fs: provide rcu-walk aware permission i_ops

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

2 files changed, 8 insertions, 4 deletions

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 71d4bc8464e0..77b48c8fab17 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -785,15 +785,19 @@ out_err:
         return err;
 }
 
-int nilfs_permission(struct inode *inode, int mask)
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags)
 {
-        struct nilfs_root *root = NILFS_I(inode)->i_root;
+        struct nilfs_root *root;
+
+        if (flags & IPERM_FLAG_RCU)
+                return -ECHILD;
 
+        root = NILFS_I(inode)->i_root;
         if ((mask & MAY_WRITE) && root &&
             root->cno != NILFS_CPTREE_CURRENT_CNO)
                 return -EROFS; /* snapshot is not writable */
 
-        return generic_permission(inode, mask, NULL);
+        return generic_permission(inode, mask, flags, NULL);
 }
 
 int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index f7560da5a567..0ca98823db59 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -256,7 +256,7 @@ extern void nilfs_update_inode(struct inode *, struct buffer_head *);
 extern void nilfs_truncate(struct inode *);
 extern void nilfs_evict_inode(struct inode *);
 extern int nilfs_setattr(struct dentry *, struct iattr *);
-int nilfs_permission(struct inode *inode, int mask);
+int nilfs_permission(struct inode *inode, int mask, unsigned int flags);
 extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *,
                                   struct buffer_head **);
 extern int nilfs_inode_dirty(struct inode *);