linux.git/block, branch v5.4.272

blk-mq: fix IO hang from sbitmap wakeup race

2024-02-23T07:25:03+00:00

[ Upstream commit 5266caaf5660529e3da53004b8b7174cab6374ed ]

In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered
with the following blk_mq_get_driver_tag() in case of getting driver
tag failure.

Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe
the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime
blk_mq_mark_tag_wait() can't get driver tag successfully.

This issue can be reproduced by running the following test in loop, and
fio hang can be observed in < 30min when running it on my test VM
in laptop.

	modprobe -r scsi_debug
	modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4
	dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
	fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \
       		--runtime=100 --numjobs=40 --time_based --name=test \
        	--ioengine=libaio

Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which
is just fine in case of running out of tag.

Cc: Jan Kara 
Cc: Kemeng Shi 
Reported-by: Changhui Zhong 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20240112122626.4181044-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: prevent an integer overflow in bvec_try_merge_hw_page

2024-02-23T07:24:59+00:00

[ Upstream commit 3f034c374ad55773c12dd8f3c1607328e17c0072 ]

Reordered a check to avoid a possible overflow when adding len to bv_len.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Link: https://lore.kernel.org/r/20231204173419.782378-2-hch@lst.de
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Remove special-casing of compound pages

2024-02-23T07:24:49+00:00

commit 1b151e2435fc3a9b10c8946c6aebe9f3e1938c55 upstream.

The special casing was originally added in pre-git history; reproducing
the commit log here:

> commit a318a92567d77
> Author: Andrew Morton 
> Date:   Sun Sep 21 01:42:22 2003 -0700
>
>     [PATCH] Speed up direct-io hugetlbpage handling
>
>     This patch short-circuits all the direct-io page dirtying logic for
>     higher-order pages.  Without this, we pointlessly bounce BIOs up to
>     keventd all the time.

In the last twenty years, compound pages have become used for more than
just hugetlb.  Rewrite these functions to operate on folios instead
of pages and remove the special case for hugetlbfs; I don't think
it's needed any more (and if it is, we can put it back in as a call
to folio_test_hugetlb()).

This was found by inspection; as far as I can tell, this bug can lead
to pages used as the destination of a direct I/O read not being marked
as dirty.  If those pages are then reclaimed by the MM without being
dirtied for some other reason, they won't be written out.  Then when
they're faulted back in, they will not contain the data they should.
It'll take a pretty unusual setup to produce this problem with several
races all going the wrong way.

This problem predates the folio work; it could for example have been
triggered by mmaping a THP in tmpfs and using that as the target of an
O_DIRECT read.

Fixes: 800d8c63b2e98 ("shmem: add huge pages support")
Cc:  
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!"

2023-12-20T14:41:20+00:00

[ Upstream commit 27b13e209ddca5979847a1b57890e0372c1edcee ]

Inside blkg_for_each_descendant_pre(), both
css_for_each_descendant_pre() and blkg_lookup() requires RCU read lock,
and either cgroup_assert_mutex_or_rcu_locked() or rcu_read_lock_held()
is called.

Fix the warning by adding rcu read lock.

Reported-by: Changhui Zhong 
Signed-off-by: Ming Lei 
Link: https://lore.kernel.org/r/20231117023527.3188627-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block/partition: fix signedness issue for Amiga partitions

2023-07-27T06:37:29+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

block: add overflow checks for Amiga partition support

2023-07-27T06:37:27+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

2023-07-27T06:37:19+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

block/blk-iocost (gcc13): keep large values in a new enum

2023-06-14T08:59:54+00:00

commit ff1cc97b1f4c10db224f276d9615b22835b8c424 upstream.

Since gcc13, each member of an enum has the same type as the enum [1]. And
that is inherited from its members. Provided:
  VTIME_PER_SEC_SHIFT     = 37,
  VTIME_PER_SEC           = 1LLU << VTIME_PER_SEC_SHIFT,
  ...
  AUTOP_CYCLE_NSEC        = 10LLU * NSEC_PER_SEC,
the named type is unsigned long.

This generates warnings with gcc-13:
  block/blk-iocost.c: In function 'ioc_weight_prfill':
  block/blk-iocost.c:3037:37: error: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'long unsigned int'

  block/blk-iocost.c: In function 'ioc_weight_show':
  block/blk-iocost.c:3047:34: error: format '%u' expects argument of type 'unsigned int', but argument 3 has type 'long unsigned int'

So split the anonymous enum with large values to a separate enum, so
that they don't affect other members.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36113

Cc: Martin Liska 
Cc: Tejun Heo 
Cc: Josef Bacik 
Cc: Jens Axboe 
Cc: cgroups@vger.kernel.org
Cc: linux-block@vger.kernel.org
Signed-off-by: Jiri Slaby (SUSE) 
Link: https://lore.kernel.org/r/20221213120826.17446-1-jirislaby@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-iocost: avoid 64-bit division in ioc_timer_fn

2023-06-14T08:59:54+00:00

commit 5f2779dfa7b8cc7dfd4a1b6586d86e0d193266f3 upstream.

The behavior of 'enum' types has changed in gcc-13, so now the
UNBUSY_THR_PCT constant is interpreted as a 64-bit number because
it is defined as part of the same enum definition as some other
constants that do not fit within a 32-bit integer. This in turn
leads to some inefficient code on 32-bit architectures as well
as a link error:

arm-linux-gnueabi/bin/arm-linux-gnueabi-ld: block/blk-iocost.o: in function `ioc_timer_fn':
blk-iocost.c:(.text+0x68e8): undefined reference to `__aeabi_uldivmod'
arm-linux-gnueabi-ld: blk-iocost.c:(.text+0x6908): undefined reference to `__aeabi_uldivmod'

Split the enum definition to keep the 64-bit timing constants in
a separate enum type from those constants that can clearly fit
within a smaller type.

Signed-off-by: Arnd Bergmann 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230118080706.3303186-1-arnd@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

treewide: Remove uninitialized_var() usage

2023-06-09T08:29:01+00:00

commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky  # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe  # IB
Acked-by: Kalle Valo  # wireless drivers
Reviewed-by: Chao Yu  # erofs
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman