1 files changed, 72 insertions, 0 deletions

diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 773bc798a416..80b549141ea6 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -14,6 +14,7 @@
 
 #define FSCACHE_DEBUG_LEVEL COOKIE
 #include <linux/module.h>
+#include <linux/slab.h>
 #include "internal.h"
 
 const char *fscache_object_states[FSCACHE_OBJECT__NSTATES] = {
@@ -22,6 +23,7 @@ const char *fscache_object_states[FSCACHE_OBJECT__NSTATES] = {
         [FSCACHE_OBJECT_CREATING]       = "OBJECT_CREATING",
         [FSCACHE_OBJECT_AVAILABLE]      = "OBJECT_AVAILABLE",
         [FSCACHE_OBJECT_ACTIVE]         = "OBJECT_ACTIVE",
+        [FSCACHE_OBJECT_INVALIDATING]   = "OBJECT_INVALIDATING",
         [FSCACHE_OBJECT_UPDATING]       = "OBJECT_UPDATING",
         [FSCACHE_OBJECT_DYING]          = "OBJECT_DYING",
         [FSCACHE_OBJECT_LC_DYING]       = "OBJECT_LC_DYING",
@@ -39,6 +41,7 @@ const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5] = {
         [FSCACHE_OBJECT_CREATING]       = "CRTN",
         [FSCACHE_OBJECT_AVAILABLE]      = "AVBL",
         [FSCACHE_OBJECT_ACTIVE]         = "ACTV",
+        [FSCACHE_OBJECT_INVALIDATING]   = "INVL",
         [FSCACHE_OBJECT_UPDATING]       = "UPDT",
         [FSCACHE_OBJECT_DYING]          = "DYNG",
         [FSCACHE_OBJECT_LC_DYING]       = "LCDY",
@@ -54,6 +57,7 @@ static void fscache_put_object(struct fscache_object *);
 static void fscache_initialise_object(struct fscache_object *);
 static void fscache_lookup_object(struct fscache_object *);
 static void fscache_object_available(struct fscache_object *);
+static void fscache_invalidate_object(struct fscache_object *);
 static void fscache_release_object(struct fscache_object *);
 static void fscache_withdraw_object(struct fscache_object *);
 static void fscache_enqueue_dependents(struct fscache_object *);
@@ -79,6 +83,15 @@ static inline void fscache_done_parent_op(struct fscache_object *object)
 }
 
 /*
+ * Notify netfs of invalidation completion.
+ */
+static inline void fscache_invalidation_complete(struct fscache_cookie *cookie)
+{
+        if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
+                wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
+}
+
+/*
  * process events that have been sent to an object's state machine
  * - initiates parent lookup
  * - does object lookup
@@ -125,6 +138,16 @@ static void fscache_object_state_machine(struct fscache_object *object)
         case FSCACHE_OBJECT_ACTIVE:
                 goto active_transit;
 
+                /* Invalidate an object on disk */
+        case FSCACHE_OBJECT_INVALIDATING:
+                clear_bit(FSCACHE_OBJECT_EV_INVALIDATE, &object->events);
+                fscache_stat(&fscache_n_invalidates_run);
+                fscache_stat(&fscache_n_cop_invalidate_object);
+                fscache_invalidate_object(object);
+                fscache_stat_d(&fscache_n_cop_invalidate_object);
+                fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE);
+                goto active_transit;
+
                 /* update the object metadata on disk */
         case FSCACHE_OBJECT_UPDATING:
                 clear_bit(FSCACHE_OBJECT_EV_UPDATE, &object->events);
@@ -275,6 +298,9 @@ active_transit:
         case FSCACHE_OBJECT_EV_ERROR:
                 new_state = FSCACHE_OBJECT_DYING;
                 goto change_state;
+        case FSCACHE_OBJECT_EV_INVALIDATE:
+                new_state = FSCACHE_OBJECT_INVALIDATING;
+                goto change_state;
         case FSCACHE_OBJECT_EV_UPDATE:
                 new_state = FSCACHE_OBJECT_UPDATING;
                 goto change_state;
@@ -679,6 +705,7 @@ static void fscache_withdraw_object(struct fscache_object *object)
                 if (object->cookie == cookie) {
                         hlist_del_init(&object->cookie_link);
                         object->cookie = NULL;
+                        fscache_invalidation_complete(cookie);
                         detached = true;
                 }
                 spin_unlock(&cookie->lock);
@@ -888,3 +915,48 @@ enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
         return result;
 }
 EXPORT_SYMBOL(fscache_check_aux);
+
+/*
+ * Asynchronously invalidate an object.
+ */
+static void fscache_invalidate_object(struct fscache_object *object)
+{
+        struct fscache_operation *op;
+        struct fscache_cookie *cookie = object->cookie;
+
+        _enter("{OBJ%x}", object->debug_id);
+
+        /* Reject any new read/write ops and abort any that are pending. */
+        fscache_invalidate_writes(cookie);
+        clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
+        fscache_cancel_all_ops(object);
+
+        /* Now we have to wait for in-progress reads and writes */
+        op = kzalloc(sizeof(*op), GFP_KERNEL);
+        if (!op) {
+                fscache_raise_event(object, FSCACHE_OBJECT_EV_ERROR);
+                _leave(" [ENOMEM]");
+                return;
+        }
+
+        fscache_operation_init(op, object->cache->ops->invalidate_object, NULL);
+        op->flags = FSCACHE_OP_ASYNC | (1 << FSCACHE_OP_EXCLUSIVE);
+
+        spin_lock(&cookie->lock);
+        if (fscache_submit_exclusive_op(object, op) < 0)
+                BUG();
+        spin_unlock(&cookie->lock);
+        fscache_put_operation(op);
+
+        /* Once we've completed the invalidation, we know there will be no data
+         * stored in the cache and thus we can reinstate the data-check-skip
+         * optimisation.
+         */
+        set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
+
+        /* We can allow read and write requests to come in once again.  They'll
+         * queue up behind our exclusive invalidation operation.
+         */
+        fscache_invalidation_complete(cookie);
+        _leave("");
+}