From 55252ab72b774119afedfdc6d1f142ffa2a9b818 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Sun, 22 Sep 2019 02:43:55 +0800 Subject: [PATCH] erofs: fix erofs_get_meta_page locking due to a cleanup 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/20190904020912.63925-26-gaoxiang25@huawei.com Fixes: 618f40ea026b ("erofs: use read_cache_page_gfp for erofs_get_meta_page") Reviewed-by: Chao Yu Link: https://lore.kernel.org/r/20190921184355.149928-1-gaoxiang25@huawei.com Signed-off-by: Gao Xiang --- 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,