6.12-stable review patch. If anyone has any objections, please let me know.
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From: Su Yue glass.su@suse.com
commit 6130825f34d41718c98a9b1504a79a23e379701e upstream.
In clustermd, separate write-intent-bitmaps are used for each cluster node:
0 4k 8k 12k ------------------------------------------------------------------- | idle | md super | bm super [0] + bits | | bm bits[0, contd] | bm super[1] + bits | bm bits[1, contd] | | bm super[2] + bits | bm bits [2, contd] | bm super[3] + bits | | bm bits [3, contd] | | |
So in node 1, pg_index in __write_sb_page() could equal to bitmap->storage.file_pages. Then bitmap_limit will be calculated to 0. md_super_write() will be called with 0 size. That means the first 4k sb area of node 1 will never be updated through filemap_write_page(). This bug causes hang of mdadm/clustermd_tests/01r1_Grow_resize.
Here use (pg_index % bitmap->storage.file_pages) to make calculation of bitmap_limit correct.
Fixes: ab99a87542f1 ("md/md-bitmap: fix writing non bitmap pages") Signed-off-by: Su Yue glass.su@suse.com Reviewed-by: Heming Zhao heming.zhao@suse.com Link: https://lore.kernel.org/linux-raid/20250303033918.32136-1-glass.su@suse.com Signed-off-by: Yu Kuai yukuai3@huawei.com Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/md-bitmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -426,8 +426,8 @@ static int __write_sb_page(struct md_rde struct block_device *bdev; struct mddev *mddev = bitmap->mddev; struct bitmap_storage *store = &bitmap->storage; - unsigned int bitmap_limit = (bitmap->storage.file_pages - pg_index) << - PAGE_SHIFT; + unsigned long num_pages = bitmap->storage.file_pages; + unsigned int bitmap_limit = (num_pages - pg_index % num_pages) << PAGE_SHIFT; loff_t sboff, offset = mddev->bitmap_info.offset; sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE; unsigned int size = PAGE_SIZE; @@ -436,7 +436,7 @@ static int __write_sb_page(struct md_rde
bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev; /* we compare length (page numbers), not page offset. */ - if ((pg_index - store->sb_index) == store->file_pages - 1) { + if ((pg_index - store->sb_index) == num_pages - 1) { unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
if (last_page_size == 0)