kernel/drivers/md, branch linux-4.2.y

Revert "md: allow a partially recovered device to be hot-added to an array."

2015-11-09T22:37:38Z

commit d01552a76d71f9879af448e9142389ee9be6e95b upstream. This reverts commit 7eb418851f3278de67126ea0c427641ab4792c57. This commit is poorly justified, I can find not discusison in email, and it clearly causes a problem. If a device which is being recovered fails and is subsequently re-added to an array, there could easily have been changes to the array *before* the point where the recovery was up to. So the recovery must start again from the beginning. If a spare is being recovered and fails, then when it is re-added we really should do a bitmap-based recovery up to the recovery-offset, and then a full recovery from there. Before this reversion, we only did the "full recovery from there" which is not corect. After this reversion with will do a full recovery from the start, which is safer but not ideal. It will be left to a future patch to arrange the two different styles of recovery. Reported-and-tested-by: Nate Dailey Signed-off-by: NeilBrown Fixes: 7eb418851f32 ("md: allow a partially recovered device to be hot-added to an array.") Signed-off-by: Greg Kroah-Hartman

md/raid5: fix locking in handle_stripe_clean_event()

2015-11-09T22:37:38Z

commit b8a9d66d043ffac116100775a469f05f5158c16f upstream. After commit 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()") __find_stripe() is called under conf->hash_locks + hash. But handle_stripe_clean_event() calls remove_hash() under conf->device_lock. Under some cirscumstances the hash chain can be circuited, and we get an infinite loop with disabled interrupts and locked hash lock in __find_stripe(). This leads to hard lockup on multiple CPUs and following system crash. I was able to reproduce this behavior on raid6 over 6 ssd disks. The devices_handle_discard_safely option should be set to enable trim support. The following script was used: for i in `seq 1 32`; do dd if=/dev/zero of=large$i bs=10M count=100 & done neilb: original was against a 3.x kernel. I forward-ported to 4.3-rc. This verison is suitable for any kernel since Commit: 59fc630b8b5f ("RAID5: batch adjacent full stripe write") (v4.1+). I'll post a version for earlier kernels to stable. Signed-off-by: Roman Gushchin Fixes: 566c09c53455 ("raid5: relieve lock contention in get_active_stripe()") Signed-off-by: NeilBrown Cc: Shaohua Li Signed-off-by: Greg Kroah-Hartman

md/raid10: submit_bio_wait() returns 0 on success

2015-11-09T22:37:38Z

commit 681ab4696062f5aa939c9e04d058732306a97176 upstream. This was introduced with 9e882242c6193ae6f416f2d8d8db0d9126bd996b which changed the return value of submit_bio_wait() to return != 0 on error, but didn't update the caller accordingly. Fixes: 9e882242c6 ("block: Add submit_bio_wait(), remove from md") Reported-by: Bill Kuzeja Signed-off-by: Jes Sorensen Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

md/raid1: submit_bio_wait() returns 0 on success

2015-11-09T22:37:38Z

commit 203d27b0226a05202438ddb39ef0ef1acb14a759 upstream. This was introduced with 9e882242c6193ae6f416f2d8d8db0d9126bd996b which changed the return value of submit_bio_wait() to return != 0 on error, but didn't update the caller accordingly. Fixes: 9e882242c6 ("block: Add submit_bio_wait(), remove from md") Reported-by: Bill Kuzeja Signed-off-by: Jes Sorensen Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm btree: fix leak of bufio-backed block in btree_split_beneath error path

2015-11-09T22:37:36Z

commit 4dcb8b57df3593dcb20481d9d6cf79d1dc1534be upstream. btree_split_beneath()'s error path had an outstanding FIXME that speaks directly to the potential for _not_ cleaning up a previously allocated bufio-backed block. Fix this by releasing the previously allocated bufio block using unlock_block(). Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Signed-off-by: Greg Kroah-Hartman

dm cache: the CLEAN_SHUTDOWN flag was not being set

2015-11-09T22:37:36Z

commit 3201ac452e84a8a368197d648c9b7011e061804a upstream. If the CLEAN_SHUTDOWN flag is not set when a cache is loaded then all cache blocks are marked as dirty and a full writeback occurs. __commit_transaction() is responsible for setting/clearing CLEAN_SHUTDOWN (based the flags_mutator that is passed in). Fix this issue, of the cache's on-disk flags being wrong, by making sure __commit_transaction() does not reset the flags after the mutator has altered the flags in preparation for them being serialized to disk. before: sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags); disk_super->flags = cpu_to_le32(cmd->flags); after: disk_super->flags = cpu_to_le32(cmd->flags); sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags); Reported-by: Bogdan Vasiliev Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm btree remove: fix a bug when rebalancing nodes after removal

2015-11-09T22:37:36Z

commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream. Commit 4c7e309340ff ("dm btree remove: fix bug in redistribute3") wasn't a complete fix for redistribute3(). The redistribute3 function takes 3 btree nodes and shares out the entries evenly between them. If the three nodes in total contained (MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in the center. Fix this issue by being more careful about calculating the target number of entries for the left and right nodes. Unit tested in userspace using this program: https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm thin: fix missing pool reference count decrement in pool_ctr error path

2015-10-27T00:53:42Z

commit ba30670f4d5292c4e7f7980bbd5071f7c4794cdd upstream. Fixes: ac8c3f3df ("dm thin: generate event when metadata threshold passed") Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache: fix NULL pointer when switching from cleaner policy

2015-10-22T21:49:34Z

commit 2bffa1503c5c06192eb1459180fac4416575a966 upstream. The cleaner policy doesn't make use of the per cache block hint space in the metadata (unlike the other policies). When switching from the cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block) was observed. The crash was caused by bugs in dm-cache-metadata.c when trying to skip creation of the hint btree. The minimal fix is to change hint size for the cleaner policy to 4 bytes (only hint size supported). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm: fix AB-BA deadlock in __dm_destroy()

2015-10-22T21:49:34Z

commit 2a708cff93f1845b9239bc7d6310aef54e716c6a upstream. __dm_destroy() takes io_barrier SRCU lock (dm_get_live_table) and suspend_lock in reverse order. Doing so can cause AB-BA deadlock: __dm_destroy dm_swap_table --------------------------------------------------- mutex_lock(suspend_lock) dm_get_live_table() srcu_read_lock(io_barrier) dm_sync_table() synchronize_srcu(io_barrier) .. waiting for dm_put_live_table() mutex_lock(suspend_lock) .. waiting for suspend_lock Fix this by taking the locks in proper order. Signed-off-by: Jun'ichi Nomura Fixes: ab7c7bb6f4ab ("dm: hold suspend_lock while suspending device during device deletion") Acked-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman