commit a9ae6fe1c3 upstream.
The fallback code in blk_mq_map_hw_queues is original from
blk_mq_pci_map_queues and was added to handle the case where
pci_irq_get_affinity will return NULL for !SMP configuration.
blk_mq_map_hw_queues replaces besides blk_mq_pci_map_queues also
blk_mq_virtio_map_queues which used to use blk_mq_map_queues for the
fallback.
It's possible to use blk_mq_map_queues for both cases though.
blk_mq_map_queues creates the same map as blk_mq_clear_mq_map for !SMP
that is CPU 0 will be mapped to hctx 0.
The WARN_ON_ONCE has to be dropped for virtio as the fallback is also
taken for certain configuration on default. Though there is still a
WARN_ON_ONCE check in lib/group_cpus.c:
WARN_ON(nr_present + nr_others < numgrps);
which will trigger if the caller tries to create more hardware queues
than CPUs. It tests the same as the WARN_ON_ONCE in
blk_mq_pci_map_queues did.
Fixes: a5665c3d15 ("virtio: blk/scsi: replace blk_mq_virtio_map_queues with blk_mq_map_hw_queues")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Closes: https://lore.kernel.org/all/20250122093020.6e8a4e5b@gandalf.local.home/
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Link: https://lore.kernel.org/r/20250123-fix-blk_mq_map_hw_queues-v1-1-08dbd01f2c39@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7b720c7202 ]
When the user increased the read-ahead size through sysfs this value
currently get lost if the device is reprobe, including on a resume
from suspend.
As there is no hardware limitation for the read-ahead size there is
no real need to reset it or track a separate hardware limitation
like for max_sectors.
This restores the pre-atomic queue limit behavior in the sd driver as
sd did not use blk_queue_io_opt and thus never updated the read ahead
size to the value based of the optimal I/O, but changes behavior for
all other drivers. As the new behavior seems useful and sd is the
driver for which the readahead size tweaks are most useful that seems
like a worthwhile trade off.
Fixes: 804e498e04 ("sd: convert to the atomic queue limits API")
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20250424082521.1967286-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 39e1605051 upstream.
Placing multiple protection information buffers inside the same page
can lead to oopses because set_page_dirty_lock() can't be called from
interrupt context.
Since a protection information buffer is not backed by a file there is
no point in setting its page dirty, there is nothing to synchronize.
Drop the call to set_page_dirty_lock() and remove the last argument to
bio_integrity_unpin_bvec().
Cc: stable@vger.kernel.org
Fixes: 492c5d4559 ("block: bio-integrity: directly map user buffers")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/yq1v7r3ev9g.fsf@ca-mkp.ca.oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1452e9b470 ]
blk_mq_pci_map_queues and blk_mq_virtio_map_queues will create a CPU to
hardware queue mapping based on affinity information. These two function
share common code and only differ on how the affinity information is
retrieved. Also, those functions are located in the block subsystem
where it doesn't really fit in. They are virtio and pci subsystem
specific.
Thus introduce provide a generic mapping function which uses the
irq_get_affinity callback from bus_type.
Originally idea from Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Link: https://lore.kernel.org/r/20241202-refactor-blk-affinity-helpers-v6-4-27211e9c2cd5@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: a2d5a00722 ("scsi: smartpqi: Use is_kdump_kernel() to check for kdump")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e06472bab2 upstream.
The utf16_le_to_7bit function claims to, naively, convert a UTF-16
string to a 7-bit ASCII string. By naively, we mean that it:
* drops the first byte of every character in the original UTF-16 string
* checks if all characters are printable, and otherwise replaces them
by exclamation mark "!".
This means that theoretically, all characters outside the 7-bit ASCII
range should be replaced by another character. Examples:
* lower-case alpha (ɒ) 0x0252 becomes 0x52 (R)
* ligature OE (œ) 0x0153 becomes 0x53 (S)
* hangul letter pieup (ㅂ) 0x3142 becomes 0x42 (B)
* upper-case gamma (Ɣ) 0x0194 becomes 0x94 (not printable) so gets
replaced by "!"
The result of this conversion for the GPT partition name is passed to
user-space as PARTNAME via udev, which is confusing and feels questionable.
However, there is a flaw in the conversion function itself. By dropping
one byte of each character and using isprint() to check if the remaining
byte corresponds to a printable character, we do not actually guarantee
that the resulting character is 7-bit ASCII.
This happens because we pass 8-bit characters to isprint(), which
in the kernel returns 1 for many values > 0x7f - as defined in ctype.c.
This results in many values which should be replaced by "!" to be kept
as-is, despite not being valid 7-bit ASCII. Examples:
* e with acute accent (é) 0x00E9 becomes 0xE9 - kept as-is because
isprint(0xE9) returns 1.
* euro sign (€) 0x20AC becomes 0xAC - kept as-is because isprint(0xAC)
returns 1.
This way has broken pyudev utility[1], fixes it by using a mask of 7 bits
instead of 8 bits before calling isprint.
Link: https://github.com/pyudev/pyudev/issues/490#issuecomment-2685794648 [1]
Link: https://lore.kernel.org/linux-block/4cac90c2-e414-4ebb-ae62-2a4589d9dc6e@canonical.com/
Cc: Mulhern <amulhern@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: stable@vger.kernel.org
Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250305022154.3903128-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a6aa36e957 upstream.
For devices that natively support zone append operations,
REQ_OP_ZONE_APPEND BIOs are not processed through zone write plugging
and are immediately issued to the zoned device. This means that there is
no write pointer offset tracking done for these operations and that a
zone write plug is not necessary.
However, when receiving a zone append BIO, we may already have a zone
write plug for the target zone if that zone was previously partially
written using regular write operations. In such case, since the write
pointer offset of the zone write plug is not incremented by the amount
of sectors appended to the zone, 2 issues arise:
1) we risk leaving the plug in the disk hash table if the zone is fully
written using zone append or regular write operations, because the
write pointer offset will never reach the "zone full" state.
2) Regular write operations that are issued after zone append operations
will always be failed by blk_zone_wplug_prepare_bio() as the write
pointer alignment check will fail, even if the user correctly
accounted for the zone append operations and issued the regular
writes with a correct sector.
Avoid these issues by immediately removing the zone write plug of zones
that are the target of zone append operations when blk_zone_plug_bio()
is called. The new function blk_zone_wplug_handle_native_zone_append()
implements this for devices that natively support zone append. The
removal of the zone write plug using disk_remove_zone_wplug() requires
aborting all plugged regular write using disk_zone_wplug_abort() as
otherwise the plugged write BIOs would never be executed (with the plug
removed, the completion path will never see again the zone write plug as
disk_get_zone_wplug() will return NULL). Rate-limited warnings are added
to blk_zone_wplug_handle_native_zone_append() and to
disk_zone_wplug_abort() to signal this.
Since blk_zone_wplug_handle_native_zone_append() is called in the hot
path for operations that will not be plugged, disk_get_zone_wplug() is
optimized under the assumption that a user issuing zone append
operations is not at the same time issuing regular writes and that there
are no hashed zone write plugs. The struct gendisk atomic counter
nr_zone_wplugs is added to check this, with this counter incremented in
disk_insert_zone_wplug() and decremented in disk_remove_zone_wplug().
To be consistent with this fix, we do not need to fill the zone write
plug hash table with zone write plugs for zones that are partially
written for a device that supports native zone append operations.
So modify blk_revalidate_seq_zone() to return early to avoid allocating
and inserting a zone write plug for partially written sequential zones
if the device natively supports zone append.
Reported-by: Jorgen Hansen <Jorgen.Hansen@wdc.com>
Fixes: 9b1ce7f0c6 ("block: Implement zone append emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Jorgen Hansen <Jorgen.Hansen@wdc.com>
Link: https://lore.kernel.org/r/20250214041434.82564-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 80e648042e upstream.
Fix several issues in partition probing:
- The bailout for a bad partoffset must use put_dev_sector(), since the
preceding read_part_sector() succeeded.
- If the partition table claims a silly sector size like 0xfff bytes
(which results in partition table entries straddling sector boundaries),
bail out instead of accessing out-of-bounds memory.
- We must not assume that the partition table contains proper NUL
termination - use strnlen() and strncmp() instead of strlen() and
strcmp().
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20250214-partition-mac-v1-1-c1c626dffbd5@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b13ee668e8 upstream.
blkdev_read_iter() has a few odd checks, like gating the position and
count adjustment on whether or not the result is bigger-than-or-equal to
zero (where bigger than makes more sense), and not checking the return
value of blkdev_direct_IO() before doing an iov_iter_revert(). The
latter can lead to attempting to revert with a negative value, which
when passed to iov_iter_revert() as an unsigned value will lead to
throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT.
Be sane and don't revert for -EIOCBQUEUED, like what is done in other
spots.
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d432c817c2 ]
When __blk_mq_update_nr_hw_queues changes the number of tag sets, it
might have to disable poll queues. Currently it does so by adjusting
the BLK_FEAT_POLL, which is a bit against the intent of features that
describe hardware / driver capabilities, but more importantly causes
nasty lock order problems with the broadly held freeze when updating the
number of hardware queues and the limits lock. Fix this by leaving
BLK_FEAT_POLL alone, and instead check for the number of poll queues in
the bio submission and poll handlers. While this adds extra work to the
fast path, the variables are in cache lines used by these operations
anyway, so it should be cheap enough.
Fixes: 8023e144f9 ("block: move the poll flag to queue_limits")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250110054726.1499538-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 457ef47c08 ]
Set kernel config:
CONFIG_BLK_DEV_LOOP=m
CONFIG_BLK_DEV_LOOP_MIN_COUNT=0
Do latter:
mknod loop0 b 7 0
exec 4<> loop0
Before commit e418de3abc ("block: switch gendisk lookup to a simple
xarray"), lookup_gendisk will first use base_probe to load module loop,
and then the retry will call loop_probe to prepare the loop disk. Finally
open for this disk will success. However, after this commit, we lose the
retry logic, and open will fail with ENXIO. Block device autoloading is
deprecated and will be removed soon, but maybe we should keep open success
until we really remove it. So, give a retry to fix it.
Fixes: e418de3abc ("block: switch gendisk lookup to a simple xarray")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241209110435.3670985-1-yangerkun@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 031141976b ]
Copy back the bounce buffer to user-space in entirety when the parent
bio completes. The existing code uses bip_iter.bi_size for sizing the
copy, which can be modified. So move away from that and fetch it from
the vector passed to the block layer. While at it, switch to using
better variable names.
Fixes: 492c5d4559 ("block: bio-integrity: directly map user buffers")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20241128112240.8867-3-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 57e420c84f ]
After a recent change to clamp() and its variants [1] that increases the
coverage of the check that high is greater than low because it can be
done through inlining, certain build configurations (such as s390
defconfig) fail to build with clang with:
block/blk-iocost.c:1101:11: error: call to '__compiletime_assert_557' declared with 'error' attribute: clamp() low limit 1 greater than high limit active
1101 | inuse = clamp_t(u32, inuse, 1, active);
| ^
include/linux/minmax.h:218:36: note: expanded from macro 'clamp_t'
218 | #define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi)
| ^
include/linux/minmax.h:195:2: note: expanded from macro '__careful_clamp'
195 | __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_))
| ^
include/linux/minmax.h:188:2: note: expanded from macro '__clamp_once'
188 | BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \
| ^
__propagate_weights() is called with an active value of zero in
ioc_check_iocgs(), which results in the high value being less than the
low value, which is undefined because the value returned depends on the
order of the comparisons.
The purpose of this expression is to ensure inuse is not more than
active and at least 1. This could be written more simply with a ternary
expression that uses min(inuse, active) as the condition so that the
value of that condition can be used if it is not zero and one if it is.
Do this conversion to resolve the error and add a comment to deter
people from turning this back into clamp().
Fixes: 7caa47151a ("blkcg: implement blk-iocost")
Link: https://lore.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com/ [1]
Suggested-by: David Laight <david.laight@aculab.com>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/llvm/CA+G9fYsD7mw13wredcZn0L-KBA3yeoVSTuxnss-AEWMN3ha0cA@mail.gmail.com/
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412120322.3GfVe3vF-lkp@intel.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5eb3317aa5 upstream.
There are currently any issuer of REQ_OP_ZONE_RESET and
REQ_OP_ZONE_FINISH operations that set REQ_NOWAIT. However, as we cannot
handle this flag correctly due to the potential request allocation
failure that may happen in blk_mq_submit_bio() after blk_zone_plug_bio()
has handled the zone write plug write pointer updates for the targeted
zones, modify blk_zone_wplug_handle_reset_or_finish() to warn if this
flag is set and ignore it.
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241209122357.47838-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fe0418eb9b upstream.
Zone write plugging for handling writes to zones of a zoned block
device always execute a zone report whenever a write BIO to a zone
fails. The intent of this is to ensure that the tracking of a zone write
pointer is always correct to ensure that the alignment to a zone write
pointer of write BIOs can be checked on submission and that we can
always correctly emulate zone append operations using regular write
BIOs.
However, this error recovery scheme introduces a potential deadlock if a
device queue freeze is initiated while BIOs are still plugged in a zone
write plug and one of these write operation fails. In such case, the
disk zone write plug error recovery work is scheduled and executes a
report zone. This in turn can result in a request allocation in the
underlying driver to issue the report zones command to the device. But
with the device queue freeze already started, this allocation will
block, preventing the report zone execution and the continuation of the
processing of the plugged BIOs. As plugged BIOs hold a queue usage
reference, the queue freeze itself will never complete, resulting in a
deadlock.
Avoid this problem by completely removing from the zone write plugging
code the use of report zones operations after a failed write operation,
instead relying on the device user to either execute a report zones,
reset the zone, finish the zone, or give up writing to the device (which
is a fairly common pattern for file systems which degrade to read-only
after write failures). This is not an unreasonnable requirement as all
well-behaved applications, FSes and device mapper already use report
zones to recover from write errors whenever possible by comparing the
current position of a zone write pointer with what their assumption
about the position is.
The changes to remove the automatic error recovery are as follows:
- Completely remove the error recovery work and its associated
resources (zone write plug list head, disk error list, and disk
zone_wplugs_work work struct). This also removes the functions
disk_zone_wplug_set_error() and disk_zone_wplug_clear_error().
- Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into
BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write
plug whenever a write opration targetting the zone of the zone write
plug fails. This flag indicates that the zone write pointer offset is
not reliable and that it must be updated when the next report zone,
reset zone, finish zone or disk revalidation is executed.
- Modify blk_zone_write_plug_bio_endio() to set the
BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed
write BIO.
- Modify the function disk_zone_wplug_set_wp_offset() to clear this
new flag, thus implementing recovery of a correct write pointer
offset with the reset (all) zone and finish zone operations.
- Modify blkdev_report_zones() to always use the disk_report_zones_cb()
callback so that disk_zone_wplug_sync_wp_offset() can be called for
any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag.
This implements recovery of a correct write pointer offset for zone
write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within
the range of the report zones operation executed by the user.
- Modify blk_revalidate_seq_zone() to call
disk_zone_wplug_sync_wp_offset() for all sequential write required
zones when a zoned block device is revalidated, thus always resolving
any inconsistency between the write pointer offset of zone write
plugs and the actual write pointer position of sequential zones.
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241209122357.47838-5-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b76b840fd9 upstream.
The zone reclaim processing of the dm-zoned device mapper uses
blkdev_issue_zeroout() to align the write pointer of a zone being used
for reclaiming another zone, to write the valid data blocks from the
zone being reclaimed at the same position relative to the zone start in
the reclaim target zone.
The first call to blkdev_issue_zeroout() will try to use hardware
offload using a REQ_OP_WRITE_ZEROES operation if the device reports a
non-zero max_write_zeroes_sectors queue limit. If this operation fails
because of the lack of hardware support, blkdev_issue_zeroout() falls
back to using a regular write operation with the zero-page as buffer.
Currently, such REQ_OP_WRITE_ZEROES failure is automatically handled by
the block layer zone write plugging code which will execute a report
zones operation to ensure that the write pointer of the target zone of
the failed operation has not changed and to "rewind" the zone write
pointer offset of the target zone as it was advanced when the write zero
operation was submitted. So the REQ_OP_WRITE_ZEROES failure does not
cause any issue and blkdev_issue_zeroout() works as expected.
However, since the automatic recovery of zone write pointers by the zone
write plugging code can potentially cause deadlocks with queue freeze
operations, a different recovery must be implemented in preparation for
the removal of zone write plugging report zones based recovery.
Do this by introducing the new function blk_zone_issue_zeroout(). This
function first calls blkdev_issue_zeroout() with the flag
BLKDEV_ZERO_NOFALLBACK to intercept failures on the first execution
which attempt to use the device hardware offload with the
REQ_OP_WRITE_ZEROES operation. If this attempt fails, a report zone
operation is issued to restore the zone write pointer offset of the
target zone to the correct position and blkdev_issue_zeroout() is called
again without the BLKDEV_ZERO_NOFALLBACK flag. The report zones
operation performing this recovery is implemented using the helper
function disk_zone_sync_wp_offset() which calls the gendisk report_zones
file operation with the callback disk_report_zones_cb(). This callback
updates the target write pointer offset of the target zone using the new
function disk_zone_wplug_sync_wp_offset().
dmz_reclaim_align_wp() is modified to change its call to
blkdev_issue_zeroout() to a call to blk_zone_issue_zeroout() without any
other change needed as the two functions are functionnally equivalent.
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241209122357.47838-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cae0056708 upstream.
For zoned block devices, a write BIO issued to a zone that has no
on-going writes will be prepared for execution and allowed to execute
immediately by blk_zone_wplug_handle_write() (called from
blk_zone_plug_bio()). However, if this BIO specifies REQ_NOWAIT, the
allocation of a request for its execution in blk_mq_submit_bio() may
fail after blk_zone_plug_bio() completed, marking the target zone of the
BIO as plugged. When this BIO is retried later on, it will be blocked as
the zone write plug of the target zone is in a plugged state without any
on-going write operation (completion of write operations trigger
unplugging of the next write BIOs for a zone). This leads to a BIO that
is stuck in a zone write plug and never completes, which results in
various issues such as hung tasks.
Avoid this problem by always executing REQ_NOWAIT write BIOs using the
BIO work of a zone write plug. This ensure that we never block the BIO
issuer and can thus safely ignore the REQ_NOWAIT flag when executing the
BIO from the zone write plug BIO work.
Since such BIO may be the first write BIO issued to a zone with no
on-going write, modify disk_zone_wplug_add_bio() to schedule the zone
write plug BIO work if the write plug is not already marked with the
BLK_ZONE_WPLUG_PLUGGED flag. This scheduling is otherwise not necessary
as the completion of the on-going write for the zone will schedule the
execution of the next plugged BIOs.
blk_zone_wplug_handle_write() is also fixed to better handle zone write
plug allocation failures for REQ_NOWAIT BIOs by failing a write BIO
using bio_wouldblock_error() instead of bio_io_error().
Reported-by: Bart Van Assche <bvanassche@acm.org>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241209122357.47838-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 86e6ca55b8 upstream.
blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To
walk up, it uses blkcg_parent(blkcg) but it was calling that after
blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the
following UAF:
==================================================================
BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270
Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117
CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
dump_stack_lvl+0x27/0x80
print_report+0x151/0x710
kasan_report+0xc0/0x100
blkcg_unpin_online+0x15a/0x270
cgwb_release_workfn+0x194/0x480
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
...
Freed by task 1944:
kasan_save_track+0x2b/0x70
kasan_save_free_info+0x3c/0x50
__kasan_slab_free+0x33/0x50
kfree+0x10c/0x330
css_free_rwork_fn+0xe6/0xb30
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
Note that the UAF is not easy to trigger as the free path is indirected
behind a couple RCU grace periods and a work item execution. I could only
trigger it with artifical msleep() injected in blkcg_unpin_online().
Fix it by reading the parent pointer before destroying the blkcg's blkg's.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Abagail ren <renzezhongucas@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 4308a434e5 ("blkcg: don't offline parent blkcg first")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d7cb6d7414 ]
Ensure that a disk revalidation changing the conventional zones bitmap
of a disk does not cause invalid memory references when using the
disk_zone_is_conv() helper by RCU protecting the disk->conv_zones_bitmap
pointer.
disk_zone_is_conv() is modified to operate under the RCU read lock and
the function disk_set_conv_zones_bitmap() is added to update a disk
conv_zones_bitmap pointer using rcu_replace_pointer() with the disk
zone_wplugs_lock spinlock held.
disk_free_zone_resources() is modified to call
disk_update_zone_resources() with a NULL bitmap pointer to free the disk
conv_zones_bitmap. disk_set_conv_zones_bitmap() is also used in
disk_update_zone_resources() to set the new (revalidated) bitmap and
free the old one.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20241107064300.227731-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6a78699838 upstream.
commit f1be1788a3 ("block: model freeze & enter queue as lock for
supporting lockdep") tries to apply lockdep for verifying freeze &
unfreeze. However, the verification is only done the outmost freeze and
unfreeze. This way is actually not correct because q->mq_freeze_depth
still may drop to zero on other task instead of the freeze owner task.
Fix this issue by always verifying the last unfreeze lock on the owner
task context, and make sure both the outmost freeze & unfreeze are
verified in the current task.
Fixes: f1be1788a3 ("block: model freeze & enter queue as lock for supporting lockdep")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241031133723.303835-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e8b8344de3 ]
Set new allocated bfqq to bic or remove freed bfqq from bic are both
protected by bfqd->lock, however bfq_limit_depth() is deferencing bfqq
from bic without the lock, this can lead to UAF if the io_context is
shared by multiple tasks.
For example, test bfq with io_uring can trigger following UAF in v6.6:
==================================================================
BUG: KASAN: slab-use-after-free in bfqq_group+0x15/0x50
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x80
print_address_description.constprop.0+0x66/0x300
print_report+0x3e/0x70
kasan_report+0xb4/0xf0
bfqq_group+0x15/0x50
bfqq_request_over_limit+0x130/0x9a0
bfq_limit_depth+0x1b5/0x480
__blk_mq_alloc_requests+0x2b5/0xa00
blk_mq_get_new_requests+0x11d/0x1d0
blk_mq_submit_bio+0x286/0xb00
submit_bio_noacct_nocheck+0x331/0x400
__block_write_full_folio+0x3d0/0x640
writepage_cb+0x3b/0xc0
write_cache_pages+0x254/0x6c0
write_cache_pages+0x254/0x6c0
do_writepages+0x192/0x310
filemap_fdatawrite_wbc+0x95/0xc0
__filemap_fdatawrite_range+0x99/0xd0
filemap_write_and_wait_range.part.0+0x4d/0xa0
blkdev_read_iter+0xef/0x1e0
io_read+0x1b6/0x8a0
io_issue_sqe+0x87/0x300
io_wq_submit_work+0xeb/0x390
io_worker_handle_work+0x24d/0x550
io_wq_worker+0x27f/0x6c0
ret_from_fork_asm+0x1b/0x30
</TASK>
Allocated by task 808602:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_slab_alloc+0x83/0x90
kmem_cache_alloc_node+0x1b1/0x6d0
bfq_get_queue+0x138/0xfa0
bfq_get_bfqq_handle_split+0xe3/0x2c0
bfq_init_rq+0x196/0xbb0
bfq_insert_request.isra.0+0xb5/0x480
bfq_insert_requests+0x156/0x180
blk_mq_insert_request+0x15d/0x440
blk_mq_submit_bio+0x8a4/0xb00
submit_bio_noacct_nocheck+0x331/0x400
__blkdev_direct_IO_async+0x2dd/0x330
blkdev_write_iter+0x39a/0x450
io_write+0x22a/0x840
io_issue_sqe+0x87/0x300
io_wq_submit_work+0xeb/0x390
io_worker_handle_work+0x24d/0x550
io_wq_worker+0x27f/0x6c0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x1b/0x30
Freed by task 808589:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x27/0x40
__kasan_slab_free+0x126/0x1b0
kmem_cache_free+0x10c/0x750
bfq_put_queue+0x2dd/0x770
__bfq_insert_request.isra.0+0x155/0x7a0
bfq_insert_request.isra.0+0x122/0x480
bfq_insert_requests+0x156/0x180
blk_mq_dispatch_plug_list+0x528/0x7e0
blk_mq_flush_plug_list.part.0+0xe5/0x590
__blk_flush_plug+0x3b/0x90
blk_finish_plug+0x40/0x60
do_writepages+0x19d/0x310
filemap_fdatawrite_wbc+0x95/0xc0
__filemap_fdatawrite_range+0x99/0xd0
filemap_write_and_wait_range.part.0+0x4d/0xa0
blkdev_read_iter+0xef/0x1e0
io_read+0x1b6/0x8a0
io_issue_sqe+0x87/0x300
io_wq_submit_work+0xeb/0x390
io_worker_handle_work+0x24d/0x550
io_wq_worker+0x27f/0x6c0
ret_from_fork+0x2d/0x50
ret_from_fork_asm+0x1b/0x30
Fix the problem by protecting bic_to_bfqq() with bfqd->lock.
CC: Jan Kara <jack@suse.cz>
Fixes: 76f1df88bb ("bfq: Limit number of requests consumed by each cgroup")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241129091509.2227136-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f1be1788a3 ]
Recently we got several deadlock report[1][2][3] caused by
blk_mq_freeze_queue and blk_enter_queue().
Turns out the two are just like acquiring read/write lock, so model them
as read/write lock for supporting lockdep:
1) model q->q_usage_counter as two locks(io and queue lock)
- queue lock covers sync with blk_enter_queue()
- io lock covers sync with bio_enter_queue()
2) make the lockdep class/key as per-queue:
- different subsystem has very different lock use pattern, shared lock
class causes false positive easily
- freeze_queue degrades to no lock in case that disk state becomes DEAD
because bio_enter_queue() won't be blocked any more
- freeze_queue degrades to no lock in case that request queue becomes dying
because blk_enter_queue() won't be blocked any more
3) model blk_mq_freeze_queue() as acquire_exclusive & try_lock
- it is exclusive lock, so dependency with blk_enter_queue() is covered
- it is trylock because blk_mq_freeze_queue() are allowed to run
concurrently
4) model blk_enter_queue() & bio_enter_queue() as acquire_read()
- nested blk_enter_queue() are allowed
- dependency with blk_mq_freeze_queue() is covered
- blk_queue_exit() is often called from other contexts(such as irq), and
it can't be annotated as lock_release(), so simply do it in
blk_enter_queue(), this way still covered cases as many as possible
With lockdep support, such kind of reports may be reported asap and
needn't wait until the real deadlock is triggered.
For example, lockdep report can be triggered in the report[3] with this
patch applied.
[1] occasional block layer hang when setting 'echo noop > /sys/block/sda/queue/scheduler'
https://bugzilla.kernel.org/show_bug.cgi?id=219166
[2] del_gendisk() vs blk_queue_enter() race condition
https://lore.kernel.org/linux-block/20241003085610.GK11458@google.com/
[3] queue_freeze & queue_enter deadlock in scsi
https://lore.kernel.org/linux-block/ZxG38G9BuFdBpBHZ@fedora/T/#u
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241025003722.3630252-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 3802f73bd8 ("block: fix uaf for flush rq while iterating tags")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8acdd0e7bf ]
Add non_owner variant of start_freeze/unfreeze queue APIs, so that the
caller knows that what they are doing, and we can skip lockdep support
for non_owner variant in per-call level.
Prepare for supporting lockdep for freezing/unfreezing queue.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241025003722.3630252-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 3802f73bd8 ("block: fix uaf for flush rq while iterating tags")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 96a9fe64bf upstream.
Supposing first scenario with a virtio_blk driver.
CPU0 CPU1
blk_mq_try_issue_directly()
__blk_mq_issue_directly()
q->mq_ops->queue_rq()
virtio_queue_rq()
blk_mq_stop_hw_queue()
virtblk_done()
blk_mq_request_bypass_insert() 1) store
blk_mq_start_stopped_hw_queue()
clear_bit(BLK_MQ_S_STOPPED) 3) store
blk_mq_run_hw_queue()
if (!blk_mq_hctx_has_pending()) 4) load
return
blk_mq_sched_dispatch_requests()
blk_mq_run_hw_queue()
if (!blk_mq_hctx_has_pending())
return
blk_mq_sched_dispatch_requests()
if (blk_mq_hctx_stopped()) 2) load
return
__blk_mq_sched_dispatch_requests()
Supposing another scenario.
CPU0 CPU1
blk_mq_requeue_work()
blk_mq_insert_request() 1) store
virtblk_done()
blk_mq_start_stopped_hw_queue()
blk_mq_run_hw_queues() clear_bit(BLK_MQ_S_STOPPED) 3) store
blk_mq_run_hw_queue()
if (!blk_mq_hctx_has_pending()) 4) load
return
blk_mq_sched_dispatch_requests()
if (blk_mq_hctx_stopped()) 2) load
continue
blk_mq_run_hw_queue()
Both scenarios are similar, the full memory barrier should be inserted
between 1) and 2), as well as between 3) and 4) to make sure that either
CPU0 sees BLK_MQ_S_STOPPED is cleared or CPU1 sees dispatch list.
Otherwise, either CPU will not rerun the hardware queue causing
starvation of the request.
The easy way to fix it is to add the essential full memory barrier into
helper of blk_mq_hctx_stopped(). In order to not affect the fast path
(hardware queue is not stopped most of the time), we only insert the
barrier into the slow path. Actually, only slow path needs to care about
missing of dispatching the request to the low-level device driver.
Fixes: 320ae51fee ("blk-mq: new multi-queue block IO queueing mechanism")
Cc: stable@vger.kernel.org
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241014092934.53630-4-songmuchun@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6bda857bcb upstream.
Supposing the following scenario.
CPU0 CPU1
blk_mq_insert_request() 1) store
blk_mq_unquiesce_queue()
blk_queue_flag_clear() 3) store
blk_mq_run_hw_queues()
blk_mq_run_hw_queue()
if (!blk_mq_hctx_has_pending()) 4) load
return
blk_mq_run_hw_queue()
if (blk_queue_quiesced()) 2) load
return
blk_mq_sched_dispatch_requests()
The full memory barrier should be inserted between 1) and 2), as well as
between 3) and 4) to make sure that either CPU0 sees QUEUE_FLAG_QUIESCED
is cleared or CPU1 sees dispatch list or setting of bitmap of software
queue. Otherwise, either CPU will not rerun the hardware queue causing
starvation.
So the first solution is to 1) add a pair of memory barrier to fix the
problem, another solution is to 2) use hctx->queue->queue_lock to
synchronize QUEUE_FLAG_QUIESCED. Here, we chose 2) to fix it since
memory barrier is not easy to be maintained.
Fixes: f4560ffe8c ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue")
Cc: stable@vger.kernel.org
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241014092934.53630-3-songmuchun@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2003ee8a9a upstream.
Supposing the following scenario with a virtio_blk driver.
CPU0 CPU1 CPU2
blk_mq_try_issue_directly()
__blk_mq_issue_directly()
q->mq_ops->queue_rq()
virtio_queue_rq()
blk_mq_stop_hw_queue()
virtblk_done()
blk_mq_try_issue_directly()
if (blk_mq_hctx_stopped())
blk_mq_request_bypass_insert() blk_mq_run_hw_queue()
blk_mq_run_hw_queue() blk_mq_run_hw_queue()
blk_mq_insert_request()
return
After CPU0 has marked the queue as stopped, CPU1 will see the queue is
stopped. But before CPU1 puts the request on the dispatch list, CPU2
receives the interrupt of completion of request, so it will run the
hardware queue and marks the queue as non-stopped. Meanwhile, CPU1 also
runs the same hardware queue. After both CPU1 and CPU2 complete
blk_mq_run_hw_queue(), CPU1 just puts the request to the same hardware
queue and returns. It misses dispatching a request. Fix it by running
the hardware queue explicitly. And blk_mq_request_issue_directly()
should handle a similar situation. Fix it as well.
Fixes: d964f04a8f ("blk-mq: fix direct issue")
Cc: stable@vger.kernel.org
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241014092934.53630-2-songmuchun@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Daniel Wagner
Christoph Hellwig
Ming Lei
Martin K. Petersen
Zheng Qixing
Olivier Gayot
Damien Le Moal
Jann Horn
Jens Axboe
Zijun Hu
Randy Dunlap
Yang Erkun
Yu Kuai
Nilay Shroff
Nathan Chancellor
LongPing Wei
Tejun Heo
John Garry
Bart Van Assche
Muchun Song