1 files changed, 55 insertions, 57 deletions

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index fc76798bd968..c598ea4c4e7d 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -314,6 +314,43 @@ static int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
 }
 
 /*
+ * wait for an object to become active (or dead)
+ */
+static int fscache_wait_for_retrieval_activation(struct fscache_object *object,
+                                                 struct fscache_retrieval *op,
+                                                 atomic_t *stat_op_waits,
+                                                 atomic_t *stat_object_dead)
+{
+        int ret;
+
+        if (!test_bit(FSCACHE_OP_WAITING, &op->op.flags))
+                goto check_if_dead;
+
+        _debug(">>> WT");
+        fscache_stat(stat_op_waits);
+        if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
+                        fscache_wait_bit_interruptible,
+                        TASK_INTERRUPTIBLE) < 0) {
+                ret = fscache_cancel_op(&op->op);
+                if (ret == 0)
+                        return -ERESTARTSYS;
+
+                /* it's been removed from the pending queue by another party,
+                 * so we should get to run shortly */
+                wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
+                            fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+        }
+        _debug("<<< GO");
+
+check_if_dead:
+        if (unlikely(fscache_object_is_dead(object))) {
+                fscache_stat(stat_object_dead);
+                return -ENOBUFS;
+        }
+        return 0;
+}
+
+/*
  * read a page from the cache or allocate a block in which to store it
  * - we return:
  *   -ENOMEM    - out of memory, nothing done
@@ -376,25 +413,12 @@ int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
 
         /* we wait for the operation to become active, and then process it
          * *here*, in this thread, and not in the thread pool */
-        if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) {
-                _debug(">>> WT");
-                fscache_stat(&fscache_n_retrieval_op_waits);
-                if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                fscache_wait_bit_interruptible,
-                                TASK_INTERRUPTIBLE) < 0) {
-                        ret = fscache_cancel_op(&op->op);
-                        if (ret == 0) {
-                                ret = -ERESTARTSYS;
-                                goto error;
-                        }
-
-                        /* it's been removed from the pending queue by another
-                         * party, so we should get to run shortly */
-                        wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                    fscache_wait_bit, TASK_UNINTERRUPTIBLE);
-                }
-                _debug("<<< GO");
-        }
+        ret = fscache_wait_for_retrieval_activation(
+                object, op,
+                __fscache_stat(&fscache_n_retrieval_op_waits),
+                __fscache_stat(&fscache_n_retrievals_object_dead));
+        if (ret < 0)
+                goto error;
 
         /* ask the cache to honour the operation */
         if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
@@ -506,25 +530,12 @@ int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
 
         /* we wait for the operation to become active, and then process it
          * *here*, in this thread, and not in the thread pool */
-        if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) {
-                _debug(">>> WT");
-                fscache_stat(&fscache_n_retrieval_op_waits);
-                if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                fscache_wait_bit_interruptible,
-                                TASK_INTERRUPTIBLE) < 0) {
-                        ret = fscache_cancel_op(&op->op);
-                        if (ret == 0) {
-                                ret = -ERESTARTSYS;
-                                goto error;
-                        }
-
-                        /* it's been removed from the pending queue by another
-                         * party, so we should get to run shortly */
-                        wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                    fscache_wait_bit, TASK_UNINTERRUPTIBLE);
-                }
-                _debug("<<< GO");
-        }
+        ret = fscache_wait_for_retrieval_activation(
+                object, op,
+                __fscache_stat(&fscache_n_retrieval_op_waits),
+                __fscache_stat(&fscache_n_retrievals_object_dead));
+        if (ret < 0)
+                goto error;
 
         /* ask the cache to honour the operation */
         if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
@@ -612,25 +623,12 @@ int __fscache_alloc_page(struct fscache_cookie *cookie,
 
         fscache_stat(&fscache_n_alloc_ops);
 
-        if (test_bit(FSCACHE_OP_WAITING, &op->op.flags)) {
-                _debug(">>> WT");
-                fscache_stat(&fscache_n_alloc_op_waits);
-                if (wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                fscache_wait_bit_interruptible,
-                                TASK_INTERRUPTIBLE) < 0) {
-                        ret = fscache_cancel_op(&op->op);
-                        if (ret == 0) {
-                                ret = -ERESTARTSYS;
-                                goto error;
-                        }
-
-                        /* it's been removed from the pending queue by another
-                         * party, so we should get to run shortly */
-                        wait_on_bit(&op->op.flags, FSCACHE_OP_WAITING,
-                                    fscache_wait_bit, TASK_UNINTERRUPTIBLE);
-                }
-                _debug("<<< GO");
-        }
+        ret = fscache_wait_for_retrieval_activation(
+                object, op,
+                __fscache_stat(&fscache_n_alloc_op_waits),
+                __fscache_stat(&fscache_n_allocs_object_dead));
+        if (ret < 0)
+                goto error;
 
         /* ask the cache to honour the operation */
         fscache_stat(&fscache_n_cop_allocate_page);