NFS: Prevent garbage cinfo->ds from leaking out

Fred Isaman · Trond Myklebust · commit df0117481cd9 · 2012-04-27T14:10:39.000-04:00
This is a bugfix that applies on top of the previous directio patches,
that fixes a bug introduced in "NFS: create struct nfs_commit_info".

Signed-off-by: Fred Isaman &lt;iisaman@netapp.com&gt;
Signed-off-by: Trond Myklebust &lt;Trond.Myklebust@netapp.com&gt;
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
@@ -1184,7 +1184,12 @@ filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
 static struct pnfs_ds_commit_info *
 filelayout_get_ds_info(struct inode *inode)
 {
-	return &FILELAYOUT_FROM_HDR(NFS_I(inode)->layout)->commit_info;
+	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
+
+	if (layout == NULL)
+		return NULL;
+	else
+		return &FILELAYOUT_FROM_HDR(layout)->commit_info;
 }
 
 static struct pnfs_layoutdriver_type filelayout_type = {

Original file line number	Diff line number	Diff line change
`@@ -1184,7 +1184,12 @@ filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)`
`1184`	`1184`	`static struct pnfs_ds_commit_info *`
`1185`	`1185`	`filelayout_get_ds_info(struct inode *inode)`
`1186`	`1186`	`{`
`1187`		`- return &FILELAYOUT_FROM_HDR(NFS_I(inode)->layout)->commit_info;`
	`1187`	`+ struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;`
	`1188`	`+`
	`1189`	`+ if (layout == NULL)`
	`1190`	`+ return NULL;`
	`1191`	`+ else`
	`1192`	`+ return &FILELAYOUT_FROM_HDR(layout)->commit_info;`
`1188`	`1193`	`}`
`1189`	`1194`
`1190`	`1195`	`static struct pnfs_layoutdriver_type filelayout_type = {`