better fix for loop if unmount fails; clear signal and wait for another

[unix-history] / usr / src / sys / ufs / mfs / mfs_vfsops.c

/*
* Copyright (c) 1989, 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
*      @(#)mfs_vfsops.c        7.16 (Berkeley) %G%
*/

#include "param.h"
#include "time.h"
#include "kernel.h"
#include "user.h"
#include "proc.h"
#include "buf.h"
#include "mount.h"
#include "vnode.h"
#include "../ufs/quota.h"
#include "../ufs/inode.h"
#include "../ufs/ufsmount.h"
#include "../ufs/mfsnode.h"
#include "../ufs/fs.h"

extern struct vnodeops mfs_vnodeops;

/*
* mfs vfs operations.
*/
int mfs_mount();
int mfs_start();
int ufs_unmount();
int ufs_root();
int ufs_quotactl();
int mfs_statfs();
int ufs_sync();
int ufs_fhtovp();
int ufs_vptofh();
int mfs_init();

struct vfsops mfs_vfsops = {
       mfs_mount,
       mfs_start,
       ufs_unmount,
       ufs_root,
       ufs_quotactl,
       mfs_statfs,
       ufs_sync,
       ufs_fhtovp,
       ufs_vptofh,
       mfs_init,
};

/*
* VFS Operations.
*
* mount system call
*/
/* ARGSUSED */
mfs_mount(mp, path, data, ndp)
       register struct mount *mp;
       char *path;
       caddr_t data;
       struct nameidata *ndp;
{
       struct vnode *devvp;
       struct mfs_args args;
       struct ufsmount *ump;
       register struct fs *fs;
       register struct mfsnode *mfsp;
       static int mfs_minor;
       u_int size;
       int error;

       if (mp->mnt_flag & MNT_UPDATE) {
               ump = VFSTOUFS(mp);
               fs = ump->um_fs;
               if (fs->fs_ronly && (mp->mnt_flag & MNT_RDONLY) == 0)
                       fs->fs_ronly = 0;
               return (0);
       }
       if (error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)))
               return (error);
       error = getnewvnode(VT_MFS, (struct mount *)0, &mfs_vnodeops, &devvp);
       if (error)
               return (error);
       devvp->v_type = VBLK;
       if (checkalias(devvp, makedev(255, mfs_minor++), (struct mount *)0))
               panic("mfs_mount: dup dev");
       mfsp = VTOMFS(devvp);
       mfsp->mfs_baseoff = args.base;
       mfsp->mfs_size = args.size;
       mfsp->mfs_vnode = devvp;
       mfsp->mfs_pid = u.u_procp->p_pid;
       mfsp->mfs_buflist = (struct buf *)0;
       if (error = mountfs(devvp, mp)) {
               mfsp->mfs_buflist = (struct buf *)-1;
               vrele(devvp);
               return (error);
       }
       ump = VFSTOUFS(mp);
       fs = ump->um_fs;
       (void) copyinstr(path, fs->fs_fsmnt, sizeof(fs->fs_fsmnt) - 1, &size);
       bzero(fs->fs_fsmnt + size, sizeof(fs->fs_fsmnt) - size);
       bcopy((caddr_t)fs->fs_fsmnt, (caddr_t)mp->mnt_stat.f_mntonname,
               MNAMELEN);
       (void) copyinstr(args.name, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
               &size);
       bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
       (void) mfs_statfs(mp, &mp->mnt_stat);
       return (0);
}

int     mfs_pri = PWAIT | PCATCH;               /* XXX prob. temp */

/*
* Used to grab the process and keep it in the kernel to service
* memory filesystem I/O requests.
*
* Loop servicing I/O requests.
* Copy the requested data into or out of the memory filesystem
* address space.
*/
/* ARGSUSED */
mfs_start(mp, flags)
       struct mount *mp;
       int flags;
{
       register struct vnode *vp = VFSTOUFS(mp)->um_devvp;
       register struct mfsnode *mfsp = VTOMFS(vp);
       register struct buf *bp;
       register caddr_t base;
       struct proc *p = u.u_procp;
       int error = 0;

       base = mfsp->mfs_baseoff;
       while (mfsp->mfs_buflist != (struct buf *)(-1)) {
               while (bp = mfsp->mfs_buflist) {
                       mfsp->mfs_buflist = bp->av_forw;
                       mfs_doio(bp, base);
                       wakeup((caddr_t)bp);
               }
               /*
                * If a non-ignored signal is received, try to unmount.
                * If that fails, clear the signal (it has been "processed"),
                * otherwise we will loop here, as tsleep will always return
                * EINTR/ERESTART.
                */
               if (error = tsleep((caddr_t)vp, mfs_pri, "mfsidl", 0))
                       if (dounmount(mp, MNT_NOFORCE) != 0)
                               CLRSIG(p, CURSIG(p));
       }
       return (error);
}

/*
* Get file system statistics.
*/
mfs_statfs(mp, sbp)
       struct mount *mp;
       struct statfs *sbp;
{
       int error;

       error = ufs_statfs(mp, sbp);
       sbp->f_type = MOUNT_MFS;
       return (error);
}