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, 2015, 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>
39 #include <linux/kthread.h>
41 #include <linux/highmem.h>
42 #include <linux/pagemap.h>
44 #define DEBUG_SUBSYSTEM S_LLITE
46 #include <obd_support.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 */
59 /* sa_entry is not refcounted: statahead thread allocates it and do async stat,
60 * and in async stat callback ll_statahead_interpret() will add it into
61 * sai_interim_entries, later statahead thread will call sa_handle_callback() to
62 * instantiate entry and move it into sai_entries, and then only scanner process
63 * can access and free it. */
65 /* link into sai_interim_entries or sai_entries */
66 struct list_head se_list;
67 /* link into sai hash table locally */
68 struct list_head se_hash;
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;
89 static unsigned int sai_generation = 0;
90 static DEFINE_SPINLOCK(sai_generation_lock);
92 static inline int sa_unhashed(struct sa_entry *entry)
94 return list_empty(&entry->se_hash);
97 /* sa_entry is ready to use */
98 static inline int sa_ready(struct sa_entry *entry)
101 return (entry->se_state != SA_ENTRY_INIT);
104 /* hash value to put in sai_cache */
105 static inline int sa_hash(int val)
107 return val & LL_SA_CACHE_MASK;
110 /* hash entry into sai_cache */
112 sa_rehash(struct ll_statahead_info *sai, struct sa_entry *entry)
114 int i = sa_hash(entry->se_qstr.hash);
116 spin_lock(&sai->sai_cache_lock[i]);
117 list_add_tail(&entry->se_hash, &sai->sai_cache[i]);
118 spin_unlock(&sai->sai_cache_lock[i]);
121 /* unhash entry from sai_cache */
123 sa_unhash(struct ll_statahead_info *sai, struct sa_entry *entry)
125 int i = sa_hash(entry->se_qstr.hash);
127 spin_lock(&sai->sai_cache_lock[i]);
128 list_del_init(&entry->se_hash);
129 spin_unlock(&sai->sai_cache_lock[i]);
132 static inline int agl_should_run(struct ll_statahead_info *sai,
135 return (inode != NULL && S_ISREG(inode->i_mode) && sai->sai_agl_valid);
138 static inline struct ll_inode_info *
139 agl_first_entry(struct ll_statahead_info *sai)
141 return list_entry(sai->sai_agls.next, struct ll_inode_info,
145 /* statahead window is full */
146 static inline int sa_sent_full(struct ll_statahead_info *sai)
148 return atomic_read(&sai->sai_cache_count) >= sai->sai_max;
151 /* got async stat replies */
152 static inline int sa_has_callback(struct ll_statahead_info *sai)
154 return !list_empty(&sai->sai_interim_entries);
157 static inline int agl_list_empty(struct ll_statahead_info *sai)
159 return list_empty(&sai->sai_agls);
163 * (1) hit ratio less than 80%
165 * (2) consecutive miss more than 8
166 * then means low hit.
168 static inline int sa_low_hit(struct ll_statahead_info *sai)
170 return ((sai->sai_hit > 7 && sai->sai_hit < 4 * sai->sai_miss) ||
171 (sai->sai_consecutive_miss > 8));
175 * if the given index is behind of statahead window more than
176 * SA_OMITTED_ENTRY_MAX, then it is old.
178 static inline int is_omitted_entry(struct ll_statahead_info *sai, __u64 index)
180 return ((__u64)sai->sai_max + index + SA_OMITTED_ENTRY_MAX <
184 /* allocate sa_entry and hash it to allow scanner process to find it */
185 static struct sa_entry *
186 sa_alloc(struct ll_statahead_info *sai, __u64 index, const char *name, int len,
187 const struct lu_fid *fid)
189 struct ll_inode_info *lli;
190 struct sa_entry *entry;
195 entry_size = sizeof(struct sa_entry) + (len & ~3) + 4;
196 OBD_ALLOC(entry, entry_size);
197 if (unlikely(entry == NULL))
198 RETURN(ERR_PTR(-ENOMEM));
200 CDEBUG(D_READA, "alloc sa entry %.*s(%p) index "LPU64"\n",
201 len, name, entry, index);
203 entry->se_index = index;
205 entry->se_state = SA_ENTRY_INIT;
206 entry->se_size = entry_size;
207 dname = (char *)entry + sizeof(struct sa_entry);
208 memcpy(dname, name, len);
210 entry->se_qstr.hash = full_name_hash(name, len);
211 entry->se_qstr.len = len;
212 entry->se_qstr.name = dname;
213 entry->se_fid = *fid;
215 lli = ll_i2info(sai->sai_dentry->d_inode);
217 spin_lock(&lli->lli_sa_lock);
218 INIT_LIST_HEAD(&entry->se_list);
219 sa_rehash(sai, entry);
220 spin_unlock(&lli->lli_sa_lock);
222 atomic_inc(&sai->sai_cache_count);
227 /* free sa_entry, which should have been unhashed and not in any list */
228 static void sa_free(struct ll_statahead_info *sai, struct sa_entry *entry)
230 CDEBUG(D_READA, "free sa entry %.*s(%p) index "LPU64"\n",
231 entry->se_qstr.len, entry->se_qstr.name, entry,
234 LASSERT(list_empty(&entry->se_list));
235 LASSERT(sa_unhashed(entry));
237 OBD_FREE(entry, entry->se_size);
238 atomic_dec(&sai->sai_cache_count);
242 * find sa_entry by name, used by directory scanner, lock is not needed because
243 * only scanner can remove the entry from cache.
245 static struct sa_entry *
246 sa_get(struct ll_statahead_info *sai, const struct qstr *qstr)
248 struct sa_entry *entry;
249 int i = sa_hash(qstr->hash);
251 list_for_each_entry(entry, &sai->sai_cache[i], se_hash) {
252 if (entry->se_qstr.hash == qstr->hash &&
253 entry->se_qstr.len == qstr->len &&
254 memcmp(entry->se_qstr.name, qstr->name, qstr->len) == 0)
260 /* unhash and unlink sa_entry, and then free it */
262 sa_kill(struct ll_statahead_info *sai, struct sa_entry *entry)
264 struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
266 LASSERT(!sa_unhashed(entry));
267 LASSERT(!list_empty(&entry->se_list));
268 LASSERT(sa_ready(entry));
270 sa_unhash(sai, entry);
272 spin_lock(&lli->lli_sa_lock);
273 list_del_init(&entry->se_list);
274 spin_unlock(&lli->lli_sa_lock);
276 if (entry->se_inode != NULL)
277 iput(entry->se_inode);
282 /* called by scanner after use, sa_entry will be killed */
284 sa_put(struct ll_statahead_info *sai, struct sa_entry *entry)
286 struct sa_entry *tmp, *next;
288 if (entry != NULL && entry->se_state == SA_ENTRY_SUCC) {
289 struct ll_sb_info *sbi = ll_i2sbi(sai->sai_dentry->d_inode);
292 sai->sai_consecutive_miss = 0;
293 sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max);
296 sai->sai_consecutive_miss++;
302 /* kill old completed entries, only scanner process does this, no need
304 list_for_each_entry_safe(tmp, next, &sai->sai_entries, se_list) {
305 if (!is_omitted_entry(sai, tmp->se_index))
310 wake_up(&sai->sai_thread.t_ctl_waitq);
313 /* update state and sort add entry to sai_entries by index, return true if
314 * scanner is waiting on this entry. */
316 __sa_make_ready(struct ll_statahead_info *sai, struct sa_entry *entry, int ret)
319 struct list_head *pos = &sai->sai_entries;
320 __u64 index = entry->se_index;
322 LASSERT(!sa_ready(entry));
323 LASSERT(list_empty(&entry->se_list));
325 list_for_each_entry_reverse(se, &sai->sai_entries, se_list) {
326 if (se->se_index < entry->se_index) {
331 list_add(&entry->se_list, pos);
332 entry->se_state = ret < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC;
334 return (index == sai->sai_index_wait);
338 * release resources used in async stat RPC, update entry state and wakeup if
339 * scanner process it waiting on this entry.
342 sa_make_ready(struct ll_statahead_info *sai, struct sa_entry *entry, int ret)
344 struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
345 struct md_enqueue_info *minfo = entry->se_minfo;
346 struct ptlrpc_request *req = entry->se_req;
349 /* release resources used in RPC */
351 entry->se_minfo = NULL;
352 ll_intent_release(&minfo->mi_it);
358 entry->se_req = NULL;
359 ptlrpc_req_finished(req);
362 spin_lock(&lli->lli_sa_lock);
363 wakeup = __sa_make_ready(sai, entry, ret);
364 spin_unlock(&lli->lli_sa_lock);
367 wake_up(&sai->sai_waitq);
370 /* insert inode into the list of sai_agls */
371 static void ll_agl_add(struct ll_statahead_info *sai,
372 struct inode *inode, int index)
374 struct ll_inode_info *child = ll_i2info(inode);
375 struct ll_inode_info *parent = ll_i2info(sai->sai_dentry->d_inode);
378 spin_lock(&child->lli_agl_lock);
379 if (child->lli_agl_index == 0) {
380 child->lli_agl_index = index;
381 spin_unlock(&child->lli_agl_lock);
383 LASSERT(list_empty(&child->lli_agl_list));
386 spin_lock(&parent->lli_agl_lock);
387 if (agl_list_empty(sai))
389 list_add_tail(&child->lli_agl_list, &sai->sai_agls);
390 spin_unlock(&parent->lli_agl_lock);
392 spin_unlock(&child->lli_agl_lock);
396 wake_up(&sai->sai_agl_thread.t_ctl_waitq);
400 static struct ll_statahead_info *ll_sai_alloc(struct dentry *dentry)
402 struct ll_statahead_info *sai;
403 struct ll_inode_info *lli = ll_i2info(dentry->d_inode);
411 sai->sai_dentry = dget(dentry);
412 atomic_set(&sai->sai_refcount, 1);
413 sai->sai_max = LL_SA_RPC_MIN;
415 init_waitqueue_head(&sai->sai_waitq);
416 init_waitqueue_head(&sai->sai_thread.t_ctl_waitq);
417 init_waitqueue_head(&sai->sai_agl_thread.t_ctl_waitq);
419 INIT_LIST_HEAD(&sai->sai_interim_entries);
420 INIT_LIST_HEAD(&sai->sai_entries);
421 INIT_LIST_HEAD(&sai->sai_agls);
423 for (i = 0; i < LL_SA_CACHE_SIZE; i++) {
424 INIT_LIST_HEAD(&sai->sai_cache[i]);
425 spin_lock_init(&sai->sai_cache_lock[i]);
427 atomic_set(&sai->sai_cache_count, 0);
429 spin_lock(&sai_generation_lock);
430 lli->lli_sa_generation = ++sai_generation;
431 if (unlikely(sai_generation == 0))
432 lli->lli_sa_generation = ++sai_generation;
433 spin_unlock(&sai_generation_lock);
439 static inline void ll_sai_free(struct ll_statahead_info *sai)
441 LASSERT(sai->sai_dentry != NULL);
442 dput(sai->sai_dentry);
447 * take refcount of sai if sai for @dir exists, which means statahead is on for
450 static inline struct ll_statahead_info *ll_sai_get(struct inode *dir)
452 struct ll_inode_info *lli = ll_i2info(dir);
453 struct ll_statahead_info *sai = NULL;
455 spin_lock(&lli->lli_sa_lock);
458 atomic_inc(&sai->sai_refcount);
459 spin_unlock(&lli->lli_sa_lock);
465 * put sai refcount after use, if refcount reaches zero, free sai and sa_entries
468 static void ll_sai_put(struct ll_statahead_info *sai)
470 struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
472 if (atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_sa_lock)) {
473 struct sa_entry *entry, *next;
474 struct ll_sb_info *sbi = ll_i2sbi(sai->sai_dentry->d_inode);
477 spin_unlock(&lli->lli_sa_lock);
479 LASSERT(thread_is_stopped(&sai->sai_thread));
480 LASSERT(thread_is_stopped(&sai->sai_agl_thread));
481 LASSERT(sai->sai_sent == sai->sai_replied);
482 LASSERT(!sa_has_callback(sai));
484 list_for_each_entry_safe(entry, next, &sai->sai_entries,
488 LASSERT(atomic_read(&sai->sai_cache_count) == 0);
489 LASSERT(agl_list_empty(sai));
492 atomic_dec(&sbi->ll_sa_running);
496 /* Do NOT forget to drop inode refcount when into sai_agls. */
497 static void ll_agl_trigger(struct inode *inode, struct ll_statahead_info *sai)
499 struct ll_inode_info *lli = ll_i2info(inode);
500 __u64 index = lli->lli_agl_index;
504 LASSERT(list_empty(&lli->lli_agl_list));
506 /* AGL maybe fall behind statahead with one entry */
507 if (is_omitted_entry(sai, index + 1)) {
508 lli->lli_agl_index = 0;
513 /* Someone is in glimpse (sync or async), do nothing. */
514 rc = down_write_trylock(&lli->lli_glimpse_sem);
516 lli->lli_agl_index = 0;
522 * Someone triggered glimpse within 1 sec before.
523 * 1) The former glimpse succeeded with glimpse lock granted by OST, and
524 * if the lock is still cached on client, AGL needs to do nothing. If
525 * it is cancelled by other client, AGL maybe cannot obtaion new lock
526 * for no glimpse callback triggered by AGL.
527 * 2) The former glimpse succeeded, but OST did not grant glimpse lock.
528 * Under such case, it is quite possible that the OST will not grant
529 * glimpse lock for AGL also.
530 * 3) The former glimpse failed, compared with other two cases, it is
531 * relative rare. AGL can ignore such case, and it will not muchly
532 * affect the performance.
534 if (lli->lli_glimpse_time != 0 &&
535 cfs_time_before(cfs_time_shift(-1), lli->lli_glimpse_time)) {
536 up_write(&lli->lli_glimpse_sem);
537 lli->lli_agl_index = 0;
542 CDEBUG(D_READA, "Handling (init) async glimpse: inode = "
543 DFID", idx = "LPU64"\n", PFID(&lli->lli_fid), index);
546 lli->lli_agl_index = 0;
547 lli->lli_glimpse_time = cfs_time_current();
548 up_write(&lli->lli_glimpse_sem);
550 CDEBUG(D_READA, "Handled (init) async glimpse: inode= "
551 DFID", idx = "LPU64", rc = %d\n",
552 PFID(&lli->lli_fid), index, rc);
560 * prepare inode for sa entry, add it into agl list, now sa_entry is ready
561 * to be used by scanner process.
563 static void sa_instantiate(struct ll_statahead_info *sai,
564 struct sa_entry *entry)
566 struct inode *dir = sai->sai_dentry->d_inode;
568 struct md_enqueue_info *minfo;
569 struct lookup_intent *it;
570 struct ptlrpc_request *req;
571 struct mdt_body *body;
575 LASSERT(entry->se_handle != 0);
577 minfo = entry->se_minfo;
580 body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
582 GOTO(out, rc = -EFAULT);
584 child = entry->se_inode;
586 /* revalidate; unlinked and re-created with the same name */
587 if (unlikely(!lu_fid_eq(&minfo->mi_data.op_fid2,
589 entry->se_inode = NULL;
595 it->it_lock_handle = entry->se_handle;
596 rc = md_revalidate_lock(ll_i2mdexp(dir), it, ll_inode2fid(dir), NULL);
598 GOTO(out, rc = -EAGAIN);
600 rc = ll_prep_inode(&child, req, dir->i_sb, it);
604 CDEBUG(D_READA, "%s: setting %.*s"DFID" l_data to inode %p\n",
605 ll_get_fsname(child->i_sb, NULL, 0),
606 entry->se_qstr.len, entry->se_qstr.name,
607 PFID(ll_inode2fid(child)), child);
608 ll_set_lock_data(ll_i2sbi(dir)->ll_md_exp, child, it, NULL);
610 entry->se_inode = child;
612 if (agl_should_run(sai, child))
613 ll_agl_add(sai, child, entry->se_index);
618 /* sa_make_ready() will drop ldlm ibits lock refcount by calling
619 * ll_intent_drop_lock() in spite of failures. Do not worry about
620 * calling ll_intent_drop_lock() more than once. */
621 sa_make_ready(sai, entry, rc);
624 /* once there are async stat replies, instantiate sa_entry from replies */
625 static void sa_handle_callback(struct ll_statahead_info *sai)
627 struct ll_inode_info *lli;
629 lli = ll_i2info(sai->sai_dentry->d_inode);
631 while (sa_has_callback(sai)) {
632 struct sa_entry *entry;
634 spin_lock(&lli->lli_sa_lock);
635 if (unlikely(!sa_has_callback(sai))) {
636 spin_unlock(&lli->lli_sa_lock);
639 entry = list_entry(sai->sai_interim_entries.next,
640 struct sa_entry, se_list);
641 list_del_init(&entry->se_list);
642 spin_unlock(&lli->lli_sa_lock);
644 sa_instantiate(sai, entry);
649 * callback for async stat RPC, because this is called in ptlrpcd context, we
650 * only put sa_entry in sai_interim_entries, and wake up statahead thread to
651 * really prepare inode and instantiate sa_entry later.
653 static int ll_statahead_interpret(struct ptlrpc_request *req,
654 struct md_enqueue_info *minfo, int rc)
656 struct lookup_intent *it = &minfo->mi_it;
657 struct inode *dir = minfo->mi_dir;
658 struct ll_inode_info *lli = ll_i2info(dir);
659 struct ll_statahead_info *sai = lli->lli_sai;
660 struct sa_entry *entry = (struct sa_entry *)minfo->mi_cbdata;
662 wait_queue_head_t *waitq = NULL;
665 if (it_disposition(it, DISP_LOOKUP_NEG))
668 /* because statahead thread will wait for all inflight RPC to finish,
669 * sai should be always valid, no need to refcount */
670 LASSERT(sai != NULL);
671 LASSERT(!thread_is_stopped(&sai->sai_thread));
672 LASSERT(entry != NULL);
674 CDEBUG(D_READA, "sa_entry %.*s rc %d\n",
675 entry->se_qstr.len, entry->se_qstr.name, rc);
678 ll_intent_release(it);
682 /* release ibits lock ASAP to avoid deadlock when statahead
683 * thread enqueues lock on parent in readdir and another
684 * process enqueues lock on child with parent lock held, eg.
686 handle = it->it_lock_handle;
687 ll_intent_drop_lock(it);
690 spin_lock(&lli->lli_sa_lock);
692 if (__sa_make_ready(sai, entry, rc))
693 waitq = &sai->sai_waitq;
695 entry->se_minfo = minfo;
696 entry->se_req = ptlrpc_request_addref(req);
697 /* Release the async ibits lock ASAP to avoid deadlock
698 * when statahead thread tries to enqueue lock on parent
699 * for readpage and other tries to enqueue lock on child
700 * with parent's lock held, for example: unlink. */
701 entry->se_handle = handle;
702 if (!sa_has_callback(sai))
703 waitq = &sai->sai_thread.t_ctl_waitq;
705 list_add_tail(&entry->se_list, &sai->sai_interim_entries);
710 spin_unlock(&lli->lli_sa_lock);
715 /* finish async stat RPC arguments */
716 static void sa_fini_data(struct md_enqueue_info *minfo)
723 * prepare arguments for async stat RPC.
725 static struct md_enqueue_info *
726 sa_prep_data(struct inode *dir, struct inode *child, struct sa_entry *entry)
728 struct md_enqueue_info *minfo;
729 struct ldlm_enqueue_info *einfo;
730 struct md_op_data *op_data;
732 OBD_ALLOC_PTR(minfo);
734 return ERR_PTR(-ENOMEM);
736 op_data = ll_prep_md_op_data(&minfo->mi_data, dir, child, NULL, 0, 0,
737 LUSTRE_OPC_ANY, NULL);
738 if (IS_ERR(op_data)) {
740 return (struct md_enqueue_info *)op_data;
744 op_data->op_fid2 = entry->se_fid;
746 minfo->mi_it.it_op = IT_GETATTR;
747 minfo->mi_dir = igrab(dir);
748 minfo->mi_cb = ll_statahead_interpret;
749 minfo->mi_cbdata = entry;
751 einfo = &minfo->mi_einfo;
752 einfo->ei_type = LDLM_IBITS;
753 einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
754 einfo->ei_cb_bl = ll_md_blocking_ast;
755 einfo->ei_cb_cp = ldlm_completion_ast;
756 einfo->ei_cb_gl = NULL;
757 einfo->ei_cbdata = NULL;
762 /* async stat for file not found in dcache */
763 static int sa_lookup(struct inode *dir, struct sa_entry *entry)
765 struct md_enqueue_info *minfo;
769 minfo = sa_prep_data(dir, NULL, entry);
771 RETURN(PTR_ERR(minfo));
773 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo);
781 * async stat for file found in dcache, similar to .revalidate
783 * \retval 1 dentry valid, no RPC sent
784 * \retval 0 dentry invalid, will send async stat RPC
785 * \retval negative number upon error
787 static int sa_revalidate(struct inode *dir, struct sa_entry *entry,
788 struct dentry *dentry)
790 struct inode *inode = dentry->d_inode;
791 struct lookup_intent it = { .it_op = IT_GETATTR,
792 .it_lock_handle = 0 };
793 struct md_enqueue_info *minfo;
797 if (unlikely(inode == NULL))
800 if (d_mountpoint(dentry))
803 entry->se_inode = igrab(inode);
804 rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode),
807 entry->se_handle = it.it_lock_handle;
808 ll_intent_release(&it);
812 minfo = sa_prep_data(dir, inode, entry);
814 entry->se_inode = NULL;
816 RETURN(PTR_ERR(minfo));
819 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo);
821 entry->se_inode = NULL;
829 /* async stat for file with @name */
830 static void sa_statahead(struct dentry *parent, const char *name, int len,
831 const struct lu_fid *fid)
833 struct inode *dir = parent->d_inode;
834 struct ll_inode_info *lli = ll_i2info(dir);
835 struct ll_statahead_info *sai = lli->lli_sai;
836 struct dentry *dentry = NULL;
837 struct sa_entry *entry;
841 entry = sa_alloc(sai, sai->sai_index, name, len, fid);
845 dentry = d_lookup(parent, &entry->se_qstr);
847 rc = sa_lookup(dir, entry);
849 rc = sa_revalidate(dir, entry, dentry);
850 if (rc == 1 && agl_should_run(sai, dentry->d_inode))
851 ll_agl_add(sai, dentry->d_inode, entry->se_index);
858 sa_make_ready(sai, entry, rc);
867 /* async glimpse (agl) thread main function */
868 static int ll_agl_thread(void *arg)
870 struct dentry *parent = (struct dentry *)arg;
871 struct inode *dir = parent->d_inode;
872 struct ll_inode_info *plli = ll_i2info(dir);
873 struct ll_inode_info *clli;
874 struct ll_sb_info *sbi = ll_i2sbi(dir);
875 struct ll_statahead_info *sai;
876 struct ptlrpc_thread *thread;
877 struct l_wait_info lwi = { 0 };
881 sai = ll_sai_get(dir);
882 thread = &sai->sai_agl_thread;
883 thread->t_pid = current_pid();
884 CDEBUG(D_READA, "agl thread started: sai %p, parent %.*s\n",
885 sai, parent->d_name.len, parent->d_name.name);
887 atomic_inc(&sbi->ll_agl_total);
888 spin_lock(&plli->lli_agl_lock);
889 sai->sai_agl_valid = 1;
890 if (thread_is_init(thread))
891 /* If someone else has changed the thread state
892 * (e.g. already changed to SVC_STOPPING), we can't just
893 * blindly overwrite that setting. */
894 thread_set_flags(thread, SVC_RUNNING);
895 spin_unlock(&plli->lli_agl_lock);
896 wake_up(&thread->t_ctl_waitq);
899 l_wait_event(thread->t_ctl_waitq,
900 !agl_list_empty(sai) ||
901 !thread_is_running(thread),
904 if (!thread_is_running(thread))
907 spin_lock(&plli->lli_agl_lock);
908 /* The statahead thread maybe help to process AGL entries,
909 * so check whether list empty again. */
910 if (!agl_list_empty(sai)) {
911 clli = agl_first_entry(sai);
912 list_del_init(&clli->lli_agl_list);
913 spin_unlock(&plli->lli_agl_lock);
914 ll_agl_trigger(&clli->lli_vfs_inode, sai);
916 spin_unlock(&plli->lli_agl_lock);
920 spin_lock(&plli->lli_agl_lock);
921 sai->sai_agl_valid = 0;
922 while (!agl_list_empty(sai)) {
923 clli = agl_first_entry(sai);
924 list_del_init(&clli->lli_agl_list);
925 spin_unlock(&plli->lli_agl_lock);
926 clli->lli_agl_index = 0;
927 iput(&clli->lli_vfs_inode);
928 spin_lock(&plli->lli_agl_lock);
930 thread_set_flags(thread, SVC_STOPPED);
931 spin_unlock(&plli->lli_agl_lock);
932 wake_up(&thread->t_ctl_waitq);
934 CDEBUG(D_READA, "agl thread stopped: sai %p, parent %.*s\n",
935 sai, parent->d_name.len, parent->d_name.name);
939 /* start agl thread */
940 static void ll_start_agl(struct dentry *parent, struct ll_statahead_info *sai)
942 struct ptlrpc_thread *thread = &sai->sai_agl_thread;
943 struct l_wait_info lwi = { 0 };
944 struct ll_inode_info *plli;
945 struct task_struct *task;
948 CDEBUG(D_READA, "start agl thread: sai %p, parent %.*s\n",
949 sai, parent->d_name.len, parent->d_name.name);
951 plli = ll_i2info(parent->d_inode);
952 task = kthread_run(ll_agl_thread, parent,
953 "ll_agl_%u", plli->lli_opendir_pid);
955 CERROR("can't start ll_agl thread, rc: %ld\n", PTR_ERR(task));
956 thread_set_flags(thread, SVC_STOPPED);
960 l_wait_event(thread->t_ctl_waitq,
961 thread_is_running(thread) || thread_is_stopped(thread),
966 /* statahead thread main function */
967 static int ll_statahead_thread(void *arg)
969 struct dentry *parent = (struct dentry *)arg;
970 struct inode *dir = parent->d_inode;
971 struct ll_inode_info *lli = ll_i2info(dir);
972 struct ll_sb_info *sbi = ll_i2sbi(dir);
973 struct ll_statahead_info *sai;
974 struct ptlrpc_thread *sa_thread;
975 struct ptlrpc_thread *agl_thread;
977 struct md_op_data *op_data;
978 struct ll_dir_chain chain;
979 struct l_wait_info lwi = { 0 };
980 struct page *page = NULL;
985 sai = ll_sai_get(dir);
986 sa_thread = &sai->sai_thread;
987 agl_thread = &sai->sai_agl_thread;
988 sa_thread->t_pid = current_pid();
989 CDEBUG(D_READA, "statahead thread starting: sai %p, parent %.*s\n",
990 sai, parent->d_name.len, parent->d_name.name);
992 op_data = ll_prep_md_op_data(NULL, dir, dir, NULL, 0, 0,
993 LUSTRE_OPC_ANY, dir);
995 GOTO(out, rc = PTR_ERR(op_data));
997 op_data->op_max_pages = ll_i2sbi(dir)->ll_md_brw_pages;
999 if (sbi->ll_flags & LL_SBI_AGL_ENABLED)
1000 ll_start_agl(parent, sai);
1002 atomic_inc(&sbi->ll_sa_total);
1003 spin_lock(&lli->lli_sa_lock);
1004 if (thread_is_init(sa_thread))
1005 /* If someone else has changed the thread state
1006 * (e.g. already changed to SVC_STOPPING), we can't just
1007 * blindly overwrite that setting. */
1008 thread_set_flags(sa_thread, SVC_RUNNING);
1009 spin_unlock(&lli->lli_sa_lock);
1010 wake_up(&sa_thread->t_ctl_waitq);
1012 ll_dir_chain_init(&chain);
1013 while (pos != MDS_DIR_END_OFF && thread_is_running(sa_thread)) {
1014 struct lu_dirpage *dp;
1015 struct lu_dirent *ent;
1017 sai->sai_in_readpage = 1;
1018 page = ll_get_dir_page(dir, op_data, pos, &chain);
1019 sai->sai_in_readpage = 0;
1022 CDEBUG(D_READA, "error reading dir "DFID" at "LPU64
1023 "/"LPU64" opendir_pid = %u: rc = %d\n",
1024 PFID(ll_inode2fid(dir)), pos, sai->sai_index,
1025 lli->lli_opendir_pid, rc);
1029 dp = page_address(page);
1030 for (ent = lu_dirent_start(dp);
1031 ent != NULL && thread_is_running(sa_thread) &&
1033 ent = lu_dirent_next(ent)) {
1039 hash = le64_to_cpu(ent->lde_hash);
1040 if (unlikely(hash < pos))
1042 * Skip until we find target hash value.
1046 namelen = le16_to_cpu(ent->lde_namelen);
1047 if (unlikely(namelen == 0))
1049 * Skip dummy record.
1053 name = ent->lde_name;
1054 if (name[0] == '.') {
1060 } else if (name[1] == '.' && namelen == 2) {
1065 } else if (!sai->sai_ls_all) {
1067 * skip hidden files.
1069 sai->sai_skip_hidden++;
1075 * don't stat-ahead first entry.
1077 if (unlikely(++first == 1))
1080 fid_le_to_cpu(&fid, &ent->lde_fid);
1082 /* wait for spare statahead window */
1084 l_wait_event(sa_thread->t_ctl_waitq,
1085 !sa_sent_full(sai) ||
1086 sa_has_callback(sai) ||
1087 !agl_list_empty(sai) ||
1088 !thread_is_running(sa_thread),
1091 sa_handle_callback(sai);
1093 spin_lock(&lli->lli_agl_lock);
1094 while (sa_sent_full(sai) &&
1095 !agl_list_empty(sai)) {
1096 struct ll_inode_info *clli;
1098 clli = agl_first_entry(sai);
1099 list_del_init(&clli->lli_agl_list);
1100 spin_unlock(&lli->lli_agl_lock);
1102 ll_agl_trigger(&clli->lli_vfs_inode,
1105 spin_lock(&lli->lli_agl_lock);
1107 spin_unlock(&lli->lli_agl_lock);
1108 } while (sa_sent_full(sai) &&
1109 thread_is_running(sa_thread));
1111 sa_statahead(parent, name, namelen, &fid);
1114 pos = le64_to_cpu(dp->ldp_hash_end);
1115 ll_release_page(dir, page,
1116 le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
1118 if (sa_low_hit(sai)) {
1120 atomic_inc(&sbi->ll_sa_wrong);
1121 CDEBUG(D_READA, "Statahead for dir "DFID" hit "
1122 "ratio too low: hit/miss "LPU64"/"LPU64
1123 ", sent/replied "LPU64"/"LPU64", stopping "
1124 "statahead thread: pid %d\n",
1125 PFID(&lli->lli_fid), sai->sai_hit,
1126 sai->sai_miss, sai->sai_sent,
1127 sai->sai_replied, current_pid());
1131 ll_dir_chain_fini(&chain);
1132 ll_finish_md_op_data(op_data);
1135 spin_lock(&lli->lli_sa_lock);
1136 thread_set_flags(sa_thread, SVC_STOPPING);
1137 lli->lli_sa_enabled = 0;
1138 spin_unlock(&lli->lli_sa_lock);
1141 /* statahead is finished, but statahead entries need to be cached, wait
1142 * for file release to stop me. */
1143 while (thread_is_running(sa_thread)) {
1144 l_wait_event(sa_thread->t_ctl_waitq,
1145 sa_has_callback(sai) ||
1146 !thread_is_running(sa_thread),
1149 sa_handle_callback(sai);
1154 if (sai->sai_agl_valid) {
1155 spin_lock(&lli->lli_agl_lock);
1156 thread_set_flags(agl_thread, SVC_STOPPING);
1157 spin_unlock(&lli->lli_agl_lock);
1158 wake_up(&agl_thread->t_ctl_waitq);
1160 CDEBUG(D_READA, "stop agl thread: sai %p pid %u\n",
1161 sai, (unsigned int)agl_thread->t_pid);
1162 l_wait_event(agl_thread->t_ctl_waitq,
1163 thread_is_stopped(agl_thread),
1166 /* Set agl_thread flags anyway. */
1167 thread_set_flags(agl_thread, SVC_STOPPED);
1170 /* wait for inflight statahead RPCs to finish, and then we can free sai
1171 * safely because statahead RPC will access sai data */
1172 while (sai->sai_sent != sai->sai_replied) {
1173 /* in case we're not woken up, timeout wait */
1174 lwi = LWI_TIMEOUT(msecs_to_jiffies(MSEC_PER_SEC >> 3),
1176 l_wait_event(sa_thread->t_ctl_waitq,
1177 sai->sai_sent == sai->sai_replied, &lwi);
1180 /* release resources held by statahead RPCs */
1181 sa_handle_callback(sai);
1183 spin_lock(&lli->lli_sa_lock);
1184 thread_set_flags(sa_thread, SVC_STOPPED);
1185 spin_unlock(&lli->lli_sa_lock);
1187 CDEBUG(D_READA, "statahead thread stopped: sai %p, parent %.*s\n",
1188 sai, parent->d_name.len, parent->d_name.name);
1190 wake_up(&sai->sai_waitq);
1191 wake_up(&sa_thread->t_ctl_waitq);
1197 /* authorize opened dir handle @key to statahead */
1198 void ll_authorize_statahead(struct inode *dir, void *key)
1200 struct ll_inode_info *lli = ll_i2info(dir);
1202 spin_lock(&lli->lli_sa_lock);
1203 if (lli->lli_opendir_key == NULL && lli->lli_sai == NULL) {
1205 * if lli_sai is not NULL, it means previous statahead is not
1206 * finished yet, we'd better not start a new statahead for now.
1208 LASSERT(lli->lli_opendir_pid == 0);
1209 lli->lli_opendir_key = key;
1210 lli->lli_opendir_pid = current_pid();
1211 lli->lli_sa_enabled = 1;
1213 spin_unlock(&lli->lli_sa_lock);
1217 * deauthorize opened dir handle @key to statahead, and notify statahead thread
1218 * to quit if it's running.
1220 void ll_deauthorize_statahead(struct inode *dir, void *key)
1222 struct ll_inode_info *lli = ll_i2info(dir);
1223 struct ll_statahead_info *sai;
1225 LASSERT(lli->lli_opendir_key == key);
1226 LASSERT(lli->lli_opendir_pid != 0);
1228 CDEBUG(D_READA, "deauthorize statahead for "DFID"\n",
1229 PFID(&lli->lli_fid));
1231 spin_lock(&lli->lli_sa_lock);
1232 lli->lli_opendir_key = NULL;
1233 lli->lli_opendir_pid = 0;
1234 lli->lli_sa_enabled = 0;
1236 if (sai != NULL && thread_is_running(&sai->sai_thread)) {
1238 * statahead thread may not quit yet because it needs to cache
1239 * entries, now it's time to tell it to quit.
1241 thread_set_flags(&sai->sai_thread, SVC_STOPPING);
1242 wake_up(&sai->sai_thread.t_ctl_waitq);
1244 spin_unlock(&lli->lli_sa_lock);
1249 * not first dirent, or is "."
1251 LS_NOT_FIRST_DE = 0,
1253 * the first non-hidden dirent
1257 * the first hidden dirent, that is "."
1262 /* file is first dirent under @dir */
1263 static int is_first_dirent(struct inode *dir, struct dentry *dentry)
1265 struct ll_dir_chain chain;
1266 struct qstr *target = &dentry->d_name;
1267 struct md_op_data *op_data;
1269 struct page *page = NULL;
1270 int rc = LS_NOT_FIRST_DE;
1274 op_data = ll_prep_md_op_data(NULL, dir, dir, NULL, 0, 0,
1275 LUSTRE_OPC_ANY, dir);
1276 if (IS_ERR(op_data))
1277 RETURN(PTR_ERR(op_data));
1279 *FIXME choose the start offset of the readdir
1281 op_data->op_max_pages = ll_i2sbi(dir)->ll_md_brw_pages;
1283 ll_dir_chain_init(&chain);
1284 page = ll_get_dir_page(dir, op_data, 0, &chain);
1287 struct lu_dirpage *dp;
1288 struct lu_dirent *ent;
1291 struct ll_inode_info *lli = ll_i2info(dir);
1294 CERROR("%s: reading dir "DFID" at "LPU64
1295 "opendir_pid = %u : rc = %d\n",
1296 ll_get_fsname(dir->i_sb, NULL, 0),
1297 PFID(ll_inode2fid(dir)), pos,
1298 lli->lli_opendir_pid, rc);
1302 dp = page_address(page);
1303 for (ent = lu_dirent_start(dp); ent != NULL;
1304 ent = lu_dirent_next(ent)) {
1309 hash = le64_to_cpu(ent->lde_hash);
1310 /* The ll_get_dir_page() can return any page containing
1311 * the given hash which may be not the start hash. */
1312 if (unlikely(hash < pos))
1315 namelen = le16_to_cpu(ent->lde_namelen);
1316 if (unlikely(namelen == 0))
1318 * skip dummy record.
1322 name = ent->lde_name;
1323 if (name[0] == '.') {
1329 else if (name[1] == '.' && namelen == 2)
1340 if (dot_de && target->name[0] != '.') {
1341 CDEBUG(D_READA, "%.*s skip hidden file %.*s\n",
1342 target->len, target->name,
1347 if (target->len != namelen ||
1348 memcmp(target->name, name, namelen) != 0)
1349 rc = LS_NOT_FIRST_DE;
1353 rc = LS_FIRST_DOT_DE;
1355 ll_release_page(dir, page, false);
1358 pos = le64_to_cpu(dp->ldp_hash_end);
1359 if (pos == MDS_DIR_END_OFF) {
1361 * End of directory reached.
1363 ll_release_page(dir, page, false);
1367 * chain is exhausted
1368 * Normal case: continue to the next page.
1370 ll_release_page(dir, page, le32_to_cpu(dp->ldp_flags) &
1372 page = ll_get_dir_page(dir, op_data, pos, &chain);
1377 ll_dir_chain_fini(&chain);
1378 ll_finish_md_op_data(op_data);
1383 * revalidate @dentryp from statahead cache
1385 * \param[in] dir parent directory
1386 * \param[in] sai sai structure
1387 * \param[out] dentryp pointer to dentry which will be revalidated
1388 * \param[in] unplug unplug statahead window only (normally for negative
1390 * \retval 1 on success, dentry is saved in @dentryp
1391 * \retval 0 if revalidation failed (no proper lock on client)
1392 * \retval negative number upon error
1394 static int revalidate_statahead_dentry(struct inode *dir,
1395 struct ll_statahead_info *sai,
1396 struct dentry **dentryp,
1399 struct sa_entry *entry = NULL;
1400 struct l_wait_info lwi = { 0 };
1401 struct ll_dentry_data *ldd;
1402 struct ll_inode_info *lli = ll_i2info(dir);
1406 if ((*dentryp)->d_name.name[0] == '.') {
1407 if (sai->sai_ls_all ||
1408 sai->sai_miss_hidden >= sai->sai_skip_hidden) {
1410 * Hidden dentry is the first one, or statahead
1411 * thread does not skip so many hidden dentries
1412 * before "sai_ls_all" enabled as below.
1415 if (!sai->sai_ls_all)
1417 * It maybe because hidden dentry is not
1418 * the first one, "sai_ls_all" was not
1419 * set, then "ls -al" missed. Enable
1420 * "sai_ls_all" for such case.
1422 sai->sai_ls_all = 1;
1425 * Such "getattr" has been skipped before
1426 * "sai_ls_all" enabled as above.
1428 sai->sai_miss_hidden++;
1436 entry = sa_get(sai, &(*dentryp)->d_name);
1438 GOTO(out, rc = -EAGAIN);
1440 /* if statahead is busy in readdir, help it do post-work */
1441 if (!sa_ready(entry) && sai->sai_in_readpage)
1442 sa_handle_callback(sai);
1444 if (!sa_ready(entry)) {
1445 spin_lock(&lli->lli_sa_lock);
1446 sai->sai_index_wait = entry->se_index;
1447 spin_unlock(&lli->lli_sa_lock);
1448 lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
1449 LWI_ON_SIGNAL_NOOP, NULL);
1450 rc = l_wait_event(sai->sai_waitq, sa_ready(entry), &lwi);
1453 * entry may not be ready, so it may be used by inflight
1454 * statahead RPC, don't free it.
1457 GOTO(out, rc = -EAGAIN);
1461 if (entry->se_state == SA_ENTRY_SUCC && entry->se_inode != NULL) {
1462 struct inode *inode = entry->se_inode;
1463 struct lookup_intent it = { .it_op = IT_GETATTR,
1468 rc = md_revalidate_lock(ll_i2mdexp(dir), &it,
1469 ll_inode2fid(inode), &bits);
1471 if ((*dentryp)->d_inode == NULL) {
1472 struct dentry *alias;
1474 alias = ll_splice_alias(inode, *dentryp);
1475 if (IS_ERR(alias)) {
1476 ll_intent_release(&it);
1477 GOTO(out, rc = PTR_ERR(alias));
1480 /* statahead prepared this inode, transfer inode
1481 * refcount from sa_entry to dentry */
1482 entry->se_inode = NULL;
1483 } else if ((*dentryp)->d_inode != inode) {
1484 /* revalidate, but inode is recreated */
1486 "%s: stale dentry %.*s inode "
1487 DFID", statahead inode "DFID
1489 ll_get_fsname((*dentryp)->d_inode->i_sb,
1491 (*dentryp)->d_name.len,
1492 (*dentryp)->d_name.name,
1493 PFID(ll_inode2fid((*dentryp)->d_inode)),
1494 PFID(ll_inode2fid(inode)));
1495 ll_intent_release(&it);
1496 GOTO(out, rc = -ESTALE);
1499 if ((bits & MDS_INODELOCK_LOOKUP) &&
1500 d_lustre_invalid(*dentryp))
1501 d_lustre_revalidate(*dentryp);
1502 ll_intent_release(&it);
1507 * statahead cached sa_entry can be used only once, and will be killed
1508 * right after use, so if lookup/revalidate accessed statahead cache,
1509 * set dentry ldd_sa_generation to parent lli_sa_generation, later if we
1510 * stat this file again, we know we've done statahead before, see
1511 * dentry_may_statahead().
1513 ldd = ll_d2d(*dentryp);
1514 /* ldd can be NULL if llite lookup failed. */
1516 ldd->lld_sa_generation = lli->lli_sa_generation;
1523 * start statahead thread
1525 * \param[in] dir parent directory
1526 * \param[in] dentry dentry that triggers statahead, normally the first
1528 * \retval -EAGAIN on success, because when this function is
1529 * called, it's already in lookup call, so client should
1530 * do it itself instead of waiting for statahead thread
1531 * to do it asynchronously.
1532 * \retval negative number upon error
1534 static int start_statahead_thread(struct inode *dir, struct dentry *dentry)
1536 struct ll_inode_info *lli = ll_i2info(dir);
1537 struct ll_statahead_info *sai = NULL;
1538 struct dentry *parent = dentry->d_parent;
1539 struct ptlrpc_thread *thread;
1540 struct l_wait_info lwi = { 0 };
1541 struct task_struct *task;
1545 /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
1546 rc = is_first_dirent(dir, dentry);
1547 if (rc == LS_NOT_FIRST_DE)
1548 /* It is not "ls -{a}l" operation, no need statahead for it. */
1549 GOTO(out, rc = -EFAULT);
1551 sai = ll_sai_alloc(parent);
1553 GOTO(out, rc = -ENOMEM);
1555 sai->sai_ls_all = (rc == LS_FIRST_DOT_DE);
1557 /* if current lli_opendir_key was deauthorized, or dir re-opened by
1558 * another process, don't start statahead, otherwise the newly spawned
1559 * statahead thread won't be notified to quit. */
1560 spin_lock(&lli->lli_sa_lock);
1561 if (unlikely(lli->lli_sai != NULL ||
1562 lli->lli_opendir_key == NULL ||
1563 lli->lli_opendir_pid != current->pid)) {
1564 spin_unlock(&lli->lli_sa_lock);
1565 GOTO(out, rc = -EPERM);
1568 spin_unlock(&lli->lli_sa_lock);
1570 atomic_inc(&ll_i2sbi(parent->d_inode)->ll_sa_running);
1572 CDEBUG(D_READA, "start statahead thread: [pid %d] [parent %.*s]\n",
1573 current_pid(), parent->d_name.len, parent->d_name.name);
1575 task = kthread_run(ll_statahead_thread, parent, "ll_sa_%u",
1576 lli->lli_opendir_pid);
1577 thread = &sai->sai_thread;
1580 CERROR("can't start ll_sa thread, rc: %d\n", rc);
1584 l_wait_event(thread->t_ctl_waitq,
1585 thread_is_running(thread) || thread_is_stopped(thread),
1590 * We don't stat-ahead for the first dirent since we are already in
1596 /* once we start statahead thread failed, disable statahead so that
1597 * subsequent stat won't waste time to try it. */
1598 spin_lock(&lli->lli_sa_lock);
1599 lli->lli_sa_enabled = 0;
1600 lli->lli_sai = NULL;
1601 spin_unlock(&lli->lli_sa_lock);
1610 * statahead entry function, this is called when client getattr on a file, it
1611 * will start statahead thread if this is the first dir entry, else revalidate
1612 * dentry from statahead cache.
1614 * \param[in] dir parent directory
1615 * \param[out] dentryp dentry to getattr
1616 * \param[in] unplug unplug statahead window only (normally for negative
1618 * \retval 1 on success
1619 * \retval 0 revalidation from statahead cache failed, caller needs
1620 * to getattr from server directly
1621 * \retval negative number on error, caller often ignores this and
1622 * then getattr from server
1624 int ll_statahead(struct inode *dir, struct dentry **dentryp, bool unplug)
1626 struct ll_statahead_info *sai;
1628 sai = ll_sai_get(dir);
1632 rc = revalidate_statahead_dentry(dir, sai, dentryp, unplug);
1633 CDEBUG(D_READA, "revalidate statahead %.*s: %d.\n",
1634 (*dentryp)->d_name.len, (*dentryp)->d_name.name, rc);
1638 return start_statahead_thread(dir, *dentryp);