diff options
| -rw-r--r-- | drivers/md/raid5.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 9716319cc477..77dfd720aaa0 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4632,8 +4632,12 @@ static int raid5_mergeable_bvec(struct mddev *mddev, unsigned int chunk_sectors = mddev->chunk_sectors; unsigned int bio_sectors = bvm->bi_size >> 9; - if ((bvm->bi_rw & 1) == WRITE) - return biovec->bv_len; /* always allow writes to be mergeable */ + /* + * always allow writes to be mergeable, read as well if array + * is degraded as we'll go through stripe cache anyway. + */ + if ((bvm->bi_rw & 1) == WRITE || mddev->degraded) + return biovec->bv_len; if (mddev->new_chunk_sectors < mddev->chunk_sectors) chunk_sectors = mddev->new_chunk_sectors; @@ -5110,7 +5114,12 @@ static void make_request(struct mddev *mddev, struct bio * bi) md_write_start(mddev, bi); - if (rw == READ && + /* + * If array is degraded, better not do chunk aligned read because + * later we might have to read it again in order to reconstruct + * data on failed drives. + */ + if (rw == READ && mddev->degraded == 0 && mddev->reshape_position == MaxSector && chunk_aligned_read(mddev,bi)) return; |