From a9ad8526bb1af0741a5c0e01155dac08e7bdde60 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Tue, 24 Apr 2012 10:23:13 +1000 Subject: [PATCH 1/3] DM RAID: Use safe version of rdev_for_each Fix segfault caused by using rdev_for_each instead of rdev_for_each_safe Commit dafb20fa34320a472deb7442f25a0c086e0feb33 mistakenly replaced a safe iterator with an unsafe one when making some macro changes. Signed-off-by: Jonathan Brassow Signed-off-by: NeilBrown --- drivers/md/dm-raid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index b0ba52459ed738..68965e663248e2 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -859,7 +859,7 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) int ret; unsigned redundancy = 0; struct raid_dev *dev; - struct md_rdev *rdev, *freshest; + struct md_rdev *rdev, *tmp, *freshest; struct mddev *mddev = &rs->md; switch (rs->raid_type->level) { @@ -877,7 +877,7 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) } freshest = NULL; - rdev_for_each(rdev, mddev) { + rdev_for_each_safe(rdev, tmp, mddev) { if (!rdev->meta_bdev) continue; From ed209584c38fb74b7eecc03e5b1bfe674e591bd8 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 24 Apr 2012 10:23:14 +1000 Subject: [PATCH 2/3] md: don't call ->add_disk unless there is good reason. Commit 7bfec5f35c68121e7b18 md/raid5: If there is a spare and a want_replacement device, start replacement. cause md_check_recovery to call ->add_disk much more often. Instead of only when the array is degraded, it is now called whenever md_check_recovery finds anything useful to do, which includes updating the metadata for clean<->dirty transition. This causes unnecessary work, and causes info messages from ->add_disk to be reported much too often. So refine md_check_recovery to only do any actual recovery checking (including ->add_disk) if MD_RECOVERY_NEEDED is set. This fix is suitable for 3.3.y: Cc: stable@vger.kernel.org Reported-by: Jan Ceuleers Signed-off-by: NeilBrown --- drivers/md/md.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index b572e1e386ceab..8beb19c3bb44d1 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7560,14 +7560,14 @@ void md_check_recovery(struct mddev *mddev) * any transients in the value of "sync_action". */ set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); - clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); /* Clear some bits that don't mean anything, but * might be left set */ clear_bit(MD_RECOVERY_INTR, &mddev->recovery); clear_bit(MD_RECOVERY_DONE, &mddev->recovery); - if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) + if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) || + test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) goto unlock; /* no recovery is running. * remove any failed drives, then From 30b8aa9172dfeaac6d77897c67ee9f9fc574cdbb Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 24 Apr 2012 10:23:16 +1000 Subject: [PATCH 3/3] md: fix possible corruption of array metadata on shutdown. commit c744a65c1e2d59acc54333ce8 md: don't set md arrays to readonly on shutdown. removed the possibility of a 'BUG' when data is written to an array that has just been switched to read-only, but also introduced the possibility that the array metadata could be corrupted. If, when md_notify_reboot gets the mddev lock, the array is in a state where it is assembled but hasn't been started (as can happen if the personality module is not available, or in other unusual situations), then incorrect metadata will be written out making it impossible to re-assemble the array. So only call __md_stop_writes() if the array has actually been activated. This patch is needed for any stable kernel which has had the above commit applied. Cc: stable@vger.kernel.org Reported-by: Christoph Nelles Signed-off-by: NeilBrown --- drivers/md/md.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 8beb19c3bb44d1..477eb2e180c031 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8140,7 +8140,8 @@ static int md_notify_reboot(struct notifier_block *this, for_each_mddev(mddev, tmp) { if (mddev_trylock(mddev)) { - __md_stop_writes(mddev); + if (mddev->pers) + __md_stop_writes(mddev); mddev->safemode = 2; mddev_unlock(mddev); }