commit 1e047eaab3bb5564f25b41e9cd3a053009f4e789 upstream.
syzbot is reporting deadlocks at __blkdev_get() [1].
----------------------------------------
[ 92.493919] systemd-udevd D12696 525 1 0x00000000
[ 92.495891] Call Trace:
[ 92.501560] schedule+0x23/0x80
[ 92.502923] schedule_preempt_disabled+0x5/0x10
[ 92.504645] __mutex_lock+0x416/0x9e0
[ 92.510760] __blkdev_get+0x73/0x4f0
[ 92.512220] blkdev_get+0x12e/0x390
[ 92.518151] do_dentry_open+0x1c3/0x2f0
[ 92.519815] path_openat+0x5d9/0xdc0
[ 92.521437] do_filp_open+0x7d/0xf0
[ 92.527365] do_sys_open+0x1b8/0x250
[ 92.528831] do_syscall_64+0x6e/0x270
[ 92.530341] entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 92.931922] 1 lock held by systemd-udevd/525:
[ 92.933642] #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x73/0x4f0
----------------------------------------
The reason of deadlock turned out that wait_event_interruptible() in
blk_queue_enter() got stuck with bdev->bd_mutex held at __blkdev_put()
due to q->mq_freeze_depth == 1.
----------------------------------------
[ 92.787172] a.out S12584 634 633 0x80000002
[ 92.789120] Call Trace:
[ 92.796693] schedule+0x23/0x80
[ 92.797994] blk_queue_enter+0x3cb/0x540
[ 92.803272] generic_make_request+0xf0/0x3d0
[ 92.807970] submit_bio+0x67/0x130
[ 92.810928] submit_bh_wbc+0x15e/0x190
[ 92.812461] __block_write_full_page+0x218/0x460
[ 92.815792] __writepage+0x11/0x50
[ 92.817209] write_cache_pages+0x1ae/0x3d0
[ 92.825585] generic_writepages+0x5a/0x90
[ 92.831865] do_writepages+0x43/0xd0
[ 92.836972] __filemap_fdatawrite_range+0xc1/0x100
[ 92.838788] filemap_write_and_wait+0x24/0x70
[ 92.840491] __blkdev_put+0x69/0x1e0
[ 92.841949] blkdev_close+0x16/0x20
[ 92.843418] __fput+0xda/0x1f0
[ 92.844740] task_work_run+0x87/0xb0
[ 92.846215] do_exit+0x2f5/0xba0
[ 92.850528] do_group_exit+0x34/0xb0
[ 92.852018] SyS_exit_group+0xb/0x10
[ 92.853449] do_syscall_64+0x6e/0x270
[ 92.854944] entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 92.943530] 1 lock held by a.out/634:
[ 92.945105] #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0x3c/0x1e0
----------------------------------------
The reason of q->mq_freeze_depth == 1 turned out that loop_set_status()
forgot to call blk_mq_unfreeze_queue() at error paths for
info->lo_encrypt_type != NULL case.
----------------------------------------
[ 37.509497] CPU: 2 PID: 634 Comm: a.out Tainted: G W 4.16.0+ #457
[ 37.513608] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
[ 37.518832] RIP: 0010:blk_freeze_queue_start+0x17/0x40
[ 37.521778] RSP: 0018:ffffb0c2013e7c60 EFLAGS: 00010246
[ 37.524078] RAX: 0000000000000000 RBX: ffff8b07b1519798 RCX: 0000000000000000
[ 37.527015] RDX: 0000000000000002 RSI: ffffb0c2013e7cc0 RDI: ffff8b07b1519798
[ 37.529934] RBP: ffffb0c2013e7cc0 R08: 0000000000000008 R09: 47a189966239b898
[ 37.532684] R10: dad78b99b278552f R11: 9332dca72259d5ef R12: ffff8b07acd73678
[ 37.535452] R13: 0000000000004c04 R14: 0000000000000000 R15: ffff8b07b841e940
[ 37.538186] FS: 00007fede33b9740(0000) GS:ffff8b07b8e80000(0000) knlGS:0000000000000000
[ 37.541168] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 37.543590] CR2: 00000000206fdf18 CR3: 0000000130b30006 CR4: 00000000000606e0
[ 37.546410] Call Trace:
[ 37.547902] blk_freeze_queue+0x9/0x30
[ 37.549968] loop_set_status+0x67/0x3c0 [loop]
[ 37.549975] loop_set_status64+0x3b/0x70 [loop]
[ 37.549986] lo_ioctl+0x223/0x810 [loop]
[ 37.549995] blkdev_ioctl+0x572/0x980
[ 37.550003] block_ioctl+0x34/0x40
[ 37.550006] do_vfs_ioctl+0xa7/0x6d0
[ 37.550017] ksys_ioctl+0x6b/0x80
[ 37.573076] SyS_ioctl+0x5/0x10
[ 37.574831] do_syscall_64+0x6e/0x270
[ 37.576769] entry_SYSCALL_64_after_hwframe+0x42/0xb7
----------------------------------------
[1] https://syzkaller.appspot.com/bug?id=cd662bc3f6022c0979d01a262c318fab2ee9b56f
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <bot+48594378e9851eab70bcd6f99327c7db58c5a28a@syzkaller.appspotmail.com>
Fixes: ecdd09597a572513 ("block/loop: fix race between I/O and set_status")
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d037577c323e5090ce281e96bc313ab2eee5be2 upstream.
The following commit:
commit aa4d86163e4e ("block: loop: switch to VFS ITER_BVEC")
replaced __do_lo_send_write(), which used ITER_KVEC iterators, with
lo_write_bvec() which uses ITER_BVEC iterators. In this change, though,
the WRITE flag was lost:
- iov_iter_kvec(&from, ITER_KVEC | WRITE, &kvec, 1, len);
+ iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len);
This flag is necessary for the DAX case because we make decisions based on
whether or not the iterator is a READ or a WRITE in dax_iomap_actor() and
in dax_iomap_rw().
We end up going through this path in configurations where we combine a PMEM
device with 4k sectors, a loopback device and DAX. The consequence of this
missed flag is that what we intend as a write actually turns into a read in
the DAX code, so no data is ever written.
The very simplest test case is to create a loopback device and try and
write a small string to it, then hexdump a few bytes of the device to see
if the write took. Without this patch you read back all zeros, with this
you read back the string you wrote.
For XFS this causes us to fail or panic during the following xfstests:
xfs/074 xfs/078 xfs/216 xfs/217 xfs/250
For ext4 we have a similar issue where writes never happen, but we don't
currently have any xfstests that use loopback and show this issue.
Fix this by restoring the WRITE flag argument to iov_iter_bvec(). This
causes the xfstests to all pass.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Fixes: commit aa4d86163e4e ("block: loop: switch to VFS ITER_BVEC")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e573427a440fd67d3f522357d7ac901d59281948 upstream. This feature bit restricts older clients from performing certain maintenance operations against an image (e.g. clone, snap create). krbd does not perform maintenance operations. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Jason Dillaman <dillaman@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 882d4171a8950646413b1a3cbe0e4a6a612fe82e upstream.
Call bdev_get_queue(bdev) after bdev->bd_disk has been initialized
instead of just before that pointer has been initialized. This patch
avoids that the following command
pktsetup 1 /dev/sr0
triggers the following kernel crash:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000548
IP: pkt_setup_dev+0x2db/0x670 [pktcdvd]
CPU: 2 PID: 724 Comm: pktsetup Not tainted 4.15.0-rc4-dbg+ #1
Call Trace:
pkt_ctl_ioctl+0xce/0x1c0 [pktcdvd]
do_vfs_ioctl+0x8e/0x670
SyS_ioctl+0x3c/0x70
entry_SYSCALL_64_fastpath+0x23/0x9a
Reported-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Fixes: commit ca18d6f769d2 ("block: Make most scsi_req_init() calls implicit")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5a0ec388ef0f6e33841aeb810d7fa23f049ec4cd upstream.
Commit 523e1d399ce0 ("block: make gendisk hold a reference to its queue")
modified add_disk() and disk_release() but did not update any of the
error paths that trigger a put_disk() call after disk->queue has been
assigned. That introduced the following behavior in the pktcdvd driver
if pkt_new_dev() fails:
Kernel BUG at 00000000e98fd882 [verbose debug info unavailable]
Since disk_release() calls blk_put_queue() anyway if disk->queue != NULL,
fix this by removing the blk_cleanup_queue() call from the pkt_setup_dev()
error path.
Fixes: commit 523e1d399ce0 ("block: make gendisk hold a reference to its queue")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull ceph fixes from Ilya Dryomov: "Two rbd fixes for 4.12 and 4.2 issues respectively, marked for stable" * tag 'ceph-for-4.15-rc8' of git://github.com/ceph/ceph-client: rbd: set max_segments to USHRT_MAX rbd: reacquire lock should update lock owner client id
Commit d3834fefcfe5 ("rbd: bump queue_max_segments") bumped
max_segments (unsigned short) to max_hw_sectors (unsigned int).
max_hw_sectors is set to the number of 512-byte sectors in an object
and overflows unsigned short for 32M (largest possible) objects, making
the block layer resort to handing us single segment (i.e. single page
or even smaller) bios in that case.
Cc: stable@vger.kernel.org
Fixes: d3834fefcfe5 ("rbd: bump queue_max_segments")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Otherwise, future operations on this RBD using exclusive-lock are
going to require the lock from a non-existent client id.
Cc: stable@vger.kernel.org
Fixes: 14bb211d324d ("rbd: support updating the lock cookie without releasing the lock")
Link: http://tracker.ceph.com/issues/19929
Signed-off-by: Florian Margaine <florian@platform.sh>
[idryomov@gmail.com: rbd_set_owner_cid() call, __rbd_lock() helper]
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
范龙飞 reports that KASAN can report a use-after-free in __lock_acquire. The reason is due to insufficient serialization in lo_release(), which will continue to use the loop device even after it has decremented the lo_refcnt to zero. In the meantime, another process can come in, open the loop device again as it is being shut down. Confusion ensues. Reported-by: 范龙飞 <long7573@126.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 966a967116e6 randomly added alignment to this structure, but
it's actually detrimental to performance of null_blk. Test case:
Running on both the home and remote node shows a ~5% degradation
in performance.
While in there, move blk_status_t to the hole after the integer tag
in the nullb_cmd structure. After this patch, we shrink the size
from 192 to 152 bytes.
Fixes: 966a967116e69 ("smp: Avoid using two cache lines for struct call_single_data")
Signed-off-by: Jens Axboe <axboe@kernel.dk>