6 files changed, 75 insertions, 61 deletions

diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt
index 7097fd29fb3d..3c23411956bb 100644
--- a/Documentation/filesystems/caching/fscache.txt
+++ b/Documentation/filesystems/caching/fscache.txt
@@ -253,6 +253,7 @@ proc files.
                 int=N   Number of alloc reqs aborted -ERESTARTSYS
                 ops=N   Number of alloc reqs submitted
                 owt=N   Number of alloc reqs waited for CPU time
+                abt=N   Number of alloc reqs aborted due to object death
         Retrvls n=N     Number of retrieval (read) requests seen
                 ok=N    Number of successful retr reqs
                 wt=N    Number of retr reqs that waited on lookup completion
@@ -262,6 +263,7 @@ proc files.
                 oom=N   Number of retr reqs failed -ENOMEM
                 ops=N   Number of retr reqs submitted
                 owt=N   Number of retr reqs waited for CPU time
+                abt=N   Number of retr reqs aborted due to object death
         Stores  n=N     Number of storage (write) requests seen
                 ok=N    Number of successful store reqs
                 agn=N   Number of store reqs on a page already pending storage
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 2bf463d26080..5b49a373689b 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -156,6 +156,7 @@ extern atomic_t fscache_n_allocs_ok;
 extern atomic_t fscache_n_allocs_wait;
 extern atomic_t fscache_n_allocs_nobufs;
 extern atomic_t fscache_n_allocs_intr;
+extern atomic_t fscache_n_allocs_object_dead;
 extern atomic_t fscache_n_alloc_ops;
 extern atomic_t fscache_n_alloc_op_waits;
 
@@ -166,6 +167,7 @@ extern atomic_t fscache_n_retrievals_nodata;
 extern atomic_t fscache_n_retrievals_nobufs;
 extern atomic_t fscache_n_retrievals_intr;
 extern atomic_t fscache_n_retrievals_nomem;
+extern atomic_t fscache_n_retrievals_object_dead;
 extern atomic_t fscache_n_retrieval_ops;
 extern atomic_t fscache_n_retrieval_op_waits;
 
@@ -249,9 +251,12 @@ static inline void fscache_stat_d(atomic_t *stat)
         atomic_dec(stat);
 }
 
+#define __fscache_stat(stat) (stat)
+
 extern const struct file_operations fscache_stats_fops;
 #else
 
+#define __fscache_stat(stat) (NULL)
 #define fscache_stat(stat) do {} while (0)
 #endif
 
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 74bc562a2cbc..c85c9f582166 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -201,6 +201,7 @@ static void fscache_object_state_machine(struct fscache_object *object)
                 }
                 spin_unlock(&object->lock);
                 fscache_enqueue_dependents(object);
+                fscache_start_operations(object);
                 goto terminal_transit;
 
                 /* handle an abort during initialisation */
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);
diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c
index 9e15289eb5c1..05f77caf4a2d 100644
--- a/fs/fscache/stats.c
+++ b/fs/fscache/stats.c
@@ -39,6 +39,7 @@ atomic_t fscache_n_allocs_ok;
 atomic_t fscache_n_allocs_wait;
 atomic_t fscache_n_allocs_nobufs;
 atomic_t fscache_n_allocs_intr;
+atomic_t fscache_n_allocs_object_dead;
 atomic_t fscache_n_alloc_ops;
 atomic_t fscache_n_alloc_op_waits;
 
@@ -49,6 +50,7 @@ atomic_t fscache_n_retrievals_nodata;
 atomic_t fscache_n_retrievals_nobufs;
 atomic_t fscache_n_retrievals_intr;
 atomic_t fscache_n_retrievals_nomem;
+atomic_t fscache_n_retrievals_object_dead;
 atomic_t fscache_n_retrieval_ops;
 atomic_t fscache_n_retrieval_op_waits;
 
@@ -188,9 +190,10 @@ static int fscache_stats_show(struct seq_file *m, void *v)
                    atomic_read(&fscache_n_allocs_wait),
                    atomic_read(&fscache_n_allocs_nobufs),
                    atomic_read(&fscache_n_allocs_intr));
-        seq_printf(m, "Allocs : ops=%u owt=%u\n",
+        seq_printf(m, "Allocs : ops=%u owt=%u abt=%u\n",
                    atomic_read(&fscache_n_alloc_ops),
-                   atomic_read(&fscache_n_alloc_op_waits));
+                   atomic_read(&fscache_n_alloc_op_waits),
+                   atomic_read(&fscache_n_allocs_object_dead));
 
         seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
                    " int=%u oom=%u\n",
@@ -201,9 +204,10 @@ static int fscache_stats_show(struct seq_file *m, void *v)
                    atomic_read(&fscache_n_retrievals_nobufs),
                    atomic_read(&fscache_n_retrievals_intr),
                    atomic_read(&fscache_n_retrievals_nomem));
-        seq_printf(m, "Retrvls: ops=%u owt=%u\n",
+        seq_printf(m, "Retrvls: ops=%u owt=%u abt=%u\n",
                    atomic_read(&fscache_n_retrieval_ops),
-                   atomic_read(&fscache_n_retrieval_op_waits));
+                   atomic_read(&fscache_n_retrieval_op_waits),
+                   atomic_read(&fscache_n_retrievals_object_dead));
 
         seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
                    atomic_read(&fscache_n_stores),
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 4750d5fb419f..907bb56c5888 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -404,6 +404,10 @@ extern const char *fscache_object_states[];
          (obj)->state >= FSCACHE_OBJECT_AVAILABLE &&          \
          (obj)->state < FSCACHE_OBJECT_DYING)
 
+#define fscache_object_is_dead(obj)                             \
+        (test_bit(FSCACHE_IOERROR, &(obj)->cache->flags) &&     \
+         (obj)->state >= FSCACHE_OBJECT_DYING)
+
 extern const struct slow_work_ops fscache_object_slow_work_ops;
 
 /**