137488Smckusick /* 237488Smckusick * Copyright (c) 1989 The Regents of the University of California. 337488Smckusick * All rights reserved. 437488Smckusick * 537488Smckusick * Redistribution and use in source and binary forms are permitted 637488Smckusick * provided that the above copyright notice and this paragraph are 737488Smckusick * duplicated in all such forms and that any documentation, 837488Smckusick * advertising materials, and other materials related to such 937488Smckusick * distribution and use acknowledge that the software was developed 1037488Smckusick * by the University of California, Berkeley. The name of the 1137488Smckusick * University may not be used to endorse or promote products derived 1237488Smckusick * from this software without specific prior written permission. 1337488Smckusick * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 1437488Smckusick * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 1537488Smckusick * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 1637488Smckusick * 17*38258Smckusick * @(#)vfs_subr.c 7.2 (Berkeley) 06/07/89 1837488Smckusick */ 1937488Smckusick 2037488Smckusick /* 2137488Smckusick * External virtual filesystem routines 2237488Smckusick */ 2337488Smckusick 2437488Smckusick #include "param.h" 2537488Smckusick #include "mount.h" 2637488Smckusick #include "time.h" 2737488Smckusick #include "vnode.h" 2837488Smckusick #include "errno.h" 2937488Smckusick 3037488Smckusick /* 3137488Smckusick * Add a new mount point to the list of mounted filesystems. 3237488Smckusick * Lock the filesystem so that namei will not cross into the 3337488Smckusick * the tree below the covered vnode. 3437488Smckusick */ 3537488Smckusick vfs_add(mountedvp, mp, flags) 3637488Smckusick register struct vnode *mountedvp; 3737488Smckusick register struct mount *mp; 3837488Smckusick int flags; 3937488Smckusick { 4037488Smckusick register int error; 4137488Smckusick 4237488Smckusick error = vfs_lock(mp); 4337488Smckusick if (error) 4437488Smckusick return (error); 4537488Smckusick if (mountedvp == (struct vnode *)0) { 4637488Smckusick /* 4737488Smckusick * We are mounting the root filesystem. 4837488Smckusick */ 4937488Smckusick rootfs = mp; 5037488Smckusick mp->m_next = mp; 5137488Smckusick mp->m_prev = mp; 5237488Smckusick } else { 5337488Smckusick if (mountedvp->v_mountedhere != (struct mount *)0) { 5437488Smckusick vfs_unlock(mp); 5537488Smckusick return(EBUSY); 5637488Smckusick } 5737488Smckusick /* 5837488Smckusick * Put the new filesystem on the mount list after root. 5937488Smckusick */ 6037488Smckusick mp->m_next = rootfs->m_next; 6137488Smckusick mp->m_prev = rootfs; 6237488Smckusick rootfs->m_next = mp; 6337488Smckusick mp->m_next->m_prev = mp; 6437488Smckusick mountedvp->v_mountedhere = mp; 6537488Smckusick } 6637488Smckusick mp->m_vnodecovered = mountedvp; 6737488Smckusick if (flags & M_RDONLY) { 6837488Smckusick mp->m_flag |= M_RDONLY; 6937488Smckusick } else { 7037488Smckusick mp->m_flag &= ~M_RDONLY; 7137488Smckusick } 7237488Smckusick if (flags & M_NOSUID) { 7337488Smckusick mp->m_flag |= M_NOSUID; 7437488Smckusick } else { 7537488Smckusick mp->m_flag &= ~M_NOSUID; 7637488Smckusick } 7737488Smckusick return (0); 7837488Smckusick } 7937488Smckusick 8037488Smckusick /* 8137488Smckusick * Remove a mount point from the list of mounted filesystems. 8237488Smckusick * Unmount of the root is illegal. 8337488Smckusick */ 8437488Smckusick void 8537488Smckusick vfs_remove(mp) 8637488Smckusick register struct mount *mp; 8737488Smckusick { 8837488Smckusick 8937488Smckusick if (mp == rootfs) 9037488Smckusick panic("vfs_remove: unmounting root"); 9137488Smckusick mp->m_prev->m_next = mp->m_next; 9237488Smckusick mp->m_next->m_prev = mp->m_prev; 9337488Smckusick mp->m_vnodecovered->v_mountedhere = (struct mount *)0; 9437488Smckusick vfs_unlock(mp); 9537488Smckusick } 9637488Smckusick 9737488Smckusick /* 9837488Smckusick * Lock a filesystem. 9937488Smckusick * Used to prevent access to it while mounting and unmounting. 10037488Smckusick */ 10137488Smckusick vfs_lock(mp) 10237488Smckusick register struct mount *mp; 10337488Smckusick { 10437488Smckusick 10537488Smckusick if (mp->m_flag & M_MLOCK) 10637488Smckusick return (EBUSY); 10737488Smckusick mp->m_flag |= M_MLOCK; 10837488Smckusick return (0); 10937488Smckusick } 11037488Smckusick 11137488Smckusick /* 11237488Smckusick * Unlock a locked filesystem. 11337488Smckusick * Panic if filesystem is not locked. 11437488Smckusick */ 11537488Smckusick void 11637488Smckusick vfs_unlock(mp) 11737488Smckusick register struct mount *mp; 11837488Smckusick { 11937488Smckusick 12037488Smckusick if ((mp->m_flag & M_MLOCK) == 0) 12137488Smckusick panic("vfs_unlock: locked fs"); 12237488Smckusick mp->m_flag &= ~M_MLOCK; 12337488Smckusick if (mp->m_flag & M_MWAIT) { 12437488Smckusick mp->m_flag &= ~M_MWAIT; 12537488Smckusick wakeup((caddr_t)mp); 12637488Smckusick } 12737488Smckusick } 12837488Smckusick 12937488Smckusick /* 13037488Smckusick * Lookup a mount point by filesystem identifier. 13137488Smckusick */ 13237488Smckusick struct mount * 13337488Smckusick getvfs(fsid) 13437488Smckusick fsid_t *fsid; 13537488Smckusick { 13637488Smckusick register struct mount *mp; 13737488Smckusick 13837488Smckusick for (mp = rootfs; mp; mp = mp->m_next) { 13937488Smckusick if (mp->m_fsid.val[0] == fsid->val[0] && 14037488Smckusick mp->m_fsid.val[1] == fsid->val[1]) { 14137488Smckusick break; 14237488Smckusick } 14337488Smckusick } 14437488Smckusick return (mp); 14537488Smckusick } 14637488Smckusick 14737488Smckusick /* 14837488Smckusick * Set vnode attributes to VNOVAL 14937488Smckusick */ 15037488Smckusick void vattr_null(vap) 15137488Smckusick register struct vattr *vap; 15237488Smckusick { 15337488Smckusick 15437488Smckusick vap->va_type = VNON; 15537488Smckusick vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid = 15637488Smckusick vap->va_fsid = vap->va_fileid = vap->va_size = 15737488Smckusick vap->va_size1 = vap->va_blocksize = vap->va_rdev = 15837488Smckusick vap->va_bytes = vap->va_bytes1 = 15937488Smckusick vap->va_atime.tv_sec = vap->va_atime.tv_usec = 16037488Smckusick vap->va_mtime.tv_sec = vap->va_mtime.tv_usec = 161*38258Smckusick vap->va_ctime.tv_sec = vap->va_ctime.tv_usec = 162*38258Smckusick vap->va_flags = vap->va_gen = VNOVAL; 16337488Smckusick } 164