Commit 4601b4b130 ("block: reopen the device in blkdev_reread_part")
lost the propagation of I/O errors from the low-level read of the
partition table to the user space caller of the BLKRRPART.
Apparently some user space relies on, so restore the propagation. This
isn't exactly pretty as other block device open calls explicitly do not
are about these errors, so add a new BLK_OPEN_STRICT_SCAN to opt into
the error propagation.
Fixes: 4601b4b130 ("block: reopen the device in blkdev_reread_part")
Reported-by: Saranya Muruganandam <saranyamohan@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240417144743.2277601-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
While monitoring the throttle time of IO from iocost, it's found that
such time is always zero after the io_schedule() from ioc_rqos_throttle,
for example, with the following debug patch:
+ printk("%s-%d: %s enter %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());
while (true) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (wait.committed)
break;
io_schedule();
}
+ printk("%s-%d: %s exit %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());
It can be observerd that blk_time_get_ns() always return the same time:
[ 1068.096579] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.272587] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.274389] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.472690] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.474485] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.672656] fio-1268: ioc_rqos_throttle exit 1067901962288
[ 1068.674451] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.872655] fio-1268: ioc_rqos_throttle exit 1067901962288
And I think the root cause is that 'PF_BLOCK_TS' is always cleared
by blk_flush_plug() before scheduel(), hence blk_plug_invalidate_ts()
will never be called:
blk_time_get_ns
plug->cur_ktime = ktime_get_ns();
current->flags |= PF_BLOCK_TS;
io_schedule:
io_schedule_prepare
blk_flush_plug
__blk_flush_plug
/* the flag is cleared, while time is not */
current->flags &= ~PF_BLOCK_TS;
schedule
sched_update_worker
/* the flag is not set, hence plug->cur_ktime is not cleared */
if (tsk->flags & PF_BLOCK_TS)
blk_plug_invalidate_ts()
blk_time_get_ns
/* got the time stashed before schedule */
return plug->cur_ktime;
Fix the problem by clearing cached time in __blk_flush_plug().
Fixes: 06b23f92af ("block: update cached timestamp post schedule/preemption")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240411032349.3051233-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Multiple gendisk instances can allocated/added for single request queue
in case of disk rebind. blkg may still stay in q->blkg_list when calling
blkcg_init_disk() for rebind, then q->blkg_list becomes corrupted.
Fix the list corruption issue by:
- add blkg_init_queue() to initialize q->blkg_list & q->blkcg_mutex only
- move calling blkg_init_queue() into blk_alloc_queue()
The list corruption should be started since commit f1c006f1c6 ("blk-cgroup:
synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
which delays removing blkg from q->blkg_list into blkg_free_workfn().
Fixes: f1c006f1c6 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
Fixes: 1059699f87 ("block: move blkcg initialization/destroy into disk allocation/release handler")
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240407125910.4053377-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
UBSAN catches undefined behavior in blk-iocost, where sometimes
iocg->delay is shifted right by a number that is too large,
resulting in undefined behavior on some architectures.
[ 186.556576] ------------[ cut here ]------------
UBSAN: shift-out-of-bounds in block/blk-iocost.c:1366:23
shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long')
CPU: 16 PID: 0 Comm: swapper/16 Tainted: G S E N 6.9.0-0_fbk700_debug_rc2_kbuilder_0_gc85af715cac0 #1
Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A23 12/08/2020
Call Trace:
<IRQ>
dump_stack_lvl+0x8f/0xe0
__ubsan_handle_shift_out_of_bounds+0x22c/0x280
iocg_kick_delay+0x30b/0x310
ioc_timer_fn+0x2fb/0x1f80
__run_timer_base+0x1b6/0x250
...
Avoid that undefined behavior by simply taking the
"delay = 0" branch if the shift is too large.
I am not sure what the symptoms of an undefined value
delay will be, but I suspect it could be more than a
little annoying to debug.
Signed-off-by: Rik van Riel <riel@surriel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Jens Axboe <axboe@kernel.dk>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240404123253.0f58010f@imladris.surriel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no check for overflow of 'start + len' in blk_ioctl_discard().
Hung task occurs if submit an discard ioctl with the following param:
start = 0x80000000000ff000, len = 0x8000000000fff000;
Add the overflow validation now.
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240329012319.2034550-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'block-6.9-20240329' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
"Small round of minor fixes or cleanups for the 6.9-rc2 kernel, one
fixing an issue introduced in 6.8"
* tag 'block-6.9-20240329' of git://git.kernel.dk/linux:
block: Do not force full zone append completion in req_bio_endio()
block: don't reject too large max_user_sectors in blk_validate_limits
block: Make blk_rq_set_mixed_merge() static
This reverts commit 748dc0b65e.
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 748dc0b65e ("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: 748dc0b65e ("block: fix partial zone append completion handling in req_bio_endio()")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240328004409.594888-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We already cap down the actual max_sectors to the max of the hardware
and user limit, so don't reject the configuration.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240326060745.2349154-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 8e756373d7 ("block: Move bio merge related functions into
blk-merge.c"), blk_rq_set_mixed_merge() has only been referenced in
blk-merge.c, so make it static.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240325083501.2816408-1-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'vfs-6.9-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
"This contains a few small fixes for this merge window:
- Undo the hiding of silly-rename files in afs. If they're hidden
they can't be deleted by rm manually anymore causing regressions
- Avoid caching the preferred address for an afs server to avoid
accidently overriding an explicitly specified preferred server
address
- Fix bad stat() and rmdir() interaction in afs
- Take a passive reference on the superblock when opening a block
device so the holder is available to concurrent callers from the
block layer
- Clear private data pointer in fscache_begin_operation() to avoid it
being falsely treated as valid"
* tag 'vfs-6.9-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fscache: Fix error handling in fscache_begin_operation()
fs,block: get holder during claim
afs: Fix occasional rmdir-then-VNOVNODE with generic/011
afs: Don't cache preferred address
afs: Revert "afs: Hide silly-rename files from userspace"
Now that we open block devices as files we need to deal with the
realities that closing is a deferred operation. An operation on the
block device such as e.g., freeze, thaw, or removal that runs
concurrently with umount, tries to acquire a stable reference on the
holder. The holder might already be gone though. Make that reliable by
grabbing a passive reference to the holder during bdev_open() and
releasing it during bdev_release().
Fixes: f3a608827d ("bdev: open block device as files") # mainline only
Reported-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/r/ZfEQQ9jZZVes0WCZ@infradead.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reported-by: https://lore.kernel.org/r/CAHj4cs8tbDwKRwfS1=DmooP73ysM__xAb2PQc6XsAmWR+VuYmg@mail.gmail.com
Link: https://lore.kernel.org/r/20240315-freibad-annehmbar-ca68c375af91@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
This reverts commit 8a08c5fd89.
It turns out while this is a perfectly valid and long overdue thing to do
for user initiated discards / zeroing from the ioctl handler, it actually
breaks file system use of the discard helper by interrupting in places
the file system doesn't expect, and by leaving the bio chain in a state
that the file system callers of (at least) __blkdev_issue_discard do
not expect.
Revert the change for now, we'll redo it for the next merge window
after refactoring the code to better split the file system vs ioctl
callers and cleaning up a few other loose ends.
Reported-by: Chandan Babu R <chandanbabu@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240314021623.1908895-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 <dlemoal@kernel.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc: Zhiguo Niu <Zhiguo.Niu@unisoc.com>
Fixes: d47f9717e5 ("block/mq-deadline: use correct way to throttling write requests")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240313214218.1736147-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We should not have any callers of this from non-task context, but Jakub
ran [1] into one from blk-iocost. Rather than risk running into others,
or future ones, just limit blk_time_get_ns() to when it is called from
a task. Any other usage is invalid.
[1] https://lore.kernel.org/lkml/CAHk-=wiOaBLqarS2uFhM1YdwOvCX4CZaWkeyNDY1zONpbYw2ig@mail.gmail.com/
Fixes: da4c8c3d09 ("block: cache current nsec time in struct blk_plug")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit 8e0ef41286.
It's broken, and causes the boot to fail on encrypted volumes.
Reported-and-bisected-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/all/20240311235023.GA1205@cmpxchg.org/
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull block handle updates from Christian Brauner:
"Last cycle we changed opening of block devices, and opening a block
device would return a bdev_handle. This allowed us to implement
support for restricting and forbidding writes to mounted block
devices. It was accompanied by converting and adding helpers to
operate on bdev_handles instead of plain block devices.
That was already a good step forward but ultimately it isn't necessary
to have special purpose helpers for opening block devices internally
that return a bdev_handle.
Fundamentally, opening a block device internally should just be
equivalent to opening files. So now all internal opens of block
devices return files just as a userspace open would. Instead of
introducing a separate indirection into bdev_open_by_*() via struct
bdev_handle bdev_file_open_by_*() is made to just return a struct
file. Opening and closing a block device just becomes equivalent to
opening and closing a file.
This all works well because internally we already have a pseudo fs for
block devices and so opening block devices is simple. There's a few
places where we needed to be careful such as during boot when the
kernel is supposed to mount the rootfs directly without init doing it.
Here we need to take care to ensure that we flush out any asynchronous
file close. That's what we already do for opening, unpacking, and
closing the initramfs. So nothing new here.
The equivalence of opening and closing block devices to regular files
is a win in and of itself. But it also has various other advantages.
We can remove struct bdev_handle completely. Various low-level helpers
are now private to the block layer. Other helpers were simply
removable completely.
A follow-up series that is already reviewed build on this and makes it
possible to remove bdev->bd_inode and allows various clean ups of the
buffer head code as well. All places where we stashed a bdev_handle
now just stash a file and use simple accessors to get to the actual
block device which was already the case for bdev_handle"
* tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
block: remove bdev_handle completely
block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access
bdev: remove bdev pointer from struct bdev_handle
bdev: make struct bdev_handle private to the block layer
bdev: make bdev_{release, open_by_dev}() private to block layer
bdev: remove bdev_open_by_path()
reiserfs: port block device access to file
ocfs2: port block device access to file
nfs: port block device access to files
jfs: port block device access to file
f2fs: port block device access to files
ext4: port block device access to file
erofs: port device access to file
btrfs: port device access to file
bcachefs: port block device access to file
target: port block device access to file
s390: port block device access to file
nvme: port block device access to file
block2mtd: port device access to files
bcache: port block device access to files
...
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Merge tag 'vfs-6.9.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull iomap updates from Christian Brauner:
- Restore read-write hints in struct bio through the bi_write_hint
member for the sake of UFS devices in mobile applications. This can
result in up to 40% lower write amplification in UFS devices. The
patch series that builds on this will be coming in via the SCSI
maintainers (Bart)
- Overhaul the iomap writeback code. Afterwards ->map_blocks() is able
to map multiple blocks at once as long as they're in the same folio.
This reduces CPU usage for buffered write workloads on e.g., xfs on
systems with lots of cores (Christoph)
- Record processed bytes in iomap_iter() trace event (Kassey)
- Extend iomap_writepage_map() trace event after Christoph's
->map_block() changes to map mutliple blocks at once (Zhang)
* tag 'vfs-6.9.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
iomap: Add processed for iomap_iter
iomap: add pos and dirty_len into trace_iomap_writepage_map
block, fs: Restore the per-bio/request data lifetime fields
fs: Propagate write hints to the struct block_device inode
fs: Move enum rw_hint into a new header file
fs: Split fcntl_rw_hint()
fs: Verify write lifetime constants at compile time
fs: Fix rw_hint validation
iomap: pass the length of the dirty region to ->map_blocks
iomap: map multiple blocks at a time
iomap: submit ioends immediately
iomap: factor out a iomap_writepage_map_block helper
iomap: only call mapping_set_error once for each failed bio
iomap: don't chain bios
iomap: move the iomap_sector sector calculation out of iomap_add_to_ioend
iomap: clean up the iomap_alloc_ioend calling convention
iomap: move all remaining per-folio logic into iomap_writepage_map
iomap: factor out a iomap_writepage_handle_eof helper
iomap: move the PF_MEMALLOC check to iomap_writepages
iomap: move the io_folios field out of struct iomap_ioend
...
The helper function mac_fix_string is only required with CONFIG_PPC_PMAC,
add #if CONFIG_PPC_PMAC and #endif around the function.
Cleans up clang scan build warning:
block/partitions/mac.c:23:20: warning: unused function 'mac_fix_string' [-Wunused-function]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20240308133921.2058227-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
disk_stack_limits is unused now, remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed--by: Song Liu <song@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240303140150.5435-12-hch@lst.de
Commit 6d4e80db4e ("block: add capacity validation in
bdev_add_partition()") add check of partition's start and end sectors to
prevent exceeding the size of the disk when adding partitions. However,
there is still no check for resizing partitions now.
Move the check to blkpg_do_ioctl() to cover resizing partitions.
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240305032132.548958-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 43a7206b09 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the block_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240305-class_cleanup-block-v1-1-130bb27b9c72@marliere.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'vfs-6.9.rw_hint' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull write hint fix from Christian Brauner:
UFS devices are widely used in mobile applications, e.g. in smartphones.
UFS vendors need data lifetime information to achieve good performance.
Providing data lifetime information to UFS devices can result in up to
40% lower write amplification. Hence this patch series that restores the
bi_write_hint member in struct bio. After this patch series has been
merged, patches that implement data lifetime support in the SCSI disk
(sd) driver will be sent to the Linux kernel SCSI maintainer.
The following changes are included in this patch series:
- Improvements for the F_GET_RW_HINT and F_SET_RW_HINT fcntls.
- Move enum rw_hint into a new header file.
- Support F_SET_RW_HINT for block devices to make it easy to test data
lifetime support.
- Restore the bio.bi_write_hint member and restore support in the VFS
layer and also in the block layer for data lifetime information.
The shell script that has been used to test the patch series combined
with the SCSI patches is available at the end of this cover letter.
* tag 'vfs-6.9.rw_hint' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
block, fs: Restore the per-bio/request data lifetime fields
fs: Propagate write hints to the struct block_device inode
fs: Move enum rw_hint into a new header file
fs: Split fcntl_rw_hint()
fs: Verify write lifetime constants at compile time
fs: Fix rw_hint validation
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use queue_limits_set which validates the limits and takes care of
updating the readahead settings instead of directly assigning them to
the queue. For that make sure all limits are actually updated before
the assignment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20240228225653.947152-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a small wrapper around blk_stack_limits that allows passing a bdev
for the bottom device and prints an error in case of misaligned
device. The name fits into the new queue limits API and the intent is
to eventually replace disk_stack_limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240228225653.947152-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a small wrapper around queue_limits_commit_update for stacking
drivers that don't want to update existing limits, but set an
entirely new set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240228225653.947152-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For most of ARCHs, 'nr_cpus=1' is passed for kdump kernel, so
nr_hw_queues for each mapping is supposed to be 1 already.
More importantly, this way may cause trouble for driver, because blk-mq and
driver see different queue mapping since driver should setup hardware
queue setting before calling into allocating blk-mq tagset.
So not overriding nr_hw_queues and nr_maps for kdump kernel.
Cc: Wen Xiong <wenxiong@us.ibm.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240228040857.306483-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We just need to use the holder to indicate whether a block device open
was exclusive or not. We did use to do that before but had to give that
up once we switched to struct bdev_handle. Before struct bdev_handle we
only stashed stuff in file->private_data if this was an exclusive open
but after struct bdev_handle we always set file->private_data to a
struct bdev_handle and so we had to use bdev_handle->mode or
bdev_handle->holder. Now that we don't use struct bdev_handle anymore we
can revert back to the old behavior.
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-32-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Make it possible to detected a block device that was opened with
restricted write access based only on BLK_OPEN_WRITE and
bdev->bd_writers < 0 so we won't have to claim another FMODE_* flag.
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-31-adbd023e19cc@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
We can always go directly via:
* I_BDEV(bdev_file->f_inode)
* I_BDEV(bdev_file->f_mapping->host)
So keeping struct bdev in struct bdev_handle is redundant.
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-30-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Move both of them to the private block header. There's no caller in the
tree anymore that uses them directly.
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-28-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This may run from a kernel thread via device_add_disk(). So this could
also use __fput_sync() if we were worried about EBUSY. But when it is
called from a kernel thread it's always BLK_OPEN_READ so EBUSY can't
really happen even if we do BLK_OPEN_RESTRICT_WRITES or BLK_OPEN_EXCL.
Otherwise it's called from an ioctl on the block device which is only
called from userspace and can rely on task work.
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-3-adbd023e19cc@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add two new helpers to allow opening block devices as files.
This is not the final infrastructure. This still opens the block device
before opening a struct a file. Until we have removed all references to
struct bdev_handle we can't switch the order:
* Introduce blk_to_file_flags() to translate from block specific to
flags usable to pen a new file.
* Introduce bdev_file_open_by_{dev,path}().
* Introduce temporary sb_bdev_handle() helper to retrieve a struct
bdev_handle from a block device file and update places that directly
reference struct bdev_handle to rely on it.
* Don't count block device openes against the number of open files. A
bdev_file_open_by_{dev,path}() file is never installed into any
file descriptor table.
One idea that came to mind was to use kernel_tmpfile_open() which
would require us to pass a path and it would then call do_dentry_open()
going through the regular fops->open::blkdev_open() path. But then we're
back to the problem of routing block specific flags such as
BLK_OPEN_RESTRICT_WRITES through the open path and would have to waste
FMODE_* flags every time we add a new one. With this we can avoid using
a flag bit and we have more leeway in how we open block devices from
bdev_open_by_{dev,path}().
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-1-adbd023e19cc@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
The SLAB_MEM_SPREAD flag is already a no-op as of 6.8-rc1, remove
its usage so we can delete it from slab. No functional change.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lore.kernel.org/r/20240224134646.829105-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The logic in blk_mq_complete_need_ipi() assumes SMP systems where all
CPUs have equal compute capacities and only LLC cache can make
a different on perceived performance. But this assumption falls apart on
HMP systems where LLC is shared, but the CPUs have different capacities.
Staying local then can have a big performance impact if the IO request
was done from a CPU with higher capacity but the interrupt is serviced
on a lower capacity CPU.
Use the new cpus_equal_capacity() function to check if we need to send
an IPI.
Without the patch I see the BLOCK softirq always running on little cores
(where the hardirq is serviced). With it I can see it running on all
cores.
This was noticed after the topology change [1] where now on a big.LITTLE
we truly get that the LLC is shared between all cores where as in the
past it was being misrepresented for historical reasons. The logic
exposed a missing dependency on capacities for such systems where there
can be a big performance difference between the CPUs.
This of course introduced a noticeable change in behavior depending on
how the topology is presented. Leading to regressions in some workloads
as the performance of the BLOCK softirq on littles can be noticeably
worse on some platforms.
Worth noting that we could have checked for capacities being greater
than or equal instead for equality. This will lead to favouring higher
performance always. But opted for equality instead to match the
performance of the requester without making an assumption that can lead
to power trade-offs which these systems tend to be sensitive about. If
the requester would like to run faster, it's better to rely on the
scheduler to give the IO requester via some facility to run on a faster
core; and then if the interrupt triggered on a CPU with different
capacity we'll make sure to match the performance the requester is
supposed to run at.
[1] https://lpc.events/event/16/contributions/1342/attachments/962/1883/LPC-2022-Android-MC-Phantom-Domains.pdf
Signed-off-by: Qais Yousef <qyousef@layalina.io>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240223155749.2958009-3-qyousef@layalina.io
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Some of these block operations can access a significant capacity and
take longer than the user expected. A user may change their mind about
wanting to run that command and attempt to kill the process and do
something else with their device. But since the task is uninterruptable,
they have to wait for it to finish, which could be many hours.
Check for a fatal signal at each iteration so the user doesn't have to
wait for their regretted operation to complete naturally.
Reported-by: Conrad Meyer <conradmeyer@meta.com>
Tested-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240223155910.3622666-5-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is the same in two places, and another will be added soon. Create a
helper for it.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240223155910.3622666-4-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use min to calculate the next number of sectors like everyone else.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240223155910.3622666-3-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
