linux-stable.git/block, branch v6.4.9

blk-mq: Fix stall due to recursive flush plug

2023-08-03T08:25:41+00:00

[ Upstream commit 70904263512a74a3b8941dd9e6e515ca6fc57821 ]

We have seen rare IO stalls as follows:

* blk_mq_plug_issue_direct() is entered with an mq_list containing two
requests.
* For the first request, it sets last == false and enters the driver's
queue_rq callback.
* The driver queue_rq callback indirectly calls schedule() which calls
blk_flush_plug(). This may happen if the driver has the
BLK_MQ_F_BLOCKING flag set and is allowed to sleep in ->queue_rq.
* blk_flush_plug() handles the remaining request in the mq_list. mq_list
is now empty.
* The original call to queue_rq resumes (with last == false).
* The loop in blk_mq_plug_issue_direct() terminates because there are no
remaining requests in mq_list.

The IO is now stalled because the last request submitted to the driver
had last == false and there was no subsequent call to commit_rqs().

Fix this by returning early in blk_mq_flush_plug_list() if rq_count is 0
which it will be in the recursive case, rather than checking if the
mq_list is empty. At the same time, adjust one of the callers to skip
the mq_list empty check as it is not necessary.

Fixes: dc5fc361d891 ("block: attempt direct issue of plug list")
Signed-off-by: Ross Lagerwall 
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20230714101106.3635611-1-ross.lagerwall@citrix.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none

2023-07-27T06:56:45+00:00

[ Upstream commit 245165658e1c9f95c0fecfe02b9b1ebd30a1198a ]

After grabbing q->sysfs_lock, q->elevator may become NULL because of
elevator switch.

Fix the NULL dereference on q->elevator by checking it with lock.

Reported-by: Guangwu Zhang 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20230616132354.415109-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

blk-crypto: use dynamic lock class for blk_crypto_profile::lock

2023-07-23T11:53:39+00:00

[ Upstream commit 2fb48d88e77f29bf9d278f25bcfe82cf59a0e09b ]

When a device-mapper device is passing through the inline encryption
support of an underlying device, calls to blk_crypto_evict_key() take
the blk_crypto_profile::lock of the device-mapper device, then take the
blk_crypto_profile::lock of the underlying device (nested).  This isn't
a real deadlock, but it causes a lockdep report because there is only
one lock class for all instances of this lock.

Lockdep subclasses don't really work here because the hierarchy of block
devices is dynamic and could have more than 2 levels.

Instead, register a dynamic lock class for each blk_crypto_profile, and
associate that with the lock.

This avoids false-positive lockdep reports like the following:

    ============================================
    WARNING: possible recursive locking detected
    6.4.0-rc5 #2 Not tainted
    --------------------------------------------
    fscryptctl/1421 is trying to acquire lock:
    ffffff80829ca418 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0x44/0x1c0

                   but task is already holding lock:
    ffffff8086b68ca8 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0xc8/0x1c0

                   other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(&profile->lock);
      lock(&profile->lock);

                    *** DEADLOCK ***

     May be due to missing lock nesting notation

Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
Reported-by: Bart Van Assche 
Signed-off-by: Eric Biggers 
Reviewed-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20230610061139.212085-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block/partition: fix signedness issue for Amiga partitions

2023-07-19T14:37:03+00:00

commit 7eb1e47696aa231b1a567846bbe3a1e1befe1854 upstream.

Making 'blk' sector_t (i.e. 64 bit if LBD support is active) fails the
'blk>0' test in the partition block loop if a value of (signed int) -1 is
used to mark the end of the partition block list.

Explicitly cast 'blk' to signed int to allow use of -1 to terminate the
partition block linked list.

Fixes: b6f3f28f604b ("block: add overflow checks for Amiga partition support")
Reported-by: Christian Zigotzky 
Link: https://lore.kernel.org/r/024ce4fa-cc6d-50a2-9aae-3701d0ebf668@xenosoft.de
Signed-off-by: Michael Schmitz 
Reviewed-by: Martin Steigerwald 
Tested-by: Christian Zigotzky 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-throttle: Fix io statistics for cgroup v1

2023-07-19T14:36:40+00:00

[ Upstream commit ad7c3b41e86b59943a903d23c7b037d820e6270c ]

After commit f382fb0bcef4 ("block: remove legacy IO schedulers"),
blkio.throttle.io_serviced and blkio.throttle.io_service_bytes become
the only stable io stats interface of cgroup v1, and these statistics
are done in the blk-throttle code. But the current code only counts the
bios that are actually throttled. When the user does not add the throttle
limit, the io stats for cgroup v1 has nothing. I fix it according to the
statistical method of v2, and made it count all ios accurately.

Fixes: a7b36ee6ba29 ("block: move blk-throtl fast path inline")
Tested-by: Andrea Righi 
Signed-off-by: Jinke Han 
Acked-by: Muchun Song 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230507170631.89607-1-hanjinke.666@bytedance.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: increment diskseq on all media change events

2023-07-19T14:36:22+00:00

commit b90ecc0379eb7bbe79337b0c7289390a98752646 upstream.

Currently, associating a loop device with a different file descriptor
does not increment its diskseq.  This allows the following race
condition:

1. Program X opens a loop device
2. Program X gets the diskseq of the loop device.
3. Program X associates a file with the loop device.
4. Program X passes the loop device major, minor, and diskseq to
   something.
5. Program X exits.
6. Program Y detaches the file from the loop device.
7. Program Y attaches a different file to the loop device.
8. The opener finally gets around to opening the loop device and checks
   that the diskseq is what it expects it to be.  Even though the
   diskseq is the expected value, the result is that the opener is
   accessing the wrong file.

From discussions with Christoph Hellwig, it appears that
disk_force_media_change() was supposed to call inc_diskseq(), but in
fact it does not.  Adding a Fixes: tag to indicate this.  Christoph's
Reported-by is because he stated that disk_force_media_change()
calls inc_diskseq(), which is what led me to discover that it should but
does not.

Reported-by: Christoph Hellwig 
Signed-off-by: Demi Marie Obenour 
Fixes: e6138dc12de9 ("block: add a helper to raise a media changed event")
Cc: stable@vger.kernel.org # 5.15+
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230607170837.1559-1-demi@invisiblethingslab.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: add overflow checks for Amiga partition support

2023-07-19T14:36:22+00:00

commit b6f3f28f604ba3de4724ad82bea6adb1300c0b5f upstream.

The Amiga partition parser module uses signed int for partition sector
address and count, which will overflow for disks larger than 1 TB.

Use u64 as type for sector address and size to allow using disks up to
2 TB without LBD support, and disks larger than 2 TB with LBD. The RBD
format allows to specify disk sizes up to 2^128 bytes (though native
OS limitations reduce this somewhat, to max 2^68 bytes), so check for
u64 overflow carefully to protect against overflowing sector_t.

Bail out if sector addresses overflow 32 bits on kernels without LBD
support.

This bug was reported originally in 2012, and the fix was created by
the RDB author, Joanne Dow . A patch had been
discussed and reviewed on linux-m68k at that time but never officially
submitted (now resubmitted as patch 1 in this series).
This patch adds additional error checking and warning messages.

Reported-by: Martin Steigerwald 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=43511
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Message-ID: <201206192146.09327.Martin@lichtvoll.de>
Cc:  # 5.2
Signed-off-by: Michael Schmitz 
Reviewed-by: Geert Uytterhoeven 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230620201725.7020-4-schmitzmic@gmail.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: fix signed int overflow in Amiga partition support

2023-07-19T14:36:21+00:00

commit fc3d092c6bb48d5865fec15ed5b333c12f36288c upstream.

The Amiga partition parser module uses signed int for partition sector
address and count, which will overflow for disks larger than 1 TB.

Use sector_t as type for sector address and size to allow using disks
up to 2 TB without LBD support, and disks larger than 2 TB with LBD.

This bug was reported originally in 2012, and the fix was created by
the RDB author, Joanne Dow . A patch had been
discussed and reviewed on linux-m68k at that time but never officially
submitted. This patch differs from Joanne's patch only in its use of
sector_t instead of unsigned int. No checking for overflows is done
(see patch 3 of this series for that).

Reported-by: Martin Steigerwald 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=43511
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Message-ID: <201206192146.09327.Martin@lichtvoll.de>
Cc:  # 5.2
Signed-off-by: Michael Schmitz 
Tested-by: Martin Steigerwald 
Reviewed-by: Geert Uytterhoeven 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230620201725.7020-2-schmitzmic@gmail.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-mq: don't insert passthrough request into sw queue

2023-07-19T14:35:14+00:00

[ Upstream commit 2293cae703cda162684ae966db6b1b4a11b5e88f ]

In case of real io scheduler, q->elevator is set, so blk_mq_run_hw_queue()
may just check if scheduler queue has request to dispatch, see
__blk_mq_sched_dispatch_requests(). Then IO hang may be caused because
all passthorugh requests may stay in sw queue.

And any passthrough request should have been inserted to hctx->dispatch
always.

Reported-by: Guangwu Zhang 
Fixes: d97217e7f024 ("blk-mq: don't queue plugged passthrough requests into scheduler")
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20230621132208.1142318-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: fix blktrace debugfs entries leakage

2023-07-19T14:35:11+00:00

[ Upstream commit dd7de3704af9989b780693d51eaea49a665bd9c2 ]

Commit 99d055b4fd4b ("block: remove per-disk debugfs files in
blk_unregister_queue") moves blk_trace_shutdown() from
blk_release_queue() to blk_unregister_queue(), this is safe if blktrace
is created through sysfs, however, there is a regression in corner
case.

blktrace can still be enabled after del_gendisk() through ioctl if
the disk is opened before del_gendisk(), and if blktrace is not shutdown
through ioctl before closing the disk, debugfs entries will be leaked.

Fix this problem by shutdown blktrace in disk_release(), this is safe
because blk_trace_remove() is reentrant.

Fixes: 99d055b4fd4b ("block: remove per-disk debugfs files in blk_unregister_queue")
Signed-off-by: Yu Kuai 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230610022003.2557284-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin