In preparation for Open-Channel SSDs. We introduce a special request for
open-channel ssd targets that must perform garbage collection.
Requests are divided into two types. The user and target specific. User
IOs are from fs, user-space, etc. While target specific are IOs that are
issued in the background by targets. Usually garbage collection actions.
For the target to issue garbage collection requests, it is a requirement
that a logical address is locked over two requests. One read and one
write. If a write to the logical address comes in from user-space, a
race-condition might occur and garbage collection will write out-dated
data.
By introducing this flag, the target can manually control locking of
logical addresses.
Signed-off-by: Matias Bjørling <m@xxxxxxxxxxx>
---
include/linux/blk_types.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 272c17e..25c6e02 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -195,6 +195,7 @@ enum rq_flag_bits {
__REQ_HASHED, /* on IO scheduler merge hash */
__REQ_MQ_INFLIGHT, /* track inflight for MQ */
__REQ_NO_TIMEOUT, /* requests may never expire */
+ __REQ_NVM_GC, /* request is a nvm gc request */
__REQ_NR_BITS, /* stops here */
};
@@ -215,7 +216,7 @@ 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_NVM_GC)
#define REQ_CLONE_MASK REQ_COMMON_MASK
#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME)
@@ -249,5 +250,5 @@ enum rq_flag_bits {
#define REQ_HASHED (1ULL << __REQ_HASHED)
#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)
#define REQ_NO_TIMEOUT (1ULL << __REQ_NO_TIMEOUT)
-
+#define REQ_NVM_GC (1ULL << __REQ_NVM_GC)
#endif /* __LINUX_BLK_TYPES_H */
--
1.9.1
--
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