mkdir /mnt/test/comp f2fs_io setflags compression /mnt/test/comp dd if=/dev/zero of=/mnt/test/comp/testfile bs=16k count=1 truncate --size 13 /mnt/test/comp/testfile In the above scenario, we can get a BUG_ON. kernel BUG at fs/f2fs/segment.c:3589! Call Trace: do_write_page+0x78/0x390 [f2fs] f2fs_outplace_write_data+0x62/0xb0 [f2fs] f2fs_do_write_data_page+0x275/0x740 [f2fs] f2fs_write_single_data_page+0x1dc/0x8f0 [f2fs] f2fs_write_multi_pages+0x1e5/0xae0 [f2fs] f2fs_write_cache_pages+0xab1/0xc60 [f2fs] f2fs_write_data_pages+0x2d8/0x330 [f2fs] do_writepages+0xcf/0x270 __writeback_single_inode+0x44/0x350 writeback_sb_inodes+0x242/0x530 __writeback_inodes_wb+0x54/0xf0 wb_writeback+0x192/0x310 wb_workfn+0x30d/0x400 The reason is we gave CURSEG_ALL_DATA_ATGC to COMPR_ADDR where the page was set the gcing flag by set_cluster_dirty(). Cc: stable@xxxxxxxxxxxxxxx Fixes: 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration") Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> --- fs/f2fs/segment.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 6e8a4b332ad5..ce2300391031 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3484,6 +3484,7 @@ static int __get_segment_type_6(struct f2fs_io_info *fio) if (fio->sbi->am.atgc_enabled && (fio->io_type == FS_DATA_IO) && (fio->sbi->gc_mode != GC_URGENT_HIGH) && + __is_valid_data_blkaddr(fio->old_blkaddr) && !is_inode_flag_set(inode, FI_OPU_WRITE)) return CURSEG_ALL_DATA_ATGC; else -- 2.45.2.627.g7a2c4fd464-goog