fs: add filp_clone_open API
I need an API that allows me to obtain a clone of the current file
pointer to pass in to an exec handler. I've labelled this as an
internal API because I can't see how it would be useful outside of the
fs subsystem. The use case will be a persistent binfmt_misc handler.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.cz>
diff --git a/fs/open.c b/fs/open.c
index 17cb6b1..bfe6f2b 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1002,6 +1002,26 @@
}
EXPORT_SYMBOL(file_open_root);
+struct file *filp_clone_open(struct file *oldfile)
+{
+ struct file *file;
+ int retval;
+
+ file = get_empty_filp();
+ if (IS_ERR(file))
+ return file;
+
+ file->f_flags = oldfile->f_flags;
+ retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred);
+ if (retval) {
+ put_filp(file);
+ return ERR_PTR(retval);
+ }
+
+ return file;
+}
+EXPORT_SYMBOL(filp_clone_open);
+
long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
{
struct open_flags op;