kernel/linux.git/drivers/md/md-bitmap.c, branch v7.2-rc1

md/raid1: honor REQ_NOWAIT when waiting for behind writes

2026-06-20T20:19:27+00:00

raid1 supports REQ_NOWAIT reads by avoiding waits in the barrier path through wait_read_barrier(). However, a read can still block on a WriteMostly device when the array uses a bitmap and there are outstanding behind writes. In that case raid1 unconditionally calls wait_behind_writes(), which may sleep until all behind writes complete. As a result, a REQ_NOWAIT read can block despite the caller explicitly requesting non-blocking behavior. This ensures that raid1 consistently honors REQ_NOWAIT reads across all paths that may otherwise wait for behind writes. Fixes: 5aa705039c4f ("md: raid1 add nowait support") Signed-off-by: Abd-Alrhman Masalkhi Link: https://patch.msgid.link/20260611083514.754922-1-abd.masalkhi@gmail.com Signed-off-by: Yu Kuai

Merge tag 'vfs-7.2-rc1.bh' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-06-14T22:06:08+00:00

Pull buffer_head updates from Christian Brauner: "This removes b_end_io from struct buffer_head. Instead of setting bio->bi_end_io to end_bio_bh_io_sync() which then calls bh->b_end_io(), the new bh_submit() and __bh_submit() interfaces set bio->bi_end_io to the appropriate completion handler directly, replacing two indirect function calls in the completion path with one. It is also one fewer function pointer in the middle of a writable data structure that can be corrupted, it shrinks struct buffer_head from 104 to 96 bytes allowing roughly 7% more buffer_heads to be cached in the same amount of memory, and it removes some atomic operations as the buffer refcount is no longer incremented before calling the end_io handler. All in-tree users (fs/buffer.c itself, ext4, jbd2, ocfs2, gfs2, nilfs2, and md-bitmap) are converted, and submit_bh(), mark_buffer_async_write(), and end_buffer_write_sync() are removed" * tag 'vfs-7.2-rc1.bh' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (34 commits) buffer: Remove end_buffer_write_sync() buffer: Change calling convention for end_buffer_read_sync() buffer: Remove b_end_io buffer: Remove submit_bh() md-bitmap: Convert read_file_page and write_file_page to bh_submit() nilfs2: Convert nilfs_mdt_submit_block to bh_submit() nilfs2: Convert nilfs_gccache_submit_read_data to bh_submit() nilfs2: Convert nilfs_btnode_submit_block to bh_submit() buffer: Remove mark_buffer_async_write() gfs2: Convert gfs2_aspace_write_folio to bh_submit() gfs2: Remove use of b_end_io in gfs2_meta_read_endio() gfs2: Convert gfs2_dir_readahead to bh_submit() gfs2: Convert gfs2_metapath_ra to bh_submit() ocfs2: Convert ocfs2_write_super_or_backup to bh_submit() ocfs2: Convert ocfs2_read_blocks to bh_submit() ocfs2: Convert ocfs2_read_block to bh_submit() ocfs2: Convert ocfs2_write_block to bh_submit() jbd2: Convert jbd2_write_superblock() to bh_submit() jbd2: Convert journal commit to bh_submit() ext4: Convert ext4_commit_super() to bh_submit() ...

md-bitmap: Convert read_file_page and write_file_page to bh_submit()

2026-06-04T08:28:10+00:00

Avoid an extra indirect function call by using bh_submit() instead of submit_bh(). Signed-off-by: Matthew Wilcox (Oracle) Link: https://patch.msgid.link/20260528173150.1093780-31-willy@infradead.org Reviewed-by: Jan Kara Cc: linux-raid@vger.kernel.org Signed-off-by: Christian Brauner (Amutable)

md/md-bitmap: add a none backend for bitmap grow

2026-04-28T12:44:38+00:00

Add a real none bitmap backend that exposes the common bitmap sysfs group and use it to keep bitmap/location available when an array has no bitmap. Then switch the bitmap location sysfs path to move only between none and the classic bitmap backend, using the no-sysfs bitmap helpers while merging or unmerging the internal bitmap sysfs group. This restores mdadm --grow bitmap addition through bitmap/location. Fixes: fb8cc3b0d9db ("md/md-bitmap: delay registration of bitmap_ops until creating bitmap") Reviewed-by: Su Yue Link: https://lore.kernel.org/r/20260425024615.1696892-4-yukuai@fnnas.com Signed-off-by: Yu Kuai

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

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