aha/fs/nfsctl.c
Jan Blunck 4ac9137858 Embed a struct path into struct nameidata instead of nd->{dentry,mnt}
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:13:33 -08:00

112 lines
2.4 KiB
C

/*
* fs/nfsctl.c
*
* This should eventually move to userland.
*
*/
#include <linux/types.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/syscall.h>
#include <linux/linkage.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
/*
* open a file on nfsd fs
*/
static struct file *do_open(char *name, int flags)
{
struct nameidata nd;
struct vfsmount *mnt;
int error;
mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
if (IS_ERR(mnt))
return (struct file *)mnt;
error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
mntput(mnt); /* drop do_kern_mount reference */
if (error)
return ERR_PTR(error);
if (flags == O_RDWR)
error = may_open(&nd,MAY_READ|MAY_WRITE,FMODE_READ|FMODE_WRITE);
else
error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
if (!error)
return dentry_open(nd.path.dentry, nd.path.mnt, flags);
path_release(&nd);
return ERR_PTR(error);
}
static struct {
char *name; int wsize; int rsize;
} map[] = {
[NFSCTL_SVC] = {
.name = ".svc",
.wsize = sizeof(struct nfsctl_svc)
},
[NFSCTL_ADDCLIENT] = {
.name = ".add",
.wsize = sizeof(struct nfsctl_client)
},
[NFSCTL_DELCLIENT] = {
.name = ".del",
.wsize = sizeof(struct nfsctl_client)
},
[NFSCTL_EXPORT] = {
.name = ".export",
.wsize = sizeof(struct nfsctl_export)
},
[NFSCTL_UNEXPORT] = {
.name = ".unexport",
.wsize = sizeof(struct nfsctl_export)
},
[NFSCTL_GETFD] = {
.name = ".getfd",
.wsize = sizeof(struct nfsctl_fdparm),
.rsize = NFS_FHSIZE
},
[NFSCTL_GETFS] = {
.name = ".getfs",
.wsize = sizeof(struct nfsctl_fsparm),
.rsize = sizeof(struct knfsd_fh)
},
};
long
asmlinkage sys_nfsservctl(int cmd, struct nfsctl_arg __user *arg, void __user *res)
{
struct file *file;
void __user *p = &arg->u;
int version;
int err;
if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
return -EFAULT;
if (version != NFSCTL_VERSION)
return -EINVAL;
if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
return -EINVAL;
file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
if (IS_ERR(file))
return PTR_ERR(file);
err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
if (err >= 0 && map[cmd].rsize)
err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
if (err >= 0)
err = 0;
fput(file);
return err;
}