Make nfs_file_cred more robust.
As not all files have an associated open_context (e.g. device special
files), it is safest to test for the existence of the open context
before de-referencing it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c910413..83e700a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1659,8 +1659,10 @@
struct nfs_open_context *ctx;
ctx = nfs_file_open_context(sattr->ia_file);
- cred = ctx->cred;
- state = ctx->state;
+ if (ctx) {
+ cred = ctx->cred;
+ state = ctx->state;
+ }
}
status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index ac8d023..4eaa834 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -367,8 +367,12 @@
static inline struct rpc_cred *nfs_file_cred(struct file *file)
{
- if (file != NULL)
- return nfs_file_open_context(file)->cred;
+ if (file != NULL) {
+ struct nfs_open_context *ctx =
+ nfs_file_open_context(file);
+ if (ctx)
+ return ctx->cred;
+ }
return NULL;
}