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Diffstat (limited to 'fs/fscache/cookie.c')
-rw-r--r--fs/fscache/cookie.c93
1 files changed, 32 insertions, 61 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index e2cba1f60c21..0e91a3c9fdb2 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -95,6 +95,11 @@ struct fscache_cookie *__fscache_acquire_cookie(
atomic_set(&cookie->usage, 1);
atomic_set(&cookie->n_children, 0);
+ /* We keep the active count elevated until relinquishment to prevent an
+ * attempt to wake up every time the object operations queue quiesces.
+ */
+ atomic_set(&cookie->n_active, 1);
+
atomic_inc(&parent->usage);
atomic_inc(&parent->n_children);
@@ -177,7 +182,6 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie)
cookie->flags =
(1 << FSCACHE_COOKIE_LOOKING_UP) |
- (1 << FSCACHE_COOKIE_CREATING) |
(1 << FSCACHE_COOKIE_NO_DATA_YET);
/* ask the cache to allocate objects for this cookie and its parent
@@ -205,7 +209,7 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie)
/* initiate the process of looking up all the objects in the chain
* (done by fscache_initialise_object()) */
- fscache_enqueue_object(object);
+ fscache_raise_event(object, FSCACHE_OBJECT_EV_NEW_CHILD);
spin_unlock(&cookie->lock);
@@ -285,7 +289,7 @@ static int fscache_alloc_object(struct fscache_cache *cache,
object_already_extant:
ret = -ENOBUFS;
- if (object->state >= FSCACHE_OBJECT_DYING) {
+ if (fscache_object_is_dead(object)) {
spin_unlock(&cookie->lock);
goto error;
}
@@ -321,7 +325,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
ret = -EEXIST;
hlist_for_each_entry(p, &cookie->backing_objects, cookie_link) {
if (p->cache == object->cache) {
- if (p->state >= FSCACHE_OBJECT_DYING)
+ if (fscache_object_is_dying(p))
ret = -ENOBUFS;
goto cant_attach_object;
}
@@ -332,7 +336,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
hlist_for_each_entry(p, &cookie->parent->backing_objects,
cookie_link) {
if (p->cache == object->cache) {
- if (p->state >= FSCACHE_OBJECT_DYING) {
+ if (fscache_object_is_dying(p)) {
ret = -ENOBUFS;
spin_unlock(&cookie->parent->lock);
goto cant_attach_object;
@@ -400,7 +404,7 @@ void __fscache_invalidate(struct fscache_cookie *cookie)
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object,
cookie_link);
- if (object->state < FSCACHE_OBJECT_DYING)
+ if (fscache_object_is_live(object))
fscache_raise_event(
object, FSCACHE_OBJECT_EV_INVALIDATE);
}
@@ -467,9 +471,7 @@ EXPORT_SYMBOL(__fscache_update_cookie);
*/
void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
{
- struct fscache_cache *cache;
struct fscache_object *object;
- unsigned long event;
fscache_stat(&fscache_n_relinquishes);
if (retire)
@@ -481,8 +483,11 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
return;
}
- _enter("%p{%s,%p},%d",
- cookie, cookie->def->name, cookie->netfs_data, retire);
+ _enter("%p{%s,%p,%d},%d",
+ cookie, cookie->def->name, cookie->netfs_data,
+ atomic_read(&cookie->n_active), retire);
+
+ ASSERTCMP(atomic_read(&cookie->n_active), >, 0);
if (atomic_read(&cookie->n_children) != 0) {
printk(KERN_ERR "FS-Cache: Cookie '%s' still has children\n",
@@ -490,62 +495,28 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
BUG();
}
- /* wait for the cookie to finish being instantiated (or to fail) */
- if (test_bit(FSCACHE_COOKIE_CREATING, &cookie->flags)) {
- fscache_stat(&fscache_n_relinquishes_waitcrt);
- wait_on_bit(&cookie->flags, FSCACHE_COOKIE_CREATING,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
- }
-
- event = retire ? FSCACHE_OBJECT_EV_RETIRE : FSCACHE_OBJECT_EV_RELEASE;
+ /* 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);
-try_again:
spin_lock(&cookie->lock);
-
- /* break links with all the active objects */
- while (!hlist_empty(&cookie->backing_objects)) {
- int n_reads;
- object = hlist_entry(cookie->backing_objects.first,
- struct fscache_object,
- cookie_link);
-
- _debug("RELEASE OBJ%x", object->debug_id);
-
- set_bit(FSCACHE_COOKIE_WAITING_ON_READS, &cookie->flags);
- n_reads = atomic_read(&object->n_reads);
- if (n_reads) {
- int n_ops = object->n_ops;
- int n_in_progress = object->n_in_progress;
- spin_unlock(&cookie->lock);
- printk(KERN_ERR "FS-Cache:"
- " Cookie '%s' still has %d outstanding reads (%d,%d)\n",
- cookie->def->name,
- n_reads, n_ops, n_in_progress);
- wait_on_bit(&cookie->flags, FSCACHE_COOKIE_WAITING_ON_READS,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
- printk("Wait finished\n");
- goto try_again;
- }
-
- /* detach each cache object from the object cookie */
- spin_lock(&object->lock);
- hlist_del_init(&object->cookie_link);
-
- cache = object->cache;
- object->cookie = NULL;
- fscache_raise_event(object, event);
- spin_unlock(&object->lock);
-
- if (atomic_dec_and_test(&cookie->usage))
- /* the cookie refcount shouldn't be reduced to 0 yet */
- BUG();
+ hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) {
+ fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
}
+ spin_unlock(&cookie->lock);
- /* detach pointers back to the netfs */
+ /* Wait for cessation of activity requiring access to the netfs (when
+ * n_active reaches 0).
+ */
+ if (!atomic_dec_and_test(&cookie->n_active))
+ wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t,
+ TASK_UNINTERRUPTIBLE);
+
+ /* Clear pointers back to the netfs */
cookie->netfs_data = NULL;
cookie->def = NULL;
-
- spin_unlock(&cookie->lock);
+ BUG_ON(cookie->stores.rnode);
if (cookie->parent) {
ASSERTCMP(atomic_read(&cookie->parent->usage), >, 0);
@@ -553,7 +524,7 @@ try_again:
atomic_dec(&cookie->parent->n_children);
}
- /* finally dispose of the cookie */
+ /* Dispose of the netfs's link to the cookie */
ASSERTCMP(atomic_read(&cookie->usage), >, 0);
fscache_cookie_put(cookie);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 12:31:25 +0100