/* * 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 (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. * Use is subject to license terms. * * Copyright (c) 2012, 2013, Intel Corporation. * */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. * * osc cache management. * * Author: Jinshan Xiong */ #define DEBUG_SUBSYSTEM S_OSC #include "osc_cl_internal.h" #include "osc_internal.h" static int extent_debug; /* set it to be true for more debug */ static void osc_update_pending(struct osc_object *obj, int cmd, int delta); static int osc_extent_wait(const struct lu_env *env, struct osc_extent *ext, int state); static void osc_ap_completion(const struct lu_env *env, struct client_obd *cli, struct osc_async_page *oap, int sent, int rc); static int osc_make_ready(const struct lu_env *env, struct osc_async_page *oap, int cmd); static int osc_refresh_count(const struct lu_env *env, struct osc_async_page *oap, int cmd); static int osc_io_unplug_async(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc); static void osc_free_grant(struct client_obd *cli, unsigned int nr_pages, unsigned int lost_grant); static void osc_extent_tree_dump0(int level, struct osc_object *obj, const char *func, int line); #define osc_extent_tree_dump(lvl, obj) \ osc_extent_tree_dump0(lvl, obj, __func__, __LINE__) /** \addtogroup osc * @{ */ /* ------------------ osc extent ------------------ */ static inline char *ext_flags(struct osc_extent *ext, char *flags) { char *buf = flags; *buf++ = ext->oe_rw ? 'r' : 'w'; if (ext->oe_intree) *buf++ = 'i'; if (ext->oe_srvlock) *buf++ = 's'; if (ext->oe_hp) *buf++ = 'h'; if (ext->oe_urgent) *buf++ = 'u'; if (ext->oe_memalloc) *buf++ = 'm'; if (ext->oe_trunc_pending) *buf++ = 't'; if (ext->oe_fsync_wait) *buf++ = 'Y'; *buf = 0; return flags; } static inline char list_empty_marker(struct list_head *list) { return list_empty(list) ? '-' : '+'; } #define EXTSTR "[%lu -> %lu/%lu]" #define EXTPARA(ext) (ext)->oe_start, (ext)->oe_end, (ext)->oe_max_end static const char *oes_strings[] = { "inv", "active", "cache", "locking", "lockdone", "rpc", "trunc", NULL }; #define OSC_EXTENT_DUMP(lvl, extent, fmt, ...) do { \ struct osc_extent *__ext = (extent); \ char __buf[16]; \ \ CDEBUG(lvl, \ "extent %p@{" EXTSTR ", " \ "[%d|%d|%c|%s|%s|%p], [%d|%d|%c|%c|%p|%u|%p]} " fmt, \ /* ----- extent part 0 ----- */ \ __ext, EXTPARA(__ext), \ /* ----- part 1 ----- */ \ atomic_read(&__ext->oe_refc), \ atomic_read(&__ext->oe_users), \ list_empty_marker(&__ext->oe_link), \ oes_strings[__ext->oe_state], ext_flags(__ext, __buf), \ __ext->oe_obj, \ /* ----- part 2 ----- */ \ __ext->oe_grants, __ext->oe_nr_pages, \ list_empty_marker(&__ext->oe_pages), \ waitqueue_active(&__ext->oe_waitq) ? '+' : '-', \ __ext->oe_osclock, __ext->oe_mppr, __ext->oe_owner, \ /* ----- part 4 ----- */ \ ## __VA_ARGS__); \ } while (0) #undef EASSERTF #define EASSERTF(expr, ext, fmt, args...) do { \ if (!(expr)) { \ OSC_EXTENT_DUMP(D_ERROR, (ext), fmt, ##args); \ osc_extent_tree_dump(D_ERROR, (ext)->oe_obj); \ LASSERT(expr); \ } \ } while (0) #undef EASSERT #define EASSERT(expr, ext) EASSERTF(expr, ext, "\n") static inline struct osc_extent *rb_extent(struct rb_node *n) { if (n == NULL) return NULL; return container_of(n, struct osc_extent, oe_node); } static inline struct osc_extent *next_extent(struct osc_extent *ext) { if (ext == NULL) return NULL; LASSERT(ext->oe_intree); return rb_extent(rb_next(&ext->oe_node)); } static inline struct osc_extent *prev_extent(struct osc_extent *ext) { if (ext == NULL) return NULL; LASSERT(ext->oe_intree); return rb_extent(rb_prev(&ext->oe_node)); } static inline struct osc_extent *first_extent(struct osc_object *obj) { return rb_extent(rb_first(&obj->oo_root)); } /* object must be locked by caller. */ static int osc_extent_sanity_check0(struct osc_extent *ext, const char *func, const int line) { struct osc_object *obj = ext->oe_obj; struct osc_async_page *oap; int page_count; int rc = 0; if (!osc_object_is_locked(obj)) GOTO(out, rc = 9); if (ext->oe_state >= OES_STATE_MAX) GOTO(out, rc = 10); if (atomic_read(&ext->oe_refc) <= 0) GOTO(out, rc = 20); if (atomic_read(&ext->oe_refc) < atomic_read(&ext->oe_users)) GOTO(out, rc = 30); switch (ext->oe_state) { case OES_INV: if (ext->oe_nr_pages > 0 || !list_empty(&ext->oe_pages)) GOTO(out, rc = 35); GOTO(out, rc = 0); break; case OES_ACTIVE: if (atomic_read(&ext->oe_users) == 0) GOTO(out, rc = 40); if (ext->oe_hp) GOTO(out, rc = 50); if (ext->oe_fsync_wait && !ext->oe_urgent) GOTO(out, rc = 55); break; case OES_CACHE: if (ext->oe_grants == 0) GOTO(out, rc = 60); if (ext->oe_fsync_wait && !ext->oe_urgent && !ext->oe_hp) GOTO(out, rc = 65); default: if (atomic_read(&ext->oe_users) > 0) GOTO(out, rc = 70); } if (ext->oe_max_end < ext->oe_end || ext->oe_end < ext->oe_start) GOTO(out, rc = 80); if (ext->oe_osclock == NULL && ext->oe_grants > 0) GOTO(out, rc = 90); if (ext->oe_osclock) { struct cl_lock_descr *descr; descr = &ext->oe_osclock->cll_descr; if (!(descr->cld_start <= ext->oe_start && descr->cld_end >= ext->oe_max_end)) GOTO(out, rc = 100); } if (ext->oe_nr_pages > ext->oe_mppr) GOTO(out, rc = 105); /* Do not verify page list if extent is in RPC. This is because an * in-RPC extent is supposed to be exclusively accessible w/o lock. */ if (ext->oe_state > OES_CACHE) GOTO(out, rc = 0); if (!extent_debug) GOTO(out, rc = 0); page_count = 0; list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) { pgoff_t index = osc_index(oap2osc(oap)); ++page_count; if (index > ext->oe_end || index < ext->oe_start) GOTO(out, rc = 110); } if (page_count != ext->oe_nr_pages) GOTO(out, rc = 120); out: if (rc != 0) OSC_EXTENT_DUMP(D_ERROR, ext, "%s:%d sanity check %p failed with rc = %d\n", func, line, ext, rc); return rc; } #define sanity_check_nolock(ext) \ osc_extent_sanity_check0(ext, __func__, __LINE__) #define sanity_check(ext) ({ \ int __res; \ osc_object_lock((ext)->oe_obj); \ __res = sanity_check_nolock(ext); \ osc_object_unlock((ext)->oe_obj); \ __res; \ }) /** * sanity check - to make sure there is no overlapped extent in the tree. */ static int osc_extent_is_overlapped(struct osc_object *obj, struct osc_extent *ext) { struct osc_extent *tmp; LASSERT(osc_object_is_locked(obj)); if (!extent_debug) return 0; for (tmp = first_extent(obj); tmp != NULL; tmp = next_extent(tmp)) { if (tmp == ext) continue; if (tmp->oe_end >= ext->oe_start && tmp->oe_start <= ext->oe_end) return 1; } return 0; } static void osc_extent_state_set(struct osc_extent *ext, int state) { LASSERT(osc_object_is_locked(ext->oe_obj)); LASSERT(state >= OES_INV && state < OES_STATE_MAX); /* Never try to sanity check a state changing extent :-) */ /* LASSERT(sanity_check_nolock(ext) == 0); */ /* TODO: validate the state machine */ ext->oe_state = state; wake_up_all(&ext->oe_waitq); } static struct osc_extent *osc_extent_alloc(struct osc_object *obj) { struct osc_extent *ext; OBD_SLAB_ALLOC_PTR_GFP(ext, osc_extent_kmem, GFP_IOFS); if (ext == NULL) return NULL; RB_CLEAR_NODE(&ext->oe_node); ext->oe_obj = obj; atomic_set(&ext->oe_refc, 1); atomic_set(&ext->oe_users, 0); INIT_LIST_HEAD(&ext->oe_link); ext->oe_state = OES_INV; INIT_LIST_HEAD(&ext->oe_pages); init_waitqueue_head(&ext->oe_waitq); ext->oe_osclock = NULL; return ext; } static void osc_extent_free(struct osc_extent *ext) { OBD_SLAB_FREE_PTR(ext, osc_extent_kmem); } static struct osc_extent *osc_extent_get(struct osc_extent *ext) { LASSERT(atomic_read(&ext->oe_refc) >= 0); atomic_inc(&ext->oe_refc); return ext; } static void osc_extent_put(const struct lu_env *env, struct osc_extent *ext) { LASSERT(atomic_read(&ext->oe_refc) > 0); if (atomic_dec_and_test(&ext->oe_refc)) { LASSERT(list_empty(&ext->oe_link)); LASSERT(atomic_read(&ext->oe_users) == 0); LASSERT(ext->oe_state == OES_INV); LASSERT(!ext->oe_intree); if (ext->oe_osclock) { cl_lock_put(env, ext->oe_osclock); ext->oe_osclock = NULL; } osc_extent_free(ext); } } /** * osc_extent_put_trust() is a special version of osc_extent_put() when * it's known that the caller is not the last user. This is to address the * problem of lacking of lu_env ;-). */ static void osc_extent_put_trust(struct osc_extent *ext) { LASSERT(atomic_read(&ext->oe_refc) > 1); LASSERT(osc_object_is_locked(ext->oe_obj)); atomic_dec(&ext->oe_refc); } /** * Return the extent which includes pgoff @index, or return the greatest * previous extent in the tree. */ static struct osc_extent *osc_extent_search(struct osc_object *obj, pgoff_t index) { struct rb_node *n = obj->oo_root.rb_node; struct osc_extent *tmp, *p = NULL; LASSERT(osc_object_is_locked(obj)); while (n != NULL) { tmp = rb_extent(n); if (index < tmp->oe_start) { n = n->rb_left; } else if (index > tmp->oe_end) { p = rb_extent(n); n = n->rb_right; } else { return tmp; } } return p; } /* * Return the extent covering @index, otherwise return NULL. * caller must have held object lock. */ static struct osc_extent *osc_extent_lookup(struct osc_object *obj, pgoff_t index) { struct osc_extent *ext; ext = osc_extent_search(obj, index); if (ext != NULL && ext->oe_start <= index && index <= ext->oe_end) return osc_extent_get(ext); return NULL; } /* caller must have held object lock. */ static void osc_extent_insert(struct osc_object *obj, struct osc_extent *ext) { struct rb_node **n = &obj->oo_root.rb_node; struct rb_node *parent = NULL; struct osc_extent *tmp; LASSERT(ext->oe_intree == 0); LASSERT(ext->oe_obj == obj); LASSERT(osc_object_is_locked(obj)); while (*n != NULL) { tmp = rb_extent(*n); parent = *n; if (ext->oe_end < tmp->oe_start) n = &(*n)->rb_left; else if (ext->oe_start > tmp->oe_end) n = &(*n)->rb_right; else EASSERTF(0, tmp, EXTSTR"\n", EXTPARA(ext)); } rb_link_node(&ext->oe_node, parent, n); rb_insert_color(&ext->oe_node, &obj->oo_root); osc_extent_get(ext); ext->oe_intree = 1; } /* caller must have held object lock. */ static void osc_extent_erase(struct osc_extent *ext) { struct osc_object *obj = ext->oe_obj; LASSERT(osc_object_is_locked(obj)); if (ext->oe_intree) { rb_erase(&ext->oe_node, &obj->oo_root); ext->oe_intree = 0; /* rbtree held a refcount */ osc_extent_put_trust(ext); } } static struct osc_extent *osc_extent_hold(struct osc_extent *ext) { struct osc_object *obj = ext->oe_obj; LASSERT(osc_object_is_locked(obj)); LASSERT(ext->oe_state == OES_ACTIVE || ext->oe_state == OES_CACHE); if (ext->oe_state == OES_CACHE) { osc_extent_state_set(ext, OES_ACTIVE); osc_update_pending(obj, OBD_BRW_WRITE, -ext->oe_nr_pages); } atomic_inc(&ext->oe_users); list_del_init(&ext->oe_link); return osc_extent_get(ext); } static void __osc_extent_remove(struct osc_extent *ext) { LASSERT(osc_object_is_locked(ext->oe_obj)); LASSERT(list_empty(&ext->oe_pages)); osc_extent_erase(ext); list_del_init(&ext->oe_link); osc_extent_state_set(ext, OES_INV); OSC_EXTENT_DUMP(D_CACHE, ext, "destroyed.\n"); } static void osc_extent_remove(struct osc_extent *ext) { struct osc_object *obj = ext->oe_obj; osc_object_lock(obj); __osc_extent_remove(ext); osc_object_unlock(obj); } /** * This function is used to merge extents to get better performance. It checks * if @cur and @victim are contiguous at chunk level. */ static int osc_extent_merge(const struct lu_env *env, struct osc_extent *cur, struct osc_extent *victim) { struct osc_object *obj = cur->oe_obj; pgoff_t chunk_start; pgoff_t chunk_end; int ppc_bits; LASSERT(cur->oe_state == OES_CACHE); LASSERT(osc_object_is_locked(obj)); if (victim == NULL) return -EINVAL; if (victim->oe_state != OES_CACHE || victim->oe_fsync_wait) return -EBUSY; if (cur->oe_max_end != victim->oe_max_end) return -ERANGE; LASSERT(cur->oe_osclock == victim->oe_osclock); ppc_bits = osc_cli(obj)->cl_chunkbits - PAGE_CACHE_SHIFT; chunk_start = cur->oe_start >> ppc_bits; chunk_end = cur->oe_end >> ppc_bits; if (chunk_start != (victim->oe_end >> ppc_bits) + 1 && chunk_end + 1 != victim->oe_start >> ppc_bits) return -ERANGE; OSC_EXTENT_DUMP(D_CACHE, victim, "will be merged by %p.\n", cur); cur->oe_start = min(cur->oe_start, victim->oe_start); cur->oe_end = max(cur->oe_end, victim->oe_end); cur->oe_grants += victim->oe_grants; cur->oe_nr_pages += victim->oe_nr_pages; /* only the following bits are needed to merge */ cur->oe_urgent |= victim->oe_urgent; cur->oe_memalloc |= victim->oe_memalloc; list_splice_init(&victim->oe_pages, &cur->oe_pages); list_del_init(&victim->oe_link); victim->oe_nr_pages = 0; osc_extent_get(victim); __osc_extent_remove(victim); osc_extent_put(env, victim); OSC_EXTENT_DUMP(D_CACHE, cur, "after merging %p.\n", victim); return 0; } /** * Drop user count of osc_extent, and unplug IO asynchronously. */ int osc_extent_release(const struct lu_env *env, struct osc_extent *ext) { struct osc_object *obj = ext->oe_obj; int rc = 0; ENTRY; LASSERT(atomic_read(&ext->oe_users) > 0); LASSERT(sanity_check(ext) == 0); LASSERT(ext->oe_grants > 0); if (atomic_dec_and_lock(&ext->oe_users, &obj->oo_lock)) { LASSERT(ext->oe_state == OES_ACTIVE); if (ext->oe_trunc_pending) { /* a truncate process is waiting for this extent. * This may happen due to a race, check * osc_cache_truncate_start(). */ osc_extent_state_set(ext, OES_TRUNC); ext->oe_trunc_pending = 0; } else { osc_extent_state_set(ext, OES_CACHE); osc_update_pending(obj, OBD_BRW_WRITE, ext->oe_nr_pages); /* try to merge the previous and next extent. */ osc_extent_merge(env, ext, prev_extent(ext)); osc_extent_merge(env, ext, next_extent(ext)); if (ext->oe_urgent) list_move_tail(&ext->oe_link, &obj->oo_urgent_exts); } osc_object_unlock(obj); osc_io_unplug_async(env, osc_cli(obj), obj); } osc_extent_put(env, ext); RETURN(rc); } static inline int overlapped(struct osc_extent *ex1, struct osc_extent *ex2) { return !(ex1->oe_end < ex2->oe_start || ex2->oe_end < ex1->oe_start); } /** * Find or create an extent which includes @index, core function to manage * extent tree. */ struct osc_extent *osc_extent_find(const struct lu_env *env, struct osc_object *obj, pgoff_t index, int *grants) { struct client_obd *cli = osc_cli(obj); struct cl_lock *lock; struct osc_extent *cur; struct osc_extent *ext; struct osc_extent *conflict = NULL; struct osc_extent *found = NULL; pgoff_t chunk; pgoff_t max_end; int max_pages; /* max_pages_per_rpc */ int chunksize; int ppc_bits; /* pages per chunk bits */ int chunk_mask; int rc; ENTRY; cur = osc_extent_alloc(obj); if (cur == NULL) RETURN(ERR_PTR(-ENOMEM)); lock = cl_lock_at_pgoff(env, osc2cl(obj), index, NULL, 1, 0); LASSERT(lock != NULL); LASSERT(lock->cll_descr.cld_mode >= CLM_WRITE); LASSERT(cli->cl_chunkbits >= PAGE_CACHE_SHIFT); ppc_bits = cli->cl_chunkbits - PAGE_CACHE_SHIFT; chunk_mask = ~((1 << ppc_bits) - 1); chunksize = 1 << cli->cl_chunkbits; chunk = index >> ppc_bits; /* align end to rpc edge, rpc size may not be a power 2 integer. */ max_pages = cli->cl_max_pages_per_rpc; LASSERT((max_pages & ~chunk_mask) == 0); max_end = index - (index % max_pages) + max_pages - 1; max_end = min_t(pgoff_t, max_end, lock->cll_descr.cld_end); /* initialize new extent by parameters so far */ cur->oe_max_end = max_end; cur->oe_start = index & chunk_mask; cur->oe_end = ((index + ~chunk_mask + 1) & chunk_mask) - 1; if (cur->oe_start < lock->cll_descr.cld_start) cur->oe_start = lock->cll_descr.cld_start; if (cur->oe_end > max_end) cur->oe_end = max_end; cur->oe_osclock = lock; cur->oe_grants = 0; cur->oe_mppr = max_pages; /* grants has been allocated by caller */ LASSERTF(*grants >= chunksize + cli->cl_extent_tax, "%u/%u/%u.\n", *grants, chunksize, cli->cl_extent_tax); LASSERTF((max_end - cur->oe_start) < max_pages, EXTSTR"\n", EXTPARA(cur)); restart: osc_object_lock(obj); ext = osc_extent_search(obj, cur->oe_start); if (ext == NULL) ext = first_extent(obj); while (ext != NULL) { loff_t ext_chk_start = ext->oe_start >> ppc_bits; loff_t ext_chk_end = ext->oe_end >> ppc_bits; LASSERT(sanity_check_nolock(ext) == 0); if (chunk > ext_chk_end + 1) break; /* if covering by different locks, no chance to match */ if (lock != ext->oe_osclock) { EASSERTF(!overlapped(ext, cur), ext, EXTSTR"\n", EXTPARA(cur)); ext = next_extent(ext); continue; } /* discontiguous chunks? */ if (chunk + 1 < ext_chk_start) { ext = next_extent(ext); continue; } /* ok, from now on, ext and cur have these attrs: * 1. covered by the same lock * 2. contiguous at chunk level or overlapping. */ if (overlapped(ext, cur)) { /* cur is the minimum unit, so overlapping means * full contain. */ EASSERTF((ext->oe_start <= cur->oe_start && ext->oe_end >= cur->oe_end), ext, EXTSTR"\n", EXTPARA(cur)); if (ext->oe_state > OES_CACHE || ext->oe_fsync_wait) { /* for simplicity, we wait for this extent to * finish before going forward. */ conflict = osc_extent_get(ext); break; } found = osc_extent_hold(ext); break; } /* non-overlapped extent */ if (ext->oe_state != OES_CACHE || ext->oe_fsync_wait) { /* we can't do anything for a non OES_CACHE extent, or * if there is someone waiting for this extent to be * flushed, try next one. */ ext = next_extent(ext); continue; } /* check if they belong to the same rpc slot before trying to * merge. the extents are not overlapped and contiguous at * chunk level to get here. */ if (ext->oe_max_end != max_end) { /* if they don't belong to the same RPC slot or * max_pages_per_rpc has ever changed, do not merge. */ ext = next_extent(ext); continue; } /* it's required that an extent must be contiguous at chunk * level so that we know the whole extent is covered by grant * (the pages in the extent are NOT required to be contiguous). * Otherwise, it will be too much difficult to know which * chunks have grants allocated. */ /* try to do front merge - extend ext's start */ if (chunk + 1 == ext_chk_start) { /* ext must be chunk size aligned */ EASSERT((ext->oe_start & ~chunk_mask) == 0, ext); /* pull ext's start back to cover cur */ ext->oe_start = cur->oe_start; ext->oe_grants += chunksize; *grants -= chunksize; found = osc_extent_hold(ext); } else if (chunk == ext_chk_end + 1) { /* rear merge */ ext->oe_end = cur->oe_end; ext->oe_grants += chunksize; *grants -= chunksize; /* try to merge with the next one because we just fill * in a gap */ if (osc_extent_merge(env, ext, next_extent(ext)) == 0) /* we can save extent tax from next extent */ *grants += cli->cl_extent_tax; found = osc_extent_hold(ext); } if (found != NULL) break; ext = next_extent(ext); } osc_extent_tree_dump(D_CACHE, obj); if (found != NULL) { LASSERT(conflict == NULL); if (!IS_ERR(found)) { LASSERT(found->oe_osclock == cur->oe_osclock); OSC_EXTENT_DUMP(D_CACHE, found, "found caching ext for %lu.\n", index); } } else if (conflict == NULL) { /* create a new extent */ EASSERT(osc_extent_is_overlapped(obj, cur) == 0, cur); cur->oe_grants = chunksize + cli->cl_extent_tax; *grants -= cur->oe_grants; LASSERT(*grants >= 0); cur->oe_state = OES_CACHE; found = osc_extent_hold(cur); osc_extent_insert(obj, cur); OSC_EXTENT_DUMP(D_CACHE, cur, "add into tree %lu/%lu.\n", index, lock->cll_descr.cld_end); } osc_object_unlock(obj); if (conflict != NULL) { LASSERT(found == NULL); /* waiting for IO to finish. Please notice that it's impossible * to be an OES_TRUNC extent. */ rc = osc_extent_wait(env, conflict, OES_INV); osc_extent_put(env, conflict); conflict = NULL; if (rc < 0) GOTO(out, found = ERR_PTR(rc)); goto restart; } EXIT; out: osc_extent_put(env, cur); LASSERT(*grants >= 0); return found; } /** * Called when IO is finished to an extent. */ int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext, int sent, int rc) { struct client_obd *cli = osc_cli(ext->oe_obj); struct osc_async_page *oap; struct osc_async_page *tmp; int nr_pages = ext->oe_nr_pages; int lost_grant = 0; int blocksize = cli->cl_import->imp_obd->obd_osfs.os_bsize ? : 4096; __u64 last_off = 0; int last_count = -1; ENTRY; OSC_EXTENT_DUMP(D_CACHE, ext, "extent finished.\n"); ext->oe_rc = rc ?: ext->oe_nr_pages; EASSERT(ergo(rc == 0, ext->oe_state == OES_RPC), ext); osc_lru_add_batch(cli, &ext->oe_pages); list_for_each_entry_safe(oap, tmp, &ext->oe_pages, oap_pending_item) { list_del_init(&oap->oap_rpc_item); list_del_init(&oap->oap_pending_item); if (last_off <= oap->oap_obj_off) { last_off = oap->oap_obj_off; last_count = oap->oap_count; } --ext->oe_nr_pages; osc_ap_completion(env, cli, oap, sent, rc); } EASSERT(ext->oe_nr_pages == 0, ext); if (!sent) { lost_grant = ext->oe_grants; } else if (blocksize < PAGE_CACHE_SIZE && last_count != PAGE_CACHE_SIZE) { /* For short writes we shouldn't count parts of pages that * span a whole chunk on the OST side, or our accounting goes * wrong. Should match the code in filter_grant_check. */ int offset = last_off & ~CFS_PAGE_MASK; int count = last_count + (offset & (blocksize - 1)); int end = (offset + last_count) & (blocksize - 1); if (end) count += blocksize - end; lost_grant = PAGE_CACHE_SIZE - count; } if (ext->oe_grants > 0) osc_free_grant(cli, nr_pages, lost_grant); osc_extent_remove(ext); /* put the refcount for RPC */ osc_extent_put(env, ext); RETURN(0); } static int extent_wait_cb(struct osc_extent *ext, int state) { int ret; osc_object_lock(ext->oe_obj); ret = ext->oe_state == state; osc_object_unlock(ext->oe_obj); return ret; } /** * Wait for the extent's state to become @state. */ static int osc_extent_wait(const struct lu_env *env, struct osc_extent *ext, int state) { struct osc_object *obj = ext->oe_obj; struct l_wait_info lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(600), NULL, LWI_ON_SIGNAL_NOOP, NULL); int rc = 0; ENTRY; osc_object_lock(obj); LASSERT(sanity_check_nolock(ext) == 0); /* `Kick' this extent only if the caller is waiting for it to be * written out. */ if (state == OES_INV && !ext->oe_urgent && !ext->oe_hp) { if (ext->oe_state == OES_ACTIVE) { ext->oe_urgent = 1; } else if (ext->oe_state == OES_CACHE) { ext->oe_urgent = 1; osc_extent_hold(ext); rc = 1; } } osc_object_unlock(obj); if (rc == 1) osc_extent_release(env, ext); /* wait for the extent until its state becomes @state */ rc = l_wait_event(ext->oe_waitq, extent_wait_cb(ext, state), &lwi); if (rc == -ETIMEDOUT) { OSC_EXTENT_DUMP(D_ERROR, ext, "%s: wait ext to %d timedout, recovery in progress?\n", osc_export(obj)->exp_obd->obd_name, state); lwi = LWI_INTR(NULL, NULL); rc = l_wait_event(ext->oe_waitq, extent_wait_cb(ext, state), &lwi); } if (rc == 0 && ext->oe_rc < 0) rc = ext->oe_rc; RETURN(rc); } /** * Discard pages with index greater than @size. If @ext is overlapped with * @size, then partial truncate happens. */ static int osc_extent_truncate(struct osc_extent *ext, pgoff_t trunc_index, bool partial) { struct cl_env_nest nest; struct lu_env *env; struct cl_io *io; struct osc_object *obj = ext->oe_obj; struct client_obd *cli = osc_cli(obj); struct osc_async_page *oap; struct osc_async_page *tmp; int pages_in_chunk = 0; int ppc_bits = cli->cl_chunkbits - PAGE_CACHE_SHIFT; __u64 trunc_chunk = trunc_index >> ppc_bits; int grants = 0; int nr_pages = 0; int rc = 0; ENTRY; LASSERT(sanity_check(ext) == 0); LASSERT(ext->oe_state == OES_TRUNC); LASSERT(!ext->oe_urgent); /* Request new lu_env. * We can't use that env from osc_cache_truncate_start() because * it's from lov_io_sub and not fully initialized. */ env = cl_env_nested_get(&nest); io = &osc_env_info(env)->oti_io; io->ci_obj = cl_object_top(osc2cl(obj)); rc = cl_io_init(env, io, CIT_MISC, io->ci_obj); if (rc < 0) GOTO(out, rc); /* discard all pages with index greater then trunc_index */ list_for_each_entry_safe(oap, tmp, &ext->oe_pages, oap_pending_item) { pgoff_t index = osc_index(oap2osc(oap)); struct cl_page *page = oap2cl_page(oap); LASSERT(list_empty(&oap->oap_rpc_item)); /* only discard the pages with their index greater than * trunc_index, and ... */ if (index < trunc_index || (index == trunc_index && partial)) { /* accounting how many pages remaining in the chunk * so that we can calculate grants correctly. */ if (index >> ppc_bits == trunc_chunk) ++pages_in_chunk; continue; } list_del_init(&oap->oap_pending_item); cl_page_get(page); lu_ref_add(&page->cp_reference, "truncate", current); if (cl_page_own(env, io, page) == 0) { cl_page_discard(env, io, page); cl_page_disown(env, io, page); } else { LASSERT(page->cp_state == CPS_FREEING); LASSERT(0); } lu_ref_del(&page->cp_reference, "truncate", current); cl_page_put(env, page); --ext->oe_nr_pages; ++nr_pages; } EASSERTF(ergo(ext->oe_start >= trunc_index + !!partial, ext->oe_nr_pages == 0), ext, "trunc_index %lu, partial %d\n", trunc_index, partial); osc_object_lock(obj); if (ext->oe_nr_pages == 0) { LASSERT(pages_in_chunk == 0); grants = ext->oe_grants; ext->oe_grants = 0; } else { /* calculate how many grants we can free */ int chunks = (ext->oe_end >> ppc_bits) - trunc_chunk; pgoff_t last_index; /* if there is no pages in this chunk, we can also free grants * for the last chunk */ if (pages_in_chunk == 0) { /* if this is the 1st chunk and no pages in this chunk, * ext->oe_nr_pages must be zero, so we should be in * the other if-clause. */ LASSERT(trunc_chunk > 0); --trunc_chunk; ++chunks; } /* this is what we can free from this extent */ grants = chunks << cli->cl_chunkbits; ext->oe_grants -= grants; last_index = ((trunc_chunk + 1) << ppc_bits) - 1; ext->oe_end = min(last_index, ext->oe_max_end); LASSERT(ext->oe_end >= ext->oe_start); LASSERT(ext->oe_grants > 0); } osc_object_unlock(obj); if (grants > 0 || nr_pages > 0) osc_free_grant(cli, nr_pages, grants); out: cl_io_fini(env, io); cl_env_nested_put(&nest, env); RETURN(rc); } /** * This function is used to make the extent prepared for transfer. * A race with flusing page - ll_writepage() has to be handled cautiously. */ static int osc_extent_make_ready(const struct lu_env *env, struct osc_extent *ext) { struct osc_async_page *oap; struct osc_async_page *last = NULL; struct osc_object *obj = ext->oe_obj; int page_count = 0; int rc; ENTRY; /* we're going to grab page lock, so object lock must not be taken. */ LASSERT(sanity_check(ext) == 0); /* in locking state, any process should not touch this extent. */ EASSERT(ext->oe_state == OES_LOCKING, ext); EASSERT(ext->oe_owner != NULL, ext); OSC_EXTENT_DUMP(D_CACHE, ext, "make ready\n"); list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) { ++page_count; if (last == NULL || last->oap_obj_off < oap->oap_obj_off) last = oap; /* checking ASYNC_READY is race safe */ if ((oap->oap_async_flags & ASYNC_READY) != 0) continue; rc = osc_make_ready(env, oap, OBD_BRW_WRITE); switch (rc) { case 0: spin_lock(&oap->oap_lock); oap->oap_async_flags |= ASYNC_READY; spin_unlock(&oap->oap_lock); break; case -EALREADY: LASSERT((oap->oap_async_flags & ASYNC_READY) != 0); break; default: LASSERTF(0, "unknown return code: %d\n", rc); } } LASSERT(page_count == ext->oe_nr_pages); LASSERT(last != NULL); /* the last page is the only one we need to refresh its count by * the size of file. */ if (!(last->oap_async_flags & ASYNC_COUNT_STABLE)) { last->oap_count = osc_refresh_count(env, last, OBD_BRW_WRITE); LASSERT(last->oap_count > 0); LASSERT(last->oap_page_off + last->oap_count <= PAGE_CACHE_SIZE); spin_lock(&last->oap_lock); last->oap_async_flags |= ASYNC_COUNT_STABLE; spin_unlock(&last->oap_lock); } /* for the rest of pages, we don't need to call osf_refresh_count() * because it's known they are not the last page */ list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) { if (!(oap->oap_async_flags & ASYNC_COUNT_STABLE)) { oap->oap_count = PAGE_CACHE_SIZE - oap->oap_page_off; spin_lock(&oap->oap_lock); oap->oap_async_flags |= ASYNC_COUNT_STABLE; spin_unlock(&oap->oap_lock); } } osc_object_lock(obj); osc_extent_state_set(ext, OES_RPC); osc_object_unlock(obj); /* get a refcount for RPC. */ osc_extent_get(ext); RETURN(0); } /** * Quick and simple version of osc_extent_find(). This function is frequently * called to expand the extent for the same IO. To expand the extent, the * page index must be in the same or next chunk of ext->oe_end. */ static int osc_extent_expand(struct osc_extent *ext, pgoff_t index, int *grants) { struct osc_object *obj = ext->oe_obj; struct client_obd *cli = osc_cli(obj); struct osc_extent *next; int ppc_bits = cli->cl_chunkbits - PAGE_CACHE_SHIFT; pgoff_t chunk = index >> ppc_bits; pgoff_t end_chunk; pgoff_t end_index; int chunksize = 1 << cli->cl_chunkbits; int rc = 0; ENTRY; LASSERT(ext->oe_max_end >= index && ext->oe_start <= index); osc_object_lock(obj); LASSERT(sanity_check_nolock(ext) == 0); end_chunk = ext->oe_end >> ppc_bits; if (chunk > end_chunk + 1) GOTO(out, rc = -ERANGE); if (end_chunk >= chunk) GOTO(out, rc = 0); LASSERT(end_chunk + 1 == chunk); /* try to expand this extent to cover @index */ end_index = min(ext->oe_max_end, ((chunk + 1) << ppc_bits) - 1); next = next_extent(ext); if (next != NULL && next->oe_start <= end_index) /* complex mode - overlapped with the next extent, * this case will be handled by osc_extent_find() */ GOTO(out, rc = -EAGAIN); ext->oe_end = end_index; ext->oe_grants += chunksize; *grants -= chunksize; LASSERT(*grants >= 0); EASSERTF(osc_extent_is_overlapped(obj, ext) == 0, ext, "overlapped after expanding for %lu.\n", index); EXIT; out: osc_object_unlock(obj); RETURN(rc); } static void osc_extent_tree_dump0(int level, struct osc_object *obj, const char *func, int line) { struct osc_extent *ext; int cnt; CDEBUG(level, "Dump object %p extents at %s:%d, mppr: %u.\n", obj, func, line, osc_cli(obj)->cl_max_pages_per_rpc); /* osc_object_lock(obj); */ cnt = 1; for (ext = first_extent(obj); ext != NULL; ext = next_extent(ext)) OSC_EXTENT_DUMP(level, ext, "in tree %d.\n", cnt++); cnt = 1; list_for_each_entry(ext, &obj->oo_hp_exts, oe_link) OSC_EXTENT_DUMP(level, ext, "hp %d.\n", cnt++); cnt = 1; list_for_each_entry(ext, &obj->oo_urgent_exts, oe_link) OSC_EXTENT_DUMP(level, ext, "urgent %d.\n", cnt++); cnt = 1; list_for_each_entry(ext, &obj->oo_reading_exts, oe_link) OSC_EXTENT_DUMP(level, ext, "reading %d.\n", cnt++); /* osc_object_unlock(obj); */ } /* ------------------ osc extent end ------------------ */ static inline int osc_is_ready(struct osc_object *osc) { return !list_empty(&osc->oo_ready_item) || !list_empty(&osc->oo_hp_ready_item); } #define OSC_IO_DEBUG(OSC, STR, args...) \ CDEBUG(D_CACHE, "obj %p ready %d|%c|%c wr %d|%c|%c rd %d|%c " STR, \ (OSC), osc_is_ready(OSC), \ list_empty_marker(&(OSC)->oo_hp_ready_item), \ list_empty_marker(&(OSC)->oo_ready_item), \ atomic_read(&(OSC)->oo_nr_writes), \ list_empty_marker(&(OSC)->oo_hp_exts), \ list_empty_marker(&(OSC)->oo_urgent_exts), \ atomic_read(&(OSC)->oo_nr_reads), \ list_empty_marker(&(OSC)->oo_reading_exts), \ ##args) static int osc_make_ready(const struct lu_env *env, struct osc_async_page *oap, int cmd) { struct osc_page *opg = oap2osc_page(oap); struct cl_page *page = oap2cl_page(oap); int result; LASSERT(cmd == OBD_BRW_WRITE); /* no cached reads */ ENTRY; result = cl_page_make_ready(env, page, CRT_WRITE); if (result == 0) opg->ops_submit_time = cfs_time_current(); RETURN(result); } static int osc_refresh_count(const struct lu_env *env, struct osc_async_page *oap, int cmd) { struct osc_page *opg = oap2osc_page(oap); pgoff_t index = osc_index(oap2osc(oap)); struct cl_object *obj; struct cl_attr *attr = &osc_env_info(env)->oti_attr; int result; loff_t kms; /* readpage queues with _COUNT_STABLE, shouldn't get here. */ LASSERT(!(cmd & OBD_BRW_READ)); LASSERT(opg != NULL); obj = opg->ops_cl.cpl_obj; cl_object_attr_lock(obj); result = cl_object_attr_get(env, obj, attr); cl_object_attr_unlock(obj); if (result < 0) return result; kms = attr->cat_kms; if (cl_offset(obj, index) >= kms) /* catch race with truncate */ return 0; else if (cl_offset(obj, index + 1) > kms) /* catch sub-page write at end of file */ return kms % PAGE_CACHE_SIZE; else return PAGE_CACHE_SIZE; } static int osc_completion(const struct lu_env *env, struct osc_async_page *oap, int cmd, int rc) { struct osc_page *opg = oap2osc_page(oap); struct cl_page *page = oap2cl_page(oap); struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj); enum cl_req_type crt; int srvlock; ENTRY; cmd &= ~OBD_BRW_NOQUOTA; LASSERTF(equi(page->cp_state == CPS_PAGEIN, cmd == OBD_BRW_READ), "cp_state:%u, cmd:%d\n", page->cp_state, cmd); LASSERTF(equi(page->cp_state == CPS_PAGEOUT, cmd == OBD_BRW_WRITE), "cp_state:%u, cmd:%d\n", page->cp_state, cmd); LASSERT(opg->ops_transfer_pinned); /* * page->cp_req can be NULL if io submission failed before * cl_req was allocated. */ if (page->cp_req != NULL) cl_req_page_done(env, page); LASSERT(page->cp_req == NULL); crt = cmd == OBD_BRW_READ ? CRT_READ : CRT_WRITE; /* Clear opg->ops_transfer_pinned before VM lock is released. */ opg->ops_transfer_pinned = 0; spin_lock(&obj->oo_seatbelt); LASSERT(opg->ops_submitter != NULL); LASSERT(!list_empty(&opg->ops_inflight)); list_del_init(&opg->ops_inflight); opg->ops_submitter = NULL; spin_unlock(&obj->oo_seatbelt); opg->ops_submit_time = 0; srvlock = oap->oap_brw_flags & OBD_BRW_SRVLOCK; /* statistic */ if (rc == 0 && srvlock) { struct lu_device *ld = opg->ops_cl.cpl_obj->co_lu.lo_dev; struct osc_stats *stats = &lu2osc_dev(ld)->od_stats; int bytes = oap->oap_count; if (crt == CRT_READ) stats->os_lockless_reads += bytes; else stats->os_lockless_writes += bytes; } /* * This has to be the last operation with the page, as locks are * released in cl_page_completion() and nothing except for the * reference counter protects page from concurrent reclaim. */ lu_ref_del(&page->cp_reference, "transfer", page); cl_page_completion(env, page, crt, rc); RETURN(0); } #define OSC_DUMP_GRANT(lvl, cli, fmt, args...) do { \ struct client_obd *__tmp = (cli); \ CDEBUG(lvl, "%s: grant { dirty: %ld/%ld dirty_pages: %ld/%lu " \ "dropped: %ld avail: %ld, reserved: %ld, flight: %d }" \ "lru {in list: %ld, left: %ld, waiters: %d }" fmt, \ __tmp->cl_import->imp_obd->obd_name, \ __tmp->cl_dirty_pages, __tmp->cl_dirty_max_pages, \ atomic_long_read(&obd_dirty_pages), obd_max_dirty_pages, \ __tmp->cl_lost_grant, __tmp->cl_avail_grant, \ __tmp->cl_reserved_grant, __tmp->cl_w_in_flight, \ atomic_long_read(&__tmp->cl_lru_in_list), \ atomic_long_read(&__tmp->cl_lru_busy), \ atomic_read(&__tmp->cl_lru_shrinkers), ##args); \ } while (0) /* caller must hold loi_list_lock */ static void osc_consume_write_grant(struct client_obd *cli, struct brw_page *pga) { assert_spin_locked(&cli->cl_loi_list_lock.lock); LASSERT(!(pga->flag & OBD_BRW_FROM_GRANT)); atomic_long_inc(&obd_dirty_pages); cli->cl_dirty_pages++; pga->flag |= OBD_BRW_FROM_GRANT; CDEBUG(D_CACHE, "using %lu grant credits for brw %p page %p\n", PAGE_CACHE_SIZE, pga, pga->pg); osc_update_next_shrink(cli); } /* the companion to osc_consume_write_grant, called when a brw has completed. * must be called with the loi lock held. */ static void osc_release_write_grant(struct client_obd *cli, struct brw_page *pga) { ENTRY; assert_spin_locked(&cli->cl_loi_list_lock.lock); if (!(pga->flag & OBD_BRW_FROM_GRANT)) { EXIT; return; } pga->flag &= ~OBD_BRW_FROM_GRANT; atomic_long_dec(&obd_dirty_pages); cli->cl_dirty_pages--; if (pga->flag & OBD_BRW_NOCACHE) { pga->flag &= ~OBD_BRW_NOCACHE; atomic_long_dec(&obd_dirty_transit_pages); cli->cl_dirty_transit--; } EXIT; } /** * To avoid sleeping with object lock held, it's good for us allocate enough * grants before entering into critical section. * * client_obd_list_lock held by caller */ static int osc_reserve_grant(struct client_obd *cli, unsigned int bytes) { int rc = -EDQUOT; if (cli->cl_avail_grant >= bytes) { cli->cl_avail_grant -= bytes; cli->cl_reserved_grant += bytes; rc = 0; } return rc; } static void __osc_unreserve_grant(struct client_obd *cli, unsigned int reserved, unsigned int unused) { /* it's quite normal for us to get more grant than reserved. * Thinking about a case that two extents merged by adding a new * chunk, we can save one extent tax. If extent tax is greater than * one chunk, we can save more grant by adding a new chunk */ cli->cl_reserved_grant -= reserved; if (unused > reserved) { cli->cl_avail_grant += reserved; cli->cl_lost_grant += unused - reserved; } else { cli->cl_avail_grant += unused; } } void osc_unreserve_grant(struct client_obd *cli, unsigned int reserved, unsigned int unused) { client_obd_list_lock(&cli->cl_loi_list_lock); __osc_unreserve_grant(cli, reserved, unused); if (unused > 0) osc_wake_cache_waiters(cli); client_obd_list_unlock(&cli->cl_loi_list_lock); } /** * Free grant after IO is finished or canceled. * * @lost_grant is used to remember how many grants we have allocated but not * used, we should return these grants to OST. There're two cases where grants * can be lost: * 1. truncate; * 2. blocksize at OST is less than PAGE_CACHE_SIZE and a partial page was * written. In this case OST may use less chunks to serve this partial * write. OSTs don't actually know the page size on the client side. so * clients have to calculate lost grant by the blocksize on the OST. * See filter_grant_check() for details. */ static void osc_free_grant(struct client_obd *cli, unsigned int nr_pages, unsigned int lost_grant) { int grant = (1 << cli->cl_chunkbits) + cli->cl_extent_tax; client_obd_list_lock(&cli->cl_loi_list_lock); atomic_long_sub(nr_pages, &obd_dirty_pages); cli->cl_dirty_pages -= nr_pages; cli->cl_lost_grant += lost_grant; if (cli->cl_avail_grant < grant && cli->cl_lost_grant >= grant) { /* borrow some grant from truncate to avoid the case that * truncate uses up all avail grant */ cli->cl_lost_grant -= grant; cli->cl_avail_grant += grant; } osc_wake_cache_waiters(cli); client_obd_list_unlock(&cli->cl_loi_list_lock); CDEBUG(D_CACHE, "lost %u grant: %lu avail: %lu dirty: %lu\n", lost_grant, cli->cl_lost_grant, cli->cl_avail_grant, cli->cl_dirty_pages << PAGE_CACHE_SHIFT); } /** * The companion to osc_enter_cache(), called when @oap is no longer part of * the dirty accounting due to error. */ static void osc_exit_cache(struct client_obd *cli, struct osc_async_page *oap) { client_obd_list_lock(&cli->cl_loi_list_lock); osc_release_write_grant(cli, &oap->oap_brw_page); client_obd_list_unlock(&cli->cl_loi_list_lock); } /** * Non-blocking version of osc_enter_cache() that consumes grant only when it * is available. */ static int osc_enter_cache_try(struct client_obd *cli, struct osc_async_page *oap, int bytes, int transient) { int rc; OSC_DUMP_GRANT(D_CACHE, cli, "need:%d.\n", bytes); rc = osc_reserve_grant(cli, bytes); if (rc < 0) return 0; if (cli->cl_dirty_pages < cli->cl_dirty_max_pages && 1 + atomic_long_read(&obd_dirty_pages) <= obd_max_dirty_pages) { osc_consume_write_grant(cli, &oap->oap_brw_page); if (transient) { cli->cl_dirty_transit++; atomic_long_inc(&obd_dirty_transit_pages); oap->oap_brw_flags |= OBD_BRW_NOCACHE; } rc = 1; } else { __osc_unreserve_grant(cli, bytes, bytes); rc = 0; } return rc; } static int ocw_granted(struct client_obd *cli, struct osc_cache_waiter *ocw) { int rc; client_obd_list_lock(&cli->cl_loi_list_lock); rc = list_empty(&ocw->ocw_entry); client_obd_list_unlock(&cli->cl_loi_list_lock); return rc; } /** * The main entry to reserve dirty page accounting. Usually the grant reserved * in this function will be freed in bulk in osc_free_grant() unless it fails * to add osc cache, in that case, it will be freed in osc_exit_cache(). * * The process will be put into sleep if it's already run out of grant. */ static int osc_enter_cache(const struct lu_env *env, struct client_obd *cli, struct osc_async_page *oap, int bytes) { struct osc_object *osc = oap->oap_obj; struct lov_oinfo *loi = osc->oo_oinfo; struct osc_cache_waiter ocw; struct l_wait_info lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(600), NULL, LWI_ON_SIGNAL_NOOP, NULL); int rc = -EDQUOT; ENTRY; OSC_DUMP_GRANT(D_CACHE, cli, "need:%d.\n", bytes); client_obd_list_lock(&cli->cl_loi_list_lock); /* force the caller to try sync io. this can jump the list * of queued writes and create a discontiguous rpc stream */ if (OBD_FAIL_CHECK(OBD_FAIL_OSC_NO_GRANT) || cli->cl_dirty_max_pages == 0 || cli->cl_ar.ar_force_sync || loi->loi_ar.ar_force_sync) GOTO(out, rc = -EDQUOT); /* Hopefully normal case - cache space and write credits available */ if (osc_enter_cache_try(cli, oap, bytes, 0)) GOTO(out, rc = 0); /* We can get here for two reasons: too many dirty pages in cache, or * run out of grants. In both cases we should write dirty pages out. * Adding a cache waiter will trigger urgent write-out no matter what * RPC size will be. * The exiting condition is no avail grants and no dirty pages caching, * that really means there is no space on the OST. */ init_waitqueue_head(&ocw.ocw_waitq); ocw.ocw_oap = oap; ocw.ocw_grant = bytes; while (cli->cl_dirty_pages > 0 || cli->cl_w_in_flight > 0) { list_add_tail(&ocw.ocw_entry, &cli->cl_cache_waiters); ocw.ocw_rc = 0; client_obd_list_unlock(&cli->cl_loi_list_lock); osc_io_unplug_async(env, cli, NULL); CDEBUG(D_CACHE, "%s: sleeping for cache space @ %p for %p\n", cli->cl_import->imp_obd->obd_name, &ocw, oap); rc = l_wait_event(ocw.ocw_waitq, ocw_granted(cli, &ocw), &lwi); client_obd_list_lock(&cli->cl_loi_list_lock); /* l_wait_event is interrupted by signal, or timed out */ if (rc < 0) { switch (rc) { case -ETIMEDOUT: OSC_DUMP_GRANT(D_ERROR, cli, "try to reserve %d.\n", bytes); osc_extent_tree_dump(D_ERROR, osc); rc = -EDQUOT; break; case -EINTR: /* Ensures restartability - LU-3581 */ rc = -ERESTARTSYS; break; default: CDEBUG(D_CACHE, "%s: event for cache space @" " %p never arrived due to %d\n", cli->cl_import->imp_obd->obd_name, &ocw, rc); break; } list_del_init(&ocw.ocw_entry); GOTO(out, rc); } LASSERT(list_empty(&ocw.ocw_entry)); rc = ocw.ocw_rc; if (rc != -EDQUOT) GOTO(out, rc); if (osc_enter_cache_try(cli, oap, bytes, 0)) GOTO(out, rc = 0); } EXIT; out: client_obd_list_unlock(&cli->cl_loi_list_lock); OSC_DUMP_GRANT(D_CACHE, cli, "returned %d.\n", rc); RETURN(rc); } /* caller must hold loi_list_lock */ void osc_wake_cache_waiters(struct client_obd *cli) { struct list_head *l, *tmp; struct osc_cache_waiter *ocw; ENTRY; list_for_each_safe(l, tmp, &cli->cl_cache_waiters) { ocw = list_entry(l, struct osc_cache_waiter, ocw_entry); list_del_init(&ocw->ocw_entry); ocw->ocw_rc = -EDQUOT; /* we can't dirty more */ if ((cli->cl_dirty_pages >= cli->cl_dirty_max_pages) || (1 + atomic_long_read(&obd_dirty_pages) > obd_max_dirty_pages)) { CDEBUG(D_CACHE, "no dirty room: dirty: %ld " "osc max %ld, sys max %ld\n", cli->cl_dirty_pages, cli->cl_dirty_max_pages, obd_max_dirty_pages); goto wakeup; } ocw->ocw_rc = 0; if (!osc_enter_cache_try(cli, ocw->ocw_oap, ocw->ocw_grant, 0)) ocw->ocw_rc = -EDQUOT; wakeup: CDEBUG(D_CACHE, "wake up %p for oap %p, avail grant %ld, %d\n", ocw, ocw->ocw_oap, cli->cl_avail_grant, ocw->ocw_rc); wake_up(&ocw->ocw_waitq); } EXIT; } static int osc_max_rpc_in_flight(struct client_obd *cli, struct osc_object *osc) { int hprpc = !!list_empty(&osc->oo_hp_exts); return rpcs_in_flight(cli) >= cli->cl_max_rpcs_in_flight + hprpc; } /* This maintains the lists of pending pages to read/write for a given object * (lop). This is used by osc_check_rpcs->osc_next_obj() and osc_list_maint() * to quickly find objects that are ready to send an RPC. */ static int osc_makes_rpc(struct client_obd *cli, struct osc_object *osc, int cmd) { int invalid_import = 0; ENTRY; /* if we have an invalid import we want to drain the queued pages * by forcing them through rpcs that immediately fail and complete * the pages. recovery relies on this to empty the queued pages * before canceling the locks and evicting down the llite pages */ if ((cli->cl_import == NULL || cli->cl_import->imp_invalid)) invalid_import = 1; if (cmd & OBD_BRW_WRITE) { if (atomic_read(&osc->oo_nr_writes) == 0) RETURN(0); if (invalid_import) { CDEBUG(D_CACHE, "invalid import forcing RPC\n"); RETURN(1); } if (!list_empty(&osc->oo_hp_exts)) { CDEBUG(D_CACHE, "high prio request forcing RPC\n"); RETURN(1); } if (!list_empty(&osc->oo_urgent_exts)) { CDEBUG(D_CACHE, "urgent request forcing RPC\n"); RETURN(1); } /* trigger a write rpc stream as long as there are dirtiers * waiting for space. as they're waiting, they're not going to * create more pages to coalesce with what's waiting.. */ if (!list_empty(&cli->cl_cache_waiters)) { CDEBUG(D_CACHE, "cache waiters forcing RPC\n"); RETURN(1); } if (atomic_read(&osc->oo_nr_writes) >= cli->cl_max_pages_per_rpc) RETURN(1); } else { if (atomic_read(&osc->oo_nr_reads) == 0) RETURN(0); if (invalid_import) { CDEBUG(D_CACHE, "invalid import forcing RPC\n"); RETURN(1); } /* all read are urgent. */ if (!list_empty(&osc->oo_reading_exts)) RETURN(1); } RETURN(0); } static void osc_update_pending(struct osc_object *obj, int cmd, int delta) { struct client_obd *cli = osc_cli(obj); if (cmd & OBD_BRW_WRITE) { atomic_add(delta, &obj->oo_nr_writes); atomic_add(delta, &cli->cl_pending_w_pages); LASSERT(atomic_read(&obj->oo_nr_writes) >= 0); } else { atomic_add(delta, &obj->oo_nr_reads); atomic_add(delta, &cli->cl_pending_r_pages); LASSERT(atomic_read(&obj->oo_nr_reads) >= 0); } OSC_IO_DEBUG(obj, "update pending cmd %d delta %d.\n", cmd, delta); } static int osc_makes_hprpc(struct osc_object *obj) { return !list_empty(&obj->oo_hp_exts); } static void on_list(struct list_head *item, struct list_head *list, int should_be_on) { if (list_empty(item) && should_be_on) list_add_tail(item, list); else if (!list_empty(item) && !should_be_on) list_del_init(item); } /* maintain the osc's cli list membership invariants so that osc_send_oap_rpc * can find pages to build into rpcs quickly */ static int __osc_list_maint(struct client_obd *cli, struct osc_object *osc) { if (osc_makes_hprpc(osc)) { /* HP rpc */ on_list(&osc->oo_ready_item, &cli->cl_loi_ready_list, 0); on_list(&osc->oo_hp_ready_item, &cli->cl_loi_hp_ready_list, 1); } else { on_list(&osc->oo_hp_ready_item, &cli->cl_loi_hp_ready_list, 0); on_list(&osc->oo_ready_item, &cli->cl_loi_ready_list, osc_makes_rpc(cli, osc, OBD_BRW_WRITE) || osc_makes_rpc(cli, osc, OBD_BRW_READ)); } on_list(&osc->oo_write_item, &cli->cl_loi_write_list, atomic_read(&osc->oo_nr_writes) > 0); on_list(&osc->oo_read_item, &cli->cl_loi_read_list, atomic_read(&osc->oo_nr_reads) > 0); return osc_is_ready(osc); } static int osc_list_maint(struct client_obd *cli, struct osc_object *osc) { int is_ready; client_obd_list_lock(&cli->cl_loi_list_lock); is_ready = __osc_list_maint(cli, osc); client_obd_list_unlock(&cli->cl_loi_list_lock); return is_ready; } /* this is trying to propogate async writeback errors back up to the * application. As an async write fails we record the error code for later if * the app does an fsync. As long as errors persist we force future rpcs to be * sync so that the app can get a sync error and break the cycle of queueing * pages for which writeback will fail. */ static void osc_process_ar(struct osc_async_rc *ar, __u64 xid, int rc) { if (rc) { if (!ar->ar_rc) ar->ar_rc = rc; ar->ar_force_sync = 1; ar->ar_min_xid = ptlrpc_sample_next_xid(); return; } if (ar->ar_force_sync && (xid >= ar->ar_min_xid)) ar->ar_force_sync = 0; } /* this must be called holding the loi list lock to give coverage to exit_cache, * async_flag maintenance, and oap_request */ static void osc_ap_completion(const struct lu_env *env, struct client_obd *cli, struct osc_async_page *oap, int sent, int rc) { struct osc_object *osc = oap->oap_obj; struct lov_oinfo *loi = osc->oo_oinfo; __u64 xid = 0; ENTRY; if (oap->oap_request != NULL) { xid = ptlrpc_req_xid(oap->oap_request); ptlrpc_req_finished(oap->oap_request); oap->oap_request = NULL; } /* As the transfer for this page is being done, clear the flags */ spin_lock(&oap->oap_lock); oap->oap_async_flags = 0; spin_unlock(&oap->oap_lock); oap->oap_interrupted = 0; if (oap->oap_cmd & OBD_BRW_WRITE && xid > 0) { client_obd_list_lock(&cli->cl_loi_list_lock); osc_process_ar(&cli->cl_ar, xid, rc); osc_process_ar(&loi->loi_ar, xid, rc); client_obd_list_unlock(&cli->cl_loi_list_lock); } rc = osc_completion(env, oap, oap->oap_cmd, rc); if (rc) CERROR("completion on oap %p obj %p returns %d.\n", oap, osc, rc); EXIT; } /** * Try to add extent to one RPC. We need to think about the following things: * - # of pages must not be over max_pages_per_rpc * - extent must be compatible with previous ones */ static int try_to_add_extent_for_io(struct client_obd *cli, struct osc_extent *ext, struct list_head *rpclist, int *pc, unsigned int *max_pages) { struct osc_extent *tmp; struct osc_async_page *oap = list_first_entry(&ext->oe_pages, struct osc_async_page, oap_pending_item); ENTRY; EASSERT((ext->oe_state == OES_CACHE || ext->oe_state == OES_LOCK_DONE), ext); *max_pages = max(ext->oe_mppr, *max_pages); if (*pc + ext->oe_nr_pages > *max_pages) RETURN(0); list_for_each_entry(tmp, rpclist, oe_link) { struct osc_async_page *oap2; oap2 = list_first_entry(&tmp->oe_pages, struct osc_async_page, oap_pending_item); EASSERT(tmp->oe_owner == current, tmp); #if 0 if (overlapped(tmp, ext)) { OSC_EXTENT_DUMP(D_ERROR, tmp, "overlapped %p.\n", ext); EASSERT(0, ext); } #endif if (oap2cl_page(oap)->cp_type != oap2cl_page(oap2)->cp_type) { CDEBUG(D_CACHE, "Do not permit different type of IO" " for a same RPC\n"); RETURN(0); } if (tmp->oe_srvlock != ext->oe_srvlock || !tmp->oe_grants != !ext->oe_grants) RETURN(0); /* remove break for strict check */ break; } *pc += ext->oe_nr_pages; list_move_tail(&ext->oe_link, rpclist); ext->oe_owner = current; RETURN(1); } /** * In order to prevent multiple ptlrpcd from breaking contiguous extents, * get_write_extent() takes all appropriate extents in atomic. * * The following policy is used to collect extents for IO: * 1. Add as many HP extents as possible; * 2. Add the first urgent extent in urgent extent list and take it out of * urgent list; * 3. Add subsequent extents of this urgent extent; * 4. If urgent list is not empty, goto 2; * 5. Traverse the extent tree from the 1st extent; * 6. Above steps exit if there is no space in this RPC. */ static int get_write_extents(struct osc_object *obj, struct list_head *rpclist) { struct client_obd *cli = osc_cli(obj); struct osc_extent *ext; int page_count = 0; unsigned int max_pages = cli->cl_max_pages_per_rpc; LASSERT(osc_object_is_locked(obj)); while (!list_empty(&obj->oo_hp_exts)) { ext = list_entry(obj->oo_hp_exts.next, struct osc_extent, oe_link); LASSERT(ext->oe_state == OES_CACHE); if (!try_to_add_extent_for_io(cli, ext, rpclist, &page_count, &max_pages)) return page_count; EASSERT(ext->oe_nr_pages <= max_pages, ext); } if (page_count == max_pages) return page_count; while (!list_empty(&obj->oo_urgent_exts)) { ext = list_entry(obj->oo_urgent_exts.next, struct osc_extent, oe_link); if (!try_to_add_extent_for_io(cli, ext, rpclist, &page_count, &max_pages)) return page_count; if (!ext->oe_intree) continue; while ((ext = next_extent(ext)) != NULL) { if ((ext->oe_state != OES_CACHE) || (!list_empty(&ext->oe_link) && ext->oe_owner != NULL)) continue; if (!try_to_add_extent_for_io(cli, ext, rpclist, &page_count, &max_pages)) return page_count; } } if (page_count == max_pages) return page_count; ext = first_extent(obj); while (ext != NULL) { if ((ext->oe_state != OES_CACHE) || /* this extent may be already in current rpclist */ (!list_empty(&ext->oe_link) && ext->oe_owner != NULL)) { ext = next_extent(ext); continue; } if (!try_to_add_extent_for_io(cli, ext, rpclist, &page_count, &max_pages)) return page_count; ext = next_extent(ext); } return page_count; } static int osc_send_write_rpc(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc, pdl_policy_t pol) __must_hold(osc) { struct list_head rpclist = LIST_HEAD_INIT(rpclist); struct osc_extent *ext; struct osc_extent *tmp; struct osc_extent *first = NULL; obd_count page_count = 0; int srvlock = 0; int rc = 0; ENTRY; LASSERT(osc_object_is_locked(osc)); page_count = get_write_extents(osc, &rpclist); LASSERT(equi(page_count == 0, list_empty(&rpclist))); if (list_empty(&rpclist)) RETURN(0); osc_update_pending(osc, OBD_BRW_WRITE, -page_count); list_for_each_entry(ext, &rpclist, oe_link) { LASSERT(ext->oe_state == OES_CACHE || ext->oe_state == OES_LOCK_DONE); if (ext->oe_state == OES_CACHE) osc_extent_state_set(ext, OES_LOCKING); else osc_extent_state_set(ext, OES_RPC); } /* we're going to grab page lock, so release object lock because * lock order is page lock -> object lock. */ osc_object_unlock(osc); list_for_each_entry_safe(ext, tmp, &rpclist, oe_link) { if (ext->oe_state == OES_LOCKING) { rc = osc_extent_make_ready(env, ext); if (unlikely(rc < 0)) { list_del_init(&ext->oe_link); osc_extent_finish(env, ext, 0, rc); continue; } } if (first == NULL) { first = ext; srvlock = ext->oe_srvlock; } else { LASSERT(srvlock == ext->oe_srvlock); } } if (!list_empty(&rpclist)) { LASSERT(page_count > 0); rc = osc_build_rpc(env, cli, &rpclist, OBD_BRW_WRITE, pol); LASSERT(list_empty(&rpclist)); } osc_object_lock(osc); RETURN(rc); } /** * prepare pages for ASYNC io and put pages in send queue. * * \param cmd OBD_BRW_* macroses * \param lop pending pages * * \return zero if no page added to send queue. * \return 1 if pages successfully added to send queue. * \return negative on errors. */ static int osc_send_read_rpc(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc, pdl_policy_t pol) __must_hold(osc) { struct osc_extent *ext; struct osc_extent *next; struct list_head rpclist = LIST_HEAD_INIT(rpclist); int page_count = 0; unsigned int max_pages = cli->cl_max_pages_per_rpc; int rc = 0; ENTRY; LASSERT(osc_object_is_locked(osc)); list_for_each_entry_safe(ext, next, &osc->oo_reading_exts, oe_link) { EASSERT(ext->oe_state == OES_LOCK_DONE, ext); if (!try_to_add_extent_for_io(cli, ext, &rpclist, &page_count, &max_pages)) break; osc_extent_state_set(ext, OES_RPC); EASSERT(ext->oe_nr_pages <= max_pages, ext); } LASSERT(page_count <= max_pages); osc_update_pending(osc, OBD_BRW_READ, -page_count); if (!list_empty(&rpclist)) { osc_object_unlock(osc); LASSERT(page_count > 0); rc = osc_build_rpc(env, cli, &rpclist, OBD_BRW_READ, pol); LASSERT(list_empty(&rpclist)); osc_object_lock(osc); } RETURN(rc); } #define list_to_obj(list, item) ({ \ struct list_head *__tmp = (list)->next; \ list_del_init(__tmp); \ list_entry(__tmp, struct osc_object, oo_##item); \ }) /* This is called by osc_check_rpcs() to find which objects have pages that * we could be sending. These lists are maintained by osc_makes_rpc(). */ static struct osc_object *osc_next_obj(struct client_obd *cli) { ENTRY; /* First return objects that have blocked locks so that they * will be flushed quickly and other clients can get the lock, * then objects which have pages ready to be stuffed into RPCs */ if (!list_empty(&cli->cl_loi_hp_ready_list)) RETURN(list_to_obj(&cli->cl_loi_hp_ready_list, hp_ready_item)); if (!list_empty(&cli->cl_loi_ready_list)) RETURN(list_to_obj(&cli->cl_loi_ready_list, ready_item)); /* then if we have cache waiters, return all objects with queued * writes. This is especially important when many small files * have filled up the cache and not been fired into rpcs because * they don't pass the nr_pending/object threshhold */ if (!list_empty(&cli->cl_cache_waiters) && !list_empty(&cli->cl_loi_write_list)) RETURN(list_to_obj(&cli->cl_loi_write_list, write_item)); /* then return all queued objects when we have an invalid import * so that they get flushed */ if (cli->cl_import == NULL || cli->cl_import->imp_invalid) { if (!list_empty(&cli->cl_loi_write_list)) RETURN(list_to_obj(&cli->cl_loi_write_list, write_item)); if (!list_empty(&cli->cl_loi_read_list)) RETURN(list_to_obj(&cli->cl_loi_read_list, read_item)); } RETURN(NULL); } /* called with the loi list lock held */ static void osc_check_rpcs(const struct lu_env *env, struct client_obd *cli, pdl_policy_t pol) __must_hold(&cli->cl_loi_list_lock) { struct osc_object *osc; int rc = 0; ENTRY; while ((osc = osc_next_obj(cli)) != NULL) { struct cl_object *obj = osc2cl(osc); struct lu_ref_link link; OSC_IO_DEBUG(osc, "%lu in flight\n", rpcs_in_flight(cli)); if (osc_max_rpc_in_flight(cli, osc)) { __osc_list_maint(cli, osc); break; } cl_object_get(obj); client_obd_list_unlock(&cli->cl_loi_list_lock); lu_object_ref_add_at(&obj->co_lu, &link, "check", current); /* attempt some read/write balancing by alternating between * reads and writes in an object. The makes_rpc checks here * would be redundant if we were getting read/write work items * instead of objects. we don't want send_oap_rpc to drain a * partial read pending queue when we're given this object to * do io on writes while there are cache waiters */ osc_object_lock(osc); if (osc_makes_rpc(cli, osc, OBD_BRW_WRITE)) { rc = osc_send_write_rpc(env, cli, osc, pol); if (rc < 0) { CERROR("Write request failed with %d\n", rc); /* osc_send_write_rpc failed, mostly because of * memory pressure. * * It can't break here, because if: * - a page was submitted by osc_io_submit, so * page locked; * - no request in flight * - no subsequent request * The system will be in live-lock state, * because there is no chance to call * osc_io_unplug() and osc_check_rpcs() any * more. pdflush can't help in this case, * because it might be blocked at grabbing * the page lock as we mentioned. * * Anyway, continue to drain pages. */ /* break; */ } } if (osc_makes_rpc(cli, osc, OBD_BRW_READ)) { rc = osc_send_read_rpc(env, cli, osc, pol); if (rc < 0) CERROR("Read request failed with %d\n", rc); } osc_object_unlock(osc); osc_list_maint(cli, osc); lu_object_ref_del_at(&obj->co_lu, &link, "check", current); cl_object_put(env, obj); client_obd_list_lock(&cli->cl_loi_list_lock); } } static int osc_io_unplug0(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc, pdl_policy_t pol, int async) { int rc = 0; if (osc != NULL && osc_list_maint(cli, osc) == 0) return 0; if (!async) { /* disable osc_lru_shrink() temporarily to avoid * potential stack overrun problem. LU-2859 */ atomic_inc(&cli->cl_lru_shrinkers); client_obd_list_lock(&cli->cl_loi_list_lock); osc_check_rpcs(env, cli, pol); client_obd_list_unlock(&cli->cl_loi_list_lock); atomic_dec(&cli->cl_lru_shrinkers); } else { CDEBUG(D_CACHE, "Queue writeback work for client %p.\n", cli); LASSERT(cli->cl_writeback_work != NULL); rc = ptlrpcd_queue_work(cli->cl_writeback_work); } return rc; } static int osc_io_unplug_async(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc) { /* XXX: policy is no use actually. */ return osc_io_unplug0(env, cli, osc, PDL_POLICY_ROUND, 1); } void osc_io_unplug(const struct lu_env *env, struct client_obd *cli, struct osc_object *osc, pdl_policy_t pol) { (void)osc_io_unplug0(env, cli, osc, pol, 0); } int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops, struct page *page, loff_t offset) { struct obd_export *exp = osc_export(osc); struct osc_async_page *oap = &ops->ops_oap; ENTRY; if (!page) return cfs_size_round(sizeof(*oap)); oap->oap_magic = OAP_MAGIC; oap->oap_cli = &exp->exp_obd->u.cli; oap->oap_obj = osc; oap->oap_page = page; oap->oap_obj_off = offset; LASSERT(!(offset & ~CFS_PAGE_MASK)); if (!client_is_remote(exp) && cfs_capable(CFS_CAP_SYS_RESOURCE)) oap->oap_brw_flags = OBD_BRW_NOQUOTA; INIT_LIST_HEAD(&oap->oap_pending_item); INIT_LIST_HEAD(&oap->oap_rpc_item); spin_lock_init(&oap->oap_lock); CDEBUG(D_INFO, "oap %p page %p obj off "LPU64"\n", oap, page, oap->oap_obj_off); RETURN(0); } int osc_queue_async_io(const struct lu_env *env, struct cl_io *io, struct osc_page *ops) { struct osc_io *oio = osc_env_io(env); struct osc_extent *ext = NULL; struct osc_async_page *oap = &ops->ops_oap; struct client_obd *cli = oap->oap_cli; struct osc_object *osc = oap->oap_obj; pgoff_t index; int grants = 0; int brw_flags = OBD_BRW_ASYNC; int cmd = OBD_BRW_WRITE; int need_release = 0; int rc = 0; ENTRY; if (oap->oap_magic != OAP_MAGIC) RETURN(-EINVAL); if (cli->cl_import == NULL || cli->cl_import->imp_invalid) RETURN(-EIO); if (!list_empty(&oap->oap_pending_item) || !list_empty(&oap->oap_rpc_item)) RETURN(-EBUSY); /* Set the OBD_BRW_SRVLOCK before the page is queued. */ brw_flags |= ops->ops_srvlock ? OBD_BRW_SRVLOCK : 0; if (!client_is_remote(osc_export(osc)) && cfs_capable(CFS_CAP_SYS_RESOURCE)) { brw_flags |= OBD_BRW_NOQUOTA; cmd |= OBD_BRW_NOQUOTA; } /* check if the file's owner/group is over quota */ if (!(cmd & OBD_BRW_NOQUOTA)) { struct cl_object *obj; struct cl_attr *attr; unsigned int qid[MAXQUOTAS]; obj = cl_object_top(&osc->oo_cl); attr = &osc_env_info(env)->oti_attr; cl_object_attr_lock(obj); rc = cl_object_attr_get(env, obj, attr); cl_object_attr_unlock(obj); qid[USRQUOTA] = attr->cat_uid; qid[GRPQUOTA] = attr->cat_gid; if (rc == 0 && osc_quota_chkdq(cli, qid) == NO_QUOTA) rc = -EDQUOT; if (rc) RETURN(rc); } oap->oap_cmd = cmd; oap->oap_page_off = ops->ops_from; oap->oap_count = ops->ops_to - ops->ops_from; /* No need to hold a lock here, * since this page is not in any list yet. */ oap->oap_async_flags = 0; oap->oap_brw_flags = brw_flags; OSC_IO_DEBUG(osc, "oap %p page %p added for cmd %d\n", oap, oap->oap_page, oap->oap_cmd & OBD_BRW_RWMASK); index = osc_index(oap2osc(oap)); /* Add this page into extent by the following steps: * 1. if there exists an active extent for this IO, mostly this page * can be added to the active extent and sometimes we need to * expand extent to accomodate this page; * 2. otherwise, a new extent will be allocated. */ ext = oio->oi_active; if (ext != NULL && ext->oe_start <= index && ext->oe_max_end >= index) { /* one chunk plus extent overhead must be enough to write this * page */ grants = (1 << cli->cl_chunkbits) + cli->cl_extent_tax; if (ext->oe_end >= index) grants = 0; /* it doesn't need any grant to dirty this page */ client_obd_list_lock(&cli->cl_loi_list_lock); rc = osc_enter_cache_try(cli, oap, grants, 0); client_obd_list_unlock(&cli->cl_loi_list_lock); if (rc == 0) { /* try failed */ grants = 0; need_release = 1; } else if (ext->oe_end < index) { int tmp = grants; /* try to expand this extent */ rc = osc_extent_expand(ext, index, &tmp); if (rc < 0) { need_release = 1; /* don't free reserved grant */ } else { OSC_EXTENT_DUMP(D_CACHE, ext, "expanded for %lu.\n", index); osc_unreserve_grant(cli, grants, tmp); grants = 0; } } rc = 0; } else if (ext != NULL) { /* index is located outside of active extent */ need_release = 1; } if (need_release) { osc_extent_release(env, ext); oio->oi_active = NULL; ext = NULL; } if (ext == NULL) { int tmp = (1 << cli->cl_chunkbits) + cli->cl_extent_tax; /* try to find new extent to cover this page */ LASSERT(oio->oi_active == NULL); /* we may have allocated grant for this page if we failed * to expand the previous active extent. */ LASSERT(ergo(grants > 0, grants >= tmp)); rc = 0; if (grants == 0) { /* we haven't allocated grant for this page. */ rc = osc_enter_cache(env, cli, oap, tmp); if (rc == 0) grants = tmp; } tmp = grants; if (rc == 0) { ext = osc_extent_find(env, osc, index, &tmp); if (IS_ERR(ext)) { LASSERT(tmp == grants); osc_exit_cache(cli, oap); rc = PTR_ERR(ext); ext = NULL; } else { oio->oi_active = ext; } } if (grants > 0) osc_unreserve_grant(cli, grants, tmp); } LASSERT(ergo(rc == 0, ext != NULL)); if (ext != NULL) { EASSERTF(ext->oe_end >= index && ext->oe_start <= index, ext, "index = %lu.\n", index); LASSERT((oap->oap_brw_flags & OBD_BRW_FROM_GRANT) != 0); osc_object_lock(osc); if (ext->oe_nr_pages == 0) ext->oe_srvlock = ops->ops_srvlock; else LASSERT(ext->oe_srvlock == ops->ops_srvlock); ++ext->oe_nr_pages; list_add_tail(&oap->oap_pending_item, &ext->oe_pages); osc_object_unlock(osc); } RETURN(rc); } int osc_teardown_async_page(const struct lu_env *env, struct osc_object *obj, struct osc_page *ops) { struct osc_async_page *oap = &ops->ops_oap; struct osc_extent *ext = NULL; int rc = 0; ENTRY; LASSERT(oap->oap_magic == OAP_MAGIC); CDEBUG(D_INFO, "teardown oap %p page %p at index %lu.\n", oap, ops, osc_index(oap2osc(oap))); osc_object_lock(obj); if (!list_empty(&oap->oap_rpc_item)) { CDEBUG(D_CACHE, "oap %p is not in cache.\n", oap); rc = -EBUSY; } else if (!list_empty(&oap->oap_pending_item)) { ext = osc_extent_lookup(obj, osc_index(oap2osc(oap))); /* only truncated pages are allowed to be taken out. * See osc_extent_truncate() and osc_cache_truncate_start() * for details. */ if (ext != NULL && ext->oe_state != OES_TRUNC) { OSC_EXTENT_DUMP(D_ERROR, ext, "trunc at %lu.\n", osc_index(oap2osc(oap))); rc = -EBUSY; } } osc_object_unlock(obj); if (ext != NULL) osc_extent_put(env, ext); RETURN(rc); } /** * This is called when a page is picked up by kernel to write out. * * We should find out the corresponding extent and add the whole extent * into urgent list. The extent may be being truncated or used, handle it * carefully. */ int osc_flush_async_page(const struct lu_env *env, struct cl_io *io, struct osc_page *ops) { struct osc_extent *ext = NULL; struct osc_object *obj = cl2osc(ops->ops_cl.cpl_obj); struct cl_page *cp = ops->ops_cl.cpl_page; pgoff_t index = osc_index(ops); struct osc_async_page *oap = &ops->ops_oap; bool unplug = false; int rc = 0; ENTRY; osc_object_lock(obj); ext = osc_extent_lookup(obj, index); if (ext == NULL) { osc_extent_tree_dump(D_ERROR, obj); LASSERTF(0, "page index %lu is NOT covered.\n", index); } switch (ext->oe_state) { case OES_RPC: case OES_LOCK_DONE: CL_PAGE_DEBUG(D_ERROR, env, cp, "flush an in-rpc page?\n"); LASSERT(0); break; case OES_LOCKING: /* If we know this extent is being written out, we should abort * so that the writer can make this page ready. Otherwise, there * exists a deadlock problem because other process can wait for * page writeback bit holding page lock; and meanwhile in * vvp_page_make_ready(), we need to grab page lock before * really sending the RPC. */ case OES_TRUNC: /* race with truncate, page will be redirtied */ case OES_ACTIVE: /* The extent is active so we need to abort and let the caller * re-dirty the page. If we continued on here, and we were the * one making the extent active, we could deadlock waiting for * the page writeback to clear but it won't because the extent * is active and won't be written out. */ GOTO(out, rc = -EAGAIN); default: break; } rc = cl_page_prep(env, io, cp, CRT_WRITE); if (rc) GOTO(out, rc); spin_lock(&oap->oap_lock); oap->oap_async_flags |= ASYNC_READY|ASYNC_URGENT; spin_unlock(&oap->oap_lock); if (memory_pressure_get()) ext->oe_memalloc = 1; ext->oe_urgent = 1; if (ext->oe_state == OES_CACHE) { OSC_EXTENT_DUMP(D_CACHE, ext, "flush page %p make it urgent.\n", oap); if (list_empty(&ext->oe_link)) list_add_tail(&ext->oe_link, &obj->oo_urgent_exts); unplug = true; } rc = 0; EXIT; out: osc_object_unlock(obj); osc_extent_put(env, ext); if (unplug) osc_io_unplug_async(env, osc_cli(obj), obj); return rc; } /** * this is called when a sync waiter receives an interruption. Its job is to * get the caller woken as soon as possible. If its page hasn't been put in an * rpc yet it can dequeue immediately. Otherwise it has to mark the rpc as * desiring interruption which will forcefully complete the rpc once the rpc * has timed out. */ int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops) { struct osc_async_page *oap = &ops->ops_oap; struct osc_object *obj = oap->oap_obj; struct client_obd *cli = osc_cli(obj); struct osc_extent *ext; struct osc_extent *found = NULL; struct list_head *plist; pgoff_t index = osc_index(ops); int rc = -EBUSY; int cmd; ENTRY; LASSERT(!oap->oap_interrupted); oap->oap_interrupted = 1; /* Find out the caching extent */ osc_object_lock(obj); if (oap->oap_cmd & OBD_BRW_WRITE) { plist = &obj->oo_urgent_exts; cmd = OBD_BRW_WRITE; } else { plist = &obj->oo_reading_exts; cmd = OBD_BRW_READ; } list_for_each_entry(ext, plist, oe_link) { if (ext->oe_start <= index && ext->oe_end >= index) { LASSERT(ext->oe_state == OES_LOCK_DONE); /* For OES_LOCK_DONE state extent, it has already held * a refcount for RPC. */ found = osc_extent_get(ext); break; } } if (found != NULL) { list_del_init(&found->oe_link); osc_update_pending(obj, cmd, -found->oe_nr_pages); osc_object_unlock(obj); osc_extent_finish(env, found, 0, -EINTR); osc_extent_put(env, found); rc = 0; } else { osc_object_unlock(obj); /* ok, it's been put in an rpc. only one oap gets a request * reference */ if (oap->oap_request != NULL) { ptlrpc_mark_interrupted(oap->oap_request); ptlrpcd_wake(oap->oap_request); ptlrpc_req_finished(oap->oap_request); oap->oap_request = NULL; } } osc_list_maint(cli, obj); RETURN(rc); } int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj, struct list_head *list, int cmd, int brw_flags) { struct client_obd *cli = osc_cli(obj); struct osc_extent *ext; struct osc_async_page *oap; int page_count = 0; int mppr = cli->cl_max_pages_per_rpc; pgoff_t start = CL_PAGE_EOF; pgoff_t end = 0; ENTRY; list_for_each_entry(oap, list, oap_pending_item) { pgoff_t index = osc_index(oap2osc(oap)); if (index > end) end = index; if (index < start) start = index; ++page_count; mppr <<= (page_count > mppr); } ext = osc_extent_alloc(obj); if (ext == NULL) { list_for_each_entry(oap, list, oap_pending_item) { list_del_init(&oap->oap_pending_item); osc_ap_completion(env, cli, oap, 0, -ENOMEM); } RETURN(-ENOMEM); } ext->oe_rw = !!(cmd & OBD_BRW_READ); ext->oe_urgent = 1; ext->oe_start = start; ext->oe_end = ext->oe_max_end = end; ext->oe_obj = obj; ext->oe_srvlock = !!(brw_flags & OBD_BRW_SRVLOCK); ext->oe_nr_pages = page_count; ext->oe_mppr = mppr; list_splice_init(list, &ext->oe_pages); osc_object_lock(obj); /* Reuse the initial refcount for RPC, don't drop it */ osc_extent_state_set(ext, OES_LOCK_DONE); if (cmd & OBD_BRW_WRITE) { list_add_tail(&ext->oe_link, &obj->oo_urgent_exts); osc_update_pending(obj, OBD_BRW_WRITE, page_count); } else { list_add_tail(&ext->oe_link, &obj->oo_reading_exts); osc_update_pending(obj, OBD_BRW_READ, page_count); } osc_object_unlock(obj); osc_io_unplug_async(env, cli, obj); RETURN(0); } /** * Called by osc_io_setattr_start() to freeze and destroy covering extents. */ int osc_cache_truncate_start(const struct lu_env *env, struct osc_io *oio, struct osc_object *obj, __u64 size) { struct client_obd *cli = osc_cli(obj); struct osc_extent *ext; struct osc_extent *waiting = NULL; pgoff_t index; struct list_head list = LIST_HEAD_INIT(list); int result = 0; bool partial; ENTRY; /* pages with index greater or equal to index will be truncated. */ index = cl_index(osc2cl(obj), size); partial = size > cl_offset(osc2cl(obj), index); again: osc_object_lock(obj); ext = osc_extent_search(obj, index); if (ext == NULL) ext = first_extent(obj); else if (ext->oe_end < index) ext = next_extent(ext); while (ext != NULL) { EASSERT(ext->oe_state != OES_TRUNC, ext); if (ext->oe_state > OES_CACHE || ext->oe_urgent) { /* if ext is in urgent state, it means there must exist * a page already having been flushed by write_page(). * We have to wait for this extent because we can't * truncate that page. */ LASSERT(!ext->oe_hp); OSC_EXTENT_DUMP(D_CACHE, ext, "waiting for busy extent\n"); waiting = osc_extent_get(ext); break; } OSC_EXTENT_DUMP(D_CACHE, ext, "try to trunc:"LPU64".\n", size); osc_extent_get(ext); if (ext->oe_state == OES_ACTIVE) { /* though we grab inode mutex for write path, but we * release it before releasing extent(in osc_io_end()), * so there is a race window that an extent is still * in OES_ACTIVE when truncate starts. */ LASSERT(!ext->oe_trunc_pending); ext->oe_trunc_pending = 1; } else { EASSERT(ext->oe_state == OES_CACHE, ext); osc_extent_state_set(ext, OES_TRUNC); osc_update_pending(obj, OBD_BRW_WRITE, -ext->oe_nr_pages); } EASSERT(list_empty(&ext->oe_link), ext); list_add_tail(&ext->oe_link, &list); ext = next_extent(ext); } osc_object_unlock(obj); osc_list_maint(cli, obj); while (!list_empty(&list)) { int rc; ext = list_entry(list.next, struct osc_extent, oe_link); list_del_init(&ext->oe_link); /* extent may be in OES_ACTIVE state because inode mutex * is released before osc_io_end() in file write case */ if (ext->oe_state != OES_TRUNC) osc_extent_wait(env, ext, OES_TRUNC); rc = osc_extent_truncate(ext, index, partial); if (rc < 0) { if (result == 0) result = rc; OSC_EXTENT_DUMP(D_ERROR, ext, "truncate error %d\n", rc); } else if (ext->oe_nr_pages == 0) { osc_extent_remove(ext); } else { /* this must be an overlapped extent which means only * part of pages in this extent have been truncated. */ EASSERTF(ext->oe_start <= index, ext, "trunc index = %lu/%d.\n", index, partial); /* fix index to skip this partially truncated extent */ index = ext->oe_end + 1; partial = false; /* we need to hold this extent in OES_TRUNC state so * that no writeback will happen. This is to avoid * BUG 17397. */ LASSERT(oio->oi_trunc == NULL); oio->oi_trunc = osc_extent_get(ext); OSC_EXTENT_DUMP(D_CACHE, ext, "trunc at "LPU64"\n", size); } osc_extent_put(env, ext); } if (waiting != NULL) { int rc; /* ignore the result of osc_extent_wait the write initiator * should take care of it. */ rc = osc_extent_wait(env, waiting, OES_INV); if (rc < 0) OSC_EXTENT_DUMP(D_CACHE, waiting, "error: %d.\n", rc); osc_extent_put(env, waiting); waiting = NULL; goto again; } RETURN(result); } /** * Called after osc_io_setattr_end to add oio->oi_trunc back to cache. */ void osc_cache_truncate_end(const struct lu_env *env, struct osc_io *oio, struct osc_object *obj) { struct osc_extent *ext = oio->oi_trunc; oio->oi_trunc = NULL; if (ext != NULL) { bool unplug = false; EASSERT(ext->oe_nr_pages > 0, ext); EASSERT(ext->oe_state == OES_TRUNC, ext); EASSERT(!ext->oe_urgent, ext); OSC_EXTENT_DUMP(D_CACHE, ext, "trunc -> cache.\n"); osc_object_lock(obj); osc_extent_state_set(ext, OES_CACHE); if (ext->oe_fsync_wait && !ext->oe_urgent) { ext->oe_urgent = 1; list_move_tail(&ext->oe_link, &obj->oo_urgent_exts); unplug = true; } osc_update_pending(obj, OBD_BRW_WRITE, ext->oe_nr_pages); osc_object_unlock(obj); osc_extent_put(env, ext); if (unplug) osc_io_unplug_async(env, osc_cli(obj), obj); } } /** * Wait for extents in a specific range to be written out. * The caller must have called osc_cache_writeback_range() to issue IO * otherwise it will take a long time for this function to finish. * * Caller must hold inode_mutex , or cancel exclusive dlm lock so that * nobody else can dirty this range of file while we're waiting for * extents to be written. */ int osc_cache_wait_range(const struct lu_env *env, struct osc_object *obj, pgoff_t start, pgoff_t end) { struct osc_extent *ext; pgoff_t index = start; int result = 0; ENTRY; again: osc_object_lock(obj); ext = osc_extent_search(obj, index); if (ext == NULL) ext = first_extent(obj); else if (ext->oe_end < index) ext = next_extent(ext); while (ext != NULL) { int rc; if (ext->oe_start > end) break; if (!ext->oe_fsync_wait) { ext = next_extent(ext); continue; } EASSERT(ergo(ext->oe_state == OES_CACHE, ext->oe_hp || ext->oe_urgent), ext); EASSERT(ergo(ext->oe_state == OES_ACTIVE, !ext->oe_hp && ext->oe_urgent), ext); index = ext->oe_end + 1; osc_extent_get(ext); osc_object_unlock(obj); rc = osc_extent_wait(env, ext, OES_INV); if (result == 0) result = rc; osc_extent_put(env, ext); goto again; } osc_object_unlock(obj); OSC_IO_DEBUG(obj, "sync file range.\n"); RETURN(result); } /** * Called to write out a range of osc object. * * @hp : should be set this is caused by lock cancel; * @discard: is set if dirty pages should be dropped - file will be deleted or * truncated, this implies there is no partially discarding extents. * * Return how many pages will be issued, or error code if error occurred. */ int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj, pgoff_t start, pgoff_t end, int hp, int discard) { struct osc_extent *ext; struct list_head discard_list = LIST_HEAD_INIT(discard_list); bool unplug = false; int result = 0; ENTRY; osc_object_lock(obj); ext = osc_extent_search(obj, start); if (ext == NULL) ext = first_extent(obj); else if (ext->oe_end < start) ext = next_extent(ext); while (ext != NULL) { if (ext->oe_start > end) break; ext->oe_fsync_wait = 1; switch (ext->oe_state) { case OES_CACHE: result += ext->oe_nr_pages; if (!discard) { struct list_head *list = NULL; if (hp) { EASSERT(!ext->oe_hp, ext); ext->oe_hp = 1; list = &obj->oo_hp_exts; } else if (!ext->oe_urgent) { ext->oe_urgent = 1; list = &obj->oo_urgent_exts; } if (list != NULL) list_move_tail(&ext->oe_link, list); unplug = true; } else { /* the only discarder is lock cancelling, so * [start, end] must contain this extent */ EASSERT(ext->oe_start >= start && ext->oe_max_end <= end, ext); osc_extent_state_set(ext, OES_LOCKING); ext->oe_owner = current; list_move_tail(&ext->oe_link, &discard_list); osc_update_pending(obj, OBD_BRW_WRITE, -ext->oe_nr_pages); } break; case OES_ACTIVE: /* It's pretty bad to wait for ACTIVE extents, because * we don't know how long we will wait for it to be * flushed since it may be blocked at awaiting more * grants. We do this for the correctness of fsync. */ LASSERT(hp == 0 && discard == 0); ext->oe_urgent = 1; break; case OES_TRUNC: /* this extent is being truncated, can't do anything * for it now. it will be set to urgent after truncate * is finished in osc_cache_truncate_end(). */ default: break; } ext = next_extent(ext); } osc_object_unlock(obj); LASSERT(ergo(!discard, list_empty(&discard_list))); if (!list_empty(&discard_list)) { struct osc_extent *tmp; int rc; osc_list_maint(osc_cli(obj), obj); list_for_each_entry_safe(ext, tmp, &discard_list, oe_link) { list_del_init(&ext->oe_link); EASSERT(ext->oe_state == OES_LOCKING, ext); /* Discard caching pages. We don't actually write this * extent out but we complete it as if we did. */ rc = osc_extent_make_ready(env, ext); if (unlikely(rc < 0)) { OSC_EXTENT_DUMP(D_ERROR, ext, "make_ready returned %d\n", rc); if (result >= 0) result = rc; } /* finish the extent as if the pages were sent */ osc_extent_finish(env, ext, 0, 0); } } if (unplug) osc_io_unplug(env, osc_cli(obj), obj, PDL_POLICY_ROUND); if (hp || discard) { int rc; rc = osc_cache_wait_range(env, obj, start, end); if (result >= 0 && rc < 0) result = rc; } OSC_IO_DEBUG(obj, "pageout [%lu, %lu], %d.\n", start, end, result); RETURN(result); } /** * Returns a list of pages by a given [start, end] of \a obj. * * \param resched If not NULL, then we give up before hogging CPU for too * long and set *resched = 1, in that case caller should implement a retry * logic. * * Gang tree lookup (radix_tree_gang_lookup()) optimization is absolutely * crucial in the face of [offset, EOF] locks. * * Return at least one page in @queue unless there is no covered page. */ int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io, struct osc_object *osc, pgoff_t start, pgoff_t end, osc_page_gang_cbt cb, void *cbdata) { struct osc_page *ops; void **pvec; pgoff_t idx; unsigned int nr; unsigned int i; unsigned int j; int res = CLP_GANG_OKAY; bool tree_lock = true; ENTRY; idx = start; pvec = osc_env_info(env)->oti_pvec; spin_lock(&osc->oo_tree_lock); while ((nr = radix_tree_gang_lookup(&osc->oo_tree, pvec, idx, OTI_PVEC_SIZE)) > 0) { struct cl_page *page; bool end_of_region = false; for (i = 0, j = 0; i < nr; ++i) { ops = pvec[i]; pvec[i] = NULL; idx = osc_index(ops); if (idx > end) { end_of_region = true; break; } page = ops->ops_cl.cpl_page; LASSERT(page->cp_type == CPT_CACHEABLE); if (page->cp_state == CPS_FREEING) continue; cl_page_get(page); lu_ref_add_atomic(&page->cp_reference, "gang_lookup", current); pvec[j++] = ops; } ++idx; /* * Here a delicate locking dance is performed. Current thread * holds a reference to a page, but has to own it before it * can be placed into queue. Owning implies waiting, so * radix-tree lock is to be released. After a wait one has to * check that pages weren't truncated (cl_page_own() returns * error in the latter case). */ spin_unlock(&osc->oo_tree_lock); tree_lock = false; for (i = 0; i < j; ++i) { ops = pvec[i]; if (res == CLP_GANG_OKAY) res = (*cb)(env, io, ops, cbdata); page = ops->ops_cl.cpl_page; lu_ref_del(&page->cp_reference, "gang_lookup", current); cl_page_put(env, page); } if (nr < OTI_PVEC_SIZE || end_of_region) break; if (res == CLP_GANG_OKAY && need_resched()) res = CLP_GANG_RESCHED; if (res != CLP_GANG_OKAY) break; spin_lock(&osc->oo_tree_lock); tree_lock = true; } if (tree_lock) spin_unlock(&osc->oo_tree_lock); RETURN(res); } /** * Check if page @page is covered by an extra lock or discard it. */ static int check_and_discard_cb(const struct lu_env *env, struct cl_io *io, struct osc_page *ops, void *cbdata) { struct osc_thread_info *info = osc_env_info(env); struct cl_lock *lock = cbdata; pgoff_t index; index = osc_index(ops); if (index >= info->oti_fn_index) { struct cl_lock *tmp; struct cl_page *page = ops->ops_cl.cpl_page; /* refresh non-overlapped index */ tmp = cl_lock_at_pgoff(env, lock->cll_descr.cld_obj, index, lock, 1, 0); if (tmp != NULL) { /* Cache the first-non-overlapped index so as to skip * all pages within [index, oti_fn_index). This * is safe because if tmp lock is canceled, it will * discard these pages. */ info->oti_fn_index = tmp->cll_descr.cld_end + 1; if (tmp->cll_descr.cld_end == CL_PAGE_EOF) info->oti_fn_index = CL_PAGE_EOF; cl_lock_put(env, tmp); } else if (cl_page_own(env, io, page) == 0) { /* discard the page */ cl_page_discard(env, io, page); cl_page_disown(env, io, page); } else { LASSERT(page->cp_state == CPS_FREEING); } } info->oti_next_index = index + 1; return CLP_GANG_OKAY; } static int discard_cb(const struct lu_env *env, struct cl_io *io, struct osc_page *ops, void *cbdata) { struct osc_thread_info *info = osc_env_info(env); struct cl_lock *lock = cbdata; struct cl_page *page = ops->ops_cl.cpl_page; LASSERT(lock->cll_descr.cld_mode >= CLM_WRITE); /* page is top page. */ info->oti_next_index = osc_index(ops) + 1; if (cl_page_own(env, io, page) == 0) { KLASSERT(ergo(page->cp_type == CPT_CACHEABLE, !PageDirty(cl_page_vmpage(page)))); /* discard the page */ cl_page_discard(env, io, page); cl_page_disown(env, io, page); } else { LASSERT(page->cp_state == CPS_FREEING); } return CLP_GANG_OKAY; } /** * Discard pages protected by the given lock. This function traverses radix * tree to find all covering pages and discard them. If a page is being covered * by other locks, it should remain in cache. * * If error happens on any step, the process continues anyway (the reasoning * behind this being that lock cancellation cannot be delayed indefinitely). */ int osc_lock_discard_pages(const struct lu_env *env, struct osc_lock *ols) { struct osc_thread_info *info = osc_env_info(env); struct cl_io *io = &info->oti_io; struct cl_object *osc = ols->ols_cl.cls_obj; struct cl_lock *lock = ols->ols_cl.cls_lock; struct cl_lock_descr *descr = &lock->cll_descr; osc_page_gang_cbt cb; int res; int result; ENTRY; io->ci_obj = cl_object_top(osc); io->ci_ignore_layout = 1; result = cl_io_init(env, io, CIT_MISC, io->ci_obj); if (result != 0) GOTO(out, result); cb = descr->cld_mode == CLM_READ ? check_and_discard_cb : discard_cb; info->oti_fn_index = info->oti_next_index = descr->cld_start; do { res = osc_page_gang_lookup(env, io, cl2osc(osc), info->oti_next_index, descr->cld_end, cb, (void *)lock); if (info->oti_next_index > descr->cld_end) break; if (res == CLP_GANG_RESCHED) cond_resched(); } while (res != CLP_GANG_OKAY); out: cl_io_fini(env, io); RETURN(result); } /** @} osc */