blk-mq: Allow requests to never expire

Some types of requests may be started that are not gauranteed to ever
complete. This adds a request flag that a driver can use so mark the
request as such.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 445d59231bc4..c294e3e25e37 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -190,6 +190,7 @@ enum rq_flag_bits {
         __REQ_PM,               /* runtime pm request */
         __REQ_HASHED,           /* on IO scheduler merge hash */
         __REQ_MQ_INFLIGHT,      /* track inflight for MQ */
+        __REQ_NO_TIMEOUT,       /* requests may never expire */
         __REQ_NR_BITS,          /* stops here */
 };
 
@@ -243,5 +244,6 @@ enum rq_flag_bits {
 #define REQ_PM                  (1ULL << __REQ_PM)
 #define REQ_HASHED              (1ULL << __REQ_HASHED)
 #define REQ_MQ_INFLIGHT         (1ULL << __REQ_MQ_INFLIGHT)
+#define REQ_NO_TIMEOUT          (1ULL << __REQ_NO_TIMEOUT)
 
 #endif /* __LINUX_BLK_TYPES_H */