kernel/linux.git/drivers/md/md-bitmap.c, branch v7.0-rc7

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/bitmap: fix GPF in write_page caused by resize race

2026-01-26T05:36:06+00:00

A General Protection Fault occurs in write_page() during array resize: RIP: 0010:write_page+0x22b/0x3c0 [md_mod] This is a use-after-free race between bitmap_daemon_work() and __bitmap_resize(). The daemon iterates over `bitmap->storage.filemap` without locking, while the resize path frees that storage via md_bitmap_file_unmap(). `quiesce()` does not stop the md thread, allowing concurrent access to freed pages. Fix by holding `mddev->bitmap_info.mutex` during the bitmap update. Link: https://lore.kernel.org/linux-raid/20260120102456.25169-1-jinpu.wang@ionos.com Closes: https://lore.kernel.org/linux-raid/CAMGffE=Mbfp=7xD_hYxXk1PAaCZNSEAVeQGKGy7YF9f2S4=NEA@mail.gmail.com/T/#u Cc: stable@vger.kernel.org Fixes: d60b479d177a ("md/bitmap: add bitmap_resize function to allow bitmap resizing.") Signed-off-by: Jack Wang Signed-off-by: Yu Kuai

md: merge mddev serialize_policy into mddev_flags

2026-01-26T05:10:51+00:00

There is not need to use a separate field in struct mddev, there are no functional changes. Link: https://lore.kernel.org/linux-raid/20260114171241.3043364-5-yukuai@fnnas.com Signed-off-by: Yu Kuai Reviewed-by: Li Nan

md/md-llbitmap: introduce new lockless bitmap

2025-09-06T09:27:51+00:00

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 Reviewed-by: Li Nan

md/md-bitmap: support discard for bitmap ops

2025-09-06T09:18:19+00:00

Use two new methods {start, end}_discard in bitmap_ops and a new field 'rw' in struct md_io_clone to handle discard IO, prepare to support new md bitmap. Since all bitmap functions to hanlde write IO are the same, also add typedef to make code cleaner. Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-4-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni Reviewed-by: Hannes Reinecke Reviewed-by: Li Nan

md: add a new parameter 'offset' to md_super_write()

2025-09-06T09:17:26+00:00

The parameter is always set to 0 for now, following patches will use this helper to write llbitmap to underlying disks, allow writing dirty sectors instead of the whole page. Also rename md_super_write to md_write_metadata since there is nothing super-block specific. Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-2-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Li Nan

md/md-bitmap: introduce CONFIG_MD_BITMAP

2025-09-06T09:12:22+00:00

Now that all implementations are internal, it's sensible to add a config option for md-bitmap, and it's a good way for isolation. Link: https://lore.kernel.org/linux-raid/20250707012711.376844-16-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni

md/raid1: check bitmap before behind write

2025-09-06T09:11:58+00:00

behind write rely on bitmap, because the number of IO are recorded in bitmap->behind_writes, and callers rely on bitmap_wait_behind_writes() to wait for IO to be done. However, currently callers doesn't check if bitmap is enabeld before calling into behind methods. Hence if behind write start without bitmap, readers will not wait for slow write IO to be done and old data can be read in some corner cases. Link: https://lore.kernel.org/linux-raid/20250707012711.376844-10-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni

md/md-bitmap: handle the case bitmap is not enabled before end_sync()

2025-09-06T09:11:54+00:00

This case can be handled without knowing internal implementation. Prepare to introduce CONFIG_MD_BITMAP. Link: https://lore.kernel.org/linux-raid/20250707012711.376844-9-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Xiao Ni