/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * 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. * * 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). * * 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 * * 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 2008 Sun Microsystems, Inc. All rights reserved * Use is subject to license terms. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. */ #include #include #include #include #include #include #define DEBUG_SUBSYSTEM S_LLITE #include #include #include #include #include "llite_internal.h" struct ll_sai_entry { struct list_head se_list; unsigned int se_index; int se_stat; struct ptlrpc_request *se_req; struct md_enqueue_info *se_minfo; }; enum { SA_ENTRY_UNSTATED = 0, SA_ENTRY_STATED }; struct dentry_operations ll_sai_d_ops = { .d_release = ll_release, }; static unsigned int sai_generation = 0; static spinlock_t sai_generation_lock = SPIN_LOCK_UNLOCKED; /** * 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 * (2) the statahead thread only add new entry to the list */ static int ll_sai_entry_stated(struct ll_statahead_info *sai) { struct ll_sai_entry *entry; int rc = 0; if (!list_empty(&sai->sai_entries_stated)) { entry = list_entry(sai->sai_entries_stated.next, struct ll_sai_entry, se_list); if (entry->se_index == sai->sai_index_next) rc = 1; } return rc; } static inline int sa_received_empty(struct ll_statahead_info *sai) { return list_empty(&sai->sai_entries_received); } static inline int sa_not_full(struct ll_statahead_info *sai) { return sai->sai_index < sai->sai_hit + sai->sai_miss + sai->sai_max; } static inline int sa_is_running(struct ll_statahead_info *sai) { return !!(sai->sai_thread.t_flags & SVC_RUNNING); } static inline int sa_is_stopping(struct ll_statahead_info *sai) { return !!(sai->sai_thread.t_flags & SVC_STOPPING); } static inline int sa_is_stopped(struct ll_statahead_info *sai) { return !!(sai->sai_thread.t_flags & SVC_STOPPED); } /** * (1) hit ratio less than 80% * or * (2) consecutive miss more than 8 */ static inline int sa_low_hit(struct ll_statahead_info *sai) { return ((sai->sai_hit < 4 * sai->sai_miss && sai->sai_hit > 7) || (sai->sai_consecutive_miss > 8)); } /** * process the deleted entry's member and free the entry. * (1) release intent * (2) free md_enqueue_info * (3) drop dentry's ref count * (4) release request's ref count */ static void ll_sai_entry_cleanup(struct ll_sai_entry *entry) { struct ptlrpc_request *req = entry->se_req; struct md_enqueue_info *minfo = entry->se_minfo; ENTRY; if (minfo) { struct dentry *dentry = minfo->mi_dentry; struct lookup_intent *it = &minfo->mi_it; entry->se_minfo = NULL; ll_intent_release(it); OBD_FREE_PTR(minfo); dput(dentry); } if (req) { entry->se_req = NULL; ptlrpc_req_finished(req); } OBD_FREE_PTR(entry); EXIT; } static struct ll_statahead_info *ll_sai_alloc(void) { struct ll_statahead_info *sai; 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_sent); CFS_INIT_LIST_HEAD(&sai->sai_entries_received); CFS_INIT_LIST_HEAD(&sai->sai_entries_stated); return sai; } static inline struct ll_statahead_info *ll_sai_get(struct ll_statahead_info *sai) { LASSERT(sai); 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; if (atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_lock)) { struct ll_sai_entry *entry, *next; lli->lli_sai = NULL; spin_unlock(&lli->lli_lock); LASSERT(sa_is_stopped(sai)); 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); list_for_each_entry_safe(entry, next, &sai->sai_entries_sent, se_list) { list_del(&entry->se_list); ll_sai_entry_cleanup(entry); } list_for_each_entry_safe(entry, next, &sai->sai_entries_received, se_list) { list_del(&entry->se_list); ll_sai_entry_cleanup(entry); } list_for_each_entry_safe(entry, next, &sai->sai_entries_stated, se_list) { list_del(&entry->se_list); ll_sai_entry_cleanup(entry); } dput(sai->sai_first); OBD_FREE_PTR(sai); iput(inode); } EXIT; } /** * insert it into sai_entries_sent tail when init. */ static struct ll_sai_entry * ll_sai_entry_init(struct ll_statahead_info *sai, unsigned int index) { struct ll_inode_info *lli = ll_i2info(sai->sai_inode); struct ll_sai_entry *entry; ENTRY; OBD_ALLOC_PTR(entry); if (entry == NULL) RETURN(ERR_PTR(-ENOMEM)); CDEBUG(D_READA, "alloc sai entry %p index %u\n", entry, index); entry->se_index = index; entry->se_stat = SA_ENTRY_UNSTATED; spin_lock(&lli->lli_lock); list_add_tail(&entry->se_list, &sai->sai_entries_sent); spin_unlock(&lli->lli_lock); RETURN(entry); } /** * delete it from sai_entries_stated head when fini, it need not * to process entry's member. */ static void ll_sai_entry_fini(struct ll_statahead_info *sai) { struct ll_inode_info *lli = ll_i2info(sai->sai_inode); struct ll_sai_entry *entry; ENTRY; spin_lock(&lli->lli_lock); sai->sai_index_next++; if (likely(!list_empty(&sai->sai_entries_stated))) { entry = list_entry(sai->sai_entries_stated.next, struct ll_sai_entry, se_list); if (entry->se_index < sai->sai_index_next) { list_del(&entry->se_list); OBD_FREE_PTR(entry); } } else LASSERT(sa_is_stopped(sai)); spin_unlock(&lli->lli_lock); EXIT; } /** * inside lli_lock. * \retval NULL : can not find the entry in sai_entries_sent with the index * \retval entry: find the entry in sai_entries_sent with the index */ static struct ll_sai_entry * ll_sai_entry_set(struct ll_statahead_info *sai, unsigned int index, int stat, struct ptlrpc_request *req, struct md_enqueue_info *minfo) { struct ll_sai_entry *entry; ENTRY; if (!list_empty(&sai->sai_entries_sent)) { list_for_each_entry(entry, &sai->sai_entries_sent, se_list) { if (entry->se_index == index) { entry->se_stat = stat; entry->se_req = ptlrpc_request_addref(req); entry->se_minfo = minfo; RETURN(entry); } else if (entry->se_index > index) RETURN(NULL); } } RETURN(NULL); } /** * inside lli_lock. * Move entry to sai_entries_received and * insert it into sai_entries_received tail. */ static inline void ll_sai_entry_to_received(struct ll_statahead_info *sai, struct ll_sai_entry *entry) { if (!list_empty(&entry->se_list)) list_del_init(&entry->se_list); list_add_tail(&entry->se_list, &sai->sai_entries_received); } /** * Move entry to sai_entries_stated and * sort with the index. */ static int ll_sai_entry_to_stated(struct ll_statahead_info *sai, struct ll_sai_entry *entry) { struct ll_inode_info *lli = ll_i2info(sai->sai_inode); struct ll_sai_entry *se; ENTRY; spin_lock(&lli->lli_lock); if (!list_empty(&entry->se_list)) list_del_init(&entry->se_list); if (unlikely(entry->se_index < sai->sai_index_next)) { spin_unlock(&lli->lli_lock); ll_sai_entry_cleanup(entry); RETURN(0); } list_for_each_entry_reverse(se, &sai->sai_entries_stated, se_list) { if (se->se_index < entry->se_index) { list_add(&entry->se_list, &se->se_list); spin_unlock(&lli->lli_lock); RETURN(1); } } /* * I am the first entry. */ list_add(&entry->se_list, &sai->sai_entries_stated); spin_unlock(&lli->lli_lock); RETURN(1); } /** * finish lookup/revalidate. */ static int do_statahead_interpret(struct ll_statahead_info *sai) { struct ll_inode_info *lli = ll_i2info(sai->sai_inode); struct ll_sai_entry *entry; struct ptlrpc_request *req; struct md_enqueue_info *minfo; struct dentry *dentry; struct lookup_intent *it; int rc = 0; ENTRY; spin_lock(&lli->lli_lock); LASSERT(!sa_received_empty(sai)); entry = list_entry(sai->sai_entries_received.next, struct ll_sai_entry, se_list); list_del_init(&entry->se_list); spin_unlock(&lli->lli_lock); if (unlikely(entry->se_index < sai->sai_index_next)) { ll_sai_entry_cleanup(entry); RETURN(0); } req = entry->se_req; minfo = entry->se_minfo; dentry = minfo->mi_dentry; it = &minfo->mi_it; if (entry->se_stat != SA_ENTRY_STATED) GOTO(out, rc = entry->se_stat); if (dentry->d_inode == NULL) { /* * lookup. */ struct dentry *save = dentry; struct it_cb_data icbd = { .icbd_parent = dentry->d_parent->d_inode, .icbd_childp = &dentry }; LASSERT(fid_is_zero(&minfo->mi_data.op_fid2)); 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); if (dentry != save) { minfo->mi_dentry = dentry; dput(save); } } else { /* * revalidate. */ struct mdt_body *body; 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); GOTO(out, rc = -EAGAIN); } rc = ll_revalidate_it_finish(req, it, dentry); if (rc) { ll_unhash_aliases(dentry->d_inode); GOTO(out, rc); } 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); ll_lookup_finish_locks(it, dentry); } EXIT; out: if (likely(ll_sai_entry_to_stated(sai, entry))) { entry->se_minfo = NULL; entry->se_req = NULL; cfs_waitq_signal(&sai->sai_waitq); ll_intent_release(it); OBD_FREE_PTR(minfo); dput(dentry); ptlrpc_req_finished(req); } return rc; } static int ll_statahead_interpret(struct ptlrpc_request *req, struct md_enqueue_info *minfo, int rc) { struct dentry *dentry = minfo->mi_dentry; struct lookup_intent *it = &minfo->mi_it; struct inode *dir = dentry->d_parent->d_inode; struct ll_inode_info *lli = ll_i2info(dir); struct ll_statahead_info *sai; struct ll_sai_entry *entry; ENTRY; CDEBUG(D_READA, "interpret statahead %.*s rc %d\n", dentry->d_name.len, dentry->d_name.name, rc); spin_lock(&lli->lli_lock); if (unlikely(lli->lli_sai == NULL || lli->lli_sai->sai_generation != minfo->mi_generation)) { spin_unlock(&lli->lli_lock); ll_intent_release(it); dput(dentry); OBD_FREE_PTR(minfo); RETURN(-ESTALE); } else { sai = lli->lli_sai; if (rc || dir == NULL) rc = -ESTALE; entry = ll_sai_entry_set(sai, (unsigned int)(long)minfo->mi_cbdata, rc ? SA_ENTRY_UNSTATED : SA_ENTRY_STATED, req, minfo); LASSERT(entry != NULL); if (likely(sa_is_running(sai))) { ll_sai_entry_to_received(sai, entry); sai->sai_replied++; spin_unlock(&lli->lli_lock); cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq); } else { if (!list_empty(&entry->se_list)) list_del_init(&entry->se_list); sai->sai_replied++; spin_unlock(&lli->lli_lock); ll_sai_entry_cleanup(entry); } RETURN(rc); } } static void sa_args_fini(struct md_enqueue_info *minfo, struct ldlm_enqueue_info *einfo) { LASSERT(minfo && einfo); 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 * 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, struct ldlm_enqueue_info **pei, struct obd_capa **pcapa) { struct ll_inode_info *lli = ll_i2info(dir); struct md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; struct md_op_data *op_data; OBD_ALLOC_PTR(einfo); if (einfo == NULL) return -ENOMEM; OBD_ALLOC_PTR(minfo); if (minfo == NULL) { OBD_FREE_PTR(einfo); 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); if (IS_ERR(op_data)) { OBD_FREE_PTR(einfo); OBD_FREE_PTR(minfo); return PTR_ERR(op_data); } minfo->mi_it.it_op = IT_GETATTR; minfo->mi_dentry = dentry; minfo->mi_cb = ll_statahead_interpret; minfo->mi_generation = lli->lli_sai->sai_generation; minfo->mi_cbdata = (void *)(long)lli->lli_sai->sai_index; einfo->ei_type = LDLM_IBITS; einfo->ei_mode = it_to_lock_mode(&minfo->mi_it); einfo->ei_cb_bl = ll_md_blocking_ast; einfo->ei_cb_cp = ldlm_completion_ast; einfo->ei_cb_gl = NULL; einfo->ei_cbdata = NULL; *pmi = minfo; *pei = einfo; pcapa[0] = op_data->op_capa1; pcapa[1] = op_data->op_capa2; return 0; } /** * similar to ll_lookup_it(). */ static int do_sa_lookup(struct inode *dir, struct dentry *dentry) { struct md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; struct obd_capa *capas[2]; int rc; ENTRY; rc = sa_args_init(dir, dentry, &minfo, &einfo, capas); if (rc) RETURN(rc); rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo); if (!rc) { capa_put(capas[0]); capa_put(capas[1]); } else { sa_args_fini(minfo, einfo); } RETURN(rc); } /** * 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 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 md_enqueue_info *minfo; struct ldlm_enqueue_info *einfo; struct obd_capa *capas[2]; int rc; ENTRY; if (inode == NULL) RETURN(1); if (d_mountpoint(dentry)) RETURN(1); if (dentry == dentry->d_sb->s_root) RETURN(1); rc = md_revalidate_lock(ll_i2mdexp(dir), &it, ll_inode2fid(inode)); if (rc == 1) { ll_intent_release(&it); RETURN(1); } rc = sa_args_init(dir, dentry, &minfo, &einfo, capas); if (rc) RETURN(rc); rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo); if (!rc) { capa_put(capas[0]); capa_put(capas[1]); } else { 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) { 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; int rc; 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_init(sai, sai->sai_index); if (IS_ERR(se)) RETURN(PTR_ERR(se)); ll_name2qstr(&name, entry_name, entry_name_len); dentry = d_lookup(parent, &name); if (!dentry) { dentry = d_alloc(parent, &name); if (dentry) { rc = do_sa_lookup(dir, dentry); if (rc) dput(dentry); } else { GOTO(out, rc = -ENOMEM); } } else { rc = do_sa_revalidate(dentry); if (rc) dput(dentry); } EXIT; 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; if (ll_sai_entry_to_stated(sai, se)) cfs_waitq_signal(&sai->sai_waitq); } else { sai->sai_sent++; } sai->sai_index++; return rc; } struct ll_sa_thread_args { struct dentry *sta_parent; pid_t sta_pid; }; 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 ptlrpc_thread *thread = &sai->sai_thread; struct page *page; __u64 pos = 0; int first = 0; int rc = 0; struct ll_dir_chain chain; ENTRY; { char pname[16]; snprintf(pname, 15, "ll_sa_%u", sta->sta_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); ll_dir_chain_init(&chain); page = ll_get_dir_page(dir, pos, 0, &chain); while (1) { struct l_wait_info lwi = { 0 }; struct lu_dirpage *dp; struct lu_dirent *ent; if (IS_ERR(page)) { rc = PTR_ERR(page); CERROR("error reading dir "DFID" at "LPU64"/%u: rc %d\n", PFID(ll_inode2fid(dir)), pos, sai->sai_index, rc); 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); if (namelen == 0) /* * Skip dummy record. */ continue; if (name[0] == '.') { if (namelen == 1) { /* * skip "." */ continue; } else if (name[1] == '.' && namelen == 2) { /* * skip ".." */ continue; } else if (!sai->sai_ls_all) { /* * skip hidden files. */ sai->sai_skip_hidden++; continue; } } /* * don't stat-ahead first entry. */ if (unlikely(!first)) { first++; continue; } keep_de: l_wait_event(thread->t_ctl_waitq, !sa_is_running(sai) || sa_not_full(sai) || !sa_received_empty(sai), &lwi); while (!sa_received_empty(sai) && sa_is_running(sai)) do_statahead_interpret(sai); if (unlikely(!sa_is_running(sai))) { ll_put_page(page); GOTO(out, rc); } if (!sa_not_full(sai)) /* * do not skip the current de. */ goto keep_de; rc = ll_statahead_one(parent, name, namelen); if (rc < 0) { ll_put_page(page); GOTO(out, rc); } } pos = le64_to_cpu(dp->ldp_hash_end); ll_put_page(page); if (pos == DIR_END_OFF) { /* * End of directory reached. */ while (1) { l_wait_event(thread->t_ctl_waitq, !sa_is_running(sai) || !sa_received_empty(sai) || sai->sai_sent == sai->sai_replied, &lwi); if (!sa_received_empty(sai) && sa_is_running(sai)) do_statahead_interpret(sai); else GOTO(out, rc); } } else if (1) { /* * chain is exhausted. * Normal case: continue to the next page. */ page = ll_get_dir_page(dir, pos, 1, &chain); } else { /* * go into overflow page. */ } } EXIT; out: ll_dir_chain_fini(&chain); spin_lock(&lli->lli_lock); thread->t_flags = SVC_STOPPED; spin_unlock(&lli->lli_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()); return rc; } /** * called in ll_file_release(). */ void ll_stop_statahead(struct inode *inode, void *key) { struct ll_inode_info *lli = ll_i2info(inode); struct ptlrpc_thread *thread; spin_lock(&lli->lli_lock); if (lli->lli_opendir_pid == 0 || unlikely(lli->lli_opendir_key != key)) { spin_unlock(&lli->lli_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 (!sa_is_stopped(lli->lli_sai)) { 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, sa_is_stopped(lli->lli_sai), &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); } enum { /** * not first dirent, or is "." */ LS_NONE_FIRST_DE = 0, /** * the first non-hidden dirent */ LS_FIRST_DE, /** * the first hidden dirent, that is ".xxx */ 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; ENTRY; ll_dir_chain_init(&chain); page = ll_get_dir_page(dir, pos, 0, &chain); while (1) { struct lu_dirpage *dp; struct lu_dirent *ent; if (IS_ERR(page)) { rc = PTR_ERR(page); CERROR("error reading dir "DFID" at "LPU64": rc %d\n", PFID(ll_inode2fid(dir)), pos, rc); 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); if (namelen == 0) /* * skip dummy record. */ continue; if (name[0] == '.') { if (namelen == 1) /* * skip "." */ continue; else if (name[1] == '.' && namelen == 2) /* * skip ".." */ continue; else dot_de = 1; } else { dot_de = 0; } if (dot_de && target->name[0] != '.') { CDEBUG(D_READA, "%.*s skip hidden file %.*s\n", target->len, target->name, namelen, name); continue; } if (target->len == namelen && !strncmp(target->name, name, target->len)) rc = LS_FIRST_DE + dot_de; else rc = LS_NONE_FIRST_DE; ll_put_page(page); GOTO(out, rc); } 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); } else { /* * go into overflow page. */ } } EXIT; out: ll_dir_chain_fini(&chain); return rc; } /** * 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. * \retval 0 -- stat ahead thread process such dentry, for lookup, it miss * \retval 1 -- stat ahead thread process such dentry, for lookup, it hit * \retval -EEXIST -- stat ahead thread started, and this is the first dentry * \retval -EBADFD -- statahead thread exit and not dentry available * \retval 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; ENTRY; LASSERT(lli->lli_opendir_pid == cfs_curproc_pid()); if (sai) { if (unlikely(sa_is_stopped(sai) && list_empty(&sai->sai_entries_stated))) RETURN(-EBADFD); /* * skip the first dentry. */ if (unlikely((*dentryp)->d_name.len == sai->sai_first->d_name.len && !strncmp((*dentryp)->d_name.name, sai->sai_first->d_name.name, sai->sai_first->d_name.len))) RETURN(-EEXIST); 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 * thread does not skip so many hidden dentries * before "sai_ls_all" enabled as below. */ } else { if (!sai->sai_ls_all) /* * 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->sai_ls_all = 1; /* * Such "getattr" has been skipped before * "sai_ls_all" enabled as above. */ sai->sai_miss_hidden++; RETURN(-ENOENT); } } 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) || sa_is_stopped(sai), &lwi); } if (lookup) { struct dentry *result; result = d_lookup((*dentryp)->d_parent, &(*dentryp)->d_name); if (result) { LASSERT(result != *dentryp); dput(*dentryp); *dentryp = result; RETURN(1); } } /* * do nothing for revalidate. */ RETURN(0); } /* * I am the "lli_opendir_pid" owner, only me can set "lli_sai". */ LASSERT(lli->lli_sai == NULL); 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); } sai = ll_sai_alloc(); if (sai == NULL) RETURN(-ENOMEM); sai->sai_inode = igrab(dir); sai->sai_first = dget(*dentryp); sai->sai_ls_all = (rc == LS_FIRST_DOT_DE); sta.sta_parent = (*dentryp)->d_parent; sta.sta_pid = cfs_curproc_pid(); lli->lli_sai = sai; rc = cfs_kernel_thread(ll_statahead_thread, &sta, 0); if (rc < 0) { CERROR("can't start ll_sa thread, rc: %d\n", rc); sai->sai_thread.t_flags = SVC_STOPPED; ll_sai_put(sai); LASSERT(lli->lli_sai == NULL); RETURN(rc); } l_wait_event(sai->sai_thread.t_ctl_waitq, sa_is_running(sai) || sa_is_stopped(sai), &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. */ int 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); ENTRY; if (lli->lli_opendir_pid != cfs_curproc_pid()) RETURN(-EBADFD); 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) && sa_is_running(sai)) { 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 (!sa_is_stopped(sai)) sai->sai_thread.t_flags = SVC_STOPPING; spin_unlock(&lli->lli_lock); } } if (!sa_is_stopped(sai)) cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq); ll_sai_entry_fini(sai); if (unlikely(ldd == NULL)) { ll_set_dd(dentry); ldd = ll_d2d(dentry); if (ldd != NULL && dentry->d_op == NULL) { lock_dentry(dentry); dentry->d_op = dentry->d_op ? : &ll_sai_d_ops; unlock_dentry(dentry); } } if (likely(ldd != NULL)) ldd->lld_sa_generation = sai->sai_generation; else RETURN(-ENOMEM); } RETURN(0); }