1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
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/smp_lock.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_lite.h>
48 #include <lustre_dlm.h>
49 #include <linux/lustre_version.h>
50 #include "llite_internal.h"
54 unsigned int se_index;
56 struct ptlrpc_request *se_req;
57 struct md_enqueue_info *se_minfo;
61 SA_ENTRY_UNSTATED = 0,
65 static unsigned int sai_generation = 0;
66 static cfs_spinlock_t sai_generation_lock = CFS_SPIN_LOCK_UNLOCKED;
69 * Check whether first entry was stated already or not.
70 * No need to hold lli_lock, for:
71 * (1) it is me that remove entry from the list
72 * (2) the statahead thread only add new entry to the list
74 static int ll_sai_entry_stated(struct ll_statahead_info *sai)
76 struct ll_sai_entry *entry;
79 if (!cfs_list_empty(&sai->sai_entries_stated)) {
80 entry = cfs_list_entry(sai->sai_entries_stated.next,
81 struct ll_sai_entry, se_list);
82 if (entry->se_index == sai->sai_index_next)
88 static inline int sa_received_empty(struct ll_statahead_info *sai)
90 return cfs_list_empty(&sai->sai_entries_received);
93 static inline int sa_not_full(struct ll_statahead_info *sai)
95 return (sai->sai_index < sai->sai_hit + sai->sai_miss + sai->sai_max);
98 static inline int sa_is_running(struct ll_statahead_info *sai)
100 return !!(sai->sai_thread.t_flags & SVC_RUNNING);
103 static inline int sa_is_stopping(struct ll_statahead_info *sai)
105 return !!(sai->sai_thread.t_flags & SVC_STOPPING);
108 static inline int sa_is_stopped(struct ll_statahead_info *sai)
110 return !!(sai->sai_thread.t_flags & SVC_STOPPED);
114 * (1) hit ratio less than 80%
116 * (2) consecutive miss more than 8
118 static inline int sa_low_hit(struct ll_statahead_info *sai)
120 return ((sai->sai_hit > 7 && sai->sai_hit < 4 * sai->sai_miss) ||
121 (sai->sai_consecutive_miss > 8));
125 * process the deleted entry's member and free the entry.
127 * (2) free md_enqueue_info
128 * (3) drop dentry's ref count
129 * (4) release request's ref count
131 static void ll_sai_entry_cleanup(struct ll_sai_entry *entry, int free)
133 struct md_enqueue_info *minfo = entry->se_minfo;
134 struct ptlrpc_request *req = entry->se_req;
138 entry->se_minfo = NULL;
139 ll_intent_release(&minfo->mi_it);
140 dput(minfo->mi_dentry);
145 entry->se_req = NULL;
146 ptlrpc_req_finished(req);
149 LASSERT(cfs_list_empty(&entry->se_list));
156 static struct ll_statahead_info *ll_sai_alloc(void)
158 struct ll_statahead_info *sai;
164 cfs_spin_lock(&sai_generation_lock);
165 sai->sai_generation = ++sai_generation;
166 if (unlikely(sai_generation == 0))
167 sai->sai_generation = ++sai_generation;
168 cfs_spin_unlock(&sai_generation_lock);
169 cfs_atomic_set(&sai->sai_refcount, 1);
170 sai->sai_max = LL_SA_RPC_MIN;
171 cfs_waitq_init(&sai->sai_waitq);
172 cfs_waitq_init(&sai->sai_thread.t_ctl_waitq);
173 CFS_INIT_LIST_HEAD(&sai->sai_entries_sent);
174 CFS_INIT_LIST_HEAD(&sai->sai_entries_received);
175 CFS_INIT_LIST_HEAD(&sai->sai_entries_stated);
180 struct ll_statahead_info *ll_sai_get(struct ll_statahead_info *sai)
183 cfs_atomic_inc(&sai->sai_refcount);
187 static void ll_sai_put(struct ll_statahead_info *sai)
189 struct inode *inode = sai->sai_inode;
190 struct ll_inode_info *lli;
193 LASSERT(inode != NULL);
194 lli = ll_i2info(inode);
195 LASSERT(lli->lli_sai == sai);
197 if (cfs_atomic_dec_and_test(&sai->sai_refcount)) {
198 struct ll_sai_entry *entry, *next;
200 cfs_spin_lock(&lli->lli_lock);
201 if (unlikely(cfs_atomic_read(&sai->sai_refcount) > 0)) {
202 /* It is race case, the interpret callback just hold
203 * a reference count */
204 cfs_spin_unlock(&lli->lli_lock);
209 LASSERT(lli->lli_opendir_key == NULL);
211 lli->lli_opendir_pid = 0;
212 cfs_spin_unlock(&lli->lli_lock);
214 LASSERT(sa_is_stopped(sai));
216 if (sai->sai_sent > sai->sai_replied)
217 CDEBUG(D_READA,"statahead for dir "DFID" does not "
218 "finish: [sent:%u] [replied:%u]\n",
220 sai->sai_sent, sai->sai_replied);
222 cfs_list_for_each_entry_safe(entry, next,
223 &sai->sai_entries_sent, se_list) {
224 cfs_list_del_init(&entry->se_list);
225 ll_sai_entry_cleanup(entry, 1);
227 cfs_list_for_each_entry_safe(entry, next,
228 &sai->sai_entries_received,
230 cfs_list_del_init(&entry->se_list);
231 ll_sai_entry_cleanup(entry, 1);
233 cfs_list_for_each_entry_safe(entry, next,
234 &sai->sai_entries_stated,
236 cfs_list_del_init(&entry->se_list);
237 ll_sai_entry_cleanup(entry, 1);
246 * insert it into sai_entries_sent tail when init.
248 static struct ll_sai_entry *
249 ll_sai_entry_init(struct ll_statahead_info *sai, unsigned int index)
251 struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
252 struct ll_sai_entry *entry;
255 OBD_ALLOC_PTR(entry);
257 RETURN(ERR_PTR(-ENOMEM));
259 CDEBUG(D_READA, "alloc sai entry %p index %u\n",
261 entry->se_index = index;
262 entry->se_stat = SA_ENTRY_UNSTATED;
264 cfs_spin_lock(&lli->lli_lock);
265 cfs_list_add_tail(&entry->se_list, &sai->sai_entries_sent);
266 cfs_spin_unlock(&lli->lli_lock);
272 * delete it from sai_entries_stated head when fini, it need not
273 * to process entry's member.
275 static void ll_sai_entry_fini(struct ll_statahead_info *sai)
277 struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
278 struct ll_sai_entry *entry;
281 cfs_spin_lock(&lli->lli_lock);
282 sai->sai_index_next++;
283 if (likely(!cfs_list_empty(&sai->sai_entries_stated))) {
284 entry = cfs_list_entry(sai->sai_entries_stated.next,
285 struct ll_sai_entry, se_list);
286 if (entry->se_index < sai->sai_index_next) {
287 cfs_list_del(&entry->se_list);
291 LASSERT(sa_is_stopped(sai));
292 cfs_spin_unlock(&lli->lli_lock);
299 * \retval NULL : can not find the entry in sai_entries_sent with the index
300 * \retval entry: find the entry in sai_entries_sent with the index
302 static struct ll_sai_entry *
303 ll_sai_entry_set(struct ll_statahead_info *sai, unsigned int index, int stat,
304 struct ptlrpc_request *req, struct md_enqueue_info *minfo)
306 struct ll_sai_entry *entry;
309 if (!cfs_list_empty(&sai->sai_entries_sent)) {
310 cfs_list_for_each_entry(entry, &sai->sai_entries_sent,
312 if (entry->se_index == index) {
313 entry->se_stat = stat;
314 entry->se_req = ptlrpc_request_addref(req);
315 entry->se_minfo = minfo;
317 } else if (entry->se_index > index)
326 * Move entry to sai_entries_received and
327 * insert it into sai_entries_received tail.
330 ll_sai_entry_to_received(struct ll_statahead_info *sai, struct ll_sai_entry *entry)
332 if (!cfs_list_empty(&entry->se_list))
333 cfs_list_del_init(&entry->se_list);
334 cfs_list_add_tail(&entry->se_list, &sai->sai_entries_received);
338 * Move entry to sai_entries_stated and
339 * sort with the index.
342 ll_sai_entry_to_stated(struct ll_statahead_info *sai, struct ll_sai_entry *entry)
344 struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
345 struct ll_sai_entry *se;
348 ll_sai_entry_cleanup(entry, 0);
350 cfs_spin_lock(&lli->lli_lock);
351 if (!cfs_list_empty(&entry->se_list))
352 cfs_list_del_init(&entry->se_list);
354 if (unlikely(entry->se_index < sai->sai_index_next)) {
355 cfs_spin_unlock(&lli->lli_lock);
360 cfs_list_for_each_entry_reverse(se, &sai->sai_entries_stated, se_list) {
361 if (se->se_index < entry->se_index) {
362 cfs_list_add(&entry->se_list, &se->se_list);
363 cfs_spin_unlock(&lli->lli_lock);
369 * I am the first entry.
371 cfs_list_add(&entry->se_list, &sai->sai_entries_stated);
372 cfs_spin_unlock(&lli->lli_lock);
377 * finish lookup/revalidate.
379 static int do_statahead_interpret(struct ll_statahead_info *sai)
381 struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
382 struct ll_sai_entry *entry;
383 struct ptlrpc_request *req;
384 struct md_enqueue_info *minfo;
385 struct lookup_intent *it;
386 struct dentry *dentry;
388 struct mdt_body *body;
391 cfs_spin_lock(&lli->lli_lock);
392 LASSERT(!sa_received_empty(sai));
393 entry = cfs_list_entry(sai->sai_entries_received.next,
394 struct ll_sai_entry, se_list);
395 cfs_list_del_init(&entry->se_list);
396 cfs_spin_unlock(&lli->lli_lock);
398 if (unlikely(entry->se_index < sai->sai_index_next)) {
399 CWARN("Found stale entry: [index %u] [next %u]\n",
400 entry->se_index, sai->sai_index_next);
401 ll_sai_entry_cleanup(entry, 1);
405 if (entry->se_stat != SA_ENTRY_STATED)
406 GOTO(out, rc = entry->se_stat);
409 minfo = entry->se_minfo;
411 dentry = minfo->mi_dentry;
413 body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
415 GOTO(out, rc = -EFAULT);
417 if (dentry->d_inode == NULL) {
421 struct dentry *save = dentry;
422 struct it_cb_data icbd = {
423 .icbd_parent = minfo->mi_dir,
424 .icbd_childp = &dentry
427 LASSERT(fid_is_zero(&minfo->mi_data.op_fid2));
430 * XXX: No fid in reply, this is probaly cross-ref case.
431 * SA can't handle it yet.
433 if (body->valid & OBD_MD_MDS)
434 GOTO(out, rc = -EAGAIN);
436 rc = ll_lookup_it_finish(req, it, &icbd);
439 * Here dentry->d_inode might be NULL,
440 * because the entry may have been removed before
441 * we start doing stat ahead.
443 ll_lookup_finish_locks(it, dentry);
445 if (dentry != save) {
446 minfo->mi_dentry = dentry;
453 if (!lu_fid_eq(&minfo->mi_data.op_fid2, &body->fid1)) {
454 ll_unhash_aliases(dentry->d_inode);
455 GOTO(out, rc = -EAGAIN);
458 rc = ll_revalidate_it_finish(req, it, dentry);
460 ll_unhash_aliases(dentry->d_inode);
464 cfs_spin_lock(&ll_lookup_lock);
465 spin_lock(&dcache_lock);
468 dentry->d_flags &= ~DCACHE_LUSTRE_INVALID;
469 unlock_dentry(dentry);
470 d_rehash_cond(dentry, 0);
471 spin_unlock(&dcache_lock);
472 cfs_spin_unlock(&ll_lookup_lock);
474 ll_lookup_finish_locks(it, dentry);
479 if (likely(ll_sai_entry_to_stated(sai, entry)))
480 cfs_waitq_signal(&sai->sai_waitq);
484 static int ll_statahead_interpret(struct ptlrpc_request *req,
485 struct md_enqueue_info *minfo,
488 struct lookup_intent *it = &minfo->mi_it;
489 struct dentry *dentry = minfo->mi_dentry;
490 struct inode *dir = minfo->mi_dir;
491 struct ll_inode_info *lli = ll_i2info(dir);
492 struct ll_statahead_info *sai;
493 struct ll_sai_entry *entry;
496 CDEBUG(D_READA, "interpret statahead %.*s rc %d\n",
497 dentry->d_name.len, dentry->d_name.name, rc);
499 cfs_spin_lock(&lli->lli_lock);
500 if (unlikely(lli->lli_sai == NULL ||
501 lli->lli_sai->sai_generation != minfo->mi_generation)) {
502 cfs_spin_unlock(&lli->lli_lock);
503 ll_intent_release(it);
509 sai = ll_sai_get(lli->lli_sai);
510 entry = ll_sai_entry_set(sai,
511 (unsigned int)(long)minfo->mi_cbdata,
512 rc ? SA_ENTRY_UNSTATED :
513 SA_ENTRY_STATED, req, minfo);
514 LASSERT(entry != NULL);
515 if (likely(sa_is_running(sai))) {
516 ll_sai_entry_to_received(sai, entry);
518 cfs_spin_unlock(&lli->lli_lock);
519 cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq);
521 if (!cfs_list_empty(&entry->se_list))
522 cfs_list_del_init(&entry->se_list);
524 cfs_spin_unlock(&lli->lli_lock);
525 ll_sai_entry_cleanup(entry, 1);
532 static void sa_args_fini(struct md_enqueue_info *minfo,
533 struct ldlm_enqueue_info *einfo)
535 LASSERT(minfo && einfo);
537 capa_put(minfo->mi_data.op_capa1);
538 capa_put(minfo->mi_data.op_capa2);
544 * There is race condition between "capa_put" and "ll_statahead_interpret" for
545 * accessing "op_data.op_capa[1,2]" as following:
546 * "capa_put" releases "op_data.op_capa[1,2]"'s reference count after calling
547 * "md_intent_getattr_async". But "ll_statahead_interpret" maybe run first, and
548 * fill "op_data.op_capa[1,2]" as POISON, then cause "capa_put" access invalid
549 * "ocapa". So here reserve "op_data.op_capa[1,2]" in "pcapa" before calling
550 * "md_intent_getattr_async".
552 static int sa_args_init(struct inode *dir, struct dentry *dentry,
553 struct md_enqueue_info **pmi,
554 struct ldlm_enqueue_info **pei,
555 struct obd_capa **pcapa)
557 struct ll_inode_info *lli = ll_i2info(dir);
558 struct md_enqueue_info *minfo;
559 struct ldlm_enqueue_info *einfo;
560 struct md_op_data *op_data;
562 OBD_ALLOC_PTR(einfo);
566 OBD_ALLOC_PTR(minfo);
572 op_data = ll_prep_md_op_data(&minfo->mi_data, dir, dentry->d_inode,
573 dentry->d_name.name, dentry->d_name.len,
574 0, LUSTRE_OPC_ANY, NULL);
575 if (IS_ERR(op_data)) {
578 return PTR_ERR(op_data);
581 minfo->mi_it.it_op = IT_GETATTR;
582 minfo->mi_dentry = dentry;
583 minfo->mi_dir = igrab(dir);
584 minfo->mi_cb = ll_statahead_interpret;
585 minfo->mi_generation = lli->lli_sai->sai_generation;
586 minfo->mi_cbdata = (void *)(long)lli->lli_sai->sai_index;
588 einfo->ei_type = LDLM_IBITS;
589 einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
590 einfo->ei_cb_bl = ll_md_blocking_ast;
591 einfo->ei_cb_cp = ldlm_completion_ast;
592 einfo->ei_cb_gl = NULL;
593 einfo->ei_cbdata = NULL;
597 pcapa[0] = op_data->op_capa1;
598 pcapa[1] = op_data->op_capa2;
604 * similar to ll_lookup_it().
606 static int do_sa_lookup(struct inode *dir, struct dentry *dentry)
608 struct md_enqueue_info *minfo;
609 struct ldlm_enqueue_info *einfo;
610 struct obd_capa *capas[2];
614 rc = sa_args_init(dir, dentry, &minfo, &einfo, capas);
618 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
623 sa_args_fini(minfo, einfo);
630 * similar to ll_revalidate_it().
631 * \retval 1 -- dentry valid
632 * \retval 0 -- will send stat-ahead request
633 * \retval others -- prepare stat-ahead request failed
635 static int do_sa_revalidate(struct inode *dir, struct dentry *dentry)
637 struct inode *inode = dentry->d_inode;
638 struct lookup_intent it = { .it_op = IT_GETATTR };
639 struct md_enqueue_info *minfo;
640 struct ldlm_enqueue_info *einfo;
641 struct obd_capa *capas[2];
648 if (d_mountpoint(dentry))
651 if (dentry == dentry->d_sb->s_root)
654 rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode));
656 ll_intent_release(&it);
660 rc = sa_args_init(dir, dentry, &minfo, &einfo, capas);
664 rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
669 sa_args_fini(minfo, einfo);
675 static inline void ll_name2qstr(struct qstr *q, const char *name, int namelen)
679 q->hash = full_name_hash(name, namelen);
682 static int ll_statahead_one(struct dentry *parent, const char* entry_name,
685 struct inode *dir = parent->d_inode;
686 struct ll_inode_info *lli = ll_i2info(dir);
687 struct ll_statahead_info *sai = lli->lli_sai;
689 struct dentry *dentry;
690 struct ll_sai_entry *se;
694 if (parent->d_flags & DCACHE_LUSTRE_INVALID) {
695 CDEBUG(D_READA, "parent dentry@%p %.*s is "
696 "invalid, skip statahead\n",
697 parent, parent->d_name.len, parent->d_name.name);
701 se = ll_sai_entry_init(sai, sai->sai_index);
705 ll_name2qstr(&name, entry_name, entry_name_len);
706 dentry = d_lookup(parent, &name);
708 dentry = d_alloc(parent, &name);
710 rc = do_sa_lookup(dir, dentry);
714 GOTO(out, rc = -ENOMEM);
717 rc = do_sa_revalidate(dir, dentry);
726 CDEBUG(D_READA, "set sai entry %p index %u stat %d rc %d\n",
727 se, se->se_index, se->se_stat, rc);
729 if (ll_sai_entry_to_stated(sai, se))
730 cfs_waitq_signal(&sai->sai_waitq);
739 static int ll_statahead_thread(void *arg)
741 struct dentry *parent = (struct dentry *)arg;
742 struct inode *dir = parent->d_inode;
743 struct ll_inode_info *lli = ll_i2info(dir);
744 struct ll_sb_info *sbi = ll_i2sbi(dir);
745 struct ll_statahead_info *sai = ll_sai_get(lli->lli_sai);
746 struct ptlrpc_thread *thread = &sai->sai_thread;
751 struct ll_dir_chain chain;
756 snprintf(pname, 15, "ll_sa_%u", lli->lli_opendir_pid);
757 cfs_daemonize(pname);
761 cfs_spin_lock(&lli->lli_lock);
762 thread->t_flags = SVC_RUNNING;
763 cfs_spin_unlock(&lli->lli_lock);
764 cfs_waitq_signal(&thread->t_ctl_waitq);
765 CDEBUG(D_READA, "start doing statahead for %s\n", parent->d_name.name);
767 ll_dir_chain_init(&chain);
768 page = ll_get_dir_page(dir, pos, 0, &chain);
771 struct l_wait_info lwi = { 0 };
772 struct lu_dirpage *dp;
773 struct lu_dirent *ent;
777 CDEBUG(D_READA, "error reading dir "DFID" at "LPU64"/%u: rc %d\n",
778 PFID(ll_inode2fid(dir)), pos,
783 dp = page_address(page);
784 for (ent = lu_dirent_start(dp); ent != NULL;
785 ent = lu_dirent_next(ent)) {
786 char *name = ent->lde_name;
787 int namelen = le16_to_cpu(ent->lde_namelen);
795 if (name[0] == '.') {
801 } else if (name[1] == '.' && namelen == 2) {
806 } else if (!sai->sai_ls_all) {
810 sai->sai_skip_hidden++;
816 * don't stat-ahead first entry.
818 if (unlikely(!first)) {
824 l_wait_event(thread->t_ctl_waitq,
825 !sa_is_running(sai) || sa_not_full(sai) ||
826 !sa_received_empty(sai),
829 while (!sa_received_empty(sai) && sa_is_running(sai))
830 do_statahead_interpret(sai);
832 if (unlikely(!sa_is_running(sai))) {
837 if (!sa_not_full(sai))
839 * do not skip the current de.
843 rc = ll_statahead_one(parent, name, namelen);
849 pos = le64_to_cpu(dp->ldp_hash_end);
851 if (pos == DIR_END_OFF) {
853 * End of directory reached.
856 l_wait_event(thread->t_ctl_waitq,
857 !sa_is_running(sai) ||
858 !sa_received_empty(sai) ||
859 sai->sai_sent == sai->sai_replied,
861 if (!sa_received_empty(sai) &&
863 do_statahead_interpret(sai);
869 * chain is exhausted.
870 * Normal case: continue to the next page.
872 page = ll_get_dir_page(dir, pos, 1, &chain);
875 * go into overflow page.
882 ll_dir_chain_fini(&chain);
883 cfs_spin_lock(&lli->lli_lock);
884 thread->t_flags = SVC_STOPPED;
885 cfs_spin_unlock(&lli->lli_lock);
886 cfs_waitq_signal(&sai->sai_waitq);
887 cfs_waitq_signal(&thread->t_ctl_waitq);
890 CDEBUG(D_READA, "statahead thread stopped, pid %d\n",
896 * called in ll_file_release().
898 void ll_stop_statahead(struct inode *inode, void *key)
900 struct ll_inode_info *lli = ll_i2info(inode);
902 if (unlikely(key == NULL))
905 cfs_spin_lock(&lli->lli_lock);
906 if (lli->lli_opendir_key != key || lli->lli_opendir_pid == 0) {
907 cfs_spin_unlock(&lli->lli_lock);
911 lli->lli_opendir_key = NULL;
914 struct l_wait_info lwi = { 0 };
915 struct ptlrpc_thread *thread = &lli->lli_sai->sai_thread;
917 if (!sa_is_stopped(lli->lli_sai)) {
918 thread->t_flags = SVC_STOPPING;
919 cfs_spin_unlock(&lli->lli_lock);
920 cfs_waitq_signal(&thread->t_ctl_waitq);
922 CDEBUG(D_READA, "stopping statahead thread, pid %d\n",
924 l_wait_event(thread->t_ctl_waitq,
925 sa_is_stopped(lli->lli_sai),
928 cfs_spin_unlock(&lli->lli_lock);
932 * Put the ref which was held when first statahead_enter.
933 * It maybe not the last ref for some statahead requests
936 ll_sai_put(lli->lli_sai);
938 lli->lli_opendir_pid = 0;
939 cfs_spin_unlock(&lli->lli_lock);
945 * not first dirent, or is "."
947 LS_NONE_FIRST_DE = 0,
949 * the first non-hidden dirent
953 * the first hidden dirent, that is "."
958 static int is_first_dirent(struct inode *dir, struct dentry *dentry)
960 struct ll_dir_chain chain;
961 struct qstr *target = &dentry->d_name;
965 int rc = LS_NONE_FIRST_DE;
968 ll_dir_chain_init(&chain);
969 page = ll_get_dir_page(dir, pos, 0, &chain);
972 struct lu_dirpage *dp;
973 struct lu_dirent *ent;
977 CERROR("error reading dir "DFID" at "LPU64": rc %d\n",
978 PFID(ll_inode2fid(dir)), pos, rc);
982 dp = page_address(page);
983 for (ent = lu_dirent_start(dp); ent != NULL;
984 ent = lu_dirent_next(ent)) {
985 char *name = ent->lde_name;
986 int namelen = le16_to_cpu(ent->lde_namelen);
994 if (name[0] == '.') {
1000 else if (name[1] == '.' && namelen == 2)
1011 if (dot_de && target->name[0] != '.') {
1012 CDEBUG(D_READA, "%.*s skip hidden file %.*s\n",
1013 target->len, target->name,
1018 if (target->len != namelen ||
1019 memcmp(target->name, name, namelen) != 0)
1020 rc = LS_NONE_FIRST_DE;
1024 rc = LS_FIRST_DOT_DE;
1029 pos = le64_to_cpu(dp->ldp_hash_end);
1031 if (pos == DIR_END_OFF) {
1033 * End of directory reached.
1038 * chain is exhausted
1039 * Normal case: continue to the next page.
1041 page = ll_get_dir_page(dir, pos, 1, &chain);
1044 * go into overflow page.
1051 ll_dir_chain_fini(&chain);
1056 * Start statahead thread if this is the first dir entry.
1057 * Otherwise if a thread is started already, wait it until it is ahead of me.
1058 * \retval 0 -- stat ahead thread process such dentry, for lookup, it miss
1059 * \retval 1 -- stat ahead thread process such dentry, for lookup, it hit
1060 * \retval -EEXIST -- stat ahead thread started, and this is the first dentry
1061 * \retval -EBADFD -- statahead thread exit and not dentry available
1062 * \retval -EAGAIN -- try to stat by caller
1063 * \retval others -- error
1065 int do_statahead_enter(struct inode *dir, struct dentry **dentryp, int lookup)
1067 struct ll_inode_info *lli;
1068 struct ll_statahead_info *sai;
1069 struct dentry *parent;
1070 struct l_wait_info lwi = { 0 };
1074 LASSERT(dir != NULL);
1075 lli = ll_i2info(dir);
1076 LASSERT(lli->lli_opendir_pid == cfs_curproc_pid());
1080 struct ll_sb_info *sbi;
1082 if (unlikely(sa_is_stopped(sai) &&
1083 cfs_list_empty(&sai->sai_entries_stated)))
1086 if ((*dentryp)->d_name.name[0] == '.') {
1087 if (likely(sai->sai_ls_all ||
1088 sai->sai_miss_hidden >= sai->sai_skip_hidden)) {
1090 * Hidden dentry is the first one, or statahead
1091 * thread does not skip so many hidden dentries
1092 * before "sai_ls_all" enabled as below.
1095 if (!sai->sai_ls_all)
1097 * It maybe because hidden dentry is not
1098 * the first one, "sai_ls_all" was not
1099 * set, then "ls -al" missed. Enable
1100 * "sai_ls_all" for such case.
1102 sai->sai_ls_all = 1;
1105 * Such "getattr" has been skipped before
1106 * "sai_ls_all" enabled as above.
1108 sai->sai_miss_hidden++;
1113 sbi = ll_i2sbi(dir);
1114 if (ll_sai_entry_stated(sai)) {
1115 sbi->ll_sa_cached++;
1117 sbi->ll_sa_blocked++;
1119 * thread started already, avoid double-stat.
1121 lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
1122 rc = l_wait_event(sai->sai_waitq,
1123 ll_sai_entry_stated(sai) ||
1129 struct dentry *result;
1131 result = d_lookup((*dentryp)->d_parent,
1132 &(*dentryp)->d_name);
1134 LASSERT(result != *dentryp);
1135 /* BUG 16303: do not drop reference count for
1136 * "*dentryp", VFS will do that by itself. */
1142 * do nothing for revalidate.
1147 /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
1148 rc = is_first_dirent(dir, *dentryp);
1149 if (rc == LS_NONE_FIRST_DE)
1150 /* It is not "ls -{a}l" operation, no need statahead for it. */
1151 GOTO(out, rc = -EAGAIN);
1153 sai = ll_sai_alloc();
1155 GOTO(out, rc = -ENOMEM);
1157 sai->sai_ls_all = (rc == LS_FIRST_DOT_DE);
1158 sai->sai_inode = igrab(dir);
1159 if (unlikely(sai->sai_inode == NULL)) {
1160 CWARN("Do not start stat ahead on dying inode "DFID" .\n",
1161 PFID(&lli->lli_fid));
1163 GOTO(out, rc = -ESTALE);
1166 /* get parent reference count here, and put it in ll_statahead_thread */
1167 parent = dget((*dentryp)->d_parent);
1168 if (unlikely(sai->sai_inode != parent->d_inode)) {
1169 struct ll_inode_info *nlli = ll_i2info(parent->d_inode);
1171 CWARN("Race condition, someone changed %.*s just now: "
1172 "old parent "DFID", new parent "DFID" .\n",
1173 (*dentryp)->d_name.len, (*dentryp)->d_name.name,
1174 PFID(&lli->lli_fid), PFID(&nlli->lli_fid));
1176 iput(sai->sai_inode);
1182 rc = cfs_kernel_thread(ll_statahead_thread, parent, 0);
1184 CERROR("can't start ll_sa thread, rc: %d\n", rc);
1186 lli->lli_opendir_key = NULL;
1187 sai->sai_thread.t_flags = SVC_STOPPED;
1189 LASSERT(lli->lli_sai == NULL);
1193 l_wait_event(sai->sai_thread.t_ctl_waitq,
1194 sa_is_running(sai) || sa_is_stopped(sai),
1198 * We don't stat-ahead for the first dirent since we are already in
1199 * lookup, and -EEXIST also indicates that this is the first dirent.
1204 cfs_spin_lock(&lli->lli_lock);
1205 lli->lli_opendir_key = NULL;
1206 lli->lli_opendir_pid = 0;
1207 cfs_spin_unlock(&lli->lli_lock);
1212 * update hit/miss count.
1214 void ll_statahead_exit(struct inode *dir, struct dentry *dentry, int result)
1216 struct ll_inode_info *lli;
1217 struct ll_statahead_info *sai;
1218 struct ll_sb_info *sbi;
1219 struct ll_dentry_data *ldd = ll_d2d(dentry);
1222 LASSERT(dir != NULL);
1223 lli = ll_i2info(dir);
1224 LASSERT(lli->lli_opendir_pid == cfs_curproc_pid());
1226 LASSERT(sai != NULL);
1227 sbi = ll_i2sbi(dir);
1232 sai->sai_consecutive_miss = 0;
1233 sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max);
1237 sai->sai_consecutive_miss++;
1238 if (sa_low_hit(sai) && sa_is_running(sai)) {
1240 CDEBUG(D_READA, "Statahead for dir "DFID" hit ratio "
1241 "too low: hit/miss %u/%u, sent/replied %u/%u, "
1242 "stopping statahead thread: pid %d\n",
1243 PFID(&lli->lli_fid), sai->sai_hit,
1244 sai->sai_miss, sai->sai_sent,
1245 sai->sai_replied, cfs_curproc_pid());
1246 cfs_spin_lock(&lli->lli_lock);
1247 if (!sa_is_stopped(sai))
1248 sai->sai_thread.t_flags = SVC_STOPPING;
1249 cfs_spin_unlock(&lli->lli_lock);
1253 if (!sa_is_stopped(sai))
1254 cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq);
1255 ll_sai_entry_fini(sai);
1256 if (likely(ldd != NULL))
1257 ldd->lld_sa_generation = sai->sai_generation;