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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 | |
| parent | 12cee5a8a29e7263e39953f1d941f723c617ca5f (diff) | |
| download | linux-3.10-3f9e7c140e4c4e75bdeeb8df46dd40e49386c978.tar.gz linux-3.10-3f9e7c140e4c4e75bdeeb8df46dd40e49386c978.tar.bz2 linux-3.10-3f9e7c140e4c4e75bdeeb8df46dd40e49386c978.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>
| -rw-r--r-- | drivers/md/raid5.c | 14 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 1 |
2 files changed, 13 insertions, 2 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c2192a2907e..29493982dbf 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -653,6 +653,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) else bi->bi_sector = (sh->sector + rdev->data_offset); + if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) + bi->bi_rw |= REQ_FLUSH; + bi->bi_flags = 1 << BIO_UPTODATE; bi->bi_idx = 0; bi->bi_io_vec[0].bv_len = STRIPE_SIZE; @@ -1750,7 +1753,9 @@ static void raid5_end_read_request(struct bio * bi, int error) atomic_add(STRIPE_SECTORS, &rdev->corrected_errors); clear_bit(R5_ReadError, &sh->dev[i].flags); clear_bit(R5_ReWrite, &sh->dev[i].flags); - } + } else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) + clear_bit(R5_ReadNoMerge, &sh->dev[i].flags); + if (atomic_read(&rdev->read_errors)) atomic_set(&rdev->read_errors, 0); } else { @@ -1795,7 +1800,11 @@ static void raid5_end_read_request(struct bio * bi, int error) else retry = 1; if (retry) - set_bit(R5_ReadError, &sh->dev[i].flags); + if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) { + set_bit(R5_ReadError, &sh->dev[i].flags); + clear_bit(R5_ReadNoMerge, &sh->dev[i].flags); + } else + set_bit(R5_ReadNoMerge, &sh->dev[i].flags); else { clear_bit(R5_ReadError, &sh->dev[i].flags); clear_bit(R5_ReWrite, &sh->dev[i].flags); @@ -4515,6 +4524,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) return handled; } + set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags); handle_stripe(sh); release_stripe(sh); handled++; diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index f03fb339518..61dbb615c30 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 */ |