linux.git/drivers/block, branch v6.1.48

rbd: prevent busy loop when requesting exclusive lock

2023-08-11T10:08:21+00:00

commit 9d01e07fd1bfb4daae156ab528aa196f5ac2b2bc upstream.

Due to rbd_try_acquire_lock() effectively swallowing all but
EBLOCKLISTED error from rbd_try_lock() ("request lock anyway") and
rbd_request_lock() returning ETIMEDOUT error not only for an actual
notify timeout but also when the lock owner doesn't respond, a busy
loop inside of rbd_acquire_lock() between rbd_try_acquire_lock() and
rbd_request_lock() is possible.

Requesting the lock on EBUSY error (returned by get_lock_owner_info()
if an incompatible lock or invalid lock owner is detected) makes very
little sense.  The same goes for ETIMEDOUT error (might pop up pretty
much anywhere if osd_request_timeout option is set) and many others.

Just fail I/O requests on rbd_dev->acquiring_list immediately on any
error from rbd_try_lock().

Cc: stable@vger.kernel.org # 588159009d5b: rbd: retrieve and check lock owner twice before blocklisting
Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang 
Signed-off-by: Greg Kroah-Hartman

rbd: retrieve and check lock owner twice before blocklisting

2023-08-03T08:24:17+00:00

commit 588159009d5b7a09c3e5904cffddbe4a4e170301 upstream.

An attempt to acquire exclusive lock can race with the current lock
owner closing the image:

1. lock is held by client123, rbd_lock() returns -EBUSY
2. get_lock_owner_info() returns client123 instance details
3. client123 closes the image, lock is released
4. find_watcher() returns 0 as there is no matching watcher anymore
5. client123 instance gets erroneously blocklisted

Particularly impacted is mirror snapshot scheduler in snapshot-based
mirroring since it happens to open and close images a lot (images are
opened only for as long as it takes to take the next mirror snapshot,
the same client instance is used for all images).

To reduce the potential for erroneous blocklisting, retrieve the lock
owner again after find_watcher() returns 0.  If it's still there, make
sure it matches the previously detected lock owner.

Cc: stable@vger.kernel.org # f38cb9d9c204: rbd: make get_lock_owner_info() return a single locker or NULL
Cc: stable@vger.kernel.org # 8ff2c64c9765: rbd: harden get_lock_owner_info() a bit
Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang 
Signed-off-by: Greg Kroah-Hartman

rbd: harden get_lock_owner_info() a bit

2023-08-03T08:24:17+00:00

commit 8ff2c64c9765446c3cef804fb99da04916603e27 upstream.

- we want the exclusive lock type, so test for it directly
- use sscanf() to actually parse the lock cookie and avoid admitting
  invalid handles
- bail if locker has a blank address

Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang 
Signed-off-by: Greg Kroah-Hartman

rbd: make get_lock_owner_info() return a single locker or NULL

2023-08-03T08:24:17+00:00

commit f38cb9d9c2045dad16eead4a2e1aedfddd94603b upstream.

Make the "num_lockers can be only 0 or 1" assumption explicit and
simplify the API by getting rid of output parameters in preparation
for calling get_lock_owner_info() twice before blocklisting.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang 
Signed-off-by: Greg Kroah-Hartman

ublk: fail to recover device if queue setup is interrupted

2023-08-03T08:24:07+00:00

[ Upstream commit 0c0cbd4ebc375ceebc75c89df04b74f215fab23a ]

In ublk_ctrl_end_recovery(), if wait_for_completion_interruptible() is
interrupted by signal, queues aren't setup successfully yet, so we
have to fail UBLK_CMD_END_USER_RECOVERY, otherwise kernel oops can be
triggered.

Fixes: c732a852b419 ("ublk_drv: add START_USER_RECOVERY and END_USER_RECOVERY support")
Reported-by: Stefano Garzarella 
Signed-off-by: Ming Lei 
Reviewed-by: Stefano Garzarella 
Link: https://lore.kernel.org/r/20230726144502.566785-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

ublk: fail to start device if queue setup is interrupted

2023-08-03T08:24:06+00:00

[ Upstream commit 53e7d08f6d6e214c40db1f51291bb2975c789dc2 ]

In ublk_ctrl_start_dev(), if wait_for_completion_interruptible() is
interrupted by signal, queues aren't setup successfully yet, so we
have to fail UBLK_CMD_START_DEV, otherwise kernel oops can be triggered.

Reported by German when working on qemu-storage-deamon which requires
single thread ublk daemon.

Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Reported-by: German Maglione 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20230726144502.566785-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

ublk_drv: move ublk_get_device_from_id into ublk_ctrl_uring_cmd

2023-08-03T08:24:06+00:00

[ Upstream commit bfbcef036396a73fbf4b3fee385cc670159df5ad ]

It is annoying for each control command handler to get/put ublk
device and deal with failure.

Control command handler is simplified a lot by moving
ublk_get_device_from_id into ublk_ctrl_uring_cmd().

Reviewed-by: ZiyangZhang 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20230106041711.914434-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Stable-dep-of: 53e7d08f6d6e ("ublk: fail to start device if queue setup is interrupted")
Signed-off-by: Sasha Levin

null_blk: Fix: memory release when memory_backed=1

2023-06-28T09:12:39+00:00

[ Upstream commit 8cfb98196cceec35416041c6b91212d2b99392e4 ]

Memory/pages are not freed, when unloading nullblk driver.

Steps to reproduce issue
  1.free -h
        total        used        free      shared  buff/cache   available
Mem:    7.8Gi       260Mi       7.1Gi       3.0Mi       395Mi       7.3Gi
Swap:      0B          0B          0B
  2.modprobe null_blk memory_backed=1
  3.dd if=/dev/urandom of=/dev/nullb0 oflag=direct bs=1M count=1000
  4.modprobe -r null_blk
  5.free -h
        total        used        free      shared  buff/cache   available
Mem:    7.8Gi       1.2Gi       6.1Gi       3.0Mi       398Mi       6.3Gi
Swap:      0B          0B          0B

Signed-off-by: Anuj Gupta 
Signed-off-by: Nitesh Shetty 
Link: https://lore.kernel.org/r/20230605062354.24785-1-nj.shetty@samsung.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

xen/blkfront: Only check REQ_FUA for writes

2023-06-21T14:00:53+00:00

[ Upstream commit b6ebaa8100090092aa602530d7e8316816d0c98d ]

The existing code silently converts read operations with the
REQ_FUA bit set into write-barrier operations. This results in data
loss as the backend scribbles zeroes over the data instead of returning
it.

While the REQ_FUA bit doesn't make sense on a read operation, at least
one well-known out-of-tree kernel module does set it and since it
results in data loss, let's be safe here and only look at REQ_FUA for
writes.

Signed-off-by: Ross Lagerwall 
Acked-by: Juergen Gross 
Link: https://lore.kernel.org/r/20230426164005.2213139-1-ross.lagerwall@citrix.com
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin

rbd: get snapshot context after exclusive lock is ensured to be held

2023-06-14T09:15:28+00:00

commit 870611e4877eff1e8413c3fb92a585e45d5291f6 upstream.

Move capturing the snapshot context into the image request state
machine, after exclusive lock is ensured to be held for the duration of
dealing with the image request.  This is needed to ensure correctness
of fast-diff states (OBJECT_EXISTS vs OBJECT_EXISTS_CLEAN) and object
deltas computed based off of them.  Otherwise the object map that is
forked for the snapshot isn't guaranteed to accurately reflect the
contents of the snapshot when the snapshot is taken under I/O.  This
breaks differential backup and snapshot-based mirroring use cases with
fast-diff enabled: since some object deltas may be incomplete, the
destination image may get corrupted.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/61472
Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang 
Signed-off-by: Greg Kroah-Hartman