Commit 9a08c352 authored by James Bottomley's avatar James Bottomley
Browse files

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: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: default avatarJan Kara <jack@suse.cz>
parent f55532a0

fs/internal.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ extern long do_handle_open(int mountdirfd, 
			   struct file_handle __user *ufh, int open_flag);

extern int open_check_o_direct(struct file *f);

extern int vfs_open(const struct path *, struct file *, const struct cred *);

extern struct file *filp_clone_open(struct file *);



/*

 * inode.c

fs/open.c

+20 −0
Original line number Diff line number Diff line
@@ -1002,6 +1002,26 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, 
}

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;

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