fs: provide rcu-walk aware permission i_ops

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 07f4b5e675fc..f738599fd8cd 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -985,12 +985,15 @@ static int fuse_access(struct inode *inode, int mask)
  * access request is sent.  Execute permission is still checked
  * locally based on file mode.
  */
-static int fuse_permission(struct inode *inode, int mask)
+static int fuse_permission(struct inode *inode, int mask, unsigned int flags)
 {
         struct fuse_conn *fc = get_fuse_conn(inode);
         bool refreshed = false;
         int err = 0;
 
+        if (flags & IPERM_FLAG_RCU)
+                return -ECHILD;
+
         if (!fuse_allow_task(fc, current))
                 return -EACCES;
 
@@ -1005,7 +1008,7 @@ static int fuse_permission(struct inode *inode, int mask)
         }
 
         if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
-                err = generic_permission(inode, mask, NULL);
+                err = generic_permission(inode, mask, flags, NULL);
 
                 /* If permission is denied, try to refresh file
                    attributes.  This is also needed, because the root
@@ -1013,7 +1016,8 @@ static int fuse_permission(struct inode *inode, int mask)
                 if (err == -EACCES && !refreshed) {
                         err = fuse_do_getattr(inode, NULL, NULL);
                         if (!err)
-                                err = generic_permission(inode, mask, NULL);
+                                err = generic_permission(inode, mask,
+                                                        flags, NULL);
                 }
 
                 /* Note: the opposite of the above test does not