4ac9137858
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>
113 lines
2.4 KiB
C
113 lines
2.4 KiB
C
/*
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* fs/nfsctl.c
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*
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* This should eventually move to userland.
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*
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*/
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#include <linux/types.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/nfsd/nfsd.h>
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#include <linux/nfsd/syscall.h>
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#include <linux/linkage.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/syscalls.h>
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#include <asm/uaccess.h>
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/*
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* open a file on nfsd fs
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*/
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static struct file *do_open(char *name, int flags)
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{
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struct nameidata nd;
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struct vfsmount *mnt;
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int error;
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mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
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if (IS_ERR(mnt))
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return (struct file *)mnt;
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error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
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mntput(mnt); /* drop do_kern_mount reference */
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if (error)
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return ERR_PTR(error);
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if (flags == O_RDWR)
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error = may_open(&nd,MAY_READ|MAY_WRITE,FMODE_READ|FMODE_WRITE);
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else
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error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
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if (!error)
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return dentry_open(nd.path.dentry, nd.path.mnt, flags);
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path_release(&nd);
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return ERR_PTR(error);
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}
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static struct {
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char *name; int wsize; int rsize;
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} map[] = {
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[NFSCTL_SVC] = {
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.name = ".svc",
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.wsize = sizeof(struct nfsctl_svc)
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},
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[NFSCTL_ADDCLIENT] = {
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.name = ".add",
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.wsize = sizeof(struct nfsctl_client)
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},
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[NFSCTL_DELCLIENT] = {
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.name = ".del",
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.wsize = sizeof(struct nfsctl_client)
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},
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[NFSCTL_EXPORT] = {
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.name = ".export",
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.wsize = sizeof(struct nfsctl_export)
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},
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[NFSCTL_UNEXPORT] = {
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.name = ".unexport",
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.wsize = sizeof(struct nfsctl_export)
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},
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[NFSCTL_GETFD] = {
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.name = ".getfd",
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.wsize = sizeof(struct nfsctl_fdparm),
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.rsize = NFS_FHSIZE
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},
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[NFSCTL_GETFS] = {
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.name = ".getfs",
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.wsize = sizeof(struct nfsctl_fsparm),
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.rsize = sizeof(struct knfsd_fh)
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},
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};
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long
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asmlinkage sys_nfsservctl(int cmd, struct nfsctl_arg __user *arg, void __user *res)
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{
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struct file *file;
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void __user *p = &arg->u;
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int version;
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int err;
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if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
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return -EFAULT;
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if (version != NFSCTL_VERSION)
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return -EINVAL;
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if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
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return -EINVAL;
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file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
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if (IS_ERR(file))
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return PTR_ERR(file);
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err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
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if (err >= 0 && map[cmd].rsize)
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err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
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if (err >= 0)
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err = 0;
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fput(file);
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return err;
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}
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