Patchwork ext4: check eh_max before really insert index

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Submitter Robin Dong
Date June 22, 2011, 6:51 a.m.
Message ID <1308725476-5393-1-git-send-email-sanbai@taobao.com>
Download mbox | patch
Permalink /patch/101398/
State Superseded
Headers show

Comments

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(-)
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;
> 
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Patch

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;