git.armlinux.org.uk/linux.git - Linus' kernel tree

Age	Commit message (Collapse)	Author
2025-09-10	md/md-llbitmap: Use DIV_ROUND_UP_SECTOR_T	Nathan Chancellor
	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 <nathan@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-06	md/md-llbitmap: introduce new lockless bitmap	Yu Kuai
	Redundant data is used to enhance data fault tolerance, and the storage method for redundant data vary depending on the RAID levels. And it's important to maintain the consistency of redundant data. Bitmap is used to record which data blocks have been synchronized and which ones need to be resynchronized or recovered. Each bit in the bitmap represents a segment of data in the array. When a bit is set, it indicates that the multiple redundant copies of that data segment may not be consistent. Data synchronization can be performed based on the bitmap after power failure or readding a disk. If there is no bitmap, a full disk synchronization is required. Due to known performance issues with md-bitmap and the unreasonable implementations: - self-managed IO submitting like filemap_write_page(); - global spin_lock I have decided not to continue optimizing based on the current bitmap implementation, this new bitmap is invented without locking from IO fast path and can be used with fast disks. For designs and details, see the comments in drivers/md-llbitmap.c. Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-12-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Li Nan <linan122@huawei.com>