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authorJosef Bacik <jbacik@fb.com>2018-07-03 11:14:53 -0400
committerJens Axboe <axboe@kernel.dk>2018-07-09 09:07:54 -0600
commit0d1e0c7cd5909d6c6aa0957179318e13fcca971a (patch)
tree891b19b5a5c21e0a9daddcf281892184113265dc /include
parent903d23f0a354f226fa78f1c1c34b60aaf992e812 (diff)
downloadlinux-0d1e0c7cd5909d6c6aa0957179318e13fcca971a.tar.gz
blk: introduce REQ_SWAP
Just like REQ_META, it's important to know the IO coming down is swap
in order to guard against potential IO priority inversion issues with
cgroups.  Add REQ_SWAP and use it for all swap IO, and add it to our
bio_issue_as_root_blkg helper.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
-rw-r--r--include/linux/blk-cgroup.h2
-rw-r--r--include/linux/blk_types.h3
2 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index b41292726c0f..a8f9ba8f33a4 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -254,7 +254,7 @@ static inline struct blkcg *bio_blkcg(struct bio *bio)
  */
 static inline bool bio_issue_as_root_blkg(struct bio *bio)
 {
-	return (bio->bi_opf & REQ_META);
+	return (bio->bi_opf & (REQ_META | REQ_SWAP)) != 0;
 }
 
 /**
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 3364d42ebe08..0ffc34c5cc83 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -329,7 +329,7 @@ enum req_flag_bits {
 
 	/* for driver use */
 	__REQ_DRV,
-
+	__REQ_SWAP,		/* swapping request. */
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -351,6 +351,7 @@ enum req_flag_bits {
 #define REQ_NOUNMAP		(1ULL << __REQ_NOUNMAP)
 
 #define REQ_DRV			(1ULL << __REQ_DRV)
+#define REQ_SWAP		(1ULL << __REQ_SWAP)
 
 #define REQ_FAILFAST_MASK \
 	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)