If we fail to read a logical block size in virtblk_read_limits() ->
virtio_cread_feature(), then we default to what is in
lim->logical_block_size, but that would be 0.
We can deal with lim->logical_block_size = 0 later in the
blk_mq_alloc_disk(), but the code in virtblk_read_limits() needs a proper
default, so give a default of SECTOR_SIZE.
Fixes: 27e32cd23f ("block: pass a queue_limits argument to blk_mq_alloc_disk")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240708091651.177447-2-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ensure that info->sector_size and info->physical_sector_size are set
before the call to blkif_set_queue_limits by doing away with the
local variables and arguments that propagate them.
Thanks to Marek Marczykowski-Górecki and Jürgen Groß for root causing
the issue.
Fixes: ba3f67c116 ("xen-blkfront: atomically update queue limits")
Reported-by: Rusty Bird <rustybird@net-c.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20240625055238.7934-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
QUEUE_FLAG_NOMERGES isn't really a driver interface, but a user tunable.
There also isn't any good reason to set it in the loop driver.
The original commit adding it (5b5e20f421 "block: loop: set
QUEUE_FLAG_NOMERGES for request queue of loop") claims that "It doesn't
make sense to enable merge because the I/O submitted to backing file is
handled page by page." which of course isn't true for multi-page bvec
now, and it never has been for direct I/O, for which commit 40326d8a33
("block/loop: allow request merge for directio mode") alredy disabled
the nomerges flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240627124926.512662-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1. Userspace sends the command "losetup -d" which uses the open() call
to open the device
2. Kernel receives the ioctl command "LOOP_CLR_FD" which calls the
function loop_clr_fd()
3. If LOOP_CLR_FD is the first command received at the time, then the
AUTOCLEAR flag is not set and deletion of the
loop device proceeds ahead and scans the partitions (drop/add
partitions)
if (disk_openers(lo->lo_disk) > 1) {
lo->lo_flags |= LO_FLAGS_AUTOCLEAR;
loop_global_unlock(lo, true);
return 0;
}
4. Before scanning partitions, it will check to see if any partition of
the loop device is currently opened
5. If any partition is opened, then it will return EBUSY:
if (disk->open_partitions)
return -EBUSY;
6. So, after receiving the "LOOP_CLR_FD" command and just before the above
check for open_partitions, if any other command
(like blkid) opens any partition of the loop device, then the partition
scan will not proceed and EBUSY is returned as shown in above code
7. But in "__loop_clr_fd()", this EBUSY error is not propagated
8. We have noticed that this is causing the partitions of the loop to
remain stale even after the loop device is detached resulting in the
IO errors on the partitions
Fix:
Defer the detach of loop device to release function, which is called when
the last close happens, by setting the lo_flags to LO_FLAGS_AUTOCLEAR at
the time of detach i.e in loop_clr_fd() function.
Test case involves the following two scripts:
script1.sh:
while [ 1 ];
do
losetup -P -f /home/opt/looptest/test10.img
blkid /dev/loop0p1
done
script2.sh:
while [ 1 ];
do
losetup -d /dev/loop0
done
Without fix, the following IO errors have been observed:
kernel: __loop_clr_fd: partition scan of loop0 failed (rc=-16)
kernel: I/O error, dev loop0, sector 20971392 op 0x0:(READ) flags 0x80700
phys_seg 1 prio class 0
kernel: I/O error, dev loop0, sector 108868 op 0x0:(READ) flags 0x0
phys_seg 1 prio class 0
kernel: Buffer I/O error on dev loop0p1, logical block 27201, async page
read
Signed-off-by: Gulam Mohamed <gulam.mohamed@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240618164042.343777-1-gulam.mohamed@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in last round of queue limits changes from Christoph.
* for-6.11/block-limits: (26 commits)
block: move the bounce flag into the features field
block: move the skip_tagset_quiesce flag to queue_limits
block: move the pci_p2pdma flag to queue_limits
block: move the zone_resetall flag to queue_limits
block: move the zoned flag into the features field
block: move the poll flag to queue_limits
block: move the dax flag to queue_limits
block: move the nowait flag to queue_limits
block: move the synchronous flag to queue_limits
block: move the stable_writes flag to queue_limits
block: move the io_stat flag setting to queue_limits
block: move the add_random flag to queue_limits
block: move the nonrot flag to queue_limits
block: move cache control settings out of queue->flags
block: remove blk_flush_policy
block: freeze the queue in queue_attr_store
nbd: move setting the cache control flags to __nbd_set_size
virtio_blk: remove virtblk_update_cache_mode
loop: fold loop_update_rotational into loop_reconfigure_limits
loop: also use the default block size from an underlying block device
...
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the nowait flag into the queue_limits feature field so that it can
be set atomically with the queue frozen.
Stacking drivers are simplified in that they now can simply set the
flag, and blk_stack_limits will clear it when the features is not
supported by any of the underlying devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the stable_writes flag into the queue_limits feature field so that
it can be set atomically with the queue frozen.
The flag is now inherited by blk_stack_limits, which greatly simplifies
the code in dm, and fixed md which previously did not pass on the flag
set on lower devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the add_random flag into the queue_limits feature field so that it
can be set atomically with the queue frozen.
Note that this also removes code from dm to clear the flag based on
the underlying devices, which can't be reached as dm devices will
always start out without the flag set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the nonrot flag into the queue_limits feature field so that it can
be set atomically with the queue frozen.
Use the chance to switch to defaulting to non-rotational and require
the driver to opt into rotational, which matches the polarity of the
sysfs interface.
For the z2ram, ps3vram, 2x memstick, ubiblock and dcssblk the new
rotational flag is not set as they clearly are not rotational despite
this being a behavior change. There are some other drivers that
unconditionally set the rotational flag to keep the existing behavior
as they arguably can be used on rotational devices even if that is
probably not their main use today (e.g. virtio_blk and drbd).
The flag is automatically inherited in blk_stack_limits matching the
existing behavior in dm and md.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the cache control settings into the queue_limits so that the flags
can be set atomically with the device queue frozen.
Add new features and flags field for the driver set flags, and internal
(usually sysfs-controlled) flags in the block layer. Note that we'll
eventually remove enough field from queue_limits to bring it back to the
previous size.
The disable flag is inverted compared to the previous meaning, which
means it now survives a rescan, similar to the max_sectors and
max_discard_sectors user limits.
The FLUSH and FUA flags are now inherited by blk_stack_limits, which
simplified the code in dm a lot, but also causes a slight behavior
change in that dm-switch and dm-unstripe now advertise a write cache
despite setting num_flush_bios to 0. The I/O path will handle this
gracefully, but as far as I can tell the lack of num_flush_bios
and thus flush support is a pre-existing data integrity bug in those
targets that really needs fixing, after which a non-zero num_flush_bios
should be required in dm for targets that map to underlying devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The LOOP_CONFIGURE path automatically upgrades the block size to that
of the underlying file for O_DIRECT file descriptors, but the
LOOP_SET_BLOCK_SIZE path does not. Fix this by lifting the code to
pick the block size into common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240617060532.127975-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkfront always had a robust negotiation protocol for detecting a write
cache. Stop simply disabling cache flushes in the block layer as the
flags handling is moving to the atomic queue limits API that needs
user context to freeze the queue for that. Instead handle the case
of the feature flags cleared inside of blkfront. This removes old
debug code to check for such a mismatch which was previously impossible
to hit, including the check for passthrough requests that blkfront
never used to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull in block limits branch, which exists as a shared branch for both
the block and SCSI tree.
* for-6.11/block-limits: (26 commits)
block: move integrity information into queue_limits
block: invert the BLK_INTEGRITY_{GENERATE,VERIFY} flags
block: bypass the STABLE_WRITES flag for protection information
block: don't require stable pages for non-PI metadata
block: use kstrtoul in flag_store
block: factor out flag_{store,show} helper for integrity
block: remove the blk_flush_integrity call in blk_integrity_unregister
block: remove the blk_integrity_profile structure
dm-integrity: use the nop integrity profile
md/raid1: don't free conf on raid0_run failure
md/raid0: don't free conf on raid0_run failure
block: initialize integrity buffer to zero before writing it to media
block: add special APIs for run-time disabling of discard and friends
block: remove unused queue limits API
sr: convert to the atomic queue limits API
sd: convert to the atomic queue limits API
sd: cleanup zoned queue limits initialization
sd: factor out a sd_discard_mode helper
sd: simplify the disable case in sd_config_discard
sd: add a sd_disable_write_same helper
...
A few drivers optimistically try to support discard, write zeroes and
secure erase and disable the features from the I/O completion handler
if the hardware can't support them. This disable can't be done using
the atomic queue limits API because the I/O completion handlers can't
take sleeping locks or freeze the queue. Keep the existing clearing
of the relevant field to zero, but replace the old blk_queue_max_*
APIs with new disable APIs that force the value to 0.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The soft max_sectors limit is normally capped by the hardware limits and
an arbitrary upper limit enforced by the kernel, but can be modified by
the user. A few drivers want to increase this limit (nbd, rbd) or
adjust it up or down based on hardware capabilities (sd).
Change blk_validate_limits to default max_sectors to the optimal I/O
size, or upgrade it to the preferred minimal I/O size if that is
larger than the kernel default if no optimal I/O size is provided based
on the logic in the SD driver.
This keeps the existing kernel default for drivers that do not provide
an io_opt or very big io_min value, but picks a much more useful
default for those who provide these hints, and allows to remove the
hacks to set the user max_sectors limit in nbd, rbd and sd.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 16d80c54ad ("rbd: set io_min, io_opt and discard_granularity to
alloc_size") lowered the io_opt size for rbd from objset_bytes which is
4MB for typical setup to alloc_size which is typically 64KB.
The commit mostly talks about discard behavior and does mention io_min
in passing. Reducing io_opt means reducing the readahead size, which
seems counter-intuitive given that rbd currently abuses the user
max_sectors setting to actually increase the I/O size. Switch back
to the old setting to allow larger reads (the readahead size despite it's
name actually limits the size of any buffered read) and to prepare
for using io_opt in the max_sectors calculation and getting drivers out
of the business of overriding the max_user_sectors value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If fallcate is implemented but zero and discard operations are not
supported by the filesystem the backing file is on we continue to fill
dmesg with errors from the blk_mq_end_request() since each time we call
fallocate() on the loop device the EOPNOTSUPP error from lo_fallocate()
ends up propagated into the block layer. In the end syscall succeeds
since the blkdev_issue_zeroout() falls back to writing zeroes which
makes the errors even more misleading and confusing.
How to reproduce:
1. make sure /tmp is mounted as tmpfs
2. dd if=/dev/zero of=/tmp/disk.img bs=1M count=100
3. losetup /dev/loop0 /tmp/disk.img
4. mkfs.ext2 /dev/loop0
5. dmesg |tail
[710690.898214] operation not supported error, dev loop0, sector 204672 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.898279] operation not supported error, dev loop0, sector 522 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.898603] operation not supported error, dev loop0, sector 16906 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.898917] operation not supported error, dev loop0, sector 32774 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.899218] operation not supported error, dev loop0, sector 49674 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.899484] operation not supported error, dev loop0, sector 65542 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.899743] operation not supported error, dev loop0, sector 82442 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.900015] operation not supported error, dev loop0, sector 98310 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.900276] operation not supported error, dev loop0, sector 115210 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[710690.900546] operation not supported error, dev loop0, sector 131078 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
This patch changes the lo_fallocate() to clear the flags for zero and
discard operations if we get EOPNOTSUPP from the backing file fallocate
callback, that way we at least stop spewing errors after the first
unsuccessful try.
CC: Jan Kara <jack@suse.cz>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240613163817.22640-1-chrubis@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make it again possible for sparse to verify that blk_status_t and Unix
error codes are used in the proper context by making nbd_send_cmd()
return a blk_status_t instead of an integer.
No functionality has been changed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[ bvanassche: added description and made two small formatting changes ]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240604221531.327131-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A zoned device with a smaller last zone together with a zone capacity
smaller than the zone size does make any sense as that does not
correspond to any possible setup for a real device:
1) For ZNS and zoned UFS devices, all zones are always the same size.
2) For SMR HDDs, all zones always have the same capacity.
In other words, if we have a smaller last runt zone, then this zone
capacity should always be equal to the zone size.
Add a check in null_init_zoned_dev() to prevent a configuration to have
both a smaller zone size and a zone capacity smaller than the zone size.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240530054035.491497-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When powering on a null_blk device that is not already on, the return
value ret that is initialized to be count is reused to check the return
value of null_add_dev(), leading to nullb_device_power_store() to return
null_add_dev() return value (0 on success) instead of "count".
So make sure to set ret to be equal to count when there are no errors.
Fixes: a2db328b08 ("null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20240527043445.235267-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more block updates from Jens Axboe:
"Followup block updates, mostly due to NVMe being a bit late to the
party. But nothing major in there, so not a big deal.
In detail, this contains:
- NVMe pull request via Keith:
- Fabrics connection retries (Daniel, Hannes)
- Fabrics logging enhancements (Tokunori)
- RDMA delete optimization (Sagi)
- ublk DMA alignment fix (me)
- null_blk sparse warning fixes (Bart)
- Discard support for brd (Keith)
- blk-cgroup list corruption fixes (Ming)
- blk-cgroup stat propagation fix (Waiman)
- Regression fix for plugging stall with md (Yu)
- Misc fixes or cleanups (David, Jeff, Justin)"
* tag 'block-6.10-20240523' of git://git.kernel.dk/linux: (24 commits)
null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'
blk-throttle: remove unused struct 'avg_latency_bucket'
block: fix lost bio for plug enabled bio based device
block: t10-pi: add MODULE_DESCRIPTION()
blk-mq: add helper for checking if one CPU is mapped to specified hctx
blk-cgroup: Properly propagate the iostat update up the hierarchy
blk-cgroup: fix list corruption from reorder of WRITE ->lqueued
blk-cgroup: fix list corruption from resetting io stat
cdrom: rearrange last_media_change check to avoid unintentional overflow
nbd: Fix signal handling
nbd: Remove a local variable from nbd_send_cmd()
nbd: Improve the documentation of the locking assumptions
nbd: Remove superfluous casts
nbd: Use NULL to represent a pointer
brd: implement discard support
null_blk: Fix two sparse warnings
ublk_drv: set DMA alignment mask to 3
nvme-rdma, nvme-tcp: include max reconnects for reconnect logging
nvmet-rdma: Avoid o(n^2) loop in delete_ctrl
nvme: do not retry authentication failures
...
Pull tracing cleanup from Steven Rostedt:
"Remove second argument of __assign_str()
The __assign_str() macro logic of the TRACE_EVENT() macro was
optimized so that it no longer needs the second argument. The
__assign_str() is always matched with __string() field that takes a
field name and the source for that field:
__string(field, source)
The TRACE_EVENT() macro logic will save off the source value and then
use that value to copy into the ring buffer via the __assign_str().
Before commit c1fa617cae ("tracing: Rework __assign_str() and
__string() to not duplicate getting the string"), the __assign_str()
needed the second argument which would perform the same logic as the
__string() source parameter did. Not only would this add overhead, but
it was error prone as if the __assign_str() source produced something
different, it may not have allocated enough for the string in the ring
buffer (as the __string() source was used to determine how much to
allocate)
Now that the __assign_str() just uses the same string that was used in
__string() it no longer needs the source parameter. It can now be
removed"
* tag 'trace-assign-str-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/treewide: Remove second parameter of __assign_str()
Pull virtio updates from Michael Tsirkin:
"Several new features here:
- virtio-net is finally supported in vduse
- virtio (balloon and mem) interaction with suspend is improved
- vhost-scsi now handles signals better/faster
And fixes, cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits)
virtio-pci: Check if is_avq is NULL
virtio: delete vq in vp_find_vqs_msix() when request_irq() fails
MAINTAINERS: add Eugenio Pérez as reviewer
vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API
vp_vdpa: don't allocate unused msix vectors
sound: virtio: drop owner assignment
fuse: virtio: drop owner assignment
scsi: virtio: drop owner assignment
rpmsg: virtio: drop owner assignment
nvdimm: virtio_pmem: drop owner assignment
wifi: mac80211_hwsim: drop owner assignment
vsock/virtio: drop owner assignment
net: 9p: virtio: drop owner assignment
net: virtio: drop owner assignment
net: caif: virtio: drop owner assignment
misc: nsm: drop owner assignment
iommu: virtio: drop owner assignment
drm/virtio: drop owner assignment
gpio: virtio: drop owner assignment
firmware: arm_scmi: virtio: drop owner assignment
...
Writing 'power' and 'submit_queues' concurrently will trigger kernel
panic:
Test script:
modprobe null_blk nr_devices=0
mkdir -p /sys/kernel/config/nullb/nullb0
while true; do echo 1 > submit_queues; echo 4 > submit_queues; done &
while true; do echo 1 > power; echo 0 > power; done
Test result:
BUG: kernel NULL pointer dereference, address: 0000000000000148
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:__lock_acquire+0x41d/0x28f0
Call Trace:
<TASK>
lock_acquire+0x121/0x450
down_write+0x5f/0x1d0
simple_recursive_removal+0x12f/0x5c0
blk_mq_debugfs_unregister_hctxs+0x7c/0x100
blk_mq_update_nr_hw_queues+0x4a3/0x720
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x79/0xf0 [null_blk]
configfs_write_iter+0x119/0x1e0
vfs_write+0x326/0x730
ksys_write+0x74/0x150
This is because del_gendisk() can concurrent with
blk_mq_update_nr_hw_queues():
nullb_device_power_store nullb_apply_submit_queues
null_del_dev
del_gendisk
nullb_update_nr_hw_queues
if (!dev->nullb)
// still set while gendisk is deleted
return 0
blk_mq_update_nr_hw_queues
dev->nullb = NULL
Fix this problem by resuing the global mutex to protect
nullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.
Fixes: 45919fbfe1 ("null_blk: Enable modifying 'submit_queues' after an instance has been configured")
Reported-and-tested-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAHj4cs9LgsHLnjg8z06LQ3Pr5cax-+Ps+xT7AP7TPnEjStuwZA@mail.gmail.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Link: https://lore.kernel.org/r/20240523153934.1937851-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.
This means that with:
__string(field, mystring)
Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.
There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:
git grep -l __assign_str | while read a ; do
sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
mv /tmp/test-file $a;
done
I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.
Note, the same updates will need to be done for:
__assign_str_len()
__assign_rel_str()
__assign_rel_str_len()
I tested this with both an allmodconfig and an allyesconfig (build only for both).
[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org> # xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
John Garry
Damien Le Moal
Christoph Hellwig
Zhu Yanjun
David Hildenbrand
Gulam Mohamed
Jeff Johnson
Jens Axboe
Andreas Hindborg
Cyril Hrubis
Linus Torvalds
Yu Kuai
Steven Rostedt (Google)