[PATCH] REQ-flags to/from BIO-flags bugfix

Boaz Harrosh
2007-12-12T11:03:56Z

- BIO flags bio->bi_rw and REQ flags req->cmd_flags no longer match.
Remove comments and do a proper translation between the 2 systems.

(Please look in ll_rw_blk.c/blk_rq_bio_prep() below if we need more flags)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
---
block/ll_rw_blk.c | 23 +++++++++++++++++------
include/linux/blktrace_api.h | 8 +++++++-
2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 8b91994..c6a84bb 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1990,10 +1990,6 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
if (!rq)
return NULL;

- /*
- * 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;

if (priv) {
@@ -3772,8 +3768,23 @@ EXPORT_SYMBOL(end_request);
static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
{
- /* first two bits are identical in rq->cmd_flags and bio->bi_rw */
- rq->cmd_flags |= (bio->bi_rw & 3);
+ if (bio_data_dir(bio))
+ rq->cmd_flags |= REQ_RW;
+ else
+ rq->cmd_flags &= ~REQ_RW;
+
+ if (bio->bi_rw & (1<<BIO_RW_SYNC))
+ rq->cmd_flags |= REQ_RW_SYNC;
+ else
+ rq->cmd_flags &= ~REQ_RW_SYNC;
+ /* FIXME: what about other flags, should we sync these too? */
+ /*
+ BIO_RW_AHEAD ==> ??
+ BIO_RW_BARRIER ==> REQ_SOFTBARRIER/REQ_HARDBARRIER
+ BIO_RW_FAILFAST ==> REQ_FAILFAST
+ BIO_RW_SYNC ==> REQ_RW_SYNC
+ BIO_RW_META ==> REQ_RW_META
+ */

rq->nr_phys_segments = bio_phys_segments(q, bio);
rq->nr_hw_segments = bio_hw_segments(q, bio);
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 7e11d23..9e7ce65 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -165,7 +165,13 @@ static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
- int rw = rq->cmd_flags & 0x03;
+ /* blktrace.c prints them according to bio flags */
+ int rw = (((rq_rw_dir(rq) == WRITE) << BIO_RW) |
+ (((rq->cmd_flags & (REQ_SOFTBARRIER|REQ_HARDBARRIER)) != 0) <<
+ BIO_RW_BARRIER) |
+ (((rq->cmd_flags & REQ_FAILFAST) != 0) << BIO_RW_FAILFAST) |
+ (((rq->cmd_flags & REQ_RW_SYNC) != 0) << BIO_RW_SYNC) |
+ (((rq->cmd_flags & REQ_RW_META) != 0) << BIO_RW_META));

if (likely(!bt))
return;
--
1.5.3.3