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Mike Snitzer e16b302f69 dm thin: fix use-after-free in metadata_pre_commit_callback
[ Upstream commit a4a8d28658 ]

dm-thin uses struct pool to hold the state of the pool. There may be
multiple pool_c's pointing to a given pool, each pool_c represents a
loaded target. pool_c's may be created and destroyed arbitrarily and the
pool contains a reference count of pool_c's pointing to it.

Since commit 694cfe7f31 ("dm thin: Flush data device before
committing metadata") a pointer to pool_c is passed to
dm_pool_register_pre_commit_callback and this function stores it in
pmd->pre_commit_context. If this pool_c is freed, but pool is not
(because there is another pool_c referencing it), we end up in a
situation where pmd->pre_commit_context structure points to freed
pool_c. It causes a crash in metadata_pre_commit_callback.

Fix this by moving the dm_pool_register_pre_commit_callback() from
pool_ctr() to pool_preresume(). This way the in-core thin-pool metadata
is only ever armed with callback data whose lifetime matches the
active thin-pool target.

In should be noted that this fix preserves the ability to load a
thin-pool table that uses a different data block device (that contains
the same data) -- though it is unclear if that capability is still
useful and/or needed.

Fixes: 694cfe7f31 ("dm thin: Flush data device before committing metadata")
Cc: stable@vger.kernel.org
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-05 21:22:53 +00:00
Mikulas Patocka 6eed26e35c block: fix an integer overflow in logical block size
commit ad6bf88a6c 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 08:22:32 +01:00
Zhiqiang Liu 25432fa3ac md: raid1: check rdev before reference in raid1_sync_request func
[ Upstream commit 028288df63 ]

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 10:19:48 +01:00
Guoqing Jiang aae93615aa raid5: need to set STRIPE_HANDLE for batch head
[ Upstream commit a7ede3d168 ]

With commit 6ce220dd2f ("raid5: don't set
STRIPE_HANDLE to stripe which is in batch list"), we don't want to set
STRIPE_HANDLE flag for sh which is already in batch list.

However, the stripe which is the head of batch list should set this flag,
otherwise panic could happen inside init_stripe at BUG_ON(sh->batch_head),
it is reproducible with raid5 on top of nvdimm devices per Xiao oberserved.

Thanks for Xiao's effort to verify the change.

Fixes: 6ce220dd2f ("raid5: don't set STRIPE_HANDLE to stripe which is in batch list")
Reported-by: Xiao Ni <xni@redhat.com>
Tested-by: Xiao Ni <xni@redhat.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>
2020-01-09 10:19:48 +01:00
Yufen Yu 33ecb96148 md: make sure desc_nr less than MD_SB_DISKS
[ Upstream commit 3b7436cc94 ]

For super_90_load, we need to make sure 'desc_nr' less
than MD_SB_DISKS, avoiding invalid memory access of 'sb->disks'.

Fixes: 228fc7d76d ("md: avoid invalid memory access for array sb->dev_roles")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04 19:18:34 +01:00
Coly Li 9120405973 bcache: at least try to shrink 1 node in bch_mca_scan()
[ Upstream commit 9fcc34b1a6 ]

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 19:18:11 +01:00
Yufen Yu 9e3175ea23 md: avoid invalid memory access for array sb->dev_roles
[ Upstream commit 228fc7d76d ]

we need to gurantee 'desc_nr' valid before access array
of sb->dev_roles.

In addition, we should avoid .load_super always return '0'
when level is LEVEL_MULTIPATH, which is not expected.

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1487373 ("Memory - illegal accesses")
Fixes: 6a5cb53aaa ("md: no longer compare spare disk superblock events in super_load")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:46:02 +01:00
Andrea Righi 47a417e7cf bcache: fix deadlock in bcache_allocator
[ Upstream commit 84c529aea1 ]

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 16:45:30 +01:00
Coly Li c17480cb33 bcache: fix static checker warning in bcache_device_free()
[ Upstream commit 2d8869518a ]

Commit cafe563591 ("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 16:45:26 +01:00
Guoqing Jiang 735f82e9f0 md/bitmap: avoid race window between md_bitmap_resize and bitmap_file_clear_bit
[ Upstream commit fadcbd2901 ]

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 16:44:20 +01:00
Yufen Yu 696b50bbf6 md: no longer compare spare disk superblock events in super_load
[ Upstream commit 6a5cb53aaa ]

We have a test case as follow:

  mdadm -CR /dev/md1 -l 1 -n 4 /dev/sd[a-d] \
	--assume-clean --bitmap=internal
  mdadm -S /dev/md1
  mdadm -A /dev/md1 /dev/sd[b-c] --run --force

  mdadm --zero /dev/sda
  mdadm /dev/md1 -a /dev/sda

  echo offline > /sys/block/sdc/device/state
  echo offline > /sys/block/sdb/device/state
  sleep 5
  mdadm -S /dev/md1

  echo running > /sys/block/sdb/device/state
  echo running > /sys/block/sdc/device/state
  mdadm -A /dev/md1 /dev/sd[a-c] --run --force

When we readd /dev/sda to the array, it started to do recovery.
After offline the other two disks in md1, the recovery have
been interrupted and superblock update info cannot be written
to the offline disks. While the spare disk (/dev/sda) can continue
to update superblock info.

After stopping the array and assemble it, we found the array
run fail, with the follow kernel message:

[  172.986064] md: kicking non-fresh sdb from array!
[  173.004210] md: kicking non-fresh sdc from array!
[  173.022383] md/raid1:md1: active with 0 out of 4 mirrors
[  173.022406] md1: failed to create bitmap (-5)
[  173.023466] md: md1 stopped.

Since both sdb and sdc have the value of 'sb->events' smaller than
that in sda, they have been kicked from the array. However, the only
remained disk sda is in 'spare' state before stop and it cannot be
added to conf->mirrors[] array. In the end, raid array assemble
and run fail.

In fact, we can use the older disk sdb or sdc to assemble the array.
That means we should not choose the 'spare' disk as the fresh disk in
analyze_sbs().

To fix the problem, we do not compare superblock events when it is
a spare disk, as same as validate_super.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:44:19 +01:00
Nikos Tsironis e3e1ba0bef dm thin: Flush data device before committing metadata
commit 694cfe7f31 upstream.

The thin provisioning target maintains per thin device mappings that map
virtual blocks to data blocks in the data device.

When we write to a shared block, in case of internal snapshots, or
provision a new block, in case of external snapshots, we copy the shared
block to a new data block (COW), update the mapping for the relevant
virtual block and then issue the write to the new data block.

Suppose the data device has a volatile write-back cache and the
following sequence of events occur:

1. We write to a shared block
2. A new data block is allocated
3. We copy the shared block to the new data block using kcopyd (COW)
4. We insert the new mapping for the virtual block in the btree for that
   thin device.
5. The commit timeout expires and we commit the metadata, that now
   includes the new mapping from step (4).
6. The system crashes and the data device's cache has not been flushed,
   meaning that the COWed data are lost.

The next time we read that virtual block of the thin device we read it
from the data block allocated in step (2), since the metadata have been
successfully committed. The data are lost due to the crash, so we read
garbage instead of the old, shared data.

This has the following implications:

1. In case of writes to shared blocks, with size smaller than the pool's
   block size (which means we first copy the whole block and then issue
   the smaller write), we corrupt data that the user never touched.

2. In case of writes to shared blocks, with size equal to the device's
   logical block size, we fail to provide atomic sector writes. When the
   system recovers the user will read garbage from that sector instead
   of the old data or the new data.

3. Even for writes to shared blocks, with size equal to the pool's block
   size (overwrites), after the system recovers, the written sectors
   will contain garbage instead of a random mix of sectors containing
   either old data or new data, thus we fail again to provide atomic
   sectors writes.

4. Even when the user flushes the thin device, because we first commit
   the metadata and then pass down the flush, the same risk for
   corruption exists (if the system crashes after the metadata have been
   committed but before the flush is passed down to the data device.)

The only case which is unaffected is that of writes with size equal to
the pool's block size and with the FUA flag set. But, because FUA writes
trigger metadata commits, this case can trigger the corruption
indirectly.

Moreover, apart from internal and external snapshots, the same issue
exists for newly provisioned blocks, when block zeroing is enabled.
After the system recovers the provisioned blocks might contain garbage
instead of zeroes.

To solve this and avoid the potential data corruption we flush the
pool's data device **before** committing its metadata.

This ensures that the data blocks of any newly inserted mappings are
properly written to non-volatile storage and won't be lost in case of a
crash.

Cc: stable@vger.kernel.org
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.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 11:05:03 +01:00
Nikos Tsironis d2688d36ce dm thin metadata: Add support for a pre-commit callback
commit ecda7c0280 upstream.

Add support for one pre-commit callback which is run right before the
metadata are committed.

This allows the thin provisioning target to run a callback before the
metadata are committed and is required by the next commit.

Cc: stable@vger.kernel.org
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.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 11:05:01 +01:00
Nikos Tsironis a802c5c9f4 dm clone: Flush destination device before committing metadata
commit 8b3fd1f53a upstream.

dm-clone maintains an on-disk bitmap which records which regions are
valid in the destination device, i.e., which regions have already been
hydrated, or have been written to directly, via user I/O.

Setting a bit in the on-disk bitmap meas the corresponding region is
valid in the destination device and we redirect all I/O regarding it to
the destination device.

Suppose the destination device has a volatile write-back cache and the
following sequence of events occur:

1. A region gets hydrated, either through the background hydration or
   because it was written to directly, via user I/O.

2. The commit timeout expires and we commit the metadata, marking that
   region as valid in the destination device.

3. The system crashes and the destination device's cache has not been
   flushed, meaning the region's data are lost.

The next time we read that region we read it from the destination
device, since the metadata have been successfully committed, but the
data are lost due to the crash, so we read garbage instead of the old
data.

This has several implications:

1. In case of background hydration or of writes with size smaller than
   the region size (which means we first copy the whole region and then
   issue the smaller write), we corrupt data that the user never
   touched.

2. In case of writes with size equal to the device's logical block size,
   we fail to provide atomic sector writes. When the system recovers the
   user will read garbage from the sector instead of the old data or the
   new data.

3. In case of writes without the FUA flag set, after the system
   recovers, the written sectors will contain garbage instead of a
   random mix of sectors containing either old data or new data, thus we
   fail again to provide atomic sector writes.

4. Even when the user flushes the dm-clone device, because we first
   commit the metadata and then pass down the flush, the same risk for
   corruption exists (if the system crashes after the metadata have been
   committed but before the flush is passed down).

The only case which is unaffected is that of writes with size equal to
the region size and with the FUA flag set. But, because FUA writes
trigger metadata commits, this case can trigger the corruption
indirectly.

To solve this and avoid the potential data corruption we flush the
destination device **before** committing the metadata.

This ensures that any freshly hydrated regions, for which we commit the
metadata, are properly written to non-volatile storage and won't be lost
in case of a crash.

Fixes: 7431b7835f ("dm: add clone target")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21 11:05:01 +01:00
Nikos Tsironis f03887fcb1 dm clone metadata: Use a two phase commit
commit 8fdbfe8d16 upstream.

Split the metadata commit in two parts:

1. dm_clone_metadata_pre_commit(): Prepare the current transaction for
   committing. After this is called, all subsequent metadata updates,
   done through either dm_clone_set_region_hydrated() or
   dm_clone_cond_set_range(), will be part of the next transaction.

2. dm_clone_metadata_commit(): Actually commit the current transaction
   to disk and start a new transaction.

This is required by the following commit. It allows dm-clone to flush
the destination device after step (1) to ensure that all freshly
hydrated regions, for which we are updating the metadata, are properly
written to non-volatile storage and won't be lost in case of a crash.

Fixes: 7431b7835f ("dm: add clone target")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21 11:05:00 +01:00
Nikos Tsironis aeb8a795f6 dm clone metadata: Track exact changes per transaction
commit e6a505f3f9 upstream.

Extend struct dirty_map with a second bitmap which tracks the exact
regions that were hydrated during the current metadata transaction.

Moreover, fix __flush_dmap() to only commit the metadata of the regions
that were hydrated during the current transaction.

This is required by the following commits to fix a data corruption bug.

Fixes: 7431b7835f ("dm: add clone target")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21 11:04:59 +01:00
Hou Tao 3f07f8a999 dm btree: increase rebalance threshold in __rebalance2()
commit 474e559567 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 11:04:57 +01:00
Mike Snitzer 7e53ea4a16 dm mpath: remove harmful bio-based optimization
commit dbaf971c9c upstream.

Removes the branching for edge-case where no SCSI device handler
exists.  The __map_bio_fast() method was far too limited, by only
selecting a new pathgroup or path IFF there was a path failure, fix this
be eliminating it in favor of __map_bio().  __map_bio()'s extra SCSI
device handler specific MPATHF_PG_INIT_REQUIRED test is not in the fast
path anyway.

This change restores full path selector functionality for bio-based
configurations that don't haave a SCSI device handler.  But it should be
noted that the path selectors do have an impact on performance for
certain networks that are extremely fast (and don't require frequent
switching).

Fixes: 8d47e65948 ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks")
Cc: stable@vger.kernel.org
Reported-by: Drew Hastings <dhastings@crucialwebhost.com>
Suggested-by: Martin Wilck <mwilck@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21 11:04:56 +01:00
David Jeffery f020809b84 md: improve handling of bio with REQ_PREFLUSH in md_flush_request()
commit 775d78319f upstream.

If pers->make_request fails in md_flush_request(), the bio is lost. To
fix this, pass back a bool to indicate if the original make_request call
should continue to handle the I/O and instead of assuming the flush logic
will push it to completion.

Convert md_flush_request to return a bool and no longer calls the raid
driver's make_request function.  If the return is true, then the md flush
logic has or will complete the bio and the md make_request call is done.
If false, then the md make_request function needs to keep processing like
it is a normal bio. Let the original call to md_handle_request handle any
need to retry sending the bio to the raid driver's make_request function
should it be needed.

Also mark md_flush_request and the make_request function pointer as
__must_check to issue warnings should these critical return values be
ignored.

Fixes: 2bc13b83e6 ("md: batch flush requests.")
Cc: stable@vger.kernel.org # # v4.19+
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:56:14 +01:00
Dmitry Fomichev fca436251d dm zoned: reduce overhead of backing device checks
commit e7fad909b6 upstream.

Commit 75d66ffb48 added backing device health checks and as a part
of these checks, check_events() block ops template call is invoked in
dm-zoned mapping path as well as in reclaim and flush path. Calling
check_events() with ATA or SCSI backing devices introduces a blocking
scsi_test_unit_ready() call being made in sd_check_events(). Even though
the overhead of calling scsi_test_unit_ready() is small for ATA zoned
devices, it is much larger for SCSI and it affects performance in a very
negative way.

Fix this performance regression by executing check_events() only in case
of any I/O errors. The function dmz_bdev_is_dying() is modified to call
only blk_queue_dying(), while calls to check_events() are made in a new
helper function, dmz_check_bdev().

Reported-by: zhangxiaoxu <zhangxiaoxu5@huawei.com>
Fixes: 75d66ffb48 ("dm zoned: properly handle backing device failure")
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:56:12 +01:00
Maged Mokhtar 26fe630624 dm writecache: handle REQ_FUA
commit c1005322ff upstream.

Call writecache_flush() on REQ_FUA in writecache_map().

Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Maged Mokhtar <mmokhtar@petasan.org>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 19:56:11 +01:00
Dan Carpenter 526152a239 md/raid0: Fix an error message in raid0_make_request()
[ Upstream commit e3fc3f3d09 ]

The first argument to WARN() is supposed to be a condition.  The
original code will just print the mdname() instead of the full warning
message.

Fixes: c84a1372df ("md/raid0: avoid RAID0 data corruption due to layout confusion.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-13 08:43:29 +01:00
John Pittman 8ac794da75 md/raid10: prevent access of uninitialized resync_pages offset
commit 45422b704d upstream.

Due to unneeded multiplication in the out_free_pages portion of
r10buf_pool_alloc(), when using a 3-copy raid10 layout, it is
possible to access a resync_pages offset that has not been
initialized.  This access translates into a crash of the system
within resync_free_pages() while passing a bad pointer to
put_page().  Remove the multiplication, preventing access to the
uninitialized area.

Fixes: f025061836 ("md: raid10: don't use bio's vec table to manage resync pages")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: John Pittman <jpittman@redhat.com>
Suggested-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-29 10:09:45 +01:00
Mike Snitzer 191355a2cf Revert "dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues"
commit f612b2132d upstream.

This reverts commit a1b89132dc.

Revert required hand-patching due to subsequent changes that were
applied since commit a1b89132dc.

Requires: ed0302e830 ("dm crypt: make workqueue names device-specific")
Cc: stable@vger.kernel.org
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=199857
Reported-by: Vito Caputo <vcaputo@pengaru.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-29 10:09:44 +01:00
Linus Torvalds d418d07005 for-linus-2019-10-18
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Merge tag 'for-linus-2019-10-18' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Keith that address deadlocks, double resets,
   memory leaks, and other regression.

 - Fixup elv_support_iosched() for bio based devices (Damien)

 - Fixup for the ahci PCS quirk (Dan)

 - Socket O_NONBLOCK handling fix for io_uring (me)

 - Timeout sequence io_uring fixes (yangerkun)

 - MD warning fix for parameter default_layout (Song)

 - blkcg activation fixes (Tejun)

 - blk-rq-qos node deletion fix (Tejun)

* tag 'for-linus-2019-10-18' of git://git.kernel.dk/linux-block:
  nvme-pci: Set the prp2 correctly when using more than 4k page
  io_uring: fix logic error in io_timeout
  io_uring: fix up O_NONBLOCK handling for sockets
  md/raid0: fix warning message for parameter default_layout
  libata/ahci: Fix PCS quirk application
  blk-rq-qos: fix first node deletion of rq_qos_del()
  blkcg: Fix multiple bugs in blkcg_activate_policy()
  io_uring: consider the overflow of sequence for timeout req
  nvme-tcp: fix possible leakage during error flow
  nvmet-loop: fix possible leakage during error flow
  block: Fix elv_support_iosched()
  nvme-tcp: Initialize sk->sk_ll_usec only with NET_RX_BUSY_POLL
  nvme: Wait for reset state when required
  nvme: Prevent resets during paused controller state
  nvme: Restart request timers in resetting state
  nvme: Remove ADMIN_ONLY state
  nvme-pci: Free tagset if no IO queues
  nvme: retain split access workaround for capability reads
  nvme: fix possible deadlock when nvme_update_formats fails
2019-10-18 22:29:36 -04:00
Mikulas Patocka 13bd677a47 dm cache: fix bugs when a GFP_NOWAIT allocation fails
GFP_NOWAIT allocation can fail anytime - it doesn't wait for memory being
available and it fails if the mempool is exhausted and there is not enough
memory.

If we go down this path:
  map_bio -> mg_start -> alloc_migration -> mempool_alloc(GFP_NOWAIT)
we can see that map_bio() doesn't check the return value of mg_start(),
and the bio is leaked.

If we go down this path:
  map_bio -> mg_start -> mg_lock_writes -> alloc_prison_cell ->
  dm_bio_prison_alloc_cell_v2 -> mempool_alloc(GFP_NOWAIT) ->
  mg_lock_writes -> mg_complete
the bio is ended with an error - it is unacceptable because it could
cause filesystem corruption if the machine ran out of memory
temporarily.

Change GFP_NOWAIT to GFP_NOIO, so that the mempool code will properly
wait until memory becomes available. mempool_alloc with GFP_NOIO can't
fail, so remove the code paths that deal with allocation failure.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-17 11:13:50 -04:00
Song Liu 3874d73e06 md/raid0: fix warning message for parameter default_layout
The message should match the parameter, i.e. raid0.default_layout.

Fixes: c84a1372df ("md/raid0: avoid RAID0 data corruption due to layout confusion.")
Cc: NeilBrown <neilb@suse.de>
Reported-by: Ivan Topolsky <doktor.yak@gmail.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-10-16 09:43:02 -07:00
Mikulas Patocka b21555786f dm snapshot: rework COW throttling to fix deadlock
Commit 721b1d98fb ("dm snapshot: Fix excessive memory usage and
workqueue stalls") introduced a semaphore to limit the maximum number of
in-flight kcopyd (COW) jobs.

The implementation of this throttling mechanism is prone to a deadlock:

1. One or more threads write to the origin device causing COW, which is
   performed by kcopyd.

2. At some point some of these threads might reach the s->cow_count
   semaphore limit and block in down(&s->cow_count), holding a read lock
   on _origins_lock.

3. Someone tries to acquire a write lock on _origins_lock, e.g.,
   snapshot_ctr(), which blocks because the threads at step (2) already
   hold a read lock on it.

4. A COW operation completes and kcopyd runs dm-snapshot's completion
   callback, which ends up calling pending_complete().
   pending_complete() tries to resubmit any deferred origin bios. This
   requires acquiring a read lock on _origins_lock, which blocks.

   This happens because the read-write semaphore implementation gives
   priority to writers, meaning that as soon as a writer tries to enter
   the critical section, no readers will be allowed in, until all
   writers have completed their work.

   So, pending_complete() waits for the writer at step (3) to acquire
   and release the lock. This writer waits for the readers at step (2)
   to release the read lock and those readers wait for
   pending_complete() (the kcopyd thread) to signal the s->cow_count
   semaphore: DEADLOCK.

The above was thoroughly analyzed and documented by Nikos Tsironis as
part of his initial proposal for fixing this deadlock, see:
https://www.redhat.com/archives/dm-devel/2019-October/msg00001.html

Fix this deadlock by reworking COW throttling so that it waits without
holding any locks. Add a variable 'in_progress' that counts how many
kcopyd jobs are running. A function wait_for_in_progress() will sleep if
'in_progress' is over the limit. It drops _origins_lock in order to
avoid the deadlock.

Reported-by: Guruswamy Basavaiah <guru2018@gmail.com>
Reported-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Tested-by: Nikos Tsironis <ntsironis@arrikto.com>
Fixes: 721b1d98fb ("dm snapshot: Fix excessive memory usage and workqueue stalls")
Cc: stable@vger.kernel.org # v5.0+
Depends-on: 4a3f111a73a8c ("dm snapshot: introduce account_start_copy() and account_end_copy()")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-10 09:46:05 -04:00
Mikulas Patocka a2f83e8b0c dm snapshot: introduce account_start_copy() and account_end_copy()
This simple refactoring moves code for modifying the semaphore cow_count
into separate functions to prepare for changes that will extend these
methods to provide for a more sophisticated mechanism for COW
throttling.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-10 09:45:48 -04:00
YueHaibing 0a005856d3 dm clone: Make __hash_find static
drivers/md/dm-clone-target.c:594:34: warning:
 symbol '__hash_find' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-10-08 14:04:54 -04:00
Linus Torvalds 2e959dd87a for-5.4/post-2019-09-24
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Merge tag 'for-5.4/post-2019-09-24' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "Some later additions that weren't quite done for the first pull
  request, and also a few fixes that have arrived since.

  This contains:

   - Kill silly pktcdvd warning on attempting to register a non-scsi
     passthrough device (me)

   - Use symbolic constants for the block t10 protection types, and
     switch to handling it in core rather than in the drivers (Max)

   - libahci platform missing node put fix (Nishka)

   - Small series of fixes for BFQ (Paolo)

   - Fix possible nbd crash (Xiubo)"

* tag 'for-5.4/post-2019-09-24' of git://git.kernel.dk/linux-block:
  block: drop device references in bsg_queue_rq()
  block: t10-pi: fix -Wswitch warning
  pktcdvd: remove warning on attempting to register non-passthrough dev
  ata: libahci_platform: Add of_node_put() before loop exit
  nbd: fix possible page fault for nbd disk
  nbd: rename the runtime flags as NBD_RT_ prefixed
  block, bfq: push up injection only after setting service time
  block, bfq: increase update frequency of inject limit
  block, bfq: reduce upper bound for inject limit to max_rq_in_driver+1
  block, bfq: update inject limit only after injection occurred
  block: centralize PI remapping logic to the block layer
  block: use symbolic constants for t10_pi type
2019-09-24 16:31:50 -07:00
Linus Torvalds 3e414b5bd2 - crypto and DM crypt advances that allow the crypto API to reclaim
implementation details that do not belong in DM crypt.  The wrapper
   template for ESSIV generation that was factored out will also be used
   by fscrypt in the future.
 
 - Add root hash pkcs#7 signature verification to the DM verity target.
 
 - Add a new "clone" DM target that allows for efficient remote
   replication of a device.
 
 - Enhance DM bufio's cache to be tailored to each client based on use.
   Clients that make heavy use of the cache get more of it, and those
   that use less have reduced cache usage.
 
 - Add a new DM_GET_TARGET_VERSION ioctl to allow userspace to query the
   version number of a DM target (even if the associated module isn't yet
   loaded).
 
 - Fix invalid memory access in DM zoned target.
 
 - Fix the max_discard_sectors limit advertised by the DM raid target; it
   was mistakenly storing the limit in bytes rather than sectors.
 
 - Small optimizations and cleanups in DM writecache target.
 
 - Various fixes and cleanups in DM core, DM raid1 and space map portion
   of DM persistent data library.
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Merge tag 'for-5.4/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - crypto and DM crypt advances that allow the crypto API to reclaim
   implementation details that do not belong in DM crypt. The wrapper
   template for ESSIV generation that was factored out will also be used
   by fscrypt in the future.

 - Add root hash pkcs#7 signature verification to the DM verity target.

 - Add a new "clone" DM target that allows for efficient remote
   replication of a device.

 - Enhance DM bufio's cache to be tailored to each client based on use.
   Clients that make heavy use of the cache get more of it, and those
   that use less have reduced cache usage.

 - Add a new DM_GET_TARGET_VERSION ioctl to allow userspace to query the
   version number of a DM target (even if the associated module isn't
   yet loaded).

 - Fix invalid memory access in DM zoned target.

 - Fix the max_discard_sectors limit advertised by the DM raid target;
   it was mistakenly storing the limit in bytes rather than sectors.

 - Small optimizations and cleanups in DM writecache target.

 - Various fixes and cleanups in DM core, DM raid1 and space map portion
   of DM persistent data library.

* tag 'for-5.4/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits)
  dm: introduce DM_GET_TARGET_VERSION
  dm bufio: introduce a global cache replacement
  dm bufio: remove old-style buffer cleanup
  dm bufio: introduce a global queue
  dm bufio: refactor adjust_total_allocated
  dm bufio: call adjust_total_allocated from __link_buffer and __unlink_buffer
  dm: add clone target
  dm raid: fix updating of max_discard_sectors limit
  dm writecache: skip writecache_wait for pmem mode
  dm stats: use struct_size() helper
  dm crypt: omit parsing of the encapsulated cipher
  dm crypt: switch to ESSIV crypto API template
  crypto: essiv - create wrapper template for ESSIV generation
  dm space map common: remove check for impossible sm_find_free() return value
  dm raid1: use struct_size() with kzalloc()
  dm writecache: optimize performance by sorting the blocks for writeback_all
  dm writecache: add unlikely for getting two block with same LBA
  dm writecache: remove unused member pointer in writeback_struct
  dm zoned: fix invalid memory access
  dm verity: add root hash pkcs#7 signature verification
  ...
2019-09-21 10:40:37 -07:00
Max Gurtovoy 54d4e6ab91 block: centralize PI remapping logic to the block layer
Currently t10_pi_prepare/t10_pi_complete functions are called during the
NVMe and SCSi layers command preparetion/completion, but their actual
place should be the block layer since T10-PI is a general data integrity
feature that is used by block storage protocols. Introduce .prepare_fn
and .complete_fn callbacks within the integrity profile that each type
can implement according to its needs.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>

Fixed to not call queue integrity functions if BLK_DEV_INTEGRITY
isn't defined in the config.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-17 20:03:49 -06:00
Linus Torvalds 7ad67ca553 for-5.4/block-2019-09-16
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Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Two NVMe pull requests:
     - ana log parse fix from Anton
     - nvme quirks support for Apple devices from Ben
     - fix missing bio completion tracing for multipath stack devices
       from Hannes and Mikhail
     - IP TOS settings for nvme rdma and tcp transports from Israel
     - rq_dma_dir cleanups from Israel
     - tracing for Get LBA Status command from Minwoo
     - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself
     - Some consolidation between the fabrics transports for handling
       the CAP register
     - reset race with ns scanning fix for fabrics (move fabrics
       commands to a dedicated request queue with a different lifetime
       from the admin request queue)."
     - controller reset and namespace scan races fixes
     - nvme discovery log change uevent support
     - naming improvements from Keith
     - multiple discovery controllers reject fix from James
     - some regular cleanups from various people

 - Series fixing (and re-fixing) null_blk debug printing and nr_devices
   checks (André)

 - A few pull requests from Song, with fixes from Andy, Guoqing,
   Guilherme, Neil, Nigel, and Yufen.

 - REQ_OP_ZONE_RESET_ALL support (Chaitanya)

 - Bio merge handling unification (Christoph)

 - Pick default elevator correctly for devices with special needs
   (Damien)

 - Block stats fixes (Hou)

 - Timeout and support devices nbd fixes (Mike)

 - Series fixing races around elevator switching and device add/remove
   (Ming)

 - sed-opal cleanups (Revanth)

 - Per device weight support for BFQ (Fam)

 - Support for blk-iocost, a new model that can properly account cost of
   IO workloads. (Tejun)

 - blk-cgroup writeback fixes (Tejun)

 - paride queue init fixes (zhengbin)

 - blk_set_runtime_active() cleanup (Stanley)

 - Block segment mapping optimizations (Bart)

 - lightnvm fixes (Hans/Minwoo/YueHaibing)

 - Various little fixes and cleanups

* tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits)
  null_blk: format pr_* logs with pr_fmt
  null_blk: match the type of parameter nr_devices
  null_blk: do not fail the module load with zero devices
  block: also check RQF_STATS in blk_mq_need_time_stamp()
  block: make rq sector size accessible for block stats
  bfq: Fix bfq linkage error
  raid5: use bio_end_sector in r5_next_bio
  raid5: remove STRIPE_OPS_REQ_PENDING
  md: add feature flag MD_FEATURE_RAID0_LAYOUT
  md/raid0: avoid RAID0 data corruption due to layout confusion.
  raid5: don't set STRIPE_HANDLE to stripe which is in batch list
  raid5: don't increment read_errors on EILSEQ return
  nvmet: fix a wrong error status returned in error log page
  nvme: send discovery log page change events to userspace
  nvme: add uevent variables for controller devices
  nvme: enable aen regardless of the presence of I/O queues
  nvme-fabrics: allow discovery subsystems accept a kato
  nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery()
  nvme: Remove redundant assignment of cq vector
  nvme: Assign subsys instance from first ctrl
  ...
2019-09-17 16:57:47 -07:00
Mikulas Patocka afa179eb60 dm: introduce DM_GET_TARGET_VERSION
This commit introduces a new ioctl DM_GET_TARGET_VERSION. It will load a
target that is specified in the "name" entry in the parameter structure
and return its version.

This functionality is intended to be used by cryptsetup, so that it can
query kernel capabilities before activating the device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-16 10:18:01 -04:00
Mikulas Patocka 6e913b28cd dm bufio: introduce a global cache replacement
This commit introduces a global cache replacement (instead of per-client
cleanup).

If one bufio client uses the cache heavily and another client is not using
it, we want to let the first client use most of the cache. The old
algorithm would partition the cache equally betwen the clients and that is
sub-optimal.

For cache replacement, we use the clock algorithm because it doesn't
require taking any lock when the buffer is accessed.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-13 17:00:21 -04:00
Guoqing Jiang 067df25c83 raid5: use bio_end_sector in r5_next_bio
Actually, we calculate bio's end sector here, so use the common
way for the purpose.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-13 13:14:43 -07:00
Guoqing Jiang feb9bf9849 raid5: remove STRIPE_OPS_REQ_PENDING
This stripe state is not used anymore after commit 51acbcec6c
("md: remove CONFIG_MULTICORE_RAID456"), so remove the obsoleted
state.

gjiang@nb01257:~/md$ grep STRIPE_OPS_REQ_PENDING drivers/md/ -r
drivers/md/raid5.c:					  (1 << STRIPE_OPS_REQ_PENDING) |
drivers/md/raid5.h:	STRIPE_OPS_REQ_PENDING,

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-13 13:14:39 -07:00
NeilBrown 33f2c35a54 md: add feature flag MD_FEATURE_RAID0_LAYOUT
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>
2019-09-13 13:10:06 -07:00
NeilBrown c84a1372df md/raid0: avoid RAID0 data corruption due to layout confusion.
If the drives in a RAID0 are not all the same size, the array is
divided into zones.
The first zone covers all drives, to the size of the smallest.
The second zone covers all drives larger than the smallest, up to
the size of the second smallest - etc.

A change in Linux 3.14 unintentionally changed the layout for the
second and subsequent zones.  All the correct data is still stored, but
each chunk may be assigned to a different device than in pre-3.14 kernels.
This can lead to data corruption.

It is not possible to determine what layout to use - it depends which
kernel the data was written by.
So we add a module parameter to allow the old (0) or new (1) layout to be
specified, and refused to assemble an affected array if that parameter is
not set.

Fixes: 20d0189b10 ("block: Introduce new bio_split()")
cc: stable@vger.kernel.org (3.14+)
Acked-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-13 13:10:05 -07:00
Guoqing Jiang 6ce220dd2f raid5: don't set STRIPE_HANDLE to stripe which is in batch list
If stripe in batch list is set with STRIPE_HANDLE flag, then the stripe
could be set with STRIPE_ACTIVE by the handle_stripe function. And if
error happens to the batch_head at the same time, break_stripe_batch_list
is called, then below warning could happen (the same report in [1]), it
means a member of batch list was set with STRIPE_ACTIVE.

[7028915.431770] stripe state: 2001
[7028915.431815] ------------[ cut here ]------------
[7028915.431828] WARNING: CPU: 18 PID: 29089 at drivers/md/raid5.c:4614 break_stripe_batch_list+0x203/0x240 [raid456]
[...]
[7028915.431879] CPU: 18 PID: 29089 Comm: kworker/u82:5 Tainted: G           O    4.14.86-1-storage #4.14.86-1.2~deb9
[7028915.431881] Hardware name: Supermicro SSG-2028R-ACR24L/X10DRH-iT, BIOS 3.1 06/18/2018
[7028915.431888] Workqueue: raid5wq raid5_do_work [raid456]
[7028915.431890] task: ffff9ab0ef36d7c0 task.stack: ffffb72926f84000
[7028915.431896] RIP: 0010:break_stripe_batch_list+0x203/0x240 [raid456]
[7028915.431898] RSP: 0018:ffffb72926f87ba8 EFLAGS: 00010286
[7028915.431900] RAX: 0000000000000012 RBX: ffff9aaa84a98000 RCX: 0000000000000000
[7028915.431901] RDX: 0000000000000000 RSI: ffff9ab2bfa15458 RDI: ffff9ab2bfa15458
[7028915.431902] RBP: ffff9aaa8fb4e900 R08: 0000000000000001 R09: 0000000000002eb4
[7028915.431903] R10: 00000000ffffffff R11: 0000000000000000 R12: ffff9ab1736f1b00
[7028915.431904] R13: 0000000000000000 R14: ffff9aaa8fb4e900 R15: 0000000000000001
[7028915.431906] FS:  0000000000000000(0000) GS:ffff9ab2bfa00000(0000) knlGS:0000000000000000
[7028915.431907] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[7028915.431908] CR2: 00007ff953b9f5d8 CR3: 0000000bf4009002 CR4: 00000000003606e0
[7028915.431909] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[7028915.431910] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[7028915.431910] Call Trace:
[7028915.431923]  handle_stripe+0x8e7/0x2020 [raid456]
[7028915.431930]  ? __wake_up_common_lock+0x89/0xc0
[7028915.431935]  handle_active_stripes.isra.58+0x35f/0x560 [raid456]
[7028915.431939]  raid5_do_work+0xc6/0x1f0 [raid456]

Also commit 59fc630b8b ("RAID5: batch adjacent full stripe write")
said "If a stripe is added to batch list, then only the first stripe
of the list should be put to handle_list and run handle_stripe."

So don't set STRIPE_HANDLE to stripe which is already in batch list,
otherwise the stripe could be put to handle_list and run handle_stripe,
then the above warning could be triggered.

[1]. https://www.spinics.net/lists/raid/msg62552.html

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-13 13:10:05 -07:00
Nigel Croxon b76b4715eb raid5: don't increment read_errors on EILSEQ return
While MD continues to count read errors returned by the lower layer.
If those errors are -EILSEQ, instead of -EIO, it should NOT increase
the read_errors count.

When RAID6 is set up on dm-integrity target that detects massive
corruption, the leg will be ejected from the array.  Even if the
issue is correctable with a sector re-write and the array has
necessary redundancy to correct it.

The leg is ejected because it runs up the rdev->read_errors beyond
conf->max_nr_stripes.  The return status in dm-drypt when there is
a data integrity error is -EILSEQ (BLK_STS_PROTECTION).

Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-13 13:10:05 -07:00
Mikulas Patocka b132ff3332 dm bufio: remove old-style buffer cleanup
Remove code that cleans up buffers if the cache size grows over the limit.

The next commit will introduce a new global cleanup.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-13 10:43:48 -04:00
Mikulas Patocka af53badc0c dm bufio: introduce a global queue
Rename param_spinlock to global_spinlock and introduce a global queue of
all used buffers.  The queue will be used in the following commits.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-13 10:43:27 -04:00
Mikulas Patocka d0a328a385 dm bufio: refactor adjust_total_allocated
Refactor adjust_total_allocated() so that it takes a bool argument
indicating if it should add or subtract the buffer size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-13 10:43:07 -04:00
Mikulas Patocka 26d2ef0cd0 dm bufio: call adjust_total_allocated from __link_buffer and __unlink_buffer
Move the call to adjust_total_allocated() to __link_buffer() and
__unlink_buffer() so that only used buffers are counted.  Reserved
buffers are not.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-13 10:42:27 -04:00
Nikos Tsironis 7431b7835f dm: add clone target
Add the dm-clone target, which allows cloning of arbitrary block
devices.

dm-clone produces a one-to-one copy of an existing, read-only source
device into a writable destination device: It presents a virtual block
device which makes all data appear immediately, and redirects reads and
writes accordingly.

The main use case of dm-clone is to clone a potentially remote,
high-latency, read-only, archival-type block device into a writable,
fast, primary-type device for fast, low-latency I/O. The cloned device
is visible/mountable immediately and the copy of the source device to
the destination device happens in the background, in parallel with user
I/O.

When the cloning completes, the dm-clone table can be removed altogether
and be replaced, e.g., by a linear table, mapping directly to the
destination device.

For further information and examples of how to use dm-clone, please read
Documentation/admin-guide/device-mapper/dm-clone.rst

Suggested-by: Vangelis Koukis <vkoukis@arrikto.com>
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-12 09:32:31 -04:00
Ming Lei c8156fc77d dm raid: fix updating of max_discard_sectors limit
Unit of 'chunk_size' is byte, instead of sector, so fix it by setting
the queue_limits' max_discard_sectors to rs->md.chunk_sectors.  Also,
rename chunk_size to chunk_size_bytes.

Without this fix, too big max_discard_sectors is applied on the request
queue of dm-raid, finally raid code has to split the bio again.

This re-split done by raid causes the following nested clone_endio:

1) one big bio 'A' is submitted to dm queue, and served as the original
bio

2) one new bio 'B' is cloned from the original bio 'A', and .map()
is run on this bio of 'B', and B's original bio points to 'A'

3) raid code sees that 'B' is too big, and split 'B' and re-submit
the remainded part of 'B' to dm-raid queue via generic_make_request().

4) now dm will handle 'B' as new original bio, then allocate a new
clone bio of 'C' and run .map() on 'C'. Meantime C's original bio
points to 'B'.

5) suppose now 'C' is completed by raid directly, then the following
clone_endio() is called recursively:

	clone_endio(C)
		->clone_endio(B)		#B is original bio of 'C'
			->bio_endio(A)

'A' can be big enough to make hundreds of nested clone_endio(), then
stack can be corrupted easily.

Fixes: 61697a6abd ("dm: eliminate 'split_discard_bios' flag from DM target interface")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-11 16:18:23 -04:00
Damien Le Moal 737eb78e82 block: Delay default elevator initialization
When elevator_init_mq() is called from blk_mq_init_allocated_queue(),
the only information known about the device is the number of hardware
queues as the block device scan by the device driver is not completed
yet for most drivers. The device type and elevator required features
are not set yet, preventing to correctly select the default elevator
most suitable for the device.

This currently affects all multi-queue zoned block devices which default
to the "none" elevator instead of the required "mq-deadline" elevator.
These drives currently include host-managed SMR disks connected to a
smartpqi HBA and null_blk block devices with zoned mode enabled.
Upcoming NVMe Zoned Namespace devices will also be affected.

Fix this by adding the boolean elevator_init argument to
blk_mq_init_allocated_queue() to control the execution of
elevator_init_mq(). Two cases exist:
1) elevator_init = false is used for calls to
   blk_mq_init_allocated_queue() within blk_mq_init_queue(). In this
   case, a call to elevator_init_mq() is added to __device_add_disk(),
   resulting in the delayed initialization of the queue elevator
   after the device driver finished probing the device information. This
   effectively allows elevator_init_mq() access to more information
   about the device.
2) elevator_init = true preserves the current behavior of initializing
   the elevator directly from blk_mq_init_allocated_queue(). This case
   is used for the special request based DM devices where the device
   gendisk is created before the queue initialization and device
   information (e.g. queue limits) is already known when the queue
   initialization is executed.

Additionally, to make sure that the elevator initialization is never
done while requests are in-flight (there should be none when the device
driver calls device_add_disk()), freeze and quiesce the device request
queue before calling blk_mq_init_sched() in elevator_init_mq().

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-05 19:52:34 -06:00
Huaisheng Ye 6d1959138c dm writecache: skip writecache_wait for pmem mode
The array bio_in_progress[2] only have chance to be increased and
decreased with ssd mode. For pmem mode, they are not involved at all.
So skip writecache_wait_for_ios in writecache_flush for pmem.

Suggested-by: Doris Yu <tyu1@lenovo.com>
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-05 13:22:05 -04:00
Gustavo A. R. Silva fb16c799b8 dm stats: use struct_size() helper
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct dm_stat {
	...
        struct dm_stat_shared stat_shared[0];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(struct dm_stat) + (size_t)n_entries * sizeof(struct dm_stat_shared)

with:

struct_size(s, stat_shared, n_entries)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-04 09:39:22 -04:00
Guoqing Jiang b0f01ecf29 md/raid5: use bio_end_sector to calculate last_sector
Use the common way to get last_sector.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-03 14:52:38 -07:00
Yufen Yu 07f1a6850c md/raid1: fail run raid1 array when active disk less than one
When run test case:
  mdadm -CR /dev/md1 -l 1 -n 4 /dev/sd[a-d] --assume-clean --bitmap=internal
  mdadm -S /dev/md1
  mdadm -A /dev/md1 /dev/sd[b-c] --run --force

  mdadm --zero /dev/sda
  mdadm /dev/md1 -a /dev/sda

  echo offline > /sys/block/sdc/device/state
  echo offline > /sys/block/sdb/device/state
  sleep 5
  mdadm -S /dev/md1

  echo running > /sys/block/sdb/device/state
  echo running > /sys/block/sdc/device/state
  mdadm -A /dev/md1 /dev/sd[a-c] --run --force

mdadm run fail with kernel message as follow:
[  172.986064] md: kicking non-fresh sdb from array!
[  173.004210] md: kicking non-fresh sdc from array!
[  173.022383] md/raid1:md1: active with 0 out of 4 mirrors
[  173.022406] md1: failed to create bitmap (-5)

In fact, when active disk in raid1 array less than one, we
need to return fail in raid1_run().

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-03 14:52:03 -07:00
Guilherme G. Piccoli 62f7b1989c md raid0/linear: Mark array as 'broken' and fail BIOs if a member is gone
Currently md raid0/linear are not provided with any mechanism to validate
if an array member got removed or failed. The driver keeps sending BIOs
regardless of the state of array members, and kernel shows state 'clean'
in the 'array_state' sysfs attribute. This leads to the following
situation: if a raid0/linear array member is removed and the array is
mounted, some user writing to this array won't realize that errors are
happening unless they check dmesg or perform one fsync per written file.
Despite udev signaling the member device is gone, 'mdadm' cannot issue the
STOP_ARRAY ioctl successfully, given the array is mounted.

In other words, no -EIO is returned and writes (except direct ones) appear
normal. Meaning the user might think the wrote data is correctly stored in
the array, but instead garbage was written given that raid0 does stripping
(and so, it requires all its members to be working in order to not corrupt
data). For md/linear, writes to the available members will work fine, but
if the writes go to the missing member(s), it'll cause a file corruption
situation, whereas the portion of the writes to the missing devices aren't
written effectively.

This patch changes this behavior: we check if the block device's gendisk
is UP when submitting the BIO to the array member, and if it isn't, we flag
the md device as MD_BROKEN and fail subsequent I/Os to that device; a read
request to the array requiring data from a valid member is still completed.
While flagging the device as MD_BROKEN, we also show a rate-limited warning
in the kernel log.

A new array state 'broken' was added too: it mimics the state 'clean' in
every aspect, being useful only to distinguish if the array has some member
missing. We rely on the MD_BROKEN flag to put the array in the 'broken'
state. This state cannot be written in 'array_state' as it just shows
one or more members of the array are missing but acts like 'clean', it
wouldn't make sense to write it.

With this patch, the filesystem reacts much faster to the event of missing
array member: after some I/O errors, ext4 for instance aborts the journal
and prevents corruption. Without this change, we're able to keep writing
in the disk and after a machine reboot, e2fsck shows some severe fs errors
that demand fixing. This patch was tested in ext4 and xfs filesystems, and
requires a 'mdadm' counterpart to handle the 'broken' state.

Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-09-03 14:49:28 -07:00
Ard Biesheuvel b1d1e29639 dm crypt: omit parsing of the encapsulated cipher
Only the ESSIV IV generation mode used to use cc->cipher so it could
instantiate the bare cipher used to encrypt the IV. However, this is
now taken care of by the ESSIV template, and so no users of cc->cipher
remain. So remove it altogether.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-03 16:46:16 -04:00
Ard Biesheuvel a1a262b66e dm crypt: switch to ESSIV crypto API template
Replace the explicit ESSIV handling in the dm-crypt driver with calls
into the crypto API, which now possesses the capability to perform
this processing within the crypto subsystem.

Note that we reorder the AEAD cipher_api string parsing with the TFM
instantiation: this is needed because cipher_api is mangled by the
ESSIV handling, and throws off the parsing of "authenc(" otherwise.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-03 16:45:54 -04:00
Kent Overstreet a22a9602b8 closures: fix a race on wakeup from closure_sync
The race was when a thread using closure_sync() notices cl->s->done == 1
before the thread calling closure_put() calls wake_up_process(). Then,
it's possible for that thread to return and exit just before
wake_up_process() is called - so we're trying to wake up a process that
no longer exists.

rcu_read_lock() is sufficient to protect against this, as there's an rcu
barrier somewhere in the process teardown path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-03 08:08:31 -06:00
Dan Carpenter d66c9920c0 bcache: Fix an error code in bch_dump_read()
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: cafe563591 ("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>
2019-09-03 08:08:29 -06:00
Shile Zhang d55a4ae9e1 bcache: add cond_resched() in __bch_cache_cmp()
Read /sys/fs/bcache/<uuid>/cacheN/priority_stats can take very long
time with huge cache after long run.

Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Tested-by: Heitor Alves de Siqueira <halves@canonical.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-03 08:08:28 -06:00
Nigel Croxon 0009fad033 raid5 improve too many read errors msg by adding limits
Often limits can be changed by admin. When discussing such things
it helps if you can provide "self-sustained" facts. Also
sometimes the admin thinks he changed a limit, but it did not
take effect for some reason or he changed the wrong thing.

V3: Only pr_warn when Faulty is 0.
V2: Add read_errors value to pr_warn.

Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-27 12:36:37 -07:00
NeilBrown 9d4b45d6af md: don't report active array_state until after revalidate_disk() completes.
Until revalidate_disk() has completed, the size of a new md array will
appear to be zero.
So we shouldn't report, through array_state, that the array is active
until that time.
udev rules check array_state to see if the array is ready.  As soon as
it appear to be zero, fsck can be run.  If it find the size to be
zero, it will fail.

So add a new flag to provide an interlock between do_md_run() and
array_state_show().  This flag is set while do_md_run() is active and
it prevents array_state_show() from reporting that the array is
active.

Before do_md_run() is called, ->pers will be NULL so array is
definitely not active.
After do_md_run() is called, revalidate_disk() will have run and the
array will be completely ready.

We also move various sysfs_notify*() calls out of md_run() into
do_md_run() after MD_NOT_READY is cleared.  This ensure the
information is ready before the notification is sent.

Prior to v4.12, array_state_show() was called with the
mddev->reconfig_mutex held, which provided exclusion with do_md_run().

Note that MD_NOT_READY cleared twice.  This is deliberate to cover
both success and error paths with minimal noise.

Fixes: b7b17c9b67 ("md: remove mddev_lock() from md_attr_show()")
Cc: stable@vger.kernel.org (v4.12++)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-27 12:36:37 -07:00
NeilBrown 480523feae md: only call set_in_sync() when it is expected to succeed.
Since commit 4ad23a9764 ("MD: use per-cpu counter for
writes_pending"), set_in_sync() is substantially more expensive: it
can wait for a full RCU grace period which can be 10s of milliseconds.

So we should only call it when the cost is justified.

md_check_recovery() currently calls set_in_sync() every time it finds
anything to do (on non-external active arrays).  For an array
performing resync or recovery, this will be quite often.
Each call will introduce a delay to the md thread, which can noticeable
affect IO submission latency.

In md_check_recovery() we only need to call set_in_sync() if
'safemode' was non-zero at entry, meaning that there has been not
recent IO.  So we save this "safemode was nonzero" state, and only
call set_in_sync() if it was non-zero.

This measurably reduces mean and maximum IO submission latency during
resync/recovery.

Reported-and-tested-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Fixes: 4ad23a9764 ("MD: use per-cpu counter for writes_pending")
Cc: stable@vger.kernel.org (v4.12+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-27 12:36:36 -07:00
ZhangXiaoxu c1499a044d dm space map common: remove check for impossible sm_find_free() return value
The function sm_find_free() just returns -ENOSPC and 0.
So remove lone caller's check for some other error.

Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 15:39:53 -04:00
Gustavo A. R. Silva bcd676542c dm raid1: use struct_size() with kzalloc()
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct mirror_set {
	...
        struct mirror mirror[0];
};

size = sizeof(struct mirror_set) + count * sizeof(struct mirror);
instance = kzalloc(size, GFP_KERNEL)

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, mirror, count), GFP_KERNEL)

Notice that, in this case, variable len is not necessary, hence it
is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 11:05:32 -04:00
Huaisheng Ye 5229b4896e dm writecache: optimize performance by sorting the blocks for writeback_all
During the process of writeback, the blocks, which have been placed in wbl.list
for writeback soon, are partially ordered for the contiguous ones.

When writeback_all has been set, for most cases, also by default, there will be
a lot of blocks in pmem need to writeback at the same time.
For this case, we could optimize the performance by sorting all blocks in
wbl.list. writecache_writeback doesn't need to get blocks from the tail of
wc->lru, whereas from the first rb_node from the rb_tree.

The benefit is that, writecache_writeback doesn't need to have any cost to sort
the blocks, because of all blocks are incremental originally in rb_tree.
There will be a writecache_flush when writeback_all begins to work, that will
eliminate duplicate blocks in cache by committed/uncommitted.

Testing platform: Thinksystem SR630 with persistent memory.
The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB
of which for using.

Testing steps:
 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4  4096 0'
 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite
 -ioengine=libaio -bs=4k -loops=1  -size=2g -group_reporting -name=mytest1
 3) time dmsetup message /dev/mapper/mycache 0 flush

Here is the results below,
With the patch:
 # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite
 -ioengine=libaio -bs=4k -loops=1  -size=2g -group_reporting -name=mytest1
   iops        : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197
 # time dmsetup message /dev/mapper/mycache 0 flush
real	0m44.020s
user	0m0.002s
sys	0m0.003s

Without the patch:
 # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite
 -ioengine=libaio -bs=4k -loops=1  -size=2g -group_reporting -name=mytest1
   iops        : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211
 # time dmsetup message /dev/mapper/mycache 0 flush
real	1m39.221s
user	0m0.001s
sys	0m0.003s

I also have checked the data accuracy with this patch by making EXT4 filesystem
on mycache, then mount it for checking md5 of files on that.
The test result is positive, with this patch it could save more than half of time
when writeback_all.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 10:59:00 -04:00
Huaisheng Ye 62421b3880 dm writecache: add unlikely for getting two block with same LBA
In function writecache_writeback, entries g and f has same original
sector only happens at entry f has been committed, but entry g has
NOT yet.

The probability of this happening is very low in the following
256 blocks at most of entry e.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 10:54:41 -04:00
Huaisheng Ye 58912dbce6 dm writecache: remove unused member pointer in writeback_struct
The stucture member pointer page in writeback_struct never has been
used actually. Remove it.

Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 10:54:15 -04:00
Mikulas Patocka 0c8e9c2d66 dm zoned: fix invalid memory access
Commit 75d66ffb48 ("dm zoned: properly
handle backing device failure") triggers a coverity warning:

*** CID 1452808:  Memory - illegal accesses  (USE_AFTER_FREE)
/drivers/md/dm-zoned-target.c: 137 in dmz_submit_bio()
131             clone->bi_private = bioctx;
132
133             bio_advance(bio, clone->bi_iter.bi_size);
134
135             refcount_inc(&bioctx->ref);
136             generic_make_request(clone);
>>>     CID 1452808:  Memory - illegal accesses  (USE_AFTER_FREE)
>>>     Dereferencing freed pointer "clone".
137             if (clone->bi_status == BLK_STS_IOERR)
138                     return -EIO;
139
140             if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone))
141                     zone->wp_block += nr_blocks;
142

The "clone" bio may be processed and freed before the check
"clone->bi_status == BLK_STS_IOERR" - so this check can access invalid
memory.

Fixes: 75d66ffb48 ("dm zoned: properly handle backing device failure")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26 10:33:58 -04:00
Jaskaran Khurana 88cd3e6cfa dm verity: add root hash pkcs#7 signature verification
The verification is to support cases where the root hash is not secured
by Trusted Boot, UEFI Secureboot or similar technologies.

One of the use cases for this is for dm-verity volumes mounted after
boot, the root hash provided during the creation of the dm-verity volume
has to be secure and thus in-kernel validation implemented here will be
used before we trust the root hash and allow the block device to be
created.

The signature being provided for verification must verify the root hash
and must be trusted by the builtin keyring for verification to succeed.

The hash is added as a key of type "user" and the description is passed
to the kernel so it can look it up and use it for verification.

Adds CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG which can be turned on if root
hash verification is needed.

Kernel commandline dm_verity module parameter 'require_signatures' will
indicate whether to force root hash signature verification (for all dm
verity volumes).

Signed-off-by: Jaskaran Khurana <jaskarankhurana@linux.microsoft.com>
Tested-and-Reviewed-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:13:14 -04:00
Ard Biesheuvel 39d13a1ac4 dm crypt: reuse eboiv skcipher for IV generation
Instead of instantiating a separate cipher to perform the encryption
needed to produce the IV, reuse the skcipher used for the block data
and invoke it one additional time for each block to encrypt a zero
vector and use the output as the IV.

For CBC mode, this is equivalent to using the bare block cipher, but
without the risk of ending up with a non-time invariant implementation
of AES when the skcipher itself is time variant (e.g., arm64 without
Crypto Extensions has a NEON based time invariant implementation of
cbc(aes) but no time invariant implementation of the core cipher other
than aes-ti, which is not enabled by default).

This approach is a compromise between dm-crypt API flexibility and
reducing dependence on parts of the crypto API that should not usually
be exposed to other subsystems, such as the bare cipher API.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:13:13 -04:00
Mikulas Patocka 123d87d553 dm: make dm_table_find_target return NULL
Currently, if we pass too high sector number to dm_table_find_target, it
returns zeroed dm_target structure and callers test if the structure is
zeroed with the macro dm_target_is_valid.

However, returning NULL is common practice to indicate errors.

This patch refactors the dm code, so that dm_table_find_target returns
NULL and its callers test the returned value for NULL. The macro
dm_target_is_valid is deleted. In alloc_targets, we no longer allocate an
extra zeroed target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:13:12 -04:00
Mikulas Patocka 1cfd5d3399 dm table: fix invalid memory accesses with too high sector number
If the sector number is too high, dm_table_find_target() should return a
pointer to a zeroed dm_target structure (the caller should test it with
dm_target_is_valid).

However, for some table sizes, the code in dm_table_find_target() that
performs btree lookup will access out of bound memory structures.

Fix this bug by testing the sector number at the beginning of
dm_table_find_target(). Also, add an "inline" keyword to the function
dm_table_get_size() because this is a hot path.

Fixes: 512875bd96 ("dm: table detect io beyond device")
Cc: stable@vger.kernel.org
Reported-by: Zhang Tao <kontais@zoho.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:11:42 -04:00
ZhangXiaoxu ae148243d3 dm space map metadata: fix missing store of apply_bops() return value
In commit 6096d91af0 ("dm space map metadata: fix occasional leak
of a metadata block on resize"), we refactor the commit logic to a new
function 'apply_bops'.  But when that logic was replaced in out() the
return value was not stored.  This may lead out() returning a wrong
value to the caller.

Fixes: 6096d91af0 ("dm space map metadata: fix occasional leak of a metadata block on resize")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-22 16:11:24 -04:00
ZhangXiaoxu e4f9d60138 dm btree: fix order of block initialization in btree_split_beneath
When btree_split_beneath() splits a node to two new children, it will
allocate two blocks: left and right.  If right block's allocation
failed, the left block will be unlocked and marked dirty.  If this
happened, the left block'ss content is zero, because it wasn't
initialized with the btree struct before the attempot to allocate the
right block.  Upon return, when flushing the left block to disk, the
validator will fail when check this block.  Then a BUG_ON is raised.

Fix this by completely initializing the left block before allocating and
initializing the right block.

Fixes: 4dcb8b57df ("dm btree: fix leak of bufio-backed block in btree_split_beneath error path")
Cc: stable@vger.kernel.org
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-22 16:11:23 -04:00
Wenwen Wang dc1a3e8e0c dm raid: add missing cleanup in raid_ctr()
If rs_prepare_reshape() fails, no cleanup is executed, leading to
leak of the raid_set structure allocated at the beginning of
raid_ctr(). To fix this issue, go to the label 'bad' if the error
occurs.

Fixes: 11e4723206 ("dm raid: stop keeping raid set frozen altogether")
Cc: stable@vger.kernel.org
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-21 11:47:05 -04:00
Dan Carpenter e0702d90b7 dm zoned: fix potential NULL dereference in dmz_do_reclaim()
This function is supposed to return error pointers so it matches the
dmz_get_rnd_zone_for_reclaim() function.  The current code could lead to
a NULL dereference in dmz_do_reclaim()

Fixes: b234c6d7a7 ("dm zoned: improve error handling in reclaim")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-21 11:29:30 -04:00
Bryan Gurney 08c04c84a5 dm dust: use dust block size for badblocklist index
Change the "frontend" dust_remove_block, dust_add_block, and
dust_query_block functions to store the "dust block number", instead
of the sector number corresponding to the "dust block number".

For the "backend" functions dust_map_read and dust_map_write,
right-shift by sect_per_block_shift.  This fixes the inability to
emulate failure beyond the first sector of each "dust block" (for
devices with a "dust block size" larger than 512 bytes).

Fixes: e4f3fabd67 ("dm: add dust target")
Cc: stable@vger.kernel.org
Signed-off-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-21 11:27:17 -04:00
Mikulas Patocka 5729b6e5a1 dm integrity: fix a crash due to BUG_ON in __journal_read_write()
Fix a crash that was introduced by the commit 724376a04d. The crash is
reported here: https://gitlab.com/cryptsetup/cryptsetup/issues/468

When reading from the integrity device, the function
dm_integrity_map_continue calls find_journal_node to find out if the
location to read is present in the journal. Then, it calculates how many
sectors are consecutively stored in the journal. Then, it locks the range
with add_new_range and wait_and_add_new_range.

The problem is that during wait_and_add_new_range, we hold no locks (we
don't hold ic->endio_wait.lock and we don't hold a range lock), so the
journal may change arbitrarily while wait_and_add_new_range sleeps.

The code then goes to __journal_read_write and hits
BUG_ON(journal_entry_get_sector(je) != logical_sector); because the
journal has changed.

In order to fix this bug, we need to re-check the journal location after
wait_and_add_new_range. We restrict the length to one block in order to
not complicate the code too much.

Fixes: 724376a04d ("dm integrity: implement fair range locks")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-15 16:01:57 -04:00
Dmitry Fomichev ad1bd578bd dm zoned: fix a few typos
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>
2019-08-15 15:57:43 -04:00
Dmitry Fomichev bae9a0aa33 dm zoned: add SPDX license identifiers
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>
2019-08-15 15:57:42 -04:00
Dmitry Fomichev 75d66ffb48 dm zoned: properly handle backing device failure
dm-zoned is observed to lock up or livelock in case of hardware
failure or some misconfiguration of the backing zoned device.

This patch adds a new dm-zoned target function that checks the status of
the backing device. If the request queue of the backing device is found
to be in dying state or the SCSI backing device enters offline state,
the health check code sets a dm-zoned target flag prompting all further
incoming I/O to be rejected. In order to detect backing device failures
timely, this new function is called in the request mapping path, at the
beginning of every reclaim run and before performing any metadata I/O.

The proper way out of this situation is to do

dmsetup remove <dm-zoned target>

and recreate the target when the problem with the backing device
is resolved.

Fixes: 3b1a94c88b ("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>
2019-08-15 15:57:42 -04:00
Dmitry Fomichev d7428c5011 dm zoned: improve error handling in i/o map code
Some errors are ignored in the I/O path during queueing chunks
for processing by chunk works. Since at least these errors are
transient in nature, it should be possible to retry the failed
incoming commands.

The fix -

Errors that can happen while queueing chunks are carried upwards
to the main mapping function and it now returns DM_MAPIO_REQUEUE
for any incoming requests that can not be properly queued.

Error logging/debug messages are added where needed.

Fixes: 3b1a94c88b ("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>
2019-08-15 15:57:41 -04:00
Dmitry Fomichev b234c6d7a7 dm zoned: improve error handling in reclaim
There are several places in reclaim code where errors are not
propagated to the main function, dmz_reclaim(). This function
is responsible for unlocking zones that might be still locked
at the end of any failed reclaim iterations. As the result,
some device zones may be left permanently locked for reclaim,
degrading target's capability to reclaim zones.

This patch fixes these issues as follows -

Make sure that dmz_reclaim_buf(), dmz_reclaim_seq_data() and
dmz_reclaim_rnd_data() return error codes to the caller.

dmz_reclaim() function is renamed to dmz_do_reclaim() to avoid
clashing with "struct dmz_reclaim" and is modified to return the
error to the caller.

dmz_get_zone_for_reclaim() now returns an error instead of NULL
pointer and reclaim code checks for that error.

Error logging/debug messages are added where necessary.

Fixes: 3b1a94c88b ("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>
2019-08-15 15:57:40 -04:00
Dmitry Fomichev d1fef41465 dm kcopyd: always complete failed jobs
This patch fixes a problem in dm-kcopyd that may leave jobs in
complete queue indefinitely in the event of backing storage failure.

This behavior has been observed while running 100% write file fio
workload against an XFS volume created on top of a dm-zoned target
device. If the underlying storage of dm-zoned goes to offline state
under I/O, kcopyd sometimes never issues the end copy callback and
dm-zoned reclaim work hangs indefinitely waiting for that completion.

This behavior was traced down to the error handling code in
process_jobs() function that places the failed job to complete_jobs
queue, but doesn't wake up the job handler. In case of backing device
failure, all outstanding jobs may end up going to complete_jobs queue
via this code path and then stay there forever because there are no
more successful I/O jobs to wake up the job handler.

This patch adds a wake() call to always wake up kcopyd job wait queue
for all I/O jobs that fail before dm_io() gets called for that job.

The patch also sets the write error status in all sub jobs that are
failed because their master job has failed.

Fixes: b73c67c2cb ("dm kcopyd: add sequential write feature")
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>
2019-08-15 15:57:39 -04:00
Mikulas Patocka cf3591ef83 Revert "dm bufio: fix deadlock with loop device"
Revert the commit bd293d071f. The proper
fix has been made available with commit d0a255e795 ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d071f doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d071f ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e795 ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-15 15:57:39 -04:00
Linus Torvalds 50e73a4a41 for-linus-20190809
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Merge tag 'for-linus-20190809' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Revert of a bcache patch that caused an oops for some (Coly)

 - ata rb532 unused warning fix (Gustavo)

 - AoE kernel crash fix (He)

 - Error handling fixup for blkdev_get() (Jan)

 - libata read/write translation and SFF PIO fix (me)

 - Use after free and error handling fix for O_DIRECT fragments. There's
   still a nowait + sync oddity in there, we'll nail that start next
   week. If all else fails, I'll queue a revert of the NOWAIT change.
   (me)

 - Loop GFP_KERNEL -> GFP_NOIO deadlock fix (Mikulas)

 - Two BFQ regression fixes that caused crashes (Paolo)

* tag 'for-linus-20190809' of git://git.kernel.dk/linux-block:
  bcache: Revert "bcache: use sysfs_match_string() instead of __sysfs_match_string()"
  loop: set PF_MEMALLOC_NOIO for the worker thread
  bdev: Fixup error handling in blkdev_get()
  block, bfq: handle NULL return value by bfq_init_rq()
  block, bfq: move update of waker and woken list to queue freeing
  block, bfq: reset last_completed_rq_bfqq if the pointed queue is freed
  block: aoe: Fix kernel crash due to atomic sleep when exiting
  libata: add SG safety checks in SFF pio transfers
  libata: have ata_scsi_rw_xlat() fail invalid passthrough requests
  block: fix O_DIRECT error handling for bio fragments
  ata: rb532_cf: Fix unused variable warning in rb532_pata_driver_probe
2019-08-09 09:28:18 -07:00
Coly Li 20621fedb2 bcache: Revert "bcache: use sysfs_match_string() instead of __sysfs_match_string()"
This reverts commit 89e0341af0.

In drivers/md/bcache/sysfs.c:bch_snprint_string_list(), NULL pointer at
the end of list is necessary. Remove the NULL from last element of each
lists will cause the following panic,

[ 4340.455652] bcache: register_cache() registered cache device nvme0n1
[ 4340.464603] bcache: register_bdev() registered backing device sdk
[ 4421.587335] bcache: bch_cached_dev_run() cached dev sdk is running already
[ 4421.587348] bcache: bch_cached_dev_attach() Caching sdk as bcache0 on set 354e1d46-d99f-4d8b-870b-078b80dc88a6
[ 5139.247950] general protection fault: 0000 [#1] SMP NOPTI
[ 5139.247970] CPU: 9 PID: 5896 Comm: cat Not tainted 4.12.14-95.29-default #1 SLE12-SP4
[ 5139.247988] Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 04/18/2019
[ 5139.248006] task: ffff888fb25c0b00 task.stack: ffff9bbacc704000
[ 5139.248021] RIP: 0010:string+0x21/0x70
[ 5139.248030] RSP: 0018:ffff9bbacc707bf0 EFLAGS: 00010286
[ 5139.248043] RAX: ffffffffa7e432e3 RBX: ffff8881c20da02a RCX: ffff0a00ffffff04
[ 5139.248058] RDX: 3f00656863616362 RSI: ffff8881c20db000 RDI: ffffffffffffffff
[ 5139.248075] RBP: ffff8881c20db000 R08: 0000000000000000 R09: ffff8881c20da02a
[ 5139.248090] R10: 0000000000000004 R11: 0000000000000000 R12: ffff9bbacc707c48
[ 5139.248104] R13: 0000000000000fd6 R14: ffffffffc0665855 R15: ffffffffc0665855
[ 5139.248119] FS:  00007faf253b8700(0000) GS:ffff88903f840000(0000) knlGS:0000000000000000
[ 5139.248137] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5139.248149] CR2: 00007faf25395008 CR3: 0000000f72150006 CR4: 00000000007606e0
[ 5139.248164] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5139.248179] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5139.248193] PKRU: 55555554
[ 5139.248200] Call Trace:
[ 5139.248210]  vsnprintf+0x1fb/0x510
[ 5139.248221]  snprintf+0x39/0x40
[ 5139.248238]  bch_snprint_string_list.constprop.15+0x5b/0x90 [bcache]
[ 5139.248256]  __bch_cached_dev_show+0x44d/0x5f0 [bcache]
[ 5139.248270]  ? __alloc_pages_nodemask+0xb2/0x210
[ 5139.248284]  bch_cached_dev_show+0x2c/0x50 [bcache]
[ 5139.248297]  sysfs_kf_seq_show+0xbb/0x190
[ 5139.248308]  seq_read+0xfc/0x3c0
[ 5139.248317]  __vfs_read+0x26/0x140
[ 5139.248327]  vfs_read+0x87/0x130
[ 5139.248336]  SyS_read+0x42/0x90
[ 5139.248346]  do_syscall_64+0x74/0x160
[ 5139.248358]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 5139.248370] RIP: 0033:0x7faf24eea370
[ 5139.248379] RSP: 002b:00007fff82d03f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 5139.248395] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007faf24eea370
[ 5139.248411] RDX: 0000000000020000 RSI: 00007faf25396000 RDI: 0000000000000003
[ 5139.248426] RBP: 00007faf25396000 R08: 00000000ffffffff R09: 0000000000000000
[ 5139.248441] R10: 000000007c9d4d41 R11: 0000000000000246 R12: 00007faf25396000
[ 5139.248456] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000fff
[ 5139.248892] Code: ff ff ff 0f 1f 80 00 00 00 00 49 89 f9 48 89 cf 48 c7 c0 e3 32 e4 a7 48 c1 ff 30 48 81 fa ff 0f 00 00 48 0f 46 d0 48 85 ff 74 45 <44> 0f b6 02 48 8d 42 01 45 84 c0 74 38 48 01 fa 4c 89 cf eb 0e

The simplest way to fix is to revert commit 89e0341af0 ("bcache: use
sysfs_match_string() instead of __sysfs_match_string()").

This bug was introduced in Linux v5.2, so this fix only applies to
Linux v5.2 is enough for stable tree maintainer.

Fixes: 89e0341af0 ("bcache: use sysfs_match_string() instead of __sysfs_match_string()")
Cc: stable@vger.kernel.org
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reported-by: Peifeng Lin <pflin@suse.com>
Acked-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-09 07:37:33 -06:00
Hou Tao 449808a254 raid1: factor out a common routine to handle the completion of sync write
It's just code clean-up.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Guoqing Jiang 0d8ed0e9bf md: don't call spare_active in md_reap_sync_thread if all member devices can't work
When add one disk to array, the md_reap_sync_thread is responsible
to activate the spare and set In_sync flag for the new member in
spare_active().

But if raid1 has one member disk A, and disk B is added to the array.
Then we offline A before all the datas are synchronized from A to B,
obviously B doesn't have the latest data as A, but B is still marked
with In_sync flag.

So let's not call spare_active under the condition, otherwise B is
still showed with 'U' state which is not correct.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Guoqing Jiang 062f5b2ae1 md: don't set In_sync if array is frozen
When a disk is added to array, the following path is called in mdadm.

Manage_subdevs -> sysfs_freeze_array
               -> Manage_add
               -> sysfs_set_str(&info, NULL, "sync_action","idle")

Then from kernel side, Manage_add invokes the path (add_new_disk ->
validate_super = super_1_validate) to set In_sync flag.

Since In_sync means "device is in_sync with rest of array", and the new
added disk need to resync thread to help the synchronization of data.
And md_reap_sync_thread would call spare_active to set In_sync for the
new added disk finally. So don't set In_sync if array is in frozen.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Guoqing Jiang 9a567843f7 md: allow last device to be forcibly removed from RAID1/RAID10.
When the 'last' device in a RAID1 or RAID10 reports an error,
we do not mark it as failed.  This would serve little purpose
as there is no risk of losing data beyond that which is obviously
lost (as there is with RAID5), and there could be other sectors
on the device which are readable, and only readable from this device.
This in general this maximises access to data.

However the current implementation also stops an admin from removing
the last device by direct action.  This is rarely useful, but in many
case is not harmful and can make automation easier by removing special
cases.

Also, if an attempt to write metadata fails the device must be marked
as faulty, else an infinite loop will result, attempting to update
the metadata on all non-faulty devices.

So add 'fail_last_dev' member to 'struct mddev', then we can bypasses
the 'last disk' checks for RAID1 and RAID10, and control the behavior
per array by change sysfs node.

Signed-off-by: NeilBrown <neilb@suse.de>
[add sysfs node for fail_last_dev by Guoqing]
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Andy Shevchenko cf89160793 md: Convert to use int_pow()
Instead of linear approach to calculate power of 10, use generic int_pow()
which does it better.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Yufen Yu 7cee6d4e60 md/raid10: end bio when the device faulty
Just like raid1, we do not queue write error bio to retry write
and acknowlege badblocks, when the device is faulty.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Yufen Yu eeba6809d8 md/raid1: end bio when the device faulty
When write bio return error, it would be added to conf->retry_list
and wait for raid1d thread to retry write and acknowledge badblocks.

In narrow_write_error(), the error bio will be split in the unit of
badblock shift (such as one sector) and raid1d thread issues them
one by one. Until all of the splited bio has finished, raid1d thread
can go on processing other things, which is time consuming.

But, there is a scene for error handling that is not necessary.
When the device has been set faulty, flush_bio_list() may end
bios in pending_bio_list with error status. Since these bios
has not been issued to the device actually, error handlding to
retry write and acknowledge badblocks make no sense.

Even without that scene, when the device is faulty, badblocks info
can not be written out to the device. Thus, we also no need to
handle the error IO.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Xiao Ni 143f6e733b md/raid6: Set R5_ReadError when there is read failure on parity disk
7471fb77ce ("md/raid6: Fix anomily when recovering a single device in
RAID6.") avoids rereading P when it can be computed from other members.
However, this misses the chance to re-write the right data to P. This
patch sets R5_ReadError if the re-read fails.

Also, when re-read is skipped, we also missed the chance to reset
rdev->read_errors to 0. It can fail the disk when there are many read
errors on P member disk (other disks don't have read error)

V2: upper layer read request don't read parity/Q data. So there is no
need to consider such situation.

This is Reported-by: kbuild test robot <lkp@intel.com>

Fixes: 7471fb77ce ("md/raid6: Fix anomily when recovering a single device in RAID6.")
Cc: <stable@vger.kernel.org> #4.4+
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Hou Tao 4675719d0f raid1: use an int as the return value of raise_barrier()
Using a sector_t as the return value is misleading, because
raise_barrier() only return 0 or -EINTR.

Also add comments for the return values of raise_barrier().

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
2019-08-07 10:25:02 -07:00
Ming Lei 226b4fc75c blk-mq: add callback of .cleanup_rq
SCSI maintains its own driver private data hooked off of each SCSI
request, and the pridate data won't be freed after scsi_queue_rq()
returns BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE. An upper layer driver
(e.g. dm-rq) may need to retry these SCSI requests, before SCSI has
fully dispatched them, due to a lower level SCSI driver's resource
limitation identified in scsi_queue_rq(). Currently SCSI's per-request
private data is leaked when the upper layer driver (dm-rq) frees and
then retries these requests in response to BLK_STS_RESOURCE or
BLK_STS_DEV_RESOURCE returns from scsi_queue_rq().

This usecase is so specialized that it doesn't warrant training an
existing blk-mq interface (e.g. blk_mq_free_request) to allow SCSI to
account for freeing its driver private data -- doing so would add an
extra branch for handling a special case that all other consumers of
SCSI (and blk-mq) won't ever need to worry about.

So the most pragmatic way forward is to delegate freeing SCSI driver
private data to the upper layer driver (dm-rq).  Do so by adding
new .cleanup_rq callback and calling a new blk_mq_cleanup_rq() method
from dm-rq.  A following commit will implement the .cleanup_rq() hook
in scsi_mq_ops.

Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: <stable@vger.kernel.org>
Fixes: 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-04 21:42:06 -06:00
Mike Snitzer 9c50a98f55 dm table: fix various whitespace issues with recent DAX code
Also, rename device_synchronous to device_dax_synchronous.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-30 18:59:24 -04:00
Pankaj Gupta 5348deb138 dm table: fix dax_dev NULL dereference in device_synchronous()
If a device doesn't support DAX its 'dax_dev' is NULL.  Fix
device_synchronous() to first check if dax_dev is NULL before
dereferencing it.

Fixes: 2e9ee0955d ("dm: enable synchronous dax")
Reported-by: jencce.kernel@gmail.com
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-30 18:58:54 -04:00
Linus Torvalds 0441281965 for-linus-20190726
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Merge tag 'for-linus-20190726' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Several io_uring fixes/improvements:
     - Blocking fix for O_DIRECT (me)
     - Latter page slowness for registered buffers (me)
     - Fix poll hang under certain conditions (me)
     - Defer sequence check fix for wrapped rings (Zhengyuan)
     - Mismatch in async inc/dec accounting (Zhengyuan)
     - Memory ordering issue that could cause stall (Zhengyuan)
      - Track sequential defer in bytes, not pages (Zhengyuan)

 - NVMe pull request from Christoph

 - Set of hang fixes for wbt (Josef)

 - Redundant error message kill for libahci (Ding)

 - Remove unused blk_mq_sched_started_request() and related ops (Marcos)

 - drbd dynamic alloc shash descriptor to reduce stack use (Arnd)

 - blkcg ->pd_stat() non-debug print (Tejun)

 - bcache memory leak fix (Wei)

 - Comment fix (Akinobu)

 - BFQ perf regression fix (Paolo)

* tag 'for-linus-20190726' of git://git.kernel.dk/linux-block: (24 commits)
  io_uring: ensure ->list is initialized for poll commands
  Revert "nvme-pci: don't create a read hctx mapping without read queues"
  nvme: fix multipath crash when ANA is deactivated
  nvme: fix memory leak caused by incorrect subsystem free
  nvme: ignore subnqn for ADATA SX6000LNP
  drbd: dynamically allocate shash descriptor
  block: blk-mq: Remove blk_mq_sched_started_request and started_request
  bcache: fix possible memory leak in bch_cached_dev_run()
  io_uring: track io length in async_list based on bytes
  io_uring: don't use iov_iter_advance() for fixed buffers
  block: properly handle IOCB_NOWAIT for async O_DIRECT IO
  blk-mq: allow REQ_NOWAIT to return an error inline
  io_uring: add a memory barrier before atomic_read
  rq-qos: use a mb for got_token
  rq-qos: set ourself TASK_UNINTERRUPTIBLE after we schedule
  rq-qos: don't reset has_sleepers on spurious wakeups
  rq-qos: fix missed wake-ups in rq_qos_throttle
  wait: add wq_has_single_sleeper helper
  block, bfq: check also in-flight I/O in dispatch plugging
  block: fix sysfs module parameters directory path in comment
  ...
2019-07-26 10:32:12 -07:00
Wei Yongjun 5d9e06d60e bcache: fix possible memory leak in bch_cached_dev_run()
memory malloced in bch_cached_dev_run() and should be freed before
leaving from the error handling cases, otherwise it will cause
memory leak.

Fixes: 0b13efecf5 ("bcache: add return value check to bch_cached_dev_run()")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-22 08:15:17 -06:00
Linus Torvalds 3bfe1fc467 - Fix zone state management race in DM zoned target by eliminating
the unnecessary DMZ_ACTIVE state.
 
 - A couple fixes for issues the DM snapshot target's optional discard
   support added during first week of the 5.3 merge.
 
 - Increase default size of outstanding IO that is allowed for a each
   dm-kcopyd client and introduce tunable to allow user adjust.
 
 - Update DM core to use printk ratelimiting functions rather than
   duplicate them and in doing so fix an issue where DMDEBUG_LIMIT() rate
   limited KERN_DEBUG messages had excessive "callbacks suppressed"
   messages.
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Merge tag 'for-5.3/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull more device mapper updates from Mike Snitzer:

 - Fix zone state management race in DM zoned target by eliminating the
   unnecessary DMZ_ACTIVE state.

 - A couple fixes for issues the DM snapshot target's optional discard
   support added during first week of the 5.3 merge.

 - Increase default size of outstanding IO that is allowed for a each
   dm-kcopyd client and introduce tunable to allow user adjust.

 - Update DM core to use printk ratelimiting functions rather than
   duplicate them and in doing so fix an issue where DMDEBUG_LIMIT()
   rate limited KERN_DEBUG messages had excessive "callbacks suppressed"
   messages.

* tag 'for-5.3/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: use printk ratelimiting functions
  dm kcopyd: Increase default sub-job size to 512KB
  dm snapshot: fix oversights in optional discard support
  dm zoned: fix zone state management race
2019-07-18 14:49:33 -07:00
Linus Torvalds f8c3500cd1 - virtio_pmem: The new virtio_pmem facility introduces a paravirtualized
persistent memory device that allows a guest VM to use DAX mechanisms to
   access a host-file with host-page-cache. It arranges for MAP_SYNC to
   be disabled and instead triggers a host fsync() when a 'write-cache
   flush' command is sent to the virtual disk device.
 
 - Miscellaneous small fixups.
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Merge tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "Primarily just the virtio_pmem driver:

   - virtio_pmem

     The new virtio_pmem facility introduces a paravirtualized
     persistent memory device that allows a guest VM to use DAX
     mechanisms to access a host-file with host-page-cache. It arranges
     for MAP_SYNC to be disabled and instead triggers a host fsync()
     when a 'write-cache flush' command is sent to the virtual disk
     device.

   - Miscellaneous small fixups"

* tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  virtio_pmem: fix sparse warning
  xfs: disable map_sync for async flush
  ext4: disable map_sync for async flush
  dax: check synchronous mapping is supported
  dm: enable synchronous dax
  libnvdimm: add dax_dev sync flag
  virtio-pmem: Add virtio pmem driver
  libnvdimm: nd_region flush callback support
  libnvdimm, namespace: Drop uuid_t implementation detail
2019-07-18 10:52:08 -07:00
Nikos Tsironis c663e04097 dm kcopyd: Increase default sub-job size to 512KB
Currently, kcopyd has a sub-job size of 64KB and a maximum number of 8
sub-jobs. As a result, for any kcopyd job, we have a maximum of 512KB of
I/O in flight.

This upper limit to the amount of in-flight I/O under-utilizes fast
devices and results in decreased throughput, e.g., when writing to a
snapshotted thin LV with I/O size less than the pool's block size (so
COW is performed using kcopyd).

Increase kcopyd's default sub-job size to 512KB, so we have a maximum of
4MB of I/O in flight for each kcopyd job. This results in an up to 96%
improvement of bandwidth when writing to a snapshotted thin LV, with I/O
sizes less than the pool's block size.

Also, add dm_mod.kcopyd_subjob_size_kb module parameter to allow users
to fine tune the sub-job size of kcopyd. The default value of this
parameter is 512KB and the maximum allowed value is 1024KB.

We evaluate the performance impact of the change by running the
snap_breaking_throughput benchmark, from the device mapper test suite
[1].

The benchmark:

  1. Creates a 1G thin LV
  2. Provisions the thin LV
  3. Takes a snapshot of the thin LV
  4. Writes to the thin LV with:

      dd if=/dev/zero of=/dev/vg/thin_lv oflag=direct bs=<I/O size>

Running this benchmark with various thin pool block sizes and dd I/O
sizes (all combinations triggering the use of kcopyd) we get the
following results:

+-----------------+-------------+------------------+-----------------+
| Pool block size | dd I/O size | BW before (MB/s) | BW after (MB/s) |
+-----------------+-------------+------------------+-----------------+
|       1 MB      |      256 KB |       242        |       280       |
|       1 MB      |      512 KB |       238        |       295       |
|                 |             |                  |                 |
|       2 MB      |      256 KB |       238        |       354       |
|       2 MB      |      512 KB |       241        |       380       |
|       2 MB      |        1 MB |       245        |       394       |
|                 |             |                  |                 |
|       4 MB      |      256 KB |       248        |       412       |
|       4 MB      |      512 KB |       234        |       432       |
|       4 MB      |        1 MB |       251        |       474       |
|       4 MB      |        2 MB |       257        |       504       |
|                 |             |                  |                 |
|       8 MB      |      256 KB |       239        |       420       |
|       8 MB      |      512 KB |       256        |       431       |
|       8 MB      |        1 MB |       264        |       467       |
|       8 MB      |        2 MB |       264        |       502       |
|       8 MB      |        4 MB |       281        |       537       |
+-----------------+-------------+------------------+-----------------+

[1] https://github.com/jthornber/device-mapper-test-suite

Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-17 11:24:16 -04:00
Mike Snitzer 3ee25485ba dm snapshot: fix oversights in optional discard support
__find_snapshots_sharing_cow() should always be used with _origins_lock
held so fix snapshot_io_hints() accordingly.  Also, once a snapshot is
being merged discards must not be allowed -- otherwise incorrect or
duplicate work will be performed.

Fixes: 2e6023850e ("dm snapshot: add optional discard support features")
Reported-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-17 11:12:30 -04:00
Damien Le Moal 3b8cafdd54 dm zoned: fix zone state management race
dm-zoned uses the zone flag DMZ_ACTIVE to indicate that a zone of the
backend device is being actively read or written and so cannot be
reclaimed. This flag is set as long as the zone atomic reference
counter is not 0. When this atomic is decremented and reaches 0 (e.g.
on BIO completion), the active flag is cleared and set again whenever
the zone is reused and BIO issued with the atomic counter incremented.
These 2 operations (atomic inc/dec and flag set/clear) are however not
always executed atomically under the target metadata mutex lock and
this causes the warning:

WARN_ON(!test_bit(DMZ_ACTIVE, &zone->flags));

in dmz_deactivate_zone() to be displayed. This problem is regularly
triggered with xfstests generic/209, generic/300, generic/451 and
xfs/077 with XFS being used as the file system on the dm-zoned target
device. Similarly, xfstests ext4/303, ext4/304, generic/209 and
generic/300 trigger the warning with ext4 use.

This problem can be easily fixed by simply removing the DMZ_ACTIVE flag
and managing the "ACTIVE" state by directly looking at the reference
counter value. To do so, the functions dmz_activate_zone() and
dmz_deactivate_zone() are changed to inline functions respectively
calling atomic_inc() and atomic_dec(), while the dmz_is_active() macro
is changed to an inline function calling atomic_read().

Fixes: 3b1a94c88b ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Reported-by: Masato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-17 11:03:48 -04:00
Linus Torvalds c309b6f242 docs conversion for v5.3-rc1
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Merge tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull rst conversion of docs from Mauro Carvalho Chehab:
 "As agreed with Jon, I'm sending this big series directly to you, c/c
  him, as this series required a special care, in order to avoid
  conflicts with other trees"

* tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits)
  docs: kbuild: fix build with pdf and fix some minor issues
  docs: block: fix pdf output
  docs: arm: fix a breakage with pdf output
  docs: don't use nested tables
  docs: gpio: add sysfs interface to the admin-guide
  docs: locking: add it to the main index
  docs: add some directories to the main documentation index
  docs: add SPDX tags to new index files
  docs: add a memory-devices subdir to driver-api
  docs: phy: place documentation under driver-api
  docs: serial: move it to the driver-api
  docs: driver-api: add remaining converted dirs to it
  docs: driver-api: add xilinx driver API documentation
  docs: driver-api: add a series of orphaned documents
  docs: admin-guide: add a series of orphaned documents
  docs: cgroup-v1: add it to the admin-guide book
  docs: aoe: add it to the driver-api book
  docs: add some documentation dirs to the driver-api book
  docs: driver-model: move it to the driver-api book
  docs: lp855x-driver.rst: add it to the driver-api book
  ...
2019-07-16 12:21:41 -07:00
Linus Torvalds 9637d51734 for-linus-20190715
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Merge tag 'for-linus-20190715' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "A later pull request with some followup items. I had some vacation
  coming up to the merge window, so certain things items were delayed a
  bit. This pull request also contains fixes that came in within the
  last few days of the merge window, which I didn't want to push right
  before sending you a pull request.

  This contains:

   - NVMe pull request, mostly fixes, but also a few minor items on the
     feature side that were timing constrained (Christoph et al)

   - Report zones fixes (Damien)

   - Removal of dead code (Damien)

   - Turn on cgroup psi memstall (Josef)

   - block cgroup MAINTAINERS entry (Konstantin)

   - Flush init fix (Josef)

   - blk-throttle low iops timing fix (Konstantin)

   - nbd resize fixes (Mike)

   - nbd 0 blocksize crash fix (Xiubo)

   - block integrity error leak fix (Wenwen)

   - blk-cgroup writeback and priority inheritance fixes (Tejun)"

* tag 'for-linus-20190715' of git://git.kernel.dk/linux-block: (42 commits)
  MAINTAINERS: add entry for block io cgroup
  null_blk: fixup ->report_zones() for !CONFIG_BLK_DEV_ZONED
  block: Limit zone array allocation size
  sd_zbc: Fix report zones buffer allocation
  block: Kill gfp_t argument of blkdev_report_zones()
  block: Allow mapping of vmalloc-ed buffers
  block/bio-integrity: fix a memory leak bug
  nvme: fix NULL deref for fabrics options
  nbd: add netlink reconfigure resize support
  nbd: fix crash when the blksize is zero
  block: Disable write plugging for zoned block devices
  block: Fix elevator name declaration
  block: Remove unused definitions
  nvme: fix regression upon hot device removal and insertion
  blk-throttle: fix zero wait time for iops throttled group
  block: Fix potential overflow in blk_report_zones()
  blkcg: implement REQ_CGROUP_PUNT
  blkcg, writeback: Implement wbc_blkcg_css()
  blkcg, writeback: Add wbc->no_cgroup_owner
  blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner()
  ...
2019-07-15 21:20:52 -07:00
Mauro Carvalho Chehab 6cf2a73cb2 docs: device-mapper: move it to the admin-guide
The DM support describes lots of aspects related to mapped
disk partitions from the userspace PoV.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15 11:03:01 -03:00
Linus Torvalds a1240cf74e Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu updates from Dennis Zhou:
 "This includes changes to let percpu_ref release the backing percpu
  memory earlier after it has been switched to atomic in cases where the
  percpu ref is not revived.

  This will help recycle percpu memory earlier in cases where the
  refcounts are pinned for prolonged periods of time"

* 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu_ref: release percpu memory early without PERCPU_REF_ALLOW_REINIT
  md: initialize percpu refcounters using PERCU_REF_ALLOW_REINIT
  io_uring: initialize percpu refcounters using PERCU_REF_ALLOW_REINIT
  percpu_ref: introduce PERCPU_REF_ALLOW_REINIT flag
2019-07-14 16:17:18 -07:00
Linus Torvalds 2260840592 - Add encrypted byte-offset initialization vector (eboiv) to DM crypt.
- Add optional discard features to DM snapshot which allow freeing space
   from a DM device whose free space was exhausted.
 
 - Various small improvements to use struct_size() and kzalloc().
 
 - Fix to check if DM thin metadata is in fail_io mode before attempting
   to update the superblock to set the needs_check flag.  Otherwise the
   DM thin-pool can hang.
 
 - Fix DM bufio shrinker's potential for ABBA recursion deadlock with DM
   thin provisioning on loop usecase.
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Merge tag 'for-5.3/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Add encrypted byte-offset initialization vector (eboiv) to DM crypt.

 - Add optional discard features to DM snapshot which allow freeing
   space from a DM device whose free space was exhausted.

 - Various small improvements to use struct_size() and kzalloc().

 - Fix to check if DM thin metadata is in fail_io mode before attempting
   to update the superblock to set the needs_check flag. Otherwise the
   DM thin-pool can hang.

 - Fix DM bufio shrinker's potential for ABBA recursion deadlock with DM
   thin provisioning on loop usecase.

* tag 'for-5.3/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: fix deadlock with loop device
  dm snapshot: add optional discard support features
  dm crypt: implement eboiv - encrypted byte-offset initialization vector
  dm crypt: remove obsolete comment about plumb IV
  dm crypt: wipe private IV struct after key invalid flag is set
  dm integrity: use kzalloc() instead of kmalloc() + memset()
  dm: update stale comment in end_clone_bio()
  dm log writes: fix incorrect comment about the logged sequence example
  dm log writes: use struct_size() to calculate size of pending_block
  dm crypt: use struct_size() when allocating encryption context
  dm integrity: always set version on superblock update
  dm thin metadata: check if in fail_io mode when setting needs_check
2019-07-13 15:24:31 -07:00
Junxiao Bi bd293d071f dm bufio: fix deadlock with loop device
When thin-volume is built on loop device, if available memory is low,
the following deadlock can be triggered:

One process P1 allocates memory with GFP_FS flag, direct alloc fails,
memory reclaim invokes memory shrinker in dm_bufio, dm_bufio_shrink_scan()
runs, mutex dm_bufio_client->lock is acquired, then P1 waits for dm_buffer
IO to complete in __try_evict_buffer().

But this IO may never complete if issued to an underlying loop device
that forwards it using direct-IO, which allocates memory using
GFP_KERNEL (see: do_blockdev_direct_IO()).  If allocation fails, memory
reclaim will invoke memory shrinker in dm_bufio, dm_bufio_shrink_scan()
will be invoked, and since the mutex is already held by P1 the loop
thread will hang, and IO will never complete.  Resulting in ABBA
deadlock.

Cc: stable@vger.kernel.org
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-12 09:59:37 -04:00
Mike Snitzer 2e6023850e dm snapshot: add optional discard support features
discard_zeroes_cow - a discard issued to the snapshot device that maps
to entire chunks to will zero the corresponding exception(s) in the
snapshot's exception store.

discard_passdown_origin - a discard to the snapshot device is passed down
to the snapshot-origin's underlying device.  This doesn't cause copy-out
to the snapshot exception store because the snapshot-origin target is
bypassed.

The discard_passdown_origin feature depends on the discard_zeroes_cow
feature being enabled.

When these 2 features are enabled they allow a temporarily read-only
device that has completely exhausted its free space to recover space.
To do so dm-snapshot provides temporary buffer to accommodate writes
that the temporarily read-only device cannot handle yet.  Once the upper
layer frees space (e.g. fstrim to XFS) the discards issued to the
dm-snapshot target will be issued to underlying read-only device whose
free space was exhausted.  In addition those discards will also cause
zeroes to be written to the snapshot exception store if corresponding
exceptions exist.  If the underlying origin device provides
deduplication for zero blocks then if/when the snapshot is merged backed
to the origin those blocks will become unused.  Once the origin has
gained adequate space, merging the snapshot back to the thinly
provisioned device will permit continued use of that device without the
temporary space provided by the snapshot.

Requested-by: John Dorminy <jdorminy@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-12 09:59:36 -04:00
Damien Le Moal bd976e5272 block: Kill gfp_t argument of blkdev_report_zones()
Only GFP_KERNEL and GFP_NOIO are used with blkdev_report_zones(). In
preparation of using vmalloc() for large report buffer and zone array
allocations used by this function, remove its "gfp_t gfp_mask" argument
and rely on the caller context to use memalloc_noio_save/restore() where
necessary (block layer zone revalidation and dm-zoned I/O error path).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-11 20:04:37 -06:00
Linus Torvalds 028db3e290 Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"
This reverts merge 0f75ef6a9c (and thus
effectively commits

   7a1ade8475 ("keys: Provide KEYCTL_GRANT_PERMISSION")
   2e12256b9a ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

 [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
 [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-10 18:43:43 -07:00
Linus Torvalds e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Milan Broz b9411d73bd dm crypt: implement eboiv - encrypted byte-offset initialization vector
This IV is used in some BitLocker devices with CBC encryption mode.

IV is encrypted little-endian byte-offset (with the same key and cipher
as the volume).

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:14:23 -04:00
Milan Broz 6028a7a5a3 dm crypt: remove obsolete comment about plumb IV
The URL is no longer valid and the comment is obsolete anyway
(the plumb IV was never used).

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:14:22 -04:00
Milan Broz 4a52ffc7ca dm crypt: wipe private IV struct after key invalid flag is set
If a private IV wipe function fails, the code does not set the key
invalid flag.  To fix this, move code to after the flag is set to
prevent the device from resuming in an inconsistent state.

Also, this allows using of a randomized key in private wipe function
(to be used in a following commit).

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:14:21 -04:00
Fuqian Huang 131670c262 dm integrity: use kzalloc() instead of kmalloc() + memset()
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:14:20 -04:00
Pavel Begunkov d370ad23a5 dm: update stale comment in end_clone_bio()
Since commit a1ce35fa49 ("block: remove dead elevator
code") blk_end_request() has been replaced with blk_mq_end_request().
So update comment to reference blk_mq_end_request() accordingly.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:14:20 -04:00
Qu Wenruo 7537dad791 dm log writes: fix incorrect comment about the logged sequence example
dm-log-writes records the sequence of completion, not submission, thus
for the following sequence (W=write, C=complete):

  Wa,Wb,Wc,Cc,Ca,FLUSH,FUAd,Cb,CFLUSH,CFUAd

The logged results in log device should be:
  c,a,b,flush,fua

Fix the comment to give a better example.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:13:33 -04:00
Zhengyuan Liu d4e6e83651 dm log writes: use struct_size() to calculate size of pending_block
Use struct_size() to avoid open-coded equivalent that is prone to a type
mistake.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:08:41 -04:00
Zhengyuan Liu 9c81c99b24 dm crypt: use struct_size() when allocating encryption context
Use struct_size() to avoid open-coded equivalent that is prone to a type
mistake.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 14:08:40 -04:00
Milan Broz 5f1c56b34e dm integrity: always set version on superblock update
The new integrity bitmap mode uses the dirty flag.  The dirty flag
should not be set in older superblock versions.

The current code sets it unconditionally, even if the superblock
was already formatted without bitmap in older system.

Fix this by moving the version check to one common place and check
version on every superblock write.

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-09 13:46:01 -04:00
Linus Torvalds 3b99107f0e for-5.3/block-20190708
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Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "This is the main block updates for 5.3. Nothing earth shattering or
  major in here, just fixes, additions, and improvements all over the
  map. This contains:

   - Series of documentation fixes (Bart)

   - Optimization of the blk-mq ctx get/put (Bart)

   - null_blk removal race condition fix (Bob)

   - req/bio_op() cleanups (Chaitanya)

   - Series cleaning up the segment accounting, and request/bio mapping
     (Christoph)

   - Series cleaning up the page getting/putting for bios (Christoph)

   - block cgroup cleanups and moving it to where it is used (Christoph)

   - block cgroup fixes (Tejun)

   - Series of fixes and improvements to bcache, most notably a write
     deadlock fix (Coly)

   - blk-iolatency STS_AGAIN and accounting fixes (Dennis)

   - Series of improvements and fixes to BFQ (Douglas, Paolo)

   - debugfs_create() return value check removal for drbd (Greg)

   - Use struct_size(), where appropriate (Gustavo)

   - Two lighnvm fixes (Heiner, Geert)

   - MD fixes, including a read balance and corruption fix (Guoqing,
     Marcos, Xiao, Yufen)

   - block opal shadow mbr additions (Jonas, Revanth)

   - sbitmap compare-and-exhange improvemnts (Pavel)

   - Fix for potential bio->bi_size overflow (Ming)

   - NVMe pull requests:
       - improved PCIe suspent support (Keith Busch)
       - error injection support for the admin queue (Akinobu Mita)
       - Fibre Channel discovery improvements (James Smart)
       - tracing improvements including nvmetc tracing support (Minwoo Im)
       - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya
         Kulkarni)"

   - Various little fixes and improvements to drivers and core"

* tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits)
  blk-iolatency: fix STS_AGAIN handling
  block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES
  blk-mq: simplify blk_mq_make_request()
  blk-mq: remove blk_mq_put_ctx()
  sbitmap: Replace cmpxchg with xchg
  block: fix .bi_size overflow
  block: sed-opal: check size of shadow mbr
  block: sed-opal: ioctl for writing to shadow mbr
  block: sed-opal: add ioctl for done-mark of shadow mbr
  block: never take page references for ITER_BVEC
  direct-io: use bio_release_pages in dio_bio_complete
  block_dev: use bio_release_pages in bio_unmap_user
  block_dev: use bio_release_pages in blkdev_bio_end_io
  iomap: use bio_release_pages in iomap_dio_bio_end_io
  block: use bio_release_pages in bio_map_user_iov
  block: use bio_release_pages in bio_unmap_user
  block: optionally mark pages dirty in bio_release_pages
  block: move the BIO_NO_PAGE_REF check into bio_release_pages
  block: skd_main.c: Remove call to memset after dma_alloc_coherent
  block: mtip32xx: Remove call to memset after dma_alloc_coherent
  ...
2019-07-09 10:45:06 -07:00
Linus Torvalds 0f75ef6a9c Keyrings ACL
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Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull keyring ACL support from David Howells:
 "This changes the permissions model used by keys and keyrings to be
  based on an internal ACL by the following means:

   - Replace the permissions mask internally with an ACL that contains a
     list of ACEs, each with a specific subject with a permissions mask.
     Potted default ACLs are available for new keys and keyrings.

     ACE subjects can be macroised to indicate the UID and GID specified
     on the key (which remain). Future commits will be able to add
     additional subject types, such as specific UIDs or domain
     tags/namespaces.

     Also split a number of permissions to give finer control. Examples
     include splitting the revocation permit from the change-attributes
     permit, thereby allowing someone to be granted permission to revoke
     a key without allowing them to change the owner; also the ability
     to join a keyring is split from the ability to link to it, thereby
     stopping a process accessing a keyring by joining it and thus
     acquiring use of possessor permits.

   - Provide a keyctl to allow the granting or denial of one or more
     permits to a specific subject. Direct access to the ACL is not
     granted, and the ACL cannot be viewed"

* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  keys: Provide KEYCTL_GRANT_PERMISSION
  keys: Replace uid/gid/perm permissions checking with an ACL
2019-07-08 19:56:57 -07:00
Pankaj Gupta 2e9ee0955d dm: enable synchronous dax
This patch sets dax device 'DAXDEV_SYNC' flag if all the target
devices of device mapper support synchrononous DAX. If device
mapper consists of both synchronous and asynchronous dax devices,
we don't set 'DAXDEV_SYNC' flag.

'dm_table_supports_dax' is refactored to pass 'iterate_devices_fn'
as argument so that the callers can pass the appropriate functions.

Suggested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05 15:19:10 -07:00
Pankaj Gupta fefc1d97fa libnvdimm: add dax_dev sync flag
This patch adds 'DAXDEV_SYNC' flag which is set
for nd_region doing synchronous flush. This later
is used to disable MAP_SYNC functionality for
ext4 & xfs filesystem for devices don't support
synchronous flush.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-07-05 15:19:10 -07:00
Mike Snitzer 54fa16ee53 dm thin metadata: check if in fail_io mode when setting needs_check
Check if in fail_io mode at start of dm_pool_metadata_set_needs_check().
Otherwise dm_pool_metadata_set_needs_check()'s superblock_lock() can
crash in dm_bm_write_lock() while accessing the block manager object
that was previously destroyed as part of a failed
dm_pool_abort_metadata() that ultimately set fail_io to begin with.

Also, update DMERR() message to more accurately describe
superblock_lock() failure.

Cc: stable@vger.kernel.org
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-02 15:50:08 -04:00
Jens Axboe 5be1f9d82f Linux 5.2-rc6
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Merge tag 'v5.2-rc6' into for-5.3/block

Merge 5.2-rc6 into for-5.3/block, so we get the same page merge leak
fix. Otherwise we end up having conflicts with future patches between
for-5.3/block and master that touch this area. In particular, it makes
the bio_full() fix hard to backport to stable.

* tag 'v5.2-rc6': (482 commits)
  Linux 5.2-rc6
  Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock"
  Bluetooth: Fix regression with minimum encryption key size alignment
  tcp: refine memory limit test in tcp_fragment()
  x86/vdso: Prevent segfaults due to hoisted vclock reads
  SUNRPC: Fix a credential refcount leak
  Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE"
  net :sunrpc :clnt :Fix xps refcount imbalance on the error path
  NFS4: Only set creation opendata if O_CREAT
  ARM: 8867/1: vdso: pass --be8 to linker if necessary
  KVM: nVMX: reorganize initial steps of vmx_set_nested_state
  KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries
  habanalabs: use u64_to_user_ptr() for reading user pointers
  nfsd: replace Jeff by Chuck as nfsd co-maintainer
  inet: clear num_timeout reqsk_alloc()
  PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present
  net: mvpp2: debugfs: Add pmap to fs dump
  ipv6: Default fib6_type to RTN_UNICAST when not set
  net: hns3: Fix inconsistent indenting
  net/af_iucv: always register net_device notifier
  ...
2019-07-01 08:16:08 -06:00
Coly Li dff90d58a1 bcache: add reclaimed_journal_buckets to struct cache_set
Now we have counters for how many times jouranl is reclaimed, how many
times cached dirty btree nodes are flushed, but we don't know how many
jouranl buckets are really reclaimed.

This patch adds reclaimed_journal_buckets into struct cache_set, this
is an increasing only counter, to tell how many journal buckets are
reclaimed since cache set runs. From all these three counters (reclaim,
reclaimed_journal_buckets, flush_write), we can have idea how well
current journal space reclaim code works.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:18 -06:00
Coly Li 91be66e131 bcache: performance improvement for btree_flush_write()
This patch improves performance for btree_flush_write() in following
ways,
- Use another spinlock journal.flush_write_lock to replace the very
  hot journal.lock. We don't have to use journal.lock here, selecting
  candidate btree nodes takes a lot of time, hold journal.lock here will
  block other jouranling threads and drop the overall I/O performance.
- Only select flushing btree node from c->btree_cache list. When the
  machine has a large system memory, mca cache may have a huge number of
  cached btree nodes. Iterating all the cached nodes will take a lot
  of CPU time, and most of the nodes on c->btree_cache_freeable and
  c->btree_cache_freed lists are cleared and have need to flush. So only
  travel mca list c->btree_cache to select flushing btree node should be
  enough for most of the cases.
- Don't iterate whole c->btree_cache list, only reversely select first
  BTREE_FLUSH_NR btree nodes to flush. Iterate all btree nodes from
  c->btree_cache and select the oldest journal pin btree nodes consumes
  huge number of CPU cycles if the list is huge (push and pop a node
  into/out of a heap is expensive). The last several dirty btree nodes
  on the tail of c->btree_cache list are earlest allocated and cached
  btree nodes, they are relative to the oldest journal pin btree nodes.
  Therefore only flushing BTREE_FLUSH_NR btree nodes from tail of
  c->btree_cache probably includes the oldest journal pin btree nodes.

In my testing, the above change decreases 50%+ CPU consumption when
journal space is full. Some times IOPS drops to 0 for 5-8 seconds,
comparing blocking I/O for 120+ seconds in previous code, this is much
better. Maybe there is room to improve in future, but at this momment
the fix looks fine and performs well in my testing.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:18 -06:00
Coly Li 50a260e859 bcache: fix race in btree_flush_write()
There is a race between mca_reap(), btree_node_free() and journal code
btree_flush_write(), which results very rare and strange deadlock or
panic and are very hard to reproduce.

Let me explain how the race happens. In btree_flush_write() one btree
node with oldest journal pin is selected, then it is flushed to cache
device, the select-and-flush is a two steps operation. Between these two
steps, there are something may happen inside the race window,
- The selected btree node was reaped by mca_reap() and allocated to
  other requesters for other btree node.
- The slected btree node was selected, flushed and released by mca
  shrink callback bch_mca_scan().
When btree_flush_write() tries to flush the selected btree node, firstly
b->write_lock is held by mutex_lock(). If the race happens and the
memory of selected btree node is allocated to other btree node, if that
btree node's write_lock is held already, a deadlock very probably
happens here. A worse case is the memory of the selected btree node is
released, then all references to this btree node (e.g. b->write_lock)
will trigger NULL pointer deference panic.

This race was introduced in commit cafe563591 ("bcache: A block layer
cache"), and enlarged by commit c4dc2497d5 ("bcache: fix high CPU
occupancy during journal"), which selected 128 btree nodes and flushed
them one-by-one in a quite long time period.

Such race is not easy to reproduce before. On a Lenovo SR650 server with
48 Xeon cores, and configure 1 NVMe SSD as cache device, a MD raid0
device assembled by 3 NVMe SSDs as backing device, this race can be
observed around every 10,000 times btree_flush_write() gets called. Both
deadlock and kernel panic all happened as aftermath of the race.

The idea of the fix is to add a btree flag BTREE_NODE_journal_flush. It
is set when selecting btree nodes, and cleared after btree nodes
flushed. Then when mca_reap() selects a btree node with this bit set,
this btree node will be skipped. Since mca_reap() only reaps btree node
without BTREE_NODE_journal_flush flag, such race is avoided.

Once corner case should be noticed, that is btree_node_free(). It might
be called in some error handling code path. For example the following
code piece from btree_split(),
        2149 err_free2:
        2150         bkey_put(b->c, &n2->key);
        2151         btree_node_free(n2);
        2152         rw_unlock(true, n2);
        2153 err_free1:
        2154         bkey_put(b->c, &n1->key);
        2155         btree_node_free(n1);
        2156         rw_unlock(true, n1);
At line 2151 and 2155, the btree node n2 and n1 are released without
mac_reap(), so BTREE_NODE_journal_flush also needs to be checked here.
If btree_node_free() is called directly in such error handling path,
and the selected btree node has BTREE_NODE_journal_flush bit set, just
delay for 1 us and retry again. In this case this btree node won't
be skipped, just retry until the BTREE_NODE_journal_flush bit cleared,
and free the btree node memory.

Fixes: cafe563591 ("bcache: A block layer cache")
Signed-off-by: Coly Li <colyli@suse.de>
Reported-and-tested-by: kbuild test robot <lkp@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:18 -06:00
Coly Li d91ce7574d bcache: remove retry_flush_write from struct cache_set
In struct cache_set, retry_flush_write is added for commit c4dc2497d5
("bcache: fix high CPU occupancy during journal") which is reverted in
previous patch.

Now it is useless anymore, and this patch removes it from bcache code.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:18 -06:00
Coly Li 41508bb7d4 bcache: add comments for mutex_lock(&b->write_lock)
When accessing or modifying BTREE_NODE_dirty bit, it is not always
necessary to acquire b->write_lock. In bch_btree_cache_free() and
mca_reap() acquiring b->write_lock is necessary, and this patch adds
comments to explain why mutex_lock(&b->write_lock) is necessary for
checking or clearing BTREE_NODE_dirty bit there.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li e5ec5f4765 bcache: only clear BTREE_NODE_dirty bit when it is set
In bch_btree_cache_free() and btree_node_free(), BTREE_NODE_dirty is
always set no matter btree node is dirty or not. The code looks like
this,
	if (btree_node_dirty(b))
		btree_complete_write(b, btree_current_write(b));
	clear_bit(BTREE_NODE_dirty, &b->flags);

Indeed if btree_node_dirty(b) returns false, it means BTREE_NODE_dirty
bit is cleared, then it is unnecessary to clear the bit again.

This patch only clears BTREE_NODE_dirty when btree_node_dirty(b) is
true (the bit is set), to save a few CPU cycles.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li 249a5f6da5 bcache: Revert "bcache: fix high CPU occupancy during journal"
This reverts commit c4dc2497d5.

This patch enlarges a race between normal btree flush code path and
flush_btree_write(), which causes deadlock when journal space is
exhausted. Reverts this patch makes the race window from 128 btree
nodes to only 1 btree nodes.

Fixes: c4dc2497d5 ("bcache: fix high CPU occupancy during journal")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Tang Junhui <tang.junhui.linux@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li ba82c1ac16 bcache: Revert "bcache: free heap cache_set->flush_btree in bch_journal_free"
This reverts commit 6268dc2c47.

This patch depends on commit c4dc2497d5 ("bcache: fix high CPU
occupancy during journal") which is reverted in previous patch. So
revert this one too.

Fixes: 6268dc2c47 ("bcache: free heap cache_set->flush_btree in bch_journal_free")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Shenghui Wang <shhuiw@foxmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li 1df3877ff6 bcache: shrink btree node cache after bch_btree_check()
When cache set starts, bch_btree_check() will check all bkeys on cache
device by calculating the checksum. This operation will consume a huge
number of system memory if there are a lot of data cached. Since bcache
uses its own mca cache to maintain all its read-in btree nodes, and only
releases the cache space when system memory manage code starts to shrink
caches. Then before memory manager code to call the mca cache shrinker
callback, bcache mca cache will compete memory resource with user space
application, which may have nagive effect to performance of user space
workloads (e.g. data base, or I/O service of distributed storage node).

This patch tries to call bcache mca shrinker routine to proactively
release mca cache memory, to decrease the memory pressure of system and
avoid negative effort of the overall system I/O performance.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li a231f07a5f bcache: set largest seq to ja->seq[bucket_index] in journal_read_bucket()
In journal_read_bucket() when setting ja->seq[bucket_index], there might
be potential case that a later non-maximum overwrites a better sequence
number to ja->seq[bucket_index]. This patch adds a check to make sure
that ja->seq[bucket_index] will be only set a new value if it is bigger
then current value.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li 2464b69314 bcache: add code comments for journal_read_bucket()
This patch adds more code comments in journal_read_bucket(), this is an
effort to make the code to be more understandable.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:17 -06:00
Coly Li 7e865eba00 bcache: fix potential deadlock in cached_def_free()
When enable lockdep and reboot system with a writeback mode bcache
device, the following potential deadlock warning is reported by lockdep
engine.

[  101.536569][  T401] kworker/2:2/401 is trying to acquire lock:
[  101.538575][  T401] 00000000bbf6e6c7 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0
[  101.542054][  T401]
[  101.542054][  T401] but task is already holding lock:
[  101.544587][  T401] 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[  101.548386][  T401]
[  101.548386][  T401] which lock already depends on the new lock.
[  101.548386][  T401]
[  101.551874][  T401]
[  101.551874][  T401] the existing dependency chain (in reverse order) is:
[  101.555000][  T401]
[  101.555000][  T401] -> #1 ((work_completion)(&cl->work)#2){+.+.}:
[  101.557860][  T401]        process_one_work+0x277/0x640
[  101.559661][  T401]        worker_thread+0x39/0x3f0
[  101.561340][  T401]        kthread+0x125/0x140
[  101.562963][  T401]        ret_from_fork+0x3a/0x50
[  101.564718][  T401]
[  101.564718][  T401] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}:
[  101.567701][  T401]        lock_acquire+0xb4/0x1c0
[  101.569651][  T401]        flush_workqueue+0xae/0x4c0
[  101.571494][  T401]        drain_workqueue+0xa9/0x180
[  101.573234][  T401]        destroy_workqueue+0x17/0x250
[  101.575109][  T401]        cached_dev_free+0x44/0x120 [bcache]
[  101.577304][  T401]        process_one_work+0x2a4/0x640
[  101.579357][  T401]        worker_thread+0x39/0x3f0
[  101.581055][  T401]        kthread+0x125/0x140
[  101.582709][  T401]        ret_from_fork+0x3a/0x50
[  101.584592][  T401]
[  101.584592][  T401] other info that might help us debug this:
[  101.584592][  T401]
[  101.588355][  T401]  Possible unsafe locking scenario:
[  101.588355][  T401]
[  101.590974][  T401]        CPU0                    CPU1
[  101.592889][  T401]        ----                    ----
[  101.594743][  T401]   lock((work_completion)(&cl->work)#2);
[  101.596785][  T401]                                lock((wq_completion)bcache_writeback_wq);
[  101.600072][  T401]                                lock((work_completion)(&cl->work)#2);
[  101.602971][  T401]   lock((wq_completion)bcache_writeback_wq);
[  101.605255][  T401]
[  101.605255][  T401]  *** DEADLOCK ***
[  101.605255][  T401]
[  101.608310][  T401] 2 locks held by kworker/2:2/401:
[  101.610208][  T401]  #0: 00000000cf2c7d17 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640
[  101.613709][  T401]  #1: 00000000f5f305b3 ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[  101.617480][  T401]
[  101.617480][  T401] stack backtrace:
[  101.619539][  T401] CPU: 2 PID: 401 Comm: kworker/2:2 Tainted: G        W         5.2.0-rc4-lp151.20-default+ #1
[  101.623225][  T401] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[  101.627210][  T401] Workqueue: events cached_dev_free [bcache]
[  101.629239][  T401] Call Trace:
[  101.630360][  T401]  dump_stack+0x85/0xcb
[  101.631777][  T401]  print_circular_bug+0x19a/0x1f0
[  101.633485][  T401]  __lock_acquire+0x16cd/0x1850
[  101.635184][  T401]  ? __lock_acquire+0x6a8/0x1850
[  101.636863][  T401]  ? lock_acquire+0xb4/0x1c0
[  101.638421][  T401]  ? find_held_lock+0x34/0xa0
[  101.640015][  T401]  lock_acquire+0xb4/0x1c0
[  101.641513][  T401]  ? flush_workqueue+0x87/0x4c0
[  101.643248][  T401]  flush_workqueue+0xae/0x4c0
[  101.644832][  T401]  ? flush_workqueue+0x87/0x4c0
[  101.646476][  T401]  ? drain_workqueue+0xa9/0x180
[  101.648303][  T401]  drain_workqueue+0xa9/0x180
[  101.649867][  T401]  destroy_workqueue+0x17/0x250
[  101.651503][  T401]  cached_dev_free+0x44/0x120 [bcache]
[  101.653328][  T401]  process_one_work+0x2a4/0x640
[  101.655029][  T401]  worker_thread+0x39/0x3f0
[  101.656693][  T401]  ? process_one_work+0x640/0x640
[  101.658501][  T401]  kthread+0x125/0x140
[  101.660012][  T401]  ? kthread_create_worker_on_cpu+0x70/0x70
[  101.661985][  T401]  ret_from_fork+0x3a/0x50
[  101.691318][  T401] bcache: bcache_device_free() bcache0 stopped

Here is how the above potential deadlock may happen in reboot/shutdown
code path,
1) bcache_reboot() is called firstly in the reboot/shutdown code path,
   then in bcache_reboot(), bcache_device_stop() is called.
2) bcache_device_stop() sets BCACHE_DEV_CLOSING on d->falgs, then call
   closure_queue(&d->cl) to invoke cached_dev_flush(). And in turn
   cached_dev_flush() calls cached_dev_free() via closure_at()
3) In cached_dev_free(), after stopped writebach kthread
   dc->writeback_thread, the kwork dc->writeback_write_wq is stopping by
   destroy_workqueue().
4) Inside destroy_workqueue(), drain_workqueue() is called. Inside
   drain_workqueue(), flush_workqueue() is called. Then wq->lockdep_map
   is acquired by lock_map_acquire() in flush_workqueue(). After the
   lock acquired the rest part of flush_workqueue() just wait for the
   workqueue to complete.
5) Now we look back at writeback thread routine bch_writeback_thread(),
   in the main while-loop, write_dirty() is called via continue_at() in
   read_dirty_submit(), which is called via continue_at() in while-loop
   level called function read_dirty(). Inside write_dirty() it may be
   re-called on workqueeu dc->writeback_write_wq via continue_at().
   It means when the writeback kthread is stopped in cached_dev_free()
   there might be still one kworker queued on dc->writeback_write_wq
   to execute write_dirty() again.
6) Now this kworker is scheduled on dc->writeback_write_wq to run by
   process_one_work() (which is called by worker_thread()). Before
   calling the kwork routine, wq->lockdep_map is acquired.
7) But wq->lockdep_map is acquired already in step 4), so a A-A lock
   (lockdep terminology) scenario happens.

Indeed on multiple cores syatem, the above deadlock is very rare to
happen, just as the code comments in process_one_work() says,
2263     * AFAICT there is no possible deadlock scenario between the
2264     * flush_work() and complete() primitives (except for
	   single-threaded
2265     * workqueues), so hiding them isn't a problem.

But it is still good to fix such lockdep warning, even no one running
bcache on single core system.

The fix is simple. This patch solves the above potential deadlock by,
- Do not destroy workqueue dc->writeback_write_wq in cached_dev_free().
- Flush and destroy dc->writeback_write_wq in writebach kthread routine
  bch_writeback_thread(), where after quit the thread main while-loop
  and before cached_dev_put() is called.

By this fix, dc->writeback_write_wq will be stopped and destroy before
the writeback kthread stopped, so the chance for a A-A locking on
wq->lockdep_map is disappeared, such A-A deadlock won't happen
any more.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li 80265d8dfd bcache: acquire bch_register_lock later in cached_dev_free()
When enable lockdep engine, a lockdep warning can be observed when
reboot or shutdown system,

[ 3142.764557][    T1] bcache: bcache_reboot() Stopping all devices:
[ 3142.776265][ T2649]
[ 3142.777159][ T2649] ======================================================
[ 3142.780039][ T2649] WARNING: possible circular locking dependency detected
[ 3142.782869][ T2649] 5.2.0-rc4-lp151.20-default+ #1 Tainted: G        W
[ 3142.785684][ T2649] ------------------------------------------------------
[ 3142.788479][ T2649] kworker/3:67/2649 is trying to acquire lock:
[ 3142.790738][ T2649] 00000000aaf02291 ((wq_completion)bcache_writeback_wq){+.+.}, at: flush_workqueue+0x87/0x4c0
[ 3142.794678][ T2649]
[ 3142.794678][ T2649] but task is already holding lock:
[ 3142.797402][ T2649] 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache]
[ 3142.801462][ T2649]
[ 3142.801462][ T2649] which lock already depends on the new lock.
[ 3142.801462][ T2649]
[ 3142.805277][ T2649]
[ 3142.805277][ T2649] the existing dependency chain (in reverse order) is:
[ 3142.808902][ T2649]
[ 3142.808902][ T2649] -> #2 (&bch_register_lock){+.+.}:
[ 3142.812396][ T2649]        __mutex_lock+0x7a/0x9d0
[ 3142.814184][ T2649]        cached_dev_free+0x17/0x120 [bcache]
[ 3142.816415][ T2649]        process_one_work+0x2a4/0x640
[ 3142.818413][ T2649]        worker_thread+0x39/0x3f0
[ 3142.820276][ T2649]        kthread+0x125/0x140
[ 3142.822061][ T2649]        ret_from_fork+0x3a/0x50
[ 3142.823965][ T2649]
[ 3142.823965][ T2649] -> #1 ((work_completion)(&cl->work)#2){+.+.}:
[ 3142.827244][ T2649]        process_one_work+0x277/0x640
[ 3142.829160][ T2649]        worker_thread+0x39/0x3f0
[ 3142.830958][ T2649]        kthread+0x125/0x140
[ 3142.832674][ T2649]        ret_from_fork+0x3a/0x50
[ 3142.834915][ T2649]
[ 3142.834915][ T2649] -> #0 ((wq_completion)bcache_writeback_wq){+.+.}:
[ 3142.838121][ T2649]        lock_acquire+0xb4/0x1c0
[ 3142.840025][ T2649]        flush_workqueue+0xae/0x4c0
[ 3142.842035][ T2649]        drain_workqueue+0xa9/0x180
[ 3142.844042][ T2649]        destroy_workqueue+0x17/0x250
[ 3142.846142][ T2649]        cached_dev_free+0x52/0x120 [bcache]
[ 3142.848530][ T2649]        process_one_work+0x2a4/0x640
[ 3142.850663][ T2649]        worker_thread+0x39/0x3f0
[ 3142.852464][ T2649]        kthread+0x125/0x140
[ 3142.854106][ T2649]        ret_from_fork+0x3a/0x50
[ 3142.855880][ T2649]
[ 3142.855880][ T2649] other info that might help us debug this:
[ 3142.855880][ T2649]
[ 3142.859663][ T2649] Chain exists of:
[ 3142.859663][ T2649]   (wq_completion)bcache_writeback_wq --> (work_completion)(&cl->work)#2 --> &bch_register_lock
[ 3142.859663][ T2649]
[ 3142.865424][ T2649]  Possible unsafe locking scenario:
[ 3142.865424][ T2649]
[ 3142.868022][ T2649]        CPU0                    CPU1
[ 3142.869885][ T2649]        ----                    ----
[ 3142.871751][ T2649]   lock(&bch_register_lock);
[ 3142.873379][ T2649]                                lock((work_completion)(&cl->work)#2);
[ 3142.876399][ T2649]                                lock(&bch_register_lock);
[ 3142.879727][ T2649]   lock((wq_completion)bcache_writeback_wq);
[ 3142.882064][ T2649]
[ 3142.882064][ T2649]  *** DEADLOCK ***
[ 3142.882064][ T2649]
[ 3142.885060][ T2649] 3 locks held by kworker/3:67/2649:
[ 3142.887245][ T2649]  #0: 00000000e774cdd0 ((wq_completion)events){+.+.}, at: process_one_work+0x21e/0x640
[ 3142.890815][ T2649]  #1: 00000000f7df89da ((work_completion)(&cl->work)#2){+.+.}, at: process_one_work+0x21e/0x640
[ 3142.894884][ T2649]  #2: 000000004fcf89c5 (&bch_register_lock){+.+.}, at: cached_dev_free+0x17/0x120 [bcache]
[ 3142.898797][ T2649]
[ 3142.898797][ T2649] stack backtrace:
[ 3142.900961][ T2649] CPU: 3 PID: 2649 Comm: kworker/3:67 Tainted: G        W         5.2.0-rc4-lp151.20-default+ #1
[ 3142.904789][ T2649] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[ 3142.909168][ T2649] Workqueue: events cached_dev_free [bcache]
[ 3142.911422][ T2649] Call Trace:
[ 3142.912656][ T2649]  dump_stack+0x85/0xcb
[ 3142.914181][ T2649]  print_circular_bug+0x19a/0x1f0
[ 3142.916193][ T2649]  __lock_acquire+0x16cd/0x1850
[ 3142.917936][ T2649]  ? __lock_acquire+0x6a8/0x1850
[ 3142.919704][ T2649]  ? lock_acquire+0xb4/0x1c0
[ 3142.921335][ T2649]  ? find_held_lock+0x34/0xa0
[ 3142.923052][ T2649]  lock_acquire+0xb4/0x1c0
[ 3142.924635][ T2649]  ? flush_workqueue+0x87/0x4c0
[ 3142.926375][ T2649]  flush_workqueue+0xae/0x4c0
[ 3142.928047][ T2649]  ? flush_workqueue+0x87/0x4c0
[ 3142.929824][ T2649]  ? drain_workqueue+0xa9/0x180
[ 3142.931686][ T2649]  drain_workqueue+0xa9/0x180
[ 3142.933534][ T2649]  destroy_workqueue+0x17/0x250
[ 3142.935787][ T2649]  cached_dev_free+0x52/0x120 [bcache]
[ 3142.937795][ T2649]  process_one_work+0x2a4/0x640
[ 3142.939803][ T2649]  worker_thread+0x39/0x3f0
[ 3142.941487][ T2649]  ? process_one_work+0x640/0x640
[ 3142.943389][ T2649]  kthread+0x125/0x140
[ 3142.944894][ T2649]  ? kthread_create_worker_on_cpu+0x70/0x70
[ 3142.947744][ T2649]  ret_from_fork+0x3a/0x50
[ 3142.970358][ T2649] bcache: bcache_device_free() bcache0 stopped

Here is how the deadlock happens.
1) bcache_reboot() calls bcache_device_stop(), then inside
   bcache_device_stop() BCACHE_DEV_CLOSING bit is set on d->flags.
   Then closure_queue(&d->cl) is called to invoke cached_dev_flush().
2) In cached_dev_flush(), cached_dev_free() is called by continu_at().
3) In cached_dev_free(), when stopping the writeback kthread of the
   cached device by kthread_stop(), dc->writeback_thread will be waken
   up to quite the kthread while-loop, then cached_dev_put() is called
   in bch_writeback_thread().
4) Calling cached_dev_put() in writeback kthread may drop dc->count to
   0, then dc->detach kworker is scheduled, which is initialized as
   cached_dev_detach_finish().
5) Inside cached_dev_detach_finish(), the last line of code is to call
   closure_put(&dc->disk.cl), which drops the last reference counter of
   closrure dc->disk.cl, then the callback cached_dev_flush() gets
   called.
Now cached_dev_flush() is called for second time in the code path, the
first time is in step 2). And again bch_register_lock will be acquired
again, and a A-A lock (lockdep terminology) is happening.

The root cause of the above A-A lock is in cached_dev_free(), mutex
bch_register_lock is held before stopping writeback kthread and other
kworkers. Fortunately now we have variable 'bcache_is_reboot', which may
prevent device registration or unregistration during reboot/shutdown
time, so it is unncessary to hold bch_register_lock such early now.

This is how this patch fixes the reboot/shutdown time A-A lock issue:
After moving mutex_lock(&bch_register_lock) to a later location where
before atomic_read(&dc->running) in cached_dev_free(), such A-A lock
problem can be solved without any reboot time registration race.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li 97ba3b816e bcache: acquire bch_register_lock later in cached_dev_detach_finish()
Now there is variable bcache_is_reboot to prevent device register or
unregister during reboot, it is unncessary to still hold mutex lock
bch_register_lock before stopping writeback_rate_update kworker and
writeback kthread. And if the stopping kworker or kthread holding
bch_register_lock inside their routine (we used to have such problem
in writeback thread, thanks to Junhui Wang fixed it), it is very easy
to introduce deadlock during reboot/shutdown procedure.

Therefore in this patch, the location to acquire bch_register_lock is
moved to the location before calling calc_cached_dev_sectors(). Which
is later then original location in cached_dev_detach_finish().

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li a59ff6ccc2 bcache: avoid a deadlock in bcache_reboot()
It is quite frequently to observe deadlock in bcache_reboot() happens
and hang the system reboot process. The reason is, in bcache_reboot()
when calling bch_cache_set_stop() and bcache_device_stop() the mutex
bch_register_lock is held. But in the process to stop cache set and
bcache device, bch_register_lock will be acquired again. If this mutex
is held here, deadlock will happen inside the stopping process. The
aftermath of the deadlock is, whole system reboot gets hung.

The fix is to avoid holding bch_register_lock for the following loops
in bcache_reboot(),
       list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
                bch_cache_set_stop(c);

        list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
                bcache_device_stop(&dc->disk);

A module range variable 'bcache_is_reboot' is added, it sets to true
in bcache_reboot(). In register_bcache(), if bcache_is_reboot is checked
to be true, reject the registration by returning -EBUSY immediately.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li 5c2a634cbf bcache: stop writeback kthread and kworker when bch_cached_dev_run() failed
In bch_cached_dev_attach() after bch_cached_dev_writeback_start()
called, the wrireback kthread and writeback rate update kworker of the
cached device are created, if the following bch_cached_dev_run()
failed, bch_cached_dev_attach() will return with -ENOMEM without
stopping the writeback related kthread and kworker.

This patch stops writeback kthread and writeback rate update kworker
before returning -ENOMEM if bch_cached_dev_run() returns error.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li f54d801dda bcache: destroy dc->writeback_write_wq if failed to create dc->writeback_thread
Commit 9baf30972b ("bcache: fix for gc and write-back race") added a
new work queue dc->writeback_write_wq, but forgot to destroy it in the
error condition when creating dc->writeback_thread failed.

This patch destroys dc->writeback_write_wq if kthread_create() returns
error pointer to dc->writeback_thread, then a memory leak is avoided.

Fixes: 9baf30972b ("bcache: fix for gc and write-back race")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li 5461999848 bcache: fix mistaken sysfs entry for io_error counter
In bch_cached_dev_files[] from driver/md/bcache/sysfs.c, sysfs_errors is
incorrectly inserted in. The correct entry should be sysfs_io_errors.

This patch fixes the problem and now I/O errors of cached device can be
read from /sys/block/bcache<N>/bcache/io_errors.

Fixes: c7b7bd0740 ("bcache: add io_disable to struct cached_dev")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00
Coly Li 0c277e211a bcache: add pendings_cleanup to stop pending bcache device
If a bcache device is in dirty state and its cache set is not
registered, this bcache device will not appear in /dev/bcache<N>,
and there is no way to stop it or remove the bcache kernel module.

This is an as-designed behavior, but sometimes people has to reboot
whole system to release or stop the pending backing device.

This sysfs interface may remove such pending bcache devices when
write anything into the sysfs file manually.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-28 07:39:16 -06:00