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| author |   Dan Williams <dan.j.williams@intel.com> | 2008-04-30 00:52:32 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:33 -0700 |
| commit | 6bfe0b499082fd3950429017cd8ebf2a6c458aa5 (patch) | |
| tree | 81476cf7f7ddbea135bdb93729e0bffae0e7c163 /drivers/md/raid1.c | |
| parent | md: prevent duplicates in bind_rdev_to_array (diff) | |
| download | linux-dev-6bfe0b499082fd3950429017cd8ebf2a6c458aa5.tar.xz linux-dev-6bfe0b499082fd3950429017cd8ebf2a6c458aa5.zip | |
md: support blocking writes to an array on device failure
Allows a userspace metadata handler to take action upon detecting a device
failure.
Based on an original patch by Neil Brown.
Changes:
-added blocked_wait waitqueue to rdev
-don't qualify Blocked with Faulty always let userspace block writes
-added md_wait_for_blocked_rdev to wait for the block device to be clear, if
userspace misses the notification another one is sent every 5 seconds
-set MD_RECOVERY_NEEDED after clearing "blocked"
-kill DoBlock flag, just test mddev->external
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md/raid1.c')
| -rw-r--r-- | drivers/md/raid1.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 9fd473a6dbf5..6778b7cb39bd 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -773,7 +773,6 @@ static int make_request(struct request_queue *q, struct bio * bio) r1bio_t *r1_bio; struct bio *read_bio; int i, targets = 0, disks; - mdk_rdev_t *rdev; struct bitmap *bitmap = mddev->bitmap; unsigned long flags; struct bio_list bl; @@ -781,6 +780,7 @@ static int make_request(struct request_queue *q, struct bio * bio) const int rw = bio_data_dir(bio); const int do_sync = bio_sync(bio); int do_barriers; + mdk_rdev_t *blocked_rdev; /* * Register the new request and wait if the reconstruction @@ -862,10 +862,17 @@ static int make_request(struct request_queue *q, struct bio * bio) first = 0; } #endif + retry_write: + blocked_rdev = NULL; rcu_read_lock(); for (i = 0; i < disks; i++) { - if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL && - !test_bit(Faulty, &rdev->flags)) { + mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); + if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { + atomic_inc(&rdev->nr_pending); + blocked_rdev = rdev; + break; + } + if (rdev && !test_bit(Faulty, &rdev->flags)) { atomic_inc(&rdev->nr_pending); if (test_bit(Faulty, &rdev->flags)) { rdev_dec_pending(rdev, mddev); @@ -878,6 +885,20 @@ static int make_request(struct request_queue *q, struct bio * bio) } rcu_read_unlock(); + if (unlikely(blocked_rdev)) { + /* Wait for this device to become unblocked */ + int j; + + for (j = 0; j < i; j++) + if (r1_bio->bios[j]) + rdev_dec_pending(conf->mirrors[j].rdev, mddev); + + allow_barrier(conf); + md_wait_for_blocked_rdev(blocked_rdev, mddev); + wait_barrier(conf); + goto retry_write; + } + BUG_ON(targets == 0); /* we never fail the last device */ if (targets < conf->raid_disks) { |