--- /dev/null
+/*
+ * 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)) {
+ rc = 9;
+ goto out;
+ }
+
+ if (ext->oe_state >= OES_STATE_MAX) {
+ rc = 10;
+ goto out;
+ }
+
+ if (atomic_read(&ext->oe_refc) <= 0) {
+ rc = 20;
+ goto out;
+ }
+
+ if (atomic_read(&ext->oe_refc) < atomic_read(&ext->oe_users)) {
+ rc = 30;
+ goto out;
+ }
+
+ switch (ext->oe_state) {
+ case OES_INV:
+ if (ext->oe_nr_pages > 0 || !list_empty(&ext->oe_pages))
+ rc = 35;
+ else
+ rc = 0;
+ goto out;
+ case OES_ACTIVE:
+ if (atomic_read(&ext->oe_users) == 0) {
+ rc = 40;
+ goto out;
+ }
+ if (ext->oe_hp) {
+ rc = 50;
+ goto out;
+ }
+ if (ext->oe_fsync_wait && !ext->oe_urgent) {
+ rc = 55;
+ goto out;
+ }
+ break;
+ case OES_CACHE:
+ if (ext->oe_grants == 0) {
+ rc = 60;
+ goto out;
+ }
+ if (ext->oe_fsync_wait && !ext->oe_urgent && !ext->oe_hp) {
+ rc = 65;
+ goto out;
+ }
+ default:
+ if (atomic_read(&ext->oe_users) > 0) {
+ rc = 70;
+ goto out;
+ }
+ }
+
+ if (ext->oe_max_end < ext->oe_end || ext->oe_end < ext->oe_start) {
+ rc = 80;
+ goto out;
+ }
+
+ if (ext->oe_osclock == NULL && ext->oe_grants > 0) {
+ rc = 90;
+ goto out;
+ }
+
+ 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)) {
+ rc = 100;
+ goto out;
+ }
+ }
+
+ if (ext->oe_nr_pages > ext->oe_mppr) {
+ rc = 105;
+ goto out;
+ }
+
+ /* 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) {
+ rc = 0;
+ goto out;
+ }
+
+ if (!extent_debug) {
+ rc = 0;
+ goto out;
+ }
+
+ 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) {
+ rc = 110;
+ goto out;
+ }
+ }
+ if (page_count != ext->oe_nr_pages) {
+ rc = 120;
+ goto out;
+ }
+
+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.
+ */
+void osc_extent_release(const struct lu_env *env, struct osc_extent *ext)
+{
+ struct osc_object *obj = ext->oe_obj;
+
+ 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);
+}
+
+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;
+
+ 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) {
+ found = ERR_PTR(rc);
+ goto out;
+ }
+
+ goto restart;
+ }
+
+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;
+
+ 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;
+
+ 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 &&
+ !ext->oe_trunc_pending) {
+ 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;
+
+ LASSERT(sanity_check(ext) == 0);
+ EASSERT(ext->oe_state == OES_TRUNC, ext);
+ EASSERT(!ext->oe_urgent, ext);
+
+ /* 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;
+
+ /* 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 flushing 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;
+
+ /* 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;
+
+ 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) {
+ rc = -ERANGE;
+ goto out;
+ }
+
+ if (end_chunk >= chunk) {
+ rc = 0;
+ goto out;
+ }
+
+ 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() */
+ rc = -EAGAIN;
+ goto out;
+ }
+
+ 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);
+
+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 */
+
+ 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;
+
+ 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)
+{
+ assert_spin_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)
+{
+ assert_spin_locked(&cli->cl_loi_list_lock.lock);
+ if (!(pga->flag & OBD_BRW_FROM_GRANT)) {
+ 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;
+ }
+}
+
+/**
+ * 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;
+
+ 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) {
+ rc = -EDQUOT;
+ goto out;
+ }
+
+ /* Hopefully normal case - cache space and write credits available */
+ if (osc_enter_cache_try(cli, oap, bytes, 0)) {
+ rc = 0;
+ goto out;
+ }
+
+ /* 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;
+ }
+
+ LASSERT(list_empty(&ocw.ocw_entry));
+ rc = ocw.ocw_rc;
+
+ if (rc != -EDQUOT)
+ goto out;
+ if (osc_enter_cache_try(cli, oap, bytes, 0)) {
+ rc = 0;
+ goto out;
+ }
+ }
+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;
+
+ 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);
+ }
+}
+
+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;
+
+ /* 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 propagate 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;
+
+ 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);
+}
+
+/**
+ * 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);
+
+ 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)
+{
+ LIST_HEAD(rpclist);
+ struct osc_extent *ext;
+ struct osc_extent *tmp;
+ struct osc_extent *first = NULL;
+ u32 page_count = 0;
+ int srvlock = 0;
+ int rc = 0;
+
+ 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;
+
+ 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)
+{
+ /* 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 threshold */
+ 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;
+
+ 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;
+
+ 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) && 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 %llu\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;
+
+ 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)) &&
+ 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 accommodate 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;
+
+ 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;
+
+ 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 */
+ 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. */
+ rc = -EAGAIN;
+ goto out;
+ default:
+ break;
+ }
+
+ rc = cl_page_prep(env, io, cl_page_top(cp), CRT_WRITE);
+ if (rc)
+ goto out;
+
+ 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;
+
+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;
+
+ 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;
+
+ 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_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;
+ LIST_HEAD(list);
+ int result = 0;
+ bool partial;
+
+ /* 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:%llu.\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 %llu\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;
+
+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;
+
+ 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 */
Code Review / kvmfornfv.git / blobdiff