From c72db71ed61ff51c2b8189ac9889dd18f22eb612 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 12 Jul 2019 16:55:42 +0800 Subject: f2fs: fix panic of IO alignment feature Since 07173c3ec276 ("block: enable multipage bvecs"), one bio vector can store multi pages, so that we can not calculate max IO size of bio as PAGE_SIZE * bio->bi_max_vecs. However IO alignment feature of f2fs always has that assumption, so finally, it may cause panic during IO submission as below stack. kernel BUG at fs/f2fs/data.c:317! RIP: 0010:__submit_merged_bio+0x8b0/0x8c0 Call Trace: f2fs_submit_page_write+0x3cd/0xdd0 do_write_page+0x15d/0x360 f2fs_outplace_write_data+0xd7/0x210 f2fs_do_write_data_page+0x43b/0xf30 __write_data_page+0xcf6/0x1140 f2fs_write_cache_pages+0x3ba/0xb40 f2fs_write_data_pages+0x3dd/0x8b0 do_writepages+0xbb/0x1e0 __writeback_single_inode+0xb6/0x800 writeback_sb_inodes+0x441/0x910 wb_writeback+0x261/0x650 wb_workfn+0x1f9/0x7a0 process_one_work+0x503/0x970 worker_thread+0x7d/0x820 kthread+0x1ad/0x210 ret_from_fork+0x35/0x40 This patch adds one extra condition to check left space in bio while trying merging page to bio, to avoid panic. This bug was reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204043 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs/f2fs/data.c') diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 0686306ed988..5bce20005add 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -503,6 +503,16 @@ static bool io_is_mergeable(struct f2fs_sb_info *sbi, struct bio *bio, block_t last_blkaddr, block_t cur_blkaddr) { + if (F2FS_IO_ALIGNED(sbi) && (fio->type == DATA || fio->type == NODE)) { + unsigned int filled_blocks = + F2FS_BYTES_TO_BLK(bio->bi_iter.bi_size); + unsigned int io_size = F2FS_IO_SIZE(sbi); + unsigned int left_vecs = bio->bi_max_vecs - bio->bi_vcnt; + + /* IOs in bio is aligned and left space of vectors is not enough */ + if (!(filled_blocks % io_size) && left_vecs < io_size) + return false; + } if (!page_is_mergeable(sbi, bio, last_blkaddr, cur_blkaddr)) return false; return io_type_is_mergeable(io, fio); -- cgit v1.2.3