linux-stable.git/block, branch v6.6.27

block: prevent division by zero in blk_rq_stat_sum()

2024-04-13T11:07:37+00:00

[ Upstream commit 93f52fbeaf4b676b21acfe42a5152620e6770d02 ]

The expression dst->nr_samples + src->nr_samples may
have zero value on overflow. It is necessary to add
a check to avoid division by zero.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Signed-off-by: Roman Smirnov 
Reviewed-by: Sergey Shtylyov 
Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Do not force full zone append completion in req_bio_endio()

2024-04-03T13:28:56+00:00

commit 55251fbdf0146c252ceff146a1bb145546f3e034 upstream.

This reverts commit 748dc0b65ec2b4b7b3dbd7befcc4a54fdcac7988.

Partial zone append completions cannot be supported as there is no
guarantees that the fragmented data will be written sequentially in the
same manner as with a full command. Commit 748dc0b65ec2 ("block: fix
partial zone append completion handling in req_bio_endio()") changed
req_bio_endio() to always advance a partially failed BIO by its full
length, but this can lead to incorrect accounting. So revert this
change and let low level device drivers handle this case by always
failing completely zone append operations. With this revert, users will
still see an IO error for a partially completed zone append BIO.

Fixes: 748dc0b65ec2 ("block: fix partial zone append completion handling in req_bio_endio()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20240328004409.594888-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

Revert "block/mq-deadline: use correct way to throttling write requests"

2024-04-03T13:28:33+00:00

[ Upstream commit 256aab46e31683d76d45ccbedc287b4d3f3e322b ]

The code "max(1U, 3 * (1U << shift)  / 4)" comes from the Kyber I/O
scheduler. The Kyber I/O scheduler maintains one internal queue per hwq
and hence derives its async_depth from the number of hwq tags. Using
this approach for the mq-deadline scheduler is wrong since the
mq-deadline scheduler maintains one internal queue for all hwqs
combined. Hence this revert.

Cc: stable@vger.kernel.org
Cc: Damien Le Moal 
Cc: Harshit Mogalapalli 
Cc: Zhiguo Niu 
Fixes: d47f9717e5cf ("block/mq-deadline: use correct way to throttling write requests")
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20240313214218.1736147-1-bvanassche@acm.org
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Fix page refcounts for unaligned buffers in __bio_release_pages()

2024-04-03T13:28:27+00:00

[ Upstream commit 38b43539d64b2fa020b3b9a752a986769f87f7a6 ]

Fix an incorrect number of pages being released for buffers that do not
start at the beginning of a page.

Fixes: 1b151e2435fc ("block: Remove special-casing of compound pages")
Cc: stable@vger.kernel.org
Signed-off-by: Tony Battersby 
Tested-by: Greg Edwards 
Link: https://lore.kernel.org/r/86e592a9-98d4-4cff-a646-0c0084328356@cybernetics.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Clear zone limits for a non-zoned stacked queue

2024-04-03T13:28:20+00:00

[ Upstream commit c8f6f88d25929ad2f290b428efcae3b526f3eab0 ]

Device mapper may create a non-zoned mapped device out of a zoned device
(e.g., the dm-zoned target). In such case, some queue limit such as the
max_zone_append_sectors and zone_write_granularity endup being non zero
values for a block device that is not zoned. Avoid this by clearing
these limits in blk_stack_limits() when the stacked zoned limit is
false.

Fixes: 3093a479727b ("block: inherit the zoned characteristics in blk_stack_limits")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Link: https://lore.kernel.org/r/20240222131724.1803520-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Provide bdev_open_* functions

2024-03-26T22:19:40+00:00

[ Upstream commit e719b4d156749f02eafed31a3c515f2aa9dcc72a ]

Create struct bdev_handle that contains all parameters that need to be
passed to blkdev_put() and provide bdev_open_* functions that return
this structure instead of plain bdev pointer. This will eventually allow
us to pass one more argument to blkdev_put() (renamed to bdev_release())
without too much hassle.

Acked-by: Christoph Hellwig 
Reviewed-by: Christian Brauner 
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20230927093442.25915-1-jack@suse.cz
Signed-off-by: Christian Brauner 
Stable-dep-of: 0f28be64d132 ("erofs: fix lockdep false positives on initializing erofs_pseudo_mnt")
Signed-off-by: Sasha Levin

block: sed-opal: handle empty atoms when parsing response

2024-03-26T22:19:12+00:00

[ Upstream commit 5429c8de56f6b2bd8f537df3a1e04e67b9c04282 ]

The SED Opal response parsing function response_parse() does not
handle the case of an empty atom in the response. This causes
the entry count to be too high and the response fails to be
parsed. Recognizing, but ignoring, empty atoms allows response
handling to succeed.

Signed-off-by: Greg Joyce 
Link: https://lore.kernel.org/r/20240216210417.3526064-2-gjoyce@linux.ibm.com
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: Fix WARNING in _copy_from_iter

2024-03-01T12:34:49+00:00

[ Upstream commit 13f3956eb5681a4045a8dfdef48df5dc4d9f58a6 ]

Syzkaller reports a warning in _copy_from_iter because an
iov_iter is supposedly used in the wrong direction. The reason
is that syzcaller managed to generate a request with
a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs
the kernel to copy user buffers into the kernel, read into
the copied buffers and then copy the data back to user space.

Thus the iovec is used in both directions.

Detect this situation in the block layer and construct a new
iterator with the correct direction for the copy-in.

Reported-by: syzbot+a532b03fdfee2c137666@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000009b92c10604d7a5e9@google.com/t/
Reported-by: syzbot+63dec323ac56c28e644f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/0000000000003faaa105f6e7c658@google.com/T/
Signed-off-by: Christian A. Ehrhardt 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20240121202634.275068-1-lk@c--e.de
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: fix partial zone append completion handling in req_bio_endio()

2024-02-23T08:25:18+00:00

[ Upstream commit 748dc0b65ec2b4b7b3dbd7befcc4a54fdcac7988 ]

Partial completions of zone append request is not allowed but if a zone
append completion indicates a number of completed bytes different from
the original BIO size, only the BIO status is set to error. This leads
to bio_advance() not setting the BIO size to 0 and thus to not call
bio_endio() at the end of req_bio_endio().

Make sure a partially completed zone append is failed and completed
immediately by forcing the completed number of bytes (nbytes) to be
equal to the BIO size, thus ensuring that bio_endio() is called.

Fixes: 297db731847e ("block: fix req_bio_endio append error handling")
Cc: stable@kernel.vger.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20240110092942.442334-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

blk-wbt: Fix detection of dirty-throttled tasks

2024-02-23T08:25:16+00:00

commit f814bdda774c183b0cc15ec8f3b6e7c6f4527ba5 upstream.

The detection of dirty-throttled tasks in blk-wbt has been subtly broken
since its beginning in 2016. Namely if we are doing cgroup writeback and
the throttled task is not in the root cgroup, balance_dirty_pages() will
set dirty_sleep for the non-root bdi_writeback structure. However
blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback
structure. Thus detection of recently throttled tasks is not working in
this case (we noticed this when we switched to cgroup v2 and suddently
writeback was slow).

Since blk-wbt has no easy way to get to proper bdi_writeback and
furthermore its intention has always been to work on the whole device
rather than on individual cgroups, just move the dirty_sleep timestamp
from bdi_writeback to backing_dev_info. That fixes the checking for
recently throttled task and saves memory for everybody as a bonus.

CC: stable@vger.kernel.org
Fixes: b57d74aff9ab ("writeback: track if we're sleeping on progress in balance_dirty_pages()")
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20240123175826.21452-1-jack@suse.cz
[axboe: fixup indentation errors]
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman