X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fllite%2Fstatahead.c;h=9eea49e0f02735e18b8887ba70901ac0f380ea6b;hp=c2780caecd266e701d2128581f713d88622975ab;hb=20dfdeda5ea3f679b68c4a9fb6924c90a0a79cac;hpb=4cc21ecbcee4d29017fe5d400f3a88321d65d58d diff --git a/lustre/llite/statahead.c b/lustre/llite/statahead.c index c2780ca..9eea49e 100644 --- a/lustre/llite/statahead.c +++ b/lustre/llite/statahead.c @@ -1,28 +1,42 @@ -/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- - * vim:expandtab:shiftwidth=8:tabstop=8: +/* + * GPL HEADER START * - * Copyright (c) 2007 Cluster File Systems, Inc. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * - * This file is part of Lustre, http://www.lustre.org. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. * - * Lustre is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). * - * Lustre is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf * - * You should have received a copy of the GNU General Public License - * along with Lustre; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2011, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. */ #include #include #include -#include #include #include @@ -31,287 +45,751 @@ #include #include #include -#include #include "llite_internal.h" -struct ll_sai_entry { - struct list_head se_list; - unsigned int se_index; - int se_stat; -}; - -enum { - SA_ENTRY_UNSTATED = 0, - SA_ENTRY_STATED +#define SA_OMITTED_ENTRY_MAX 8ULL + +typedef enum { + /** negative values are for error cases */ + SA_ENTRY_INIT = 0, /** init entry */ + SA_ENTRY_SUCC = 1, /** stat succeed */ + SA_ENTRY_INVA = 2, /** invalid entry */ + SA_ENTRY_DEST = 3, /** entry to be destroyed */ +} se_stat_t; + +struct ll_sa_entry { + /* link into sai->sai_entries_{sent,received,stated} */ + cfs_list_t se_list; + /* link into sai hash table locally */ + cfs_list_t se_hash; + /* entry reference count */ + cfs_atomic_t se_refcount; + /* entry index in the sai */ + __u64 se_index; + /* low layer ldlm lock handle */ + __u64 se_handle; + /* entry status */ + se_stat_t se_stat; + /* entry size, contains name */ + int se_size; + /* pointer to async getattr enqueue info */ + struct md_enqueue_info *se_minfo; + /* pointer to the async getattr request */ + struct ptlrpc_request *se_req; + /* pointer to the target inode */ + struct inode *se_inode; + /* entry name */ + struct qstr se_qstr; }; static unsigned int sai_generation = 0; -static spinlock_t sai_generation_lock = SPIN_LOCK_UNLOCKED; +static DEFINE_SPINLOCK(sai_generation_lock); -static struct ll_statahead_info *ll_sai_alloc(void) +static inline int ll_sa_entry_unlinked(struct ll_sa_entry *entry) { - struct ll_statahead_info *sai; + return cfs_list_empty(&entry->se_list); +} - OBD_ALLOC_PTR(sai); - if (!sai) - return NULL; - - spin_lock(&sai_generation_lock); - sai->sai_generation = ++sai_generation; - if (unlikely(sai_generation == 0)) - sai->sai_generation = ++sai_generation; - spin_unlock(&sai_generation_lock); - atomic_set(&sai->sai_refcount, 1); - sai->sai_max = LL_SA_RPC_MIN; - cfs_waitq_init(&sai->sai_waitq); - cfs_waitq_init(&sai->sai_thread.t_ctl_waitq); - CFS_INIT_LIST_HEAD(&sai->sai_entries); - return sai; +static inline int ll_sa_entry_unhashed(struct ll_sa_entry *entry) +{ + return cfs_list_empty(&entry->se_hash); } -static inline -struct ll_statahead_info *ll_sai_get(struct ll_statahead_info *sai) +/* + * The entry only can be released by the caller, it is necessary to hold lock. + */ +static inline int ll_sa_entry_stated(struct ll_sa_entry *entry) { - LASSERT(sai); - atomic_inc(&sai->sai_refcount); - return sai; + smp_rmb(); + return (entry->se_stat != SA_ENTRY_INIT); } -static void ll_sai_put(struct ll_statahead_info *sai) +static inline int ll_sa_entry_hash(int val) { - struct inode *inode = sai->sai_inode; - struct ll_inode_info *lli = ll_i2info(inode); - ENTRY; + return val & LL_SA_CACHE_MASK; +} - if (atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_lock)) { - struct ll_sai_entry *entry, *next; +/* + * Insert entry to hash SA table. + */ +static inline void +ll_sa_entry_enhash(struct ll_statahead_info *sai, struct ll_sa_entry *entry) +{ + int i = ll_sa_entry_hash(entry->se_qstr.hash); - lli->lli_sai = NULL; - spin_unlock(&lli->lli_lock); + spin_lock(&sai->sai_cache_lock[i]); + cfs_list_add_tail(&entry->se_hash, &sai->sai_cache[i]); + spin_unlock(&sai->sai_cache_lock[i]); +} - LASSERT(sai->sai_thread.t_flags & SVC_STOPPED); +/* + * Remove entry from SA table. + */ +static inline void +ll_sa_entry_unhash(struct ll_statahead_info *sai, struct ll_sa_entry *entry) +{ + int i = ll_sa_entry_hash(entry->se_qstr.hash); - if (sai->sai_sent > sai->sai_replied) - CDEBUG(D_READA,"statahead for dir "DFID" does not " - "finish: [sent:%u] [replied:%u]\n", - PFID(&lli->lli_fid), - sai->sai_sent, sai->sai_replied); + spin_lock(&sai->sai_cache_lock[i]); + cfs_list_del_init(&entry->se_hash); + spin_unlock(&sai->sai_cache_lock[i]); +} - list_for_each_entry_safe(entry, next, &sai->sai_entries, - se_list) { - list_del(&entry->se_list); - OBD_FREE_PTR(entry); - } - OBD_FREE_PTR(sai); - iput(inode); - } - EXIT; +static inline int agl_should_run(struct ll_statahead_info *sai, + struct inode *inode) +{ + return (inode != NULL && S_ISREG(inode->i_mode) && sai->sai_agl_valid); +} + +static inline struct ll_sa_entry * +sa_first_received_entry(struct ll_statahead_info *sai) +{ + return cfs_list_entry(sai->sai_entries_received.next, + struct ll_sa_entry, se_list); +} + +static inline struct ll_inode_info * +agl_first_entry(struct ll_statahead_info *sai) +{ + return cfs_list_entry(sai->sai_entries_agl.next, + struct ll_inode_info, lli_agl_list); +} + +static inline int sa_sent_full(struct ll_statahead_info *sai) +{ + return cfs_atomic_read(&sai->sai_cache_count) >= sai->sai_max; +} + +static inline int sa_received_empty(struct ll_statahead_info *sai) +{ + return cfs_list_empty(&sai->sai_entries_received); +} + +static inline int agl_list_empty(struct ll_statahead_info *sai) +{ + return cfs_list_empty(&sai->sai_entries_agl); } -static struct ll_sai_entry * -ll_sai_entry_get(struct ll_statahead_info *sai, unsigned int index, int stat) +/** + * (1) hit ratio less than 80% + * or + * (2) consecutive miss more than 8 + * then means low hit. + */ +static inline int sa_low_hit(struct ll_statahead_info *sai) { - struct ll_inode_info *lli = ll_i2info(sai->sai_inode); - struct ll_sai_entry *entry; + return ((sai->sai_hit > 7 && sai->sai_hit < 4 * sai->sai_miss) || + (sai->sai_consecutive_miss > 8)); +} + +/* + * If the given index is behind of statahead window more than + * SA_OMITTED_ENTRY_MAX, then it is old. + */ +static inline int is_omitted_entry(struct ll_statahead_info *sai, __u64 index) +{ + return ((__u64)sai->sai_max + index + SA_OMITTED_ENTRY_MAX < + sai->sai_index); +} + +/* + * Insert it into sai_entries_sent tail when init. + */ +static struct ll_sa_entry * +ll_sa_entry_alloc(struct ll_statahead_info *sai, __u64 index, + const char *name, int len) +{ + struct ll_inode_info *lli; + struct ll_sa_entry *entry; + int entry_size; + char *dname; ENTRY; - OBD_ALLOC_PTR(entry); - if (entry == NULL) + entry_size = sizeof(struct ll_sa_entry) + (len & ~3) + 4; + OBD_ALLOC(entry, entry_size); + if (unlikely(entry == NULL)) RETURN(ERR_PTR(-ENOMEM)); - CDEBUG(D_READA, "alloc sai entry %p index %u, stat %d\n", - entry, index, stat); + CDEBUG(D_READA, "alloc sai entry %.*s(%p) index "LPU64"\n", + len, name, entry, index); + entry->se_index = index; - entry->se_stat = stat; - spin_lock(&lli->lli_lock); - list_add_tail(&entry->se_list, &sai->sai_entries); - spin_unlock(&lli->lli_lock); + /* + * Statahead entry reference rules: + * + * 1) When statahead entry is initialized, its reference is set as 2. + * One reference is used by the directory scanner. When the scanner + * searches the statahead cache for the given name, it can perform + * lockless hash lookup (only the scanner can remove entry from hash + * list), and once found, it needn't to call "atomic_inc()" for the + * entry reference. So the performance is improved. After using the + * statahead entry, the scanner will call "atomic_dec()" to drop the + * reference held when initialization. If it is the last reference, + * the statahead entry will be freed. + * + * 2) All other threads, including statahead thread and ptlrpcd thread, + * when they process the statahead entry, the reference for target + * should be held to guarantee the entry will not be released by the + * directory scanner. After processing the entry, these threads will + * drop the entry reference. If it is the last reference, the entry + * will be freed. + * + * The second reference when initializes the statahead entry is used + * by the statahead thread, following the rule 2). + */ + cfs_atomic_set(&entry->se_refcount, 2); + entry->se_stat = SA_ENTRY_INIT; + entry->se_size = entry_size; + dname = (char *)entry + sizeof(struct ll_sa_entry); + memcpy(dname, name, len); + dname[len] = 0; + entry->se_qstr.hash = full_name_hash(name, len); + entry->se_qstr.len = len; + entry->se_qstr.name = dname; + + lli = ll_i2info(sai->sai_inode); + spin_lock(&lli->lli_sa_lock); + cfs_list_add_tail(&entry->se_list, &sai->sai_entries_sent); + spin_unlock(&lli->lli_sa_lock); + + cfs_atomic_inc(&sai->sai_cache_count); + ll_sa_entry_enhash(sai, entry); + + RETURN(entry); +} - RETURN(entry); +/* + * Used by the directory scanner to search entry with name. + * + * Only the caller can remove the entry from hash, so it is unnecessary to hold + * hash lock. It is caller's duty to release the init refcount on the entry, so + * it is also unnecessary to increase refcount on the entry. + */ +static struct ll_sa_entry * +ll_sa_entry_get_byname(struct ll_statahead_info *sai, const struct qstr *qstr) +{ + struct ll_sa_entry *entry; + int i = ll_sa_entry_hash(qstr->hash); + + cfs_list_for_each_entry(entry, &sai->sai_cache[i], se_hash) { + if (entry->se_qstr.hash == qstr->hash && + entry->se_qstr.len == qstr->len && + memcmp(entry->se_qstr.name, qstr->name, qstr->len) == 0) + return entry; + } + return NULL; } -/* inside lli_lock - * return value: - * 0: can not find the entry with the index - * 1: it is the first entry - * 2: it is not the first entry */ -static int -ll_sai_entry_set(struct ll_statahead_info *sai, unsigned int index, int stat) +/* + * Used by the async getattr request callback to find entry with index. + * + * Inside lli_sa_lock to prevent others to change the list during the search. + * It needs to increase entry refcount before returning to guarantee that the + * entry cannot be freed by others. + */ +static struct ll_sa_entry * +ll_sa_entry_get_byindex(struct ll_statahead_info *sai, __u64 index) { - struct ll_sai_entry *entry; - int rc = 0; - ENTRY; + struct ll_sa_entry *entry; - if (list_empty(&sai->sai_entries)) - RETURN(0); + cfs_list_for_each_entry(entry, &sai->sai_entries_sent, se_list) { + if (entry->se_index == index) { + cfs_atomic_inc(&entry->se_refcount); + return entry; + } + if (entry->se_index > index) + break; + } + return NULL; +} - entry = list_entry(sai->sai_entries.next, struct ll_sai_entry, se_list); - if (entry->se_index == index) - GOTO(out, rc = 1); +static void ll_sa_entry_cleanup(struct ll_statahead_info *sai, + struct ll_sa_entry *entry) +{ + struct md_enqueue_info *minfo = entry->se_minfo; + struct ptlrpc_request *req = entry->se_req; - while (entry->se_list.next != &sai->sai_entries && - entry->se_index < index) { - entry = list_entry(entry->se_list.next, struct ll_sai_entry, - se_list); - if (entry->se_index == index) - GOTO(out, rc = 2); + if (minfo) { + entry->se_minfo = NULL; + ll_intent_release(&minfo->mi_it); + iput(minfo->mi_dir); + OBD_FREE_PTR(minfo); } - EXIT; + if (req) { + entry->se_req = NULL; + ptlrpc_req_finished(req); + } +} -out: - if (rc) { - LASSERT(entry->se_stat == SA_ENTRY_UNSTATED); - entry->se_stat = stat; +static void ll_sa_entry_put(struct ll_statahead_info *sai, + struct ll_sa_entry *entry) +{ + if (cfs_atomic_dec_and_test(&entry->se_refcount)) { + CDEBUG(D_READA, "free sai entry %.*s(%p) index "LPU64"\n", + entry->se_qstr.len, entry->se_qstr.name, entry, + entry->se_index); + + LASSERT(ll_sa_entry_unhashed(entry)); + LASSERT(ll_sa_entry_unlinked(entry)); + + ll_sa_entry_cleanup(sai, entry); + if (entry->se_inode) + iput(entry->se_inode); + + OBD_FREE(entry, entry->se_size); + cfs_atomic_dec(&sai->sai_cache_count); } +} - return rc; +static inline void +do_sai_entry_fini(struct ll_statahead_info *sai, struct ll_sa_entry *entry) +{ + struct ll_inode_info *lli = ll_i2info(sai->sai_inode); + + ll_sa_entry_unhash(sai, entry); + + spin_lock(&lli->lli_sa_lock); + entry->se_stat = SA_ENTRY_DEST; + if (likely(!ll_sa_entry_unlinked(entry))) + cfs_list_del_init(&entry->se_list); + spin_unlock(&lli->lli_sa_lock); + + ll_sa_entry_put(sai, entry); +} + +/* + * Delete it from sai_entries_stated list when fini. + */ +static void +ll_sa_entry_fini(struct ll_statahead_info *sai, struct ll_sa_entry *entry) +{ + struct ll_sa_entry *pos, *next; + + if (entry) + do_sai_entry_fini(sai, entry); + + /* drop old entry from sent list */ + cfs_list_for_each_entry_safe(pos, next, &sai->sai_entries_sent, + se_list) { + if (is_omitted_entry(sai, pos->se_index)) + do_sai_entry_fini(sai, pos); + else + break; + } + + /* drop old entry from stated list */ + cfs_list_for_each_entry_safe(pos, next, &sai->sai_entries_stated, + se_list) { + if (is_omitted_entry(sai, pos->se_index)) + do_sai_entry_fini(sai, pos); + else + break; + } +} + +/* + * Inside lli_sa_lock. + */ +static void +do_sai_entry_to_stated(struct ll_statahead_info *sai, + struct ll_sa_entry *entry, int rc) +{ + struct ll_sa_entry *se; + cfs_list_t *pos = &sai->sai_entries_stated; + + if (!ll_sa_entry_unlinked(entry)) + cfs_list_del_init(&entry->se_list); + + cfs_list_for_each_entry_reverse(se, &sai->sai_entries_stated, se_list) { + if (se->se_index < entry->se_index) { + pos = &se->se_list; + break; + } + } + + cfs_list_add(&entry->se_list, pos); + entry->se_stat = rc; +} + +/* + * Move entry to sai_entries_stated and sort with the index. + * \retval 1 -- entry to be destroyed. + * \retval 0 -- entry is inserted into stated list. + */ +static int +ll_sa_entry_to_stated(struct ll_statahead_info *sai, + struct ll_sa_entry *entry, int rc) +{ + struct ll_inode_info *lli = ll_i2info(sai->sai_inode); + int ret = 1; + + ll_sa_entry_cleanup(sai, entry); + + spin_lock(&lli->lli_sa_lock); + if (likely(entry->se_stat != SA_ENTRY_DEST)) { + do_sai_entry_to_stated(sai, entry, rc); + ret = 0; + } + spin_unlock(&lli->lli_sa_lock); + + return ret; +} + +/* + * Insert inode into the list of sai_entries_agl. + */ +static void ll_agl_add(struct ll_statahead_info *sai, + struct inode *inode, int index) +{ + struct ll_inode_info *child = ll_i2info(inode); + struct ll_inode_info *parent = ll_i2info(sai->sai_inode); + int added = 0; + + spin_lock(&child->lli_agl_lock); + if (child->lli_agl_index == 0) { + child->lli_agl_index = index; + spin_unlock(&child->lli_agl_lock); + + LASSERT(cfs_list_empty(&child->lli_agl_list)); + + igrab(inode); + spin_lock(&parent->lli_agl_lock); + if (agl_list_empty(sai)) + added = 1; + cfs_list_add_tail(&child->lli_agl_list, &sai->sai_entries_agl); + spin_unlock(&parent->lli_agl_lock); + } else { + spin_unlock(&child->lli_agl_lock); + } + + if (added > 0) + cfs_waitq_signal(&sai->sai_agl_thread.t_ctl_waitq); } -/* Check whether first entry was stated already or not. - * No need to hold lli_lock, for: - * (1) it is me that remove entry from the list (ll_sai_entry_put) - * (2) the statahead thread only add new entry to the list tail */ -static int ll_sai_entry_stated(struct ll_statahead_info *sai) +static struct ll_statahead_info *ll_sai_alloc(void) { - struct ll_sai_entry *entry; - int rc = 0; + struct ll_statahead_info *sai; + int i; ENTRY; - if (!list_empty(&sai->sai_entries)) { - entry = list_entry(sai->sai_entries.next, struct ll_sai_entry, - se_list); - rc = (entry->se_stat != SA_ENTRY_UNSTATED); + OBD_ALLOC_PTR(sai); + if (!sai) + RETURN(NULL); + + cfs_atomic_set(&sai->sai_refcount, 1); + + spin_lock(&sai_generation_lock); + sai->sai_generation = ++sai_generation; + if (unlikely(sai_generation == 0)) + sai->sai_generation = ++sai_generation; + spin_unlock(&sai_generation_lock); + + sai->sai_max = LL_SA_RPC_MIN; + sai->sai_index = 1; + cfs_waitq_init(&sai->sai_waitq); + cfs_waitq_init(&sai->sai_thread.t_ctl_waitq); + cfs_waitq_init(&sai->sai_agl_thread.t_ctl_waitq); + + CFS_INIT_LIST_HEAD(&sai->sai_entries_sent); + CFS_INIT_LIST_HEAD(&sai->sai_entries_received); + CFS_INIT_LIST_HEAD(&sai->sai_entries_stated); + CFS_INIT_LIST_HEAD(&sai->sai_entries_agl); + + for (i = 0; i < LL_SA_CACHE_SIZE; i++) { + CFS_INIT_LIST_HEAD(&sai->sai_cache[i]); + spin_lock_init(&sai->sai_cache_lock[i]); } + cfs_atomic_set(&sai->sai_cache_count, 0); - RETURN(rc); + RETURN(sai); } -static void ll_sai_entry_put(struct ll_statahead_info *sai) +static inline struct ll_statahead_info * +ll_sai_get(struct ll_statahead_info *sai) { - struct ll_inode_info *lli = ll_i2info(sai->sai_inode); - struct ll_sai_entry *entry; + cfs_atomic_inc(&sai->sai_refcount); + return sai; +} + +static void ll_sai_put(struct ll_statahead_info *sai) +{ + struct inode *inode = sai->sai_inode; + struct ll_inode_info *lli = ll_i2info(inode); ENTRY; - spin_lock(&lli->lli_lock); - if (!list_empty(&sai->sai_entries)) { - entry = list_entry(sai->sai_entries.next, - struct ll_sai_entry, se_list); - list_del(&entry->se_list); - OBD_FREE_PTR(entry); + if (cfs_atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_sa_lock)) { + struct ll_sa_entry *entry, *next; + + if (unlikely(cfs_atomic_read(&sai->sai_refcount) > 0)) { + /* It is race case, the interpret callback just hold + * a reference count */ + spin_unlock(&lli->lli_sa_lock); + RETURN_EXIT; + } + + LASSERT(lli->lli_opendir_key == NULL); + LASSERT(thread_is_stopped(&sai->sai_thread)); + LASSERT(thread_is_stopped(&sai->sai_agl_thread)); + + lli->lli_sai = NULL; + lli->lli_opendir_pid = 0; + spin_unlock(&lli->lli_sa_lock); + + if (sai->sai_sent > sai->sai_replied) + CDEBUG(D_READA,"statahead for dir "DFID" does not " + "finish: [sent:"LPU64"] [replied:"LPU64"]\n", + PFID(&lli->lli_fid), + sai->sai_sent, sai->sai_replied); + + cfs_list_for_each_entry_safe(entry, next, + &sai->sai_entries_sent, se_list) + do_sai_entry_fini(sai, entry); + + LASSERT(sa_received_empty(sai)); + + cfs_list_for_each_entry_safe(entry, next, + &sai->sai_entries_stated, se_list) + do_sai_entry_fini(sai, entry); + + LASSERT(cfs_atomic_read(&sai->sai_cache_count) == 0); + LASSERT(agl_list_empty(sai)); + + iput(inode); + OBD_FREE_PTR(sai); } - spin_unlock(&lli->lli_lock); EXIT; } -/* finish lookup/revalidate */ -static int ll_statahead_interpret(struct ptlrpc_request *req, - struct md_enqueue_info *minfo, - int rc) +/* Do NOT forget to drop inode refcount when into sai_entries_agl. */ +static void ll_agl_trigger(struct inode *inode, struct ll_statahead_info *sai) { - struct lookup_intent *it = &minfo->mi_it; - struct dentry *dentry = minfo->mi_dentry; - struct inode *dir = dentry->d_parent->d_inode; - struct ll_inode_info *lli = ll_i2info(dir); - struct ll_statahead_info *sai = NULL; + struct ll_inode_info *lli = ll_i2info(inode); + __u64 index = lli->lli_agl_index; + int rc; ENTRY; - CDEBUG(D_READA, "interpret statahead %.*s rc %d\n", - dentry->d_name.len, dentry->d_name.name, rc); + LASSERT(cfs_list_empty(&lli->lli_agl_list)); - spin_lock(&lli->lli_lock); - if (unlikely(lli->lli_sai == NULL || - lli->lli_sai->sai_generation != minfo->mi_generation)) { - spin_unlock(&lli->lli_lock); - GOTO(out_free, rc = -ESTALE); - } else { - sai = ll_sai_get(lli->lli_sai); - spin_unlock(&lli->lli_lock); + /* AGL maybe fall behind statahead with one entry */ + if (is_omitted_entry(sai, index + 1)) { + lli->lli_agl_index = 0; + iput(inode); + RETURN_EXIT; } - if (rc || dir == NULL) - GOTO(out, rc); + /* Someone is in glimpse (sync or async), do nothing. */ + rc = down_write_trylock(&lli->lli_glimpse_sem); + if (rc == 0) { + lli->lli_agl_index = 0; + iput(inode); + RETURN_EXIT; + } - if (dentry->d_inode == NULL) { - /* lookup */ - struct dentry *save = dentry; - struct it_cb_data icbd = { - .icbd_parent = dir, - .icbd_childp = &dentry - }; + /* + * Someone triggered glimpse within 1 sec before. + * 1) The former glimpse succeeded with glimpse lock granted by OST, and + * if the lock is still cached on client, AGL needs to do nothing. If + * it is cancelled by other client, AGL maybe cannot obtaion new lock + * for no glimpse callback triggered by AGL. + * 2) The former glimpse succeeded, but OST did not grant glimpse lock. + * Under such case, it is quite possible that the OST will not grant + * glimpse lock for AGL also. + * 3) The former glimpse failed, compared with other two cases, it is + * relative rare. AGL can ignore such case, and it will not muchly + * affect the performance. + */ + if (lli->lli_glimpse_time != 0 && + cfs_time_before(cfs_time_shift(-1), lli->lli_glimpse_time)) { + up_write(&lli->lli_glimpse_sem); + lli->lli_agl_index = 0; + iput(inode); + RETURN_EXIT; + } - LASSERT(fid_is_zero(&minfo->mi_data.op_fid2)); + CDEBUG(D_READA, "Handling (init) async glimpse: inode = " + DFID", idx = "LPU64"\n", PFID(&lli->lli_fid), index); - rc = ll_lookup_it_finish(req, it, &icbd); - if (!rc) - /* Here dentry->d_inode might be NULL, - * because the entry may have been removed before - * we start doing stat ahead. */ - ll_lookup_finish_locks(it, dentry); + cl_agl(inode); + lli->lli_agl_index = 0; + lli->lli_glimpse_time = cfs_time_current(); + up_write(&lli->lli_glimpse_sem); - if (dentry != save) - dput(save); - } else { - /* revalidate */ - struct mdt_body *body; + CDEBUG(D_READA, "Handled (init) async glimpse: inode= " + DFID", idx = "LPU64", rc = %d\n", + PFID(&lli->lli_fid), index, rc); + + iput(inode); + + EXIT; +} + +static void do_statahead_interpret(struct ll_statahead_info *sai, + struct ll_sa_entry *target) +{ + struct inode *dir = sai->sai_inode; + struct inode *child; + struct ll_inode_info *lli = ll_i2info(dir); + struct ll_sa_entry *entry; + struct md_enqueue_info *minfo; + struct lookup_intent *it; + struct ptlrpc_request *req; + struct mdt_body *body; + int rc = 0; + ENTRY; - body = lustre_msg_buf(req->rq_repmsg, DLM_REPLY_REC_OFF, - sizeof(*body)); - if (!lu_fid_eq(&minfo->mi_data.op_fid2, &body->fid1)) { - ll_unhash_aliases(dentry->d_inode); + spin_lock(&lli->lli_sa_lock); + if (target != NULL && target->se_req != NULL && + !cfs_list_empty(&target->se_list)) { + entry = target; + } else if (unlikely(sa_received_empty(sai))) { + spin_unlock(&lli->lli_sa_lock); + RETURN_EXIT; + } else { + entry = sa_first_received_entry(sai); + } + + cfs_atomic_inc(&entry->se_refcount); + cfs_list_del_init(&entry->se_list); + spin_unlock(&lli->lli_sa_lock); + + LASSERT(entry->se_handle != 0); + + minfo = entry->se_minfo; + it = &minfo->mi_it; + req = entry->se_req; + body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY); + if (body == NULL) + GOTO(out, rc = -EFAULT); + + child = entry->se_inode; + if (child == NULL) { + /* + * lookup. + */ + LASSERT(fid_is_zero(&minfo->mi_data.op_fid2)); + + /* XXX: No fid in reply, this is probaly cross-ref case. + * SA can't handle it yet. */ + if (body->valid & OBD_MD_MDS) GOTO(out, rc = -EAGAIN); + } else { + /* + * revalidate. + */ + /* unlinked and re-created with the same name */ + if (unlikely(!lu_fid_eq(&minfo->mi_data.op_fid2, &body->fid1))){ + entry->se_inode = NULL; + iput(child); + child = NULL; } + } - rc = ll_revalidate_it_finish(req, it, dentry); - if (rc) { - ll_unhash_aliases(dentry->d_inode); - GOTO(out, rc); - } + it->d.lustre.it_lock_handle = entry->se_handle; + rc = md_revalidate_lock(ll_i2mdexp(dir), it, ll_inode2fid(dir), NULL); + if (rc != 1) + GOTO(out, rc = -EAGAIN); - spin_lock(&dcache_lock); - lock_dentry(dentry); - __d_drop(dentry); -#ifdef DCACHE_LUSTRE_INVALID - dentry->d_flags &= ~DCACHE_LUSTRE_INVALID; -#endif - unlock_dentry(dentry); - d_rehash_cond(dentry, 0); - spin_unlock(&dcache_lock); + rc = ll_prep_inode(&child, req, dir->i_sb, it); + if (rc) + GOTO(out, rc); + + CDEBUG(D_DLMTRACE, "setting l_data to inode %p (%lu/%u)\n", + child, child->i_ino, child->i_generation); + ll_set_lock_data(ll_i2sbi(dir)->ll_md_exp, child, it, NULL); + + entry->se_inode = child; + + if (agl_should_run(sai, child)) + ll_agl_add(sai, child, entry->se_index); - ll_lookup_finish_locks(it, dentry); - } EXIT; out: - if (sai != NULL) { - int first; - - sai->sai_replied++; - spin_lock(&lli->lli_lock); - first = ll_sai_entry_set(sai, - (unsigned int)(long)minfo->mi_cbdata, - SA_ENTRY_STATED); - spin_unlock(&lli->lli_lock); - if (first == 1) - /* wake up the "ls -l" process only when the first entry - * returned. */ - cfs_waitq_signal(&sai->sai_waitq); - else if (first == 0) - CDEBUG(D_READA, "can't find sai entry for dir " - DFID" generation %u index %u\n", - PFID(&lli->lli_fid), - minfo->mi_generation, - (unsigned int)(long)minfo->mi_cbdata); + /* The "ll_sa_entry_to_stated()" will drop related ldlm ibits lock + * reference count by calling "ll_intent_drop_lock()" in spite of the + * above operations failed or not. Do not worry about calling + * "ll_intent_drop_lock()" more than once. */ + rc = ll_sa_entry_to_stated(sai, entry, rc < 0 ? rc : SA_ENTRY_SUCC); + if (rc == 0 && entry->se_index == sai->sai_index_wait && target == NULL) + cfs_waitq_signal(&sai->sai_waitq); + ll_sa_entry_put(sai, entry); +} - ll_sai_put(sai); +static int ll_statahead_interpret(struct ptlrpc_request *req, + struct md_enqueue_info *minfo, int rc) +{ + struct lookup_intent *it = &minfo->mi_it; + struct inode *dir = minfo->mi_dir; + struct ll_inode_info *lli = ll_i2info(dir); + struct ll_statahead_info *sai = NULL; + struct ll_sa_entry *entry; + int wakeup; + ENTRY; + + if (it_disposition(it, DISP_LOOKUP_NEG)) + rc = -ENOENT; + + spin_lock(&lli->lli_sa_lock); + /* stale entry */ + if (unlikely(lli->lli_sai == NULL || + lli->lli_sai->sai_generation != minfo->mi_generation)) { + spin_unlock(&lli->lli_sa_lock); + GOTO(out, rc = -ESTALE); + } else { + sai = ll_sai_get(lli->lli_sai); + if (unlikely(!thread_is_running(&sai->sai_thread))) { + sai->sai_replied++; + spin_unlock(&lli->lli_sa_lock); + GOTO(out, rc = -EBADFD); + } + + entry = ll_sa_entry_get_byindex(sai, minfo->mi_cbdata); + if (entry == NULL) { + sai->sai_replied++; + spin_unlock(&lli->lli_sa_lock); + GOTO(out, rc = -EIDRM); + } + + cfs_list_del_init(&entry->se_list); + if (rc != 0) { + sai->sai_replied++; + do_sai_entry_to_stated(sai, entry, rc); + spin_unlock(&lli->lli_sa_lock); + if (entry->se_index == sai->sai_index_wait) + cfs_waitq_signal(&sai->sai_waitq); + } else { + entry->se_minfo = minfo; + entry->se_req = ptlrpc_request_addref(req); + /* Release the async ibits lock ASAP to avoid deadlock + * when statahead thread tries to enqueue lock on parent + * for readpage and other tries to enqueue lock on child + * with parent's lock held, for example: unlink. */ + entry->se_handle = it->d.lustre.it_lock_handle; + ll_intent_drop_lock(it); + wakeup = sa_received_empty(sai); + cfs_list_add_tail(&entry->se_list, + &sai->sai_entries_received); + sai->sai_replied++; + spin_unlock(&lli->lli_sa_lock); + if (wakeup) + cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq); + } + ll_sa_entry_put(sai, entry); } -out_free: - ll_intent_release(it); - OBD_FREE_PTR(minfo); - dput(dentry); + EXIT; + +out: + if (rc != 0) { + ll_intent_release(it); + iput(dir); + OBD_FREE_PTR(minfo); + } + if (sai != NULL) + ll_sai_put(sai); return rc; } @@ -319,25 +797,29 @@ static void sa_args_fini(struct md_enqueue_info *minfo, struct ldlm_enqueue_info *einfo) { LASSERT(minfo && einfo); + iput(minfo->mi_dir); capa_put(minfo->mi_data.op_capa1); capa_put(minfo->mi_data.op_capa2); OBD_FREE_PTR(minfo); OBD_FREE_PTR(einfo); } -/* There is race condition between "capa_put" and "ll_statahead_interpret" for +/** + * There is race condition between "capa_put" and "ll_statahead_interpret" for * accessing "op_data.op_capa[1,2]" as following: * "capa_put" releases "op_data.op_capa[1,2]"'s reference count after calling * "md_intent_getattr_async". But "ll_statahead_interpret" maybe run first, and * fill "op_data.op_capa[1,2]" as POISON, then cause "capa_put" access invalid * "ocapa". So here reserve "op_data.op_capa[1,2]" in "pcapa" before calling - * "md_intent_getattr_async". */ -static int sa_args_init(struct inode *dir, struct dentry *dentry, - struct md_enqueue_info **pmi, + * "md_intent_getattr_async". + */ +static int sa_args_init(struct inode *dir, struct inode *child, + struct ll_sa_entry *entry, struct md_enqueue_info **pmi, struct ldlm_enqueue_info **pei, struct obd_capa **pcapa) { - struct ll_inode_info *lli = ll_i2info(dir); + struct qstr *qstr = &entry->se_qstr; + struct ll_inode_info *lli = ll_i2info(dir); struct md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; struct md_op_data *op_data; @@ -352,9 +834,8 @@ static int sa_args_init(struct inode *dir, struct dentry *dentry, return -ENOMEM; } - op_data = ll_prep_md_op_data(&minfo->mi_data, dir, dentry->d_inode, - dentry->d_name.name, dentry->d_name.len, - 0, LUSTRE_OPC_ANY, NULL); + op_data = ll_prep_md_op_data(&minfo->mi_data, dir, child, qstr->name, + qstr->len, 0, LUSTRE_OPC_ANY, NULL); if (IS_ERR(op_data)) { OBD_FREE_PTR(einfo); OBD_FREE_PTR(minfo); @@ -362,10 +843,10 @@ static int sa_args_init(struct inode *dir, struct dentry *dentry, } minfo->mi_it.it_op = IT_GETATTR; - minfo->mi_dentry = dentry; + minfo->mi_dir = igrab(dir); minfo->mi_cb = ll_statahead_interpret; minfo->mi_generation = lli->lli_sai->sai_generation; - minfo->mi_cbdata = (void *)(long)lli->lli_sai->sai_index; + minfo->mi_cbdata = entry->se_index; einfo->ei_type = LDLM_IBITS; einfo->ei_mode = it_to_lock_mode(&minfo->mi_it); @@ -382,8 +863,7 @@ static int sa_args_init(struct inode *dir, struct dentry *dentry, return 0; } -/* similar to ll_lookup_it(). */ -static int do_sa_lookup(struct inode *dir, struct dentry *dentry) +static int do_sa_lookup(struct inode *dir, struct ll_sa_entry *entry) { struct md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; @@ -391,7 +871,7 @@ static int do_sa_lookup(struct inode *dir, struct dentry *dentry) int rc; ENTRY; - rc = sa_args_init(dir, dentry, &minfo, &einfo, capas); + rc = sa_args_init(dir, NULL, entry, &minfo, &einfo, capas); if (rc) RETURN(rc); @@ -406,181 +886,236 @@ static int do_sa_lookup(struct inode *dir, struct dentry *dentry) RETURN(rc); } -/* similar to ll_revalidate_it(). - * return value: - * 1 -- dentry valid - * 0 -- will send stat-ahead request - * others -- prepare stat-ahead request failed */ -static int do_sa_revalidate(struct dentry *dentry) +/** + * similar to ll_revalidate_it(). + * \retval 1 -- dentry valid + * \retval 0 -- will send stat-ahead request + * \retval others -- prepare stat-ahead request failed + */ +static int do_sa_revalidate(struct inode *dir, struct ll_sa_entry *entry, + struct dentry *dentry) { struct inode *inode = dentry->d_inode; - struct inode *dir = dentry->d_parent->d_inode; - struct lookup_intent it = { .it_op = IT_GETATTR }; + struct lookup_intent it = { .it_op = IT_GETATTR, + .d.lustre.it_lock_handle = 0 }; struct md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; struct obd_capa *capas[2]; int rc; ENTRY; - if (inode == NULL) + if (unlikely(inode == NULL)) RETURN(1); if (d_mountpoint(dentry)) RETURN(1); - if (dentry == dentry->d_sb->s_root) + if (unlikely(dentry == dentry->d_sb->s_root)) RETURN(1); - rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode)); + entry->se_inode = igrab(inode); + rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode),NULL); if (rc == 1) { + entry->se_handle = it.d.lustre.it_lock_handle; ll_intent_release(&it); RETURN(1); } - rc = sa_args_init(dir, dentry, &minfo, &einfo, capas); - if (rc) + rc = sa_args_init(dir, inode, entry, &minfo, &einfo, capas); + if (rc) { + entry->se_inode = NULL; + iput(inode); RETURN(rc); + } rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo); if (!rc) { capa_put(capas[0]); capa_put(capas[1]); } else { + entry->se_inode = NULL; + iput(inode); sa_args_fini(minfo, einfo); } RETURN(rc); } -static inline void ll_name2qstr(struct qstr *this, const char *name, int namelen) -{ - unsigned long hash = init_name_hash(); - unsigned int c; - - this->name = name; - this->len = namelen; - for (; namelen > 0; namelen--, name++) { - c = *(const unsigned char *)name; - hash = partial_name_hash(c, hash); - } - this->hash = end_name_hash(hash); -} - -static int ll_statahead_one(struct dentry *parent, const char* entry_name, - int entry_name_len) +static void ll_statahead_one(struct dentry *parent, const char* entry_name, + int entry_name_len) { - struct inode *dir = parent->d_inode; - struct ll_inode_info *lli = ll_i2info(dir); - struct ll_statahead_info *sai = lli->lli_sai; - struct qstr name; - struct dentry *dentry; - struct ll_sai_entry *se; + struct inode *dir = parent->d_inode; + struct ll_inode_info *lli = ll_i2info(dir); + struct ll_statahead_info *sai = lli->lli_sai; + struct dentry *dentry = NULL; + struct ll_sa_entry *entry; int rc; + int rc1; ENTRY; -#ifdef DCACHE_LUSTRE_INVALID - if (parent->d_flags & DCACHE_LUSTRE_INVALID) { -#else - if (d_unhashed(parent)) { -#endif - CDEBUG(D_READA, "parent dentry@%p %.*s is " - "invalid, skip statahead\n", - parent, parent->d_name.len, parent->d_name.name); - RETURN(-EINVAL); - } - - se = ll_sai_entry_get(sai, sai->sai_index, SA_ENTRY_UNSTATED); - if (IS_ERR(se)) - RETURN(PTR_ERR(se)); + entry = ll_sa_entry_alloc(sai, sai->sai_index, entry_name, + entry_name_len); + if (IS_ERR(entry)) + RETURN_EXIT; - ll_name2qstr(&name, entry_name, entry_name_len); - dentry = d_lookup(parent, &name); + dentry = d_lookup(parent, &entry->se_qstr); if (!dentry) { - dentry = d_alloc(parent, &name); - if (dentry) { - rc = do_sa_lookup(dir, dentry); - if (rc) - dput(dentry); - } else { - GOTO(out, rc = -ENOMEM); - } + rc = do_sa_lookup(dir, entry); } else { - rc = do_sa_revalidate(dentry); - if (rc) - dput(dentry); + rc = do_sa_revalidate(dir, entry, dentry); + if (rc == 1 && agl_should_run(sai, dentry->d_inode)) + ll_agl_add(sai, dentry->d_inode, entry->se_index); } - EXIT; + if (dentry != NULL) + dput(dentry); -out: if (rc) { - CDEBUG(D_READA, "set sai entry %p index %u stat %d rc %d\n", - se, se->se_index, se->se_stat, rc); - se->se_stat = rc; - cfs_waitq_signal(&sai->sai_waitq); + rc1 = ll_sa_entry_to_stated(sai, entry, + rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC); + if (rc1 == 0 && entry->se_index == sai->sai_index_wait) + cfs_waitq_signal(&sai->sai_waitq); } else { sai->sai_sent++; } sai->sai_index++; - return rc; -} + /* drop one refcount on entry by ll_sa_entry_alloc */ + ll_sa_entry_put(sai, entry); -static inline int sa_check_stop(struct ll_statahead_info *sai) -{ - return !!(sai->sai_thread.t_flags & SVC_STOPPING); + EXIT; } -static inline int sa_not_full(struct ll_statahead_info *sai) +static int ll_agl_thread(void *arg) { - return sai->sai_index < sai->sai_hit + sai->sai_miss + sai->sai_max; + struct dentry *parent = (struct dentry *)arg; + struct inode *dir = parent->d_inode; + struct ll_inode_info *plli = ll_i2info(dir); + struct ll_inode_info *clli; + struct ll_sb_info *sbi = ll_i2sbi(dir); + struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai); + struct ptlrpc_thread *thread = &sai->sai_agl_thread; + struct l_wait_info lwi = { 0 }; + ENTRY; + + { + char pname[16]; + snprintf(pname, 15, "ll_agl_%u", plli->lli_opendir_pid); + cfs_daemonize(pname); + } + + CDEBUG(D_READA, "agl thread started: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); + + atomic_inc(&sbi->ll_agl_total); + spin_lock(&plli->lli_agl_lock); + sai->sai_agl_valid = 1; + thread_set_flags(thread, SVC_RUNNING); + spin_unlock(&plli->lli_agl_lock); + cfs_waitq_signal(&thread->t_ctl_waitq); + + while (1) { + l_wait_event(thread->t_ctl_waitq, + !agl_list_empty(sai) || + !thread_is_running(thread), + &lwi); + + if (!thread_is_running(thread)) + break; + + spin_lock(&plli->lli_agl_lock); + /* The statahead thread maybe help to process AGL entries, + * so check whether list empty again. */ + if (!agl_list_empty(sai)) { + clli = agl_first_entry(sai); + cfs_list_del_init(&clli->lli_agl_list); + spin_unlock(&plli->lli_agl_lock); + ll_agl_trigger(&clli->lli_vfs_inode, sai); + } else { + spin_unlock(&plli->lli_agl_lock); + } + } + + spin_lock(&plli->lli_agl_lock); + sai->sai_agl_valid = 0; + while (!agl_list_empty(sai)) { + clli = agl_first_entry(sai); + cfs_list_del_init(&clli->lli_agl_list); + spin_unlock(&plli->lli_agl_lock); + clli->lli_agl_index = 0; + iput(&clli->lli_vfs_inode); + spin_lock(&plli->lli_agl_lock); + } + thread_set_flags(thread, SVC_STOPPED); + spin_unlock(&plli->lli_agl_lock); + cfs_waitq_signal(&thread->t_ctl_waitq); + ll_sai_put(sai); + CDEBUG(D_READA, "agl thread stopped: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); + RETURN(0); } -/* (1) hit ratio less than 80% - * or - * (2) consecutive miss more than 8 */ -static inline int sa_low_hit(struct ll_statahead_info *sai) +static void ll_start_agl(struct dentry *parent, struct ll_statahead_info *sai) { - return ((sai->sai_hit < 4 * sai->sai_miss && sai->sai_hit > 7) || - (sai->sai_consecutive_miss > 8)); -} + struct ptlrpc_thread *thread = &sai->sai_agl_thread; + struct l_wait_info lwi = { 0 }; + int rc; + ENTRY; -struct ll_sa_thread_args { - struct dentry *sta_parent; - pid_t sta_pid; -}; + CDEBUG(D_READA, "start agl thread: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); + + rc = cfs_create_thread(ll_agl_thread, parent, 0); + if (rc < 0) { + CERROR("can't start ll_agl thread, rc: %d\n", rc); + thread_set_flags(thread, SVC_STOPPED); + RETURN_EXIT; + } + + l_wait_event(thread->t_ctl_waitq, + thread_is_running(thread) || thread_is_stopped(thread), + &lwi); + EXIT; +} static int ll_statahead_thread(void *arg) { - struct ll_sa_thread_args *sta = arg; - struct dentry *parent = dget(sta->sta_parent); - struct inode *dir = parent->d_inode; - struct ll_inode_info *lli = ll_i2info(dir); - struct ll_sb_info *sbi = ll_i2sbi(dir); - struct ll_statahead_info *sai = ll_sai_get(lli->lli_sai); + struct dentry *parent = (struct dentry *)arg; + struct inode *dir = parent->d_inode; + struct ll_inode_info *plli = ll_i2info(dir); + struct ll_inode_info *clli; + struct ll_sb_info *sbi = ll_i2sbi(dir); + struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai); struct ptlrpc_thread *thread = &sai->sai_thread; + struct ptlrpc_thread *agl_thread = &sai->sai_agl_thread; struct page *page; - __u64 pos = 0; - int first = 0; - int rc = 0; + __u64 pos = 0; + int first = 0; + int rc = 0; struct ll_dir_chain chain; + struct l_wait_info lwi = { 0 }; ENTRY; { char pname[16]; - snprintf(pname, 15, "ll_sa_%u", sta->sta_pid); + snprintf(pname, 15, "ll_sa_%u", plli->lli_opendir_pid); cfs_daemonize(pname); } - sbi->ll_sa_total++; - spin_lock(&lli->lli_lock); - thread->t_flags = SVC_RUNNING; - spin_unlock(&lli->lli_lock); - cfs_waitq_signal(&thread->t_ctl_waitq); - CDEBUG(D_READA, "start doing statahead for %s\n", parent->d_name.name); + CDEBUG(D_READA, "statahead thread started: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); - ll_dir_chain_init(&chain); - page = ll_get_dir_page(dir, pos, 0, &chain); + if (sbi->ll_flags & LL_SBI_AGL_ENABLED) + ll_start_agl(parent, sai); + + atomic_inc(&sbi->ll_sa_total); + spin_lock(&plli->lli_sa_lock); + thread_set_flags(thread, SVC_RUNNING); + spin_unlock(&plli->lli_sa_lock); + cfs_waitq_signal(&thread->t_ctl_waitq); + + ll_dir_chain_init(&chain); + page = ll_get_dir_page(dir, pos, &chain); while (1) { struct lu_dirpage *dp; @@ -588,175 +1123,329 @@ static int ll_statahead_thread(void *arg) if (IS_ERR(page)) { rc = PTR_ERR(page); - CERROR("error reading dir "DFID" at %llu/%u: rc %d\n", - PFID(ll_inode2fid(dir)), pos, - sai->sai_index, rc); - break; + CDEBUG(D_READA, "error reading dir "DFID" at "LPU64 + "/"LPU64": [rc %d] [parent %u]\n", + PFID(ll_inode2fid(dir)), pos, sai->sai_index, + rc, plli->lli_opendir_pid); + GOTO(out, rc); } dp = page_address(page); for (ent = lu_dirent_start(dp); ent != NULL; ent = lu_dirent_next(ent)) { - struct l_wait_info lwi = { 0 }; - char *name = ent->lde_name; - int namelen = le16_to_cpu(ent->lde_namelen); + __u64 hash; + int namelen; + char *name; + + hash = le64_to_cpu(ent->lde_hash); + if (unlikely(hash < pos)) + /* + * Skip until we find target hash value. + */ + continue; - if (namelen == 0) - /* Skip dummy record. */ + namelen = le16_to_cpu(ent->lde_namelen); + if (unlikely(namelen == 0)) + /* + * Skip dummy record. + */ continue; + name = ent->lde_name; if (name[0] == '.') { if (namelen == 1) { - /* skip . */ + /* + * skip "." + */ continue; } else if (name[1] == '.' && namelen == 2) { - /* skip .. */ + /* + * skip ".." + */ continue; } else if (!sai->sai_ls_all) { - /* skip hidden files */ + /* + * skip hidden files. + */ sai->sai_skip_hidden++; continue; } } - /* don't stat-ahead first entry */ - if (unlikely(!first)) { - first++; + /* + * don't stat-ahead first entry. + */ + if (unlikely(++first == 1)) continue; - } +keep_it: l_wait_event(thread->t_ctl_waitq, - sa_check_stop(sai) || sa_not_full(sai), + !sa_sent_full(sai) || + !sa_received_empty(sai) || + !agl_list_empty(sai) || + !thread_is_running(thread), &lwi); - if (unlikely(sa_check_stop(sai))) { - ll_put_page(page); - GOTO(out, rc); +interpret_it: + while (!sa_received_empty(sai)) + do_statahead_interpret(sai, NULL); + + if (unlikely(!thread_is_running(thread))) { + ll_release_page(page, 0); + GOTO(out, rc = 0); } - rc = ll_statahead_one(parent, name, namelen); - if (rc < 0) { - ll_put_page(page); - GOTO(out, rc); + /* If no window for metadata statahead, but there are + * some AGL entries to be triggered, then try to help + * to process the AGL entries. */ + if (sa_sent_full(sai)) { + spin_lock(&plli->lli_agl_lock); + while (!agl_list_empty(sai)) { + clli = agl_first_entry(sai); + cfs_list_del_init(&clli->lli_agl_list); + spin_unlock(&plli->lli_agl_lock); + ll_agl_trigger(&clli->lli_vfs_inode, + sai); + + if (!sa_received_empty(sai)) + goto interpret_it; + + if (unlikely( + !thread_is_running(thread))) { + ll_release_page(page, 0); + GOTO(out, rc = 0); + } + + if (!sa_sent_full(sai)) + goto do_it; + + spin_lock(&plli->lli_agl_lock); + } + spin_unlock(&plli->lli_agl_lock); + + goto keep_it; } + +do_it: + ll_statahead_one(parent, name, namelen); } pos = le64_to_cpu(dp->ldp_hash_end); - ll_put_page(page); - if (pos == DIR_END_OFF) { - /* End of directory reached. */ - break; - } else if (1 /* chain is exhausted*/) { - /* Normal case: continue to the next page. */ - page = ll_get_dir_page(dir, pos, 1, &chain); + if (pos == MDS_DIR_END_OFF) { + /* + * End of directory reached. + */ + ll_release_page(page, 0); + while (1) { + l_wait_event(thread->t_ctl_waitq, + !sa_received_empty(sai) || + sai->sai_sent == sai->sai_replied|| + !thread_is_running(thread), + &lwi); + + while (!sa_received_empty(sai)) + do_statahead_interpret(sai, NULL); + + if (unlikely(!thread_is_running(thread))) + GOTO(out, rc = 0); + + if (sai->sai_sent == sai->sai_replied && + sa_received_empty(sai)) + break; + } + + spin_lock(&plli->lli_agl_lock); + while (!agl_list_empty(sai) && + thread_is_running(thread)) { + clli = agl_first_entry(sai); + cfs_list_del_init(&clli->lli_agl_list); + spin_unlock(&plli->lli_agl_lock); + ll_agl_trigger(&clli->lli_vfs_inode, sai); + spin_lock(&plli->lli_agl_lock); + } + spin_unlock(&plli->lli_agl_lock); + + GOTO(out, rc = 0); + } else if (1) { + /* + * chain is exhausted. + * Normal case: continue to the next page. + */ + ll_release_page(page, le32_to_cpu(dp->ldp_flags) & + LDF_COLLIDE); + sai->sai_in_readpage = 1; + page = ll_get_dir_page(dir, pos, &chain); + sai->sai_in_readpage = 0; } else { - /* go into overflow page. */ + LASSERT(le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE); + ll_release_page(page, 1); + /* + * go into overflow page. + */ } } EXIT; out: + if (sai->sai_agl_valid) { + spin_lock(&plli->lli_agl_lock); + thread_set_flags(agl_thread, SVC_STOPPING); + spin_unlock(&plli->lli_agl_lock); + cfs_waitq_signal(&agl_thread->t_ctl_waitq); + + CDEBUG(D_READA, "stop agl thread: [pid %d]\n", + cfs_curproc_pid()); + l_wait_event(agl_thread->t_ctl_waitq, + thread_is_stopped(agl_thread), + &lwi); + } else { + /* Set agl_thread flags anyway. */ + thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED); + } ll_dir_chain_fini(&chain); - spin_lock(&lli->lli_lock); - thread->t_flags = SVC_STOPPED; - spin_unlock(&lli->lli_lock); + spin_lock(&plli->lli_sa_lock); + if (!sa_received_empty(sai)) { + thread_set_flags(thread, SVC_STOPPING); + spin_unlock(&plli->lli_sa_lock); + + /* To release the resources held by received entries. */ + while (!sa_received_empty(sai)) + do_statahead_interpret(sai, NULL); + + spin_lock(&plli->lli_sa_lock); + } + thread_set_flags(thread, SVC_STOPPED); + spin_unlock(&plli->lli_sa_lock); cfs_waitq_signal(&sai->sai_waitq); cfs_waitq_signal(&thread->t_ctl_waitq); ll_sai_put(sai); dput(parent); - CDEBUG(D_READA, "statahead thread stopped, pid %d\n", - cfs_curproc_pid()); + CDEBUG(D_READA, "statahead thread stopped: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); return rc; } -/* called in ll_file_release() */ -void ll_stop_statahead(struct inode *inode, void *key) +/** + * called in ll_file_release(). + */ +void ll_stop_statahead(struct inode *dir, void *key) { - struct ll_inode_info *lli = ll_i2info(inode); - struct ptlrpc_thread *thread; + struct ll_inode_info *lli = ll_i2info(dir); - spin_lock(&lli->lli_lock); - if (lli->lli_opendir_pid == 0 || - unlikely(lli->lli_opendir_key != key)) { - spin_unlock(&lli->lli_lock); + if (unlikely(key == NULL)) + return; + + spin_lock(&lli->lli_sa_lock); + if (lli->lli_opendir_key != key || lli->lli_opendir_pid == 0) { + spin_unlock(&lli->lli_sa_lock); return; } lli->lli_opendir_key = NULL; - lli->lli_opendir_pid = 0; if (lli->lli_sai) { struct l_wait_info lwi = { 0 }; - - thread = &lli->lli_sai->sai_thread; - if (!(thread->t_flags & SVC_STOPPED)) { - thread->t_flags = SVC_STOPPING; - spin_unlock(&lli->lli_lock); - cfs_waitq_signal(&thread->t_ctl_waitq); - - CDEBUG(D_READA, "stopping statahead thread, pid %d\n", - cfs_curproc_pid()); - l_wait_event(thread->t_ctl_waitq, - thread->t_flags & SVC_STOPPED, - &lwi); - } else { - spin_unlock(&lli->lli_lock); - } - - /* Put the ref which was held when first statahead_enter. - * It maybe not the last ref for some statahead requests - * maybe inflight. */ - ll_sai_put(lli->lli_sai); - return; - } - spin_unlock(&lli->lli_lock); + struct ptlrpc_thread *thread = &lli->lli_sai->sai_thread; + + if (!thread_is_stopped(thread)) { + thread_set_flags(thread, SVC_STOPPING); + spin_unlock(&lli->lli_sa_lock); + cfs_waitq_signal(&thread->t_ctl_waitq); + + CDEBUG(D_READA, "stop statahead thread: [pid %d]\n", + cfs_curproc_pid()); + l_wait_event(thread->t_ctl_waitq, + thread_is_stopped(thread), + &lwi); + } else { + spin_unlock(&lli->lli_sa_lock); + } + + /* + * Put the ref which was held when first statahead_enter. + * It maybe not the last ref for some statahead requests + * maybe inflight. + */ + ll_sai_put(lli->lli_sai); + } else { + lli->lli_opendir_pid = 0; + spin_unlock(&lli->lli_sa_lock); + } } enum { - LS_NONE_FIRST_DE = 0, /* not first dirent, or is "." */ - LS_FIRST_DE, /* the first non-hidden dirent */ - LS_FIRST_DOT_DE /* the first hidden dirent, that is ".xxx" */ + /** + * not first dirent, or is "." + */ + LS_NONE_FIRST_DE = 0, + /** + * the first non-hidden dirent + */ + LS_FIRST_DE, + /** + * the first hidden dirent, that is "." + */ + LS_FIRST_DOT_DE }; static int is_first_dirent(struct inode *dir, struct dentry *dentry) { - struct ll_dir_chain chain; - struct qstr *target = &dentry->d_name; - struct page *page; - __u64 pos = 0; - int dot_de; - int rc = LS_NONE_FIRST_DE; + struct ll_dir_chain chain; + struct qstr *target = &dentry->d_name; + struct page *page; + __u64 pos = 0; + int dot_de; + int rc = LS_NONE_FIRST_DE; ENTRY; ll_dir_chain_init(&chain); - page = ll_get_dir_page(dir, pos, 0, &chain); + page = ll_get_dir_page(dir, pos, &chain); while (1) { struct lu_dirpage *dp; struct lu_dirent *ent; if (IS_ERR(page)) { + struct ll_inode_info *lli = ll_i2info(dir); + rc = PTR_ERR(page); - CERROR("error reading dir "DFID" at %llu: rc %d\n", - PFID(ll_inode2fid(dir)), pos, rc); + CERROR("error reading dir "DFID" at "LPU64": " + "[rc %d] [parent %u]\n", + PFID(ll_inode2fid(dir)), pos, + rc, lli->lli_opendir_pid); break; } dp = page_address(page); for (ent = lu_dirent_start(dp); ent != NULL; ent = lu_dirent_next(ent)) { - char *name = ent->lde_name; - int namelen = le16_to_cpu(ent->lde_namelen); + __u64 hash; + int namelen; + char *name; + + hash = le64_to_cpu(ent->lde_hash); + /* The ll_get_dir_page() can return any page containing + * the given hash which may be not the start hash. */ + if (unlikely(hash < pos)) + continue; - if (namelen == 0) - /* Skip dummy record. */ + namelen = le16_to_cpu(ent->lde_namelen); + if (unlikely(namelen == 0)) + /* + * skip dummy record. + */ continue; + name = ent->lde_name; if (name[0] == '.') { if (namelen == 1) - /* skip . */ + /* + * skip "." + */ continue; else if (name[1] == '.' && namelen == 2) - /* skip .. */ + /* + * skip ".." + */ continue; else dot_de = 1; @@ -771,24 +1460,38 @@ static int is_first_dirent(struct inode *dir, struct dentry *dentry) continue; } - if (target->len == namelen && - !strncmp(target->name, name, target->len)) - rc = LS_FIRST_DE + dot_de; - else + if (target->len != namelen || + memcmp(target->name, name, namelen) != 0) rc = LS_NONE_FIRST_DE; - ll_put_page(page); + else if (!dot_de) + rc = LS_FIRST_DE; + else + rc = LS_FIRST_DOT_DE; + + ll_release_page(page, 0); GOTO(out, rc); } pos = le64_to_cpu(dp->ldp_hash_end); - ll_put_page(page); - if (pos == DIR_END_OFF) { - /* End of directory reached. */ + if (pos == MDS_DIR_END_OFF) { + /* + * End of directory reached. + */ + ll_release_page(page, 0); break; - } else if (1 /* chain is exhausted*/) { - /* Normal case: continue to the next page. */ - page = ll_get_dir_page(dir, pos, 1, &chain); + } else if (1) { + /* + * chain is exhausted + * Normal case: continue to the next page. + */ + ll_release_page(page, le32_to_cpu(dp->ldp_flags) & + LDF_COLLIDE); + page = ll_get_dir_page(dir, pos, &chain); } else { - /* go into overflow page. */ + /* + * go into overflow page. + */ + LASSERT(le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE); + ll_release_page(page, 1); } } EXIT; @@ -798,166 +1501,243 @@ out: return rc; } -/* Start statahead thread if this is the first dir entry. +static void +ll_sai_unplug(struct ll_statahead_info *sai, struct ll_sa_entry *entry) +{ + struct ptlrpc_thread *thread = &sai->sai_thread; + struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode); + int hit; + ENTRY; + + if (entry != NULL && entry->se_stat == SA_ENTRY_SUCC) + hit = 1; + else + hit = 0; + + ll_sa_entry_fini(sai, entry); + if (hit) { + sai->sai_hit++; + sai->sai_consecutive_miss = 0; + sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max); + } else { + struct ll_inode_info *lli = ll_i2info(sai->sai_inode); + + sai->sai_miss++; + sai->sai_consecutive_miss++; + if (sa_low_hit(sai) && thread_is_running(thread)) { + atomic_inc(&sbi->ll_sa_wrong); + CDEBUG(D_READA, "Statahead for dir "DFID" hit " + "ratio too low: hit/miss "LPU64"/"LPU64 + ", sent/replied "LPU64"/"LPU64", stopping " + "statahead thread: pid %d\n", + PFID(&lli->lli_fid), sai->sai_hit, + sai->sai_miss, sai->sai_sent, + sai->sai_replied, cfs_curproc_pid()); + spin_lock(&lli->lli_sa_lock); + if (!thread_is_stopped(thread)) + thread_set_flags(thread, SVC_STOPPING); + spin_unlock(&lli->lli_sa_lock); + } + } + + if (!thread_is_stopped(thread)) + cfs_waitq_signal(&thread->t_ctl_waitq); + + EXIT; +} + +/** + * Start statahead thread if this is the first dir entry. * Otherwise if a thread is started already, wait it until it is ahead of me. - * Return value: - * 0 -- stat ahead thread process such dentry, for lookup, it miss - * 1 -- stat ahead thread process such dentry, for lookup, it hit - * -EEXIST -- stat ahead thread started, and this is the first dentry - * -EBADFD -- statahead thread exit and not dentry available - * others -- error */ -int do_statahead_enter(struct inode *dir, struct dentry **dentryp, int lookup) -{ - struct ll_sb_info *sbi = ll_i2sbi(dir); - struct ll_inode_info *lli = ll_i2info(dir); - struct ll_statahead_info *sai = lli->lli_sai; - struct ll_sa_thread_args sta; - struct l_wait_info lwi = { 0 }; - int rc; + * \retval 1 -- find entry with lock in cache, the caller needs to do + * nothing. + * \retval 0 -- find entry in cache, but without lock, the caller needs + * refresh from MDS. + * \retval others -- the caller need to process as non-statahead. + */ +int do_statahead_enter(struct inode *dir, struct dentry **dentryp, + int only_unplug) +{ + struct ll_inode_info *lli = ll_i2info(dir); + struct ll_statahead_info *sai = lli->lli_sai; + struct dentry *parent; + struct ll_sa_entry *entry; + struct ptlrpc_thread *thread; + struct l_wait_info lwi = { 0 }; + int rc = 0; ENTRY; LASSERT(lli->lli_opendir_pid == cfs_curproc_pid()); if (sai) { - if (unlikely(sai->sai_thread.t_flags & SVC_STOPPED && - list_empty(&sai->sai_entries))) - RETURN(-EBADFD); + thread = &sai->sai_thread; + if (unlikely(thread_is_stopped(thread) && + cfs_list_empty(&sai->sai_entries_stated))) { + /* to release resource */ + ll_stop_statahead(dir, lli->lli_opendir_key); + RETURN(-EAGAIN); + } if ((*dentryp)->d_name.name[0] == '.') { - if (likely(sai->sai_ls_all || - sai->sai_miss_hidden >= sai->sai_skip_hidden)) { - /* Hidden dentry is the first one, or statahead + if (sai->sai_ls_all || + sai->sai_miss_hidden >= sai->sai_skip_hidden) { + /* + * Hidden dentry is the first one, or statahead * thread does not skip so many hidden dentries - * before "sai_ls_all" enabled as below. */ + * before "sai_ls_all" enabled as below. + */ } else { if (!sai->sai_ls_all) - /* It maybe because hidden dentry is not + /* + * It maybe because hidden dentry is not * the first one, "sai_ls_all" was not * set, then "ls -al" missed. Enable - * "sai_ls_all" for such case. */ + * "sai_ls_all" for such case. + */ sai->sai_ls_all = 1; - /* Such "getattr" has been skipped before - * "sai_ls_all" enabled as above. */ + /* + * Such "getattr" has been skipped before + * "sai_ls_all" enabled as above. + */ sai->sai_miss_hidden++; - RETURN(-ENOENT); + RETURN(-EAGAIN); } } - if (ll_sai_entry_stated(sai)) { - sbi->ll_sa_cached++; - } else { - sbi->ll_sa_blocked++; - /* thread started already, avoid double-stat */ - l_wait_event(sai->sai_waitq, - ll_sai_entry_stated(sai) || - sai->sai_thread.t_flags & SVC_STOPPED, - &lwi); + entry = ll_sa_entry_get_byname(sai, &(*dentryp)->d_name); + if (entry == NULL || only_unplug) { + ll_sai_unplug(sai, entry); + RETURN(entry ? 1 : -EAGAIN); } - if (lookup) { - struct dentry *result; + while (!ll_sa_entry_stated(entry) && + sai->sai_in_readpage && + !sa_received_empty(sai)) + do_statahead_interpret(sai, entry); + + if (!ll_sa_entry_stated(entry)) { + sai->sai_index_wait = entry->se_index; + lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL, + LWI_ON_SIGNAL_NOOP, NULL); + rc = l_wait_event(sai->sai_waitq, + ll_sa_entry_stated(entry) || + thread_is_stopped(thread), + &lwi); + if (rc < 0) { + ll_sai_unplug(sai, entry); + RETURN(-EAGAIN); + } + } - result = d_lookup((*dentryp)->d_parent, - &(*dentryp)->d_name); - if (result) { - LASSERT(result != *dentryp); - dput(*dentryp); - *dentryp = result; - RETURN(1); + if (entry->se_stat == SA_ENTRY_SUCC && + entry->se_inode != NULL) { + struct inode *inode = entry->se_inode; + struct lookup_intent it = { .it_op = IT_GETATTR, + .d.lustre.it_lock_handle = + entry->se_handle }; + __u64 bits; + + rc = md_revalidate_lock(ll_i2mdexp(dir), &it, + ll_inode2fid(inode), &bits); + if (rc == 1) { + if ((*dentryp)->d_inode == NULL) { + *dentryp = ll_splice_alias(inode, + *dentryp); + } else if ((*dentryp)->d_inode != inode) { + /* revalidate, but inode is recreated */ + CDEBUG(D_READA, + "stale dentry %.*s inode %lu/%u, " + "statahead inode %lu/%u\n", + (*dentryp)->d_name.len, + (*dentryp)->d_name.name, + (*dentryp)->d_inode->i_ino, + (*dentryp)->d_inode->i_generation, + inode->i_ino, + inode->i_generation); + ll_sai_unplug(sai, entry); + RETURN(-ESTALE); + } else { + iput(inode); + } + entry->se_inode = NULL; + + if ((bits & MDS_INODELOCK_LOOKUP) && + d_lustre_invalid(*dentryp)) + d_lustre_revalidate(*dentryp); + ll_intent_release(&it); } } - /* do nothing for revalidate */ - RETURN(0); - } - /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */ - LASSERT(lli->lli_sai == NULL); + ll_sai_unplug(sai, entry); + RETURN(rc); + } + /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */ rc = is_first_dirent(dir, *dentryp); - if (rc == LS_NONE_FIRST_DE) { - /* It is not "ls -{a}l" operation, no need statahead for it */ - spin_lock(&lli->lli_lock); - lli->lli_opendir_key = NULL; - lli->lli_opendir_pid = 0; - spin_unlock(&lli->lli_lock); - RETURN(-EBADF); - } + if (rc == LS_NONE_FIRST_DE) + /* It is not "ls -{a}l" operation, no need statahead for it. */ + GOTO(out, rc = -EAGAIN); sai = ll_sai_alloc(); if (sai == NULL) - RETURN(-ENOMEM); + GOTO(out, rc = -ENOMEM); - sai->sai_inode = igrab(dir); sai->sai_ls_all = (rc == LS_FIRST_DOT_DE); + sai->sai_inode = igrab(dir); + if (unlikely(sai->sai_inode == NULL)) { + CWARN("Do not start stat ahead on dying inode "DFID"\n", + PFID(&lli->lli_fid)); + GOTO(out, rc = -ESTALE); + } + + /* get parent reference count here, and put it in ll_statahead_thread */ + parent = dget((*dentryp)->d_parent); + if (unlikely(sai->sai_inode != parent->d_inode)) { + struct ll_inode_info *nlli = ll_i2info(parent->d_inode); + + CWARN("Race condition, someone changed %.*s just now: " + "old parent "DFID", new parent "DFID"\n", + (*dentryp)->d_name.len, (*dentryp)->d_name.name, + PFID(&lli->lli_fid), PFID(&nlli->lli_fid)); + dput(parent); + iput(sai->sai_inode); + GOTO(out, rc = -EAGAIN); + } - sta.sta_parent = (*dentryp)->d_parent; - sta.sta_pid = cfs_curproc_pid(); + CDEBUG(D_READA, "start statahead thread: [pid %d] [parent %.*s]\n", + cfs_curproc_pid(), parent->d_name.len, parent->d_name.name); lli->lli_sai = sai; - rc = cfs_kernel_thread(ll_statahead_thread, &sta, 0); + rc = cfs_create_thread(ll_statahead_thread, parent, 0); + thread = &sai->sai_thread; if (rc < 0) { CERROR("can't start ll_sa thread, rc: %d\n", rc); - sai->sai_thread.t_flags = SVC_STOPPED; + dput(parent); + lli->lli_opendir_key = NULL; + thread_set_flags(thread, SVC_STOPPED); + thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED); ll_sai_put(sai); LASSERT(lli->lli_sai == NULL); - RETURN(rc); + RETURN(-EAGAIN); } - l_wait_event(sai->sai_thread.t_ctl_waitq, - sai->sai_thread.t_flags & (SVC_RUNNING | SVC_STOPPED), + l_wait_event(thread->t_ctl_waitq, + thread_is_running(thread) || thread_is_stopped(thread), &lwi); - /* We don't stat-ahead for the first dirent since we are already in - * lookup, and -EEXIST also indicates that this is the first dirent. */ - RETURN(-EEXIST); -} - -/* update hit/miss count */ -void ll_statahead_exit(struct dentry *dentry, int result) -{ - struct dentry *parent = dentry->d_parent; - struct ll_inode_info *lli = ll_i2info(parent->d_inode); - struct ll_sb_info *sbi = ll_i2sbi(parent->d_inode); - struct ll_dentry_data *ldd = ll_d2d(dentry); - - if (lli->lli_opendir_pid != cfs_curproc_pid()) - return; + /* + * We don't stat-ahead for the first dirent since we are already in + * lookup. + */ + RETURN(-EAGAIN); - if (lli->lli_sai) { - struct ll_statahead_info *sai = lli->lli_sai; - - if (result == 1) { - sbi->ll_sa_hit++; - sai->sai_hit++; - sai->sai_consecutive_miss = 0; - sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max); - } else { - sbi->ll_sa_miss++; - sai->sai_miss++; - sai->sai_consecutive_miss++; - if (sa_low_hit(sai) && - sai->sai_thread.t_flags & SVC_RUNNING) { - sbi->ll_sa_wrong++; - CDEBUG(D_READA, "statahead for dir %.*s hit " - "ratio too low: hit/miss %u/%u, " - "sent/replied %u/%u. stopping statahead " - "thread: pid %d\n", - parent->d_name.len, parent->d_name.name, - sai->sai_hit, sai->sai_miss, - sai->sai_sent, sai->sai_replied, - cfs_curproc_pid()); - spin_lock(&lli->lli_lock); - if (!(sai->sai_thread.t_flags & SVC_STOPPED)) - sai->sai_thread.t_flags = SVC_STOPPING; - spin_unlock(&lli->lli_lock); - } - } - - cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq); - ll_sai_entry_put(sai); - - if (likely(ldd != NULL)) - ldd->lld_sa_generation = sai->sai_generation; - } +out: + if (sai != NULL) + OBD_FREE_PTR(sai); + spin_lock(&lli->lli_sa_lock); + lli->lli_opendir_key = NULL; + lli->lli_opendir_pid = 0; + spin_unlock(&lli->lli_sa_lock); + return rc; }