2011-06-22 06:51:26

by Robin Dong

Subject: [PATCH] ext4: check eh_max before really insert index

Check eh_entries/eh_max before really insert index.

Signed-off-by: Robin Dong <[email protected]>
---
fs/ext4/extents.c | 18 ++++++++++--------
1 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index eb63c7b..a742e6e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -776,6 +776,16 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
logical, le32_to_cpu(curp->p_idx->ei_block));
return -EIO;
}
+
+ if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) + 1
+ > le16_to_cpu(curp->p_hdr->eh_max))) {
+ EXT4_ERROR_INODE(inode,
+ "eh_entries %d + 1 > eh_max %d!",
+ le16_to_cpu(curp->p_hdr->eh_entries),
+ le16_to_cpu(curp->p_hdr->eh_max));
+ return -EIO;
+ }
+
len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
/* insert after */
@@ -805,14 +815,6 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
ext4_idx_store_pblock(ix, ptr);
le16_add_cpu(&curp->p_hdr->eh_entries, 1);

- if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
- > le16_to_cpu(curp->p_hdr->eh_max))) {
- EXT4_ERROR_INODE(inode,
- "eh_entries %d > eh_max %d!",
- le16_to_cpu(curp->p_hdr->eh_entries),
- le16_to_cpu(curp->p_hdr->eh_max));
- return -EIO;
- }
if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
return -EIO;
--
1.7.1

2011-06-22 08:38:30

by Lukas Czerner

Subject: Re: [PATCH] ext4: check eh_max before really insert index

On Wed, 22 Jun 2011, Robin Dong wrote:

> Check eh_entries/eh_max before really insert index.

Hi Robin,

thanks for the patch. Could you please describe why is the change
needed and what problem it fixes in the commit description. It is
not clear from the patch itself.

Thanks!
-Lukas

>
> Signed-off-by: Robin Dong <[email protected]>
> ---
> fs/ext4/extents.c | 18 ++++++++++--------
> 1 files changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index eb63c7b..a742e6e 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -776,6 +776,16 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
> logical, le32_to_cpu(curp->p_idx->ei_block));
> return -EIO;
> }
> +
> + if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) + 1
> + > le16_to_cpu(curp->p_hdr->eh_max))) {
> + EXT4_ERROR_INODE(inode,
> + "eh_entries %d + 1 > eh_max %d!",
> + le16_to_cpu(curp->p_hdr->eh_entries),
> + le16_to_cpu(curp->p_hdr->eh_max));
> + return -EIO;
> + }
> +
> len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
> if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
> /* insert after */
> @@ -805,14 +815,6 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
> ext4_idx_store_pblock(ix, ptr);
> le16_add_cpu(&curp->p_hdr->eh_entries, 1);
>
> - if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
> - > le16_to_cpu(curp->p_hdr->eh_max))) {
> - EXT4_ERROR_INODE(inode,
> - "eh_entries %d > eh_max %d!",
> - le16_to_cpu(curp->p_hdr->eh_entries),
> - le16_to_cpu(curp->p_hdr->eh_max));
> - return -EIO;
> - }
> if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
> EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
> return -EIO;
>