diff options
| author | NeilBrown <neilb@suse.de> | 2011-12-23 10:17:52 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2011-12-23 10:17:52 +1100 |
| commit | 671488cc25f7c194c7c7a9f258bab1df17a6ff69 (patch) | |
| tree | 00bec63c7789dbf7439418ee903490d6ee076a70 /drivers/md/raid5.c | |
| parent | 2d78f8c451785f030ac1676a18691896b59c69d8 (diff) | |
| download | blackbird-op-linux-671488cc25f7c194c7c7a9f258bab1df17a6ff69.tar.gz blackbird-op-linux-671488cc25f7c194c7c7a9f258bab1df17a6ff69.zip | |
md/raid5: allow each slot to have an extra replacement device
Just enhance data structures to record a second device per slot to be
used as a 'replacement' device, replacing the original.
We also have a second bio in each slot in each stripe_head. This will
only be used when writing to the array - we need to write to both the
original and the replacement at the same time, so will need two bios.
For now, only try using the replacement drive for aligned-reads.
In this case, we prefer the replacement if it has been recovered far
enough, otherwise use the original.
This includes a small enhancement. Previously we would only do
aligned reads if the target device was fully recovered. Now we also
do them if it has recovered far enough.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 6b9fc58e8f2d..94bc35ba4c81 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3594,6 +3594,7 @@ static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio) int dd_idx; struct bio* align_bi; struct md_rdev *rdev; + sector_t end_sector; if (!in_chunk_boundary(mddev, raid_bio)) { pr_debug("chunk_aligned_read : non aligned\n"); @@ -3618,9 +3619,19 @@ static int chunk_aligned_read(struct mddev *mddev, struct bio * raid_bio) 0, &dd_idx, NULL); + end_sector = align_bi->bi_sector + (align_bi->bi_size >> 9); rcu_read_lock(); - rdev = rcu_dereference(conf->disks[dd_idx].rdev); - if (rdev && test_bit(In_sync, &rdev->flags)) { + rdev = rcu_dereference(conf->disks[dd_idx].replacement); + if (!rdev || test_bit(Faulty, &rdev->flags) || + rdev->recovery_offset < end_sector) { + rdev = rcu_dereference(conf->disks[dd_idx].rdev); + if (rdev && + (test_bit(Faulty, &rdev->flags) || + !(test_bit(In_sync, &rdev->flags) || + rdev->recovery_offset >= end_sector))) + rdev = NULL; + } + if (rdev) { sector_t first_bad; int bad_sectors; |
