cleanups; getnewfsid => vfs_getnewfsid; add fdesc_sysctl

[unix-history] / usr / src / sys / miscfs / fdesc / fdesc_vfsops.c

/*
* Copyright (c) 1992, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* %sccs.include.redist.c%
*
*      @(#)fdesc_vfsops.c      8.6 (Berkeley) %G%
*
* $Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp $
*/

/*
* /dev/fd Filesystem
*/

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/fdesc/fdesc.h>

/*
* Mount the per-process file descriptors (/dev/fd)
*/
int
fdesc_mount(mp, path, data, ndp, p)
       struct mount *mp;
       char *path;
       caddr_t data;
       struct nameidata *ndp;
       struct proc *p;
{
       int error = 0;
       u_int size;
       struct fdescmount *fmp;
       struct vnode *rvp;

       /*
        * Update is a no-op
        */
       if (mp->mnt_flag & MNT_UPDATE)
               return (EOPNOTSUPP);

       error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
       if (error)
               return (error);

       MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
                               M_UFSMNT, M_WAITOK);    /* XXX */
       rvp->v_type = VDIR;
       rvp->v_flag |= VROOT;
       fmp->f_root = rvp;
       /* XXX -- don't mark as local to work around fts() problems */
       /*mp->mnt_flag |= MNT_LOCAL;*/
       mp->mnt_data = (qaddr_t) fmp;
       vfs_getnewfsid(mp);

       (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
       bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
       bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
       bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
       return (0);
}

int
fdesc_start(mp, flags, p)
       struct mount *mp;
       int flags;
       struct proc *p;
{
       return (0);
}

int
fdesc_unmount(mp, mntflags, p)
       struct mount *mp;
       int mntflags;
       struct proc *p;
{
       int error;
       int flags = 0;
       extern int doforce;
       struct vnode *rootvp = VFSTOFDESC(mp)->f_root;

       if (mntflags & MNT_FORCE) {
               /* fdesc can never be rootfs so don't check for it */
               if (!doforce)
                       return (EINVAL);
               flags |= FORCECLOSE;
       }

       /*
        * Clear out buffer cache.  I don't think we
        * ever get anything cached at this level at the
        * moment, but who knows...
        */
       if (rootvp->v_usecount > 1)
               return (EBUSY);
       if (error = vflush(mp, rootvp, flags))
               return (error);

       /*
        * Release reference on underlying root vnode
        */
       vrele(rootvp);
       /*
        * And blow it away for future re-use
        */
       VOP_REVOKE(rootvp, 0);
       /*
        * Finally, throw away the fdescmount structure
        */
       free(mp->mnt_data, M_UFSMNT);   /* XXX */
       mp->mnt_data = 0;

       return (0);
}

int
fdesc_root(mp, vpp)
       struct mount *mp;
       struct vnode **vpp;
{
       struct vnode *vp;

       /*
        * Return locked reference to root.
        */
       vp = VFSTOFDESC(mp)->f_root;
       VREF(vp);
       VOP_LOCK(vp);
       *vpp = vp;
       return (0);
}

int
fdesc_statfs(mp, sbp, p)
       struct mount *mp;
       struct statfs *sbp;
       struct proc *p;
{
       struct filedesc *fdp;
       int lim;
       int i;
       int last;
       int freefd;

       /*
        * Compute number of free file descriptors.
        * [ Strange results will ensue if the open file
        * limit is ever reduced below the current number
        * of open files... ]
        */
       lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
       fdp = p->p_fd;
       last = min(fdp->fd_nfiles, lim);
       freefd = 0;
       for (i = fdp->fd_freefile; i < last; i++)
               if (fdp->fd_ofiles[i] == NULL)
                       freefd++;

       /*
        * Adjust for the fact that the fdesc array may not
        * have been fully allocated yet.
        */
       if (fdp->fd_nfiles < lim)
               freefd += (lim - fdp->fd_nfiles);

       sbp->f_flags = 0;
       sbp->f_bsize = DEV_BSIZE;
       sbp->f_iosize = DEV_BSIZE;
       sbp->f_blocks = 2;              /* 1K to keep df happy */
       sbp->f_bfree = 0;
       sbp->f_bavail = 0;
       sbp->f_files = lim + 1;         /* Allow for "." */
       sbp->f_ffree = freefd;          /* See comments above */
       if (sbp != &mp->mnt_stat) {
               sbp->f_type = mp->mnt_vfc->vfc_typenum;
               bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
               bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
               bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
       }
       return (0);
}

int
fdesc_sync(mp, waitfor)
       struct mount *mp;
       int waitfor;
{

       return (0);
}

struct vfsops fdesc_vfsops = {
       fdesc_mount,
       fdesc_start,
       fdesc_unmount,
       fdesc_root,
       fdesc_quotactl,
       fdesc_statfs,
       fdesc_sync,
       fdesc_vget,
       fdesc_fhtovp,
       fdesc_vptofh,
       fdesc_init,
       fdesc_sysctl,
};