linux/drivers/md
Ming-Hung Tsai 71f4123cf2 dm array: fix cursor index when skipping across block boundaries
[ Upstream commit 0bb1968da2 ]

dm_array_cursor_skip() seeks to the target position by loading array
blocks iteratively until the specified number of entries to skip is
reached. When seeking across block boundaries, it uses
dm_array_cursor_next() to step into the next block.
dm_array_cursor_skip() must first move the cursor index to the end
of the current block; otherwise, the cursor position could incorrectly
remain in the same block, causing the actual number of skipped entries
to be much smaller than expected.

This bug affects cache resizing in v2 metadata and could lead to data
loss if the fast device is shrunk during the first-time resume. For
example:

1. create a cache metadata consists of 32768 blocks, with a dirty block
   assigned to the second bitmap block. cache_restore v1.0 is required.

cat <<EOF >> cmeta.xml
<superblock uuid="" block_size="64" nr_cache_blocks="32768" \
policy="smq" hint_width="4">
  <mappings>
    <mapping cache_block="32767" origin_block="0" dirty="true"/>
  </mappings>
</superblock>
EOF
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2

2. bring up the cache while attempt to discard all the blocks belonging
   to the second bitmap block (block# 32576 to 32767). The last command
   is expected to fail, but it actually succeeds.

dmsetup create cdata --table "0 2084864 linear /dev/sdc 8192"
dmsetup create corig --table "0 65536 linear /dev/sdc 2105344"
dmsetup create cache --table "0 65536 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 64 2 metadata2 writeback smq \
2 migration_threshold 0"

In addition to the reproducer described above, this fix can be
verified using the "array_cursor/skip" tests in dm-unit:
  dm-unit run /pdata/array_cursor/skip/ --kernel-dir <KERNEL_DIR>

Signed-off-by: Ming-Hung Tsai <mtsai@redhat.com>
Fixes: 9b696229aa ("dm persistent data: add cursor skip functions to the cursor APIs")
Reviewed-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-01-17 13:36:10 +01:00
..
bcache bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again 2024-12-14 19:59:55 +01:00
persistent-data dm array: fix cursor index when skipping across block boundaries 2025-01-17 13:36:10 +01:00
dm-audit.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-audit.h dm: introduce audit event module for device mapper 2021-10-27 16:53:47 -04:00
dm-bio-prison-v1.c dm: improve hash_locks sizing and hash function 2023-03-30 15:57:51 -04:00
dm-bio-prison-v1.h dm bio prison v1: add dm_cell_key_has_valid_range 2023-03-30 15:57:51 -04:00
dm-bio-prison-v2.c dm: address space issues relative to switch/while/for/... 2023-02-14 14:23:06 -05:00
dm-bio-prison-v2.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-bio-record.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-bufio.c dm-bufio: fix warnings about duplicate slab caches 2024-12-09 10:32:41 +01:00
dm-builtin.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-cache-background-tracker.c dm-cache: fix warnings about duplicate slab caches 2024-12-09 10:32:40 +01:00
dm-cache-background-tracker.h dm-cache: fix warnings about duplicate slab caches 2024-12-09 10:32:40 +01:00
dm-cache-block-types.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-cache-metadata.c Revert "mm: shrinkers: convert shrinker_rwsem to mutex" 2023-06-19 13:19:33 -07:00
dm-cache-metadata.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy-internal.h dm: add missing empty lines 2023-02-14 14:23:06 -05:00
dm-cache-policy-smq.c dm cache policy smq: ensure IO doesn't prevent cleaner policy progress 2023-07-25 11:55:50 -04:00
dm-cache-policy.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy.h dm: address indent/space issues 2023-02-14 14:23:06 -05:00
dm-cache-target.c dm-cache: fix warnings about duplicate slab caches 2024-12-09 10:32:40 +01:00
dm-clone-metadata.c bitmap: introduce generic optimized bitmap_size() 2024-08-29 17:33:14 +02:00
dm-clone-metadata.h dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions() 2020-03-27 14:42:51 -04:00
dm-clone-target.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
dm-core.h dm: limit the number of targets and parameter size area 2024-02-23 09:25:27 +01:00
dm-crypt.c dm-verity, dm-crypt: align "struct bvec_iter" correctly 2024-03-26 18:19:12 -04:00
dm-delay.c dm-delay: fix a race between delay_presuspend and delay_bio 2023-12-03 07:33:09 +01:00
dm-dust.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-ebs-target.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-era-target.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
dm-exception-store.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-exception-store.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-flakey.c dm flakey: introduce random_read_corrupt and random_write_corrupt options 2023-06-16 18:24:13 -04:00
dm-ima.c dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-ima.h dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-init.c dm init: Handle minors larger than 255 2024-09-12 11:11:35 +02:00
dm-integrity.c dm-integrity: fix a race condition when accessing recalc_sector 2024-09-18 19:24:07 +02:00
dm-io-rewind.c dm: avoid void function return statements 2023-02-14 14:23:07 -05:00
dm-io-tracker.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-io.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-ioctl.c dm resume: don't return EINVAL when signalled 2024-08-29 17:33:13 +02:00
dm-kcopyd.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-linear.c dm: remove unnecessary (void*) conversions 2023-04-11 12:01:01 -04:00
dm-log-userspace-base.c dm: avoid void function return statements 2023-02-14 14:23:07 -05:00
dm-log-userspace-transfer.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-log-userspace-transfer.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-log-writes.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-log.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-mpath.c dm: push error reporting down to dm_register_target() 2023-04-11 12:01:01 -04:00
dm-mpath.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-path-selector.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-path-selector.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-historical-service-time.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-ps-io-affinity.c dm: address space issues relative to switch/while/for/... 2023-02-14 14:23:06 -05:00
dm-ps-queue-length.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-round-robin.c dm: correct block comments format. 2023-02-14 14:23:06 -05:00
dm-ps-service-time.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-raid.c dm-raid: fix lockdep waring in "pers->hot_add_disk" 2024-04-03 15:28:26 +02:00
dm-raid1.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-region-hash.c dm: correct block comments format. 2023-02-14 14:23:06 -05:00
dm-rq.c Revert "dm: requeue IO if mapping table not yet available" 2024-10-04 16:29:40 +02:00
dm-rq.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-snap-persistent.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-snap-transient.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-snap.c dm snapshot: fix lockup in dm_exception_table_exit 2024-04-03 15:28:37 +02:00
dm-stats.c dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stats.h dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stripe.c dm: remove unnecessary (void*) conversions 2023-04-11 12:01:01 -04:00
dm-switch.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-sysfs.c dm sysfs: make kobj_type structure constant 2023-02-14 14:23:08 -05:00
dm-table.c dm: limit the number of targets and parameter size area 2024-02-23 09:25:27 +01:00
dm-target.c dm: push error reporting down to dm_register_target() 2023-04-11 12:01:01 -04:00
dm-thin-metadata.c - Update DM crypt to allocate compound pages if possible. 2023-06-30 12:16:00 -07:00
dm-thin-metadata.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-thin.c dm thin: Add missing destroy_work_on_stack() 2024-12-09 10:33:08 +01:00
dm-uevent.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-uevent.h dm: fix undue/missing spaces 2023-02-14 14:23:06 -05:00
dm-unstripe.c dm-unstriped: cast an operand to sector_t to prevent potential uint32_t overflow 2024-11-14 13:19:37 +01:00
dm-verity-fec.c dm-verity: align struct dm_verity_fec_io properly 2023-12-08 08:52:16 +01:00
dm-verity-fec.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-verity-loadpin.c dm: verity-loadpin: Add NULL pointer check for 'bdev' parameter 2023-06-28 10:43:04 -07:00
dm-verity-target.c Revert: "dm-verity: restart or panic on an I/O error" 2024-10-04 16:30:05 +02:00
dm-verity-verify-sig.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity-verify-sig.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity.h dm-verity, dm-crypt: align "struct bvec_iter" correctly 2024-03-26 18:19:12 -04:00
dm-writecache.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-zero.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-zone.c dm zone: Use the bitmap API to allocate bitmaps 2023-06-16 18:24:13 -04:00
dm-zoned-metadata.c dm: dm-zoned: use __bio_add_page for adding single metadata page 2023-05-31 09:50:02 -06:00
dm-zoned-reclaim.c dm kcopyd: avoid useless atomic operations 2021-06-04 12:07:24 -04:00
dm-zoned-target.c dm zoned: free dmz->ddev array in dmz_put_zoned_devices 2023-09-20 13:48:06 -04:00
dm-zoned.h dm/dm-zoned: Use the enum req_op type 2022-07-14 12:14:31 -06:00
dm.c Revert "dm: requeue IO if mapping table not yet available" 2024-10-04 16:29:40 +02:00
dm.h dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.h 2023-06-16 18:24:14 -04:00
Kconfig dm audit: fix Kconfig so DM_AUDIT depends on BLK_DEV_DM 2024-01-20 11:51:45 +01:00
Makefile hardening updates for v5.20-rc1 2022-08-02 14:38:59 -07:00
md-autodetect.c init: improve the name_to_dev_t interface 2023-06-05 10:56:46 -06:00
md-bitmap.c md/md-bitmap: Add missing destroy_work_on_stack() 2024-12-09 10:33:01 +01:00
md-bitmap.h md-bitmap: don't use ->index for pages backing the bitmap file 2023-07-27 00:13:29 -07:00
md-cluster.c md: Hold mddev->reconfig_mutex when trying to get mddev->sync_thread 2023-08-15 09:40:26 -07:00
md-cluster.h md-cluster: introduce resync_info_get interface for sanity check 2018-10-18 09:36:35 -07:00
md-faulty.c md/md-faulty: enable io accounting 2023-07-27 00:13:30 -07:00
md-linear.c md/md-linear: enable io accounting 2023-07-27 00:13:30 -07:00
md-linear.h md/raid1: Replace zero-length array with flexible-array 2020-05-13 12:02:23 -07:00
md-multipath.c md/md-multipath: enable io accounting 2023-07-27 00:13:29 -07:00
md-multipath.h md: convert to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
md.c md: clean up invalid BUG_ON in md_ioctl 2024-08-29 17:33:35 +02:00
md.h md: fix warning for holder mismatch from export_rdev() 2023-09-08 13:16:40 -07:00
raid0.c md: raid0: account for split bio in iostat accounting 2023-08-17 21:11:31 -07:00
raid0.h md/raid0: add discard support for the 'original' layout 2023-06-30 15:43:50 -07:00
raid1-10.c md/raid1-10: fix casting from randomized structure in raid1_submit_write() 2023-06-23 09:33:16 -07:00
raid1.c raid1: fix use-after-free for original bio in raid1_write_request() 2024-04-17 11:19:25 +02:00
raid1.h md/raid1: switch to use md_account_bio() for io accounting 2023-07-27 00:13:29 -07:00
raid5-cache.c md/raid5-cache: use READ_ONCE/WRITE_ONCE for 'conf->log' 2024-08-29 17:33:27 +02:00
raid5-log.h md/raid5-ppl: Drop unused argument from ppl_handle_flush_request() 2022-08-02 17:14:31 -06:00
raid5-ppl.c md: raid5: use __bio_add_page to add single page to new bio 2023-05-31 09:50:02 -06:00
raid5.c md/raid5: avoid BUG_ON() while continue reshape after reassembling 2024-08-14 13:58:41 +02:00
raid5.h hardening updates for v6.5-rc1 2023-06-27 21:24:18 -07:00
raid10.c md: Hold mddev->reconfig_mutex when trying to get mddev->sync_thread 2023-08-15 09:40:26 -07:00
raid10.h md/raid10: switch to use md_account_bio() for io accounting 2023-07-27 00:13:29 -07:00