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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 10:30:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 10:30:56 -0800
commit2883aaea363f7a897ff06d2e6c73ae7aae285bcb (patch)
treec4b53cd7231612df4a3b1ac190d205f6618bdbcd
parente387dc122fc7c70c2a5df2567f4e2d1114f5a5da (diff)
parente26bfebdfc0d212d366de9990a096665d5c0209a (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fscache fixes from Al Viro. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fscache: Fix dead object requeue fscache: Clear outstanding writes when disabling a cookie FS-Cache: Initialise stores_lock in netfs cookie
-rw-r--r--fs/fscache/cookie.c5
-rw-r--r--fs/fscache/netfs.c1
-rw-r--r--fs/fscache/object.c32
-rw-r--r--include/linux/fscache-cache.h1
4 files changed, 37 insertions, 2 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 4304072161aa..40d61077bead 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -542,6 +542,7 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) {
if (invalidate)
set_bit(FSCACHE_OBJECT_RETIRED, &object->flags);
+ clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
}
} else {
@@ -560,6 +561,10 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
wait_on_atomic_t(&cookie->n_active, fscache_wait_atomic_t,
TASK_UNINTERRUPTIBLE);
+ /* Make sure any pending writes are cancelled. */
+ if (cookie->def->type != FSCACHE_COOKIE_TYPE_INDEX)
+ fscache_invalidate_writes(cookie);
+
/* Reset the cookie state if it wasn't relinquished */
if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) {
atomic_inc(&cookie->n_active);
diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index 9b28649df3a1..a8aa00be4444 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -48,6 +48,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
cookie->flags = 1 << FSCACHE_COOKIE_ENABLED;
spin_lock_init(&cookie->lock);
+ spin_lock_init(&cookie->stores_lock);
INIT_HLIST_HEAD(&cookie->backing_objects);
/* check the netfs type is not already present */
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 9e792e30f4db..7a182c87f378 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -30,6 +30,7 @@ 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_object_dead(struct fscache_object *, int);
#define __STATE_NAME(n) fscache_osm_##n
#define STATE(n) (&__STATE_NAME(n))
@@ -91,7 +92,7 @@ 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(OBJECT_DEAD, "DEAD", (void*)2UL);
+static WORK_STATE(OBJECT_DEAD, "DEAD", fscache_object_dead);
static WAIT_STATE(WAIT_FOR_INIT, "?INI",
TRANSIT_TO(INIT_OBJECT, 1 << FSCACHE_OBJECT_EV_NEW_CHILD));
@@ -229,6 +230,10 @@ execute_work_state:
event = -1;
if (new_state == NO_TRANSIT) {
_debug("{OBJ%x} %s notrans", object->debug_id, state->name);
+ if (unlikely(state == STATE(OBJECT_DEAD))) {
+ _leave(" [dead]");
+ return;
+ }
fscache_enqueue_object(object);
event_mask = object->oob_event_mask;
goto unmask_events;
@@ -239,7 +244,7 @@ execute_work_state:
object->state = state = new_state;
if (state->work) {
- if (unlikely(state->work == ((void *)2UL))) {
+ if (unlikely(state == STATE(OBJECT_DEAD))) {
_leave(" [dead]");
return;
}
@@ -645,6 +650,12 @@ static const struct fscache_state *fscache_kill_object(struct fscache_object *ob
fscache_mark_object_dead(object);
object->oob_event_mask = 0;
+ if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) {
+ /* Reject any new read/write ops and abort any that are pending. */
+ clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
+ fscache_cancel_all_ops(object);
+ }
+
if (list_empty(&object->dependents) &&
object->n_ops == 0 &&
object->n_children == 0)
@@ -1077,3 +1088,20 @@ void fscache_object_mark_killed(struct fscache_object *object,
}
}
EXPORT_SYMBOL(fscache_object_mark_killed);
+
+/*
+ * The object is dead. We can get here if an object gets queued by an event
+ * that would lead to its death (such as EV_KILL) when the dispatcher is
+ * already running (and so can be requeued) but hasn't yet cleared the event
+ * mask.
+ */
+static const struct fscache_state *fscache_object_dead(struct fscache_object *object,
+ int event)
+{
+ if (!test_and_set_bit(FSCACHE_OBJECT_RUN_AFTER_DEAD,
+ &object->flags))
+ return NO_TRANSIT;
+
+ WARN(true, "FS-Cache object redispatched after death");
+ return NO_TRANSIT;
+}
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 13ba552e6c09..4c467ef50159 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -360,6 +360,7 @@ struct fscache_object {
#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */
#define FSCACHE_OBJECT_RETIRED 6 /* T if object was retired on relinquishment */
#define FSCACHE_OBJECT_KILLED_BY_CACHE 7 /* T if object was killed by the cache */
+#define FSCACHE_OBJECT_RUN_AFTER_DEAD 8 /* T if object has been dispatched after death */
struct list_head cache_link; /* link in cache->object_list */
struct hlist_node cookie_link; /* link in cookie->backing_objects */