Commit 5404bc7a authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
Browse files

[PATCH] Allow file systems to differentiate between data and meta reads 



We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent da20a20f

block/ll_rw_blk.c

+2 −0
Original line number Diff line number Diff line
@@ -2884,6 +2884,8 @@ static void init_request_from_bio(struct request *req, struct bio *bio) 


	if (bio_sync(bio))

		req->cmd_flags |= REQ_RW_SYNC;

	if (bio_rw_meta(bio))

		req->cmd_flags |= REQ_RW_META;



	req->errors = 0;

	req->hard_sector = req->sector = bio->bi_sector;

include/linux/bio.h

+2 −0
Original line number Diff line number Diff line
@@ -148,6 +148,7 @@ struct bio { 
#define BIO_RW_BARRIER	2

#define BIO_RW_FAILFAST	3

#define BIO_RW_SYNC	4

#define BIO_RW_META	5



/*

 * upper 16 bits of bi_rw define the io priority of this bio
@@ -178,6 +179,7 @@ struct bio { 
#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))

#define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))



/*

 * will die

include/linux/blkdev.h

+3 −0
Original line number Diff line number Diff line
@@ -180,6 +180,7 @@ enum rq_flag_bits { 
	__REQ_ORDERED_COLOR,	/* is before or after barrier */

	__REQ_RW_SYNC,		/* request is sync (O_DIRECT) */

	__REQ_ALLOCED,		/* request came from our alloc pool */

	__REQ_RW_META,		/* metadata io request */

	__REQ_NR_BITS,		/* stops here */

};
@@ -200,6 +201,7 @@ enum rq_flag_bits { 
#define REQ_ORDERED_COLOR	(1 << __REQ_ORDERED_COLOR)

#define REQ_RW_SYNC	(1 << __REQ_RW_SYNC)

#define REQ_ALLOCED	(1 << __REQ_ALLOCED)

#define REQ_RW_META	(1 << __REQ_RW_META)



#define BLK_MAX_CDB	16
@@ -543,6 +545,7 @@ enum { 
 * We regard a request as sync, if it's a READ or a SYNC write.

 */

#define rq_is_sync(rq)		(rq_data_dir((rq)) == READ || (rq)->cmd_flags & REQ_RW_SYNC)

#define rq_is_meta(rq)		((rq)->cmd_flags & REQ_RW_META)



static inline int blk_queue_full(struct request_queue *q, int rw)

{

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ extern int dir_notify_enable; 
#define READA 2		/* read-ahead  - don't block if no resources */

#define SWRITE 3	/* for ll_rw_block() - wait for buffer lock */

#define READ_SYNC	(READ | (1 << BIO_RW_SYNC))

#define READ_META	(READ | (1 << BIO_RW_META))

#define WRITE_SYNC	(WRITE | (1 << BIO_RW_SYNC))

#define WRITE_BARRIER	((1 << BIO_RW) | (1 << BIO_RW_BARRIER))