---

yaml
---
r: 168834
b: refs/heads/master
c: 60d543c
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d461d26dde901b0523c46b0317e7fccf574a3933
+refs/heads/master: 60d543ca724be155c2b6166e36a00c80b21bd810

trunk/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

trunk/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
 

trunk/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 */

trunk/fs/fscache/page.c

@@ -313,6 +313,43 @@ static int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
 	return 0;
 }
 
+/*
+ * 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:
@@ -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);

trunk/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),

trunk/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;
 
 /**