From 36e4d95891ed37eb98a660babec749be3fb35fd9 Mon Sep 17 00:00:00 2001 From: "huangjianan@oppo.com" Date: Mon, 1 Mar 2021 12:58:44 +0800 Subject: [PATCH] f2fs: check if swapfile is section-alligned If the swapfile isn't created by pin and fallocate, it can'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 synchronized to swap_extent, so swap will write to wrong address, which will cause data corruption. Signed-off-by: Huang Jianan Signed-off-by: Guo Weichao Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 109 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 88 insertions(+), 21 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 398498fb99d5..0e749cf60e11 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3780,11 +3780,64 @@ int f2fs_migrate_page(struct address_space *mapping, #endif #ifdef CONFIG_SWAP +static int f2fs_is_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 nr_pblocks; + unsigned int blocks_per_sec = BLKS_PER_SEC(sbi); + int ret = 0; + + cur_lblock = 0; + last_lblock = bytes_to_blks(inode, i_size_read(inode)); + + while (cur_lblock < last_lblock) { + struct f2fs_map_blocks map; + + memset(&map, 0, sizeof(map)); + map.m_lblk = cur_lblock; + map.m_len = last_lblock - cur_lblock; + map.m_next_pgofs = NULL; + map.m_next_extent = NULL; + map.m_seg_type = NO_CHECK_TYPE; + map.m_may_create = false; + + ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP); + if (ret) + goto out; + + /* hole */ + if (!(map.m_flags & F2FS_MAP_FLAGS)) { + f2fs_err(sbi, "Swapfile has holes\n"); + ret = -ENOENT; + goto out; + } + + pblock = map.m_pblk; + nr_pblocks = map.m_len; + + if ((pblock - main_blkaddr) & (blocks_per_sec - 1) || + nr_pblocks & (blocks_per_sec - 1)) { + f2fs_err(sbi, "Swapfile does not align to section"); + ret = -EINVAL; + goto out; + } + + cur_lblock += nr_pblocks; + } +out: + return ret; +} + 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; @@ -3792,8 +3845,8 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, sector_t highest_pblock = 0; int nr_extents = 0; unsigned long nr_pblocks; - u64 len; - int ret; + unsigned int blocks_per_sec = BLKS_PER_SEC(sbi); + int ret = 0; /* * Map all the blocks into the extent list. This code doesn't try @@ -3801,31 +3854,41 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, */ cur_lblock = 0; last_lblock = bytes_to_blks(inode, i_size_read(inode)); - len = i_size_read(inode); while (cur_lblock < last_lblock && cur_lblock < sis->max) { struct f2fs_map_blocks map; - pgoff_t next_pgofs; cond_resched(); 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_len = last_lblock - cur_lblock; + map.m_next_pgofs = NULL; + map.m_next_extent = NULL; map.m_seg_type = NO_CHECK_TYPE; + map.m_may_create = false; ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP); if (ret) - goto err_out; + goto out; /* hole */ - if (!(map.m_flags & F2FS_MAP_FLAGS)) - goto err_out; + if (!(map.m_flags & F2FS_MAP_FLAGS)) { + f2fs_err(sbi, "Swapfile has holes\n"); + ret = -ENOENT; + goto out; + } 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)) { + f2fs_err(sbi, "Swapfile does not align to section"); + ret = -EINVAL; + goto out; + } + if (cur_lblock + nr_pblocks >= sis->max) nr_pblocks = sis->max - cur_lblock; @@ -3854,9 +3917,6 @@ static int check_swap_activate_fast(struct swap_info_struct *sis, sis->highest_bit = cur_lblock - 1; out: return ret; -err_out: - pr_err("swapon: swapfile has holes\n"); - return -EINVAL; } /* Copied from generic_swapfile_activate() to check any holes */ @@ -3865,6 +3925,7 @@ static int check_swap_activate(struct swap_info_struct *sis, { struct address_space *mapping = swap_file->f_mapping; struct inode *inode = mapping->host; + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); unsigned blocks_per_page; unsigned long page_no; sector_t probe_block; @@ -3872,11 +3933,15 @@ static int check_swap_activate(struct swap_info_struct *sis, sector_t lowest_block = -1; sector_t highest_block = 0; int nr_extents = 0; - int ret; + int ret = 0; if (PAGE_SIZE == F2FS_BLKSIZE) return check_swap_activate_fast(sis, swap_file, span); + ret = f2fs_is_file_aligned(inode); + if (ret) + goto out; + blocks_per_page = bytes_to_blks(inode, PAGE_SIZE); /* @@ -3891,13 +3956,14 @@ static int check_swap_activate(struct swap_info_struct *sis, unsigned block_in_page; sector_t first_block; sector_t block = 0; - int err = 0; cond_resched(); block = probe_block; - err = bmap(inode, &block); - if (err || !block) + ret = bmap(inode, &block); + if (ret) + goto out; + if (!block) goto bad_bmap; first_block = block; @@ -3913,9 +3979,10 @@ static int check_swap_activate(struct swap_info_struct *sis, block_in_page++) { block = probe_block + block_in_page; - err = bmap(inode, &block); - - if (err || !block) + ret = bmap(inode, &block); + if (ret) + goto out; + if (!block) goto bad_bmap; if (block != first_block + block_in_page) { @@ -3955,8 +4022,8 @@ reprobe: out: return ret; bad_bmap: - pr_err("swapon: swapfile has holes\n"); - return -EINVAL; + f2fs_err(sbi, "Swapfile has holes\n"); + return -ENOENT; } static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file, -- 2.25.1