From 41fb6e678320f556f43e9dc1eb2a518560b83be5 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Thu, 14 Jun 2012 16:13:46 +0100
Subject: [PATCH] --- yaml --- r: 312924 b: refs/heads/master c:
 1acf0af9b981027f3e73e93f0d3f85abdc794f71 h: refs/heads/master v: v3

---
 [refs]           |  2 +-
 trunk/fs/namei.c | 29 ++++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 9c2d869a2de0..f7a6b185071d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 312b63fba9e88a0dcf800834b8ede8716bcc1e17
+refs/heads/master: 1acf0af9b981027f3e73e93f0d3f85abdc794f71
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index ffcd4e114b6e..5abab9176903 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -2192,6 +2192,19 @@ static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
 	return security_inode_create(dir->dentry->d_inode, dentry, mode);
 }
 
+/*
+ * Attempt to atomically look up, create and open a file from a negative
+ * dentry.
+ *
+ * Returns 0 if successful.  The file will have been created and attached to
+ * @file by the filesystem calling finish_open().
+ *
+ * Returns 1 if the file was looked up only or didn't need creating.  The
+ * caller will need to perform the open themselves.  @path will have been
+ * updated to point to the new dentry.  This may be negative.
+ *
+ * Returns an error code otherwise.
+ */
 static int atomic_open(struct nameidata *nd, struct dentry *dentry,
 			struct path *path, struct file *file,
 			const struct open_flags *op,
@@ -2336,12 +2349,22 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
 }
 
 /*
- * Lookup, maybe create and open the last component
+ * Look up and maybe create and open the last component.
  *
  * Must be called with i_mutex held on parent.
  *
- * Returns open file or NULL on success, error otherwise.  NULL means no open
- * was performed, only lookup.
+ * Returns 0 if the file was successfully atomically created (if necessary) and
+ * opened.  In this case the file will be returned attached to @file.
+ *
+ * Returns 1 if the file was not completely opened at this time, though lookups
+ * and creations will have been performed and the dentry returned in @path will
+ * be positive upon return if O_CREAT was specified.  If O_CREAT wasn't
+ * specified then a negative dentry may be returned.
+ *
+ * An error code is returned otherwise.
+ *
+ * FILE_CREATE will be set in @*opened if the dentry was created and will be
+ * cleared otherwise prior to returning.
  */
 static int lookup_open(struct nameidata *nd, struct path *path,
 			struct file *file,