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>

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index b631c904346084b5fb7b7d96985e724e7b4173a3..f0c70529948f004252b57f4c7a1eb4b2ddf5b142 100644 (file)
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -1555,9 +1555,9 @@ out:
 
 /**
  * gfs2_dir_search - Search a directory
- * @dip: The GFS2 inode
- * @filename:
- * @inode:
+ * @dip: The GFS2 dir inode
+ * @name: The name we are looking up
+ * @fail_on_exist: Fail if the name exists rather than looking it up
  *
  * This routine searches a directory for a file or another directory.
  * Assumes a glock is held on dip.
@@ -1565,22 +1565,25 @@ out:
  * Returns: errno
  */
 
-struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)
+struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,
+                             bool fail_on_exist)
 {
        struct buffer_head *bh;
        struct gfs2_dirent *dent;
-       struct inode *inode;
+       u64 addr, formal_ino;
+       u16 dtype;
 
        dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);
        if (dent) {
                if (IS_ERR(dent))
                        return ERR_CAST(dent);
-               inode = gfs2_inode_lookup(dir->i_sb, 
-                               be16_to_cpu(dent->de_type),
-                               be64_to_cpu(dent->de_inum.no_addr),
-                               be64_to_cpu(dent->de_inum.no_formal_ino), 0);
+               dtype = be16_to_cpu(dent->de_type);
+               addr = be64_to_cpu(dent->de_inum.no_addr);
+               formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);
                brelse(bh);
-               return inode;
+               if (fail_on_exist)
+                       return ERR_PTR(-EEXIST);
+               return gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino, 0);
        }
        return ERR_PTR(-ENOENT);
 }

diff --git a/fs/gfs2/dir.h b/fs/gfs2/dir.h
index 98c960beab35e479460771d19a17e24259a4fe1a..d3f273870b4915f6f24afc77b0dc36208c0ee202 100644 (file)
--- a/fs/gfs2/dir.h
+++ b/fs/gfs2/dir.h
@@ -18,7 +18,8 @@ struct gfs2_inode;
 struct gfs2_inum;
 
 extern struct inode *gfs2_dir_search(struct inode *dir,
-                                    const struct qstr *filename);
+                                    const struct qstr *filename,
+                                    bool fail_on_exist);
 extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
                          const struct gfs2_inode *ip);
 extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 5fbb8dfb46536c604951cf1d3112886f8da809a8..ede16ae784e21261b2a937cb3bf0f63488f0aaf1 100644 (file)
--- 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)