kernel/linux.git/drivers/md/md-llbitmap.c, branch v7.1-rc5

md/md-bitmap: split bitmap sysfs groups

2026-04-28T12:44:37+00:00

Split the classic bitmap sysfs files into a common bitmap group with the location attribute and a separate internal bitmap group for the remaining files. At the same time, convert bitmap operations from a single sysfs group to a sysfs group array so backends can share part of their sysfs layout while adding backend-specific attributes separately. Switch the bitmap sysfs helpers to use sysfs_update_groups() for the add and update path, and remove groups in reverse order so shared named groups are unmerged before the last group removes the directory. Also make bitmap operation lookup depend only on the currently selected bitmap id matching the installed backend. This prepares the lookup path for a later registered none backend. Reviewed-by: Su Yue Link: https://lore.kernel.org/r/20260425024615.1696892-3-yukuai@fnnas.com Signed-off-by: Yu Kuai

md/md-llbitmap: optimize initial sync with write_zeroes_unmap support

2026-04-07T05:09:22+00:00

For RAID-456 arrays with llbitmap, if all underlying disks support write_zeroes with unmap, issue write_zeroes to zero all disk data regions and initialize the bitmap to BitCleanUnwritten instead of BitUnwritten. This optimization skips the initial XOR parity building because: 1. write_zeroes with unmap guarantees zeroed reads after the operation 2. For RAID-456, when all data is zero, parity is automatically consistent (0 XOR 0 XOR ... = 0) 3. BitCleanUnwritten indicates parity is valid but no user data has been written The implementation adds two helper functions: - llbitmap_all_disks_support_wzeroes_unmap(): Checks if all active disks support write_zeroes with unmap - llbitmap_zero_all_disks(): Issues blkdev_issue_zeroout() to each rdev's data region to zero all disks The zeroing and bitmap state setting happens in llbitmap_init_state() during bitmap initialization. If any disk fails to zero, we fall back to BitUnwritten and normal lazy recovery. This significantly reduces array initialization time for RAID-456 arrays built on modern NVMe SSDs or other devices that support write_zeroes with unmap. Reviewed-by: Xiao Ni Link: https://lore.kernel.org/linux-raid/20260323054644.3351791-4-yukuai@fnnas.com/ Signed-off-by: Yu Kuai

md/md-llbitmap: add CleanUnwritten state for RAID-5 proactive parity building

2026-04-07T05:09:22+00:00

Add new states to the llbitmap state machine to support proactive XOR parity building for RAID-5 arrays. This allows users to pre-build parity data for unwritten regions before any user data is written. New states added: - BitNeedSyncUnwritten: Transitional state when proactive sync is triggered via sysfs on Unwritten regions. - BitSyncingUnwritten: Proactive sync in progress for unwritten region. - BitCleanUnwritten: XOR parity has been pre-built, but no user data written yet. When user writes to this region, it transitions to BitDirty. New actions added: - BitmapActionProactiveSync: Trigger for proactive XOR parity building. - BitmapActionClearUnwritten: Convert CleanUnwritten/NeedSyncUnwritten/ SyncingUnwritten states back to Unwritten before recovery starts. State flows: - Current (lazy): Unwritten -> (write) -> NeedSync -> (sync) -> Dirty -> Clean - New (proactive): Unwritten -> (sysfs) -> NeedSyncUnwritten -> (sync) -> CleanUnwritten - On write to CleanUnwritten: CleanUnwritten -> (write) -> Dirty -> Clean - On disk replacement: CleanUnwritten regions are converted to Unwritten before recovery starts, so recovery only rebuilds regions with user data A new sysfs interface is added at /sys/block/mdX/md/llbitmap/proactive_sync (write-only) to trigger proactive sync. This only works for RAID-456 arrays. Link: https://lore.kernel.org/linux-raid/20260323054644.3351791-3-yukuai@fnnas.com/ Signed-off-by: Yu Kuai

md/md-llbitmap: raise barrier before state machine transition

2026-03-15T17:24:59+00:00

Move the barrier raise operation before calling llbitmap_state_machine() in both llbitmap_start_write() and llbitmap_start_discard(). This ensures the barrier is in place before any state transitions occur, preventing potential race conditions where the state machine could complete before the barrier is properly raised. Cc: stable@vger.kernel.org Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Link: https://lore.kernel.org/linux-raid/20260223024038.3084853-3-yukuai@fnnas.com Signed-off-by: Yu Kuai

md/md-llbitmap: skip reading rdevs that are not in_sync

2026-03-15T17:24:59+00:00

When reading bitmap pages from member disks, the code iterates through all rdevs and attempts to read from the first available one. However, it only checks for raid_disk assignment and Faulty flag, missing the In_sync flag check. This can cause bitmap data to be read from spare disks that are still being rebuilt and don't have valid bitmap information yet. Reading stale or uninitialized bitmap data from such disks can lead to incorrect dirty bit tracking, potentially causing data corruption during recovery or normal operation. Add the In_sync flag check to ensure bitmap pages are only read from fully synchronized member disks that have valid bitmap data. Cc: stable@vger.kernel.org Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Link: https://lore.kernel.org/linux-raid/20260223024038.3084853-2-yukuai@fnnas.com Signed-off-by: Yu Kuai

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

md/md-llbitmap: fix percpu_ref not resurrected on suspend timeout

2026-01-26T05:25:31+00:00

When llbitmap_suspend_timeout() times out waiting for percpu_ref to become zero, it returns -ETIMEDOUT without resurrecting the percpu_ref. The caller (md_llbitmap_daemon_fn) then continues to the next page without calling llbitmap_resume(), leaving the percpu_ref in a killed state permanently. Fix this by resurrecting the percpu_ref before returning the error, ensuring the page control structure remains usable for subsequent operations. Link: https://lore.kernel.org/linux-raid/20260123182623.3718551-3-yukuai@fnnas.com Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Signed-off-by: Yu Kuai Reviewed-by: Li Nan

md/md-llbitmap: Remove unneeded semicolon

2025-11-08T08:55:35+00:00

Remove unnecessary semicolons reported by Coccinelle/coccicheck and the semantic patch at scripts/coccinelle/misc/semicolon.cocci. Link: https://lore.kernel.org/linux-raid/20250910091912.25624-1-nichen@iscas.ac.cn Signed-off-by: Chen Ni Signed-off-by: Yu Kuai

md/md-llbitmap: Use DIV_ROUND_UP_SECTOR_T

2025-09-11T00:18:41+00:00

When building for 32-bit platforms, there are several link (if builtin) or modpost (if a module) errors due to dividends of type 'sector_t' in DIV_ROUND_UP: arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_resize': drivers/md/md-llbitmap.c:1017:(.text+0xae8): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.c:1020:(.text+0xb10): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_end_discard': drivers/md/md-llbitmap.c:1114:(.text+0xf14): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_start_discard': drivers/md/md-llbitmap.c:1097:(.text+0x1808): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o: in function `llbitmap_read_sb': drivers/md/md-llbitmap.c:867:(.text+0x2080): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: drivers/md/md-llbitmap.o:drivers/md/md-llbitmap.c:895: more undefined references to `__aeabi_uldivmod' follow Use DIV_ROUND_UP_SECTOR_T instead of DIV_ROUND_UP, which exists to handle this exact situation. Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap") Signed-off-by: Nathan Chancellor Signed-off-by: Jens Axboe