libfs: Move shmem_exchange to simple_rename_exchange

Move shmem_exchange and make it available to other callers. Suggested-by: Miklos Szeredi <[email protected]> Signed-off-by: Lorenz Bauer <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Miklos Szeredi <[email protected]> Cc: Al Viro <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
niw · Nov 3, 2021 · 6429e46 · 6429e46
1 parent 92f6248
commit 6429e46
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Showing 3 changed files with 27 additions and 23 deletions.
diff --git a/fs/libfs.c b/fs/libfs.c
@@ -448,6 +448,30 @@ int simple_rmdir(struct inode *dir, struct dentry *dentry)
 }
 EXPORT_SYMBOL(simple_rmdir);
 
+int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
+			   struct inode *new_dir, struct dentry *new_dentry)
+{
+	bool old_is_dir = d_is_dir(old_dentry);
+	bool new_is_dir = d_is_dir(new_dentry);
+
+	if (old_dir != new_dir && old_is_dir != new_is_dir) {
+		if (old_is_dir) {
+			drop_nlink(old_dir);
+			inc_nlink(new_dir);
+		} else {
+			drop_nlink(new_dir);
+			inc_nlink(old_dir);
+		}
+	}
+	old_dir->i_ctime = old_dir->i_mtime =
+	new_dir->i_ctime = new_dir->i_mtime =
+	d_inode(old_dentry)->i_ctime =
+	d_inode(new_dentry)->i_ctime = current_time(old_dir);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(simple_rename_exchange);
+
 int simple_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 		  struct dentry *old_dentry, struct inode *new_dir,
 		  struct dentry *new_dentry, unsigned int flags)

diff --git a/include/linux/fs.h b/include/linux/fs.h
@@ -3383,6 +3383,8 @@ extern int simple_open(struct inode *inode, struct file *file);
 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
 extern int simple_unlink(struct inode *, struct dentry *);
 extern int simple_rmdir(struct inode *, struct dentry *);
+extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
+				  struct inode *new_dir, struct dentry *new_dentry);
 extern int simple_rename(struct user_namespace *, struct inode *,
 			 struct dentry *, struct inode *, struct dentry *,
 			 unsigned int);

diff --git a/mm/shmem.c b/mm/shmem.c
@@ -2947,28 +2947,6 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry)
 	return shmem_unlink(dir, dentry);
 }
 
-static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry)
-{
-	bool old_is_dir = d_is_dir(old_dentry);
-	bool new_is_dir = d_is_dir(new_dentry);
-
-	if (old_dir != new_dir && old_is_dir != new_is_dir) {
-		if (old_is_dir) {
-			drop_nlink(old_dir);
-			inc_nlink(new_dir);
-		} else {
-			drop_nlink(new_dir);
-			inc_nlink(old_dir);
-		}
-	}
-	old_dir->i_ctime = old_dir->i_mtime =
-	new_dir->i_ctime = new_dir->i_mtime =
-	d_inode(old_dentry)->i_ctime =
-	d_inode(new_dentry)->i_ctime = current_time(old_dir);
-
-	return 0;
-}
-
 static int shmem_whiteout(struct user_namespace *mnt_userns,
 			  struct inode *old_dir, struct dentry *old_dentry)
 {
@@ -3014,7 +2992,7 @@ static int shmem_rename2(struct user_namespace *mnt_userns,
 		return -EINVAL;
 
 	if (flags & RENAME_EXCHANGE)
-		return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry);
+		return simple_rename_exchange(old_dir, old_dentry, new_dir, new_dentry);
 
 	if (!simple_empty(new_dentry))
 		return -ENOTEMPTY;