Commit 0d7a8555 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

vfs: add RENAME_WHITEOUT 



This adds a new RENAME_WHITEOUT flag.  This flag makes rename() create a
whiteout of source.  The whiteout creation is atomic relative to the
rename.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent 787fb6bc

fs/namei.c

+6 −2
Original line number Diff line number Diff line
@@ -4209,12 +4209,16 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, 
	bool should_retry = false;

	int error;



	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))

	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))

		return -EINVAL;



	if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE))

	if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) &&

	    (flags & RENAME_EXCHANGE))

		return -EINVAL;



	if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))

		return -EPERM;



retry:

	from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);

	if (IS_ERR(from)) {

include/uapi/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 


#define RENAME_NOREPLACE	(1 << 0)	/* Don't overwrite target */

#define RENAME_EXCHANGE		(1 << 1)	/* Exchange source and dest */

#define RENAME_WHITEOUT		(1 << 2)	/* Whiteout source */



struct fstrim_range {

	__u64 start;