On Wed 30-04-25 09:12:59, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
>
> For the extents inodes, the maxbytes should be sb->s_maxbytes instead of
> sbi->s_bitmap_maxbytes. Correct the maxbytes value to correct the
> behavior of punch hole.
>
> Fixes: 2da376228a24 ("ext4: limit length to bitmap_maxbytes - blocksize in punch_hole")
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Thinking about this some more...
> @@ -4015,6 +4015,12 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
> trace_ext4_punch_hole(inode, offset, length, 0);
> WARN_ON_ONCE(!inode_is_locked(inode));
>
> + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> + max_end = sb->s_maxbytes;
> + else
> + max_end = EXT4_SB(sb)->s_bitmap_maxbytes;
> + max_end -= sb->s_blocksize;
I think the -= sb->s_blocksize is needed only for indirect-block based
scheme (due to an implementation quirk in ext4_ind_remove_space()). But
ext4_ext_remove_space() should be fine with punch hole ending right at
sb->s_maxbytes. And since I find it somewhat odd that you can create file
upto s_maxbytes but cannot punch hole to the end, it'd limit that behavior
as much as possible. Ideally we'd fix ext4_ind_remove_space() but I can't
be really bothered for the ancient format...
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
