linux-kernel - [PATCH 02/21] vfs: do_last(): separate O

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Date:	Tue,  5 Jun 2012 15:10:13 +0200
From:	Miklos Szeredi <miklos@...redi.hu>
To:	viro@...IV.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	hch@...radead.org, torvalds@...ux-foundation.org,
	dhowells@...hat.com, mszeredi@...e.cz
Subject: [PATCH 02/21] vfs: do_last(): separate O_CREAT specific code

From: Miklos Szeredi <mszeredi@...e.cz>

Check O_CREAT on the slow lookup paths where necessary.  This allows the rest to
be shared with plain open.

Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
---
 fs/namei.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index d6e8c55..73e824c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2265,22 +2265,23 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 			inode = path->dentry->d_inode;
 		}
 		goto finish_lookup;
-	}
-
-	/* create side of things */
-	/*
-	 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been
-	 * cleared when we got to the last component we are about to look up
-	 */
-	error = complete_walk(nd);
-	if (error)
-		return ERR_PTR(error);
+	} else {
+		/* create side of things */
+		/*
+		 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED
+		 * has been cleared when we got to the last component we are
+		 * about to look up
+		 */
+		error = complete_walk(nd);
+		if (error)
+			return ERR_PTR(error);
 
-	audit_inode(pathname, dir);
-	error = -EISDIR;
-	/* trailing slashes? */
-	if (nd->last.name[nd->last.len])
-		goto exit;
+		audit_inode(pathname, dir);
+		error = -EISDIR;
+		/* trailing slashes? */
+		if (nd->last.name[nd->last.len])
+			goto exit;
+	}
 
 retry_lookup:
 	mutex_lock(&dir->d_inode->i_mutex);
@@ -2296,7 +2297,7 @@ retry_lookup:
 	path->mnt = nd->path.mnt;
 
 	/* Negative dentry, just create the file */
-	if (!dentry->d_inode) {
+	if (!dentry->d_inode && (open_flag & O_CREAT)) {
 		umode_t mode = op->mode;
 		if (!IS_POSIXACL(dir->d_inode))
 			mode &= ~current_umask();
-- 
1.7.7

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