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 <huangjianan@oppo.com>
Signed-off-by: Guo Weichao <guoweichao@oppo.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 398498f..0e749cf 100644 (file)
--- 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,