9p: Optimize TCREATE by eliminating a redundant fid clone.
Venkateswararao Jujjuri [Mon, 10 May 2010 18:08:28 +0000 (18:08 +0000)]
This patch removes a redundant fid clone on the directory fid and hence
reduces a server transaction while creating new filesystem object.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p/vfs_inode.c

index aecfc0c..0ba2db4 100644 (file)
@@ -504,12 +504,11 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
        ofid = NULL;
        fid = NULL;
        name = (char *) dentry->d_name.name;
-       dfid = v9fs_fid_clone(dentry->d_parent);
+       dfid = v9fs_fid_lookup(dentry->d_parent);
        if (IS_ERR(dfid)) {
                err = PTR_ERR(dfid);
-               P9_DPRINTK(P9_DEBUG_VFS, "fid clone failed %d\n", err);
-               dfid = NULL;
-               goto error;
+               P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
+               return ERR_PTR(err);
        }
 
        /* clone a fid to use for creation */
@@ -517,8 +516,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
        if (IS_ERR(ofid)) {
                err = PTR_ERR(ofid);
                P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
-               ofid = NULL;
-               goto error;
+               return ERR_PTR(err);
        }
 
        err = p9_client_fcreate(ofid, name, perm, mode, extension);
@@ -528,14 +526,13 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
        }
 
        /* now walk from the parent so we can get unopened fid */
-       fid = p9_client_walk(dfid, 1, &name, 0);
+       fid = p9_client_walk(dfid, 1, &name, 1);
        if (IS_ERR(fid)) {
                err = PTR_ERR(fid);
                P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
                fid = NULL;
                goto error;
-       } else
-               dfid = NULL;
+       }
 
        /* instantiate inode and assign the unopened fid to the dentry */
        inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
@@ -558,9 +555,6 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
        return ofid;
 
 error:
-       if (dfid)
-               p9_client_clunk(dfid);
-
        if (ofid)
                p9_client_clunk(ofid);