raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
authormajianpeng <majianpeng@gmail.com>
Tue, 31 Jul 2012 00:04:21 +0000 (10:04 +1000)
committerNeilBrown <neilb@suse.de>
Tue, 31 Jul 2012 00:04:21 +0000 (10:04 +1000)
commit3f9e7c140e4c4e75bdeeb8df46dd40e49386c978
tree81585524e1ce341eb518716c0702a6dfd64a19ef
parent12cee5a8a29e7263e39953f1d941f723c617ca5f
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>
drivers/md/raid5.c
drivers/md/raid5.h