fid2, &body->fid1))){
660 entry->se_inode = NULL;
666 it->d.lustre.it_lock_handle = entry->se_handle;
667 rc = md_revalidate_lock(ll_i2mdexp(dir), it, ll_inode2fid(dir), NULL);
669 GOTO(out, rc = -EAGAIN);
671 rc = ll_prep_inode(&child, req, dir->i_sb, it);
675 CDEBUG(D_DLMTRACE, "setting l_data to inode %p (%lu/%u)\n",
676 child, child->i_ino, child->i_generation);
677 ll_set_lock_data(ll_i2sbi(dir)->ll_md_exp, child, it, NULL);
679 entry->se_inode = child;
681 if (agl_should_run(sai, child))
682 ll_agl_add(sai, child, entry->se_index);
685 /* The "ll_sa_entry_to_stated()" will drop related ldlm ibits lock
686 * reference count by calling "ll_intent_drop_lock()" in spite of the
687 * above operations failed or not. Do not worry about calling
688 * "ll_intent_drop_lock()" more than once. */
689 rc = ll_sa_entry_to_stated(sai, entry,
690 rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
691 if (rc == 0 && entry->se_index == sai->sai_index_wait)
692 wake_up(&sai->sai_waitq);
693 ll_sa_entry_put(sai, entry);
696 static int ll_statahead_interpret(struct ptlrpc_request *req,
697 struct md_enqueue_info *minfo, int rc)
699 struct lookup_intent *it = &minfo->mi_it;
700 struct inode *dir = minfo->mi_dir;
701 struct ll_inode_info *lli = ll_i2info(dir);
702 struct ll_statahead_info *sai = NULL;
703 struct ll_sa_entry *entry;
706 if (it_disposition(it, DISP_LOOKUP_NEG))
709 spin_lock(&lli->lli_sa_lock);
711 if (unlikely(lli->lli_sai == NULL ||
712 lli->lli_sai->sai_generation != minfo->mi_generation)) {
713 spin_unlock(&lli->lli_sa_lock);
714 GOTO(out, rc = -ESTALE);
716 sai = ll_sai_get(lli->lli_sai);
717 if (unlikely(!thread_is_running(&sai->sai_thread))) {
719 spin_unlock(&lli->lli_sa_lock);
720 GOTO(out, rc = -EBADFD);
723 entry = ll_sa_entry_get_byindex(sai, minfo->mi_cbdata);
726 spin_unlock(&lli->lli_sa_lock);
727 GOTO(out, rc = -EIDRM);
731 do_sa_entry_to_stated(sai, entry, SA_ENTRY_INVA);
732 wakeup = (entry->se_index == sai->sai_index_wait);
734 entry->se_minfo = minfo;
735 entry->se_req = ptlrpc_request_addref(req);
736 /* Release the async ibits lock ASAP to avoid deadlock
737 * when statahead thread tries to enqueue lock on parent
738 * for readpage and other tries to enqueue lock on child
739 * with parent's lock held, for example: unlink. */
740 entry->se_handle = it->d.lustre.it_lock_handle;
741 ll_intent_drop_lock(it);
742 wakeup = sa_received_empty(sai);
743 list_add_tail(&entry->se_list,
744 &sai->sai_entries_received);
747 spin_unlock(&lli->lli_sa_lock);
749 ll_sa_entry_put(sai, entry);
751 wake_up(&sai->sai_thread.t_ctl_waitq);
756 ll_intent_release(it);
765 static void sa_args_fini(struct md_enqueue_info *minfo,
766 struct ldlm_enqueue_info *einfo)
768 LASSERT(minfo && einfo);
770 capa_put(minfo->mi_data.op_capa1);
771 capa_put(minfo->mi_data.op_capa2);
777 * There is race condition between "capa_put" and "ll_statahead_interpret" for
778 * accessing "op_data.op_capa[1,2]" as following:
779 * "capa_put" releases "op_data.op_capa[1,2]"'s reference count after calling
780 * "md_intent_getattr_async". But "ll_statahead_interpret" maybe run first, and
781 * fill "op_data.op_capa[1,2]" as POISON, then cause "capa_put" access invalid
782 * "ocapa". So here reserve "op_data.op_capa[1,2]" in "pcapa" before calling
783 * "md_intent_getattr_async".
785 static int sa_args_init(struct inode *dir, struct inode *child,
786 struct ll_sa_entry *entry, struct md_enqueue_info **pmi,
787 struct ldlm_enqueue_info **pei,
788 struct obd_capa **pcapa)
790 struct qstr *qstr = &entry->se_qstr;
791 struct ll_inode_info *lli = ll_i2info(dir);
792 struct md_enqueue_info *minfo;
793 struct ldlm_enqueue_info *einfo;
794 struct md_op_data *op_data;
796 OBD_ALLOC_PTR(einfo);
800 OBD_ALLOC_PTR(minfo);
806 op_data = ll_prep_md_op_data(&minfo->mi_data, dir, child, qstr->name,
807 qstr->len, 0, LUSTRE_OPC_ANY, NULL);
808 if (IS_ERR(op_data)) {
811 return PTR_ERR(op_data);
814 minfo->mi_it.it_op = IT_GETATTR;
815 minfo->mi_dir = igrab(dir);
816 minfo->mi_cb = ll_statahead_interpret;
817 minfo->mi_generation = lli->lli_sai->sai_generation;
818 minfo->mi_cbdata = entry->se_index;
820 einfo->ei_type = LDLM_IBITS;
821 einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
822 einfo->ei_cb_bl = ll_md_blocking_ast;
823 einfo->ei_cb_cp = ldlm_completion_ast;
824 einfo->ei_cb_gl = NULL;
825 einfo->ei_cbdata = NULL;
829 pcapa[0] = op_data->op_capa1;
830 pcapa[1] = op_data->op_capa2;
835 static int do_sa_lookup(struct inode *dir, struct ll_sa_entry *entry)
837 struct md_enqueue_info *minfo;
838 struct ldlm_enqueue_info *einfo;
839 struct obd_capa *capas[2];
842 rc = sa_args_init(dir, NULL, entry, &minfo, &einfo, capas);
846 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
851 sa_args_fini(minfo, einfo);
858 * similar to ll_revalidate_it().
859 * \retval 1 -- dentry valid
860 * \retval 0 -- will send stat-ahead request
861 * \retval others -- prepare stat-ahead request failed
863 static int do_sa_revalidate(struct inode *dir, struct ll_sa_entry *entry,
864 struct dentry *dentry)
866 struct inode *inode = dentry->d_inode;
867 struct lookup_intent it = { .it_op = IT_GETATTR,
868 .d.lustre.it_lock_handle = 0 };
869 struct md_enqueue_info *minfo;
870 struct ldlm_enqueue_info *einfo;
871 struct obd_capa *capas[2];
874 if (unlikely(inode == NULL))
877 if (d_mountpoint(dentry))
880 if (unlikely(dentry == dentry->d_sb->s_root))
883 entry->se_inode = igrab(inode);
884 rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode),NULL);
886 entry->se_handle = it.d.lustre.it_lock_handle;
887 ll_intent_release(&it);
891 rc = sa_args_init(dir, inode, entry, &minfo, &einfo, capas);
893 entry->se_inode = NULL;
898 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
903 entry->se_inode = NULL;
905 sa_args_fini(minfo, einfo);
911 static void ll_statahead_one(struct dentry *parent, const char* entry_name,
914 struct inode *dir = parent->d_inode;
915 struct ll_inode_info *lli = ll_i2info(dir);
916 struct ll_statahead_info *sai = lli->lli_sai;
917 struct dentry *dentry = NULL;
918 struct ll_sa_entry *entry;
922 entry = ll_sa_entry_alloc(sai, sai->sai_index, entry_name,
927 dentry = d_lookup(parent, &entry->se_qstr);
929 rc = do_sa_lookup(dir, entry);
931 rc = do_sa_revalidate(dir, entry, dentry);
932 if (rc == 1 && agl_should_run(sai, dentry->d_inode))
933 ll_agl_add(sai, dentry->d_inode, entry->se_index);
940 rc1 = ll_sa_entry_to_stated(sai, entry,
941 rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
942 if (rc1 == 0 && entry->se_index == sai->sai_index_wait)
943 wake_up(&sai->sai_waitq);
949 /* drop one refcount on entry by ll_sa_entry_alloc */
950 ll_sa_entry_put(sai, entry);
953 static int ll_agl_thread(void *arg)
955 struct dentry *parent = (struct dentry *)arg;
956 struct inode *dir = parent->d_inode;
957 struct ll_inode_info *plli = ll_i2info(dir);
958 struct ll_inode_info *clli;
959 struct ll_sb_info *sbi = ll_i2sbi(dir);
960 struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai);
961 struct ptlrpc_thread *thread = &sai->sai_agl_thread;
962 struct l_wait_info lwi = { 0 };
964 CDEBUG(D_READA, "agl thread started: [pid %d] [parent %.*s]\n",
965 current_pid(), parent->d_name.len, parent->d_name.name);
967 atomic_inc(&sbi->ll_agl_total);
968 spin_lock(&plli->lli_agl_lock);
969 sai->sai_agl_valid = 1;
970 thread_set_flags(thread, SVC_RUNNING);
971 spin_unlock(&plli->lli_agl_lock);
972 wake_up(&thread->t_ctl_waitq);
975 l_wait_event(thread->t_ctl_waitq,
976 !agl_list_empty(sai) ||
977 !thread_is_running(thread),
980 if (!thread_is_running(thread))
983 spin_lock(&plli->lli_agl_lock);
984 /* The statahead thread maybe help to process AGL entries,
985 * so check whether list empty again. */
986 if (!agl_list_empty(sai)) {
987 clli = agl_first_entry(sai);
988 list_del_init(&clli->lli_agl_list);
989 spin_unlock(&plli->lli_agl_lock);
990 ll_agl_trigger(&clli->lli_vfs_inode, sai);
992 spin_unlock(&plli->lli_agl_lock);
996 spin_lock(&plli->lli_agl_lock);
997 sai->sai_agl_valid = 0;
998 while (!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 clli->lli_agl_index = 0;
1003 iput(&clli->lli_vfs_inode);
1004 spin_lock(&plli->lli_agl_lock);
1006 thread_set_flags(thread, SVC_STOPPED);
1007 spin_unlock(&plli->lli_agl_lock);
1008 wake_up(&thread->t_ctl_waitq);
1010 CDEBUG(D_READA, "agl thread stopped: [pid %d] [parent %.*s]\n",
1011 current_pid(), parent->d_name.len, parent->d_name.name);
1015 static void ll_start_agl(struct dentry *parent, struct ll_statahead_info *sai)
1017 struct ptlrpc_thread *thread = &sai->sai_agl_thread;
1018 struct l_wait_info lwi = { 0 };
1019 struct ll_inode_info *plli;
1020 struct task_struct *task;
1022 CDEBUG(D_READA, "start agl thread: [pid %d] [parent %.*s]\n",
1023 current_pid(), parent->d_name.len, parent->d_name.name);
1025 plli = ll_i2info(parent->d_inode);
1026 task = kthread_run(ll_agl_thread, parent,
1027 "ll_agl_%u", plli->lli_opendir_pid);
1029 CERROR("can't start ll_agl thread, rc: %ld\n", PTR_ERR(task));
1030 thread_set_flags(thread, SVC_STOPPED);
1034 l_wait_event(thread->t_ctl_waitq,
1035 thread_is_running(thread) || thread_is_stopped(thread),
1039 static int ll_statahead_thread(void *arg)
1041 struct dentry *parent = (struct dentry *)arg;
1042 struct inode *dir = parent->d_inode;
1043 struct ll_inode_info *plli = ll_i2info(dir);
1044 struct ll_inode_info *clli;
1045 struct ll_sb_info *sbi = ll_i2sbi(dir);
1046 struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai);
1047 struct ptlrpc_thread *thread = &sai->sai_thread;
1048 struct ptlrpc_thread *agl_thread = &sai->sai_agl_thread;
1053 struct ll_dir_chain chain;
1054 struct l_wait_info lwi = { 0 };
1056 CDEBUG(D_READA, "statahead thread started: [pid %d] [parent %.*s]\n",
1057 current_pid(), parent->d_name.len, parent->d_name.name);
1059 if (sbi->ll_flags & LL_SBI_AGL_ENABLED)
1060 ll_start_agl(parent, sai);
1062 atomic_inc(&sbi->ll_sa_total);
1063 spin_lock(&plli->lli_sa_lock);
1064 thread_set_flags(thread, SVC_RUNNING);
1065 spin_unlock(&plli->lli_sa_lock);
1066 wake_up(&thread->t_ctl_waitq);
1068 ll_dir_chain_init(&chain);
1069 page = ll_get_dir_page(dir, pos, &chain);
1072 struct lu_dirpage *dp;
1073 struct lu_dirent *ent;
1077 CDEBUG(D_READA, "error reading dir "DFID" at "LPU64
1078 "/"LPU64": [rc %d] [parent %u]\n",
1079 PFID(ll_inode2fid(dir)), pos, sai->sai_index,
1080 rc, plli->lli_opendir_pid);
1084 dp = page_address(page);
1085 for (ent = lu_dirent_start(dp); ent != NULL;
1086 ent = lu_dirent_next(ent)) {
1091 hash = le64_to_cpu(ent->lde_hash);
1092 if (unlikely(hash < pos))
1094 * Skip until we find target hash value.
1098 namelen = le16_to_cpu(ent->lde_namelen);
1099 if (unlikely(namelen == 0))
1101 * Skip dummy record.
1105 name = ent->lde_name;
1106 if (name[0] == '.') {
1112 } else if (name[1] == '.' && namelen == 2) {
1117 } else if (!sai->sai_ls_all) {
1119 * skip hidden files.
1121 sai->sai_skip_hidden++;
1127 * don't stat-ahead first entry.
1129 if (unlikely(++first == 1))
1133 l_wait_event(thread->t_ctl_waitq,
1134 !sa_sent_full(sai) ||
1135 !sa_received_empty(sai) ||
1136 !agl_list_empty(sai) ||
1137 !thread_is_running(thread),
1141 while (!sa_received_empty(sai))
1142 ll_post_statahead(sai);
1144 if (unlikely(!thread_is_running(thread))) {
1145 ll_release_page(page, 0);
1149 /* If no window for metadata statahead, but there are
1150 * some AGL entries to be triggered, then try to help
1151 * to process the AGL entries. */
1152 if (sa_sent_full(sai)) {
1153 spin_lock(&plli->lli_agl_lock);
1154 while (!agl_list_empty(sai)) {
1155 clli = agl_first_entry(sai);
1156 list_del_init(&clli->lli_agl_list);
1157 spin_unlock(&plli->lli_agl_lock);
1158 ll_agl_trigger(&clli->lli_vfs_inode,
1161 if (!sa_received_empty(sai))
1165 !thread_is_running(thread))) {
1166 ll_release_page(page, 0);
1170 if (!sa_sent_full(sai))
1173 spin_lock(&plli->lli_agl_lock);
1175 spin_unlock(&plli->lli_agl_lock);
1181 ll_statahead_one(parent, name, namelen);
1183 pos = le64_to_cpu(dp->ldp_hash_end);
1184 if (pos == MDS_DIR_END_OFF) {
1186 * End of directory reached.
1188 ll_release_page(page, 0);
1190 l_wait_event(thread->t_ctl_waitq,
1191 !sa_received_empty(sai) ||
1192 sai->sai_sent == sai->sai_replied||
1193 !thread_is_running(thread),
1196 while (!sa_received_empty(sai))
1197 ll_post_statahead(sai);
1199 if (unlikely(!thread_is_running(thread)))
1202 if (sai->sai_sent == sai->sai_replied &&
1203 sa_received_empty(sai))
1207 spin_lock(&plli->lli_agl_lock);
1208 while (!agl_list_empty(sai) &&
1209 thread_is_running(thread)) {
1210 clli = agl_first_entry(sai);
1211 list_del_init(&clli->lli_agl_list);
1212 spin_unlock(&plli->lli_agl_lock);
1213 ll_agl_trigger(&clli->lli_vfs_inode, sai);
1214 spin_lock(&plli->lli_agl_lock);
1216 spin_unlock(&plli->lli_agl_lock);
1221 * chain is exhausted.
1222 * Normal case: continue to the next page.
1224 ll_release_page(page, le32_to_cpu(dp->ldp_flags) &
1226 sai->sai_in_readpage = 1;
1227 page = ll_get_dir_page(dir, pos, &chain);
1228 sai->sai_in_readpage = 0;
1230 LASSERT(le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
1231 ll_release_page(page, 1);
1233 * go into overflow page.
1239 if (sai->sai_agl_valid) {
1240 spin_lock(&plli->lli_agl_lock);
1241 thread_set_flags(agl_thread, SVC_STOPPING);
1242 spin_unlock(&plli->lli_agl_lock);
1243 wake_up(&agl_thread->t_ctl_waitq);
1245 CDEBUG(D_READA, "stop agl thread: [pid %d]\n",
1247 l_wait_event(agl_thread->t_ctl_waitq,
1248 thread_is_stopped(agl_thread),
1251 /* Set agl_thread flags anyway. */
1252 thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED);
1254 ll_dir_chain_fini(&chain);
1255 spin_lock(&plli->lli_sa_lock);
1256 if (!sa_received_empty(sai)) {
1257 thread_set_flags(thread, SVC_STOPPING);
1258 spin_unlock(&plli->lli_sa_lock);
1260 /* To release the resources held by received entries. */
1261 while (!sa_received_empty(sai))
1262 ll_post_statahead(sai);
1264 spin_lock(&plli->lli_sa_lock);
1266 thread_set_flags(thread, SVC_STOPPED);
1267 spin_unlock(&plli->lli_sa_lock);
1268 wake_up(&sai->sai_waitq);
1269 wake_up(&thread->t_ctl_waitq);
1272 CDEBUG(D_READA, "statahead thread stopped: [pid %d] [parent %.*s]\n",
1273 current_pid(), parent->d_name.len, parent->d_name.name);
1278 * called in ll_file_release().
1280 void ll_stop_statahead(struct inode *dir, void *key)
1282 struct ll_inode_info *lli = ll_i2info(dir);
1284 if (unlikely(key == NULL))
1287 spin_lock(&lli->lli_sa_lock);
1288 if (lli->lli_opendir_key != key || lli->lli_opendir_pid == 0) {
1289 spin_unlock(&lli->lli_sa_lock);
1293 lli->lli_opendir_key = NULL;
1296 struct l_wait_info lwi = { 0 };
1297 struct ptlrpc_thread *thread = &lli->lli_sai->sai_thread;
1299 if (!thread_is_stopped(thread)) {
1300 thread_set_flags(thread, SVC_STOPPING);
1301 spin_unlock(&lli->lli_sa_lock);
1302 wake_up(&thread->t_ctl_waitq);
1304 CDEBUG(D_READA, "stop statahead thread: [pid %d]\n",
1306 l_wait_event(thread->t_ctl_waitq,
1307 thread_is_stopped(thread),
1310 spin_unlock(&lli->lli_sa_lock);
1314 * Put the ref which was held when first statahead_enter.
1315 * It maybe not the last ref for some statahead requests
1318 ll_sai_put(lli->lli_sai);
1320 lli->lli_opendir_pid = 0;
1321 spin_unlock(&lli->lli_sa_lock);
1327 * not first dirent, or is "."
1329 LS_NONE_FIRST_DE = 0,
1331 * the first non-hidden dirent
1335 * the first hidden dirent, that is "."
1340 static int is_first_dirent(struct inode *dir, struct dentry *dentry)
1342 struct ll_dir_chain chain;
1343 struct qstr *target = &dentry->d_name;
1347 int rc = LS_NONE_FIRST_DE;
1349 ll_dir_chain_init(&chain);
1350 page = ll_get_dir_page(dir, pos, &chain);
1353 struct lu_dirpage *dp;
1354 struct lu_dirent *ent;
1357 struct ll_inode_info *lli = ll_i2info(dir);
1360 CERROR("error reading dir "DFID" at "LPU64": "
1361 "[rc %d] [parent %u]\n",
1362 PFID(ll_inode2fid(dir)), pos,
1363 rc, lli->lli_opendir_pid);
1367 dp = page_address(page);
1368 for (ent = lu_dirent_start(dp); ent != NULL;
1369 ent = lu_dirent_next(ent)) {
1374 hash = le64_to_cpu(ent->lde_hash);
1375 /* The ll_get_dir_page() can return any page containing
1376 * the given hash which may be not the start hash. */
1377 if (unlikely(hash < pos))
1380 namelen = le16_to_cpu(ent->lde_namelen);
1381 if (unlikely(namelen == 0))
1383 * skip dummy record.
1387 name = ent->lde_name;
1388 if (name[0] == '.') {
1394 else if (name[1] == '.' && namelen == 2)
1405 if (dot_de && target->name[0] != '.') {
1406 CDEBUG(D_READA, "%.*s skip hidden file %.*s\n",
1407 target->len, target->name,
1412 if (target->len != namelen ||
1413 memcmp(target->name, name, namelen) != 0)
1414 rc = LS_NONE_FIRST_DE;
1418 rc = LS_FIRST_DOT_DE;
1420 ll_release_page(page, 0);
1423 pos = le64_to_cpu(dp->ldp_hash_end);
1424 if (pos == MDS_DIR_END_OFF) {
1426 * End of directory reached.
1428 ll_release_page(page, 0);
1432 * chain is exhausted
1433 * Normal case: continue to the next page.
1435 ll_release_page(page, le32_to_cpu(dp->ldp_flags) &
1437 page = ll_get_dir_page(dir, pos, &chain);
1440 * go into overflow page.
1442 LASSERT(le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
1443 ll_release_page(page, 1);
1448 ll_dir_chain_fini(&chain);
1453 ll_sai_unplug(struct ll_statahead_info *sai, struct ll_sa_entry *entry)
1455 struct ptlrpc_thread *thread = &sai->sai_thread;
1456 struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
1459 if (entry != NULL && entry->se_stat == SA_ENTRY_SUCC)
1464 ll_sa_entry_fini(sai, entry);
1467 sai->sai_consecutive_miss = 0;
1468 sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max);
1470 struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
1473 sai->sai_consecutive_miss++;
1474 if (sa_low_hit(sai) && thread_is_running(thread)) {
1475 atomic_inc(&sbi->ll_sa_wrong);
1476 CDEBUG(D_READA, "Statahead for dir "DFID" hit "
1477 "ratio too low: hit/miss "LPU64"/"LPU64
1478 ", sent/replied "LPU64"/"LPU64", stopping "
1479 "statahead thread: pid %d\n",
1480 PFID(&lli->lli_fid), sai->sai_hit,
1481 sai->sai_miss, sai->sai_sent,
1482 sai->sai_replied, current_pid());
1483 spin_lock(&lli->lli_sa_lock);
1484 if (!thread_is_stopped(thread))
1485 thread_set_flags(thread, SVC_STOPPING);
1486 spin_unlock(&lli->lli_sa_lock);
1490 if (!thread_is_stopped(thread))
1491 wake_up(&thread->t_ctl_waitq);
1495 * Start statahead thread if this is the first dir entry.
1496 * Otherwise if a thread is started already, wait it until it is ahead of me.
1497 * \retval 1 -- find entry with lock in cache, the caller needs to do
1499 * \retval 0 -- find entry in cache, but without lock, the caller needs
1501 * \retval others -- the caller need to process as non-statahead.
1503 int do_statahead_enter(struct inode *dir, struct dentry **dentryp,
1506 struct ll_inode_info *lli = ll_i2info(dir);
1507 struct ll_statahead_info *sai = lli->lli_sai;
1508 struct dentry *parent;
1509 struct ll_sa_entry *entry;
1510 struct ptlrpc_thread *thread;
1511 struct l_wait_info lwi = { 0 };
1513 struct ll_inode_info *plli;
1515 LASSERT(lli->lli_opendir_pid == current_pid());
1518 thread = &sai->sai_thread;
1519 if (unlikely(thread_is_stopped(thread) &&
1520 list_empty(&sai->sai_entries_stated))) {
1521 /* to release resource */
1522 ll_stop_statahead(dir, lli->lli_opendir_key);
1526 if ((*dentryp)->d_name.name[0] == '.') {
1527 if (sai->sai_ls_all ||
1528 sai->sai_miss_hidden >= sai->sai_skip_hidden) {
1530 * Hidden dentry is the first one, or statahead
1531 * thread does not skip so many hidden dentries
1532 * before "sai_ls_all" enabled as below.
1535 if (!sai->sai_ls_all)
1537 * It maybe because hidden dentry is not
1538 * the first one, "sai_ls_all" was not
1539 * set, then "ls -al" missed. Enable
1540 * "sai_ls_all" for such case.
1542 sai->sai_ls_all = 1;
1545 * Such "getattr" has been skipped before
1546 * "sai_ls_all" enabled as above.
1548 sai->sai_miss_hidden++;
1553 entry = ll_sa_entry_get_byname(sai, &(*dentryp)->d_name);
1554 if (entry == NULL || only_unplug) {
1555 ll_sai_unplug(sai, entry);
1556 return entry ? 1 : -EAGAIN;
1559 /* if statahead is busy in readdir, help it do post-work */
1560 while (!ll_sa_entry_stated(entry) &&
1561 sai->sai_in_readpage &&
1562 !sa_received_empty(sai))
1563 ll_post_statahead(sai);
1565 if (!ll_sa_entry_stated(entry)) {
1566 sai->sai_index_wait = entry->se_index;
1567 lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
1568 LWI_ON_SIGNAL_NOOP, NULL);
1569 rc = l_wait_event(sai->sai_waitq,
1570 ll_sa_entry_stated(entry) ||
1571 thread_is_stopped(thread),
1574 ll_sai_unplug(sai, entry);
1579 if (entry->se_stat == SA_ENTRY_SUCC &&
1580 entry->se_inode != NULL) {
1581 struct inode *inode = entry->se_inode;
1582 struct lookup_intent it = { .it_op = IT_GETATTR,
1583 .d.lustre.it_lock_handle =
1587 rc = md_revalidate_lock(ll_i2mdexp(dir), &it,
1588 ll_inode2fid(inode), &bits);
1590 if ((*dentryp)->d_inode == NULL) {
1591 *dentryp = ll_splice_alias(inode,
1593 } else if ((*dentryp)->d_inode != inode) {
1594 /* revalidate, but inode is recreated */
1596 "stale dentry %.*s inode %lu/%u, "
1597 "statahead inode %lu/%u\n",
1598 (*dentryp)->d_name.len,
1599 (*dentryp)->d_name.name,
1600 (*dentryp)->d_inode->i_ino,
1601 (*dentryp)->d_inode->i_generation,
1603 inode->i_generation);
1604 ll_sai_unplug(sai, entry);
1609 entry->se_inode = NULL;
1611 if ((bits & MDS_INODELOCK_LOOKUP) &&
1612 d_lustre_invalid(*dentryp))
1613 d_lustre_revalidate(*dentryp);
1614 ll_intent_release(&it);
1618 ll_sai_unplug(sai, entry);
1622 /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
1623 rc = is_first_dirent(dir, *dentryp);
1624 if (rc == LS_NONE_FIRST_DE)
1625 /* It is not "ls -{a}l" operation, no need statahead for it. */
1626 GOTO(out, rc = -EAGAIN);
1628 sai = ll_sai_alloc();
1630 GOTO(out, rc = -ENOMEM);
1632 sai->sai_ls_all = (rc == LS_FIRST_DOT_DE);
1633 sai->sai_inode = igrab(dir);
1634 if (unlikely(sai->sai_inode == NULL)) {
1635 CWARN("Do not start stat ahead on dying inode "DFID"\n",
1636 PFID(&lli->lli_fid));
1637 GOTO(out, rc = -ESTALE);
1640 /* get parent reference count here, and put it in ll_statahead_thread */
1641 parent = dget((*dentryp)->d_parent);
1642 if (unlikely(sai->sai_inode != parent->d_inode)) {
1643 struct ll_inode_info *nlli = ll_i2info(parent->d_inode);
1645 CWARN("Race condition, someone changed %.*s just now: "
1646 "old parent "DFID", new parent "DFID"\n",
1647 (*dentryp)->d_name.len, (*dentryp)->d_name.name,
1648 PFID(&lli->lli_fid), PFID(&nlli->lli_fid));
1650 iput(sai->sai_inode);
1651 GOTO(out, rc = -EAGAIN);
1654 CDEBUG(D_READA, "start statahead thread: [pid %d] [parent %.*s]\n",
1655 current_pid(), parent->d_name.len, parent->d_name.name);
1659 plli = ll_i2info(parent->d_inode);
1660 rc = PTR_ERR(kthread_run(ll_statahead_thread, parent,
1661 "ll_sa_%u", plli->lli_opendir_pid));
1662 thread = &sai->sai_thread;
1663 if (IS_ERR_VALUE(rc)) {
1664 CERROR("can't start ll_sa thread, rc: %d\n", rc);
1666 lli->lli_opendir_key = NULL;
1667 thread_set_flags(thread, SVC_STOPPED);
1668 thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED);
1670 LASSERT(lli->lli_sai == NULL);
1674 l_wait_event(thread->t_ctl_waitq,
1675 thread_is_running(thread) || thread_is_stopped(thread),
1679 * We don't stat-ahead for the first dirent since we are already in
1687 spin_lock(&lli->lli_sa_lock);
1688 lli->lli_opendir_key = NULL;
1689 lli->lli_opendir_pid = 0;
1690 spin_unlock(&lli->lli_sa_lock);