diff options
Diffstat (limited to 'sys/miscfs/union/union_vfsops.c')
| -rw-r--r-- | sys/miscfs/union/union_vfsops.c | 485 |
1 files changed, 0 insertions, 485 deletions
diff --git a/sys/miscfs/union/union_vfsops.c b/sys/miscfs/union/union_vfsops.c deleted file mode 100644 index d38f31e..0000000 --- a/sys/miscfs/union/union_vfsops.c +++ /dev/null @@ -1,485 +0,0 @@ -/* - * Copyright (c) 1994, 1995 The Regents of the University of California. - * Copyright (c) 1994, 1995 Jan-Simon Pendry. - * All rights reserved. - * - * This code is derived from software donated to Berkeley by - * Jan-Simon Pendry. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)union_vfsops.c 8.20 (Berkeley) 5/20/95 - * $FreeBSD$ - */ - -/* - * Union Layer - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/kernel.h> -#include <sys/proc.h> -#include <sys/vnode.h> -#include <sys/mount.h> -#include <sys/namei.h> -#include <sys/malloc.h> -#include <sys/filedesc.h> -#include <miscfs/union/union.h> - -static MALLOC_DEFINE(M_UNIONFSMNT, "UNION mount", "UNION mount structure"); - -extern int union_init __P((struct vfsconf *)); -static int union_mount __P((struct mount *mp, char *path, caddr_t data, - struct nameidata *ndp, struct proc *p)); -static int union_root __P((struct mount *mp, struct vnode **vpp)); -static int union_statfs __P((struct mount *mp, struct statfs *sbp, - struct proc *p)); -static int union_unmount __P((struct mount *mp, int mntflags, - struct proc *p)); - -/* - * Mount union filesystem - */ -static int -union_mount(mp, path, data, ndp, p) - struct mount *mp; - char *path; - caddr_t data; - struct nameidata *ndp; - struct proc *p; -{ - int error = 0; - struct union_args args; - struct vnode *lowerrootvp = NULLVP; - struct vnode *upperrootvp = NULLVP; - struct union_mount *um = 0; - struct ucred *cred = 0; - char *cp = 0; - int len; - u_int size; - - UDEBUG(("union_mount(mp = %p)\n", (void *)mp)); - - /* - * Disable clustered write, otherwise system becomes unstable. - */ - mp->mnt_flag |= MNT_NOCLUSTERW; - - /* - * Update is a no-op - */ - if (mp->mnt_flag & MNT_UPDATE) { - /* - * Need to provide. - * 1. a way to convert between rdonly and rdwr mounts. - * 2. support for nfs exports. - */ - error = EOPNOTSUPP; - goto bad; - } - - /* - * Get argument - */ - error = copyin(data, (caddr_t)&args, sizeof(struct union_args)); - if (error) - goto bad; - - /* - * Obtain lower vnode. Vnode is stored in mp->mnt_vnodecovered. - * We need to reference it but not lock it. - */ - - lowerrootvp = mp->mnt_vnodecovered; - VREF(lowerrootvp); - -#if 0 - /* - * Unlock lower node to avoid deadlock. - */ - if (lowerrootvp->v_op == union_vnodeop_p) - VOP_UNLOCK(lowerrootvp, 0, p); -#endif - - /* - * Obtain upper vnode by calling namei() on the path. The - * upperrootvp will be turned referenced but not locked. - */ - NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT, - UIO_USERSPACE, args.target, p); - - error = namei(ndp); - -#if 0 - if (lowerrootvp->v_op == union_vnodeop_p) - vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, p); -#endif - if (error) - goto bad; - - NDFREE(ndp, NDF_ONLY_PNBUF); - upperrootvp = ndp->ni_vp; - vrele(ndp->ni_dvp); - ndp->ni_dvp = NULL; - - UDEBUG(("mount_root UPPERVP %p locked = %d\n", upperrootvp, - VOP_ISLOCKED(upperrootvp, NULL))); - - /* - * Check multi union mount to avoid `lock myself again' panic. - * Also require that it be a directory. - */ - if (upperrootvp == VTOUNION(lowerrootvp)->un_uppervp) { -#ifdef DIAGNOSTIC - printf("union_mount: multi union mount?\n"); -#endif - error = EDEADLK; - goto bad; - } - - if (upperrootvp->v_type != VDIR) { - error = EINVAL; - goto bad; - } - - /* - * Allocate our union_mount structure and populate the fields. - * The vnode references are stored in the union_mount as held, - * unlocked references. Depending on the _BELOW flag, the - * filesystems are viewed in a different order. In effect this - * is the same as providing a mount-under option to the mount - * syscall. - */ - - um = (struct union_mount *) malloc(sizeof(struct union_mount), - M_UNIONFSMNT, M_WAITOK | M_ZERO); - - um->um_op = args.mntflags & UNMNT_OPMASK; - - switch (um->um_op) { - case UNMNT_ABOVE: - um->um_lowervp = lowerrootvp; - um->um_uppervp = upperrootvp; - upperrootvp = NULL; - lowerrootvp = NULL; - break; - - case UNMNT_BELOW: - um->um_lowervp = upperrootvp; - um->um_uppervp = lowerrootvp; - upperrootvp = NULL; - lowerrootvp = NULL; - break; - - case UNMNT_REPLACE: - vrele(lowerrootvp); - lowerrootvp = NULL; - um->um_uppervp = upperrootvp; - um->um_lowervp = lowerrootvp; - upperrootvp = NULL; - break; - - default: - error = EINVAL; - goto bad; - } - - /* - * Unless the mount is readonly, ensure that the top layer - * supports whiteout operations - */ - if ((mp->mnt_flag & MNT_RDONLY) == 0) { - error = VOP_WHITEOUT(um->um_uppervp, NULL, LOOKUP); - if (error) - goto bad; - } - - um->um_cred = p->p_ucred; - crhold(um->um_cred); - um->um_cmode = UN_DIRMODE &~ p->p_fd->fd_cmask; - - /* - * Depending on what you think the MNT_LOCAL flag might mean, - * you may want the && to be || on the conditional below. - * At the moment it has been defined that the filesystem is - * only local if it is all local, ie the MNT_LOCAL flag implies - * that the entire namespace is local. If you think the MNT_LOCAL - * flag implies that some of the files might be stored locally - * then you will want to change the conditional. - */ - if (um->um_op == UNMNT_ABOVE) { - if (((um->um_lowervp == NULLVP) || - (um->um_lowervp->v_mount->mnt_flag & MNT_LOCAL)) && - (um->um_uppervp->v_mount->mnt_flag & MNT_LOCAL)) - mp->mnt_flag |= MNT_LOCAL; - } - - /* - * Copy in the upper layer's RDONLY flag. This is for the benefit - * of lookup() which explicitly checks the flag, rather than asking - * the filesystem for its own opinion. This means, that an update - * mount of the underlying filesystem to go from rdonly to rdwr - * will leave the unioned view as read-only. - */ - mp->mnt_flag |= (um->um_uppervp->v_mount->mnt_flag & MNT_RDONLY); - - mp->mnt_data = (qaddr_t) um; - vfs_getnewfsid(mp); - - switch (um->um_op) { - case UNMNT_ABOVE: - cp = "<above>:"; - break; - case UNMNT_BELOW: - cp = "<below>:"; - break; - case UNMNT_REPLACE: - cp = ""; - break; - } - len = strlen(cp); - bcopy(cp, mp->mnt_stat.f_mntfromname, len); - - cp = mp->mnt_stat.f_mntfromname + len; - len = MNAMELEN - len; - - (void) copyinstr(args.target, cp, len - 1, &size); - bzero(cp + size, len - size); - - (void)union_statfs(mp, &mp->mnt_stat, p); - - UDEBUG(("union_mount: from %s, on %s\n", - mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname)); - return (0); - -bad: - if (um) { - if (um->um_uppervp) - vrele(um->um_uppervp); - if (um->um_lowervp) - vrele(um->um_lowervp); - /* XXX other fields */ - free(um, M_UNIONFSMNT); - } - if (cred) - crfree(cred); - if (upperrootvp) - vrele(upperrootvp); - if (lowerrootvp) - vrele(lowerrootvp); - return (error); -} - -/* - * Free reference to union layer - */ -static int -union_unmount(mp, mntflags, p) - struct mount *mp; - int mntflags; - struct proc *p; -{ - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - int error; - int freeing; - int flags = 0; - - UDEBUG(("union_unmount(mp = %p)\n", (void *)mp)); - - if (mntflags & MNT_FORCE) - flags |= FORCECLOSE; - - /* - * Keep flushing vnodes from the mount list. - * This is needed because of the un_pvp held - * reference to the parent vnode. - * If more vnodes have been freed on a given pass, - * the try again. The loop will iterate at most - * (d) times, where (d) is the maximum tree depth - * in the filesystem. - */ - for (freeing = 0; (error = vflush(mp, 0, flags)) != 0;) { - struct vnode *vp; - int n; - - /* count #vnodes held on mount list */ - n = 0; - LIST_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) - n++; - - /* if this is unchanged then stop */ - if (n == freeing) - break; - - /* otherwise try once more time */ - freeing = n; - } - - /* If the most recent vflush failed, the filesystem is still busy. */ - if (error) - return (error); - - /* - * Discard references to upper and lower target vnodes. - */ - if (um->um_lowervp) - vrele(um->um_lowervp); - vrele(um->um_uppervp); - crfree(um->um_cred); - /* - * Finally, throw away the union_mount structure - */ - free(mp->mnt_data, M_UNIONFSMNT); /* XXX */ - mp->mnt_data = 0; - return (0); -} - -static int -union_root(mp, vpp) - struct mount *mp; - struct vnode **vpp; -{ - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - int error; - - /* - * Supply an unlocked reference to um_uppervp and to um_lowervp. It - * is possible for um_uppervp to be locked without the associated - * root union_node being locked. We let union_allocvp() deal with - * it. - */ - UDEBUG(("union_root UPPERVP %p locked = %d\n", um->um_uppervp, - VOP_ISLOCKED(um->um_uppervp, NULL))); - - VREF(um->um_uppervp); - if (um->um_lowervp) - VREF(um->um_lowervp); - - error = union_allocvp(vpp, mp, NULLVP, NULLVP, NULL, - um->um_uppervp, um->um_lowervp, 1); - UDEBUG(("error %d\n", error)); - UDEBUG(("union_root2 UPPERVP %p locked = %d\n", um->um_uppervp, - VOP_ISLOCKED(um->um_uppervp, NULL))); - - return (error); -} - -static int -union_statfs(mp, sbp, p) - struct mount *mp; - struct statfs *sbp; - struct proc *p; -{ - int error; - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - struct statfs mstat; - int lbsize; - - UDEBUG(("union_statfs(mp = %p, lvp = %p, uvp = %p)\n", - (void *)mp, (void *)um->um_lowervp, (void *)um->um_uppervp)); - - bzero(&mstat, sizeof(mstat)); - - if (um->um_lowervp) { - error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p); - if (error) - return (error); - } - - /* now copy across the "interesting" information and fake the rest */ -#if 0 - sbp->f_type = mstat.f_type; - sbp->f_flags = mstat.f_flags; - sbp->f_bsize = mstat.f_bsize; - sbp->f_iosize = mstat.f_iosize; -#endif - lbsize = mstat.f_bsize; - sbp->f_blocks = mstat.f_blocks; - sbp->f_bfree = mstat.f_bfree; - sbp->f_bavail = mstat.f_bavail; - sbp->f_files = mstat.f_files; - sbp->f_ffree = mstat.f_ffree; - - error = VFS_STATFS(um->um_uppervp->v_mount, &mstat, p); - if (error) - return (error); - - sbp->f_flags = mstat.f_flags; - sbp->f_bsize = mstat.f_bsize; - sbp->f_iosize = mstat.f_iosize; - - /* - * if the lower and upper blocksizes differ, then frig the - * block counts so that the sizes reported by df make some - * kind of sense. none of this makes sense though. - */ - - if (mstat.f_bsize != lbsize) - sbp->f_blocks = ((off_t) sbp->f_blocks * lbsize) / mstat.f_bsize; - - /* - * The "total" fields count total resources in all layers, - * the "free" fields count only those resources which are - * free in the upper layer (since only the upper layer - * is writeable). - */ - sbp->f_blocks += mstat.f_blocks; - sbp->f_bfree = mstat.f_bfree; - sbp->f_bavail = mstat.f_bavail; - sbp->f_files += mstat.f_files; - sbp->f_ffree = mstat.f_ffree; - - 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); -} - -static struct vfsops union_vfsops = { - union_mount, - vfs_stdstart, /* underlying start already done */ - union_unmount, - union_root, - vfs_stdquotactl, - union_statfs, - vfs_stdsync, /* XXX assumes no cached data on union level */ - vfs_stdvget, - vfs_stdfhtovp, - vfs_stdcheckexp, - vfs_stdvptofh, - union_init, - vfs_stduninit, - vfs_stdextattrctl, -}; - -VFS_SET(union_vfsops, union, VFCF_LOOPBACK); |
