GFS2: Only do one directory search on create

Creation of a new inode requires a directory search in order to ensure
that we are not trying to create an inode with the same name as an
existing one. This was hidden away inside the create_ok() function.

In the case that there was an existing inode, and a lookup can be
substituted for a create (which is the case with regular files
when the O_EXCL flag is not in use) then we were doing a second
lookup in order to return the inode.

This patch merges these two lookups into one. This can be done by
passing a flag to gfs2_dir_search() to tell it to just return -EEXIST
in the cases where we don't actually want to look up the inode.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 10 insertions, 17 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 5fbb8dfb4653..ede16ae784e2 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -313,7 +313,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
                         goto out;
         }
 
-        inode = gfs2_dir_search(dir, name);
+        inode = gfs2_dir_search(dir, name, false);
         if (IS_ERR(inode))
                 error = PTR_ERR(inode);
 out:
@@ -346,17 +346,6 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
         if (!dip->i_inode.i_nlink)
                 return -ENOENT;
 
-        error = gfs2_dir_check(&dip->i_inode, name, NULL);
-        switch (error) {
-        case -ENOENT:
-                error = 0;
-                break;
-        case 0:
-                return -EEXIST;
-        default:
-                return error;
-        }
-
         if (dip->i_entries == (u32)-1)
                 return -EFBIG;
         if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
@@ -584,14 +573,18 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
                 goto fail;
 
         error = create_ok(dip, name, mode);
-        if ((error == -EEXIST) && S_ISREG(mode) && !excl) {
-                inode = gfs2_lookupi(dir, &dentry->d_name, 0);
+        if (error)
+                goto fail_gunlock;
+
+        inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);
+        error = PTR_ERR(inode);
+        if (!IS_ERR(inode)) {
                 gfs2_glock_dq_uninit(ghs);
                 d_instantiate(dentry, inode);
-                return PTR_RET(inode);
-        }
-        if (error)
+                return 0;
+        } else if (error != -ENOENT) {
                 goto fail_gunlock;
+        }
 
         arq = error = gfs2_diradd_alloc_required(dir, name);
         if (error < 0)