linux-stable.git/drivers/md, branch v5.4.59

bcache: fix super block seq numbers comparision in register_cache_set()

2020-08-19T06:16:05+00:00

[ Upstream commit 117f636ea695270fe492d0c0c9dfadc7a662af47 ]

In register_cache_set(), c is pointer to struct cache_set, and ca is
pointer to struct cache, if ca->sb.seq > c->sb.seq, it means this
registering cache has up to date version and other members, the in-
memory version and other members should be updated to the newer value.

But current implementation makes a cache set only has a single cache
device, so the above assumption works well except for a special case.
The execption is when a cache device new created and both ca->sb.seq and
c->sb.seq are 0, because the super block is never flushed out yet. In
the location for the following if() check,
2156         if (ca->sb.seq > c->sb.seq) {
2157                 c->sb.version           = ca->sb.version;
2158                 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
2159                 c->sb.flags             = ca->sb.flags;
2160                 c->sb.seq               = ca->sb.seq;
2161                 pr_debug("set version = %llu\n", c->sb.version);
2162         }
c->sb.version is not initialized yet and valued 0. When ca->sb.seq is 0,
the if() check will fail (because both values are 0), and the cache set
version, set_uuid, flags and seq won't be updated.

The above problem is hiden for current code, because the bucket size is
compatible among different super block version. And the next time when
running cache set again, ca->sb.seq will be larger than 0 and cache set
super block version will be updated properly.

But if the large bucket feature is enabled,  sb->bucket_size is the low
16bits of the bucket size. For a power of 2 value, when the actual
bucket size exceeds 16bit width, sb->bucket_size will always be 0. Then
read_super_common() will fail because the if() check to
is_power_of_2(sb->bucket_size) is false. This is how the long time
hidden bug is triggered.

This patch modifies the if() check to the following way,
2156         if (ca->sb.seq > c->sb.seq || c->sb.seq == 0) {
Then cache set's version, set_uuid, flags and seq will always be updated
corectly including for a new created cache device.

Signed-off-by: Coly Li 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

md-cluster: fix wild pointer of unlock_all_bitmaps()

2020-08-19T06:16:01+00:00

[ Upstream commit 60f80d6f2d07a6d8aee485a1d1252327eeee0c81 ]

reproduction steps:
```
node1 # mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda
/dev/sdb
node2 # mdadm -A /dev/md0 /dev/sda /dev/sdb
node1 # mdadm -G /dev/md0 -b none
mdadm: failed to remove clustered bitmap.
node1 # mdadm -S --scan
^C  <==== mdadm hung & kernel crash
```

kernel stack:
```
[  335.230657] general protection fault: 0000 [#1] SMP NOPTI
[...]
[  335.230848] Call Trace:
[  335.230873]  ? unlock_all_bitmaps+0x5/0x70 [md_cluster]
[  335.230886]  unlock_all_bitmaps+0x3d/0x70 [md_cluster]
[  335.230899]  leave+0x10f/0x190 [md_cluster]
[  335.230932]  ? md_super_wait+0x93/0xa0 [md_mod]
[  335.230947]  ? leave+0x5/0x190 [md_cluster]
[  335.230973]  md_cluster_stop+0x1a/0x30 [md_mod]
[  335.230999]  md_bitmap_free+0x142/0x150 [md_mod]
[  335.231013]  ? _cond_resched+0x15/0x40
[  335.231025]  ? mutex_lock+0xe/0x30
[  335.231056]  __md_stop+0x1c/0xa0 [md_mod]
[  335.231083]  do_md_stop+0x160/0x580 [md_mod]
[  335.231119]  ? 0xffffffffc05fb078
[  335.231148]  md_ioctl+0xa04/0x1930 [md_mod]
[  335.231165]  ? filename_lookup+0xf2/0x190
[  335.231179]  blkdev_ioctl+0x93c/0xa10
[  335.231205]  ? _cond_resched+0x15/0x40
[  335.231214]  ? __check_object_size+0xd4/0x1a0
[  335.231224]  block_ioctl+0x39/0x40
[  335.231243]  do_vfs_ioctl+0xa0/0x680
[  335.231253]  ksys_ioctl+0x70/0x80
[  335.231261]  __x64_sys_ioctl+0x16/0x20
[  335.231271]  do_syscall_64+0x65/0x1f0
[  335.231278]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
```

Signed-off-by: Zhao Heming 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

md: raid0/linear: fix dereference before null check on pointer mddev

2020-08-19T06:15:58+00:00

[ Upstream commit 9a5a85972c073f720d81a7ebd08bfe278e6e16db ]

Pointer mddev is being dereferenced with a test_bit call before mddev
is being null checked, this may cause a null pointer dereference. Fix
this by moving the null pointer checks to sanity check mddev before
it is dereferenced.

Addresses-Coverity: ("Dereference before null check")
Fixes: 62f7b1989c02 ("md raid0/linear: Mark array as 'broken' and fail BIOs if a member is gone")
Signed-off-by: Colin Ian King 
Reviewed-by: Guilherme G. Piccoli 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

dm integrity: fix integrity recalculation that is improperly skipped

2020-07-29T08:18:45+00:00

commit 5df96f2b9f58a5d2dc1f30fe7de75e197f2c25f2 upstream.

Commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 ("dm: report suspended
device during destroy") broke integrity recalculation.

The problem is dm_suspended() returns true not only during suspend,
but also during resume. So this race condition could occur:
1. dm_integrity_resume calls queue_work(ic->recalc_wq, &ic->recalc_work)
2. integrity_recalc (&ic->recalc_work) preempts the current thread
3. integrity_recalc calls if (unlikely(dm_suspended(ic->ti))) goto unlock_ret;
4. integrity_recalc exits and no recalculating is done.

To fix this race condition, add a function dm_post_suspending that is
only true during the postsuspend phase and use it instead of
dm_suspended().

Signed-off-by: Mikulas Patocka 
Fixes: adc0daad366b ("dm: report suspended device during destroy")
Cc: stable vger kernel org # v4.18+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: use bio_uninit instead of bio_disassociate_blkg

2020-07-29T08:18:28+00:00

[ Upstream commit 382761dc6312965a11f82f2217e16ec421bf17ae ]

bio_uninit is the proper API to clean up a BIO that has been allocated
on stack or inside a structure that doesn't come from the BIO allocator.
Switch dm to use that instead of bio_disassociate_blkg, which really is
an implementation detail.  Note that the bio_uninit calls are also moved
to the two callers of __send_empty_flush, so that they better pair with
the bio_init calls used to initialize them.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

dm writecache: reject asynchronous pmem devices

2020-07-16T06:16:47+00:00

commit a46624580376a3a0beb218d94cbc7f258696e29f upstream.

DM writecache does not handle asynchronous pmem. Reject it when
supplied as cache.

Link: https://lore.kernel.org/linux-nvdimm/87lfk5hahc.fsf@linux.ibm.com/
Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver")
Signed-off-by: Michal Suchanek 
Acked-by: Mikulas Patocka 
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: use noio when sending kobject event

2020-07-16T06:16:46+00:00

commit 6958c1c640af8c3f40fa8a2eee3b5b905d95b677 upstream.

kobject_uevent may allocate memory and it may be called while there are dm
devices suspended. The allocation may recurse into a suspended device,
causing a deadlock. We must set the noio flag when sending a uevent.

The observed deadlock was reported here:
https://www.redhat.com/archives/dm-devel/2020-March/msg00025.html

Reported-by: Khazhismel Kumykov 
Reported-by: Tahsin Erdogan 
Reported-by: Gabriel Krisman Bertazi 
Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm zoned: assign max_io_len correctly

2020-07-09T07:37:57+00:00

commit 7b2377486767503d47265e4d487a63c651f6b55d upstream.

The unit of max_io_len is sector instead of byte (spotted through
code review), so fix it.

Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao 
Reviewed-by: Damien Le Moal 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: add cond_resched to loop in persistent_memory_claim()

2020-06-30T19:37:12+00:00

commit d35bd764e6899a7bea71958f08d16cea5bfa1919 upstream.

Add cond_resched() to a loop that fills in the mapper memory area
because the loop can be executed many times.

Fixes: 48debafe4f2fe ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: correct uncommitted_block when discarding uncommitted entry

2020-06-30T19:37:12+00:00

commit 39495b12ef1cf602e6abd350dce2ef4199906531 upstream.

When uncommitted entry has been discarded, correct wc->uncommitted_block
for getting the exact number.

Fixes: 48debafe4f2fe ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Huaisheng Ye 
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman