diff options
| author | NeilBrown <neilb@suse.com> | 2016-06-02 16:19:53 +1000 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2016-06-13 11:54:21 -0700 |
| commit | f5b67ae86ee317db20c0e10d54f16a0bbbd3207d (patch) | |
| tree | 8db4539e9c9f05624f2b198ddd1ccce54b281ce6 | |
| parent | 40cf2123c57928c3ec0626c49bef97ebdbce008e (diff) | |
md: be extra careful not to take a reference to a Faulty device.
It is important that we never increment rdev->nr_pending on a Faulty
device as ->hot_remove_disk() assumes that once the Faulty flag is visible
no code will take a new reference.
Some places take a new reference after only check In_sync. This should
be safe as the two are changed together. However to make the code more
obviously safe, add checks for 'Faulty' as well.
Note: the actual rule is:
Never increment nr_pending if Faulty is set and Blocked is clear,
never clear Faulty, and never set Blocked without holding a reference
through nr_pending.
fix build error (Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
| -rw-r--r-- | drivers/md/multipath.c | 3 | ||||
| -rw-r--r-- | drivers/md/raid10.c | 6 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 3 |
3 files changed, 10 insertions, 2 deletions
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c index 69244de2036b..7eb9972a37e6 100644 --- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -43,7 +43,8 @@ static int multipath_map (struct mpconf *conf) rcu_read_lock(); for (i = 0; i < disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev); - if (rdev && test_bit(In_sync, &rdev->flags)) { + if (rdev && test_bit(In_sync, &rdev->flags) && + !test_bit(Faulty, &rdev->flags)) { atomic_inc(&rdev->nr_pending); rcu_read_unlock(); return i; diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 526c1d82246e..34facda18e72 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -2287,6 +2287,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 rdev = rcu_dereference(conf->mirrors[d].rdev); if (rdev && test_bit(In_sync, &rdev->flags) && + !test_bit(Faulty, &rdev->flags) && is_badblock(rdev, r10_bio->devs[sl].addr + sect, s, &first_bad, &bad_sectors) == 0) { atomic_inc(&rdev->nr_pending); @@ -2339,6 +2340,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 d = r10_bio->devs[sl].devnum; rdev = rcu_dereference(conf->mirrors[d].rdev); if (!rdev || + test_bit(Faulty, &rdev->flags) || !test_bit(In_sync, &rdev->flags)) continue; @@ -2378,6 +2380,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 d = r10_bio->devs[sl].devnum; rdev = rcu_dereference(conf->mirrors[d].rdev); if (!rdev || + test_bit(Faulty, &rdev->flags) || !test_bit(In_sync, &rdev->flags)) continue; @@ -2953,6 +2956,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, mreplace = rcu_dereference(mirror->replacement); if ((mrdev == NULL || + test_bit(Faulty, &mrdev->flags) || test_bit(In_sync, &mrdev->flags)) && (mreplace == NULL || test_bit(Faulty, &mreplace->flags))) { @@ -2971,6 +2975,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, rcu_read_unlock(); continue; } + if (mreplace && test_bit(Faulty, &mreplace->flags)) + mreplace = NULL; /* Unless we are doing a full sync, or a replacement * we only need to recover the block if it is set in * the bitmap diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c07b22e8d946..f6a191aaaa91 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3080,7 +3080,8 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, struct md_rdev *rdev; rcu_read_lock(); rdev = rcu_dereference(conf->disks[i].rdev); - if (rdev && test_bit(In_sync, &rdev->flags)) + if (rdev && test_bit(In_sync, &rdev->flags) && + !test_bit(Faulty, &rdev->flags)) atomic_inc(&rdev->nr_pending); else rdev = NULL; |