On 12/23/10 10:17 PM, Kazuya Mio wrote:
> Hi,
>
> We can create 4402345721856 byte file with indirect block mapping.
> However, if we grow an indirect-block file to the size with ftruncate(),
> we can see the ext4 warning. The following patch fixes this problem.
Ted, ping^2 on this one?
-Eric
> How to reproduce:
> # dd if=/dev/zero of=/mnt/mp1/hoge bs=1 count=0 seek=4402345721856
> 0+0 records in
> 0+0 records out
> 0 bytes (0 B) copied, 0.000221428 s, 0.0 kB/s
> # tail -n 1 /var/log/messages
> Nov 25 15:10:27 test kernel: EXT4-fs warning (device sda8): ext4_block_to_path:345: block 1074791436 > max in inode 12
>
> Signed-off-by: Kazuya Mio <k-mio@xxxxxxxxxxxxx>
> ---
> fs/ext4/inode.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 05a0790..c429753 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4677,8 +4677,8 @@ void ext4_truncate(struct inode *inode)
> Indirect chain[4];
> Indirect *partial;
> __le32 nr = 0;
> - int n;
> - ext4_lblk_t last_block;
> + int n = 0;
> + ext4_lblk_t last_block, max_block;
> unsigned blocksize = inode->i_sb->s_blocksize;
>
> if (!ext4_can_truncate(inode))
> @@ -4700,14 +4700,18 @@ void ext4_truncate(struct inode *inode)
>
> last_block = (inode->i_size + blocksize-1)
> >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
> + max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
> + >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
>
> if (inode->i_size & (blocksize - 1))
> if (ext4_block_truncate_page(handle, mapping, inode->i_size))
> goto out_stop;
>
> - n = ext4_block_to_path(inode, last_block, offsets, NULL);
> - if (n == 0)
> - goto out_stop; /* error */
> + if (last_block != max_block) {
> + n = ext4_block_to_path(inode, last_block, offsets, NULL);
> + if (n == 0)
> + goto out_stop; /* error */
> + }
>
> /*
> * OK. This truncate is going to happen. We add the inode to the
> @@ -4738,7 +4742,13 @@ void ext4_truncate(struct inode *inode)
> */
> ei->i_disksize = inode->i_size;
>
> - if (n == 1) { /* direct blocks */
> + if (last_block == max_block) {
> + /*
> + * It is unnecessary to free any data blocks if last_block is
> + * equal to the indirect block limit.
> + */
> + goto out_unlock;
> + } else if (n == 1) { /* direct blocks */
> ext4_free_data(handle, inode, NULL, i_data+offsets[0],
> i_data + EXT4_NDIR_BLOCKS);
> goto do_indirects;
> @@ -4798,6 +4808,7 @@ do_indirects:
> ;
> }
>
> +out_unlock:
> up_write(&ei->i_data_sem);
> inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
> ext4_mark_inode_dirty(handle, inode);
> --
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