linux-stable.git/drivers/md, branch v4.9.256

dm: avoid filesystem lookup in dm_get_dev_t()

2021-01-30T12:27:14+00:00

commit 809b1e4945774c9ec5619a8f4e2189b7b3833c0c upstream.

This reverts commit
644bda6f3460 ("dm table: fall back to getting device using name_to_dev_t()")

dm_get_dev_t() is just used to convert an arbitrary 'path' string
into a dev_t. It doesn't presume that the device is present; that
check will be done later, as the only caller is dm_get_device(),
which does a dm_get_table_device() later on, which will properly
open the device.

So if the path string already _is_ in major:minor representation
we can convert it directly, avoiding a recursion into the filesystem
to lookup the block device.

This avoids a hang in multipath_message() when the filesystem is
inaccessible.

Fixes: 644bda6f3460 ("dm table: fall back to getting device using name_to_dev_t()")
Cc: stable@vger.kernel.org
Signed-off-by: Hannes Reinecke 
Signed-off-by: Martin Wilck 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm ioctl: fix error return code in target_message

2020-12-29T12:44:58+00:00

[ Upstream commit 4d7659bfbe277a43399a4a2d90fca141e70f29e1 ]

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 2ca4c92f58f9 ("dm ioctl: prevent empty message")
Reported-by: Hulk Robot 
Signed-off-by: Qinglang Miao 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

md: fix a warning caused by a race between concurrent md_ioctl()s

2020-12-29T12:44:52+00:00

commit c731b84b51bf7fe83448bea8f56a6d55006b0615 upstream.

Syzkaller reports a warning as belows.
WARNING: CPU: 0 PID: 9647 at drivers/md/md.c:7169
...
Call Trace:
...
RIP: 0010:md_ioctl+0x4017/0x5980 drivers/md/md.c:7169
RSP: 0018:ffff888096027950 EFLAGS: 00010293
RAX: ffff88809322c380 RBX: 0000000000000932 RCX: ffffffff84e266f2
RDX: 0000000000000000 RSI: ffffffff84e299f7 RDI: 0000000000000007
RBP: ffff888096027bc0 R08: ffff88809322c380 R09: ffffed101341a482
R10: ffff888096027940 R11: ffff88809a0d240f R12: 0000000000000932
R13: ffff8880a2c14100 R14: ffff88809a0d2268 R15: ffff88809a0d2408
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0xece/0x1c10 block/ioctl.c:606
 block_ioctl+0xee/0x130 fs/block_dev.c:1930
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

This is caused by a race between two concurrenct md_ioctl()s closing
the array.
CPU1 (md_ioctl())                   CPU2 (md_ioctl())
------                              ------
set_bit(MD_CLOSING, &mddev->flags);
did_set_md_closing = true;
                                    WARN_ON_ONCE(test_bit(MD_CLOSING,
                                            &mddev->flags));
if(did_set_md_closing)
    clear_bit(MD_CLOSING, &mddev->flags);

Fix the warning by returning immediately if the MD_CLOSING bit is set
in &mddev->flags which indicates that the array is being closed.

Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
Reported-by: syzbot+1e46a0864c1a6e9bd3d8@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dae R. Jeong 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

dm table: Remove BUG_ON(in_interrupt())

2020-12-29T12:44:51+00:00

[ Upstream commit e7b624183d921b49ef0a96329f21647d38865ee9 ]

The BUG_ON(in_interrupt()) in dm_table_event() is a historic leftover from
a rework of the dm table code which changed the calling context.

Issuing a BUG for a wrong calling context is frowned upon and
in_interrupt() is deprecated and only covering parts of the wrong
contexts. The sanity check for the context is covered by
CONFIG_DEBUG_ATOMIC_SLEEP and other debug facilities already.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

md/raid5: fix oops during stripe resizing

2020-11-10T09:23:55+00:00

commit b44c018cdf748b96b676ba09fdbc5b34fc443ada upstream.

KoWei reported crash during raid5 reshape:

[ 1032.252932] Oops: 0002 [#1] SMP PTI
[...]
[ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10
[...]
[ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286
[ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000
[ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000
[ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8
[ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8
[ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
[ 1032.252958] FS:  0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000
[ 1032.252959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0
[ 1032.252962] Call Trace:
[ 1032.252969]  ? async_memcpy+0x179/0x1000 [async_memcpy]
[ 1032.252977]  ? raid5_release_stripe+0x8e/0x110 [raid456]
[ 1032.252982]  handle_stripe_expansion+0x15a/0x1f0 [raid456]
[ 1032.252988]  handle_stripe+0x592/0x1270 [raid456]
[ 1032.252993]  handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456]
[ 1032.252999]  raid5d+0x35c/0x550 [raid456]
[ 1032.253002]  ? schedule+0x42/0xb0
[ 1032.253006]  ? schedule_timeout+0x10e/0x160
[ 1032.253011]  md_thread+0x97/0x160
[ 1032.253015]  ? wait_woken+0x80/0x80
[ 1032.253019]  kthread+0x104/0x140
[ 1032.253022]  ? md_start_sync+0x60/0x60
[ 1032.253024]  ? kthread_park+0x90/0x90
[ 1032.253027]  ret_from_fork+0x35/0x40

This is because cache_size_mutex was unlocked too early in resize_stripes,
which races with grow_one_stripe() that grow_one_stripe() allocates a
stripe with wrong pool_size.

Fix this issue by unlocking cache_size_mutex after updating pool_size.

Cc:  # v4.4+
Reported-by: KoWei Sung 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md/bitmap: md_bitmap_get_counter returns wrong blocks

2020-11-10T09:23:54+00:00

[ Upstream commit d837f7277f56e70d82b3a4a037d744854e62f387 ]

md_bitmap_get_counter() has code:

```
    if (bitmap->bp[page].hijacked ||
        bitmap->bp[page].map == NULL)
        csize = ((sector_t)1) << (bitmap->chunkshift +
                      PAGE_COUNTER_SHIFT - 1);
```

The minus 1 is wrong, this branch should report 2048 bits of space.
With "-1" action, this only report 1024 bit of space.

This bug code returns wrong blocks, but it doesn't inflence bitmap logic:
1. Most callers focus this function return value (the counter of offset),
   not the parameter blocks.
2. The bug is only triggered when hijacked is true or map is NULL.
   the hijacked true condition is very rare.
   the "map == null" only true when array is creating or resizing.
3. Even the caller gets wrong blocks, current code makes caller just to
   call md_bitmap_get_counter() one more time.

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

bcache: fix a lost wake-up problem caused by mca_cannibalize_lock

2020-10-01T18:40:03+00:00

[ Upstream commit 34cf78bf34d48dddddfeeadb44f9841d7864997a ]

This patch fix a lost wake-up problem caused by the race between
mca_cannibalize_lock and bch_cannibalize_unlock.

Consider two processes, A and B. Process A is executing
mca_cannibalize_lock, while process B takes c->btree_cache_alloc_lock
and is executing bch_cannibalize_unlock. The problem happens that after
process A executes cmpxchg and will execute prepare_to_wait. In this
timeslice process B executes wake_up, but after that process A executes
prepare_to_wait and set the state to TASK_INTERRUPTIBLE. Then process A
goes to sleep but no one will wake up it. This problem may cause bcache
device to dead.

Signed-off-by: Guoju Fang 
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

dm thin metadata: Avoid returning cmd->bm wild pointer on error

2020-09-12T09:47:37+00:00

commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream.

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

Signed-off-by: Ye Bin 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm cache metadata: Avoid returning cmd->bm wild pointer on error

2020-09-12T09:47:37+00:00

commit d16ff19e69ab57e08bf908faaacbceaf660249de upstream.

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

Signed-off-by: Ye Bin 
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

overflow.h: Add allocation size calculation helpers

2020-09-03T09:21:22+00:00

commit 610b15c50e86eb1e4b77274fabcaea29ac72d6a8 upstream.

In preparation for replacing unchecked overflows for memory allocations,
this creates helpers for the 3 most common calculations:

array_size(a, b): 2-dimensional array
array3_size(a, b, c): 3-dimensional array
struct_size(ptr, member, n): struct followed by n-many trailing members

Each of these return SIZE_MAX on overflow instead of wrapping around.

(Additionally renames a variable named "array_size" to avoid future
collision.)

Co-developed-by: Matthew Wilcox 
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman