[PATCH] nfs: handle lock context allocation failures in nfs_create_request

[PATCH] nfs: handle lock context allocation failures in nfs_create_request

[Jeff Layton]

nfs_get_lock_context can return NULL on an allocation failure.

Reported-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/nfs/pagelist.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 9194902..137b549 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -65,6 +65,13 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
 	if (req == NULL)
 		return ERR_PTR(-ENOMEM);
 
+	/* get lock context early so we can deal with alloc failures */
+	req->wb_lock_context = nfs_get_lock_context(ctx);
+	if (req->wb_lock_context == NULL) {
+		nfs_page_free(req);
+		return ERR_PTR(-ENOMEM);
+	}
+
 	/* Initialize the request struct. Initially, we assume a
 	 * long write-back delay. This will be adjusted in
 	 * update_nfs_request below if the region is not locked. */
@@ -79,7 +86,6 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
 	req->wb_pgbase	= offset;
 	req->wb_bytes   = count;
 	req->wb_context = get_nfs_open_context(ctx);
-	req->wb_lock_context = nfs_get_lock_context(ctx);
 	kref_init(&req->wb_kref);
 	return req;
 }
-- 
1.7.2.3

Re: [PATCH] nfs: handle lock context allocation failures in nfs_create_request

[Trond Myklebust]

On Thu, 2010-10-28 at 10:10 -0400, Jeff Layton wrote:
> nfs_get_lock_context can return NULL on an allocation failure.
> 
> Reported-by: Steve Dickson <steved@redhat.com>
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> ---
>  fs/nfs/pagelist.c |    8 +++++++-
>  1 files changed, 7 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
> index 9194902..137b549 100644
> --- a/fs/nfs/pagelist.c
> +++ b/fs/nfs/pagelist.c
> @@ -65,6 +65,13 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
>  	if (req == NULL)
>  		return ERR_PTR(-ENOMEM);
>  
> +	/* get lock context early so we can deal with alloc failures */
> +	req->wb_lock_context = nfs_get_lock_context(ctx);
> +	if (req->wb_lock_context == NULL) {
> +		nfs_page_free(req);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
>  	/* Initialize the request struct. Initially, we assume a
>  	 * long write-back delay. This will be adjusted in
>  	 * update_nfs_request below if the region is not locked. */
> @@ -79,7 +86,6 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
>  	req->wb_pgbase	= offset;
>  	req->wb_bytes   = count;
>  	req->wb_context = get_nfs_open_context(ctx);
> -	req->wb_lock_context = nfs_get_lock_context(ctx);
>  	kref_init(&req->wb_kref);
>  	return req;
>  }

Thanks! Applied!

Trond