1 files changed, 71 insertions, 35 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4d18ff34670a..16a902f099ac 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -108,11 +108,17 @@ struct request {
 
         /*
          * Three pointers are available for the IO schedulers, if they need
-         * more they have to dynamically allocate it.
+         * more they have to dynamically allocate it.  Flush requests are
+         * never put on the IO scheduler. So let the flush fields share
+         * space with the three elevator_private pointers.
          */
-        void *elevator_private;
-        void *elevator_private2;
-        void *elevator_private3;
+        union {
+                void *elevator_private[3];
+                struct {
+                        unsigned int            seq;
+                        struct list_head        list;
+                } flush;
+        };
 
         struct gendisk *rq_disk;
         struct hd_struct *part;
@@ -190,7 +196,6 @@ typedef void (request_fn_proc) (struct request_queue *q);
 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
-typedef void (unplug_fn) (struct request_queue *);
 
 struct bio_vec;
 struct bvec_merge_data {
@@ -273,7 +278,6 @@ struct request_queue
         make_request_fn         *make_request_fn;
         prep_rq_fn              *prep_rq_fn;
         unprep_rq_fn            *unprep_rq_fn;
-        unplug_fn               *unplug_fn;
         merge_bvec_fn           *merge_bvec_fn;
         softirq_done_fn         *softirq_done_fn;
         rq_timed_out_fn         *rq_timed_out_fn;
@@ -287,12 +291,9 @@ struct request_queue
         struct request          *boundary_rq;
 
         /*
-         * Auto-unplugging state
+         * Delayed queue handling
          */
-        struct timer_list       unplug_timer;
-        int                     unplug_thresh;  /* After this many requests */
-        unsigned long           unplug_delay;   /* After this many jiffies */
-        struct work_struct      unplug_work;
+        struct delayed_work     delay_work;
 
         struct backing_dev_info backing_dev_info;
 
@@ -363,11 +364,12 @@ struct request_queue
          * for flush operations
          */
         unsigned int            flush_flags;
-        unsigned int            flush_seq;
-        int                     flush_err;
+        unsigned int            flush_pending_idx:1;
+        unsigned int            flush_running_idx:1;
+        unsigned long           flush_pending_since;
+        struct list_head        flush_queue[2];
+        struct list_head        flush_data_in_flight;
         struct request          flush_rq;
-        struct request          *orig_flush_rq;
-        struct list_head        pending_flushes;
 
         struct mutex            sysfs_lock;
 
@@ -387,14 +389,13 @@ struct request_queue
 #define QUEUE_FLAG_ASYNCFULL    4       /* write queue has been filled */
 #define QUEUE_FLAG_DEAD         5       /* queue being torn down */
 #define QUEUE_FLAG_REENTER      6       /* Re-entrancy avoidance */
-#define QUEUE_FLAG_PLUGGED      7       /* queue is plugged */
-#define QUEUE_FLAG_ELVSWITCH    8       /* don't use elevator, just do FIFO */
-#define QUEUE_FLAG_BIDI         9       /* queue supports bidi requests */
-#define QUEUE_FLAG_NOMERGES    10       /* disable merge attempts */
-#define QUEUE_FLAG_SAME_COMP   11       /* force complete on same CPU */
-#define QUEUE_FLAG_FAIL_IO     12       /* fake timeout */
-#define QUEUE_FLAG_STACKABLE   13       /* supports request stacking */
-#define QUEUE_FLAG_NONROT      14       /* non-rotational device (SSD) */
+#define QUEUE_FLAG_ELVSWITCH    7       /* don't use elevator, just do FIFO */
+#define QUEUE_FLAG_BIDI         8       /* queue supports bidi requests */
+#define QUEUE_FLAG_NOMERGES     9       /* disable merge attempts */
+#define QUEUE_FLAG_SAME_COMP   10       /* force complete on same CPU */
+#define QUEUE_FLAG_FAIL_IO     11       /* fake timeout */
+#define QUEUE_FLAG_STACKABLE   12       /* supports request stacking */
+#define QUEUE_FLAG_NONROT      13       /* non-rotational device (SSD) */
 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 #define QUEUE_FLAG_IO_STAT     15       /* do IO stats */
 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
@@ -472,7 +473,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
         __clear_bit(flag, &q->queue_flags);
 }
 
-#define blk_queue_plugged(q)    test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 #define blk_queue_tagged(q)     test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 #define blk_queue_stopped(q)    test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
@@ -667,9 +667,7 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 extern void blk_rq_unprep_clone(struct request *rq);
 extern int blk_insert_cloned_request(struct request_queue *q,
                                      struct request *rq);
-extern void blk_plug_device(struct request_queue *);
-extern void blk_plug_device_unlocked(struct request_queue *);
-extern int blk_remove_plug(struct request_queue *);
+extern void blk_delay_queue(struct request_queue *, unsigned long);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
                           unsigned int, void __user *);
@@ -699,7 +697,7 @@ extern void blk_start_queue(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
 extern void __blk_stop_queue(struct request_queue *q);
-extern void __blk_run_queue(struct request_queue *);
+extern void __blk_run_queue(struct request_queue *q, bool force_kblockd);
 extern void blk_run_queue(struct request_queue *);
 extern int blk_rq_map_user(struct request_queue *, struct request *,
                            struct rq_map_data *, void __user *, unsigned long,
@@ -713,7 +711,6 @@ extern int blk_execute_rq(struct request_queue *, struct gendisk *,
                           struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
                                   struct request *, int, rq_end_io_fn *);
-extern void blk_unplug(struct request_queue *q);
 
 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 {
@@ -850,7 +847,6 @@ extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bd
 
 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 extern void blk_dump_rq_flags(struct request *, char *);
-extern void generic_unplug_device(struct request_queue *);
 extern long nr_blockdev_pages(void);
 
 int blk_get_queue(struct request_queue *);
@@ -858,6 +854,31 @@ struct request_queue *blk_alloc_queue(gfp_t);
 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 extern void blk_put_queue(struct request_queue *);
 
+struct blk_plug {
+        unsigned long magic;
+        struct list_head list;
+        unsigned int should_sort;
+};
+
+extern void blk_start_plug(struct blk_plug *);
+extern void blk_finish_plug(struct blk_plug *);
+extern void __blk_flush_plug(struct task_struct *, struct blk_plug *);
+
+static inline void blk_flush_plug(struct task_struct *tsk)
+{
+        struct blk_plug *plug = tsk->plug;
+
+        if (unlikely(plug))
+                __blk_flush_plug(tsk, plug);
+}
+
+static inline bool blk_needs_flush_plug(struct task_struct *tsk)
+{
+        struct blk_plug *plug = tsk->plug;
+
+        return plug && !list_empty(&plug->list);
+}
+
 /*
  * tag stuff
  */
@@ -1088,7 +1109,6 @@ static inline void put_dev_sector(Sector p)
 
 struct work_struct;
 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
-int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
 
 #ifdef CONFIG_BLK_CGROUP
 /*
@@ -1136,8 +1156,6 @@ static inline uint64_t rq_io_start_time_ns(struct request *req)
 extern int blk_throtl_init(struct request_queue *q);
 extern void blk_throtl_exit(struct request_queue *q);
 extern int blk_throtl_bio(struct request_queue *q, struct bio **bio);
-extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay);
-extern void throtl_shutdown_timer_wq(struct request_queue *q);
 #else /* CONFIG_BLK_DEV_THROTTLING */
 static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
 {
@@ -1146,8 +1164,6 @@ static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio)
 
 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 static inline int blk_throtl_exit(struct request_queue *q) { return 0; }
-static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {}
-static inline void throtl_shutdown_timer_wq(struct request_queue *q) {}
 #endif /* CONFIG_BLK_DEV_THROTTLING */
 
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
@@ -1281,6 +1297,26 @@ static inline long nr_blockdev_pages(void)
         return 0;
 }
 
+struct blk_plug {
+};
+
+static inline void blk_start_plug(struct blk_plug *plug)
+{
+}
+
+static inline void blk_finish_plug(struct blk_plug *plug)
+{
+}
+
+static inline void blk_flush_plug(struct task_struct *task)
+{
+}
+
+static inline bool blk_needs_flush_plug(struct task_struct *tsk)
+{
+        return false;
+}
+
 #endif /* CONFIG_BLOCK */
 
 #endif