diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/osc/osc_cache.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/osc/osc_cache.c | 2916 |
1 files changed, 2916 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c new file mode 100644 index 000000000000..0a0ec6f7d2dd --- /dev/null +++ b/drivers/staging/lustre/lustre/osc/osc_cache.c @@ -0,0 +1,2916 @@ +/* + * 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, 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 <jinshan.xiong@whamcloud.com> + */ + +#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 = oap2cl_page(oap)->cp_index; + ++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, 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, 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, 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, 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); + 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 = oap->oap_page_off & ~CFS_PAGE_MASK; + int count = oap->oap_count + (offset & (blocksize - 1)); + int end = (offset + oap->oap_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(LWI_ON_SIGNAL_NOOP, 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) { + struct cl_page *sub = oap2cl_page(oap); + struct cl_page *page = cl_page_top(sub); + + LASSERT(list_empty(&oap->oap_rpc_item)); + + /* only discard the pages with their index greater than + * trunc_index, and ... */ + if (sub->cp_index < trunc_index || + (sub->cp_index == trunc_index && partial)) { + /* accounting how many pages remaining in the chunk + * so that we can calculate grants correctly. */ + if (sub->cp_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_unmap(env, io, page); + 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); + last->oap_async_flags |= ASYNC_COUNT_STABLE; + } + + /* 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; + oap->oap_async_flags |= ASYNC_COUNT_STABLE; + } + } + + 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 = cl_page_top(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); + struct cl_page *page = oap2cl_page(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, page->cp_index) >= kms) + /* catch race with truncate */ + return 0; + else if (cl_offset(obj, page->cp_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 = cl_page_top(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; + LASSERT(equi(page->cp_state == CPS_PAGEIN, cmd == OBD_BRW_READ)); + LASSERT(equi(page->cp_state == CPS_PAGEOUT, cmd == OBD_BRW_WRITE)); + 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(cli, fmt, args...) do { \ + struct client_obd *__tmp = (cli); \ + CDEBUG(D_CACHE, "%s: { dirty: %ld/%ld dirty_pages: %d/%d " \ + "dropped: %ld avail: %ld, reserved: %ld, flight: %d } " fmt, \ + __tmp->cl_import->imp_obd->obd_name, \ + __tmp->cl_dirty, __tmp->cl_dirty_max, \ + atomic_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, ##args); \ +} while (0) + +/* caller must hold loi_list_lock */ +static void osc_consume_write_grant(struct client_obd *cli, + struct brw_page *pga) +{ + LASSERT(spin_is_locked(&cli->cl_loi_list_lock.lock)); + LASSERT(!(pga->flag & OBD_BRW_FROM_GRANT)); + atomic_inc(&obd_dirty_pages); + cli->cl_dirty += PAGE_CACHE_SIZE; + 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; + + LASSERT(spin_is_locked(&cli->cl_loi_list_lock.lock)); + if (!(pga->flag & OBD_BRW_FROM_GRANT)) { + EXIT; + return; + } + + pga->flag &= ~OBD_BRW_FROM_GRANT; + atomic_dec(&obd_dirty_pages); + cli->cl_dirty -= PAGE_CACHE_SIZE; + if (pga->flag & OBD_BRW_NOCACHE) { + pga->flag &= ~OBD_BRW_NOCACHE; + atomic_dec(&obd_dirty_transit_pages); + cli->cl_dirty_transit -= PAGE_CACHE_SIZE; + } + 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_sub(nr_pages, &obd_dirty_pages); + cli->cl_dirty -= nr_pages << PAGE_CACHE_SHIFT; + 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); +} + +/** + * 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(cli, "need:%d.\n", bytes); + + rc = osc_reserve_grant(cli, bytes); + if (rc < 0) + return 0; + + if (cli->cl_dirty + PAGE_CACHE_SIZE <= cli->cl_dirty_max && + atomic_read(&obd_dirty_pages) + 1 <= obd_max_dirty_pages) { + osc_consume_write_grant(cli, &oap->oap_brw_page); + if (transient) { + cli->cl_dirty_transit += PAGE_CACHE_SIZE; + atomic_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_INTR(LWI_ON_SIGNAL_NOOP, NULL); + int rc = -EDQUOT; + ENTRY; + + OSC_DUMP_GRANT(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 < PAGE_CACHE_SIZE || + 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 > 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 */ + if (rc < 0) { + 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(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 + PAGE_CACHE_SIZE > cli->cl_dirty_max) || + (atomic_read(&obd_dirty_pages) + 1 > + obd_max_dirty_pages)) { + CDEBUG(D_CACHE, "no dirty room: dirty: %ld " + "osc max %ld, sys max %d\n", cli->cl_dirty, + cli->cl_dirty_max, 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; + 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) { + 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 (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) +{ + LIST_HEAD(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) +{ + struct osc_extent *ext; + struct osc_extent *next; + LIST_HEAD(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) +{ + 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); + link = lu_object_ref_add(&obj->co_lu, "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; + 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 = oap2cl_page(oap)->cp_index; + + /* 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, oap2cl_page(oap)->cp_index); + + 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, oap2cl_page(oap)->cp_index); + /* 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", + oap2cl_page(oap)->cp_index); + 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 = cp->cp_index; + 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, cl_page_top(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 */ + GOTO(out, rc = -EAGAIN); + default: + break; + } + + rc = cl_page_prep(env, io, cl_page_top(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 = oap2cl_page(oap)->cp_index; + 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, *tmp; + 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) { + struct cl_page *cp = oap2cl_page(oap); + if (cp->cp_index > end) + end = cp->cp_index; + if (cp->cp_index < start) + start = cp->cp_index; + ++page_count; + mppr <<= (page_count > mppr); + } + + ext = osc_extent_alloc(obj); + if (ext == NULL) { + list_for_each_entry_safe(oap, tmp, 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(env, cli, obj, PDL_POLICY_ROUND); + 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; + LIST_HEAD(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; + LIST_HEAD(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, "cache page out.\n"); + RETURN(result); +} + +/** @} osc */ |