This adds a new request flag, REQ_BG, that callers can use to tell
the block layer that this is background (non-urgent) IO.
No functional changes in this patch.
Signed-off-by: Jens Axboe <ax...@fb.com>
---
include/linux/blk_types.h | 4 +++-
include/linux/fs.h | 4 ++++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 86a38ea1823f..223012451c7a 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -161,6 +161,7 @@ enum rq_flag_bits {
__REQ_INTEGRITY, /* I/O includes block integrity payload */
__REQ_FUA, /* forced unit access */
__REQ_FLUSH, /* request for cache flush */
+ __REQ_BG, /* background activity */
/* bio only flags */
__REQ_RAHEAD, /* read ahead, can fail anytime */
@@ -208,7 +209,7 @@ enum rq_flag_bits {
#define REQ_COMMON_MASK \
(REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \
- REQ_SECURE | REQ_INTEGRITY)
+ REQ_SECURE | REQ_INTEGRITY | REQ_BG)
#define REQ_CLONE_MASK REQ_COMMON_MASK
#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME)
@@ -235,6 +236,7 @@ enum rq_flag_bits {
#define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
#define REQ_FLUSH (1ULL << __REQ_FLUSH)
#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
+#define REQ_BG (1ULL << __REQ_BG)
#define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
#define REQ_SECURE (1ULL << __REQ_SECURE)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 70e61b58baaf..bb8f951cc619 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -192,6 +192,9 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int
uptodate);
* WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
* by a cache flush and data is guaranteed to be on
* non-volatile media on completion.
+ * WRITE_BG Background write. This is for background activity like
+ * the periodic flush and background threshold writeback
+ *
*
*/
#define RW_MASK REQ_WRITE
@@ -207,6 +210,7 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int
uptodate);
#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE |
REQ_FLUSH | REQ_FUA)
+#define WRITE_BG (WRITE | REQ_NOIDLE | REQ_BG)
/*
* Attribute flags. These should be or-ed together to figure out what
--
2.8.0.rc4.6.g7e4ba36
