block: Clean up special command handling logic
Remove special-casing of non-rw fs style requests (discard). The nomerge
flags are consolidated in blk_types.h, and rq_mergeable() and
bio_mergeable() have been modified to use them.
bio_is_rw() is used in place of bio_has_data() a few places. This is
done to to distinguish true reads and writes from other fs type requests
that carry a payload (e.g. write same).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-core.c b/block/blk-core.c
index 2d739ca..5cc2929 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1657,8 +1657,8 @@
goto end_io;
}
- if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
- nr_sectors > queue_max_hw_sectors(q))) {
+ if (likely(bio_is_rw(bio) &&
+ nr_sectors > queue_max_hw_sectors(q))) {
printk(KERN_ERR "bio too big device %s (%u > %u)\n",
bdevname(bio->bi_bdev, b),
bio_sectors(bio),
@@ -1699,8 +1699,7 @@
if ((bio->bi_rw & REQ_DISCARD) &&
(!blk_queue_discard(q) ||
- ((bio->bi_rw & REQ_SECURE) &&
- !blk_queue_secdiscard(q)))) {
+ ((bio->bi_rw & REQ_SECURE) && !blk_queue_secdiscard(q)))) {
err = -EOPNOTSUPP;
goto end_io;
}
@@ -1818,7 +1817,7 @@
* If it's a regular read/write or a barrier with data attached,
* go through the normal accounting stuff before submission.
*/
- if (bio_has_data(bio) && !(rw & REQ_DISCARD)) {
+ if (bio_has_data(bio)) {
if (rw & WRITE) {
count_vm_events(PGPGOUT, count);
} else {
@@ -1864,7 +1863,7 @@
*/
int blk_rq_check_limits(struct request_queue *q, struct request *rq)
{
- if (rq->cmd_flags & REQ_DISCARD)
+ if (!rq_mergeable(rq))
return 0;
if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
@@ -2338,7 +2337,7 @@
req->buffer = bio_data(req->bio);
/* update sector only for requests with clear definition of sector */
- if (req->cmd_type == REQ_TYPE_FS || (req->cmd_flags & REQ_DISCARD))
+ if (req->cmd_type == REQ_TYPE_FS)
req->__sector += total_bytes >> 9;
/* mixed attributes always follow the first bio */
diff --git a/block/blk-merge.c b/block/blk-merge.c
index e76279e..86710ca 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -418,18 +418,6 @@
return 0;
/*
- * Don't merge file system requests and discard requests
- */
- if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))
- return 0;
-
- /*
- * Don't merge discard requests and secure discard requests
- */
- if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))
- return 0;
-
- /*
* not contiguous
*/
if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
@@ -521,15 +509,7 @@
bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
{
- if (!rq_mergeable(rq))
- return false;
-
- /* don't merge file system requests and discard requests */
- if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
- return false;
-
- /* don't merge discard requests and secure discard requests */
- if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+ if (!rq_mergeable(rq) || !bio_mergeable(bio))
return false;
/* different data direction or already started, don't merge */
diff --git a/block/blk.h b/block/blk.h
index 2a0ea32..ca51543 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -171,14 +171,13 @@
*
* a) it's attached to a gendisk, and
* b) the queue had IO stats enabled when this request was started, and
- * c) it's a file system request or a discard request
+ * c) it's a file system request
*/
static inline int blk_do_io_stat(struct request *rq)
{
return rq->rq_disk &&
(rq->cmd_flags & REQ_IO_STAT) &&
- (rq->cmd_type == REQ_TYPE_FS ||
- (rq->cmd_flags & REQ_DISCARD));
+ (rq->cmd_type == REQ_TYPE_FS);
}
/*
diff --git a/block/elevator.c b/block/elevator.c
index 6a55d41..9b1d42b 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -562,8 +562,7 @@
if (rq->cmd_flags & REQ_SOFTBARRIER) {
/* barriers are scheduling boundary, update end_sector */
- if (rq->cmd_type == REQ_TYPE_FS ||
- (rq->cmd_flags & REQ_DISCARD)) {
+ if (rq->cmd_type == REQ_TYPE_FS) {
q->end_sector = rq_end_sector(rq);
q->boundary_rq = rq;
}
@@ -605,8 +604,7 @@
if (elv_attempt_insert_merge(q, rq))
break;
case ELEVATOR_INSERT_SORT:
- BUG_ON(rq->cmd_type != REQ_TYPE_FS &&
- !(rq->cmd_flags & REQ_DISCARD));
+ BUG_ON(rq->cmd_type != REQ_TYPE_FS);
rq->cmd_flags |= REQ_SORTED;
q->nr_sorted++;
if (rq_mergeable(rq)) {
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 52b9cbc..e54305c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -386,9 +386,28 @@
/*
* Check whether this bio carries any data or not. A NULL bio is allowed.
*/
-static inline int bio_has_data(struct bio *bio)
+static inline bool bio_has_data(struct bio *bio)
{
- return bio && bio->bi_io_vec != NULL;
+ if (bio && bio->bi_vcnt)
+ return true;
+
+ return false;
+}
+
+static inline bool bio_is_rw(struct bio *bio)
+{
+ if (!bio_has_data(bio))
+ return false;
+
+ return true;
+}
+
+static inline bool bio_mergeable(struct bio *bio)
+{
+ if (bio->bi_rw & REQ_NOMERGE_FLAGS)
+ return false;
+
+ return true;
}
/*
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 3eefbb2..1b22966 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -194,6 +194,10 @@
REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
#define REQ_CLONE_MASK REQ_COMMON_MASK
+/* This mask is used for both bio and request merge checking */
+#define REQ_NOMERGE_FLAGS \
+ (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
+
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
#define REQ_THROTTLED (1 << __REQ_THROTTLED)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4a2ab7c..3a6fea7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -540,8 +540,7 @@
#define blk_account_rq(rq) \
(((rq)->cmd_flags & REQ_STARTED) && \
- ((rq)->cmd_type == REQ_TYPE_FS || \
- ((rq)->cmd_flags & REQ_DISCARD)))
+ ((rq)->cmd_type == REQ_TYPE_FS))
#define blk_pm_request(rq) \
((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
@@ -595,17 +594,16 @@
rl->flags &= ~flag;
}
+static inline bool rq_mergeable(struct request *rq)
+{
+ if (rq->cmd_type != REQ_TYPE_FS)
+ return false;
-/*
- * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
- * it already be started by driver.
- */
-#define RQ_NOMERGE_FLAGS \
- (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_DISCARD)
-#define rq_mergeable(rq) \
- (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
- (((rq)->cmd_flags & REQ_DISCARD) || \
- (rq)->cmd_type == REQ_TYPE_FS))
+ if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
+ return false;
+
+ return true;
+}
/*
* q->prep_rq_fn return values
