diff options
| author | Jens Axboe <axboe@kernel.dk> | 2017-06-16 11:15:32 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-06-17 13:54:15 -0600 |
| commit | a0311a8e50b6247753801a24a82c08129b073ad8 (patch) | |
| tree | cd92c2b1f3d2484a8d390f81ae8236a1936febad | |
| parent | 8cf10acc243994d6a734f5e22666d1629294292b (diff) | |
block: add support for write hints in a bio
No functional changes in this patch, we just set aside 3 bits
in the bio/request flags, which can be used to hold a WRITE_HINT_*
life time hint.
Ensure that we don't merge requests that have different life time
hints assigned to them.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-merge.c | 16 | ||||
| -rw-r--r-- | include/linux/blk_types.h | 15 |
2 files changed, 31 insertions, 0 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index 3990ae406341..7d299df3b12b 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -693,6 +693,14 @@ static struct request *attempt_merge(struct request_queue *q, return NULL; /* + * Don't allow merge of different streams, or for a stream with + * non-stream IO. + */ + if ((req->cmd_flags & REQ_WRITE_LIFE_MASK) != + (next->cmd_flags & REQ_WRITE_LIFE_MASK)) + return NULL; + + /* * If we are allowed to merge, then append bio list * from next to rq and release next. merge_requests_fn * will have updated segment counts, update sector @@ -811,6 +819,14 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) !blk_write_same_mergeable(rq->bio, bio)) return false; + /* + * Don't allow merge of different streams, or for a stream with + * non-stream IO. + */ + if ((rq->cmd_flags & REQ_WRITE_LIFE_MASK) != + (bio->bi_opf & REQ_WRITE_LIFE_MASK)) + return false; + return true; } diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 61339bc44400..0dd8d569d52f 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -7,6 +7,7 @@ #include <linux/types.h> #include <linux/bvec.h> +#include <linux/fs.h> struct bio_set; struct bio; @@ -201,6 +202,9 @@ enum req_flag_bits { __REQ_PREFLUSH, /* request for cache flush */ __REQ_RAHEAD, /* read ahead, can fail anytime */ __REQ_BACKGROUND, /* background IO */ + __REQ_WRITE_HINT_SHIFT, /* 3 bits for life time hint */ + __REQ_WRITE_HINT_PAD1, + __REQ_WRITE_HINT_PAD2, /* command specific flags for REQ_OP_WRITE_ZEROES: */ __REQ_NOUNMAP, /* do not free blocks when zeroing */ @@ -221,6 +225,12 @@ enum req_flag_bits { #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH) #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND) +#define REQ_WRITE_SHORT (WRITE_LIFE_SHORT << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_MEDIUM (WRITE_LIFE_MEDIUM << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_LONG (WRITE_LIFE_LONG << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_EXTREME (WRITE_LIFE_EXTREME << __REQ_WRITE_HINT_SHIFT) + +#define REQ_WRITE_LIFE_MASK (0x7 << __REQ_WRITE_HINT_SHIFT) #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) @@ -312,4 +322,9 @@ struct blk_rq_stat { u64 batch; }; +static inline unsigned int write_hint_to_opf(enum rw_hint hint) +{ + return hint << __REQ_WRITE_HINT_SHIFT; +} + #endif /* __LINUX_BLK_TYPES_H */ |