@@ -1267,18 +1267,21 @@ retry_write:
blocked_rdev = rrdev;
break;
}
+ if (rdev && (test_bit(Faulty, &rdev->flags)
+ || test_bit(Unmerged, &rdev->flags)))
+ rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)
|| test_bit(Unmerged, &rrdev->flags)))
rrdev = NULL;
r10_bio->devs[i].bio = NULL;
r10_bio->devs[i].repl_bio = NULL;
- if (!rdev || test_bit(Faulty, &rdev->flags) ||
- test_bit(Unmerged, &rdev->flags)) {
+
+ if (!rdev && !rrdev) {
set_bit(R10BIO_Degraded, &r10_bio->state);
continue;
}
- if (test_bit(WriteErrorSeen, &rdev->flags)) {
+ if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
@@ -1320,8 +1323,10 @@ retry_write:
max_sectors = good_sectors;
}
}
- r10_bio->devs[i].bio = bio;
- atomic_inc(&rdev->nr_pending);
+ if (rdev) {
+ r10_bio->devs[i].bio = bio;
+ atomic_inc(&rdev->nr_pending);
+ }
if (rrdev) {
r10_bio->devs[i].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
@@ -1377,58 +1382,58 @@ retry_write:
for (i = 0; i < conf->copies; i++) {
struct bio *mbio;
int d = r10_bio->devs[i].devnum;
- if (!r10_bio->devs[i].bio)
- continue;
-
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
- r10_bio->devs[i].bio = mbio;
-
- mbio->bi_sector = (r10_bio->devs[i].addr+
- choose_data_offset(r10_bio,
- conf->mirrors[d].rdev));
- mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua;
- mbio->bi_private = r10_bio;
-
- atomic_inc(&r10_bio->remaining);
- spin_lock_irqsave(&conf->device_lock, flags);
- bio_list_add(&conf->pending_bio_list, mbio);
- conf->pending_count++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (!mddev_check_plugged(mddev))
- md_wakeup_thread(mddev->thread);
-
- if (!r10_bio->devs[i].repl_bio)
- continue;
+ if (r10_bio->devs[i].bio) {
+ struct md_rdev *rdev = conf->mirrors[d].rdev;
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr+
+ choose_data_offset(r10_bio,
+ rdev));
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
+ mbio->bi_private = r10_bio;
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
- r10_bio->devs[i].repl_bio = mbio;
+ atomic_inc(&r10_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (!mddev_check_plugged(mddev))
+ md_wakeup_thread(mddev->thread);
+ }
- /* We are actively writing to the original device
- * so it cannot disappear, so the replacement cannot
- * become NULL here
- */
- mbio->bi_sector = (r10_bio->devs[i].addr +
- choose_data_offset(
- r10_bio,
- conf->mirrors[d].replacement));
- mbio->bi_bdev = conf->mirrors[d].replacement->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua;
- mbio->bi_private = r10_bio;
+ if (r10_bio->devs[i].repl_bio) {
+ struct md_rdev *rdev = conf->mirrors[d].replacement;
+ if (rdev == NULL) {
+ /* Replacement just got moved to main 'rdev' */
+ smp_mb();
+ rdev = conf->mirrors[d].rdev;
+ }
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].repl_bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr +
+ choose_data_offset(
+ r10_bio, rdev));
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua;
+ mbio->bi_private = r10_bio;
- atomic_inc(&r10_bio->remaining);
- spin_lock_irqsave(&conf->device_lock, flags);
- bio_list_add(&conf->pending_bio_list, mbio);
- conf->pending_count++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (!mddev_check_plugged(mddev))
- md_wakeup_thread(mddev->thread);
+ atomic_inc(&r10_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (!mddev_check_plugged(mddev))
+ md_wakeup_thread(mddev->thread);
+ }
}
/* Don't remove the bias on 'remaining' (one_write_done) until
This is a note to let you know that I have just added a patch titled md/raid10: close race that lose writes lost when replacement to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From 649964dd53307f85ff5eef5ea4fe65e6b9e59e44 Mon Sep 17 00:00:00 2001 From: NeilBrown <neilb@suse.de> Date: Thu, 22 Nov 2012 14:42:49 +1100 Subject: [PATCH] md/raid10: close race that lose writes lost when replacement completes. commit e7c0c3fa29280d62aa5e11101a674bb3064bd791 upstream. When a replacement operation completes there is a small window when the original device is marked 'faulty' and the replacement still looks like a replacement. The faulty should be removed and the replacement moved in place very quickly, bit it isn't instant. So the code write out to the array must handle the possibility that the only working device for some slot in the replacement - but it doesn't. If the primary device is faulty it just gives up. This can lead to corruption. So make the code more robust: if either the primary or the replacement is present and working, write to them. Only when neither are present do we give up. This bug has been present since replacement was introduced in 3.3, so it is suitable for any -stable kernel since then. Reported-by: "George Spelvin" <linux@horizon.com> Signed-off-by: NeilBrown <neilb@suse.de> [ herton: hairy code adjustment on 3rd hunk (conf->copies for loop) ] Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- drivers/md/raid10.c | 113 +++++++++++++++++++++++++++------------------------ 1 file changed, 59 insertions(+), 54 deletions(-) -- 1.7.9.5