vfs: rename: use common code for dir and non-dir

There's actually very little difference between vfs_rename_dir() and
vfs_rename_other() so move both inline into vfs_rename() which still stays
reasonably readable.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 75 insertions, 112 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 2e86d2c4ec8a..12b8f56ba942 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3973,7 +3973,27 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
         return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
-/*
+/**
+ * vfs_rename - rename a filesystem object
+ * @old_dir:    parent of source
+ * @old_dentry: source
+ * @new_dir:    parent of destination
+ * @new_dentry: destination
+ * @delegated_inode: returns an inode needing a delegation break
+ *
+ * The caller must hold multiple mutexes--see lock_rename()).
+ *
+ * If vfs_rename discovers a delegation in need of breaking at either
+ * the source or destination, it will return -EWOULDBLOCK and return a
+ * reference to the inode in delegated_inode.  The caller should then
+ * break the delegation and retry.  Because breaking a delegation may
+ * take a long time, the caller should drop all locks before doing
+ * so.
+ *
+ * Alternatively, a caller may pass NULL for delegated_inode.  This may
+ * be appropriate for callers that expect the underlying filesystem not
+ * to be NFS exported.
+ *
  * The worst of all namespace operations - renaming directory. "Perverted"
  * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
  * Problems:
@@ -4001,19 +4021,39 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
  *         ->i_mutex on parents, which works but leads to some truly excessive
  *         locking].
  */
-static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
-                          struct inode *new_dir, struct dentry *new_dentry)
+int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+               struct inode *new_dir, struct dentry *new_dentry,
+               struct inode **delegated_inode)
 {
-        int error = 0;
+        int error;
+        bool is_dir = d_is_dir(old_dentry);
+        const unsigned char *old_name;
+        struct inode *source = old_dentry->d_inode;
         struct inode *target = new_dentry->d_inode;
-        unsigned max_links = new_dir->i_sb->s_max_links;
+
+        if (source == target)
+                return 0;
+
+        error = may_delete(old_dir, old_dentry, is_dir);
+        if (error)
+                return error;
+
+        if (!target)
+                error = may_create(new_dir, new_dentry);
+        else
+                error = may_delete(new_dir, new_dentry, is_dir);
+        if (error)
+                return error;
+
+        if (!old_dir->i_op->rename)
+                return -EPERM;
 
         /*
          * If we are going to change the parent - check write permissions,
          * we'll need to flip '..'.
          */
-        if (new_dir != old_dir) {
-                error = inode_permission(old_dentry->d_inode, MAY_WRITE);
+        if (is_dir && new_dir != old_dir) {
+                error = inode_permission(source, MAY_WRITE);
                 if (error)
                         return error;
         }
@@ -4022,134 +4062,57 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
         if (error)
                 return error;
 
+        old_name = fsnotify_oldname_init(old_dentry->d_name.name);
         dget(new_dentry);
-        if (target)
+        if (!is_dir)
+                lock_two_nondirectories(source, target);
+        else if (target)
                 mutex_lock(&target->i_mutex);
 
         error = -EBUSY;
         if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
                 goto out;
 
-        error = -EMLINK;
-        if (max_links && !target && new_dir != old_dir &&
-            new_dir->i_nlink >= max_links)
-                goto out;
-
-        if (target)
-                shrink_dcache_parent(new_dentry);
-        error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
-        if (error)
-                goto out;
-
-        if (target) {
-                target->i_flags |= S_DEAD;
-                dont_mount(new_dentry);
-        }
-        if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
-                d_move(old_dentry, new_dentry);
-out:
-        if (target)
-                mutex_unlock(&target->i_mutex);
-        dput(new_dentry);
-        return error;
-}
-
-static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
-                            struct inode *new_dir, struct dentry *new_dentry,
-                            struct inode **delegated_inode)
-{
-        struct inode *target = new_dentry->d_inode;
-        struct inode *source = old_dentry->d_inode;
-        int error;
-
-        error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
-        if (error)
-                return error;
-
-        dget(new_dentry);
-        lock_two_nondirectories(source, target);
+        if (is_dir) {
+                unsigned max_links = new_dir->i_sb->s_max_links;
 
-        error = -EBUSY;
-        if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
-                goto out;
+                error = -EMLINK;
+                if (max_links && !target && new_dir != old_dir &&
+                    new_dir->i_nlink >= max_links)
+                        goto out;
 
-        error = try_break_deleg(source, delegated_inode);
-        if (error)
-                goto out;
-        if (target) {
-                error = try_break_deleg(target, delegated_inode);
+                if (target)
+                        shrink_dcache_parent(new_dentry);
+        } else {
+                error = try_break_deleg(source, delegated_inode);
                 if (error)
                         goto out;
+                if (target) {
+                        error = try_break_deleg(target, delegated_inode);
+                        if (error)
+                                goto out;
+                }
         }
         error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
         if (error)
                 goto out;
 
-        if (target)
+        if (target) {
+                if (is_dir)
+                        target->i_flags |= S_DEAD;
                 dont_mount(new_dentry);
+        }
         if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
                 d_move(old_dentry, new_dentry);
 out:
-        unlock_two_nondirectories(source, target);
+        if (!is_dir)
+                unlock_two_nondirectories(source, target);
+        else if (target)
+                mutex_unlock(&target->i_mutex);
         dput(new_dentry);
-        return error;
-}
-
-/**
- * vfs_rename - rename a filesystem object
- * @old_dir:    parent of source
- * @old_dentry: source
- * @new_dir:    parent of destination
- * @new_dentry: destination
- * @delegated_inode: returns an inode needing a delegation break
- *
- * The caller must hold multiple mutexes--see lock_rename()).
- *
- * If vfs_rename discovers a delegation in need of breaking at either
- * the source or destination, it will return -EWOULDBLOCK and return a
- * reference to the inode in delegated_inode.  The caller should then
- * break the delegation and retry.  Because breaking a delegation may
- * take a long time, the caller should drop all locks before doing
- * so.
- *
- * Alternatively, a caller may pass NULL for delegated_inode.  This may
- * be appropriate for callers that expect the underlying filesystem not
- * to be NFS exported.
- */
-int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
-               struct inode *new_dir, struct dentry *new_dentry,
-               struct inode **delegated_inode)
-{
-        int error;
-        int is_dir = d_is_dir(old_dentry);
-        const unsigned char *old_name;
-
-        if (old_dentry->d_inode == new_dentry->d_inode)
-                return 0;
- 
-        error = may_delete(old_dir, old_dentry, is_dir);
-        if (error)
-                return error;
-
-        if (!new_dentry->d_inode)
-                error = may_create(new_dir, new_dentry);
-        else
-                error = may_delete(new_dir, new_dentry, is_dir);
-        if (error)
-                return error;
-
-        if (!old_dir->i_op->rename)
-                return -EPERM;
-
-        old_name = fsnotify_oldname_init(old_dentry->d_name.name);
-
-        if (is_dir)
-                error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
-        else
-                error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode);
         if (!error)
                 fsnotify_move(old_dir, new_dir, old_name, is_dir,
-                              new_dentry->d_inode, old_dentry);
+                              target, old_dentry);
         fsnotify_oldname_free(old_name);
 
         return error;