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);
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 */
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);
}
}
}
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
_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 */
_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 */
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,
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);
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);
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;
{
struct fscache_operation *op;
struct fscache_object *object;
+ bool wake_cookie = false;
int ret;
_enter("%p,", 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);
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;
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;
projects / ~andy / linux / blobdiff