1 files changed, 11 insertions, 0 deletions

diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index efd23f481704..beb6e691f70a 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -364,6 +364,9 @@ struct inode_operations {
         ssize_t (*listxattr) (struct dentry *, char *, size_t);
         int (*removexattr) (struct dentry *, const char *);
         void (*update_time)(struct inode *, struct timespec *, int);
+        struct file * (*atomic_open)(struct inode *, struct dentry *,
+                                struct opendata *, unsigned open_flag,
+                                umode_t create_mode, bool *created);
 };
 
 Again, all methods are called without any locks being held, unless
@@ -476,6 +479,14 @@ otherwise noted.
         an inode.  If this is not defined the VFS will update the inode itself
         and call mark_inode_dirty_sync.
 
+  atomic_open: called on the last component of an open.  Using this optional
+        method the filesystem can look up, possibly create and open the file in
+        one atomic operation.  If it cannot perform this (e.g. the file type
+        turned out to be wrong) it may signal this by returning NULL instead of
+        an open struct file pointer.  This method is only called if the last
+        component is negative or needs lookup.  Cached positive dentries are
+        still handled by f_op->open().
+
 The Address Space Object
 ========================