提交 d628eaef 编写于 作者: D David Woodhouse 提交者: Jens Axboe

Fix up comments about matching flags between bio and rq

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
上级 36144077
...@@ -624,10 +624,6 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask) ...@@ -624,10 +624,6 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
blk_rq_init(q, rq); blk_rq_init(q, rq);
/*
* first three bits are identical in rq->cmd_flags and bio->bi_rw,
* see bio.h and blkdev.h
*/
rq->cmd_flags = rw | REQ_ALLOCED; rq->cmd_flags = rw | REQ_ALLOCED;
if (priv) { if (priv) {
...@@ -2012,7 +2008,8 @@ EXPORT_SYMBOL_GPL(blk_end_request_callback); ...@@ -2012,7 +2008,8 @@ EXPORT_SYMBOL_GPL(blk_end_request_callback);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq, void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio) struct bio *bio)
{ {
/* first two bits are identical in rq->cmd_flags and bio->bi_rw */ /* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
rq->cmd_flags |= (bio->bi_rw & 3); rq->cmd_flags |= (bio->bi_rw & 3);
rq->nr_phys_segments = bio_phys_segments(q, bio); rq->nr_phys_segments = bio_phys_segments(q, bio);
......
...@@ -150,8 +150,8 @@ struct bio { ...@@ -150,8 +150,8 @@ struct bio {
* bit 3 -- fail fast, don't want low level driver retries * bit 3 -- fail fast, don't want low level driver retries
* bit 4 -- synchronous I/O hint: the block layer will unplug immediately * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
*/ */
#define BIO_RW 0 #define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
#define BIO_RW_AHEAD 1 #define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
#define BIO_RW_BARRIER 2 #define BIO_RW_BARRIER 2
#define BIO_RW_FAILFAST 3 #define BIO_RW_FAILFAST 3
#define BIO_RW_SYNC 4 #define BIO_RW_SYNC 4
......
...@@ -84,7 +84,7 @@ enum { ...@@ -84,7 +84,7 @@ enum {
}; };
/* /*
* request type modified bits. first three bits match BIO_RW* bits, important * request type modified bits. first two bits match BIO_RW* bits, important
*/ */
enum rq_flag_bits { enum rq_flag_bits {
__REQ_RW, /* not set, read. set, write */ __REQ_RW, /* not set, read. set, write */
......
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