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| author | majianpeng <majianpeng@gmail.com> | 2012-07-31 10:04:21 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2012-07-31 10:04:21 +1000 |
| commit | 3f9e7c140e4c4e75bdeeb8df46dd40e49386c978 (patch) | |
| tree | 81585524e1ce341eb518716c0702a6dfd64a19ef /drivers/md/raid5.h | |
| parent | 12cee5a8a29e7263e39953f1d941f723c617ca5f (diff) | |
| download | lwn-3f9e7c140e4c4e75bdeeb8df46dd40e49386c978.tar.gz lwn-3f9e7c140e4c4e75bdeeb8df46dd40e49386c978.zip | |
raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
Because bios will merge at block-layer,so bios-error may caused by other
bio which be merged into to the same request.
Using this flag,it will find exactly error-sector and not do redundant
operation like re-write and re-read.
V0->V1:Using REQ_FLUSH instead REQ_NOMERGE avoid bio merging at block
layer.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.h')
| -rw-r--r-- | drivers/md/raid5.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index f03fb3395183..61dbb615c30b 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -274,6 +274,7 @@ enum r5dev_flags { R5_Wantwrite, R5_Overlap, /* There is a pending overlapping request * on this block */ + R5_ReadNoMerge, /* prevent bio from merging in block-layer */ R5_ReadError, /* seen a read error here recently */ R5_ReWrite, /* have tried to over-write the readerror */ |