Commit 37364497 authored by Hongbo Li's avatar Hongbo Li Committed by Gao Xiang
Browse files

fs: Export alloc_empty_backing_file 



There is no need to open nonexistent real files if backing files
couldn't be backed by real files (e.g., EROFS page cache sharing
doesn't need typical real files to open again).

Therefore, we export the alloc_empty_backing_file() helper, allowing
filesystems to dynamically set the backing file without real file
open. This is particularly useful for obtaining the correct @path
and @inode when calling file_user_path() and file_user_inode().

Signed-off-by: default avatarHongbo Li <lihongbo22@huawei.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: default avatarAmir Goldstein <amir73il@gmail.com>
Acked-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 0bd20d8e

fs/file_table.c

+1 −0
Original line number Diff line number Diff line
@@ -308,6 +308,7 @@ struct file *alloc_empty_backing_file(int flags, const struct cred *cred) 
	ff->file.f_mode |= FMODE_BACKING | FMODE_NOACCOUNT;

	return &ff->file;

}

EXPORT_SYMBOL_GPL(alloc_empty_backing_file);



/**

 * file_init_path - initialize a 'struct file' based on path