diff options
Diffstat (limited to 'fs/fscache')
-rw-r--r-- | fs/fscache/cookie.c | 193 | ||||
-rw-r--r-- | fs/fscache/fsdef.c | 1 | ||||
-rw-r--r-- | fs/fscache/netfs.c | 1 | ||||
-rw-r--r-- | fs/fscache/object.c | 7 | ||||
-rw-r--r-- | fs/fscache/page.c | 59 |
5 files changed, 191 insertions, 70 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c index b2a86e3..29d7feb 100644 --- a/fs/fscache/cookie.c +++ b/fs/fscache/cookie.c @@ -58,15 +58,16 @@ void fscache_cookie_init_once(void *_cookie) struct fscache_cookie *__fscache_acquire_cookie( struct fscache_cookie *parent, const struct fscache_cookie_def *def, - void *netfs_data) + void *netfs_data, + bool enable) { struct fscache_cookie *cookie; BUG_ON(!def); - _enter("{%s},{%s},%p", + _enter("{%s},{%s},%p,%u", parent ? (char *) parent->def->name : "<no-parent>", - def->name, netfs_data); + def->name, netfs_data, enable); fscache_stat(&fscache_n_acquires); @@ -106,7 +107,7 @@ struct fscache_cookie *__fscache_acquire_cookie( cookie->def = def; cookie->parent = parent; cookie->netfs_data = netfs_data; - cookie->flags = 0; + cookie->flags = (1 << FSCACHE_COOKIE_NO_DATA_YET); /* radix tree insertion won't use the preallocation pool unless it's * told it may not wait */ @@ -124,16 +125,22 @@ struct fscache_cookie *__fscache_acquire_cookie( break; } - /* if the object is an index then we need do nothing more here - we - * create indices on disk when we need them as an index may exist in - * multiple caches */ - if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) { - if (fscache_acquire_non_index_cookie(cookie) < 0) { - atomic_dec(&parent->n_children); - __fscache_cookie_put(cookie); - fscache_stat(&fscache_n_acquires_nobufs); - _leave(" = NULL"); - return NULL; + if (enable) { + /* if the object is an index then we need do nothing more here + * - we create indices on disk when we need them as an index + * may exist in multiple caches */ + if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) { + if (fscache_acquire_non_index_cookie(cookie) == 0) { + set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); + } else { + atomic_dec(&parent->n_children); + __fscache_cookie_put(cookie); + fscache_stat(&fscache_n_acquires_nobufs); + _leave(" = NULL"); + return NULL; + } + } else { + set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); } } @@ -144,6 +151,39 @@ struct fscache_cookie *__fscache_acquire_cookie( EXPORT_SYMBOL(__fscache_acquire_cookie); /* + * Enable a cookie to permit it to accept new operations. + */ +void __fscache_enable_cookie(struct fscache_cookie *cookie, + bool (*can_enable)(void *data), + void *data) +{ + _enter("%p", cookie); + + wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK, + fscache_wait_bit, TASK_UNINTERRUPTIBLE); + + if (test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags)) + goto out_unlock; + + if (can_enable && !can_enable(data)) { + /* The netfs decided it didn't want to enable after all */ + } else if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX) { + /* Wait for outstanding disablement to complete */ + __fscache_wait_on_invalidate(cookie); + + if (fscache_acquire_non_index_cookie(cookie) == 0) + set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); + } else { + set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); + } + +out_unlock: + clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags); + wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK); +} +EXPORT_SYMBOL(__fscache_enable_cookie); + +/* * acquire a non-index cookie * - this must make sure the index chain is instantiated and instantiate the * object representation too @@ -157,7 +197,7 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie) _enter(""); - cookie->flags = 1 << FSCACHE_COOKIE_UNAVAILABLE; + set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); /* now we need to see whether the backing objects for this cookie yet * exist, if not there'll be nothing to search */ @@ -180,9 +220,7 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie) _debug("cache %s", cache->tag->name); - cookie->flags = - (1 << FSCACHE_COOKIE_LOOKING_UP) | - (1 << FSCACHE_COOKIE_NO_DATA_YET); + set_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags); /* ask the cache to allocate objects for this cookie and its parent * chain */ @@ -398,7 +436,8 @@ void __fscache_invalidate(struct fscache_cookie *cookie) if (!hlist_empty(&cookie->backing_objects)) { spin_lock(&cookie->lock); - if (!hlist_empty(&cookie->backing_objects) && + if (fscache_cookie_enabled(cookie) && + !hlist_empty(&cookie->backing_objects) && !test_and_set_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) { object = hlist_entry(cookie->backing_objects.first, @@ -452,10 +491,14 @@ void __fscache_update_cookie(struct fscache_cookie *cookie) spin_lock(&cookie->lock); - /* update the index entry on disk in each cache backing this cookie */ - hlist_for_each_entry(object, - &cookie->backing_objects, cookie_link) { - fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE); + if (fscache_cookie_enabled(cookie)) { + /* update the index entry on disk in each cache backing this + * cookie. + */ + hlist_for_each_entry(object, + &cookie->backing_objects, cookie_link) { + fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE); + } } spin_unlock(&cookie->lock); @@ -464,28 +507,14 @@ void __fscache_update_cookie(struct fscache_cookie *cookie) EXPORT_SYMBOL(__fscache_update_cookie); /* - * release a cookie back to the cache - * - the object will be marked as recyclable on disk if retire is true - * - all dependents of this cookie must have already been unregistered - * (indices/files/pages) + * Disable a cookie to stop it from accepting new requests from the netfs. */ -void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire) +void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate) { struct fscache_object *object; + bool awaken = false; - fscache_stat(&fscache_n_relinquishes); - if (retire) - fscache_stat(&fscache_n_relinquishes_retire); - - if (!cookie) { - fscache_stat(&fscache_n_relinquishes_null); - _leave(" [no cookie]"); - return; - } - - _enter("%p{%s,%p,%d},%d", - cookie, cookie->def->name, cookie->netfs_data, - atomic_read(&cookie->n_active), retire); + _enter("%p,%u", cookie, invalidate); ASSERTCMP(atomic_read(&cookie->n_active), >, 0); @@ -495,24 +524,82 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire) BUG(); } - /* No further netfs-accessing operations on this cookie permitted */ - set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags); - if (retire) - set_bit(FSCACHE_COOKIE_RETIRED, &cookie->flags); + wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK, + fscache_wait_bit, TASK_UNINTERRUPTIBLE); + if (!test_and_clear_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags)) + goto out_unlock_enable; + + /* If the cookie is being invalidated, wait for that to complete first + * so that we can reuse the flag. + */ + __fscache_wait_on_invalidate(cookie); + + /* Dispose of the backing objects */ + set_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags); spin_lock(&cookie->lock); - hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) { - fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL); + if (!hlist_empty(&cookie->backing_objects)) { + hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) { + if (invalidate) + set_bit(FSCACHE_OBJECT_RETIRED, &object->flags); + fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL); + } + } else { + if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) + awaken = true; } spin_unlock(&cookie->lock); + if (awaken) + wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING); /* Wait for cessation of activity requiring access to the netfs (when - * n_active reaches 0). + * n_active reaches 0). This makes sure outstanding reads and writes + * have completed. */ if (!atomic_dec_and_test(&cookie->n_active)) wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t, TASK_UNINTERRUPTIBLE); + /* Reset the cookie state if it wasn't relinquished */ + if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) { + atomic_inc(&cookie->n_active); + set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); + } + +out_unlock_enable: + clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags); + wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK); + _leave(""); +} +EXPORT_SYMBOL(__fscache_disable_cookie); + +/* + * release a cookie back to the cache + * - the object will be marked as recyclable on disk if retire is true + * - all dependents of this cookie must have already been unregistered + * (indices/files/pages) + */ +void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire) +{ + fscache_stat(&fscache_n_relinquishes); + if (retire) + fscache_stat(&fscache_n_relinquishes_retire); + + if (!cookie) { + fscache_stat(&fscache_n_relinquishes_null); + _leave(" [no cookie]"); + return; + } + + _enter("%p{%s,%p,%d},%d", + cookie, cookie->def->name, cookie->netfs_data, + atomic_read(&cookie->n_active), retire); + + /* No further netfs-accessing operations on this cookie permitted */ + set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags); + + __fscache_disable_cookie(cookie, retire); + /* Clear pointers back to the netfs */ cookie->netfs_data = NULL; cookie->def = NULL; @@ -568,6 +655,7 @@ int __fscache_check_consistency(struct fscache_cookie *cookie) { struct fscache_operation *op; struct fscache_object *object; + bool wake_cookie = false; int ret; _enter("%p,", cookie); @@ -591,7 +679,8 @@ int __fscache_check_consistency(struct fscache_cookie *cookie) spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto inconsistent; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); @@ -600,7 +689,7 @@ int __fscache_check_consistency(struct fscache_cookie *cookie) op->debug_id = atomic_inc_return(&fscache_op_debug_id); - atomic_inc(&cookie->n_active); + __fscache_use_cookie(cookie); if (fscache_submit_op(object, op) < 0) goto submit_failed; @@ -622,9 +711,11 @@ int __fscache_check_consistency(struct fscache_cookie *cookie) return ret; submit_failed: - atomic_dec(&cookie->n_active); + wake_cookie = __fscache_unuse_cookie(cookie); inconsistent: spin_unlock(&cookie->lock); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); kfree(op); _leave(" = -ESTALE"); return -ESTALE; diff --git a/fs/fscache/fsdef.c b/fs/fscache/fsdef.c index 10a2ade..5a117df 100644 --- a/fs/fscache/fsdef.c +++ b/fs/fscache/fsdef.c @@ -59,6 +59,7 @@ struct fscache_cookie fscache_fsdef_index = { .lock = __SPIN_LOCK_UNLOCKED(fscache_fsdef_index.lock), .backing_objects = HLIST_HEAD_INIT, .def = &fscache_fsdef_index_def, + .flags = 1 << FSCACHE_COOKIE_ENABLED, }; EXPORT_SYMBOL(fscache_fsdef_index); diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c index b1bb611..989f394 100644 --- a/fs/fscache/netfs.c +++ b/fs/fscache/netfs.c @@ -45,6 +45,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs) netfs->primary_index->def = &fscache_fsdef_netfs_def; netfs->primary_index->parent = &fscache_fsdef_index; netfs->primary_index->netfs_data = netfs; + netfs->primary_index->flags = 1 << FSCACHE_COOKIE_ENABLED; atomic_inc(&netfs->primary_index->parent->usage); atomic_inc(&netfs->primary_index->parent->n_children); diff --git a/fs/fscache/object.c b/fs/fscache/object.c index 3b07122..53d35c5 100644 --- a/fs/fscache/object.c +++ b/fs/fscache/object.c @@ -495,6 +495,7 @@ void fscache_object_lookup_negative(struct fscache_object *object) * returning ENODATA. */ set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); + clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); _debug("wake up lookup %p", &cookie->flags); clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags); @@ -527,6 +528,7 @@ void fscache_obtained_object(struct fscache_object *object) /* We do (presumably) have data */ clear_bit_unlock(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); + clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); /* Allow write requests to begin stacking up and read requests * to begin shovelling data. @@ -679,7 +681,8 @@ static const struct fscache_state *fscache_drop_object(struct fscache_object *ob */ spin_lock(&cookie->lock); hlist_del_init(&object->cookie_link); - if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) + if (hlist_empty(&cookie->backing_objects) && + test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) awaken = true; spin_unlock(&cookie->lock); @@ -927,7 +930,7 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj */ if (!fscache_use_cookie(object)) { ASSERT(object->cookie->stores.rnode == NULL); - set_bit(FSCACHE_COOKIE_RETIRED, &cookie->flags); + set_bit(FSCACHE_OBJECT_RETIRED, &object->flags); _leave(" [no cookie]"); return transit_to(KILL_OBJECT); } diff --git a/fs/fscache/page.c b/fs/fscache/page.c index 73899c1..7f5c658 100644 --- a/fs/fscache/page.c +++ b/fs/fscache/page.c @@ -163,12 +163,10 @@ static void fscache_attr_changed_op(struct fscache_operation *op) fscache_stat(&fscache_n_attr_changed_calls); - if (fscache_object_is_active(object) && - fscache_use_cookie(object)) { + if (fscache_object_is_active(object)) { fscache_stat(&fscache_n_cop_attr_changed); ret = object->cache->ops->attr_changed(object); fscache_stat_d(&fscache_n_cop_attr_changed); - fscache_unuse_cookie(object); if (ret < 0) fscache_abort_object(object); } @@ -184,6 +182,7 @@ int __fscache_attr_changed(struct fscache_cookie *cookie) { struct fscache_operation *op; struct fscache_object *object; + bool wake_cookie; _enter("%p", cookie); @@ -199,15 +198,19 @@ int __fscache_attr_changed(struct fscache_cookie *cookie) } fscache_operation_init(op, fscache_attr_changed_op, NULL); - op->flags = FSCACHE_OP_ASYNC | (1 << FSCACHE_OP_EXCLUSIVE); + op->flags = FSCACHE_OP_ASYNC | + (1 << FSCACHE_OP_EXCLUSIVE) | + (1 << FSCACHE_OP_UNUSE_COOKIE); spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto nobufs; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); + __fscache_use_cookie(cookie); if (fscache_submit_exclusive_op(object, op) < 0) goto nobufs; spin_unlock(&cookie->lock); @@ -217,8 +220,11 @@ int __fscache_attr_changed(struct fscache_cookie *cookie) return 0; nobufs: + wake_cookie = __fscache_unuse_cookie(cookie); spin_unlock(&cookie->lock); kfree(op); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); fscache_stat(&fscache_n_attr_changed_nobufs); _leave(" = %d", -ENOBUFS); return -ENOBUFS; @@ -263,7 +269,6 @@ static struct fscache_retrieval *fscache_alloc_retrieval( } fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op); - atomic_inc(&cookie->n_active); op->op.flags = FSCACHE_OP_MYTHREAD | (1UL << FSCACHE_OP_WAITING) | (1UL << FSCACHE_OP_UNUSE_COOKIE); @@ -384,6 +389,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, { struct fscache_retrieval *op; struct fscache_object *object; + bool wake_cookie = false; int ret; _enter("%p,%p,,,", cookie, page); @@ -405,7 +411,7 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, return -ERESTARTSYS; op = fscache_alloc_retrieval(cookie, page->mapping, - end_io_func,context); + end_io_func, context); if (!op) { _leave(" = -ENOMEM"); return -ENOMEM; @@ -414,13 +420,15 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie, spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto nobufs_unlock; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)); + __fscache_use_cookie(cookie); atomic_inc(&object->n_reads); __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); @@ -475,9 +483,11 @@ error: nobufs_unlock_dec: atomic_dec(&object->n_reads); + wake_cookie = __fscache_unuse_cookie(cookie); nobufs_unlock: spin_unlock(&cookie->lock); - atomic_dec(&cookie->n_active); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); kfree(op); nobufs: fscache_stat(&fscache_n_retrievals_nobufs); @@ -514,6 +524,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, { struct fscache_retrieval *op; struct fscache_object *object; + bool wake_cookie = false; int ret; _enter("%p,,%d,,,", cookie, *nr_pages); @@ -542,11 +553,13 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie, spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto nobufs_unlock; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); + __fscache_use_cookie(cookie); atomic_inc(&object->n_reads); __set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags); @@ -601,10 +614,12 @@ error: nobufs_unlock_dec: atomic_dec(&object->n_reads); + wake_cookie = __fscache_unuse_cookie(cookie); nobufs_unlock: spin_unlock(&cookie->lock); - atomic_dec(&cookie->n_active); kfree(op); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); nobufs: fscache_stat(&fscache_n_retrievals_nobufs); _leave(" = -ENOBUFS"); @@ -626,6 +641,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie, { struct fscache_retrieval *op; struct fscache_object *object; + bool wake_cookie = false; int ret; _enter("%p,%p,,,", cookie, page); @@ -653,13 +669,15 @@ int __fscache_alloc_page(struct fscache_cookie *cookie, spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto nobufs_unlock; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); + __fscache_use_cookie(cookie); if (fscache_submit_op(object, &op->op) < 0) - goto nobufs_unlock; + goto nobufs_unlock_dec; spin_unlock(&cookie->lock); fscache_stat(&fscache_n_alloc_ops); @@ -689,10 +707,13 @@ error: _leave(" = %d", ret); return ret; +nobufs_unlock_dec: + wake_cookie = __fscache_unuse_cookie(cookie); nobufs_unlock: spin_unlock(&cookie->lock); - atomic_dec(&cookie->n_active); kfree(op); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); nobufs: fscache_stat(&fscache_n_allocs_nobufs); _leave(" = -ENOBUFS"); @@ -889,6 +910,7 @@ int __fscache_write_page(struct fscache_cookie *cookie, { struct fscache_storage *op; struct fscache_object *object; + bool wake_cookie = false; int ret; _enter("%p,%x,", cookie, (u32) page->flags); @@ -920,7 +942,8 @@ int __fscache_write_page(struct fscache_cookie *cookie, ret = -ENOBUFS; spin_lock(&cookie->lock); - if (hlist_empty(&cookie->backing_objects)) + if (!fscache_cookie_enabled(cookie) || + hlist_empty(&cookie->backing_objects)) goto nobufs; object = hlist_entry(cookie->backing_objects.first, struct fscache_object, cookie_link); @@ -957,7 +980,7 @@ int __fscache_write_page(struct fscache_cookie *cookie, op->op.debug_id = atomic_inc_return(&fscache_op_debug_id); op->store_limit = object->store_limit; - atomic_inc(&cookie->n_active); + __fscache_use_cookie(cookie); if (fscache_submit_op(object, &op->op) < 0) goto submit_failed; @@ -984,10 +1007,10 @@ already_pending: return 0; submit_failed: - atomic_dec(&cookie->n_active); spin_lock(&cookie->stores_lock); radix_tree_delete(&cookie->stores, page->index); spin_unlock(&cookie->stores_lock); + wake_cookie = __fscache_unuse_cookie(cookie); page_cache_release(page); ret = -ENOBUFS; goto nobufs; @@ -999,6 +1022,8 @@ nobufs: spin_unlock(&cookie->lock); radix_tree_preload_end(); kfree(op); + if (wake_cookie) + __fscache_wake_unused_cookie(cookie); fscache_stat(&fscache_n_stores_nobufs); _leave(" = -ENOBUFS"); return -ENOBUFS; |