ext4: check eh_max before really insert index

Submitted by Robin Dong on June 22, 2011, 6:51 a.m.

Details

Message ID 1308725476-5393-1-git-send-email-sanbai@taobao.com
State Superseded, archived
Headers show

Commit Message

Robin Dong June 22, 2011, 6:51 a.m.
Check eh_entries/eh_max before really insert index.

Signed-off-by: Robin Dong <sanbai@taobao.com>
---
 fs/ext4/extents.c |   18 ++++++++++--------
 1 files changed, 10 insertions(+), 8 deletions(-)

Comments

Lukas Czerner June 22, 2011, 8:38 a.m.
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 <sanbai@taobao.com>
> ---
>  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;
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch hide | download patch | download mbox

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;