Hi Jianan,

On 2021/2/27 20:02, Huang Jianan via Linux-f2fs-devel wrote:
If the swapfile isn't created by pin and fallocate, it cann't be

Typo:

can't

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

synchronized

address, which will cause data corruption.

Signed-off-by: Huang Jianan <[email protected]>
Signed-off-by: Guo Weichao <[email protected]>
---
  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)

f2fs_check_file_alignment() or f2fs_is_file_aligned()?

+{
+       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;

unsigned int blocks_per_sec = BLKS_PER_SEC(sbi);

+       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_len = last_lblock - cur_lblock;

+               map.m_next_pgofs = &next_pgofs;

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);
+

Unneeded blank line.

+               if (ret)
+                       goto err_out;
+
+               /* hole */
+               if (!(map.m_flags & F2FS_MAP_FLAGS))

ret = -ENOENT;

+                       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))

ret = -EINVAL;

+                       goto err_out;
+
+               cur_lblock += nr_pblocks;
+       }
+
+       return 0;
+err_out:
+       pr_err("swapon: swapfile isn't section-aligned\n");

We should show above message only after we fail in check condition:

        if ((pblock - main_blkaddr) & (blocks_per_sec - 1) ||
                nr_pblocks & (blocks_per_sec - 1)) {
                f2fs_err(sbi, "Swapfile does not align to section");
                goto err_out;
        }

And please use f2fs_{err,warn,info..} macro rather than pr_{err,warn,info..}.

Could you please fix above related issues in check_swap_activate_fast() as well.

+       return -EINVAL;

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;
@@ -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;

Ditto,

        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");

Ditto,

+                       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))

ret = f2fs_check_file_aligned();
if (ret)
        return ret;

Thanks,

+               return -EINVAL;
+
        blocks_per_page = bytes_to_blks(inode, PAGE_SIZE);
/*



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