Instead of returning an inconclusive value of NULL for an error in calling
bio_split(), return a ERR_PTR() always.
Also remove the BUG_ON() calls, and WARN_ON_ONCE() instead. Indeed, since
almost all callers don't check the return code from bio_split(), we'll
crash anyway (for those failures).
Fix up the only user which checks bio_split() return code today (directly
or indirectly), blk_crypto_fallback_split_bio_if_needed(). The md/bcache
code does check the return code in cached_dev_cache_miss() ->
bio_next_split() -> bio_split(), but only to see if there was a split, so
there would be no change in behaviour here (when returning a ERR_PTR()).
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241111112150.3756529-2-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In ublk_ch_mmap(), queue id is calculated in the following way:
(vma->vm_pgoff << PAGE_SHIFT) / `max_cmd_buf_size`
'max_cmd_buf_size' is equal to
`UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc)`
and UBLK_MAX_QUEUE_DEPTH is 4096 and part of UAPI, so 'max_cmd_buf_size'
is always page aligned in 4K page size kernel. However, it isn't true in
64K page size kernel.
Fixes the issue by always rounding up 'max_cmd_buf_size' with PAGE_SIZE.
Cc: stable@vger.kernel.org
Fixes: 71f28f3136 ("ublk_drv: add io_uring based userspace block driver")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241111110718.1394001-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In case of an early failure in dasd_init, dasd_proc_init is never
called and /proc/dasd* files are never created. That can happen, for
example, if an incompatible or incorrect argument is provided to the
dasd_mod.dasd= kernel parameter.
However, the attempted removal of /proc/dasd* files causes 8 warnings
and backtraces in this case. 4 on the error path within dasd_init and
4 when the dasd module is unloaded. Notice the "removing permanent
/proc entry 'devices'" message that is caused by the dasd_proc_exit
function trying to remove /proc/devices instead of /proc/dasd/devices
since dasd_proc_root_entry is NULL and /proc/devices is indeed
permanent. Example:
------------[ cut here ]------------
removing permanent /proc entry 'devices'
WARNING: CPU: 6 PID: 557 at fs/proc/generic.c:701 remove_proc_entry+0x22e/0x240
CPU: 6 PID: 557 Comm: modprobe Not tainted 6.10.5-1-default #1
openSUSE Tumbleweed f6917bfd6e5a5c7a7e900e0e3b517786fb5c6301
Hardware name: QEMU 8561 QEMU (KVM/Linux)
Krnl PSW : 0704c00180000000 000003fffed0e9f2 (remove_proc_entry+0x232/0x240)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 000003ff00000027 000003ff00000023 0000000000000028 000002f200000000
000002f3f05bec20 0000037ffecfb7d0 000003ffffdabab0 000003ff7ee4ec72
000003ff7ee4ec72 0000000000000007 000002f280e22600 000002f280e22688
000003ffa252cfa0 0000000000010000 000003fffed0e9ee 0000037ffecfba38
Krnl Code: 000003fffed0e9e2: c020004e7017 larl %r2,000003ffff6dca10
000003fffed0e9e8: c0e5ffdfad24 brasl %r14,000003fffe904430
#000003fffed0e9ee: af000000 mc 0,0
>000003fffed0e9f2: a7f4ff4c brc 15,000003fffed0e88a
000003fffed0e9f6: 0707 bcr 0,%r7
000003fffed0e9f8: 0707 bcr 0,%r7
000003fffed0e9fa: 0707 bcr 0,%r7
000003fffed0e9fc: 0707 bcr 0,%r7
Call Trace:
[<000003fffed0e9f2>] remove_proc_entry+0x232/0x240
([<000003fffed0e9ee>] remove_proc_entry+0x22e/0x240)
[<000003ff7ef5a084>] dasd_proc_exit+0x34/0x60 [dasd_mod]
[<000003ff7ef560c2>] dasd_exit+0x22/0xc0 [dasd_mod]
[<000003ff7ee5a26e>] dasd_init+0x26e/0x280 [dasd_mod]
[<000003fffe8ac9d0>] do_one_initcall+0x40/0x220
[<000003fffe9bc758>] do_init_module+0x78/0x260
[<000003fffe9bf3a6>] __do_sys_init_module+0x216/0x250
[<000003ffff37ac9e>] __do_syscall+0x24e/0x2d0
[<000003ffff38cca8>] system_call+0x70/0x98
Last Breaking-Event-Address:
[<000003fffef7ea20>] __s390_indirect_jump_r14+0x0/0x10
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
While the cause is a user failure, the dasd module should handle the
situation more gracefully. One of the simplest solutions is to make
removal of the /proc/dasd* entries idempotent.
Signed-off-by: Miroslav Franc <mfranc@suse.cz>
[ sth: shortened if clause ]
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20241108133913.3068782-2-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull raid5 fix from Song.
* tag 'md-6.13-20241107' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
MAINTAINERS: Make Yu Kuai co-maintainer of md/raid subsystem
md/raid5: Wait sync io to finish before changing group cnt
PAGE_SIZE may be 64K, and the max block size can be PAGE_SIZE, so any
variable for holding block size can't be defined as 'unsigned short'.
Unfortunately commit 473516b361 ("loop: use the atomic queue limits
update API") passes 'bsize' with type of 'unsigned short' to
loop_reconfigure_limits(), and causes LTP/ioctl_loop06 test failure:
12 ioctl_loop06.c:76: TINFO: Using LOOP_SET_BLOCK_SIZE with arg > PAGE_SIZE
13 ioctl_loop06.c:59: TFAIL: Set block size succeed unexpectedly
...
18 ioctl_loop06.c:76: TINFO: Using LOOP_CONFIGURE with block_size > PAGE_SIZE
19 ioctl_loop06.c:59: TFAIL: Set block size succeed unexpectedly
Fixes the issue by defining 'block size' variable with 'unsigned int', which is
aligned with block layer's definition.
(improve commit log & add fixes tag)
Fixes: 473516b361 ("loop: use the atomic queue limits update API")
Cc: John Garry <john.g.garry@oracle.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Li Wang <liwang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241109022744.1126003-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In the past couple years, Yu Kuai has been making solid contributions
to md/raid subsystem. Make Yu Kuai a co-maintainer.
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241108014112.2098079-1-song@kernel.org
Signed-off-by: Song Liu <song@kernel.org>
One customer reports a bug: raid5 is hung when changing thread cnt
while resync is running. The stripes are all in conf->handle_list
and new threads can't handle them.
Commit b39f35ebe8 ("md: don't quiesce in mddev_suspend()") removes
pers->quiesce from mddev_suspend/resume. Before this patch, mddev_suspend
needs to wait for all ios including sync io to finish. Now it's used
to only wait normal io.
Fix this by calling raid5_quiesce from raid5_store_group_thread_cnt
directly to wait all sync requests to finish before changing the group
cnt.
Fixes: b39f35ebe8 ("md: don't quiesce in mddev_suspend()")
Cc: stable@vger.kernel.org
Signed-off-by: Xiao Ni <xni@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241106095124.74577-1-xni@redhat.com
Signed-off-by: Song Liu <song@kernel.org>
elevator_init_mq() is only called at the entry of add_disk_fwnode() when
disk IO isn't allowed yet.
So not verify io lock(q->io_lockdep_map) for freeze & unfreeze in
elevator_init_mq().
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Lai Yi <yi1.lai@linux.intel.com>
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/20241031133723.303835-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Unfreeze queue after returning from blk_mark_disk_dead(), this way at
least allows us to verify queue freeze correctly with lockdep.
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241031133723.303835-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No one use blk_freeze_queue(), so remove it and the obsolete comment.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241031133723.303835-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Turn the private disk_zone_is_conv() function in blk-zoned.c into a
public and documented bdev_zone_is_seq() helper with the inverse
polarity of the original function, also adding a check for non-zoned
devices so that all file systems can use the helper, even with a regular
block device.
Suggested-by: Christoph Hellwig <hch@lst.de>
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/20241107064300.227731-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Per Documentation/filesystems/sysfs.rst, show() should only use
sysfs_emit() or sysfs_emit_at() when formatting the value to be
returned to user space.
No functional change intended.
Signed-off-by: zhangguopeng <zhangguopeng@kylinos.cn>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241107104258.29742-1-zhangguopeng@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull MD changes from Song:
"1. Enhance handling of faulty and blocked devices, by Yu Kuai.
2. raid5-ppl atomic improvement, by Uros Bizjak.
3. md-bitmap fix, by Yuan Can."
* tag 'md-6.13-20241105' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
md/md-bitmap: Add missing destroy_work_on_stack()
md/raid5: don't set Faulty rdev for blocked_rdev
md/raid10: don't wait for Faulty rdev in wait_blocked_rdev()
md/raid1: don't wait for Faulty rdev in wait_blocked_rdev()
md/raid1: factor out helper to handle blocked rdev from raid1_write_request()
md: don't record new badblocks for faulty rdev
md: don't wait faulty rdev in md_wait_for_blocked_rdev()
md: add a new helper rdev_blocked()
md/raid5-ppl: Use atomic64_inc_return() in ppl_new_iounit()
pcim_iomap_table() and pcim_request_regions() have been deprecated in
commit e354bb84a4 ("PCI: Deprecate pcim_iomap_table(),
pcim_iomap_regions_request_all()") and commit d140f80f60 ("PCI:
Deprecate pcim_iomap_regions() in favor of pcim_iomap_region()"),
respectively.
Replace these functions with pcim_iomap_region().
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://lore.kernel.org/r/20241106145249.108996-2-pstanner@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit add missed destroy_work_on_stack() operations for
unplug_work.work in bitmap_unplug_async().
Fixes: a022325ab9 ("md/md-bitmap: add a new helper to unplug bitmap asynchrously")
Cc: stable@vger.kernel.org
Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241105130105.127336-1-yuancan@huawei.com
Signed-off-by: Song Liu <song@kernel.org>
Faulty rdev should never be accessed anymore, hence there is no point to
wait for bad block to be acknowledged in this case while handling write
request.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-8-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Faulty rdev should never be accessed anymore, hence there is no point to
wait for bad block to be acknowledged in this case while handling write
request.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-7-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Faulty rdev should never be accessed anymore, hence there is no point to
wait for bad block to be acknowledged in this case while handling write
request.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-6-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Currently raid1 is preparing IO for underlying disks while checking if
any disk is blocked, if so allocated resources must be released, then
waiting for rdev to be unblocked and try to prepare IO again.
Make code cleaner by checking blocked rdev first, it doesn't matter if
rdev is blocked while issuing IO, the IO will wait for rdev to be
unblocked or not.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-5-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Faulty will be checked before issuing IO to the rdev, however, rdev can
be faulty at any time, hence it's possible that rdev_set_badblocks()
will be called for faulty rdev. In this case, mddev->sb_flags will be
set and some other path can be blocked by updating super block.
Since faulty rdev will not be accesed anymore, there is no need to
record new babblocks for faulty rdev and forcing updating super block.
Noted this is not a bugfix, just prevent updating superblock in some
corner cases, and will help to slice a bug related to external
metadata[1], testing also shows that devices are removed faster in the
case IO error.
[1] https://lore.kernel.org/all/f34452df-810b-48b2-a9b4-7f925699a9e7@linux.intel.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-4-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
md_wait_for_blocked_rdev() is called for write IO while rdev is
blocked, howerver, rdev can be faulty after choosing this rdev to write,
and faulty rdev should never be accessed anymore, hence there is no point
to wait for faulty rdev to be unblocked.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-3-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
The helper will be used in later patches for raid1/raid10/raid5, the
difference is that Faulty rdev with unacknowledged bad block will not
be considered blocked.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Link: https://lore.kernel.org/r/20241031033114.3845582-2-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
to use optimized implementation and ease register pressure around
the primitive for targets that implement optimized variant.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Song Liu <song@kernel.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Link: https://lore.kernel.org/r/20241007084831.48067-1-ubizjak@gmail.com
Signed-off-by: Song Liu <song@kernel.org>
max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper. This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.
Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With the lock layer zone append emulation, we are now always setting a
max_zone_append_sectors value for zoned devices and this check can't
ever trigger.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Listing every single features that needs to be pre-set by stacking
drivers does not scale.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104054218.45596-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
.bi_size of bvec iterator should be initialized as real max size for
walking, and .bi_bvec_done just counts how many bytes need to be
skipped in the 1st bvec, so .bi_size isn't related with .bi_bvec_done.
This patch fixes bvec iterator initialization, and the inner `size`
check isn't needed any more, so revert Eric Dumazet's commit
7bc802acf193 ("iov-iter: do not return more bytes than requested in
iov_iter_extract_bvec_pages()").
Cc: Eric Dumazet <edumazet@google.com>
Fixes: e4e535bff2 ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reported-by: syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com
Tested-by: syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A bdev discard granularity is always at least SECTOR_SIZE, so don't check
for a zero value.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241101092215.422428-1-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is only used by the nvmet zns passthrough code, which can trivially
just use bio_add_pc_page and do the sanity check for the max zone append
limit itself.
All future zoned file systems should follow the btrfs lead and let the
upper layers fill up bios unlimited by hardware constraints and split
them to the limits in the I/O submission handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20241030051859.280923-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This code is unused, and all future zoned file systems should follow
the btrfs lead of splitting the bios themselves to the zoned limits
in the I/O submission handler, because if they didn't they would be
hit by commit ed9832bc08 ("block: introduce folio awareness and add
a bigger size from folio") breaking this code when the zone append
limit (that is usually the max_hw_sectors limit) is smaller than the
largest possible folio size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20241030051859.280923-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Initialize bi.bi_idx as 0 before iterating over bvec, otherwise
garbage data can be used as ->bi_idx.
Cc: Christoph Hellwig <hch@lst.de>
Reported-and-tested-by: Klara Modin <klarasmodin@gmail.com>
Fixes: e4e535bff2 ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The seed is only used for kernel generation and verification. That
doesn't happen for user buffers, so passing the seed around doesn't
accomplish anything.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20241016201309.1090320-1-kbusch@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
My colleague Wupeng found the following problems during fault injection:
BUG: unable to handle page fault for address: fffffbfff809d073
PGD 6e648067 P4D 123ec8067 PUD 123ec4067 PMD 100e38067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 5 UID: 0 PID: 755 Comm: modprobe Not tainted 6.12.0-rc3+ #17
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:__asan_load8+0x4c/0xa0
...
Call Trace:
<TASK>
blkdev_put_whole+0x41/0x70
bdev_release+0x1a3/0x250
blkdev_release+0x11/0x20
__fput+0x1d7/0x4a0
task_work_run+0xfc/0x180
syscall_exit_to_user_mode+0x1de/0x1f0
do_syscall_64+0x6b/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
loop_init() is calling loop_add() after __register_blkdev() succeeds and
is ignoring disk_add() failure from loop_add(), for loop_add() failure
is not fatal and successfully created disks are already visible to
bdev_open().
brd_init() is currently calling brd_alloc() before __register_blkdev()
succeeds and is releasing successfully created disks when brd_init()
returns an error. This can cause UAF for the latter two case:
case 1:
T1:
modprobe brd
brd_init
brd_alloc(0) // success
add_disk
disk_scan_partitions
bdev_file_open_by_dev // alloc file
fput // won't free until back to userspace
brd_alloc(1) // failed since mem alloc error inject
// error path for modprobe will release code segment
// back to userspace
__fput
blkdev_release
bdev_release
blkdev_put_whole
bdev->bd_disk->fops->release // fops is freed now, UAF!
case 2:
T1: T2:
modprobe brd
brd_init
brd_alloc(0) // success
open(/dev/ram0)
brd_alloc(1) // fail
// error path for modprobe
close(/dev/ram0)
...
/* UAF! */
bdev->bd_disk->fops->release
Fix this problem by following what loop_init() does. Besides,
reintroduce brd_devices_mutex to help serialize modifications to
brd_list.
Fixes: 7f9b348cb5 ("brd: convert to blk_alloc_disk/blk_cleanup_disk")
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241030034914.907829-1-yangerkun@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a helper to get the queue_limits from the bdev without having to
poke into the request_queue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The iov_iter_extract_pages interface allows to return physically
discontiguous pages, as long as all but the first and last page
in the array are page aligned and page size. Rewrite
iov_iter_extract_bvec_pages to take advantage of that instead of only
returning ranges of physically contiguous pages.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
[hch: minor cleanups, new commit log]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241024050021.627350-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
nvme_start_freeze() and nvme_unfreeze() may be called from same context,
so switch them to call non_owner variant of start_freeze/unfreeze queue.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241025003722.3630252-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Commit a6088845c2 ("block: kyber: make kyber more friendly with merging")
removed the only blk_mq_flush_busy_ctxs() call from outside the block layer
core. Hence unexport blk_mq_flush_busy_ctxs().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20241023202850.3469279-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Make sure that the tag_list_lock mutex is not held any longer than
necessary. This change reduces latency if e.g. blk_mq_quiesce_tagset()
is called concurrently from more than one thread. This function is used
by the NVMe core and also by the UFS driver.
Reported-by: Peter Wang <peter.wang@mediatek.com>
Cc: Chao Leng <lengchao@huawei.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 414dd48e88 ("blk-mq: add tagset quiesce interface")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20241022181617.2716173-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The memory barriers in list_del_init_careful() and list_empty_careful()
in pairs already handle the proper ordering between data.got_token
and data.wq.entry. So remove the redundant explicit barriers. And also
change a "break" statement to "return" to avoid redundant calling of
finish_wait().
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/r/20241021085251.73353-1-songmuchun@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in block/fs prep patches for the atomic write support.
* for-6.13/block-atomic:
block: Add bdev atomic write limits helpers
fs/block: Check for IOCB_DIRECT in generic_atomic_write_valid()
block/fs: Pass an iocb to generic_atomic_write_valid()
When a process migrates to another cgroup and the original cgroup is deleted,
the restrictions of throttled bios cannot be removed. If the restrictions
are set too low, it will take a long time to complete these bios.
Refer to the process of deleting a disk to remove the restrictions and
issue bios when deleting the cgroup.
This makes difference on the behavior of throttled bios:
Before: the limit of the throttled bios can't be changed and the bios will
complete under this limit;
Now: the limit will be canceled and the throttled bios will be flushed
immediately.
References:
[1] https://lore.kernel.org/r/20220318130144.1066064-4-ming.lei@redhat.com
[2] https://lore.kernel.org/all/da861d63-58c6-3ca0-2535-9089993e9e28@huaweicloud.com/
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240817071108.1919729-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
