Commit f3876930 authored by's avatar Committed by Jens Axboe
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block: add a non-queueable flush flag

flush request isn't queueable in some drives. Add a flag to let driver
notify block layer about this. We can optimize flush performance with the

Stable: 2.6.39 only

Signed-off-by: default avatarShaohua Li <>
Acked-by: default avatarTejun Heo <>
Signed-off-by: default avatarJens Axboe <>
parent 490b94be
......@@ -790,6 +790,12 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush)
void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
q->flush_not_queueable = !queueable;
static int __init blk_settings_init(void)
blk_max_low_pfn = max_low_pfn - 1;
......@@ -364,6 +364,7 @@ struct request_queue
* for flush operations
unsigned int flush_flags;
unsigned int flush_not_queueable:1;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
unsigned long flush_pending_since;
......@@ -843,6 +844,7 @@ extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
......@@ -1111,6 +1113,11 @@ static inline unsigned int block_size(struct block_device *bdev)
return bdev->bd_block_size;
static inline bool queue_flush_queueable(struct request_queue *q)
return !q->flush_not_queueable;
typedef struct {struct page *v;} Sector;
unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
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