5689 Commits

Author SHA1 Message Date
Ye Bin
2c00ee626e dm thin metadata: Avoid returning cmd->bm wild pointer on error
commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream.

Maybe __create_persistent_data_objects() caller will use PTR_ERR as a
pointer, it will lead to some strange things.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:04:31 +02:00
Ye Bin
67f03c3d68 dm cache metadata: Avoid returning cmd->bm wild pointer on error
commit d16ff19e69ab57e08bf908faaacbceaf660249de upstream.

Maybe __create_persistent_data_objects() caller will use PTR_ERR as a
pointer, it will lead to some strange things.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:04:31 +02:00
Mikulas Patocka
154096e996 dm writecache: handle DAX to partitions on persistent memory correctly
commit f9e040efcc28309e5c592f7e79085a9a52e31f58 upstream.

The function dax_direct_access doesn't take partitions into account,
it always maps pages from the beginning of the device. Therefore,
persistent_memory_claim() must get the partition offset using
get_start_sect() and add it to the page offsets passed to
dax_direct_access().

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-09 19:04:31 +02:00
Ming Lei
a24e10abad dm rq: don't call blk_mq_queue_stopped() in dm_stop_queue()
[ Upstream commit e766668c6cd49d741cfb49eaeb38998ba34d27bc ]

dm_stop_queue() only uses blk_mq_quiesce_queue() so it doesn't
formally stop the blk-mq queue; therefore there is no point making the
blk_mq_queue_stopped() check -- it will never be stopped.

In addition, even though dm_stop_queue() actually tries to quiesce hw
queues via blk_mq_quiesce_queue(), checking with blk_queue_quiesced()
to avoid unnecessary queue quiesce isn't reliable because: the
QUEUE_FLAG_QUIESCED flag is set before synchronize_rcu() and
dm_stop_queue() may be called when synchronize_rcu() from another
blk_mq_quiesce_queue() is in-progress.

Fixes: 7b17c2f7292ba ("dm: Fix a race condition related to stopping and starting queues")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:35 +02:00
Coly Li
2a72c28331 bcache: fix overflow in offset_to_stripe()
commit 7a1481267999c02abf4a624515c1b5c7c1fccbd6 upstream.

offset_to_stripe() returns the stripe number (in type unsigned int) from
an offset (in type uint64_t) by the following calculation,
	do_div(offset, d->stripe_size);
For large capacity backing device (e.g. 18TB) with small stripe size
(e.g. 4KB), the result is 4831838208 and exceeds UINT_MAX. The actual
returned value which caller receives is 536870912, due to the overflow.

Indeed in bcache_device_init(), bcache_device->nr_stripes is limited in
range [1, INT_MAX]. Therefore all valid stripe numbers in bcache are
in range [0, bcache_dev->nr_stripes - 1].

This patch adds a upper limition check in offset_to_stripe(): the max
valid stripe number should be less than bcache_device->nr_stripes. If
the calculated stripe number from do_div() is equal to or larger than
bcache_device->nr_stripe, -EINVAL will be returned. (Normally nr_stripes
is less than INT_MAX, exceeding upper limitation doesn't mean overflow,
therefore -EOVERFLOW is not used as error code.)

This patch also changes nr_stripes' type of struct bcache_device from
'unsigned int' to 'int', and return value type of offset_to_stripe()
from 'unsigned int' to 'int', to match their exact data ranges.

All locations where bcache_device->nr_stripes and offset_to_stripe() are
referenced also get updated for the above type change.

Reported-and-tested-by: Ken Raeburn <raeburn@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1783075
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:32 +02:00
Coly Li
d6e2394ce6 bcache: allocate meta data pages as compound pages
commit 5fe48867856367142d91a82f2cbf7a57a24cbb70 upstream.

There are some meta data of bcache are allocated by multiple pages,
and they are used as bio bv_page for I/Os to the cache device. for
example cache_set->uuids, cache->disk_buckets, journal_write->data,
bset_tree->data.

For such meta data memory, all the allocated pages should be treated
as a single memory block. Then the memory management and underlying I/O
code can treat them more clearly.

This patch adds __GFP_COMP flag to all the location allocating >0 order
pages for the above mentioned meta data. Then their pages are treated
as compound pages now.

Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:32 +02:00
ChangSyun Peng
566cba3c7d md/raid5: Fix Force reconstruct-write io stuck in degraded raid5
commit a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef upstream.

In degraded raid5, we need to read parity to do reconstruct-write when
data disks fail. However, we can not read parity from
handle_stripe_dirtying() in force reconstruct-write mode.

Reproducible Steps:

1. Create degraded raid5
mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 missing
2. Set rmw_level to 0
echo 0 > /sys/block/md2/md/rmw_level
3. IO to raid5

Now some io may be stuck in raid5. We can use handle_stripe_fill() to read
the parity in this situation.

Cc: <stable@vger.kernel.org> # v4.4+
Reviewed-by: Alex Wu <alexwu@synology.com>
Reviewed-by: BingJing Chang <bingjingc@synology.com>
Reviewed-by: Danny Shih <dannyshih@synology.com>
Signed-off-by: ChangSyun Peng <allenpeng@synology.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:32 +02:00
Coly Li
8f2cb3d2e3 bcache: fix super block seq numbers comparision in register_cache_set()
[ 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 <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19 08:14:53 +02:00
Zhao Heming
0bd6a23138 md-cluster: fix wild pointer of unlock_all_bitmaps()
[ 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 <heming.zhao@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19 08:14:51 +02:00
Mikulas Patocka
cab7ef0066 dm integrity: fix integrity recalculation that is improperly skipped
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 <mpatocka redhat com>
Fixes: adc0daad366b ("dm: report suspended device during destroy")
Cc: stable vger kernel org # v4.18+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 10:16:59 +02:00
Mikulas Patocka
35a9af8ddb dm: use noio when sending kobject event
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 <khazhy@google.com>
Reported-by: Tahsin Erdogan <tahsin@google.com>
Reported-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-16 08:17:27 +02:00
Hou Tao
de07529a9a dm zoned: assign max_io_len correctly
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 <houtao1@huawei.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-09 09:37:12 +02:00
Mikulas Patocka
6cd52ae386 dm writecache: add cond_resched to loop in persistent_memory_claim()
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 <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 23:17:19 -04:00
Huaisheng Ye
a33e2d0aa4 dm writecache: correct uncommitted_block when discarding uncommitted entry
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 <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30 23:17:18 -04:00
NeilBrown
f04928c3c2 md: add feature flag MD_FEATURE_RAID0_LAYOUT
[ Upstream commit 33f2c35a54dfd75ad0e7e86918dcbe4de799a56c ]

Due to a bug introduced in Linux 3.14 we cannot determine the
correctly layout for a multi-zone RAID0 array - there are two
possibilities.

It is possible to tell the kernel which to chose using a module
parameter, but this can be clumsy to use.  It would be best if
the choice were recorded in the metadata.
So add a feature flag for this purpose.
If it is set, then the 'layout' field of the superblock is used
to determine which layout to use.

If this flag is not set, then mddev->layout gets set to -1,
which causes the module parameter to be required.

Acked-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25 15:33:10 +02:00
Zhiqiang Liu
2ee8f6e722 bcache: fix potential deadlock problem in btree_gc_coalesce
[ Upstream commit be23e837333a914df3f24bf0b32e87b0331ab8d1 ]

coccicheck reports:
  drivers/md//bcache/btree.c:1538:1-7: preceding lock on line 1417

In btree_gc_coalesce func, if the coalescing process fails, we will goto
to out_nocoalesce tag directly without releasing new_nodes[i]->write_lock.
Then, it will cause a deadlock when trying to acquire new_nodes[i]->
write_lock for freeing new_nodes[i] before return.

btree_gc_coalesce func details as follows:
	if alloc new_nodes[i] fails:
		goto out_nocoalesce;
	// obtain new_nodes[i]->write_lock
	mutex_lock(&new_nodes[i]->write_lock)
	// main coalescing process
	for (i = nodes - 1; i > 0; --i)
		[snipped]
		if coalescing process fails:
			// Here, directly goto out_nocoalesce
			 // tag will cause a deadlock
			goto out_nocoalesce;
		[snipped]
	// release new_nodes[i]->write_lock
	mutex_unlock(&new_nodes[i]->write_lock)
	// coalesing succ, return
	return;
out_nocoalesce:
	btree_node_free(new_nodes[i])	// free new_nodes[i]
	// obtain new_nodes[i]->write_lock
	mutex_lock(&new_nodes[i]->write_lock);
	// set flag for reuse
	clear_bit(BTREE_NODE_dirty, &ew_nodes[i]->flags);
	// release new_nodes[i]->write_lock
	mutex_unlock(&new_nodes[i]->write_lock);

To fix the problem, we add a new tag 'out_unlock_nocoalesce' for
releasing new_nodes[i]->write_lock before out_nocoalesce tag. If
coalescing process fails, we will go to out_unlock_nocoalesce tag
for releasing new_nodes[i]->write_lock before free new_nodes[i] in
out_nocoalesce tag.

(Coly Li helps to clean up commit log format.)

Fixes: 2a285686c109816 ("bcache: btree locking rework")
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25 15:33:06 +02:00
Hannes Reinecke
4ad7add507 dm zoned: return NULL if dmz_get_zone_for_reclaim() fails to find a zone
[ Upstream commit 489dc0f06a5837f87482c0ce61d830d24e17082e ]

The only case where dmz_get_zone_for_reclaim() cannot return a zone is
if the respective lists are empty. So we should just return a simple
NULL value here as we really don't have an error code which would make
sense.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25 15:32:58 +02:00
Martin Wilck
49306a3e9d dm mpath: switch paths in dm_blk_ioctl() code path
[ Upstream commit 2361ae595352dec015d14292f1b539242d8446d6 ]

SCSI LUN passthrough code such as qemu's "scsi-block" device model
pass every IO to the host via SG_IO ioctls. Currently, dm-multipath
calls choose_pgpath() only in the block IO code path, not in the ioctl
code path (unless current_pgpath is NULL). This has the effect that no
path switching and thus no load balancing is done for SCSI-passthrough
IO, unless the active path fails.

Fix this by using the same logic in multipath_prepare_ioctl() as in
multipath_clone_and_map().

Note: The allegedly best path selection algorithm, service-time,
still wouldn't work perfectly, because the io size of the current
request is always set to 0. Changing that for the IO passthrough
case would require the ioctl cmd and arg to be passed to dm's
prepare_ioctl() method.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25 15:32:49 +02:00
Eric Biggers
4c386e2894 dm crypt: avoid truncating the logical block size
commit 64611a15ca9da91ff532982429c44686f4593b5f upstream.

queue_limits::logical_block_size got changed from unsigned short to
unsigned int, but it was forgotten to update crypt_io_hints() to use the
new type.  Fix it.

Fixes: ad6bf88a6c19 ("block: fix an integer overflow in logical block size")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22 09:05:28 +02:00
Coly Li
6358154272 bcache: fix refcount underflow in bcache_device_free()
[ Upstream commit 86da9f736740eba602389908574dfbb0f517baa5 ]

The problematic code piece in bcache_device_free() is,

 785 static void bcache_device_free(struct bcache_device *d)
 786 {
 787     struct gendisk *disk = d->disk;
 [snipped]
 799     if (disk) {
 800             if (disk->flags & GENHD_FL_UP)
 801                     del_gendisk(disk);
 802
 803             if (disk->queue)
 804                     blk_cleanup_queue(disk->queue);
 805
 806             ida_simple_remove(&bcache_device_idx,
 807                               first_minor_to_idx(disk->first_minor));
 808             put_disk(disk);
 809         }
 [snipped]
 816 }

At line 808, put_disk(disk) may encounter kobject refcount of 'disk'
being underflow.

Here is how to reproduce the issue,
- Attche the backing device to a cache device and do random write to
  make the cache being dirty.
- Stop the bcache device while the cache device has dirty data of the
  backing device.
- Only register the backing device back, NOT register cache device.
- The bcache device node /dev/bcache0 won't show up, because backing
  device waits for the cache device shows up for the missing dirty
  data.
- Now echo 1 into /sys/fs/bcache/pendings_cleanup, to stop the pending
  backing device.
- After the pending backing device stopped, use 'dmesg' to check kernel
  message, a use-after-free warning from KASA reported the refcount of
  kobject linked to the 'disk' is underflow.

The dropping refcount at line 808 in the above code piece is added by
add_disk(d->disk) in bch_cached_dev_run(). But in the above condition
the cache device is not registered, bch_cached_dev_run() has no chance
to be called and the refcount is not added. The put_disk() for a non-
added refcount of gendisk kobject triggers a underflow warning.

This patch checks whether GENHD_FL_UP is set in disk->flags, if it is
not set then the bcache device was not added, don't call put_disk()
and the the underflow issue can be avoided.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22 09:05:19 +02:00
Guoqing Jiang
868b8e43a0 md: don't flush workqueue unconditionally in md_open
[ Upstream commit f6766ff6afff70e2aaf39e1511e16d471de7c3ae ]

We need to check mddev->del_work before flush workqueu since the purpose
of flush is to ensure the previous md is disappeared. Otherwise the similar
deadlock appeared if LOCKDEP is enabled, it is due to md_open holds the
bdev->bd_mutex before flush workqueue.

kernel: [  154.522645] ======================================================
kernel: [  154.522647] WARNING: possible circular locking dependency detected
kernel: [  154.522650] 5.6.0-rc7-lp151.27-default #25 Tainted: G           O
kernel: [  154.522651] ------------------------------------------------------
kernel: [  154.522653] mdadm/2482 is trying to acquire lock:
kernel: [  154.522655] ffff888078529128 ((wq_completion)md_misc){+.+.}, at: flush_workqueue+0x84/0x4b0
kernel: [  154.522673]
kernel: [  154.522673] but task is already holding lock:
kernel: [  154.522675] ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522691]
kernel: [  154.522691] which lock already depends on the new lock.
kernel: [  154.522691]
kernel: [  154.522694]
kernel: [  154.522694] the existing dependency chain (in reverse order) is:
kernel: [  154.522696]
kernel: [  154.522696] -> #4 (&bdev->bd_mutex){+.+.}:
kernel: [  154.522704]        __mutex_lock+0x87/0x950
kernel: [  154.522706]        __blkdev_get+0x79/0x590
kernel: [  154.522708]        blkdev_get+0x65/0x140
kernel: [  154.522709]        blkdev_get_by_dev+0x2f/0x40
kernel: [  154.522716]        lock_rdev+0x3d/0x90 [md_mod]
kernel: [  154.522719]        md_import_device+0xd6/0x1b0 [md_mod]
kernel: [  154.522723]        new_dev_store+0x15e/0x210 [md_mod]
kernel: [  154.522728]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522732]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522735]        vfs_write+0xad/0x1a0
kernel: [  154.522737]        ksys_write+0xa4/0xe0
kernel: [  154.522745]        do_syscall_64+0x64/0x2b0
kernel: [  154.522748]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522749]
kernel: [  154.522749] -> #3 (&mddev->reconfig_mutex){+.+.}:
kernel: [  154.522752]        __mutex_lock+0x87/0x950
kernel: [  154.522756]        new_dev_store+0xc9/0x210 [md_mod]
kernel: [  154.522759]        md_attr_store+0x7a/0xc0 [md_mod]
kernel: [  154.522761]        kernfs_fop_write+0x117/0x1b0
kernel: [  154.522763]        vfs_write+0xad/0x1a0
kernel: [  154.522765]        ksys_write+0xa4/0xe0
kernel: [  154.522767]        do_syscall_64+0x64/0x2b0
kernel: [  154.522769]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522770]
kernel: [  154.522770] -> #2 (kn->count#253){++++}:
kernel: [  154.522775]        __kernfs_remove+0x253/0x2c0
kernel: [  154.522778]        kernfs_remove+0x1f/0x30
kernel: [  154.522780]        kobject_del+0x28/0x60
kernel: [  154.522783]        mddev_delayed_delete+0x24/0x30 [md_mod]
kernel: [  154.522786]        process_one_work+0x2a7/0x5f0
kernel: [  154.522788]        worker_thread+0x2d/0x3d0
kernel: [  154.522793]        kthread+0x117/0x130
kernel: [  154.522795]        ret_from_fork+0x3a/0x50
kernel: [  154.522796]
kernel: [  154.522796] -> #1 ((work_completion)(&mddev->del_work)){+.+.}:
kernel: [  154.522800]        process_one_work+0x27e/0x5f0
kernel: [  154.522802]        worker_thread+0x2d/0x3d0
kernel: [  154.522804]        kthread+0x117/0x130
kernel: [  154.522806]        ret_from_fork+0x3a/0x50
kernel: [  154.522807]
kernel: [  154.522807] -> #0 ((wq_completion)md_misc){+.+.}:
kernel: [  154.522813]        __lock_acquire+0x1392/0x1690
kernel: [  154.522816]        lock_acquire+0xb4/0x1a0
kernel: [  154.522818]        flush_workqueue+0xab/0x4b0
kernel: [  154.522821]        md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522823]        __blkdev_get+0xea/0x590
kernel: [  154.522825]        blkdev_get+0x65/0x140
kernel: [  154.522828]        do_dentry_open+0x1d1/0x380
kernel: [  154.522831]        path_openat+0x567/0xcc0
kernel: [  154.522834]        do_filp_open+0x9b/0x110
kernel: [  154.522836]        do_sys_openat2+0x201/0x2a0
kernel: [  154.522838]        do_sys_open+0x57/0x80
kernel: [  154.522840]        do_syscall_64+0x64/0x2b0
kernel: [  154.522842]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522844]
kernel: [  154.522844] other info that might help us debug this:
kernel: [  154.522844]
kernel: [  154.522846] Chain exists of:
kernel: [  154.522846]   (wq_completion)md_misc --> &mddev->reconfig_mutex --> &bdev->bd_mutex
kernel: [  154.522846]
kernel: [  154.522850]  Possible unsafe locking scenario:
kernel: [  154.522850]
kernel: [  154.522852]        CPU0                    CPU1
kernel: [  154.522853]        ----                    ----
kernel: [  154.522854]   lock(&bdev->bd_mutex);
kernel: [  154.522856]                                lock(&mddev->reconfig_mutex);
kernel: [  154.522858]                                lock(&bdev->bd_mutex);
kernel: [  154.522860]   lock((wq_completion)md_misc);
kernel: [  154.522861]
kernel: [  154.522861]  *** DEADLOCK ***
kernel: [  154.522861]
kernel: [  154.522864] 1 lock held by mdadm/2482:
kernel: [  154.522865]  #0: ffff88804efa9338 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x79/0x590
kernel: [  154.522868]
kernel: [  154.522868] stack backtrace:
kernel: [  154.522873] CPU: 1 PID: 2482 Comm: mdadm Tainted: G           O      5.6.0-rc7-lp151.27-default #25
kernel: [  154.522875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
kernel: [  154.522878] Call Trace:
kernel: [  154.522881]  dump_stack+0x8f/0xcb
kernel: [  154.522884]  check_noncircular+0x194/0x1b0
kernel: [  154.522888]  ? __lock_acquire+0x1392/0x1690
kernel: [  154.522890]  __lock_acquire+0x1392/0x1690
kernel: [  154.522893]  lock_acquire+0xb4/0x1a0
kernel: [  154.522895]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522898]  flush_workqueue+0xab/0x4b0
kernel: [  154.522900]  ? flush_workqueue+0x84/0x4b0
kernel: [  154.522905]  ? md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522908]  md_open+0xb6/0xc0 [md_mod]
kernel: [  154.522910]  __blkdev_get+0xea/0x590
kernel: [  154.522912]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522914]  blkdev_get+0x65/0x140
kernel: [  154.522916]  ? bd_acquire+0xc0/0xc0
kernel: [  154.522918]  do_dentry_open+0x1d1/0x380
kernel: [  154.522921]  path_openat+0x567/0xcc0
kernel: [  154.522923]  ? __lock_acquire+0x380/0x1690
kernel: [  154.522926]  do_filp_open+0x9b/0x110
kernel: [  154.522929]  ? __alloc_fd+0xe5/0x1f0
kernel: [  154.522935]  ? kmem_cache_alloc+0x28c/0x630
kernel: [  154.522939]  ? do_sys_openat2+0x201/0x2a0
kernel: [  154.522941]  do_sys_openat2+0x201/0x2a0
kernel: [  154.522944]  do_sys_open+0x57/0x80
kernel: [  154.522946]  do_syscall_64+0x64/0x2b0
kernel: [  154.522948]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
kernel: [  154.522951] RIP: 0033:0x7f98d279d9ae

And md_alloc also flushed the same workqueue, but the thing is different
here. Because all the paths call md_alloc don't hold bdev->bd_mutex, and
the flush is necessary to avoid race condition, so leave it as it is.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22 09:05:17 +02:00
Gabriel Krisman Bertazi
a2cf97eaaa dm multipath: use updated MPATHF_QUEUE_IO on mapping for bio-based mpath
commit 5686dee34dbfe0238c0274e0454fa0174ac0a57a upstream.

When adding devices that don't have a scsi_dh on a BIO based multipath,
I was able to consistently hit the warning below and lock-up the system.

The problem is that __map_bio reads the flag before it potentially being
modified by choose_pgpath, and ends up using the older value.

The WARN_ON below is not trivially linked to the issue. It goes like
this: The activate_path delayed_work is not initialized for non-scsi_dh
devices, but we always set MPATHF_QUEUE_IO, asking for initialization.
That is fine, since MPATHF_QUEUE_IO would be cleared in choose_pgpath.
Nevertheless, only for BIO-based mpath, we cache the flag before calling
choose_pgpath, and use the older version when deciding if we should
initialize the path.  Therefore, we end up trying to initialize the
paths, and calling the non-initialized activate_path work.

[   82.437100] ------------[ cut here ]------------
[   82.437659] WARNING: CPU: 3 PID: 602 at kernel/workqueue.c:1624
  __queue_delayed_work+0x71/0x90
[   82.438436] Modules linked in:
[   82.438911] CPU: 3 PID: 602 Comm: systemd-udevd Not tainted 5.6.0-rc6+ #339
[   82.439680] RIP: 0010:__queue_delayed_work+0x71/0x90
[   82.440287] Code: c1 48 89 4a 50 81 ff 00 02 00 00 75 2a 4c 89 cf e9
94 d6 07 00 e9 7f e9 ff ff 0f 0b eb c7 0f 0b 48 81 7a 58 40 74 a8 94 74
a7 <0f> 0b 48 83 7a 48 00 74 a5 0f 0b eb a1 89 fe 4c 89 cf e9 c8 c4 07
[   82.441719] RSP: 0018:ffffb738803977c0 EFLAGS: 00010007
[   82.442121] RAX: ffffa086389f9740 RBX: 0000000000000002 RCX: 0000000000000000
[   82.442718] RDX: ffffa086350dd930 RSI: ffffa0863d76f600 RDI: 0000000000000200
[   82.443484] RBP: 0000000000000200 R08: 0000000000000000 R09: ffffa086350dd970
[   82.444128] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa086350dd930
[   82.444773] R13: ffffa0863d76f600 R14: 0000000000000000 R15: ffffa08636738008
[   82.445427] FS:  00007f6abfe9dd40(0000) GS:ffffa0863dd80000(0000) knlGS:00000
[   82.446040] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   82.446478] CR2: 0000557d288db4e8 CR3: 0000000078b36000 CR4: 00000000000006e0
[   82.447104] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   82.447561] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   82.448012] Call Trace:
[   82.448164]  queue_delayed_work_on+0x6d/0x80
[   82.448472]  __pg_init_all_paths+0x7b/0xf0
[   82.448714]  pg_init_all_paths+0x26/0x40
[   82.448980]  __multipath_map_bio.isra.0+0x84/0x210
[   82.449267]  __map_bio+0x3c/0x1f0
[   82.449468]  __split_and_process_non_flush+0x14a/0x1b0
[   82.449775]  __split_and_process_bio+0xde/0x340
[   82.450045]  ? dm_get_live_table+0x5/0xb0
[   82.450278]  dm_process_bio+0x98/0x290
[   82.450518]  dm_make_request+0x54/0x120
[   82.450778]  generic_make_request+0xd2/0x3e0
[   82.451038]  ? submit_bio+0x3c/0x150
[   82.451278]  submit_bio+0x3c/0x150
[   82.451492]  mpage_readpages+0x129/0x160
[   82.451756]  ? bdev_evict_inode+0x1d0/0x1d0
[   82.452033]  read_pages+0x72/0x170
[   82.452260]  __do_page_cache_readahead+0x1ba/0x1d0
[   82.452624]  force_page_cache_readahead+0x96/0x110
[   82.452903]  generic_file_read_iter+0x84f/0xae0
[   82.453192]  ? __seccomp_filter+0x7c/0x670
[   82.453547]  new_sync_read+0x10e/0x190
[   82.453883]  vfs_read+0x9d/0x150
[   82.454172]  ksys_read+0x65/0xe0
[   82.454466]  do_syscall_64+0x4e/0x210
[   82.454828]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[...]
[   82.462501] ---[ end trace bb39975e9cf45daa ]---

Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-06 08:13:29 +02:00
Mikulas Patocka
7889936a92 dm writecache: fix data corruption when reloading the target
commit 31b22120194b5c0d460f59e0c98504de1d3f1f14 upstream.

The dm-writecache reads metadata in the target constructor. However, when
we reload the target, there could be another active instance running on
the same device. This is the sequence of operations when doing a reload:

1. construct new target
2. suspend old target
3. resume new target
4. destroy old target

Metadata that were written by the old target between steps 1 and 2 would
not be visible by the new target.

Fix the data corruption by loading the metadata in the resume handler.

Also, validate block_size is at least as large as both the devices'
logical block size and only read 1 block from the metadata during
target constructor -- no need to read entirety of metadata now that it
is done during resume.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-06 08:13:28 +02:00
Sunwook Eom
d4440a7780 dm verity fec: fix hash block number in verity_fec_decode
commit ad4e80a639fc61d5ecebb03caa5cdbfb91fcebfc upstream.

The error correction data is computed as if data and hash blocks
were concatenated. But hash block number starts from v->hash_start.
So, we have to calculate hash block number based on that.

Fixes: a739ff3f543af ("dm verity: add support for forward error correction")
Cc: stable@vger.kernel.org
Signed-off-by: Sunwook Eom <speed.eom@samsung.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-06 08:13:28 +02:00
Bob Liu
738d853b16 dm zoned: remove duplicate nr_rnd_zones increase in dmz_init_zone()
[ Upstream commit b8fdd090376a7a46d17db316638fe54b965c2fb0 ]

zmd->nr_rnd_zones was increased twice by mistake. The other place it
is increased in dmz_init_zone() is the only one needed:

1131                 zmd->nr_useable_zones++;
1132                 if (dmz_is_rnd(zone)) {
1133                         zmd->nr_rnd_zones++;
					^^^
Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17 10:48:54 +02:00
Shetty, Harshini X (EXT-Sony Mobile)
9276066747 dm verity fec: fix memory leak in verity_fec_dtr
commit 75fa601934fda23d2f15bf44b09c2401942d8e15 upstream.

Fix below kmemleak detected in verity_fec_ctr. output_pool is
allocated for each dm-verity-fec device. But it is not freed when
dm-table for the verity target is removed. Hence free the output
mempool in destructor function verity_fec_dtr.

unreferenced object 0xffffffffa574d000 (size 4096):
  comm "init", pid 1667, jiffies 4294894890 (age 307.168s)
  hex dump (first 32 bytes):
    8e 36 00 98 66 a8 0b 9b 00 00 00 00 00 00 00 00  .6..f...........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000060e82407>] __kmalloc+0x2b4/0x340
    [<00000000dd99488f>] mempool_kmalloc+0x18/0x20
    [<000000002560172b>] mempool_init_node+0x98/0x118
    [<000000006c3574d2>] mempool_init+0x14/0x20
    [<0000000008cb266e>] verity_fec_ctr+0x388/0x3b0
    [<000000000887261b>] verity_ctr+0x87c/0x8d0
    [<000000002b1e1c62>] dm_table_add_target+0x174/0x348
    [<000000002ad89eda>] table_load+0xe4/0x328
    [<000000001f06f5e9>] dm_ctl_ioctl+0x3b4/0x5a0
    [<00000000bee5fbb7>] do_vfs_ioctl+0x5dc/0x928
    [<00000000b475b8f5>] __arm64_sys_ioctl+0x70/0x98
    [<000000005361e2e8>] el0_svc_common+0xa0/0x158
    [<000000001374818f>] el0_svc_handler+0x6c/0x88
    [<000000003364e9f4>] el0_svc+0x8/0xc
    [<000000009d84cec9>] 0xffffffffffffffff

Fixes: a739ff3f543af ("dm verity: add support for forward error correction")
Depends-on: 6f1c819c219f7 ("dm: convert to bioset_init()/mempool_init()")
Cc: stable@vger.kernel.org
Signed-off-by: Harshini Shetty <harshini.x.shetty@sony.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:48:50 +02:00
Mikulas Patocka
6f3a303a34 dm writecache: add cond_resched to avoid CPU hangs
commit 1edaa447d958bec24c6a79685a5790d98976fd16 upstream.

Initializing a dm-writecache device can take a long time when the
persistent memory device is large.  Add cond_resched() to a few loops
to avoid warnings that the CPU is stuck.

Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:48:50 +02:00
Guoqing Jiang
41778458da md: check arrays is suspended in mddev_detach before call quiesce operations
[ Upstream commit 6b40bec3b13278d21fa6c1ae7a0bdf2e550eed5f ]

Don't call quiesce(1) and quiesce(0) if array is already suspended,
otherwise in level_store, the array is writable after mddev_detach
in below part though the intention is to make array writable after
resume.

	mddev_suspend(mddev);
	mddev_detach(mddev);
	...
	mddev_resume(mddev);

And it also causes calltrace as follows in [1].

[48005.653834] WARNING: CPU: 1 PID: 45380 at kernel/kthread.c:510 kthread_park+0x77/0x90
[...]
[48005.653976] CPU: 1 PID: 45380 Comm: mdadm Tainted: G           OE     5.4.10-arch1-1 #1
[48005.653979] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4105-ITX, BIOS P1.40 08/06/2018
[48005.653984] RIP: 0010:kthread_park+0x77/0x90
[48005.654015] Call Trace:
[48005.654039]  r5l_quiesce+0x3c/0x70 [raid456]
[48005.654052]  raid5_quiesce+0x228/0x2e0 [raid456]
[48005.654073]  mddev_detach+0x30/0x70 [md_mod]
[48005.654090]  level_store+0x202/0x670 [md_mod]
[48005.654099]  ? security_capable+0x40/0x60
[48005.654114]  md_attr_store+0x7b/0xc0 [md_mod]
[48005.654123]  kernfs_fop_write+0xce/0x1b0
[48005.654132]  vfs_write+0xb6/0x1a0
[48005.654138]  ksys_write+0x67/0xe0
[48005.654146]  do_syscall_64+0x4e/0x140
[48005.654155]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[48005.654161] RIP: 0033:0x7fa0c8737497

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=206161

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17 10:48:42 +02:00
Mike Snitzer
1ea3bdf9e9 dm integrity: use dm_bio_record and dm_bio_restore
[ Upstream commit 248aa2645aa7fc9175d1107c2593cc90d4af5a4e ]

In cases where dec_in_flight() has to requeue the integrity_bio_wait
work to transfer the rest of the data, the bio's __bi_remaining might
already have been decremented to 0, e.g.: if bio passed to underlying
data device was split via blk_queue_split().

Use dm_bio_{record,restore} rather than effectively open-coding them in
dm-integrity -- these methods now manage __bi_remaining too.

Depends-on: f7f0b057a9c1 ("dm bio record: save/restore bi_end_io and bi_integrity")
Reported-by: Daniel Glöckner <dg@emlix.com>
Suggested-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25 08:06:07 +01:00
Mike Snitzer
da23154ff0 dm bio record: save/restore bi_end_io and bi_integrity
[ Upstream commit 1b17159e52bb31f982f82a6278acd7fab1d3f67b ]

Also, save/restore __bi_remaining in case the bio was used in a
BIO_CHAIN (e.g. due to blk_queue_split).

Suggested-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25 08:06:07 +01:00
Mikulas Patocka
bd68d2206b dm integrity: fix a deadlock due to offloading to an incorrect workqueue
commit 53770f0ec5fd417429775ba006bc4abe14002335 upstream.

If we need to perform synchronous I/O in dm_integrity_map_continue(),
we must make sure that we are not in the map function - in order to
avoid the deadlock due to bio queuing in generic_make_request. To
avoid the deadlock, we offload the request to metadata_wq.

However, metadata_wq also processes metadata updates for write requests.
If there are too many requests that get offloaded to metadata_wq at the
beginning of dm_integrity_map_continue, the workqueue metadata_wq
becomes clogged and the system is incapable of processing any metadata
updates.

This causes a deadlock because all the requests that need to do metadata
updates wait for metadata_wq to proceed and metadata_wq waits inside
wait_and_add_new_range until some existing request releases its range
lock (which doesn't happen because the range lock is released after
metadata update).

In order to fix the deadlock, we create a new workqueue offload_wq and
offload requests to it - so that processing of offload_wq is independent
from processing of metadata_wq.

Fixes: 7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org # v4.12+
Reported-by: Heinz Mauelshagen <heinzm@redhat.com>
Tested-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11 14:15:13 +01:00
Mikulas Patocka
0e242863c5 dm writecache: verify watermark during resume
commit 41c526c5af46d4c4dab7f72c99000b7fac0b9702 upstream.

Verify the watermark upon resume - so that if the target is reloaded
with lower watermark, it will start the cleanup process immediately.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11 14:15:06 +01:00
Mikulas Patocka
98423303b0 dm: report suspended device during destroy
commit adc0daad366b62ca1bce3e2958a40b0b71a8b8b3 upstream.

The function dm_suspended returns true if the target is suspended.
However, when the target is being suspended during unload, it returns
false.

An example where this is a problem: the test "!dm_suspended(wc->ti)" in
writecache_writeback is not sufficient, because dm_suspended returns
zero while writecache_suspend is in progress.  As is, without an
enhanced dm_suspended, simply switching from flush_workqueue to
drain_workqueue still emits warnings:
workqueue writecache-writeback: drain_workqueue() isn't complete after 10 tries
workqueue writecache-writeback: drain_workqueue() isn't complete after 100 tries
workqueue writecache-writeback: drain_workqueue() isn't complete after 200 tries
workqueue writecache-writeback: drain_workqueue() isn't complete after 300 tries
workqueue writecache-writeback: drain_workqueue() isn't complete after 400 tries

writecache_suspend calls flush_workqueue(wc->writeback_wq) - this function
flushes the current work. However, the workqueue may re-queue itself and
flush_workqueue doesn't wait for re-queued works to finish. Because of
this - the function writecache_writeback continues execution after the
device was suspended and then concurrently with writecache_dtr, causing
a crash in writecache_writeback.

We must use drain_workqueue - that waits until the work and all re-queued
works finish.

As a prereq for switching to drain_workqueue, this commit fixes
dm_suspended to return true after the presuspend hook and before the
postsuspend hook - just like during a normal suspend. It allows
simplifying the dm-integrity and dm-writecache targets so that they
don't have to maintain suspended flags on their own.

With this change use of drain_workqueue() can be used effectively.  This
change was tested with the lvm2 testsuite and cryptsetup testsuite and
the are no regressions.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Reported-by: Corey Marthaler <cmarthal@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11 14:15:05 +01:00
Mikulas Patocka
bc21bbf6b4 dm cache: fix a crash due to incorrect work item cancelling
commit 7cdf6a0aae1cccf5167f3f04ecddcf648b78e289 upstream.

The crash can be reproduced by running the lvm2 testsuite test
lvconvert-thin-external-cache.sh for several minutes, e.g.:
  while :; do make check T=shell/lvconvert-thin-external-cache.sh; done

The crash happens in this call chain:
do_waker -> policy_tick -> smq_tick -> end_hotspot_period -> clear_bitset
-> memset -> __memset -- which accesses an invalid pointer in the vmalloc
area.

The work entry on the workqueue is executed even after the bitmap was
freed. The problem is that cancel_delayed_work doesn't wait for the
running work item to finish, so the work item can continue running and
re-submitting itself even after cache_postsuspend. In order to make sure
that the work item won't be running, we must use cancel_delayed_work_sync.

Also, change flush_workqueue to drain_workqueue, so that if some work item
submits itself or another work item, we are properly waiting for both of
them.

Fixes: c6b4fcbad044 ("dm: add cache target")
Cc: stable@vger.kernel.org # v3.9
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11 14:15:05 +01:00
Coly Li
5a5649a421 bcache: explicity type cast in bset_bkey_last()
[ Upstream commit 7c02b0055f774ed9afb6e1c7724f33bf148ffdc0 ]

In bset.h, macro bset_bkey_last() is defined as,
    bkey_idx((struct bkey *) (i)->d, (i)->keys)

Parameter i can be variable type of data structure, the macro always
works once the type of struct i has member 'd' and 'keys'.

bset_bkey_last() is also used in macro csum_set() to calculate the
checksum of a on-disk data structure. When csum_set() is used to
calculate checksum of on-disk bcache super block, the parameter 'i'
data type is struct cache_sb_disk. Inside struct cache_sb_disk (also in
struct cache_sb) the member keys is __u16 type. But bkey_idx() expects
unsigned int (a 32bit width), so there is problem when sending
parameters via stack to call bkey_idx().

Sparse tool from Intel 0day kbuild system reports this incompatible
problem. bkey_idx() is part of user space API, so the simplest fix is
to cast the (i)->keys to unsigned int type in macro bset_bkey_last().

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:34:53 +01:00
Liang Chen
4fdf57e5dd bcache: cached_dev_free needs to put the sb page
[ Upstream commit e8547d42095e58bee658f00fef8e33d2a185c927 ]

Same as cache device, the buffer page needs to be put while
freeing cached_dev.  Otherwise a page would be leaked every
time a cached_dev is stopped.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:34:51 +01:00
Coly Li
e608cd92ba bcache: add readahead cache policy options via sysfs interface
commit 038ba8cc1bffc51250add4a9b9249d4331576d8f upstream.

In year 2007 high performance SSD was still expensive, in order to
save more space for real workload or meta data, the readahead I/Os
for non-meta data was bypassed and not cached on SSD.

In now days, SSD price drops a lot and people can find larger size
SSD with more comfortable price. It is unncessary to alway bypass
normal readahead I/Os to save SSD space for now.

This patch adds options for readahead data cache policies via sysfs
file /sys/block/bcache<N>/readahead_cache_policy, the options are,
- "all": cache all readahead data I/Os.
- "meta-only": only cache meta data, and bypass other regular I/Os.

If users want to make bcache continue to only cache readahead request
for metadata and bypass regular data readahead, please set "meta-only"
to this sysfs file. By default, bcache will back to cache all read-
ahead requests now.

Cc: stable@vger.kernel.org
Signed-off-by: Coly Li <colyli@suse.de>
Acked-by: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:08 -08:00
Mikulas Patocka
a999296636 dm writecache: fix incorrect flush sequence when doing SSD mode commit
commit aa9509209c5ac2f0b35d01a922bf9ae072d0c2fc upstream.

When committing state, the function writecache_flush does the following:
1. write metadata (writecache_commit_flushed)
2. flush disk cache (writecache_commit_flushed)
3. wait for data writes to complete (writecache_wait_for_ios)
4. increase superblock seq_count
5. write the superblock
6. flush disk cache

It may happen that at step 3, when we wait for some write to finish, the
disk may report the write as finished, but the write only hit the disk
cache and it is not yet stored in persistent storage. At step 5 we write
the superblock - it may happen that the superblock is written before the
write that we waited for in step 3. If the machine crashes, it may result
in incorrect data being returned after reboot.

In order to fix the bug, we must swap steps 2 and 3 in the above sequence,
so that we first wait for writes to complete and then flush the disk
cache.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:04 -08:00
Mike Snitzer
9eb75d69e9 dm: fix potential for q->make_request_fn NULL pointer
commit 47ace7e012b9f7ad71d43ac9063d335ea3d6820b upstream.

Move blk_queue_make_request() to dm.c:alloc_dev() so that
q->make_request_fn is never NULL during the lifetime of a DM device
(even one that is created without a DM table).

Otherwise generic_make_request() will crash simply by doing:
  dmsetup create -n test
  mount /dev/dm-N /mnt

While at it, move ->congested_data initialization out of
dm.c:alloc_dev() and into the bio-based specific init method.

Reported-by: Stefan Bader <stefan.bader@canonical.com>
BugLink: https://bugs.launchpad.net/bugs/1860231
Fixes: ff36ab34583a ("dm: remove request-based logic from make_request_fn wrapper")
Depends-on: c12c9a3c3860c ("dm: various cleanups to md->queue initialization code")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:04 -08:00
Milan Broz
607d7cf285 dm crypt: fix benbi IV constructor crash if used in authenticated mode
commit 4ea9471fbd1addb25a4d269991dc724e200ca5b5 upstream.

If benbi IV is used in AEAD construction, for example:
  cryptsetup luksFormat <device> --cipher twofish-xts-benbi --key-size 512 --integrity=hmac-sha256
the constructor uses wrong skcipher function and crashes:

 BUG: kernel NULL pointer dereference, address: 00000014
 ...
 EIP: crypt_iv_benbi_ctr+0x15/0x70 [dm_crypt]
 Call Trace:
  ? crypt_subkey_size+0x20/0x20 [dm_crypt]
  crypt_ctr+0x567/0xfc0 [dm_crypt]
  dm_table_add_target+0x15f/0x340 [dm_mod]

Fix this by properly using crypt_aead_blocksize() in this case.

Fixes: ef43aa38063a6 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # v4.12+
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=941051
Reported-by: Jerad Simpson <jbsimpson@gmail.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:04 -08:00
Joe Thornber
1fac9f574c dm space map common: fix to ensure new block isn't already in use
commit 4feaef830de7ffdd8352e1fe14ad3bf13c9688f8 upstream.

The space-maps track the reference counts for disk blocks allocated by
both the thin-provisioning and cache targets.  There are variants for
tracking metadata blocks and data blocks.

Transactionality is implemented by never touching blocks from the
previous transaction, so we can rollback in the event of a crash.

When allocating a new block we need to ensure the block is free (has
reference count of 0) in both the current and previous transaction.
Prior to this fix we were doing this by searching for a free block in
the previous transaction, and relying on a 'begin' counter to track
where the last allocation in the current transaction was.  This
'begin' field was not being updated in all code paths (eg, increment
of a data block reference count due to breaking sharing of a neighbour
block in the same btree leaf).

This fix keeps the 'begin' field, but now it's just a hint to speed up
the search.  Instead the current transaction is searched for a free
block, and then the old transaction is double checked to ensure it's
free.  Much simpler.

This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when
DM thin-provisioning's snapshots are heavily used.

Reported-by: Eric Wheeler <dm-devel@lists.ewheeler.net>
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:03 -08:00
Dmitry Fomichev
4ae8d3a5f3 dm zoned: support zone sizes smaller than 128MiB
commit b39962950339912978484cdac50069258545d753 upstream.

dm-zoned is observed to log failed kernel assertions and not work
correctly when operating against a device with a zone size smaller
than 128MiB (e.g. 32768 bits per 4K block). The reason is that the
bitmap size per zone is calculated as zero with such a small zone
size. Fix this problem and also make the code related to zone bitmap
management be able to handle per zone bitmaps smaller than a single
block.

A dm-zoned-tools patch is required to properly format dm-zoned devices
with zone sizes smaller than 128MiB.

Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:34:03 -08:00
Dan Carpenter
e7728e18a7 bcache: Fix an error code in bch_dump_read()
[ Upstream commit d66c9920c0cf984cf99cab5036fd5f3a1b7fba46 ]

The copy_to_user() function returns the number of bytes remaining to be
copied, but the intention here was to return -EFAULT if the copy fails.

Fixes: cafe56359144 ("bcache: A block layer cache")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27 14:51:09 +01:00
Mikulas Patocka
a7f79052d1 block: fix an integer overflow in logical block size
commit ad6bf88a6c19a39fb3b0045d78ea880325dfcf15 upstream.

Logical block size has type unsigned short. That means that it can be at
most 32768. However, there are architectures that can run with 64k pages
(for example arm64) and on these architectures, it may be possible to
create block devices with 64k block size.

For exmaple (run this on an architecture with 64k pages):

Mount will fail with this error because it tries to read the superblock using 2-sector
access:
  device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536
  EXT4-fs (dm-0): unable to read superblock

This patch changes the logical block size from unsigned short to unsigned
int to avoid the overflow.

Cc: stable@vger.kernel.org
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:21:29 +01:00
Zhiqiang Liu
ec322d9884 md: raid1: check rdev before reference in raid1_sync_request func
[ Upstream commit 028288df635f5a9addd48ac4677b720192747944 ]

In raid1_sync_request func, rdev should be checked before reference.

Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09 10:18:57 +01:00
Coly Li
247acf4308 bcache: at least try to shrink 1 node in bch_mca_scan()
[ Upstream commit 9fcc34b1a6dd4b8e5337e2b6ef45e428897eca6b ]

In bch_mca_scan(), the number of shrinking btree node is calculated
by code like this,
	unsigned long nr = sc->nr_to_scan;

        nr /= c->btree_pages;
        nr = min_t(unsigned long, nr, mca_can_free(c));
variable sc->nr_to_scan is number of objects (here is bcache B+tree
nodes' number) to shrink, and pointer variable sc is sent from memory
management code as parametr of a callback.

If sc->nr_to_scan is smaller than c->btree_pages, after the above
calculation, variable 'nr' will be 0 and nothing will be shrunk. It is
frequeently observed that only 1 or 2 is set to sc->nr_to_scan and make
nr to be zero. Then bch_mca_scan() will do nothing more then acquiring
and releasing mutex c->bucket_lock.

This patch checkes whether nr is 0 after the above calculation, if 0
is the result then set 1 to variable 'n'. Then at least bch_mca_scan()
will try to shrink a single B+tree node.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04 19:12:58 +01:00
Andrea Righi
c2437d0770 bcache: fix deadlock in bcache_allocator
[ Upstream commit 84c529aea182939e68f618ed9813740c9165c7eb ]

bcache_allocator can call the following:

 bch_allocator_thread()
  -> bch_prio_write()
     -> bch_bucket_alloc()
        -> wait on &ca->set->bucket_wait

But the wake up event on bucket_wait is supposed to come from
bch_allocator_thread() itself => deadlock:

[ 1158.490744] INFO: task bcache_allocato:15861 blocked for more than 10 seconds.
[ 1158.495929]       Not tainted 5.3.0-050300rc3-generic #201908042232
[ 1158.500653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1158.504413] bcache_allocato D    0 15861      2 0x80004000
[ 1158.504419] Call Trace:
[ 1158.504429]  __schedule+0x2a8/0x670
[ 1158.504432]  schedule+0x2d/0x90
[ 1158.504448]  bch_bucket_alloc+0xe5/0x370 [bcache]
[ 1158.504453]  ? wait_woken+0x80/0x80
[ 1158.504466]  bch_prio_write+0x1dc/0x390 [bcache]
[ 1158.504476]  bch_allocator_thread+0x233/0x490 [bcache]
[ 1158.504491]  kthread+0x121/0x140
[ 1158.504503]  ? invalidate_buckets+0x890/0x890 [bcache]
[ 1158.504506]  ? kthread_park+0xb0/0xb0
[ 1158.504510]  ret_from_fork+0x35/0x40

Fix by making the call to bch_prio_write() non-blocking, so that
bch_allocator_thread() never waits on itself.

Moreover, make sure to wake up the garbage collector thread when
bch_prio_write() is failing to allocate buckets.

BugLink: https://bugs.launchpad.net/bugs/1784665
BugLink: https://bugs.launchpad.net/bugs/1796292
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:36:02 +01:00
Coly Li
815f43441d bcache: fix static checker warning in bcache_device_free()
[ Upstream commit 2d8869518a525c9bce5f5268419df9dfbe3dfdeb ]

Commit cafe56359144 ("bcache: A block layer cache") leads to the
following static checker warning:

    ./drivers/md/bcache/super.c:770 bcache_device_free()
    warn: variable dereferenced before check 'd->disk' (see line 766)

drivers/md/bcache/super.c
   762  static void bcache_device_free(struct bcache_device *d)
   763  {
   764          lockdep_assert_held(&bch_register_lock);
   765
   766          pr_info("%s stopped", d->disk->disk_name);
                                      ^^^^^^^^^
Unchecked dereference.

   767
   768          if (d->c)
   769                  bcache_device_detach(d);
   770          if (d->disk && d->disk->flags & GENHD_FL_UP)
                    ^^^^^^^
Check too late.

   771                  del_gendisk(d->disk);
   772          if (d->disk && d->disk->queue)
   773                  blk_cleanup_queue(d->disk->queue);
   774          if (d->disk) {
   775                  ida_simple_remove(&bcache_device_idx,
   776                                    first_minor_to_idx(d->disk->first_minor));
   777                  put_disk(d->disk);
   778          }
   779

It is not 100% sure that the gendisk struct of bcache device will always
be there, the warning makes sense when there is problem in block core.

This patch tries to remove the static checking warning by checking
d->disk to avoid NULL pointer deferences.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:36:01 +01:00
Guoqing Jiang
5d8a64e6f2 md/bitmap: avoid race window between md_bitmap_resize and bitmap_file_clear_bit
[ Upstream commit fadcbd2901a0f7c8721f3bdb69eac95c272dc8ed ]

We need to move "spin_lock_irq(&bitmap->counts.lock)" before unmap previous
storage, otherwise panic like belows could happen as follows.

[  902.353802] sdl: detected capacity change from 1077936128 to 3221225472
[  902.616948] general protection fault: 0000 [#1] SMP
[snip]
[  902.618588] CPU: 12 PID: 33698 Comm: md0_raid1 Tainted: G           O    4.14.144-1-pserver #4.14.144-1.1~deb10
[  902.618870] Hardware name: Supermicro SBA-7142G-T4/BHQGE, BIOS 3.00       10/24/2012
[  902.619120] task: ffff9ae1860fc600 task.stack: ffffb52e4c704000
[  902.619301] RIP: 0010:bitmap_file_clear_bit+0x90/0xd0 [md_mod]
[  902.619464] RSP: 0018:ffffb52e4c707d28 EFLAGS: 00010087
[  902.619626] RAX: ffe8008b0d061000 RBX: ffff9ad078c87300 RCX: 0000000000000000
[  902.619792] RDX: ffff9ad986341868 RSI: 0000000000000803 RDI: ffff9ad078c87300
[  902.619986] RBP: ffff9ad0ed7a8000 R08: 0000000000000000 R09: 0000000000000000
[  902.620154] R10: ffffb52e4c707ec0 R11: ffff9ad987d1ed44 R12: ffff9ad0ed7a8360
[  902.620320] R13: 0000000000000003 R14: 0000000000060000 R15: 0000000000000800
[  902.620487] FS:  0000000000000000(0000) GS:ffff9ad987d00000(0000) knlGS:0000000000000000
[  902.620738] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  902.620901] CR2: 000055ff12aecec0 CR3: 0000001005207000 CR4: 00000000000406e0
[  902.621068] Call Trace:
[  902.621256]  bitmap_daemon_work+0x2dd/0x360 [md_mod]
[  902.621429]  ? find_pers+0x70/0x70 [md_mod]
[  902.621597]  md_check_recovery+0x51/0x540 [md_mod]
[  902.621762]  raid1d+0x5c/0xeb0 [raid1]
[  902.621939]  ? try_to_del_timer_sync+0x4d/0x80
[  902.622102]  ? del_timer_sync+0x35/0x40
[  902.622265]  ? schedule_timeout+0x177/0x360
[  902.622453]  ? call_timer_fn+0x130/0x130
[  902.622623]  ? find_pers+0x70/0x70 [md_mod]
[  902.622794]  ? md_thread+0x94/0x150 [md_mod]
[  902.622959]  md_thread+0x94/0x150 [md_mod]
[  902.623121]  ? wait_woken+0x80/0x80
[  902.623280]  kthread+0x119/0x130
[  902.623437]  ? kthread_create_on_node+0x60/0x60
[  902.623600]  ret_from_fork+0x22/0x40
[  902.624225] RIP: bitmap_file_clear_bit+0x90/0xd0 [md_mod] RSP: ffffb52e4c707d28

Because mdadm was running on another cpu to do resize, so bitmap_resize was
called to replace bitmap as below shows.

PID: 38801  TASK: ffff9ad074a90e00  CPU: 0   COMMAND: "mdadm"
   [exception RIP: queued_spin_lock_slowpath+56]
   [snip]
-- <NMI exception stack> --
 #5 [ffffb52e60f17c58] queued_spin_lock_slowpath at ffffffff9c0b27b8
 #6 [ffffb52e60f17c58] bitmap_resize at ffffffffc0399877 [md_mod]
 #7 [ffffb52e60f17d30] raid1_resize at ffffffffc0285bf9 [raid1]
 #8 [ffffb52e60f17d50] update_size at ffffffffc038a31a [md_mod]
 #9 [ffffb52e60f17d70] md_ioctl at ffffffffc0395ca4 [md_mod]

And the procedure to keep resize bitmap safe is allocate new storage
space, then quiesce, copy bits, replace bitmap, and re-start.

However the daemon (bitmap_daemon_work) could happen even the array is
quiesced, which means when bitmap_file_clear_bit is triggered by raid1d,
then it thinks it should be fine to access store->filemap since
counts->lock is held, but resize could change the storage without the
protection of the lock.

Cc: Jack Wang <jinpu.wang@cloud.ionos.com>
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:35:25 +01:00
Hou Tao
6970c15923 dm btree: increase rebalance threshold in __rebalance2()
commit 474e559567fa631dea8fb8407ab1b6090c903755 upstream.

We got the following warnings from thin_check during thin-pool setup:

  $ thin_check /dev/vdb
  examining superblock
  examining devices tree
    missing devices: [1, 84]
      too few entries in btree_node: 41, expected at least 42 (block 138, max_entries = 126)
  examining mapping tree

The phenomenon is the number of entries in one node of details_info tree is
less than (max_entries / 3). And it can be easily reproduced by the following
procedures:

  $ new a thin pool
  $ presume the max entries of details_info tree is 126
  $ new 127 thin devices (e.g. 1~127) to make the root node being full
    and then split
  $ remove the first 43 (e.g. 1~43) thin devices to make the children
    reblance repeatedly
  $ stop the thin pool
  $ thin_check

The root cause is that the B-tree removal procedure in __rebalance2()
doesn't guarantee the invariance: the minimal number of entries in
non-root node should be >= (max_entries / 3).

Simply fix the problem by increasing the rebalance threshold to
make sure the number of entries in each child will be greater
than or equal to (max_entries / 3 + 1), so no matter which
child is used for removal, the number will still be valid.

Cc: stable@vger.kernel.org
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21 10:57:41 +01:00