On Tue, Jun 16, 2009 at 07:57:59PM -0500, Eric Sandeen wrote:
> libext2fs: write only core inode in update_path()
>
> The ext2_extent_handle only has a struct ext2_inode allocated on
> it, and the same amount copied into it in that same function,
> but in update_path() we're possibly writing out more than that -
> for example 256 bytes, from that address. This causes uninitialized
> memory to get written to disk, overwriting the parts of the
> inode past the osd2 member (the end of the smaller structure).
Oh, I see. The bug was introduced by commit 84b239ae
libext2fs: add ext2fs_extent_open2
The patch below adds a function, ext2fs_extent_open2(), that behaves
as ext2fs_extent_open(), but will use the user-supplied inode
structure when opening an extent instead of reading the inode from
disk. It also changes several of the calls to extent_open() to use
this enhancement.
Signed-off-by: Nic Case <number9652@xxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Which replaced ext2fs_read_inode_full with ext2fs_read_inode(); which
is fine, extents.c doesn't need to use the full inode; but it didn't
change ext2fs_write_inode_full() with ext2fs_write_inode().
> diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
> index b7eb617..0dfee62 100644
> --- a/lib/ext2fs/extent.c
> +++ b/lib/ext2fs/extent.c
> @@ -547,7 +547,7 @@ static errcode_t update_path(ext2_extent_handle_t handle)
>
> if (handle->level == 0) {
> retval = ext2fs_write_inode_full(handle->fs, handle->ino,
> - handle->inode, EXT2_INODE_SIZE(handle->fs->super));
> + handle->inode, sizeof(struct ext2_inode));
Probably it would be better/simpler to replace this with:
retval = ext2fs_write_inode(handle->fs, handle->ino,
handle->inode);
- Ted
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