A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 89e524c0 ("loop: Fix mount(2) failure due to race with
LOOP_SET_FD") converted blkdev_get() to use the new helpers for
finishing claiming of a block device. However the conversion botched the
error handling in blkdev_get() and thus the bdev has been marked as held
even in case __blkdev_get() returned error. This led to occasional
warnings with block/001 test from blktests like:

kernel: WARNING: CPU: 5 PID: 907 at fs/block_dev.c:1899 __blkdev_put+0x396/0x3a0

Correct the error handling.

CC: stable@vger.kernel.org
Fixes: 89e524c0 ("loop: Fix mount(2) failure due to race with LOOP_SET_FD")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

As reported in [1], the call bfq_init_rq(rq) may return NULL in case
of OOM (in particular, if rq->elv.icq is NULL because memory
allocation failed in failed in ioc_create_icq()).

This commit handles this circumstance.

[1] https://lkml.org/lkml/2019/7/22/824

Cc: Hsin-Yi Wang <hsinyi@google.com>
Cc: Nicolas Boichat <drinkcat@chromium.org>
Cc: Doug Anderson <dianders@chromium.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Hsin-Yi Wang <hsinyi@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 13a857a4 ("block, bfq: detect wakers and
unconditionally inject their I/O"), every bfq_queue has a pointer to a
waker bfq_queue and a list of the bfq_queues it may wake. In this
respect, when a bfq_queue, say Q, remains with no I/O source attached
to it, Q cannot be woken by any other bfq_queue, and cannot wake any
other bfq_queue. Then Q must be removed from the woken list of its
possible waker bfq_queue, and all bfq_queues in the woken list of Q
must stop having a waker bfq_queue.

Q remains with no I/O source in two cases: when the last process
associated with Q exits or when such a process gets associated with a
different bfq_queue. Unfortunately, commit 13a857a4 ("block, bfq:
detect wakers and unconditionally inject their I/O") performed the
above updates only in the first case.

This commit fixes this bug by moving these updates to when Q gets
freed. This is a simple and safe way to handle all cases, as both the
above events, process exit and re-association, lead to Q being freed
soon, and because dangling references would come out only after Q gets
freed (if no update were performed).

Fixes: 13a857a4 ("block, bfq: detect wakers and unconditionally inject their I/O")
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 13a857a4 ("block, bfq: detect wakers and
unconditionally inject their I/O"), BFQ stores, in a per-device
pointer last_completed_rq_bfqq, the last bfq_queue that had an I/O
request completed. If some bfq_queue receives new I/O right after the
last request of last_completed_rq_bfqq has been completed, then
last_completed_rq_bfqq may be a waker bfq_queue.

But if the bfq_queue last_completed_rq_bfqq points to is freed, then
last_completed_rq_bfqq becomes a dangling reference. This commit
resets last_completed_rq_bfqq if the pointed bfq_queue is freed.

Fixes: 13a857a4 ("block, bfq: detect wakers and unconditionally inject their I/O")
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 3582dd29 ("aoe: convert aoeblk to blk-mq"), aoedev_downdev
has had the possibility of sleeping and causing the following crash.

BUG: scheduling while atomic: rmmod/2242/0x00000003
Modules linked in: aoe
Preemption disabled at:
[<ffffffffc01d95e5>] flush+0x95/0x4a0 [aoe]
CPU: 7 PID: 2242 Comm: rmmod Tainted: G          I       5.2.3 #1
Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009
Call Trace:
 dump_stack+0x4f/0x6a
 ? flush+0x95/0x4a0 [aoe]
 __schedule_bug.cold+0x44/0x54
 __schedule+0x44f/0x680
 schedule+0x44/0xd0
 blk_mq_freeze_queue_wait+0x46/0xb0
 ? wait_woken+0x80/0x80
 blk_mq_freeze_queue+0x1b/0x20
 aoedev_downdev+0x111/0x160 [aoe]
 flush+0xff/0x4a0 [aoe]
 aoedev_exit+0x23/0x30 [aoe]
 aoe_exit+0x35/0x948 [aoe]
 __se_sys_delete_module+0x183/0x210
 __x64_sys_delete_module+0x16/0x20
 do_syscall_64+0x4d/0x130
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f24e0043b07
Code: 73 01 c3 48 8b 0d 89 73 0b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f
1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 01 c3 48 8b 0d 59 73 0b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe18f7f1e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f24e0043b07
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000555c3ecf87c8
RBP: 00007ffe18f7f1f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f24e00b4ac0 R11: 0000000000000206 R12: 00007ffe18f7f238
R13: 00007ffe18f7f410 R14: 00007ffe18f80e73 R15: 0000555c3ecf8760

This patch, handling in the same way of pass two, unlocks the locks and
restart pass one after aoedev_downdev is done.

Fixes: 3582dd29 ("aoe: convert aoeblk to blk-mq")
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Abort processing of a command if we run out of mapped data in the
SG list. This should never happen, but a previous bug caused it to
be possible. Play it safe and attempt to abort nicely if we don't
have more SG segments left.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

For passthrough requests, libata-scsi takes what the user passes in
as gospel. This can be problematic if the user fills in the CDB
incorrectly. One example of that is in request sizes. For read/write
commands, the CDB contains fields describing the transfer length of
the request. These should match with the SG_IO header fields, but
libata-scsi currently does no validation of that.

Check that the number of blocks in the CDB for passthrough requests
matches what was mapped into the request. If the CDB asks for more
data then the validated SG_IO header fields, error it.
Reported-by: Krishna Ram Prakash R <krp@gtux.in>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

0eb6ddfb tried to fix this up, but introduced a use-after-free
of dio. Additionally, we still had an issue with error handling,
as reported by Darrick:

"I noticed a regression in xfs/747 (an unreleased xfstest for the
xfs_scrub media scanning feature) on 5.3-rc3.  I'll condense that down
to a simpler reproducer:

error-test: 0 209 linear 8:48 0
error-test: 209 1 error
error-test: 210 6446894 linear 8:48 210

Basically we have a ~3G /dev/sdd and we set up device mapper to fail IO
for sector 209 and to pass the io to the scsi device everywhere else.

On 5.3-rc3, performing a directio pread of this range with a < 1M buffer
(in other words, a request for fewer than MAX_BIO_PAGES bytes) yields
EIO like you'd expect:

pread64(3, 0x7f880e1c7000, 1048576, 0)  = -1 EIO (Input/output error)
pread: Input/output error
+++ exited with 0 +++

But doing it with a larger buffer succeeds(!):

pread64(3, "XFSB\0\0\20\0\0\0\0\0\0\fL\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1146880, 0) = 1146880
read 1146880/1146880 bytes at offset 0
1 MiB, 1 ops; 0.0009 sec (1.124 GiB/sec and 1052.6316 ops/sec)
+++ exited with 0 +++

(Note that the part of the buffer corresponding to the dm-error area is
uninitialized)

On 5.3-rc2, both commands would fail with EIO like you'd expect.  The
only change between rc2 and rc3 is commit 0eb6ddfb ("block: Fix
__blkdev_direct_IO() for bio fragments").

AFAICT we end up in __blkdev_direct_IO with a 1120K buffer, which gets
split into two bios: one for the first BIO_MAX_PAGES worth of data (1MB)
and a second one for the 96k after that."

Fix this by noting that it's always safe to dereference dio if we get
BLK_QC_T_EAGAIN returned, as end_io hasn't been run for that case. So
we can safely increment the dio size before calling submit_bio(), and
then decrement it on failure (not that it really matters, as the bio
and dio are going away).

For error handling, return to the original method of just using 'ret'
for tracking the error, and the size tracking in dio->size.

Fixes: 0eb6ddfb ("block: Fix __blkdev_direct_IO() for bio fragments")
Fixes: 6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Fix the following warning (Building: rb532_defconfig mips):

drivers/ata/pata_rb532_cf.c: In function ‘rb532_pata_driver_remove’:
drivers/ata/pata_rb532_cf.c:161:24: warning: unused variable ‘info’ [-Wunused-variable]
  struct rb532_cf_info *info = ah->private_data;
                        ^~~~

Fixes: cd56f35e ("ata: rb532_cf: Convert to use GPIO descriptors")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

After getting a storage server event that causes the DASD device driver
to update its unit address configuration during a device shutdown there is
the possibility of an endless loop in the device driver.

In the system log there will be ongoing DASD error messages with RC: -19.

The reason is that the loop starting the ruac request only terminates when
the retry counter is decreased to 0. But in the sleep_on function there are
early exit paths that do not decrease the retry counter.

Prevent an endless loop by handling those cases separately.

Remove the unnecessary do..while loop since the sleep_on function takes
care of retries by itself.

Fixes: 8e09f215 ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org # 2.6.25+
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The recent fix to properly handle IOCB_NOWAIT for async O_DIRECT IO
(patch 6a43074e) introduced two problems with BIO fragment handling
for direct IOs:
1) The dio size processed is calculated by incrementing the ret variable
by the size of the bio fragment issued for the dio. However, this size
is obtained directly from bio->bi_iter.bi_size AFTER the bio submission
which may result in referencing the bi_size value after the bio
completed, resulting in an incorrect value use.
2) The ret variable is not incremented by the size of the last bio
fragment issued for the bio, leading to an invalid IO size being
returned to the user.

Fix both problem by using dio->size (which is incremented before the bio
submission) to update the value of ret after bio submissions, including
for the last bio fragment issued.

Fixes: 6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
Reported-by: Masato Suzuki <masato.suzuki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

I would like to maintain the floppy driver. After the recent fixes,
I think I know the code pretty well. Nowadays I've got 2 physical 3.5"
readers to test all the changes.
Signed-off-by: Denis Efremov <efremov@linux.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit abbbdf12 ("replace kill_bdev() with __invalidate_device()")
once did this, but 29eaadc0 ("nbd: stop using the bdev everywhere")
resurrected kill_bdev() and it has been there since then. So buffer_head
mappings still get killed on a server disconnection, and we can still
hit the BUG_ON on a filesystem on the top of the nbd device.

  EXT4-fs (nbd0): mounted filesystem with ordered data mode. Opts: (null)
  block nbd0: Receive control failed (result -32)
  block nbd0: shutting down sockets
  print_req_error: I/O error, dev nbd0, sector 66264 flags 3000
  EXT4-fs warning (device nbd0): htree_dirblock_to_tree:979: inode #2: lblock 0: comm ls: error -5 reading directory block
  print_req_error: I/O error, dev nbd0, sector 2264 flags 3000
  EXT4-fs error (device nbd0): __ext4_get_inode_loc:4690: inode #2: block 283: comm ls: unable to read itable block
  EXT4-fs error (device nbd0) in ext4_reserve_inode_write:5894: IO failure
  ------------[ cut here ]------------
  kernel BUG at fs/buffer.c:3057!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 7 PID: 40045 Comm: jbd2/nbd0-8 Not tainted 5.1.0-rc3+ #4
  Hardware name: Amazon EC2 m5.12xlarge/, BIOS 1.0 10/16/2017
  RIP: 0010:submit_bh_wbc+0x18b/0x190
  ...
  Call Trace:
   jbd2_write_superblock+0xf1/0x230 [jbd2]
   ? account_entity_enqueue+0xc5/0xf0
   jbd2_journal_update_sb_log_tail+0x94/0xe0 [jbd2]
   jbd2_journal_commit_transaction+0x12f/0x1d20 [jbd2]
   ? __switch_to_asm+0x40/0x70
   ...
   ? lock_timer_base+0x67/0x80
   kjournald2+0x121/0x360 [jbd2]
   ? remove_wait_queue+0x60/0x60
   kthread+0xf8/0x130
   ? commit_timeout+0x10/0x10 [jbd2]
   ? kthread_bind+0x10/0x10
   ret_from_fork+0x35/0x40

With __invalidate_device(), I no longer hit the BUG_ON with sync or
unmount on the disconnected device.

Fixes: 29eaadc0 ("nbd: stop using the bdev everywhere")
Cc: linux-block@vger.kernel.org
Cc: Ratna Manoj Bolla <manoj.br@gmail.com>
Cc: nbd@other.debian.org
Cc: stable@vger.kernel.org
Cc: David Woodhouse <dwmw@amazon.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Retrieving PHYs can defer the probe, do not spawn an error when
-EPROBE_DEFER is returned, it is normal behavior.

Fixes: b1a9edbd ("ata: libahci: allow to use multiple PHYs")
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

[root@localhost ~]# ./liburing/test/link

QEMU Standard PC report that:

[   29.379892] CPU: 0 PID: 84 Comm: kworker/u2:2 Not tainted 5.3.0-rc2-00051-g4010b622-dirty #86
[   29.379902] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[   29.379913] Workqueue: io_ring-wq io_sq_wq_submit_work
[   29.379929] Call Trace:
[   29.379953]  dump_stack+0xa9/0x10e
[   29.379970]  ? io_sq_wq_submit_work+0xbf4/0xe90
[   29.379986]  print_address_description.cold.6+0x9/0x317
[   29.379999]  ? io_sq_wq_submit_work+0xbf4/0xe90
[   29.380010]  ? io_sq_wq_submit_work+0xbf4/0xe90
[   29.380026]  __kasan_report.cold.7+0x1a/0x34
[   29.380044]  ? io_sq_wq_submit_work+0xbf4/0xe90
[   29.380061]  kasan_report+0xe/0x12
[   29.380076]  io_sq_wq_submit_work+0xbf4/0xe90
[   29.380104]  ? io_sq_thread+0xaf0/0xaf0
[   29.380152]  process_one_work+0xb59/0x19e0
[   29.380184]  ? pwq_dec_nr_in_flight+0x2c0/0x2c0
[   29.380221]  worker_thread+0x8c/0xf40
[   29.380248]  ? __kthread_parkme+0xab/0x110
[   29.380265]  ? process_one_work+0x19e0/0x19e0
[   29.380278]  kthread+0x30b/0x3d0
[   29.380292]  ? kthread_create_on_node+0xe0/0xe0
[   29.380311]  ret_from_fork+0x3a/0x50

[   29.380635] Allocated by task 209:
[   29.381255]  save_stack+0x19/0x80
[   29.381268]  __kasan_kmalloc.constprop.6+0xc1/0xd0
[   29.381279]  kmem_cache_alloc+0xc0/0x240
[   29.381289]  io_submit_sqe+0x11bc/0x1c70
[   29.381300]  io_ring_submit+0x174/0x3c0
[   29.381311]  __x64_sys_io_uring_enter+0x601/0x780
[   29.381322]  do_syscall_64+0x9f/0x4d0
[   29.381336]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[   29.381633] Freed by task 84:
[   29.382186]  save_stack+0x19/0x80
[   29.382198]  __kasan_slab_free+0x11d/0x160
[   29.382210]  kmem_cache_free+0x8c/0x2f0
[   29.382220]  io_put_req+0x22/0x30
[   29.382230]  io_sq_wq_submit_work+0x28b/0xe90
[   29.382241]  process_one_work+0xb59/0x19e0
[   29.382251]  worker_thread+0x8c/0xf40
[   29.382262]  kthread+0x30b/0x3d0
[   29.382272]  ret_from_fork+0x3a/0x50

[   29.382569] The buggy address belongs to the object at ffff888067172140
                which belongs to the cache io_kiocb of size 224
[   29.384692] The buggy address is located 120 bytes inside of
                224-byte region [ffff888067172140, ffff888067172220)
[   29.386723] The buggy address belongs to the page:
[   29.387575] page:ffffea00019c5c80 refcount:1 mapcount:0 mapping:ffff88806ace5180 index:0x0
[   29.387587] flags: 0x100000000000200(slab)
[   29.387603] raw: 0100000000000200 dead000000000100 dead000000000122 ffff88806ace5180
[   29.387617] raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
[   29.387624] page dumped because: kasan: bad access detected

[   29.387920] Memory state around the buggy address:
[   29.388771]  ffff888067172080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[   29.390062]  ffff888067172100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
[   29.391325] >ffff888067172180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   29.392578]                                         ^
[   29.393480]  ffff888067172200: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
[   29.394744]  ffff888067172280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   29.396003] ==================================================================
[   29.397260] Disabling lock debugging due to kernel taint

io_sq_wq_submit_work free and read req again.

Cc: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Cc: linux-block@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: f7b76ac9 ("io_uring: fix counter inc/dec mismatch in async_list")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 33ec3e53 ("loop: Don't change loop device under exclusive
opener") made LOOP_SET_FD ioctl acquire exclusive block device reference
while it updates loop device binding. However this can make perfectly
valid mount(2) fail with EBUSY due to racing LOOP_SET_FD holding
temporarily the exclusive bdev reference in cases like this:

for i in {a..z}{a..z}; do
        dd if=/dev/zero of=$i.image bs=1k count=0 seek=1024
        mkfs.ext2 $i.image
        mkdir mnt$i
done

echo "Run"
for i in {a..z}{a..z}; do
        mount -o loop -t ext2 $i.image mnt$i &
done

Fix the problem by not getting full exclusive bdev reference in
LOOP_SET_FD but instead just mark the bdev as being claimed while we
update the binding information. This just blocks new exclusive openers
instead of failing them with EBUSY thus fixing the problem.

Fixes: 33ec3e53 ("loop: Don't change loop device under exclusive opener")
Cc: stable@vger.kernel.org
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Jeffrin reported a KASAN issue:

  BUG: KASAN: global-out-of-bounds in ata_exec_internal_sg+0x50f/0xc70
  Read of size 16 at addr ffffffff91f41f80 by task scsi_eh_1/149
  ...
  The buggy address belongs to the variable:
    cdb.48319+0x0/0x40

Much like commit 18c9a99b ("libata: zpodd: small read overflow in
eject_tray()"), this fixes a cdb[] buffer length, this time in
zpodd_get_mech_type():

We read from the cdb[] buffer in ata_exec_internal_sg(). It has to be
ATAPI_CDB_LEN (16) bytes long, but this buffer is only 12 bytes.
Reported-by: Jeffrin Jose T <jeffrin@rajagiritech.edu.in>
Fixes: afe75951 ("libata: identify and init ZPODD devices")
Link: https://lore.kernel.org/lkml/201907181423.E808958@keescook/Tested-by: Jeffrin Jose T <jeffrin@rajagiritech.edu.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warning (Building: m68k):

drivers/block/ataflop.c: In function ‘fd_locked_ioctl’:
drivers/block/ataflop.c:1728:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
   set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/block/ataflop.c:1729:2: note: here
  case FDFMTEND:
  ^~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull structleak fix from Kees Cook:
 "Disable gcc-based stack variable auto-init under KASAN (Arnd
  Bergmann).

  This fixes a bunch of build warnings under KASAN and the
  gcc-plugin-based stack auto-initialization features (which are
  arguably redundant, so better to let KASAN control this)"

* tag 'meminit-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  structleak: disable STRUCTLEAK_BYREF in combination with KASAN_STACK

Merge tag 'kbuild-fixes-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - add compile_commands.json to .gitignore

 - fix false-positive warning from gen_compile_commands.py after
   allnoconfig build

 - remove unused code

* tag 'kbuild-fixes-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: remove unused single-used-m
  gen_compile_commands: lower the entry count threshold
  .gitignore: Add compilation database file
  kbuild: remove unused objectify macro

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.3-rc2 to resolve
  some reported issues.

  Nothing major at all, some binder bugfixes for issues found, some new
  mei device ids, firmware building warning fixes, habanalabs fixes, a
  few other build fixes, and a MAINTAINERS update.

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  test_firmware: fix a memory leak bug
  hpet: Fix division by zero in hpet_time_div()
  eeprom: make older eeprom drivers select NVMEM_SYSFS
  vmw_balloon: Remove Julien from the maintainers list
  fpga-manager: altera-ps-spi: Fix build error
  mei: me: add mule creek canyon (EHL) device ids
  binder: prevent transactions to context manager from its own process.
  binder: Set end of SG buffer area properly.
  firmware: Fix missing inline
  firmware: fix build errors in paged buffer handling code
  habanalabs: don't reset device when getting VRHOT
  habanalabs: use %pad for printing a dma_addr_t

Pull tty fixes from Greg KH:
 "Here are two tty/vt fixes:

   - delete the netx-serial driver as the arch has been removed, no need
     to keep the serial driver for it around either.

   - vt console_lock fix to resolve a reported noisy warning at runtime

  Both of these have been in linux-next with no reported issues"

* tag 'tty-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt: Grab console_lock around con_is_bound in show_bind
  tty: serial: netx: Delete driver

Pull SPDX fixes from Greg KH:
 "Here are some small SPDX fixes for 5.3-rc2 for things that came in
  during the 5.3-rc1 merge window that we previously missed.

  Only three small patches here:

   - two uapi patches to resolve some SPDX tags that were not correct

   - fix an invalid SPDX tag in the iomap Makefile file

  All have been properly reviewed on the public mailing lists"

* tag 'spdx-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  iomap: fix Invalid License ID
  treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers again
  treewide: add "WITH Linux-syscall-note" to SPDX tag of uapi headers

Pull USB fixes from Greg KH:
 "Here are some small fixes for 5.3-rc2. All of these resolve some
  reported issues, some more than others :)

  Included in here is:

   - xhci fix for an annoying issue with odd devices

   - reversion of some usb251xb patches that should not have been merged

   - usb pci quirk additions and fixups

   - usb storage fix

   - usb host controller error test fix

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: Fix crash if scatter gather is used with Immediate Data Transfer (IDT).
  usb: usb251xb: Reallow swap-dx-lanes to apply to the upstream port
  Revert "usb: usb251xb: Add US port lanes inversion property"
  Revert "usb: usb251xb: Add US lanes inversion dts-bindings"
  usb: wusbcore: fix unbalanced get/put cluster_id
  usb/hcd: Fix a NULL vs IS_ERR() bug in usb_hcd_setup_local_mem()
  usb-storage: Add a limitation for blk_queue_max_hw_sectors()
  usb: pci-quirks: Minor cleanup for AMD PLL quirk
  usb: pci-quirks: Correct AMD PLL quirk detection

Pull ARM SoC fixes from Olof Johansson:
 "Here's the first batch of fixes for this release cycle.

  Main diffstat here is the re-deletion of netx. I messed up and most
  likely didn't remove the files from the index when I test-merged this
  and saw conflicts, and from there on out 'git rerere' remembered the
  mistake and I missed checking it. Here it's done again as expected.

  Besides that:

   - A defconfig refresh + enabling of new drivers for u8500

   - i.MX fixlets for i2c/SAI/pinmux

   - sleep.S build fix for Davinci

   - Broadcom devicetree build/warning fix"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: defconfig: u8500: Add new drivers
  ARM: defconfig: u8500: Refresh defconfig
  ARM: dts: bcm: bcm47094: add missing #cells for mdio-bus-mux
  ARM: davinci: fix sleep.S build error on ARMv4
  arm64: dts: imx8mq: fix SAI compatible
  arm64: dts: imx8mm: Correct SAI3 RXC/TXFS pin's mux option #1
  ARM: dts: imx6ul: fix clock frequency property name of I2C buses
  ARM: Delete netx a second time
  ARM: dts: imx7ulp: Fix usb-phy unit address format

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes and functional updates:

   - Prevent stale huge I/O TLB mappings on 32bit. A long standing bug
     which got exposed by KPTI support for 32bit

   - Prevent bogus access_ok() warnings in arch_stack_walk_user()

   - Add display quirks for Lenovo devices which have height and width
     swapped

   - Add the missing CR2 fixup for 32 bit async pagefaults. Fallout of
     the CR2 bug fix series.

   - Unbreak handling of force enabled HPET by moving the 'is HPET
     counting' check back to the original place.

   - A more accurate check for running on a hypervisor platform in the
     MDS mitigation code. Not perfect, but more accurate than the
     previous one.

   - Update a stale and confusing comment vs. IRQ stacks"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation/mds: Apply more accurate check on hypervisor platform
  x86/hpet: Undo the early counter is counting check
  x86/entry/32: Pass cr2 to do_async_page_fault()
  x86/irq/64: Update stale comment
  x86/sysfb_efi: Add quirks for some devices with swapped width and height
  x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user()
  mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()
  x86/mm: Sync also unmappings in vmalloc_sync_all()
  x86/mm: Check for pfn instead of page in vmalloc_sync_one()

Pull scheduler fixes from Thomas Gleixner:
 "Two fixes for the fair scheduling class:

   - Prevent freeing memory which is accessible by concurrent readers

   - Make the RCU annotations for numa groups consistent"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Use RCU accessors consistently for ->numa_group
  sched/fair: Don't free p->numa_faults with concurrent readers

Pull perf fixes from Thomas Gleixner:
 "A pile of perf related fixes:

  Kernel:
   - Fix SLOTS PEBS event constraints for Icelake CPUs

   - Add the missing mask bit to allow counting hardware generated
     prefetches on L3 for Icelake CPUs

   - Make the test for hypervisor platforms more accurate (as far as
     possible)

   - Handle PMUs correctly which override event->cpu

   - Yet another missing fallthrough annotation

  Tools:
     perf.data:
        - Fix loading of compressed data split across adjacent records
        - Fix buffer size setting for processing CPU topology perf.data
          header.

     perf stat:
        - Fix segfault for event group in repeat mode
        - Always separate "stalled cycles per insn" line, it was being
          appended to the "instructions" line.

     perf script:
        - Fix --max-blocks man page description.
        - Improve man page description of metrics.
        - Fix off by one in brstackinsn IPC computation.

     perf probe:
        - Avoid calling freeing routine multiple times for same pointer.

     perf build:
        - Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
          treated as errors, breaking the build"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Mark expected switch fall-throughs
  perf/core: Fix creating kernel counters for PMUs that override event->cpu
  perf/x86: Apply more accurate check on hypervisor platform
  perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x register
  perf/x86/intel: Fix SLOTS PEBS event constraint
  perf build: Do not use -Wshadow on gcc < 4.8
  perf probe: Avoid calling freeing routine multiple times for same pointer
  perf probe: Set pev->nargs to zero after freeing pev->args entries
  perf session: Fix loading of compressed data split across adjacent records
  perf stat: Always separate stalled cycles per insn
  perf stat: Fix segfault for event group in repeat mode
  perf tools: Fix proper buffer size for feature processing
  perf script: Fix off by one in brstackinsn IPC computation
  perf script: Improve man page description of metrics
  perf script: Fix --max-blocks man page description

Pull locking fixes from Thomas Gleixner:
 "A set of locking fixes:

   - Address the fallout of the rwsem rework. Missing ACQUIREs and a
     sanity check to prevent a use-after-free

   - Add missing checks for unitialized mutexes when mutex debugging is
     enabled.

   - Remove the bogus code in the generic SMP variant of
     arch_futex_atomic_op_inuser()

   - Fixup the #ifdeffery in lockdep to prevent compile warnings"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Test for initialized mutex
  locking/lockdep: Clean up #ifdef checks
  locking/lockdep: Hide unused 'class' variable
  locking/rwsem: Add ACQUIRE comments
  tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
  lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
  locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
  locking/rwsem: Don't call owner_on_cpu() on read-owner
  futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()

Pull objtool fix from Thomas Gleixner:
 "A single robustness fix for objtool to handle unbalanced CLAC
  invocations under all circumstances"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Improve UACCESS coverage

Merge tag 'Wimplicit-fallthrough-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull Wimplicit-fallthrough enablement from Gustavo A. R. Silva:
 "This marks switch cases where we are expecting to fall through, and
  globally enables the -Wimplicit-fallthrough option in the main
  Makefile.

  Finally, some missing-break fixes that have been tagged for -stable:

   - drm/amdkfd: Fix missing break in switch statement

   - drm/amdgpu/gfx10: Fix missing break in switch statement

  With these changes, we completely get rid of all the fall-through
  warnings in the kernel"

* tag 'Wimplicit-fallthrough-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  Makefile: Globally enable fall-through warning
  drm/i915: Mark expected switch fall-throughs
  drm/amd/display: Mark expected switch fall-throughs
  drm/amdkfd/kfd_mqd_manager_v10: Avoid fall-through warning
  drm/amdgpu/gfx10: Fix missing break in switch statement
  drm/amdkfd: Fix missing break in switch statement
  perf/x86/intel: Mark expected switch fall-throughs
  mtd: onenand_base: Mark expected switch fall-through
  afs: fsclient: Mark expected switch fall-throughs
  afs: yfsclient: Mark expected switch fall-throughs
  can: mark expected switch fall-throughs
  firewire: mark expected switch fall-throughs

Pull s390 updates from Heiko Carstens:

 - Add ABI to kernel image file which allows e.g. the file utility to
   figure out the kernel version.

 - Wire up clone3 system call.

 - Add support for kasan bitops instrumentation.

 - uapi header cleanup: use __u{16,32,64} instead of uint{16,32,64}_t.

 - Provide proper ARCH_ZONE_DMA_BITS so the s390 DMA zone is correctly
   defined with 2 GB instead of the default value of 1 MB.

 - Farhan Ali leaves the group of vfio-ccw maintainers.

 - Various small vfio-ccw fixes.

 - Add missing locking for airq_areas array in virtio code.

 - Minor qdio improvements.

* tag 's390-5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  MAINTAINERS: vfio-ccw: Remove myself as the maintainer
  s390/mm: use shared variables for sysctl range check
  virtio/s390: fix race on airq_areas[]
  s390/dma: provide proper ARCH_ZONE_DMA_BITS value
  s390/kasan: add bitops instrumentation
  s390/bitops: make test functions return bool
  s390: wire up clone3 system call
  kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test
  s390: use __u{16,32,64} instead of uint{16,32,64}_t in uapi header
  s390/hypfs: fix a typo in the name of a function
  s390/qdio: restrict QAOB usage to IQD unicast queues
  s390/qdio: add sanity checks to the fast-requeue path
  s390: enable detection of kernel version from bzImage
  Documentation: fix vfio-ccw doc
  vfio-ccw: Update documentation for csch/hsch
  vfio-ccw: Don't call cp_free if we are processing a channel program
  vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn
  vfio-ccw: Fix memory leak and don't call cp_free in cp_init
  vfio-ccw: Fix misleading comment when setting orb.cmd.c64

Pull Devicetree fixes from Rob Herring:
 "The nvmem changes would typically go thru Greg's tree, but they were
  missed in the merge window. [ Acked by Greg ]

  Summary:

   - Fix mismatches in $id values and actual filenames. Now checked by
     tools.

   - Convert nvmem binding to DT schema

   - Fix a typo in of_property_read_bool() kerneldoc

   - Remove some redundant description in al-fic interrupt-controller"

* tag 'devicetree-fixes-for-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: Fix more $id value mismatches filenames
  dt-bindings: nvmem: SID: Fix the examples node names
  dt-bindings: nvmem: Add YAML schemas for the generic NVMEM bindings
  of: Fix typo in kerneldoc
  dt-bindings: interrupt-controller: al-fic: remove redundant binding
  dt-bindings: clk: allwinner,sun4i-a10-ccu: Correct path in $id

Pull libnvdimm fixes from Dan Williams:
 "A collection of locking and async operations fixes for v5.3-rc2. These
  had been soaking in a branch targeting the merge window, but missed
  due to a regression hunt. This fixed up version has otherwise been in
  -next this past week with no reported issues.

  In order to gain confidence in the locking changes the pull also
  includes a debug / instrumentation patch to enable lockdep coverage
  for libnvdimm subsystem operations that depend on the device_lock for
  exclusion. As mentioned in the changelog it is a hack, but it works
  and documents the locking expectations of the sub-system in a way that
  others can use lockdep to verify. The driver core touches got an ack
  from Greg.

  Summary:

   - Fix duplicate device_unregister() calls (multiple threads competing
     to do unregister work when scheduling device removal from a sysfs
     attribute of the self-same device).

   - Fix badblocks registration order bug. Ensure region badblocks are
     initialized in advance of namespace registration.

   - Fix a deadlock between the bus lock and probe operations.

   - Export device-core infrastructure to coordinate async operations
     via the device ->dead state.

   - Add device-core infrastructure to validate device_lock() usage with
     lockdep"

* tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  driver-core, libnvdimm: Let device subsystems add local lockdep coverage
  libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock
  libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()
  libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant
  libnvdimm/region: Register badblocks before namespaces
  libnvdimm/bus: Prevent duplicate device_unregister() calls
  drivers/base: Introduce kill_device()

This is unused since commit 9f69a496 ("kbuild: split out *.mod out
of {single,multi}-used-m rules").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Running gen_compile_commands.py after building the kernel with
allnoconfig gave this:

$ ./scripts/gen_compile_commands.py
WARNING: Found 449 entries. Have you compiled the kernel?
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This file is used by clangd to use language server protocol.
It can be generated at each compile using scripts/gen_compile_commands.py.
Therefore it is different depending on the environment and should be
ignored.
Signed-off-by: Toru Komatsu <k0ma@utam0k.jp>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Commit 415008af ("docs-rst: convert lsm from DocBook to ReST")
removed the last users of this macro.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>