[PATCH] disk barriers: core

IDE disk barrier core.


Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 31 insertions, 2 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index b90e06c1764483..2585402c2b8b15 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -121,6 +121,7 @@ struct bio {
 #define BIO_CLONED	4	/* doesn't own data */
 #define BIO_BOUNCED	5	/* bio is a bounce bio */
 #define BIO_USER_MAPPED 6	/* contains user pages */
+#define BIO_EOPNOTSUPP	7	/* not supported */
 #define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
 
 /*
@@ -160,6 +161,8 @@ struct bio {
 #define bio_data(bio)		(page_address(bio_page((bio))) + bio_offset((bio)))
 #define bio_barrier(bio)	((bio)->bi_rw & (1 << BIO_RW_BARRIER))
 #define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
+#define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
+#define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
 
 /*
  * will die
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index eb4d10be7e6003..305dcb9311d901 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -195,6 +195,8 @@ enum rq_flag_bits {
 	__REQ_PM_SUSPEND,	/* suspend request */
 	__REQ_PM_RESUME,	/* resume request */
 	__REQ_PM_SHUTDOWN,	/* shutdown request */
+	__REQ_BAR_PREFLUSH,	/* barrier pre-flush done */
+	__REQ_BAR_POSTFLUSH,	/* barrier post-flush */
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -220,6 +222,8 @@ enum rq_flag_bits {
 #define REQ_PM_SUSPEND	(1 << __REQ_PM_SUSPEND)
 #define REQ_PM_RESUME	(1 << __REQ_PM_RESUME)
 #define REQ_PM_SHUTDOWN	(1 << __REQ_PM_SHUTDOWN)
+#define REQ_BAR_PREFLUSH	(1 << __REQ_BAR_PREFLUSH)
+#define REQ_BAR_POSTFLUSH	(1 << __REQ_BAR_POSTFLUSH)
 
 /*
  * State information carried for REQ_PM_SUSPEND and REQ_PM_RESUME
@@ -248,6 +252,7 @@ typedef void (unplug_fn) (request_queue_t *);
 struct bio_vec;
 typedef int (merge_bvec_fn) (request_queue_t *, struct bio *, struct bio_vec *);
 typedef void (activity_fn) (void *data, int rw);
+typedef int (issue_flush_fn) (request_queue_t *, struct gendisk *, sector_t *);
 
 enum blk_queue_state {
 	Queue_down,
@@ -290,6 +295,7 @@ struct request_queue
 	unplug_fn		*unplug_fn;
 	merge_bvec_fn		*merge_bvec_fn;
 	activity_fn		*activity_fn;
+	issue_flush_fn		*issue_flush_fn;
 
 	/*
 	 * Auto-unplugging state
@@ -373,6 +379,7 @@ struct request_queue
 #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_ORDERED	8	/* supports ordered writes */
 
 #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)
@@ -390,6 +397,10 @@ struct request_queue
 #define blk_pm_request(rq)	\
 	((rq)->flags & (REQ_PM_SUSPEND | REQ_PM_RESUME))
 
+#define blk_barrier_rq(rq)	((rq)->flags & REQ_HARDBARRIER)
+#define blk_barrier_preflush(rq)	((rq)->flags & REQ_BAR_PREFLUSH)
+#define blk_barrier_postflush(rq)	((rq)->flags & REQ_BAR_POSTFLUSH)
+
 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
 
 #define rq_data_dir(rq)		((rq)->flags & 1)
@@ -560,6 +571,14 @@ extern void end_that_request_last(struct request *);
 extern int process_that_request_first(struct request *, unsigned int);
 extern void end_request(struct request *req, int uptodate);
 
+/*
+ * end_that_request_first/chunk() takes an uptodate argument. we account
+ * any value <= as an io error. 0 means -EIO for compatability reasons,
+ * any other < 0 value is the direct error type. An uptodate value of
+ * 1 indicates successful io completion
+ */
+#define end_io_error(uptodate)	(unlikely((uptodate) <= 0))
+
 static inline void blkdev_dequeue_request(struct request *req)
 {
 	BUG_ON(list_empty(&req->queuelist));
@@ -588,6 +607,9 @@ extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
 extern void blk_queue_dma_alignment(request_queue_t *, int);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
+extern void blk_queue_ordered(request_queue_t *, int);
+extern void blk_queue_issue_flush_fn(request_queue_t *, issue_flush_fn *);
+extern int blkdev_scsi_issue_flush_fn(request_queue_t *, struct gendisk *, sector_t *);
 
 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
 extern void blk_dump_rq_flags(struct request *, char *);
@@ -616,6 +638,7 @@ extern long blk_congestion_wait(int rw, long timeout);
 
 extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *);
 extern void blk_rq_prep_restart(struct request *);
+extern int blkdev_issue_flush(struct block_device *, sector_t *);
 
 #define MAX_PHYS_SEGMENTS 128
 #define MAX_HW_SEGMENTS 128
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 6d70bd5393e67e..b94bd82e60990a 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -26,6 +26,7 @@ enum bh_state_bits {
 	BH_Delay,	/* Buffer is not yet allocated on disk */
 	BH_Boundary,	/* Block is followed by a discontiguity */
 	BH_Write_EIO,	/* I/O error on write */
+	BH_Ordered,	/* ordered write */
 
 	BH_PrivateStart,/* not a state bit, but the first bit available
 			 * for private allocation by other entities
@@ -110,7 +111,8 @@ BUFFER_FNS(Async_Read, async_read)
 BUFFER_FNS(Async_Write, async_write)
 BUFFER_FNS(Delay, delay)
 BUFFER_FNS(Boundary, boundary)
-BUFFER_FNS(Write_EIO,write_io_error)
+BUFFER_FNS(Write_EIO, write_io_error)
+BUFFER_FNS(Ordered, ordered)
 
 #define bh_offset(bh)		((unsigned long)(bh)->b_data & ~PAGE_MASK)
 #define touch_buffer(bh)	mark_page_accessed(bh->b_page)
@@ -173,7 +175,7 @@ void FASTCALL(unlock_buffer(struct buffer_head *bh));
 void FASTCALL(__lock_buffer(struct buffer_head *bh));
 void ll_rw_block(int, int, struct buffer_head * bh[]);
 void sync_dirty_buffer(struct buffer_head *bh);
-void submit_bh(int, struct buffer_head *);
+int submit_bh(int, struct buffer_head *);
 void write_boundary_block(struct block_device *bdev,
 			sector_t bblock, unsigned blocksize);
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7e10a252a7d175..d2cf71862d71b7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -88,6 +88,7 @@ extern int leases_enable, dir_notify_enable, lease_break_time;
 #define SPECIAL 4	/* For non-blockdevice requests in request queue */
 #define READ_SYNC	(READ | (1 << BIO_RW_SYNC))
 #define WRITE_SYNC	(WRITE | (1 << BIO_RW_SYNC))
+#define WRITE_BARRIER	((1 << BIO_RW) | (1 << BIO_RW_BARRIER))
 
 #define SEL_IN		1
 #define SEL_OUT		2