Commit 36e4d958 authored by huangjianan@oppo.com's avatar huangjianan@oppo.com Committed by Jaegeuk Kim
Browse files

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: default avatarHuang Jianan <huangjianan@oppo.com>
Signed-off-by: default avatarGuo Weichao <guoweichao@oppo.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 1da66103

fs/f2fs/data.c

+88 −21
Original line number Diff line number Diff line
@@ -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 @@ static int check_swap_activate(struct swap_info_struct *sis, 
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,