Using either of these is going to greatly confuse userspace, as they are
not valid symlink names and so creating the usual /dev/mapper/NAME
symlink will not be possible. As creating a device with either of these
names is almost certainly a userspace bug, just error out.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Typical userspace setups create a symlink under /dev/mapper with the
name of the device, but /dev/mapper/control is reserved for DM's control
device. Therefore, trying to create such a device is almost certain to
be a userspace bug.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
The version is fetched once in check_version(), which then does some
validation and then overwrites the version in userspace with the API
version supported by the kernel. copy_params() then fetches the version
from userspace *again*, and this time no validation is done. The result
is that the kernel's version number is completely controllable by
userspace, provided that userspace can win a race condition.
Fix this flaw by not copying the version back to the kernel the second
time. This is not exploitable as the version is not further used in the
kernel. However, it could become a problem if future patches start
relying on the version field.
Cc: stable@vger.kernel.org
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
The NUL terminator for each target parameter string must precede the
following 'struct dm_target_spec'. Otherwise, dm_split_args() might
corrupt this struct. Furthermore, the first 'struct dm_target_spec'
must come after the 'struct dm_ioctl', as if it overlaps too much
dm_split_args() could corrupt the 'struct dm_ioctl'.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Especially on 32-bit systems, it is possible for the pointer
arithmetic to overflow and cause a userspace pointer to be
dereferenced in the kernel.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Otherwise subsequent code, if given malformed input, could dereference
a misaligned 'struct dm_target_spec *'.
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> # use %zu
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
"Buffers" are buffers of the metadata/checksum area of dm-integrity.
They are always at most as large as a single metadata area on-disk, but
may be smaller.
Signed-off-by: Russell Harmon <eatnumber1@gmail.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
The kernel already has a helper to print a hexdump of a small
buffer via pointer extension. Use that instead of open coded
variant.
In long term it helps to kill pr_cont() or at least narrow down
its use.
Note, the format is slightly changed, i.e. the trailing space is
always printed. Also the IV dump is limited by 64 bytes which seems
fine.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Also rename disable_passdown_if_not_supported to
disable_discard_passdown_if_not_supported.
And fold passdown_enabled() into only caller.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Update dm_io_acct() to eliminate most dm_io struct accesses if both
block core's IO stats and dm-stats are disabled.
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Commit bc58ba9468 ("block: add sysfs file for controlling io stats
accounting") allowed users to turn off disk stat accounting completely
by checking if queue flag QUEUE_FLAG_IO_STAT is set. In dm, this flag
is neither set nor checked: so block-core's io stats are continuously
counted and cannot be turned off.
Add support for turning off block-core's io stats accounting for dm.
Set QUEUE_FLAG_IO_STAT for dm's request_queue. If QUEUE_FLAG_IO_STAT
is set when an io starts, record the need for block core's io stats by
setting the DM_IO_BLK_STAT dm_io flag to avoid io stats being disabled
in the middle of the io.
DM statistics (dm-stats) is independent of block-core's io stats and
remains unchanged.
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.
It is less verbose and it improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
As described in commit 8111964f1b ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be
triggered because shrinker_rwsem currently needs to held by
dm_pool_abort_metadata() as a side-effect of thin-pool metadata
operation failure.
The following three problem scenarios have been noticed:
1) Described by commit 8111964f1b ("dm thin: Fix ABBA deadlock between
shrink_slab and dm_pool_abort_metadata")
2) shrinker_rwsem and throttle->lock
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
super_cache_scan
prune_icache_sb
dispose_list
evict
ext4_evict_inode
ext4_clear_inode
ext4_discard_preallocations
ext4_mb_load_buddy_gfp
ext4_mb_init_cache
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
ext4_commit_super
...
dm_submit_bio
do_worker
throttle_work_update
down_write(&t->lock) -- LOCK B
process_deferred_bios
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
down_write(&shrinker_rwsem)
-- LOCK A
thin_map
thin_bio_map
thin_defer_bio_with_throttle
throttle_lock
down_read(&t->lock) - LOCK B
3) shrinker_rwsem and wait_on_buffer
P1(drop cache) P2(kworker)
drop_caches_sysctl_handler
drop_slab
shrink_slab
down_read(&shrinker_rwsem) - LOCK A
do_shrink_slab
...
ext4_wait_block_bitmap
__ext4_error
ext4_handle_error
jbd2_journal_abort
jbd2_journal_update_sb_errno
jbd2_write_superblock
submit_bh
// LOCK B
// RELEASE B
do_worker
throttle_work_update
down_write(&t->lock) - LOCK B
process_deferred_bios
process_bio
commit
metadata_operation_failed
dm_pool_abort_metadata
dm_block_manager_create
dm_bufio_client_create
register_shrinker
register_shrinker_prepared
down_write(&shrinker_rwsem) - LOCK A
bio_endio
wait_on_buffer
__wait_on_buffer
Fix these by resetting dm_bufio_client without holding shrinker_rwsem.
Fixes: 8111964f1b ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata")
Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
If the user specifies invalid AEAD cipher, dm-crypt should return the
error returned from crypt_ctr_auth_spec, not -ENOMEM.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Removes assumptions about what might follow the discard setup code
(previously the code would return early if discards not enabled).
Makes it possible to add more capabilites to the end of each .io_hints
method (which is the natural thing to do when adding new features).
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
The random_read_corrupt and random_write_corrupt options corrupt a
random byte in a bio with the provided probability. The corruption
only happens in the "down" interval.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
dm-flakey has an option to corrupt write bios. It corrupts the memory that
is being written. This can cause system crashes or security bugs - for
example, if the user writes a shared library code with O_DIRECT flag to a
dm-flakey device, it corrupts the memory for all users that have the
shared library mapped.
Fix this bug by cloning the bio and corrupting the clone rather than
the original.
Also drop the test for ZERO_PAGE(0) - it can't happen because we write
the cloned pages.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Pull NVMe updates from Keith:
"nvme updates for Linux 6.5
- Various cleanups all around (Irvin, Chaitanya, Christophe)
- Better struct packing (Christophe JAILLET)
- Reduce controller error logs for optional commands (Keith)
- Support for >=64KiB block sizes (Daniel Gomez)
- Fabrics fixes and code organization (Max, Chaitanya, Daniel Wagner)"
* tag 'nvme-6.5-2023-06-16' of git://git.infradead.org/nvme: (27 commits)
nvme: forward port sysfs delete fix
nvme: skip optional id ctrl csi if it failed
nvme-core: use nvme_ns_head_multipath instead of ns->head->disk
nvmet-fcloop: Do not wait on completion when unregister fails
nvme-fabrics: open code __nvmf_host_find()
nvme-fabrics: error out to unlock the mutex
nvme: Increase block size variable size to 32-bit
nvme-fcloop: no need to return from void function
nvmet-auth: remove unnecessary break after goto
nvmet-auth: remove some dead code
nvme-core: remove redundant check from nvme_init_ns_head
nvme: move sysfs code to a dedicated sysfs.c file
nvme-fabrics: prevent overriding of existing host
nvme-fabrics: check hostid using uuid_equal
nvme-fabrics: unify common code in admin and io queue connect
nvmet: reorder fields in 'struct nvmefc_fcp_req'
nvmet: reorder fields in 'struct nvme_dhchap_queue_context'
nvmet: reorder fields in 'struct nvmf_ctrl_options'
nvme: reorder fields in 'struct nvme_ctrl'
nvmet: reorder fields in 'struct nvmet_sq'
...
We had a late fix that modified nvme_sysfs_delete() after the staging
branch for the next merge window relocated the function to a new file.
Port commit 2eb94dd56a ("nvme: do not let the user delete a ctrl
before a complete") to the latest to avoid a potentially confusing merge
conflict.
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
We get a kernel crash about "list_add corruption. next->prev should be
prev (ffff9c801bc01210), but was ffff9c77b688237c.
(next=ffffae586d8afe68)."
crash> struct list_head 0xffff9c801bc01210
struct list_head {
next = 0xffffae586d8afe68,
prev = 0xffffae586d8afe68
}
crash> struct list_head 0xffff9c77b688237c
struct list_head {
next = 0x0,
prev = 0x0
}
crash> struct list_head 0xffffae586d8afe68
struct list_head struct: invalid kernel virtual address: ffffae586d8afe68 type: "gdb_readmem_callback"
Cannot access memory at address 0xffffae586d8afe68
[230469.019492] Call Trace:
[230469.032041] prepare_to_wait+0x8a/0xb0
[230469.044363] ? bch_btree_keys_free+0x6c/0xc0 [escache]
[230469.056533] mca_cannibalize_lock+0x72/0x90 [escache]
[230469.068788] mca_alloc+0x2ae/0x450 [escache]
[230469.080790] bch_btree_node_get+0x136/0x2d0 [escache]
[230469.092681] bch_btree_check_thread+0x1e1/0x260 [escache]
[230469.104382] ? finish_wait+0x80/0x80
[230469.115884] ? bch_btree_check_recurse+0x1a0/0x1a0 [escache]
[230469.127259] kthread+0x112/0x130
[230469.138448] ? kthread_flush_work_fn+0x10/0x10
[230469.149477] ret_from_fork+0x35/0x40
bch_btree_check_thread() and bch_dirty_init_thread() may call
mca_cannibalize() to cannibalize other cached btree nodes. Only one thread
can do it at a time, so the op of other threads will be added to the
btree_cache_wait list.
We must call finish_wait() to remove op from btree_cache_wait before free
it's memory address. Otherwise, the list will be damaged. Also should call
bch_cannibalize_unlock() to release the btree_cache_alloc_lock and wake_up
other waiters.
Fixes: 8e7102273f ("bcache: make bch_btree_check() to be multithreaded")
Fixes: b144e45fc5 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Cc: stable@vger.kernel.org
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-7-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In some specific situations, the return value of __bch_btree_node_alloc
may be NULL. This may lead to a potential NULL pointer dereference in
caller function like a calling chain :
btree_split->bch_btree_node_alloc->__bch_btree_node_alloc.
Fix it by initializing the return value in __bch_btree_node_alloc.
Fixes: cafe563591 ("bcache: A block layer cache")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 99d055b4fd ("block: remove per-disk debugfs files in
blk_unregister_queue") moves blk_trace_shutdown() from
blk_release_queue() to blk_unregister_queue(), this is safe if blktrace
is created through sysfs, however, there is a regression in corner
case.
blktrace can still be enabled after del_gendisk() through ioctl if
the disk is opened before del_gendisk(), and if blktrace is not shutdown
through ioctl before closing the disk, debugfs entries will be leaked.
Fix this problem by shutdown blktrace in disk_release(), this is safe
because blk_trace_remove() is reentrant.
Fixes: 99d055b4fd ("block: remove per-disk debugfs files in blk_unregister_queue")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230610022003.2557284-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
sg_ioctl() support to enable blktrace, which will create debugfs entries
"/sys/kernel/debug/block/sgx/", however, there is no guarantee that user
will remove these entries through ioctl, and deleting sg device doesn't
cleanup these blktrace entries.
This problem can be fixed by cleanup blktrace while releasing
request_queue, however, it's not a good idea to do this special handling
in common layer just for sg device.
Fix this problem by shutdown bltkrace in sg_device_destroy(), where the
device is deleted and all the users close the device, also grab a
scsi_device reference from sg_add_device() to prevent scsi_device to be
freed before sg_device_destroy();
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20230610022003.2557284-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
commit f168420c62 ("blk-mq: don't redirect completion for hctx withs
only one ctx mapping") When nvme applies a 1:1 mapping of hctx and ctx,
there will be no remote request.
But for ufs, the submission and completion queues could be asymmetric.
(e.g. Multiple SQs share one CQ) Therefore, 1:1 mapping of hctx and
ctx won't complete request on the submission cpu. In this situation,
this nr_ctx check could violate the QUEUE_FLAG_SAME_FORCE, as a result,
check on cpu id when there is only one ctx mapping.
Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
Signed-off-by: Po-Wen Kao <powen.kao@mediatek.com>
Suggested-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230614002529.6636-1-ed.tsai@mediatek.com
[axboe: fixed up indentation]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull MD updates from Song:
"The major changes are:
1. Protect md_thread with rcu, by Yu Kuai;
2. Various non-urgent raid5 and raid1/10 fixes, by Yu Kuai;
3. Non-urgent raid10 fixes, by Li Nan."
* tag 'md-next-20230613' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: (29 commits)
md/raid1-10: limit the number of plugged bio
md/raid1-10: don't handle pluged bio by daemon thread
md/md-bitmap: add a new helper to unplug bitmap asynchrously
md/raid1-10: submit write io directly if bitmap is not enabled
md/raid1-10: factor out a helper to submit normal write
md/raid1-10: factor out a helper to add bio to plug
md/raid10: prevent soft lockup while flush writes
md/raid10: fix io loss while replacement replace rdev
md/raid10: Do not add spare disk when recovery fails
md/raid10: clean up md_add_new_disk()
md/raid10: prioritize adding disk to 'removed' mirror
md/raid10: improve code of mrdev in raid10_sync_request
md/raid10: fix null-ptr-deref of mreplace in raid10_sync_request
md/raid5: don't start reshape when recovery or replace is in progress
md: protect md_thread with rcu
md/bitmap: factor out a helper to set timeout
md/bitmap: always wake up md_thread in timeout_store
dm-raid: remove useless checking in raid_message()
md: factor out a helper to wake up md_thread directly
md: fix duplicate filename for rdev
...
bio can be added to plug infinitely, and following writeback test can
trigger huge amount of plugged bio:
Test script:
modprobe brd rd_nr=4 rd_size=10485760
mdadm -CR /dev/md0 -l10 -n4 /dev/ram[0123] --assume-clean --bitmap=internal
echo 0 > /proc/sys/vm/dirty_background_ratio
fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 -iodepth=128 -name=test
Test result:
Monitor /sys/block/md0/inflight will found that inflight keep increasing
until fio finish writing, after running for about 2 minutes:
[root@fedora ~]# cat /sys/block/md0/inflight
0 4474191
Fix the problem by limiting the number of plugged bio based on the number
of copies for original bio.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-8-yukuai1@huaweicloud.com
current->bio_list will be set under submit_bio() context, in this case
bitmap io will be added to the list and wait for current io submission to
finish, while current io submission must wait for bitmap io to be done.
commit 874807a831 ("md/raid1{,0}: fix deadlock in bitmap_unplug.") fix
the deadlock by handling plugged bio by daemon thread.
On the one hand, the deadlock won't exist after commit a214b949d8
("blk-mq: only flush requests from the plug in blk_mq_submit_bio"). On
the other hand, current solution makes it impossible to flush plugged bio
in raid1/10_make_request(), because this will cause that all the writes
will goto daemon thread.
In order to limit the number of plugged bio, commit 874807a831
("md/raid1{,0}: fix deadlock in bitmap_unplug.") is reverted, and the
deadlock is fixed by handling bitmap io asynchronously.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-7-yukuai1@huaweicloud.com
If bitmap is enabled, bitmap must update before submitting write io, this
is why unplug callback must move these io to 'conf->pending_io_list' if
'current->bio_list' is not empty, which will suffer performance
degradation.
A new helper md_bitmap_unplug_async() is introduced to submit bitmap io
in a kworker, so that submit bitmap io in raid10_unplug() doesn't require
that 'current->bio_list' is empty.
This patch prepare to limit the number of plugged bio.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-6-yukuai1@huaweicloud.com
Commit 6cce3b23f6 ("[PATCH] md: write intent bitmap support for raid10")
add bitmap support, and it changed that write io is submitted through
daemon thread because bitmap need to be updated before write io. And
later, plug is used to fix performance regression because all the write io
will go to demon thread, which means io can't be issued concurrently.
However, if bitmap is not enabled, the write io should not go to daemon
thread in the first place, and plug is not needed as well.
Fixes: 6cce3b23f6 ("[PATCH] md: write intent bitmap support for raid10")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529131106.2123367-5-yukuai1@huaweicloud.com
