On Thu 27-02-20 16:40:25, Ritesh Harjani wrote:
> For indirect block mapping if the i_block > max supported block in inode
> then ext4_ind_map_blocks() returns a -EIO error. But in case of fiemap
> this could be a valid query to ->iomap_begin call.
> So check if the offset >= s_bitmap_maxbytes in ext4_iomap_begin_report(),
> then simply skip calling ext4_map_blocks().
>
> Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
The patch looks good to me. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/inode.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 81fccbae0aea..4364864fc709 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3548,12 +3548,28 @@ static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
> map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
> EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
>
> + /*
> + * Fiemap callers may call for offset beyond s_bitmap_maxbytes.
> + * So handle it here itself instead of querying ext4_map_blocks().
> + * Since ext4_map_blocks() will warn about it and will return
> + * -EIO error.
> + */
> + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
> + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> +
> + if (offset >= sbi->s_bitmap_maxbytes) {
> + map.m_flags = 0;
> + goto set_iomap;
> + }
> + }
> +
> ret = ext4_map_blocks(NULL, inode, &map, 0);
> if (ret < 0)
> return ret;
> if (ret == 0)
> delalloc = ext4_iomap_is_delalloc(inode, &map);
>
> +set_iomap:
> ext4_set_iomap(inode, iomap, &map, offset, length);
> if (delalloc && iomap->type == IOMAP_HOLE)
> iomap->type = IOMAP_DELALLOC;
> --
> 2.21.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
