[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: Jens Axboe <axboe@suse.de>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index e3980ec..57992ae 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2884,6 +2884,8 @@
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;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 76bdaea..711c321 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -148,6 +148,7 @@
#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 @@
#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
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5d8e288..2c01a90 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -180,6 +180,7 @@
__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 @@
#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 @@
* 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)
{
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9306f63..d68c37a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -80,6 +80,7 @@
#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))
