author: David Howells <dhowells@redhat.com> 2013-05-10 19:50:26 +0100
committer: David Howells <dhowells@redhat.com> 2013-06-19 14:16:47 +0100
commit: 1362729b169b7903c7e739dbe7904994b0d8c47f
parent: caaef6900befb45689b1d1831ce3c7e7fb5b504f
Commit Summary:
Diffstat:
9 files changed, 170 insertions, 214 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index eee436646989..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
@@ -467,7 +471,6 @@ EXPORT_SYMBOL(__fscache_update_cookie);
*/
void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
{
- struct fscache_cache *cache;
struct fscache_object *object;
fscache_stat(&fscache_n_relinquishes);
@@ -480,8 +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",
@@ -489,62 +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);
- }
+ /* 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;
- if (retire)
- set_bit(FSCACHE_OBJECT_RETIRE, &object->flags);
+ hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) {
fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
- spin_unlock(&object->lock);
-
- if (atomic_dec_and_test(&cookie->usage))
- /* the cookie refcount shouldn't be reduced to 0 yet */
- BUG();
}
+ 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);
@@ -552,7 +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);
diff --git a/fs/fscache/fsdef.c b/fs/fscache/fsdef.c
index f5b4baee7352..10a2ade0bdf8 100644
--- a/fs/fscache/fsdef.c
+++ b/fs/fscache/fsdef.c
@@ -55,6 +55,7 @@ static struct fscache_cookie_def fscache_fsdef_index_def = {
struct fscache_cookie fscache_fsdef_index = {
.usage = ATOMIC_INIT(1),
+ .n_active = ATOMIC_INIT(1),
.lock = __SPIN_LOCK_UNLOCKED(fscache_fsdef_index.lock),
.backing_objects = HLIST_HEAD_INIT,
.def = &fscache_fsdef_index_def,
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 3322d3c42ba8..12d505bedb5c 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -93,6 +93,7 @@ static inline bool fscache_object_congested(void)
extern int fscache_wait_bit(void *);
extern int fscache_wait_bit_interruptible(void *);
+extern int fscache_wait_atomic_t(atomic_t *);
/*
* object.c
@@ -106,8 +107,10 @@ extern void fscache_enqueue_object(struct fscache_object *);
extern const struct file_operations fscache_objlist_fops;
extern void fscache_objlist_add(struct fscache_object *);
+extern void fscache_objlist_remove(struct fscache_object *);
#else
#define fscache_objlist_add(object) do {} while(0)
+#define fscache_objlist_remove(object) do {} while(0)
#endif
/*
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index f9d856773f79..7c27907e650c 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -205,7 +205,6 @@ int fscache_wait_bit(void *flags)
schedule();
return 0;
}
-EXPORT_SYMBOL(fscache_wait_bit);
/*
* wait_on_bit() sleep function for interruptible waiting
@@ -215,4 +214,12 @@ int fscache_wait_bit_interruptible(void *flags)
schedule();
return signal_pending(current);
}
-EXPORT_SYMBOL(fscache_wait_bit_interruptible);
+
+/*
+ * wait_on_atomic_t() sleep function for uninterruptible waiting
+ */
+int fscache_wait_atomic_t(atomic_t *p)
+{
+ schedule();
+ return 0;
+}
diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index e028b8eb1c40..b1bb6117473a 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -40,6 +40,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
/* initialise the primary index cookie */
atomic_set(&netfs->primary_index->usage, 1);
atomic_set(&netfs->primary_index->n_children, 0);
+ atomic_set(&netfs->primary_index->n_active, 1);
netfs->primary_index->def = &fscache_fsdef_netfs_def;
netfs->primary_index->parent = &fscache_fsdef_index;
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index 4a386b080e03..e1959efad64f 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -70,13 +70,10 @@ void fscache_objlist_add(struct fscache_object *obj)
write_unlock(&fscache_object_list_lock);
}
-/**
- * fscache_object_destroy - Note that a cache object is about to be destroyed
- * @object: The object to be destroyed
- *
- * Note the imminent destruction and deallocation of a cache object record.
+/*
+ * Remove an object from the object list.
*/
-void fscache_object_destroy(struct fscache_object *obj)
+void fscache_objlist_remove(struct fscache_object *obj)
{
write_lock(&fscache_object_list_lock);
@@ -85,7 +82,6 @@ void fscache_object_destroy(struct fscache_object *obj)
write_unlock(&fscache_object_list_lock);
}
-EXPORT_SYMBOL(fscache_object_destroy);
/*
* find the object in the tree on or after the specified index
@@ -166,10 +162,9 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
{
struct fscache_objlist_data *data = m->private;
struct fscache_object *obj = v;
+ struct fscache_cookie *cookie;
unsigned long config = data->config;
- uint16_t keylen, auxlen;
char _type[3], *type;
- bool no_cookie;
u8 *buf = data->buf, *p;
if ((unsigned long) v == 1) {
@@ -216,8 +211,9 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
} \
} while(0)
+ cookie = obj->cookie;
if (~config) {
- FILTER(obj->cookie,
+ FILTER(cookie->def,
COOKIE, NOCOOKIE);
FILTER(fscache_object_is_active(obj) ||
obj->n_ops != 0 ||
@@ -250,48 +246,40 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
obj->flags,
work_busy(&obj->work));
- no_cookie = true;
- keylen = auxlen = 0;
- if (obj->cookie) {
- spin_lock(&obj->lock);
- if (obj->cookie) {
- switch (obj->cookie->def->type) {
- case 0:
- type = "IX";
- break;
- case 1:
- type = "DT";
- break;
- default:
- sprintf(_type, "%02u",
- obj->cookie->def->type);
- type = _type;
- break;
- }
+ if (fscache_use_cookie(obj)) {
+ uint16_t keylen = 0, auxlen = 0;
- seq_printf(m, "%-16s %s %2lx %16p",
- obj->cookie->def->name,
- type,
- obj->cookie->flags,
- obj->cookie->netfs_data);
-
- if (obj->cookie->def->get_key &&
- config & FSCACHE_OBJLIST_CONFIG_KEY)
- keylen = obj->cookie->def->get_key(
- obj->cookie->netfs_data,
- buf, 400);
-
- if (obj->cookie->def->get_aux &&
- config & FSCACHE_OBJLIST_CONFIG_AUX)
- auxlen = obj->cookie->def->get_aux(
- obj->cookie->netfs_data,
- buf + keylen, 512 - keylen);
-
- no_cookie = false;
+ switch (cookie->def->type) {
+ case 0:
+ type = "IX";
+ break;
+ case 1:
+ type = "DT";
+ break;
+ default:
+ sprintf(_type, "%02u", cookie->def->type);
+ type = _type;
+ break;
}
- spin_unlock(&obj->lock);
- if (!no_cookie && (keylen > 0 || auxlen > 0)) {
+ seq_printf(m, "%-16s %s %2lx %16p",
+ cookie->def->name,
+ type,
+ cookie->flags,
+ cookie->netfs_data);
+
+ if (cookie->def->get_key &&
+ config & FSCACHE_OBJLIST_CONFIG_KEY)
+ keylen = cookie->def->get_key(cookie->netfs_data,
+ buf, 400);
+
+ if (cookie->def->get_aux &&
+ config & FSCACHE_OBJLIST_CONFIG_AUX)
+ auxlen = cookie->def->get_aux(cookie->netfs_data,
+ buf + keylen, 512 - keylen);
+ fscache_unuse_cookie(obj);
+
+ if (keylen > 0 || auxlen > 0) {
seq_printf(m, " ");
for (p = buf; keylen > 0; keylen--)
seq_printf(m, "%02x", *p++);
@@ -302,12 +290,11 @@ static int fscache_objlist_show(struct seq_file *m, void *v)
seq_printf(m, "%02x", *p++);
}
}
- }
- if (no_cookie)
- seq_printf(m, "<no_cookie>\n");
- else
seq_printf(m, "\n");
+ } else {
+ seq_printf(m, "<no_netfs>\n");
+ }
return 0;
}
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 8f17debd7979..86d75a60b20c 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -30,7 +30,6 @@ static const struct fscache_state *fscache_look_up_object(struct fscache_object
static const struct fscache_state *fscache_object_available(struct fscache_object *, int);
static const struct fscache_state *fscache_parent_ready(struct fscache_object *, int);
static const struct fscache_state *fscache_update_object(struct fscache_object *, int);
-static const struct fscache_state *fscache_detach_from_cookie(struct fscache_object *, int);
#define __STATE_NAME(n) fscache_osm_##n
#define STATE(n) (&__STATE_NAME(n))
@@ -92,7 +91,6 @@ static WORK_STATE(LOOKUP_FAILURE, "LCFL", fscache_lookup_failure);
static WORK_STATE(KILL_OBJECT, "KILL", fscache_kill_object);
static WORK_STATE(KILL_DEPENDENTS, "KDEP", fscache_kill_dependents);
static WORK_STATE(DROP_OBJECT, "DROP", fscache_drop_object);
-static WORK_STATE(DETACH_FROM_COOKIE, "DTCH", fscache_detach_from_cookie);
static WORK_STATE(OBJECT_DEAD, "DEAD", (void*)2UL);
static WAIT_STATE(WAIT_FOR_INIT, "?INI",
@@ -156,8 +154,8 @@ static inline void fscache_done_parent_op(struct fscache_object *object)
object->debug_id, parent->debug_id, parent->n_ops);
spin_lock_nested(&parent->lock, 1);
- parent->n_ops--;
parent->n_obj_ops--;
+ parent->n_ops--;
if (parent->n_ops == 0)
fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&parent->lock);
@@ -332,22 +330,10 @@ EXPORT_SYMBOL(fscache_object_init);
static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *object,
int event)
{
- struct fscache_cookie *cookie;
-
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_event_mask = 0;
- clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
-
fscache_dequeue_object(object);
-
- spin_lock(&object->lock);
- cookie = object->cookie;
- clear_bit_unlock(FSCACHE_COOKIE_CREATING, &cookie->flags);
- spin_unlock(&object->lock);
-
- wake_up_bit(&cookie->flags, FSCACHE_COOKIE_CREATING);
-
return transit_to(KILL_OBJECT);
}
@@ -357,8 +343,6 @@ static const struct fscache_state *fscache_abort_initialisation(struct fscache_o
* immediately to do a creation
* - we may need to start the process of creating a parent and we need to wait
* for the parent's lookup and creation to complete if it's not there yet
- * - an object's cookie is pinned until we clear FSCACHE_COOKIE_CREATING on the
- * leaf-most cookies of the object and all its children
*/
static const struct fscache_state *fscache_initialise_object(struct fscache_object *object,
int event)
@@ -373,14 +357,14 @@ static const struct fscache_state *fscache_initialise_object(struct fscache_obje
parent = object->parent;
if (!parent) {
_leave(" [no parent]");
- return transit_to(DETACH_FROM_COOKIE);
+ return transit_to(DROP_OBJECT);
}
- _debug("parent %s", parent->state->name);
+ _debug("parent: %s of:%lx", parent->state->name, parent->flags);
if (fscache_object_is_dying(parent)) {
_leave(" [bad parent]");
- return transit_to(DETACH_FROM_COOKIE);
+ return transit_to(DROP_OBJECT);
}
if (fscache_object_is_available(parent)) {
@@ -402,7 +386,7 @@ static const struct fscache_state *fscache_initialise_object(struct fscache_obje
spin_unlock(&parent->lock);
if (!success) {
_leave(" [grab failed]");
- return transit_to(DETACH_FROM_COOKIE);
+ return transit_to(DROP_OBJECT);
}
/* fscache_acquire_non_index_cookie() uses this
@@ -438,8 +422,6 @@ static const struct fscache_state *fscache_parent_ready(struct fscache_object *o
* look an object up in the cache from which it was allocated
* - we hold an "access lock" on the parent object, so the parent object cannot
* be withdrawn by either party till we've finished
- * - an object's cookie is pinned until we clear FSCACHE_COOKIE_CREATING on the
- * leaf-most cookies of the object and all its children
*/
static const struct fscache_state *fscache_look_up_object(struct fscache_object *object,
int event)
@@ -460,22 +442,21 @@ static const struct fscache_state *fscache_look_up_object(struct fscache_object
ASSERT(fscache_object_is_available(parent));
if (fscache_object_is_dying(parent) ||
- test_bit(FSCACHE_IOERROR, &object->cache->flags)) {
+ test_bit(FSCACHE_IOERROR, &object->cache->flags) ||
+ !fscache_use_cookie(object)) {
_leave(" [unavailable]");
return transit_to(LOOKUP_FAILURE);
}
- _debug("LOOKUP \"%s/%s\" in \"%s\"",
- parent->cookie->def->name, cookie->def->name,
- object->cache->tag->name);
+ _debug("LOOKUP \"%s\" in \"%s\"",
+ cookie->def->name, object->cache->tag->name);
fscache_stat(&fscache_n_object_lookups);
fscache_stat(&fscache_n_cop_lookup_object);
ret = object->cache->ops->lookup_object(object);
fscache_stat_d(&fscache_n_cop_lookup_object);
- if (test_bit(FSCACHE_OBJECT_EV_ERROR, &object->events))
- set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
+ fscache_unuse_cookie(object);
if (ret == -ETIMEDOUT) {
/* probably stuck behind another object, so move this one to
@@ -557,11 +538,6 @@ void fscache_obtained_object(struct fscache_object *object)
}
set_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
-
- /* Permit __fscache_relinquish_cookie() to proceed */
- clear_bit_unlock(FSCACHE_COOKIE_CREATING, &cookie->flags);
- wake_up_bit(&cookie->flags, FSCACHE_COOKIE_CREATING);
-
_leave("");
}
EXPORT_SYMBOL(fscache_obtained_object);
@@ -572,16 +548,12 @@ EXPORT_SYMBOL(fscache_obtained_object);
static const struct fscache_state *fscache_object_available(struct fscache_object *object,
int event)
{
- struct fscache_cookie *cookie = object->cookie;
-
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_table = fscache_osm_run_oob;
spin_lock(&object->lock);
- ASSERTIF(cookie, !test_bit(FSCACHE_COOKIE_CREATING, &object->cookie->flags));
-
fscache_done_parent_op(object);
if (object->n_in_progress == 0) {
if (object->n_ops > 0) {
@@ -624,7 +596,6 @@ static const struct fscache_state *fscache_lookup_failure(struct fscache_object
int event)
{
struct fscache_cookie *cookie;
- bool wake_looking_up = false;
_enter("{OBJ%x},%d", object->debug_id, event);
@@ -634,19 +605,10 @@ static const struct fscache_state *fscache_lookup_failure(struct fscache_object
object->cache->ops->lookup_complete(object);
fscache_stat_d(&fscache_n_cop_lookup_complete);
- spin_lock(&object->lock);
cookie = object->cookie;
set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
- if (cookie) {
- if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
- wake_looking_up = true;
- clear_bit_unlock(FSCACHE_COOKIE_CREATING, &cookie->flags);
- }
- spin_unlock(&object->lock);
-
- if (wake_looking_up)
+ if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
- wake_up_bit(&cookie->flags, FSCACHE_COOKIE_CREATING);
fscache_done_parent_op(object);
return transit_to(KILL_OBJECT);
@@ -662,21 +624,20 @@ static const struct fscache_state *fscache_kill_object(struct fscache_object *ob
_enter("{OBJ%x,%d,%d},%d",
object->debug_id, object->n_ops, object->n_children, event);
- object->oob_event_mask = 0;
-
- spin_lock(&object->lock);
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
- spin_unlock(&object->lock);
+ object->oob_event_mask = 0;
if (list_empty(&object->dependents) &&
object->n_ops == 0 &&
object->n_children == 0)
- return object->cookie ?
- transit_to(DETACH_FROM_COOKIE) : transit_to(DROP_OBJECT);
+ return transit_to(DROP_OBJECT);
- spin_lock(&object->lock);
- fscache_start_operations(object);
- spin_unlock(&object->lock);
+ if (object->n_in_progress == 0) {
+ spin_lock(&object->lock);
+ if (object->n_ops > 0 && object->n_in_progress == 0)
+ fscache_start_operations(object);
+ spin_unlock(&object->lock);
+ }
if (!list_empty(&object->dependents))
return transit_to(KILL_DEPENDENTS);
@@ -697,52 +658,6 @@ static const struct fscache_state *fscache_kill_dependents(struct fscache_object
return transit_to(WAIT_FOR_CLEARANCE);
}
-/*
- * withdraw an object from active service
- */
-static const struct fscache_state *fscache_detach_from_cookie(struct fscache_object *object,
- int event)
-{
- struct fscache_cookie *cookie;
- bool detached = false, awaken = false;
-
- _enter("{OBJ%x},%d", object->debug_id, event);
-
- spin_lock(&object->lock);
- cookie = object->cookie;
- if (cookie) {
- /* need to get the cookie lock before the object lock, starting
- * from the object pointer */
- atomic_inc(&cookie->usage);
- spin_unlock(&object->lock);
-
- spin_lock(&cookie->lock);
- spin_lock(&object->lock);
-
- if (object->cookie == cookie) {
- hlist_del_init(&object->cookie_link);
- object->cookie = NULL;
- if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING,
- &cookie->flags))
- awaken = true;
- detached = true;
- }
- spin_unlock(&cookie->lock);
- fscache_cookie_put(cookie);
- if (detached)
- fscache_cookie_put(cookie);
- }
-
- spin_unlock(&object->lock);
-
- if (awaken)
- wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
-
- fscache_stat(&fscache_n_object_dead);
- _leave("");
- return transit_to(DROP_OBJECT);
-}
-
/*
* Drop an object's attachments
*/
@@ -750,12 +665,26 @@ static const struct fscache_state *fscache_drop_object(struct fscache_object *ob
int event)
{
struct fscache_object *parent = object->parent;
+ struct fscache_cookie *cookie = object->cookie;
struct fscache_cache *cache = object->cache;
+ bool awaken = false;
_enter("{OBJ%x,%d},%d", object->debug_id, object->n_children, event);
- ASSERTCMP(object->cookie, ==, NULL);
- ASSERT(hlist_unhashed(&object->cookie_link));
+ ASSERT(cookie != NULL);
+ ASSERT(!hlist_unhashed(&object->cookie_link));
+
+ /* Make sure the cookie no longer points here and that the netfs isn't
+ * waiting for us.
+ */
+ spin_lock(&cookie->lock);
+ hlist_del_init(&object->cookie_link);
+ 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);
/* Prevent a race with our last child, which has to signal EV_CLEARED
* before dropping our spinlock.
@@ -816,6 +745,22 @@ static void fscache_put_object(struct fscache_object *object)
fscache_stat_d(&fscache_n_cop_put_object);
}
+/**
+ * fscache_object_destroy - Note that a cache object is about to be destroyed
+ * @object: The object to be destroyed
+ *
+ * Note the imminent destruction and deallocation of a cache object record.
+ */
+void fscache_object_destroy(struct fscache_object *object)
+{
+ fscache_objlist_remove(object);
+
+ /* We can get rid of the cookie now */
+ fscache_cookie_put(object->cookie);
+ object->cookie = NULL;
+}
+EXPORT_SYMBOL(fscache_object_destroy);
+
/*
* enqueue an object for metadata-type processing
*/
@@ -925,7 +870,10 @@ static void fscache_dequeue_object(struct fscache_object *object)
* @data: The auxiliary data for the object
* @datalen: The size of the auxiliary data
*
- * This function consults the netfs about the coherency state of an object
+ * This function consults the netfs about the coherency state of an object.
+ * The caller must be holding a ref on cookie->n_active (held by
+ * fscache_look_up_object() on behalf of the cache backend during object lookup
+ * and creation).
*/
enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data, uint16_t datalen)
@@ -974,6 +922,15 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj
_enter("{OBJ%x},%d", object->debug_id, event);
+ /* We're going to need the cookie. If the cookie is not available then
+ * retire the object instead.
+ */
+ if (!fscache_use_cookie(object)) {
+ ASSERT(object->cookie->stores.rnode == NULL);
+ set_bit(FSCACHE_COOKIE_RETIRED, &cookie->flags);
+ _leave(" [no cookie]");
+ return transit_to(KILL_OBJECT);
+ }
/* Reject any new read/write ops and abort any that are pending. */
fscache_invalidate_writes(cookie);
@@ -982,14 +939,13 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj
/* Now we have to wait for in-progress reads and writes */
op = kzalloc(sizeof(*op), GFP_KERNEL);
- if (!op) {
- clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
- _leave(" [ENOMEM]");
- return transit_to(KILL_OBJECT);
- }
+ if (!op)
+ goto nomem;
fscache_operation_init(op, object->cache->ops->invalidate_object, 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 (fscache_submit_exclusive_op(object, op) < 0)
@@ -1011,6 +967,12 @@ static const struct fscache_state *_fscache_invalidate_object(struct fscache_obj
_leave(" [ok]");
return transit_to(UPDATE_OBJECT);
+nomem:
+ clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
+ fscache_unuse_cookie(object);
+ _leave(" [ENOMEM]");
+ return transit_to(KILL_OBJECT);
+
submit_op_failed:
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
spin_unlock(&cookie->lock);
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index 4da211b21ddf..6935901bce38 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -424,14 +424,10 @@ void fscache_put_operation(struct fscache_operation *op)
object = op->object;
- if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags)) {
- if (atomic_dec_and_test(&object->n_reads)) {
- clear_bit(FSCACHE_COOKIE_WAITING_ON_READS,
- &object->cookie->flags);
- wake_up_bit(&object->cookie->flags,
- FSCACHE_COOKIE_WAITING_ON_READS);
- }
- }
+ if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
+ atomic_dec(&object->n_reads);
+ if (test_bit(FSCACHE_OP_UNUSE_COOKIE, &op->flags))
+ fscache_unuse_cookie(object);
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index b4e4b424160a..780bac6ffde5 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -163,10 +163,12 @@ static void fscache_attr_changed_op(struct fscache_operation *op)
fscache_stat(&fscache_n_attr_changed_calls);
- if (fscache_object_is_active(object)) {
+ if (fscache_object_is_active(object) &&
+ fscache_use_cookie(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);
}
@@ -246,6 +248,7 @@ static void fscache_release_retrieval_op(struct fscache_operation *_op)
* allocate a retrieval op
*/
static struct fscache_retrieval *fscache_alloc_retrieval(
+ struct fscache_cookie *cookie,
struct address_space *mapping,
fscache_rw_complete_t end_io_func,
void *context)
@@ -260,7 +263,10 @@ static struct fscache_retrieval *fscache_alloc_retrieval(
}
fscache_operation_init(&op->op, NULL, fscache_release_retrieval_op);
- op->op.flags = FSCACHE_OP_MYTHREAD | (1 << FSCACHE_OP_WAITING);
+ atomic_inc(&cookie->n_active);
+ op->op.flags = FSCACHE_OP_MYTHREAD |
+ (1UL << FSCACHE_OP_WAITING) |
+ (1UL << FSCACHE_OP_UNUSE_COOKIE);
op->mapping = mapping;
op->end_io_func = end_io_func;
op->context = context;
@@ -394,7 +400,8 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
- op = fscache_alloc_retrieval(page->mapping, end_io_func, context);
+ op = fscache_alloc_retrieval(cookie, page->mapping,
+ end_io_func,context);
if (!op) {
_leave(" = -ENOMEM");
return -ENOMEM;
@@ -465,6 +472,7 @@ nobufs_unlock_dec:
atomic_dec(&object->n_reads);
nobufs_unlock:
spin_unlock(&cookie->lock);
+ atomic_dec(&cookie->n_active);
kfree(op);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
@@ -522,7 +530,7 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
- op = fscache_alloc_retrieval(mapping, end_io_func, context);
+ op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context);
if (!op)
return -ENOMEM;
op->n_pages = *nr_pages;
@@ -589,6 +597,7 @@ nobufs_unlock_dec:
atomic_dec(&object->n_reads);
nobufs_unlock:
spin_unlock(&cookie->lock);
+ atomic_dec(&cookie->n_active);
kfree(op);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
@@ -631,7 +640,7 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
- op = fscache_alloc_retrieval(page->mapping, NULL, NULL);
+ op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL);
if (!op)
return -ENOMEM;
op->n_pages = 1;
@@ -675,6 +684,7 @@ error:
nobufs_unlock:
spin_unlock(&cookie->lock);
+ atomic_dec(&cookie->n_active);
kfree(op);
nobufs:
fscache_stat(&fscache_n_allocs_nobufs);
@@ -876,7 +886,9 @@ int __fscache_write_page(struct fscache_cookie *cookie,
fscache_operation_init(&op->op, fscache_write_op,
fscache_release_write_op);
- op->op.flags = FSCACHE_OP_ASYNC | (1 << FSCACHE_OP_WAITING);
+ op->op.flags = FSCACHE_OP_ASYNC |
+ (1 << FSCACHE_OP_WAITING) |
+ (1 << FSCACHE_OP_UNUSE_COOKIE);
ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM);
if (ret < 0)
@@ -922,6 +934,7 @@ 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);
if (fscache_submit_op(object, &op->op) < 0)
goto submit_failed;
@@ -948,6 +961,7 @@ 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);