1 files changed, 45 insertions, 2 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 65c2be22b601..7c30e3a62baf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1506,6 +1506,11 @@ int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
  * to have different dirent layouts depending on the binary type.
  */
 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
+struct dir_context {
+	const filldir_t actor;
+	loff_t pos;
+};
+
 struct block_device_operations;
 
 /* These macros are for out of kernel modules to test that
@@ -1521,7 +1526,7 @@ struct file_operations {
 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
-	int (*readdir) (struct file *, void *, filldir_t);
+	int (*iterate) (struct file *, struct dir_context *);
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
@@ -2494,6 +2499,7 @@ loff_t inode_get_bytes(struct inode *inode);
 void inode_set_bytes(struct inode *inode, loff_t bytes);
 
 extern int vfs_readdir(struct file *, filldir_t, void *);
+extern int iterate_dir(struct file *, struct dir_context *);
 
 extern int vfs_stat(const char __user *, struct kstat *);
 extern int vfs_lstat(const char __user *, struct kstat *);
@@ -2524,7 +2530,7 @@ extern void iterate_supers_type(struct file_system_type *,
 extern int dcache_dir_open(struct inode *, struct file *);
 extern int dcache_dir_close(struct inode *, struct file *);
 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
-extern int dcache_readdir(struct file *, void *, filldir_t);
+extern int dcache_readdir(struct file *, struct dir_context *);
 extern int simple_setattr(struct dentry *, struct iattr *);
 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 extern int simple_statfs(struct dentry *, struct kstatfs *);
@@ -2688,4 +2694,41 @@ static inline void inode_has_no_xattr(struct inode *inode)
 		inode->i_flags |= S_NOSEC;
 }
 
+static inline bool dir_emit(struct dir_context *ctx,
+			    const char *name, int namelen,
+			    u64 ino, unsigned type)
+{
+	return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
+}
+static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
+{
+	return ctx->actor(ctx, ".", 1, ctx->pos,
+			  file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
+}
+static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
+{
+	return ctx->actor(ctx, "..", 2, ctx->pos,
+			  parent_ino(file->f_path.dentry), DT_DIR) == 0;
+}
+static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
+{
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(file, ctx))
+			return false;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit_dotdot(file, ctx))
+			return false;
+		ctx->pos = 2;
+	}
+	return true;
+}
+static inline bool dir_relax(struct inode *inode)
+{
+	mutex_unlock(&inode->i_mutex);
+	mutex_lock(&inode->i_mutex);
+	return !IS_DEADDIR(inode);
+}
+
 #endif /* _LINUX_FS_H */