kernel/linux.git/drivers/md/dm-thin.c, branch v6.19.11

dm: ignore discard return value

2025-12-10T18:28:22+00:00

__blkdev_issue_discard() always returns 0, making all error checking at call sites dead code. For dm-thin change issue_discard() return type to void, in passdown_double_checking_shared_status() remove the r assignment from return value of the issue_discard(), for end_discard() hardcode value of r to 0 that matches only value returned from __blkdev_issue_discard(). Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Chaitanya Kulkarni Signed-off-by: Mikulas Patocka

dm: Fix deadlock when reloading a multipath table

2025-10-20T13:26:57+00:00

Request-based devices (dm-multipath) queue I/O in blk-mq on noflush suspends. Any queued IO will make it impossible to freeze the queue. If a process attempts to update the queue limits while there is queued IO, it can be get stuck holding the limits lock, while unable to freeze the queue. If device-mapper then attempts to update the limits during a table swap, it will deadlock trying to grab the limits lock while making it impossible to flush the IO. Disallow updating the queue limits during a table swap, when updating an immutable request-based dm device (dm-multipath) during a noflush suspend. It is userspace's responsibility to make sure that the new table uses the same limits as the existing table if it asks for a noflush suspend. Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka

dm: use vmalloc_array() to simplify code

2025-08-19T09:12:50+00:00

Remove array_size() calls and replace vmalloc() with vmalloc_array() to simplify the code. Signed-off-by: Qianfeng Rong Signed-off-by: Mikulas Patocka

dm: set DM_TARGET_PASSES_CRYPTO feature for dm-thin

2025-07-31T14:30:02+00:00

dm-thin obviously can pass through inline crypto support. Signed-off-by: LongPing Wei Signed-off-by: Mikulas Patocka

Merge tag 'for-6.13/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2025-01-08T18:12:01+00:00

Pull device mapper fixes from Mikulas Patocka: - dm-array fixes - dm-verity forward error correction fixes - remove the flag DM_TARGET_PASSES_INTEGRITY from dm-ebs - dm-thin RCU list fix * tag 'for-6.13/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm thin: make get_first_thin use rcu-safe list first function dm-ebs: don't set the flag DM_TARGET_PASSES_INTEGRITY dm-verity FEC: Avoid copying RS parity bytes twice. dm-verity FEC: Fix RS FEC repair for roots unaligned to block size (take 2) dm array: fix cursor index when skipping across block boundaries dm array: fix unreleased btree blocks on closing a faulty array cursor dm array: fix releasing a faulty array block twice in dm_array_cursor_end

dm thin: make get_first_thin use rcu-safe list first function

2025-01-08T14:29:39+00:00

The documentation in rculist.h explains the absence of list_empty_rcu() and cautions programmers against relying on a list_empty() -> list_first() sequence in RCU safe code. This is because each of these functions performs its own READ_ONCE() of the list head. This can lead to a situation where the list_empty() sees a valid list entry, but the subsequent list_first() sees a different view of list head state after a modification. In the case of dm-thin, this author had a production box crash from a GP fault in the process_deferred_bios path. This function saw a valid list head in get_first_thin() but when it subsequently dereferenced that and turned it into a thin_c, it got the inside of the struct pool, since the list was now empty and referring to itself. The kernel on which this occurred printed both a warning about a refcount_t being saturated, and a UBSAN error for an out-of-bounds cpuid access in the queued spinlock, prior to the fault itself. When the resulting kdump was examined, it was possible to see another thread patiently waiting in thin_dtr's synchronize_rcu. The thin_dtr call managed to pull the thin_c out of the active thins list (and have it be the last entry in the active_thins list) at just the wrong moment which lead to this crash. Fortunately, the fix here is straight forward. Switch get_first_thin() function to use list_first_or_null_rcu() which performs just a single READ_ONCE() and returns NULL if the list is already empty. This was run against the devicemapper test suite's thin-provisioning suites for delete and suspend and no regressions were observed. Signed-off-by: Krister Johansen Fixes: b10ebd34ccca ("dm thin: fix rcu_read_lock being held in code that can sleep") Cc: stable@vger.kernel.org Acked-by: Ming-Hung Tsai Signed-off-by: Mikulas Patocka

Merge tag 'for-6.13/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2024-11-26T02:54:00+00:00

Pull device mapper updates from Mikulas Patocka: - remove unused functions and variables - rate-limit error messages in syslog - fix typo - remove u64 alignment requirement for murmurhash - reset bi_ioprio to the default for dm-vdo - add support for get_unique_id - Add missing destroy_work_on_stack() to dm-thin - use kmalloc to allocate power-of-two sized buffers in bufio * tag 'for-6.13/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm-verity: remove the unused "data_start" variable dm-bufio: use kmalloc to allocate power-of-two sized buffers dm thin: Add missing destroy_work_on_stack() dm: add support for get_unique_id dm vdo: fix function doc comment formatting dm vdo int-map: remove unused parameters dm-vdo: reset bi_ioprio to the default value when the bio is reset dm-vdo murmurhash: remove u64 alignment requirement dm: Fix typo in error message dm ioctl: rate limit a couple of ioctl based error messages dm vdo: Remove unused uds_compute_index_size dm vdo: Remove unused functions dm: zoned: Remove unused functions dm: Remove unused dm_table_bio_based dm: Remove unused dm_set_md_type dm cache: Remove unused functions in bio-prison-v1 dm cache: Remove unused dm_cache_size dm cache: Remove unused dm_cache_dump dm cache: Remove unused btracker_nr_writebacks_queued

dm thin: Add missing destroy_work_on_stack()

2024-11-20T10:38:05+00:00

This commit add missed destroy_work_on_stack() operations for pw->worker in pool_work_wait(). Fixes: e7a3e871d895 ("dm thin: cleanup noflush_work to use a proper completion") Cc: stable@vger.kernel.org Signed-off-by: Yuan Can Signed-off-by: Mikulas Patocka

block: add a bdev_limits helper

2024-10-29T15:15:00+00:00

Add a helper to get the queue_limits from the bdev without having to poke into the request_queue. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de Signed-off-by: Jens Axboe

dm: Convert to use ERR_CAST()

2024-09-02T09:41:11+00:00

Use ERR_CAST() as it is designed for casting an error pointer to another type. This macro utilizes the __force and __must_check modifiers, which instruct the compiler to verify for errors at the locations where it is employed. Signed-off-by: Yuesong Li Signed-off-by: Mikulas Patocka