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authorMartin K. Petersen <martin.petersen@oracle.com>2016-02-04 00:52:12 -0500
committerMartin K. Petersen <martin.petersen@oracle.com>2016-02-04 22:42:58 -0500
commit0fb5b1fb30fba3671dd5b1489d78e93e08d62e4e (patch)
tree090ebf83b190bff02e29a43f8611503d066e33c5 /include/linux/blkdev.h
parent82c43310508eb19eb41fe7862e89afeb74030b84 (diff)
block/sd: Return -EREMOTEIO when WRITE SAME and DISCARD are disabled
When a storage device rejects a WRITE SAME command we will disable write same functionality for the device and return -EREMOTEIO to the block layer. -EREMOTEIO will in turn prevent DM from retrying the I/O and/or failing the path. Yiwen Jiang discovered a small race where WRITE SAME requests issued simultaneously would cause -EIO to be returned. This happened because any requests being prepared after WRITE SAME had been disabled for the device caused us to return BLKPREP_KILL. The latter caused the block layer to return -EIO upon completion. To overcome this we introduce BLKPREP_INVALID which indicates that this is an invalid request for the device. blk_peek_request() is modified to return -EREMOTEIO in that case. Reported-by: Yiwen Jiang <jiangyiwen@huawei.com> Suggested-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Hannes Reinicke <hare@suse.de> Reviewed-by: Ewan Milne <emilne@redhat.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/linux/blkdev.h')
-rw-r--r--include/linux/blkdev.h9
1 files changed, 6 insertions, 3 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d372ea87ead5..a9b643a0647f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -681,9 +681,12 @@ static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
/*
* q->prep_rq_fn return values
*/
-#define BLKPREP_OK 0 /* serve it */
-#define BLKPREP_KILL 1 /* fatal error, kill */
-#define BLKPREP_DEFER 2 /* leave on queue */
+enum {
+ BLKPREP_OK, /* serve it */
+ BLKPREP_KILL, /* fatal error, kill, return -EIO */
+ BLKPREP_DEFER, /* leave on queue */
+ BLKPREP_INVALID, /* invalid command, kill, return -EREMOTEIO */
+};
extern unsigned long blk_max_low_pfn, blk_max_pfn;