kernel/linux.git/drivers/md/persistent-data/dm-block-manager.c, branch v6.19.11

dm: Constify struct dm_block_validator

2024-07-19T10:08:15+00:00

'struct dm_block_validator' are not modified in these drivers. Constifying this structure moves some data to a read-only section, so increase overall security. On a x86_64, with allmodconfig, as an example: Before: ====== text data bss dec hex filename 32047 920 16 32983 80d7 drivers/md/dm-cache-metadata.o After: ===== text data bss dec hex filename 32075 896 16 32987 80db drivers/md/dm-cache-metadata.o Signed-off-by: Christophe JAILLET Signed-off-by: Mikulas Patocka

dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list

2024-02-20T19:22:55+00:00

Signed-off-by: Mike Snitzer

dm thin metadata: Fix ABBA deadlock by resetting dm_bufio_client

2023-06-16T22:24:13+00:00

As described in commit 8111964f1b85 ("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 8111964f1b85 ("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: 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata") Cc: stable@vger.kernel.org Signed-off-by: Li Lingfeng Signed-off-by: Mike Snitzer

dm: add missing empty lines

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm block-manager: avoid not required parentheses

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: correct block comments format.

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: change "unsigned" to "unsigned int"

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm: add missing SPDX-License-Indentifiers

2023-02-14T19:23:06+00:00

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm bufio: Add flags argument to dm_bufio_client_create

2022-07-28T21:46:14+00:00

Add a flags argument to dm_bufio_client_create and update all the callers. This is in preparation to add the DM_BUFIO_NO_SLEEP flag. Signed-off-by: Nathan Huckleberry Signed-off-by: Mike Snitzer

dm thin metadata: Fix use-after-free in dm_bm_set_read_only

2020-09-02T17:38:40+00:00

The following error ocurred when testing disk online/offline: [ 301.798344] device-mapper: thin: 253:5: aborting current metadata transaction [ 301.848441] device-mapper: thin: 253:5: failed to abort metadata transaction [ 301.849206] Aborting journal on device dm-26-8. [ 301.850489] EXT4-fs error (device dm-26) in __ext4_new_inode:943: Journal has aborted [ 301.851095] EXT4-fs (dm-26): Delayed block allocation failed for inode 398742 at logical offset 181 with max blocks 19 with error 30 [ 301.854476] BUG: KASAN: use-after-free in dm_bm_set_read_only+0x3a/0x40 [dm_persistent_data] Reason is: metadata_operation_failed abort_transaction dm_pool_abort_metadata __create_persistent_data_objects r = __open_or_format_metadata if (r) --> If failed will free pmd->bm but pmd->bm not set NULL dm_block_manager_destroy(pmd->bm); set_pool_mode dm_pool_metadata_read_only(pool->pmd); dm_bm_set_read_only(pmd->bm); --> use-after-free Add checks to see if pmd->bm is NULL in dm_bm_set_read_only and dm_bm_set_read_write functions. If bm is NULL it means creating the bm failed and so dm_bm_is_read_only must return true. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer