[ Upstream commit 58b6e5e8f1addd44583d61b0a03c0f5519527e35 ]
When mknod is used to create a block special file in hugetlbfs, it will
allocate an inode and kmalloc a 'struct resv_map' via resv_map_alloc().
inode->i_mapping->private_data will point the newly allocated resv_map.
However, when the device special file is opened bd_acquire() will set
inode->i_mapping to bd_inode->i_mapping. Thus the pointer to the
allocated resv_map is lost and the structure is leaked.
Programs to reproduce:
mount -t hugetlbfs nodev hugetlbfs
mknod hugetlbfs/dev b 0 0
exec 30<> hugetlbfs/dev
umount hugetlbfs/
resv_map structures are only needed for inodes which can have associated
page allocations. To fix the leak, only allocate resv_map for those
inodes which could possibly be associated with page allocations.
Link: http://lkml.kernel.org/r/20190401213101.16476-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Yufen Yu <yuyufen@huawei.com>
Suggested-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 93b919da64c15b90953f96a536e5e61df896ca57 ]
symlink body shouldn't be freed without an RCU delay. Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback. Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4fdcfab5b5537c21891e22e65996d4d0dd8ab4ca ]
free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit daf5cc27eed99afdea8d96e71b89ba41f5406ef6 ]
free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
[ Upstream commit 5a698243930c441afccec04e4d5dc8febfd2b775 ]
Specifying a retrans=0 mount parameter to a NFS/TCP mount, is
inadvertently causing the NFS client to rewrite any specified
timeout parameter to the default of 60 seconds.
Fixes: a956beda19a6 ("NFS: Allow the mount option retrans=0")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
commit 15fab63e1e57be9fdb5eec1bbc5916e9825e9acb upstream.
Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount. All
callers converted to handle a failure.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7c2bd9a39845bfb6d72ddb55ce737650271f6f96 upstream.
syzbot is reporting uninitialized value at rpc_sockaddr2uaddr() [1]. This
is because syzbot is setting AF_INET6 to "struct sockaddr_in"->sin_family
(which is embedded into user-visible "struct nfs_mount_data" structure)
despite nfs23_validate_mount_data() cannot pass sizeof(struct sockaddr_in6)
bytes of AF_INET6 address to rpc_sockaddr2uaddr().
Since "struct nfs_mount_data" structure is user-visible, we can't change
"struct nfs_mount_data" to use "struct sockaddr_storage". Therefore,
assuming that everybody is using AF_INET family when passing address via
"struct nfs_mount_data"->addr, reject if its sin_family is not AF_INET.
[1] https://syzkaller.appspot.com/bug?id=599993614e7cbbf66bc2656a919ab2a95fb5d75c
Reported-by: syzbot <syzbot+047a11c361b872896a4f@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6abc8caa6deb14be2a206253f7e1c5e37e9515b upstream.
If there are multiple callbacks queued, waiting for the callback
slot when the callback gets shut down, then they all currently
end up acting as if they hold the slot, and call
nfsd4_cb_sequence_done() resulting in interesting side-effects.
In addition, the 'retry_nowait' path in nfsd4_cb_sequence_done()
causes a loop back to nfsd4_cb_prepare() without first freeing the
slot, which causes a deadlock when nfsd41_cb_get_slot() gets called
a second time.
This patch therefore adds a boolean to track whether or not the
callback did pick up the slot, so that it can do the right thing
in these 2 cases.
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 37659182bff1eeaaeadcfc8f853c6d2b6dbc3f47 upstream.
We missed two places that i_wrbuffer_ref_head, i_wr_ref, i_dirty_caps
and i_flushing_caps may change. When they are all zeros, we should free
i_head_snapc.
Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/38224
Reported-and-tested-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1bcb344086f3ecf8d6705f6d708441baa823beb3 upstream.
Ben reported tripping the BUG_ON in create_request_message during some
performance testing. Analysis of the vmcore showed that the length of
the r_dentry->d_name string changed after we allocated the buffer, but
before we encoded it.
build_dentry_path returns pointers to d_name in the common case of
non-snapped dentries, but this optimization isn't safe unless the parent
directory is locked. When it isn't, have the code make a copy of the
d_name while holding the d_lock.
Cc: stable@vger.kernel.org
Reported-by: Ben England <bengland@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b987222654f84f7b4ca95b3a55eca784cb30235b upstream.
This fixes multiple issues in buffer_pipe_buf_ops:
- The ->steal() handler must not return zero unless the pipe buffer has
the only reference to the page. But generic_pipe_buf_steal() assumes
that every reference to the pipe is tracked by the page's refcount,
which isn't true for these buffers - buffer_pipe_buf_get(), which
duplicates a buffer, doesn't touch the page's refcount.
Fix it by using generic_pipe_buf_nosteal(), which refuses every
attempted theft. It should be easy to actually support ->steal, but the
only current users of pipe_buf_steal() are the virtio console and FUSE,
and they also only use it as an optimization. So it's probably not worth
the effort.
- The ->get() and ->release() handlers can be invoked concurrently on pipe
buffers backed by the same struct buffer_ref. Make them safe against
concurrency by using refcount_t.
- The pointers stored in ->private were only zeroed out when the last
reference to the buffer_ref was dropped. As far as I know, this
shouldn't be necessary anyway, but if we do it, let's always do it.
Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Fixes: 73a757e63114d ("ring-buffer: Return reader page back into existing ring buffer")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 652727bbe1b17993636346716ae5867627793647 upstream.
A path-based rename returning EBUSY will incorrectly try opening
the file with a cifs (NT Create AndX) operation on an smb2+ mount,
which causes the server to force a session close.
If the mount is smb2+, skip the fallback.
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e643cd094de3bd0f97edcc1db0089afa24d909f upstream.
The new attribute leaf buffer is not held locked across the transaction
roll between the shortform->leaf modification and the addition of the
new entry. As a result, the attribute buffer modification being made is
not atomic from an operational perspective. Hence the AIL push can grab
it in the transient state of "just created" after the initial
transaction is rolled, because the buffer has been released. This leads
to xfs_attr3_leaf_verify() asserting that hdr.count is zero, treating
this as in-memory corruption, and shutting down the filesystem.
Darrick ported the original patch to 4.15 and reworked it use the
xfs_defer_bjoin helper and hold/join the buffer correctly across the
second transaction roll.
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Lyakas <alex@zadara.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b7b2846fe26f2c0d7f317c874a13d3ecf22670ff upstream.
In certain cases, defer_ops callers will lock a buffer and want to hold
the lock across transaction rolls. Similar to ijoined inodes, we want
to dirty & join the buffer with each transaction roll in defer_finish so
that afterwards the caller still owns the buffer lock and we haven't
inadvertently pinned the log.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Lyakas <alex@zadara.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a9d929d6e13278df62bd9e3d3ceae8c87ad1eea upstream.
If two programs simultaneously try to write to the same part of a file
via direct IO and buffered IO, there's a chance that the post-diowrite
pagecache invalidation will fail on the dirty page. When this happens,
the dio write succeeded, which means that the page cache is no longer
coherent with the disk!
Programs are not supposed to mix IO types and this is a clear case of
data corruption, so store an EIO which will be reflected to userspace
during the next fsync. Replace the WARN_ON with a ratelimited pr_crit
so that the developers have /some/ kind of breadcrumb to track down the
offending program(s) and file(s) involved.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Zubin Mithra <zsm@chromium.org>
commit 04f5866e41fb70690e28397487d8bd8eea7d712a upstream.
The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it. Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier. For example in Hugh's post from Jul 2017:
https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils
"Not strictly relevant here, but a related note: I was very surprised
to discover, only quite recently, how handle_mm_fault() may be called
without down_read(mmap_sem) - when core dumping. That seems a
misguided optimization to me, which would also be nice to correct"
In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.
Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.
Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.
For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs. Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.
Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.
In order to facilitate the backporting I added "Fixes: 86039bd3b4e6"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.
Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm(). The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.
Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b98749cac4a695f084a5ff076f4510b23e353ecd upstream.
In the oplock break handler, writing pending changes from pages puts
the FileInfo handle. If the refcount reaches zero it closes the handle
and waits for any oplock break handler to return, thus causing a deadlock.
To prevent this situation:
* We add a wait flag to cifsFileInfo_put() to decide whether we should
wait for running/pending oplock break handlers
* We keep an additionnal reference of the SMB FileInfo handle so that
for the rest of the handler putting the handle won't close it.
- The ref is bumped everytime we queue the handler via the
cifs_queue_oplock_break() helper.
- The ref is decremented at the end of the handler
This bug was triggered by xfstest 464.
Also important fix to address the various reports of
oops in smb2_push_mandatory_locks
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3b7960caceafdfc2cdfe2850487f8d091eb41144 ]
In cases where queryinfo fails, we have cases in cifs (vers=1.0)
where with backupuid mounts we retry the query info with findfirst.
This doesn't work to some NetApp servers which don't support
WindowsXP (and later) infolevel 261 (SMB_FIND_FILE_ID_FULL_DIR_INFO)
so in this case use other info levels (in this case it will usually
be level 257, SMB_FIND_FILE_DIRECTORY_INFO).
(Also fixes some indentation)
See kernel bugzilla 201435
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5e172f75e51e3de1b4274146d9b990f803cb5c2a ]
The default P9_LOCK_TIMEOUT can be too long for some users exporting
a local file system to a guest VM (30s), make this configurable at
mount time.
Link: http://lkml.kernel.org/r/1536295827-3181-1-git-send-email-asmadeus@codewreck.org
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195727
Signed-off-by: Dinu-Razvan Chis-Serban <justcsdr@gmail.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 18915b5873f07e5030e6fb108a050fa7c71c59fb ]
The ext4 fstrim implementation uses the block bitmaps to find free space
that can be discarded. If we haven't replayed the journal, the bitmaps
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 85f9987b236cf46e06ffdb5c225cf1f3c0acb789 ]
It was mapped to EIO which can be confusing when user space
queries for an object GUID for an object for which the server
file system doesn't support (or hasn't saved one).
As Amir Goldstein suggested this is similar to ENOATTR
(equivalently ENODATA in Linux errno definitions) so
changing NT STATUS code mapping for OBJECTID_NOT_FOUND
to ENODATA.
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6c7328400e0488f7d49e19e02290ba343b6811b2 ]
Currently when the file system resize using ext4_resize_fs() fails it
will report into log that "resized filesystem to <requested block
count>". However this may not be true in the case of failure. Use the
current block count as returned by ext4_blocks_count() to report the
block count.
Additionally, report a warning that "error occurred during file system
resize"
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d64264d6218e6892edd832dc3a5a5857c2856c53 ]
Currently in add_new_gdb_meta_bg() there is a missing brelse of gdb_bh
in case ext4_journal_get_write_access() fails.
Additionally kvfree() is missing in the same error path. Fix it by
moving the ext4_journal_get_write_access() before the ext4 sb update as
Ted suggested and release n_group_desc and gdb_bh in case it fails.
Fixes: 61a9c11e5e7a ("ext4: add missing brelse() add_new_gdb_meta_bg()'s error path")
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a89afe58f1a74aac768a5eb77af95ef4ee15beaa upstream.
If the last bio returned is not dio->bio, the status of the bio will
not assigned to dio->bio if it is error. This will cause the whole IO
status wrong.
ksoftirqd/21-117 [021] ..s. 4017.966090: 8,0 C N 4883648 [0]
<idle>-0 [018] ..s. 4017.970888: 8,0 C WS 4924800 + 1024 [0]
<idle>-0 [018] ..s. 4017.970909: 8,0 D WS 4935424 + 1024 [<idle>]
<idle>-0 [018] ..s. 4017.970924: 8,0 D WS 4936448 + 321 [<idle>]
ksoftirqd/21-117 [021] ..s. 4017.995033: 8,0 C R 4883648 + 336 [65475]
ksoftirqd/21-117 [021] d.s. 4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7
ksoftirqd/21-117 [021] d.s. 4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0
We always have to assign bio->bi_status to dio->bio.bi_status because we
will only check dio->bio.bi_status when we return the whole IO to
the upper layer.
Fixes: 542ff7bf18c6 ("block: new direct I/O implementation")
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 272e5326c7837697882ce3162029ba893059b616 upstream.
The compression property resets to NULL, instead of the old value if we
fail to set the new compression parameter.
$ btrfs prop get /btrfs compression
compression=lzo
$ btrfs prop set /btrfs compression zli
ERROR: failed to set compression for /btrfs: Invalid argument
$ btrfs prop get /btrfs compression
This is because the compression property ->validate() is successful for
'zli' as the strncmp() used the length passed from the userspace.
Fix it by using the expected string length in strncmp().
Fixes: 63541927c8d1 ("Btrfs: add support for inode properties")
Fixes: 5c1aab1dd544 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 50398fde997f6be8faebdb5f38e9c9c467370f51 upstream.
We let pass zstd compression parameter even if it is not fully valid.
For example:
$ btrfs prop set /btrfs compression zst
$ btrfs prop get /btrfs compression
compression=zst
zlib and lzo are fine.
Fix it by checking the correct prefix length.
Fixes: 5c1aab1dd544 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f35f06c35560a86e841631f0243b83a984dc11a9 upstream.
Whan a filesystem is mounted with the nologreplay mount option, which
requires it to be mounted in RO mode as well, we can not allow discard on
free space inside block groups, because log trees refer to extents that
are not pinned in a block group's free space cache (pinning the extents is
precisely the first phase of replaying a log tree).
So do not allow the fitrim ioctl to do anything when the filesystem is
mounted with the nologreplay option, because later it can be mounted RW
without that option, which causes log replay to happen and result in
either a failure to replay the log trees (leading to a mount failure), a
crash or some silent corruption.
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Fixes: 96da09192cda ("btrfs: Introduce new mount option to disable tree log replay")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 538bcaa6261b77e71d37f5596c33127c1a3ec3f7 ]
The jbd2 superblock is lockless now, so there is probably a race
condition between writing it so disk and modifing contents of it, which
may lead to checksum error. The following race is the one case that we
have captured.
jbd2 fsstress
jbd2_journal_commit_transaction
jbd2_journal_update_sb_log_tail
jbd2_write_superblock
jbd2_superblock_csum_set jbd2_journal_revoke
jbd2_journal_set_features(revork)
modify superblock
submit_bh(checksum incorrect)
Fix this by locking the buffer head before modifing it. We always
write the jbd2 superblock after we modify it, so this just means
calling the lock_buffer() a little earlier.
This checksum corruption problem can be reproduced by xfstests
generic/475.
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc4b1242d7e3b42eed73881fc749944146493e4f ]
The preadv2 and pwritev2 syscalls are supposed to emulate the readv and
writev syscalls when offset == -1. Therefore the compat code should
check for offset before calling do_compat_preadv64 and
do_compat_pwritev64. This is the case for the preadv2 and pwritev2
syscalls, but handling of offset == -1 is missing in their 64-bit
equivalent.
This patch fixes that, calling do_compat_readv and do_compat_writev when
offset == -1. This fixes the following glibc tests on x32:
- misc/tst-preadvwritev2
- misc/tst-preadvwritev64v2
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dce30ca9e3b676fb288c33c1f4725a0621361185 ]
guard_bio_eod() can truncate a segment in bio to allow it to do IO on
odd last sectors of a device.
It already checks if the IO starts past EOD, but it does not consider
the possibility of an IO request starting within device boundaries can
contain more than one segment past EOD.
In such cases, truncated_bytes can be bigger than PAGE_SIZE, and will
underflow bvec->bv_len.
Fix this by checking if truncated_bytes is lower than PAGE_SIZE.
This situation has been found on filesystems such as isofs and vfat,
which doesn't check the device size before mount, if the device is
smaller than the filesystem itself, a readahead on such filesystem,
which spans EOD, can trigger this situation, leading a call to
zero_user() with a wrong size possibly corrupting memory.
I didn't see any crash, or didn't let the system run long enough to
check if memory corruption will be hit somewhere, but adding
instrumentation to guard_bio_end() to check truncated_bytes size, was
enough to see the error.
The following script can trigger the error.
MNT=/mnt
IMG=./DISK.img
DEV=/dev/loop0
mkfs.vfat $IMG
mount $IMG $MNT
cp -R /etc $MNT &> /dev/null
umount $MNT
losetup -D
losetup --find --show --sizelimit 16247280 $IMG
mount $DEV $MNT
find $MNT -type f -exec cat {} + >/dev/null
Kudos to Eric Sandeen for coming up with the reproducer above
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6e876c3dd205d30b0db6850e97a03d75457df007 ]
In jbd2_journal_commit_transaction(), if we are in abort mode,
we may flush the buffer without setting descriptor block checksum
by goto start_journal_io. Then fs is mounted,
jbd2_descriptor_block_csum_verify() failed.
[ 271.379811] EXT4-fs (vdd): shut down requested (2)
[ 271.381827] Aborting journal on device vdd-8.
[ 271.597136] JBD2: Invalid checksum recovering block 22199 in log
[ 271.598023] JBD2: recovery failed
[ 271.598484] EXT4-fs (vdd): error loading journal
Fix this problem by keep setting descriptor block checksum if the
descriptor buffer is not NULL.
This checksum problem can be reproduced by xfstests generic/388.
Signed-off-by: luojiajun <luojiajun3@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 68e2672f8fbd1e04982b8d2798dd318bf2515dd2 ]
There is a NULL pointer dereference of devname in strspn()
The oops looks something like:
CIFS: Attempting to mount (null)
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
...
RIP: 0010:strspn+0x0/0x50
...
Call Trace:
? cifs_parse_mount_options+0x222/0x1710 [cifs]
? cifs_get_volume_info+0x2f/0x80 [cifs]
cifs_setup_volume_info+0x20/0x190 [cifs]
cifs_get_volume_info+0x50/0x80 [cifs]
cifs_smb3_do_mount+0x59/0x630 [cifs]
? ida_alloc_range+0x34b/0x3d0
cifs_do_mount+0x11/0x20 [cifs]
mount_fs+0x52/0x170
vfs_kern_mount+0x6b/0x170
do_mount+0x216/0xdc0
ksys_mount+0x83/0xd0
__x64_sys_mount+0x25/0x30
do_syscall_64+0x65/0x220
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fix this by adding a NULL check on devname in cifs_parse_devname()
Signed-off-by: Yao Liu <yotta.liu@ucloud.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 259594bea574e515a148171b5cd84ce5cbdc028a ]
When compiling with -Wformat, clang emits the following warnings:
fs/cifs/smb1ops.c:312:20: warning: format specifies type 'unsigned
short' but the argument has type 'unsigned int' [-Wformat]
tgt_total_cnt, total_in_tgt);
^~~~~~~~~~~~
fs/cifs/cifs_dfs_ref.c:289:4: warning: format specifies type 'short'
but the argument has type 'int' [-Wformat]
ref->flags, ref->server_type);
^~~~~~~~~~
fs/cifs/cifs_dfs_ref.c:289:16: warning: format specifies type 'short'
but the argument has type 'int' [-Wformat]
ref->flags, ref->server_type);
^~~~~~~~~~~~~~~~
fs/cifs/cifs_dfs_ref.c:291:4: warning: format specifies type 'short'
but the argument has type 'int' [-Wformat]
ref->ref_flag, ref->path_consumed);
^~~~~~~~~~~~~
fs/cifs/cifs_dfs_ref.c:291:19: warning: format specifies type 'short'
but the argument has type 'int' [-Wformat]
ref->ref_flag, ref->path_consumed);
^~~~~~~~~~~~~~~~~~
The types of these arguments are unconditionally defined, so this patch
updates the format character to the correct ones for ints and unsigned
ints.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Louis Taylor <louis@kragniz.eu>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9083977dabf3833298ddcd40dee28687f1e6b483 ]
Fix below warning coming because of using mutex lock in atomic context.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:98
in_atomic(): 1, irqs_disabled(): 0, pid: 585, name: sh
Preemption disabled at: __radix_tree_preload+0x28/0x130
Call trace:
dump_backtrace+0x0/0x2b4
show_stack+0x20/0x28
dump_stack+0xa8/0xe0
___might_sleep+0x144/0x194
__might_sleep+0x58/0x8c
mutex_lock+0x2c/0x48
f2fs_trace_pid+0x88/0x14c
f2fs_set_node_page_dirty+0xd0/0x184
Do not use f2fs_radix_tree_insert() to avoid doing cond_resched() with
spin_lock() acquired.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc725ef3cb202ef2019a3c67c8913efa05c3cce6 ]
In the process of creating a node, it will cause NULL pointer
dereference in kernel if o2cb_ctl failed in the interval (mkdir,
o2cb_set_node_attribute(node_num)] in function o2cb_add_node.
The node num is initialized to 0 in function o2nm_node_group_make_item,
o2nm_node_group_drop_item will mistake the node number 0 for a valid
node number when we delete the node before the node number is set
correctly. If the local node number of the current host happens to be
0, cluster->cl_local_node will be set to O2NM_INVALID_NODE_NUM while
o2hb_thread still running. The panic stack is generated as follows:
o2hb_thread
\-o2hb_do_disk_heartbeat
\-o2hb_check_own_slot
|-slot = ®->hr_slots[o2nm_this_node()];
//o2nm_this_node() return O2NM_INVALID_NODE_NUM
We need to check whether the node number is set when we delete the node.
Link: http://lkml.kernel.org/r/133d8045-72cc-863e-8eae-5013f9f6bc51@huawei.com
Signed-off-by: Jia Guo <guojia12@huawei.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc31d0cdcfbadb6258b45db97e93b1c83822ba33 ]
We have a customer reporting crashes in lock_get_status() with many
"Leaked POSIX lock" messages preceeding the crash.
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x56 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
Leaked POSIX lock on dev=0x0:0x53 ...
POSIX: fl_owner=ffff8900e7b79380 fl_flags=0x1 fl_type=0x1 fl_pid=20709
Leaked POSIX lock on dev=0x0:0x4b ino...
Leaked locks on dev=0x0:0x4b ino=0xf911400000029:
POSIX: fl_owner=ffff89f41c870e00 fl_flags=0x1 fl_type=0x1 fl_pid=19592
stack segment: 0000 [#1] SMP
Modules linked in: binfmt_misc msr tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag rpcsec_gss_krb5 arc4 ecb auth_rpcgss nfsv4 md4 nfs nls_utf8 lockd grace cifs sunrpc ccm dns_resolver fscache af_packet iscsi_ibft iscsi_boot_sysfs vmw_vsock_vmci_transport vsock xfs libcrc32c sb_edac edac_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel drbg ansi_cprng vmw_balloon aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd joydev pcspkr vmxnet3 i2c_piix4 vmw_vmci shpchp fjes processor button ac btrfs xor raid6_pq sr_mod cdrom ata_generic sd_mod ata_piix vmwgfx crc32c_intel drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm serio_raw ahci libahci drm libata vmw_pvscsi sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
Supported: Yes
CPU: 6 PID: 28250 Comm: lsof Not tainted 4.4.156-94.64-default #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
task: ffff88a345f28740 ti: ffff88c74005c000 task.ti: ffff88c74005c000
RIP: 0010:[<ffffffff8125dcab>] [<ffffffff8125dcab>] lock_get_status+0x9b/0x3b0
RSP: 0018:ffff88c74005fd90 EFLAGS: 00010202
RAX: ffff89bde83e20ae RBX: ffff89e870003d18 RCX: 0000000049534f50
RDX: ffffffff81a3541f RSI: ffffffff81a3544e RDI: ffff89bde83e20ae
RBP: 0026252423222120 R08: 0000000020584953 R09: 000000000000ffff
R10: 0000000000000000 R11: ffff88c74005fc70 R12: ffff89e5ca7b1340
R13: 00000000000050e5 R14: ffff89e870003d30 R15: ffff89e5ca7b1340
FS: 00007fafd64be800(0000) GS:ffff89f41fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001c80018 CR3: 000000a522048000 CR4: 0000000000360670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
0000000000000208 ffffffff81a3d6b6 ffff89e870003d30 ffff89e870003d18
ffff89e5ca7b1340 ffff89f41738d7c0 ffff89e870003d30 ffff89e5ca7b1340
ffffffff8125e08f 0000000000000000 ffff89bc22b67d00 ffff88c74005ff28
Call Trace:
[<ffffffff8125e08f>] locks_show+0x2f/0x70
[<ffffffff81230ad1>] seq_read+0x251/0x3a0
[<ffffffff81275bbc>] proc_reg_read+0x3c/0x70
[<ffffffff8120e456>] __vfs_read+0x26/0x140
[<ffffffff8120e9da>] vfs_read+0x7a/0x120
[<ffffffff8120faf2>] SyS_read+0x42/0xa0
[<ffffffff8161cbc3>] entry_SYSCALL_64_fastpath+0x1e/0xb7
When Linux closes a FD (close(), close-on-exec, dup2(), ...) it calls
filp_close() which also removes all posix locks.
The lock struct is initialized like so in filp_close() and passed
down to cifs
...
lock.fl_type = F_UNLCK;
lock.fl_flags = FL_POSIX | FL_CLOSE;
lock.fl_start = 0;
lock.fl_end = OFFSET_MAX;
...
Note the FL_CLOSE flag, which hints the VFS code that this unlocking
is done for closing the fd.
filp_close()
locks_remove_posix(filp, id);
vfs_lock_file(filp, F_SETLK, &lock, NULL);
return filp->f_op->lock(filp, cmd, fl) => cifs_lock()
rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock, xid);
rc = server->ops->mand_unlock_range(cfile, flock, xid);
if (flock->fl_flags & FL_POSIX && !rc)
rc = locks_lock_file_wait(file, flock)
Notice how we don't call locks_lock_file_wait() which does the
generic VFS lock/unlock/wait work on the inode if rc != 0.
If we are closing the handle, the SMB server is supposed to remove any
locks associated with it. Similarly, cifs.ko frees and wakes up any
lock and lock waiter when closing the file:
cifs_close()
cifsFileInfo_put(file->private_data)
/*
* Delete any outstanding lock records. We'll lose them when the file
* is closed anyway.
*/
down_write(&cifsi->lock_sem);
list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
}
list_del(&cifs_file->llist->llist);
kfree(cifs_file->llist);
up_write(&cifsi->lock_sem);
So we can safely ignore unlocking failures in cifs_lock() if they
happen with the FL_CLOSE flag hint set as both the server and the
client take care of it during the actual closing.
This is not a proper fix for the unlocking failure but it's safe and
it seems to prevent the lock leakages and crashes the customer
experiences.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5e86bdda41534e17621d5a071b294943cae4376e upstream.
Currently, we are releasing the indirect buffer where we are done with
it in ext4_ind_remove_space(), so we can see the brelse() and
BUFFER_TRACE() everywhere. It seems fragile and hard to read, and we
may probably forget to release the buffer some day. This patch cleans
up the code by putting of the code which releases the buffers to the
end of the function.
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jari Ruusu <jari.ruusu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6a9467ea14bae8691b0f72c500510c42ea8edb8 upstream.
ocfs2_reflink_inodes_lock() can swap the inode1/inode2 variables so that
we always grab cluster locks in order of increasing inode number.
Unfortunately, we forget to swap the inode record buffer head pointers
when we've done this, which leads to incorrect bookkeepping when we're
trying to make the two inodes have the same refcount tree.
This has the effect of causing filesystem shutdowns if you're trying to
reflink data from inode 100 into inode 97, where inode 100 already has a
refcount tree attached and inode 97 doesn't. The reflink code decides
to copy the refcount tree pointer from 100 to 97, but uses inode 97's
inode record to open the tree root (which it doesn't have) and blows up.
This issue causes filesystem shutdowns and metadata corruption!
Link: http://lkml.kernel.org/r/20190312214910.GK20533@magnolia
Fixes: 29ac8e856cb369 ("ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73601ea5b7b18eb234219ae2adf77530f389da79 upstream.
syzbot is hitting lockdep warning [1] due to trying to open a fifo
during an execve() operation. But we don't need to open non regular
files during an execve() operation, for all files which we will need are
the executable file itself and the interpreter programs like /bin/sh and
ld-linux.so.2 .
Since the manpage for execve(2) says that execve() returns EACCES when
the file or a script interpreter is not a regular file, and the manpage
for uselib(2) says that uselib() can return EACCES, and we use
FMODE_EXEC when opening for execve()/uselib(), we can bail out if a non
regular file is requested with FMODE_EXEC set.
Since this deadlock followed by khungtaskd warnings is trivially
reproducible by a local unprivileged user, and syzbot's frequent crash
due to this deadlock defers finding other bugs, let's workaround this
deadlock until we get a chance to find a better solution.
[1] https://syzkaller.appspot.com/bug?id=b5095bfec44ec84213bac54742a82483aad578ce
Link: http://lkml.kernel.org/r/1552044017-7890-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Reported-by: syzbot <syzbot+e93a80c1bb7c5c56e522461c149f8bf55eab1b2b@syzkaller.appspotmail.com>
Fixes: 8924feff66f35fe2 ("splice: lift pipe_lock out of splice_to_pipe()")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org> [4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0cb98abb5bd13b9a636bde603d952d722688b428 upstream.
Allow the async rpc task for finish and update the open state if needed,
then free the slot. Otherwise, the async rpc unable to decode the reply.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: ae55e59da0e4 ("pnfs: Don't release the sequence slot...")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3897b6f0a859288c22fb793fad11ec2327e60fcd upstream.
Parity page is incorrectly unmapped in finish_parity_scrub(), triggering
a reference counter bug on i386, i.e.:
[ 157.662401] kernel BUG at mm/highmem.c:349!
[ 157.666725] invalid opcode: 0000 [#1] SMP PTI
The reason is that kunmap(p_page) was completely left out, so we never
did an unmap for the p_page and the loop unmapping the rbio page was
iterating over the wrong number of stripes: unmapping should be done
with nr_data instead of rbio->real_stripes.
Test case to reproduce the bug:
- create a raid5 btrfs filesystem:
# mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde
- mount it:
# mount /dev/sdb /mnt
- run btrfs scrub in a loop:
# while :; do btrfs scrub start -BR /mnt; done
BugLink: https://bugs.launchpad.net/bugs/1812845
Fixes: 5a6ac9eacb49 ("Btrfs, raid56: support parity scrub on raid56")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2cc8334270e281815c3850c3adea363c51f21e0d upstream.
When Filipe added the recursive directory logging stuff in
2f2ff0ee5e430 ("Btrfs: fix metadata inconsistencies after directory
fsync") he specifically didn't take the directory i_mutex for the
children directories that we need to log because of lockdep. This is
generally fine, but can lead to this WARN_ON() tripping if we happen to
run delayed deletion's in between our first search and our second search
of dir_item/dir_indexes for this directory. We expect this to happen,
so the WARN_ON() isn't necessary. Drop the WARN_ON() and add a comment
so we know why this case can happen.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
