VOP_LINK(9) MidnightBSD Kernel Developer’s Manual VOP_LINK(9)
NAME
VOP_LINK — create a new name for a file
SYNOPSIS
#include <sys/param.h>
#include <sys/vnode.h>
int
VOP_LINK(struct vnode *dvp, struct vnode *vp, struct componentname *cnp);
DESCRIPTION
This links a new name in the specified directory to an existing file.
Its arguments are:
dvp
The vnode of the directory.
vp
The vnode of the file to be linked.
cnp
Pathname information about the file.
The pathname info should not be released on exit because it is done by the caller. The directory and file vnodes should not be released on exit.
LOCKS
VOP_LINK() expects the directory and file vnodes to be locked on entry and will leave the vnodes locked on return.
RETURN VALUES
Zero is returned if the file was linked successfully, otherwise an error is returned.
PSEUDOCODE
int
vop_link(struct vnode *dvp, struct vnode *vp, struct componentname
*cnp)
{
int error = 0;
if (vp->v_mount != dvp->v_mount)
|
return (EXDEV); |
if (vp would have too many links)
|
return (EMLINK); |
if (vp is immutable)
|
return (EPERM); |
/*
* Increment link count of vp and write back the on-disc version of
it.
*/
...;
if (!error) {
|
/* |
|
|
* Add the new name to the directory. |
|
|
*/ |
|
|
...; |
}
return error;
}
ERRORS
[EMLINK]
The file has too many links.
[EPERM]
The file is immutable.
[EXDEV]
A hard link is not possible between different file systems.
SEE ALSO
vn_lock(9), vnode(9)
AUTHORS
This manual page was originally written by Doug Rabson.
MidnightBSD 0.3 July 24, 1996 MidnightBSD 0.3