Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache

* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache: (31 commits)
  FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS=n
  SLOW_WORK: Fix GFS2 to #include <linux/module.h> before using THIS_MODULE
  SLOW_WORK: Fix CIFS to pass THIS_MODULE to slow_work_register_user()
  CacheFiles: Don't log lookup/create failing with ENOBUFS
  CacheFiles: Catch an overly long wait for an old active object
  CacheFiles: Better showing of debugging information in active object problems
  CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happy
  CacheFiles: Handle truncate unlocking the page we're reading
  CacheFiles: Don't write a full page if there's only a partial page to cache
  FS-Cache: Actually requeue an object when requested
  FS-Cache: Start processing an object's operations on that object's death
  FS-Cache: Make sure FSCACHE_COOKIE_LOOKING_UP cleared on lookup failure
  FS-Cache: Add a retirement stat counter
  FS-Cache: Handle pages pending storage that get evicted under OOM conditions
  FS-Cache: Handle read request vs lookup, creation or other cache failure
  FS-Cache: Don't delete pending pages from the page-store tracking tree
  FS-Cache: Fix lock misorder in fscache_write_op()
  FS-Cache: The object-available state can't rely on the cookie to be available
  FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phase
  FS-Cache: Use radix tree preload correctly in tracking of pages to be stored
  ...

1 files changed, 38 insertions, 2 deletions

diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 84d3532dd3ea..7be0c6fbe880 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -91,6 +91,8 @@ struct fscache_operation {
 #define FSCACHE_OP_WAITING	4	/* cleared when op is woken */
 #define FSCACHE_OP_EXCLUSIVE	5	/* exclusive op, other ops must wait */
 #define FSCACHE_OP_DEAD		6	/* op is now dead */
+#define FSCACHE_OP_DEC_READ_CNT	7	/* decrement object->n_reads on destruction */
+#define FSCACHE_OP_KEEP_FLAGS	0xc0	/* flags to keep when repurposing an op */
 
 	atomic_t		usage;
 	unsigned		debug_id;	/* debugging ID */
@@ -102,6 +104,16 @@ struct fscache_operation {
 
 	/* operation releaser */
 	fscache_operation_release_t release;
+
+#ifdef CONFIG_SLOW_WORK_PROC
+	const char *name;		/* operation name */
+	const char *state;		/* operation state */
+#define fscache_set_op_name(OP, N)	do { (OP)->name  = (N); } while(0)
+#define fscache_set_op_state(OP, S)	do { (OP)->state = (S); } while(0)
+#else
+#define fscache_set_op_name(OP, N)	do { } while(0)
+#define fscache_set_op_state(OP, S)	do { } while(0)
+#endif
 };
 
 extern atomic_t fscache_op_debug_id;
@@ -125,6 +137,7 @@ static inline void fscache_operation_init(struct fscache_operation *op,
 	op->debug_id = atomic_inc_return(&fscache_op_debug_id);
 	op->release = release;
 	INIT_LIST_HEAD(&op->pend_link);
+	fscache_set_op_state(op, "Init");
 }
 
 /**
@@ -221,8 +234,10 @@ struct fscache_cache_ops {
 	struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
 					       struct fscache_cookie *cookie);
 
-	/* look up the object for a cookie */
-	void (*lookup_object)(struct fscache_object *object);
+	/* look up the object for a cookie
+	 * - return -ETIMEDOUT to be requeued
+	 */
+	int (*lookup_object)(struct fscache_object *object);
 
 	/* finished looking up */
 	void (*lookup_complete)(struct fscache_object *object);
@@ -297,12 +312,14 @@ struct fscache_cookie {
 	atomic_t			usage;		/* number of users of this cookie */
 	atomic_t			n_children;	/* number of children of this cookie */
 	spinlock_t			lock;
+	spinlock_t			stores_lock;	/* lock on page store tree */
 	struct hlist_head		backing_objects; /* object(s) backing this file/index */
 	const struct fscache_cookie_def	*def;		/* definition */
 	struct fscache_cookie		*parent;	/* parent of this entry */
 	void				*netfs_data;	/* back pointer to netfs */
 	struct radix_tree_root		stores;		/* pages to be stored on this cookie */
 #define FSCACHE_COOKIE_PENDING_TAG	0		/* pages tag: pending write to cache */
+#define FSCACHE_COOKIE_STORING_TAG	1		/* pages tag: writing to cache */
 
 	unsigned long			flags;
 #define FSCACHE_COOKIE_LOOKING_UP	0	/* T if non-index cookie being looked up still */
@@ -337,6 +354,7 @@ struct fscache_object {
 		FSCACHE_OBJECT_RECYCLING,	/* retiring object */
 		FSCACHE_OBJECT_WITHDRAWING,	/* withdrawing object */
 		FSCACHE_OBJECT_DEAD,		/* object is now dead */
+		FSCACHE_OBJECT__NSTATES
 	} state;
 
 	int			debug_id;	/* debugging ID */
@@ -345,6 +363,7 @@ struct fscache_object {
 	int			n_obj_ops;	/* number of object ops outstanding on object */
 	int			n_in_progress;	/* number of ops in progress */
 	int			n_exclusive;	/* number of exclusive ops queued */
+	atomic_t		n_reads;	/* number of read ops in progress */
 	spinlock_t		lock;		/* state and operations lock */
 
 	unsigned long		lookup_jif;	/* time at which lookup started */
@@ -358,6 +377,7 @@ struct fscache_object {
 #define FSCACHE_OBJECT_EV_RELEASE	4	/* T if netfs requested object release */
 #define FSCACHE_OBJECT_EV_RETIRE	5	/* T if netfs requested object retirement */
 #define FSCACHE_OBJECT_EV_WITHDRAW	6	/* T if cache requested object withdrawal */
+#define FSCACHE_OBJECT_EVENTS_MASK	0x7f	/* mask of all events*/
 
 	unsigned long		flags;
 #define FSCACHE_OBJECT_LOCK		0	/* T if object is busy being processed */
@@ -373,7 +393,11 @@ struct fscache_object {
 	struct list_head	dependents;	/* FIFO of dependent objects */
 	struct list_head	dep_link;	/* link in parent's dependents list */
 	struct list_head	pending_ops;	/* unstarted operations on this object */
+#ifdef CONFIG_FSCACHE_OBJECT_LIST
+	struct rb_node		objlist_link;	/* link in global object list */
+#endif
 	pgoff_t			store_limit;	/* current storage limit */
+	loff_t			store_limit_l;	/* current storage limit */
 };
 
 extern const char *fscache_object_states[];
@@ -383,6 +407,10 @@ 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;
 
 /**
@@ -414,6 +442,7 @@ void fscache_object_init(struct fscache_object *object,
 	object->events = object->event_mask = 0;
 	object->flags = 0;
 	object->store_limit = 0;
+	object->store_limit_l = 0;
 	object->cache = cache;
 	object->cookie = cookie;
 	object->parent = NULL;
@@ -422,6 +451,12 @@ void fscache_object_init(struct fscache_object *object,
 extern void fscache_object_lookup_negative(struct fscache_object *object);
 extern void fscache_obtained_object(struct fscache_object *object);
 
+#ifdef CONFIG_FSCACHE_OBJECT_LIST
+extern void fscache_object_destroy(struct fscache_object *object);
+#else
+#define fscache_object_destroy(object) do {} while(0)
+#endif
+
 /**
  * fscache_object_destroyed - Note destruction of an object in a cache
  * @cache: The cache from which the object came
@@ -460,6 +495,7 @@ static inline void fscache_object_lookup_error(struct fscache_object *object)
 static inline
 void fscache_set_store_limit(struct fscache_object *object, loff_t i_size)
 {
+	object->store_limit_l = i_size;
 	object->store_limit = i_size >> PAGE_SHIFT;
 	if (i_size & ~PAGE_MASK)
 		object->store_limit++;