If the swapfile isn't created by pin and fallocate, it cann't be guaranteed section-aligned, so it may be selected by f2fs gc. When gc_pin_file_threshold is reached, the address of swapfile may change, but won't be synchroniz to swap_extent, so swap will write to wrong address, which will cause data corruption.
Signed-off-by: Huang Jianan <huangjia...@oppo.com> Signed-off-by: Guo Weichao <guoweic...@oppo.com> --- fs/f2fs/data.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 4dbc1cafc55d..3e523d6e4643 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3781,11 +3781,63 @@ int f2fs_migrate_page(struct address_space *mapping, #endif #ifdef CONFIG_SWAP +static int f2fs_check_file_aligned(struct inode *inode) +{ + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); + block_t main_blkaddr = SM_I(sbi)->main_blkaddr; + block_t cur_lblock; + block_t last_lblock; + block_t pblock; + unsigned long len; + unsigned long nr_pblocks; + unsigned int blocks_per_sec = sbi->blocks_per_seg * sbi->segs_per_sec; + int ret; + + cur_lblock = 0; + last_lblock = bytes_to_blks(inode, i_size_read(inode)); + len = i_size_read(inode); + + while (cur_lblock < last_lblock) { + struct f2fs_map_blocks map; + pgoff_t next_pgofs; + + memset(&map, 0, sizeof(map)); + map.m_lblk = cur_lblock; + map.m_len = bytes_to_blks(inode, len) - cur_lblock; + map.m_next_pgofs = &next_pgofs; + map.m_seg_type = NO_CHECK_TYPE; + + ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP); + + if (ret) + goto err_out; + + /* hole */ + if (!(map.m_flags & F2FS_MAP_FLAGS)) + goto err_out; + + pblock = map.m_pblk; + nr_pblocks = map.m_len; + + if ((pblock - main_blkaddr) & (blocks_per_sec - 1) || + nr_pblocks & (blocks_per_sec - 1)) + goto err_out; + + cur_lblock += nr_pblocks; + } + + return 0; +err_out: + pr_err("swapon: swapfile isn't section-aligned\n"); + return -EINVAL; +} + static int check_swap_activate_fast(struct swap_info_struct *sis, struct file *swap_file, sector_t *span) { struct address_space *mapping = swap_file->f_mapping; struct inode *inode = mapping->host; + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); sector_t cur_lblock; sector_t last_lblock; sector_t pblock; @@ -3793,6 +3845,7 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, sector_t highest_pblock = 0; int nr_extents = 0; unsigned long nr_pblocks; + unsigned int blocks_per_sec = sbi->blocks_per_seg * sbi->segs_per_sec; u64 len; int ret; @@ -3827,6 +3880,13 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, pblock = map.m_pblk; nr_pblocks = map.m_len; + if ((pblock - SM_I(sbi)->main_blkaddr) & (blocks_per_sec - 1) || + nr_pblocks & (blocks_per_sec - 1)) { + pr_err("swapon: swapfile isn't section-aligned\n"); + ret = -EINVAL; + goto out; + } + if (cur_lblock + nr_pblocks >= sis->max) nr_pblocks = sis->max - cur_lblock; @@ -3878,6 +3938,9 @@ static int check_swap_activate(struct swap_info_struct *sis, if (PAGE_SIZE == F2FS_BLKSIZE) return check_swap_activate_fast(sis, swap_file, span); + if (f2fs_check_file_aligned(inode)) + return -EINVAL; + blocks_per_page = bytes_to_blks(inode, PAGE_SIZE); /* -- 2.25.1