After doing more drop_caches stress test on our products, I found the mistake introduced by a very recent cleanup [1].
The current rule is that "erofs_get_meta_page" should be returned with page locked (although it's mostly unnecessary for read-only fs after pages are PG_uptodate), but a fix should be done for this. [1] https://lore.kernel.org/r/[email protected] Fixes: 618f40ea026b ("erofs: use read_cache_page_gfp for erofs_get_meta_page") Signed-off-by: Gao Xiang <[email protected]> --- changelog from v1: - type of return value should be struct page *. fs/erofs/data.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 8a9fcbd0e8ac..fc3a8d8064f8 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -34,11 +34,15 @@ static void erofs_readendio(struct bio *bio) struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr) { - struct inode *const bd_inode = sb->s_bdev->bd_inode; - struct address_space *const mapping = bd_inode->i_mapping; + struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping; + struct page *page; - return read_cache_page_gfp(mapping, blkaddr, + page = read_cache_page_gfp(mapping, blkaddr, mapping_gfp_constraint(mapping, ~__GFP_FS)); + /* should already be PageUptodate */ + if (!IS_ERR(page)) + lock_page(page); + return page; } static int erofs_map_blocks_flatmode(struct inode *inode, -- 2.17.1
