/* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 * $Id: vfs_subr.c,v 1.181 1999/01/08 17:31:17 eivind Exp $ */ /* * External virtual filesystem routines */ #include "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); static void insmntque __P((struct vnode *vp, struct mount *mp)); static void vclean __P((struct vnode *vp, int flags, struct proc *p)); static void vfree __P((struct vnode *)); static void vgonel __P((struct vnode *vp, struct proc *p)); static unsigned long numvnodes; SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); enum vtype iftovt_tab[16] = { VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, }; int vttoif_tab[9] = { 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, S_IFSOCK, S_IFIFO, S_IFMT, }; static TAILQ_HEAD(freelst, vnode) vnode_free_list; /* vnode free list */ struct tobefreelist vnode_tobefree_list; /* vnode free list */ static u_long wantfreevnodes = 25; SYSCTL_INT(_debug, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); static u_long freevnodes = 0; SYSCTL_INT(_debug, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); int vfs_ioopt = 0; #ifdef ENABLE_VFS_IOOPT SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, ""); #endif struct mntlist mountlist; /* mounted filesystem list */ struct simplelock mountlist_slock; struct simplelock mntvnode_slock; int nfs_mount_type = -1; #ifndef NULL_SIMPLELOCKS static struct simplelock mntid_slock; static struct simplelock vnode_free_list_slock; static struct simplelock spechash_slock; #endif struct nfs_public nfs_pub; /* publicly exported FS */ static vm_zone_t vnode_zone; /* * The workitem queue. */ #define SYNCER_MAXDELAY 32 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ time_t syncdelay = 30; int rushjob; /* number of slots to run ASAP */ static int syncer_delayno = 0; static long syncer_mask; LIST_HEAD(synclist, vnode); static struct synclist *syncer_workitem_pending; int desiredvnodes; SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, &desiredvnodes, 0, ""); static void vfs_free_addrlist __P((struct netexport *nep)); static int vfs_free_netcred __P((struct radix_node *rn, void *w)); static int vfs_hang_addrlist __P((struct mount *mp, struct netexport *nep, struct export_args *argp)); /* * Initialize the vnode management data structures. */ void vntblinit() { desiredvnodes = maxproc + cnt.v_page_count / 4; simple_lock_init(&mntvnode_slock); simple_lock_init(&mntid_slock); simple_lock_init(&spechash_slock); TAILQ_INIT(&vnode_free_list); TAILQ_INIT(&vnode_tobefree_list); simple_lock_init(&vnode_free_list_slock); CIRCLEQ_INIT(&mountlist); vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5); /* * Initialize the filesystem syncer. */ syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, &syncer_mask); syncer_maxdelay = syncer_mask + 1; } /* * Mark a mount point as busy. Used to synchronize access and to delay * unmounting. Interlock is not released on failure. */ int vfs_busy(mp, flags, interlkp, p) struct mount *mp; int flags; struct simplelock *interlkp; struct proc *p; { int lkflags; if (mp->mnt_kern_flag & MNTK_UNMOUNT) { if (flags & LK_NOWAIT) return (ENOENT); mp->mnt_kern_flag |= MNTK_MWAIT; if (interlkp) { simple_unlock(interlkp); } /* * Since all busy locks are shared except the exclusive * lock granted when unmounting, the only place that a * wakeup needs to be done is at the release of the * exclusive lock at the end of dounmount. */ tsleep((caddr_t)mp, PVFS, "vfs_busy", 0); if (interlkp) { simple_lock(interlkp); } return (ENOENT); } lkflags = LK_SHARED | LK_NOPAUSE; if (interlkp) lkflags |= LK_INTERLOCK; if (lockmgr(&mp->mnt_lock, lkflags, interlkp, p)) panic("vfs_busy: unexpected lock failure"); return (0); } /* * Free a busy filesystem. */ void vfs_unbusy(mp, p) struct mount *mp; struct proc *p; { lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, p); } /* * Lookup a filesystem type, and if found allocate and initialize * a mount structure for it. * * Devname is usually updated by mount(8) after booting. */ int vfs_rootmountalloc(fstypename, devname, mpp) char *fstypename; char *devname; struct mount **mpp; { struct proc *p = curproc; /* XXX */ struct vfsconf *vfsp; struct mount *mp; if (fstypename == NULL) return (ENODEV); for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) if (!strcmp(vfsp->vfc_name, fstypename)) break; if (vfsp == NULL) return (ENODEV); mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK); bzero((char *)mp, (u_long)sizeof(struct mount)); lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); (void)vfs_busy(mp, LK_NOWAIT, 0, p); LIST_INIT(&mp->mnt_vnodelist); mp->mnt_vfc = vfsp; mp->mnt_op = vfsp->vfc_vfsops; mp->mnt_flag = MNT_RDONLY; mp->mnt_vnodecovered = NULLVP; vfsp->vfc_refcount++; mp->mnt_stat.f_type = vfsp->vfc_typenum; mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); mp->mnt_stat.f_mntonname[0] = '/'; mp->mnt_stat.f_mntonname[1] = 0; (void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0); *mpp = mp; return (0); } /* * Find an appropriate filesystem to use for the root. If a filesystem * has not been preselected, walk through the list of known filesystems * trying those that have mountroot routines, and try them until one * works or we have tried them all. */ #ifdef notdef /* XXX JH */ int lite2_vfs_mountroot() { struct vfsconf *vfsp; extern int (*lite2_mountroot) __P((void)); int error; if (lite2_mountroot != NULL) return ((*lite2_mountroot)()); for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { if (vfsp->vfc_mountroot == NULL) continue; if ((error = (*vfsp->vfc_mountroot)()) == 0) return (0); printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error); } return (ENODEV); } #endif /* * Lookup a mount point by filesystem identifier. */ struct mount * vfs_getvfs(fsid) fsid_t *fsid; { register struct mount *mp; simple_lock(&mountlist_slock); for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = mp->mnt_list.cqe_next) { if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { simple_unlock(&mountlist_slock); return (mp); } } simple_unlock(&mountlist_slock); return ((struct mount *) 0); } /* * Get a new unique fsid */ void vfs_getnewfsid(mp) struct mount *mp; { static u_short xxxfs_mntid; fsid_t tfsid; int mtype; simple_lock(&mntid_slock); mtype = mp->mnt_vfc->vfc_typenum; mp->mnt_stat.f_fsid.val[0] = makedev(nblkdev + mtype, 0); mp->mnt_stat.f_fsid.val[1] = mtype; if (xxxfs_mntid == 0) ++xxxfs_mntid; tfsid.val[0] = makedev(nblkdev + mtype, xxxfs_mntid); tfsid.val[1] = mtype; if (mountlist.cqh_first != (void *)&mountlist) { while (vfs_getvfs(&tfsid)) { tfsid.val[0]++; xxxfs_mntid++; } } mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; simple_unlock(&mntid_slock); } /* * Set vnode attributes to VNOVAL */ void vattr_null(vap) register struct vattr *vap; { vap->va_type = VNON; vap->va_size = VNOVAL; vap->va_bytes = VNOVAL; vap->va_mode = VNOVAL; vap->va_nlink = VNOVAL; vap->va_uid = VNOVAL; vap->va_gid = VNOVAL; vap->va_fsid = VNOVAL; vap->va_fileid = VNOVAL; vap->va_blocksize = VNOVAL; vap->va_rdev = VNOVAL; vap->va_atime.tv_sec = VNOVAL; vap->va_atime.tv_nsec = VNOVAL; vap->va_mtime.tv_sec = VNOVAL; vap->va_mtime.tv_nsec = VNOVAL; vap->va_ctime.tv_sec = VNOVAL; vap->va_ctime.tv_nsec = VNOVAL; vap->va_flags = VNOVAL; vap->va_gen = VNOVAL; vap->va_vaflags = 0; } /* * Routines having to do with the management of the vnode table. */ extern vop_t **dead_vnodeop_p; /* * Return the next vnode from the free list. */ int getnewvnode(tag, mp, vops, vpp) enum vtagtype tag; struct mount *mp; vop_t **vops; struct vnode **vpp; { int s; struct proc *p = curproc; /* XXX */ struct vnode *vp, *tvp, *nvp; vm_object_t object; TAILQ_HEAD(freelst, vnode) vnode_tmp_list; /* * We take the least recently used vnode from the freelist * if we can get it and it has no cached pages, and no * namecache entries are relative to it. * Otherwise we allocate a new vnode */ s = splbio(); simple_lock(&vnode_free_list_slock); TAILQ_INIT(&vnode_tmp_list); for (vp = TAILQ_FIRST(&vnode_tobefree_list); vp; vp = nvp) { nvp = TAILQ_NEXT(vp, v_freelist); TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist); if (vp->v_flag & VAGE) { TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); } else { TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); } vp->v_flag &= ~(VTBFREE|VAGE); vp->v_flag |= VFREE; if (vp->v_usecount) panic("tobe free vnode isn't"); freevnodes++; } if (wantfreevnodes && freevnodes < wantfreevnodes) { vp = NULL; } else if (!wantfreevnodes && freevnodes <= desiredvnodes) { /* * XXX: this is only here to be backwards compatible */ vp = NULL; } else { for (vp = TAILQ_FIRST(&vnode_free_list); vp; vp = nvp) { nvp = TAILQ_NEXT(vp, v_freelist); if (!simple_lock_try(&vp->v_interlock)) continue; if (vp->v_usecount) panic("free vnode isn't"); object = vp->v_object; if (object && (object->resident_page_count || object->ref_count)) { printf("object inconsistant state: RPC: %d, RC: %d\n", object->resident_page_count, object->ref_count); /* Don't recycle if it's caching some pages */ TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); TAILQ_INSERT_TAIL(&vnode_tmp_list, vp, v_freelist); continue; } else if (LIST_FIRST(&vp->v_cache_src)) { /* Don't recycle if active in the namecache */ simple_unlock(&vp->v_interlock); continue; } else { break; } } } for (tvp = TAILQ_FIRST(&vnode_tmp_list); tvp; tvp = nvp) { nvp = TAILQ_NEXT(tvp, v_freelist); TAILQ_REMOVE(&vnode_tmp_list, tvp, v_freelist); TAILQ_INSERT_TAIL(&vnode_free_list, tvp, v_freelist); simple_unlock(&tvp->v_interlock); } if (vp) { vp->v_flag |= VDOOMED; TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); freevnodes--; simple_unlock(&vnode_free_list_slock); cache_purge(vp); vp->v_lease = NULL; if (vp->v_type != VBAD) { vgonel(vp, p); } else { simple_unlock(&vp->v_interlock); } #ifdef INVARIANTS { int s; if (vp->v_data) panic("cleaned vnode isn't"); s = splbio(); if (vp->v_numoutput) panic("Clean vnode has pending I/O's"); splx(s); } #endif vp->v_flag = 0; vp->v_lastr = 0; vp->v_lastw = 0; vp->v_lasta = 0; vp->v_cstart = 0; vp->v_clen = 0; vp->v_socket = 0; vp->v_writecount = 0; /* XXX */ vp->v_maxio = 0; } else { simple_unlock(&vnode_free_list_slock); vp = (struct vnode *) zalloc(vnode_zone); bzero((char *) vp, sizeof *vp); simple_lock_init(&vp->v_interlock); vp->v_dd = vp; cache_purge(vp); LIST_INIT(&vp->v_cache_src); TAILQ_INIT(&vp->v_cache_dst); numvnodes++; } TAILQ_INIT(&vp->v_cleanblkhd); TAILQ_INIT(&vp->v_dirtyblkhd); vp->v_type = VNON; vp->v_tag = tag; vp->v_op = vops; insmntque(vp, mp); *vpp = vp; vp->v_usecount = 1; vp->v_data = 0; splx(s); vfs_object_create(vp, p, p->p_ucred); return (0); } /* * Move a vnode from one mount queue to another. */ static void insmntque(vp, mp) register struct vnode *vp; register struct mount *mp; { simple_lock(&mntvnode_slock); /* * Delete from old mount point vnode list, if on one. */ if (vp->v_mount != NULL) LIST_REMOVE(vp, v_mntvnodes); /* * Insert into list of vnodes for the new mount point, if available. */ if ((vp->v_mount = mp) == NULL) { simple_unlock(&mntvnode_slock); return; } LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes); simple_unlock(&mntvnode_slock); } /* * Update outstanding I/O count and do wakeup if requested. */ void vwakeup(bp) register struct buf *bp; { register struct vnode *vp; bp->b_flags &= ~B_WRITEINPROG; if ((vp = bp->b_vp)) { vp->v_numoutput--; if (vp->v_numoutput < 0) panic("vwakeup: neg numoutput"); if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) { vp->v_flag &= ~VBWAIT; wakeup((caddr_t) &vp->v_numoutput); } } } /* * Flush out and invalidate all buffers associated with a vnode. * Called with the underlying object locked. */ int vinvalbuf(vp, flags, cred, p, slpflag, slptimeo) register struct vnode *vp; int flags; struct ucred *cred; struct proc *p; int slpflag, slptimeo; { register struct buf *bp; struct buf *nbp, *blist; int s, error; vm_object_t object; if (flags & V_SAVE) { s = splbio(); while (vp->v_numoutput) { vp->v_flag |= VBWAIT; error = tsleep((caddr_t)&vp->v_numoutput, slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); if (error) { splx(s); return (error); } } if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { splx(s); if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p)) != 0) return (error); s = splbio(); if (vp->v_numoutput > 0 || !TAILQ_EMPTY(&vp->v_dirtyblkhd)) panic("vinvalbuf: dirty bufs"); } splx(s); } s = splbio(); for (;;) { blist = TAILQ_FIRST(&vp->v_cleanblkhd); if (!blist) blist = TAILQ_FIRST(&vp->v_dirtyblkhd); if (!blist) break; for (bp = blist; bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (bp->b_flags & B_BUSY) { bp->b_flags |= B_WANTED; error = tsleep((caddr_t) bp, slpflag | (PRIBIO + 4), "vinvalbuf", slptimeo); if (error) { splx(s); return (error); } break; } /* * XXX Since there are no node locks for NFS, I * believe there is a slight chance that a delayed * write will occur while sleeping just above, so * check for it. Note that vfs_bio_awrite expects * buffers to reside on a queue, while VOP_BWRITE and * brelse do not. */ if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && (flags & V_SAVE)) { if (bp->b_vp == vp) { if (bp->b_flags & B_CLUSTEROK) { vfs_bio_awrite(bp); } else { bremfree(bp); bp->b_flags |= (B_BUSY | B_ASYNC); VOP_BWRITE(bp); } } else { bremfree(bp); bp->b_flags |= B_BUSY; (void) VOP_BWRITE(bp); } break; } bremfree(bp); bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF | B_BUSY); bp->b_flags &= ~B_ASYNC; brelse(bp); } } while (vp->v_numoutput > 0) { vp->v_flag |= VBWAIT; tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0); } splx(s); /* * Destroy the copy in the VM cache, too. */ simple_lock(&vp->v_interlock); object = vp->v_object; if (object != NULL) { vm_object_page_remove(object, 0, 0, (flags & V_SAVE) ? TRUE : FALSE); } simple_unlock(&vp->v_interlock); if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd)) panic("vinvalbuf: flush failed"); return (0); } /* * Truncate a file's buffer and pages to a specified length. This * is in lieu of the old vinvalbuf mechanism, which performed unneeded * sync activity. */ int vtruncbuf(vp, cred, p, length, blksize) register struct vnode *vp; struct ucred *cred; struct proc *p; off_t length; int blksize; { register struct buf *bp; struct buf *nbp; int s, anyfreed; int trunclbn; /* * Round up to the *next* lbn. */ trunclbn = (length + blksize - 1) / blksize; s = splbio(); restart: anyfreed = 1; for (;anyfreed;) { anyfreed = 0; for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (bp->b_lblkno >= trunclbn) { if (bp->b_flags & B_BUSY) { bp->b_flags |= B_WANTED; tsleep(bp, PRIBIO + 4, "vtrb1", 0); goto restart; } else { bremfree(bp); bp->b_flags |= (B_BUSY | B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); anyfreed = 1; } if (nbp && (((nbp->b_xflags & B_VNCLEAN) == 0)|| (nbp->b_vp != vp) || (nbp->b_flags & B_DELWRI))) { goto restart; } } } for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (bp->b_lblkno >= trunclbn) { if (bp->b_flags & B_BUSY) { bp->b_flags |= B_WANTED; tsleep(bp, PRIBIO + 4, "vtrb2", 0); goto restart; } else { bremfree(bp); bp->b_flags |= (B_BUSY | B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); anyfreed = 1; } if (nbp && (((nbp->b_xflags & B_VNDIRTY) == 0)|| (nbp->b_vp != vp) || (nbp->b_flags & B_DELWRI) == 0)) { goto restart; } } } } if (length > 0) { restartsync: for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) { if (bp->b_flags & B_BUSY) { bp->b_flags |= B_WANTED; tsleep(bp, PRIBIO, "vtrb3", 0); } else { bremfree(bp); bp->b_flags |= B_BUSY; if (bp->b_vp == vp) { bp->b_flags |= B_ASYNC; } else { bp->b_flags &= ~B_ASYNC; } VOP_BWRITE(bp); } goto restartsync; } } } while (vp->v_numoutput > 0) { vp->v_flag |= VBWAIT; tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0); } splx(s); vnode_pager_setsize(vp, length); return (0); } /* * Associate a buffer with a vnode. */ void bgetvp(vp, bp) register struct vnode *vp; register struct buf *bp; { int s; KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); vhold(vp); bp->b_vp = vp; if (vp->v_type == VBLK || vp->v_type == VCHR) bp->b_dev = vp->v_rdev; else bp->b_dev = NODEV; /* * Insert onto list for new vnode. */ s = splbio(); bp->b_xflags |= B_VNCLEAN; bp->b_xflags &= ~B_VNDIRTY; TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); splx(s); } /* * Disassociate a buffer from a vnode. */ void brelvp(bp) register struct buf *bp; { struct vnode *vp; struct buflists *listheadp; int s; KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); /* * Delete from old vnode list, if on one. */ vp = bp->b_vp; s = splbio(); if (bp->b_xflags & (B_VNDIRTY|B_VNCLEAN)) { if (bp->b_xflags & B_VNDIRTY) listheadp = &vp->v_dirtyblkhd; else listheadp = &vp->v_cleanblkhd; TAILQ_REMOVE(listheadp, bp, b_vnbufs); bp->b_xflags &= ~(B_VNDIRTY|B_VNCLEAN); } if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { vp->v_flag &= ~VONWORKLST; LIST_REMOVE(vp, v_synclist); } splx(s); bp->b_vp = (struct vnode *) 0; vdrop(vp); } /* * The workitem queue. * * It is useful to delay writes of file data and filesystem metadata * for tens of seconds so that quickly created and deleted files need * not waste disk bandwidth being created and removed. To realize this, * we append vnodes to a "workitem" queue. When running with a soft * updates implementation, most pending metadata dependencies should * not wait for more than a few seconds. Thus, mounted on block devices * are delayed only about a half the time that file data is delayed. * Similarly, directory updates are more critical, so are only delayed * about a third the time that file data is delayed. Thus, there are * SYNCER_MAXDELAY queues that are processed round-robin at a rate of * one each second (driven off the filesystem syner process). The * syncer_delayno variable indicates the next queue that is to be processed. * Items that need to be processed soon are placed in this queue: * * syncer_workitem_pending[syncer_delayno] * * A delay of fifteen seconds is done by placing the request fifteen * entries later in the queue: * * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] * */ /* * Add an item to the syncer work queue. */ void vn_syncer_add_to_worklist(vp, delay) struct vnode *vp; int delay; { int s, slot; s = splbio(); if (vp->v_flag & VONWORKLST) { LIST_REMOVE(vp, v_synclist); } if (delay > syncer_maxdelay - 2) delay = syncer_maxdelay - 2; slot = (syncer_delayno + delay) & syncer_mask; LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); vp->v_flag |= VONWORKLST; splx(s); } static void sched_sync __P((void)); static struct proc *updateproc; static struct kproc_desc up_kp = { "syncer", sched_sync, &updateproc }; SYSINIT_KT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) /* * System filesystem synchronizer daemon. */ void sched_sync(void) { struct synclist *slp; struct vnode *vp; long starttime; int s; struct proc *p = updateproc; for (;;) { starttime = time_second; /* * Push files whose dirty time has expired. */ s = splbio(); slp = &syncer_workitem_pending[syncer_delayno]; syncer_delayno += 1; if (syncer_delayno == syncer_maxdelay) syncer_delayno = 0; splx(s); while ((vp = LIST_FIRST(slp)) != NULL) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); (void) VOP_FSYNC(vp, p->p_ucred, MNT_LAZY, p); VOP_UNLOCK(vp, 0, p); if (LIST_FIRST(slp) == vp) { if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && vp->v_type != VBLK) panic("sched_sync: fsync failed"); /* * Move ourselves to the back of the sync list. */ LIST_REMOVE(vp, v_synclist); vn_syncer_add_to_worklist(vp, syncdelay); } } /* * Do soft update processing. */ if (bioops.io_sync) (*bioops.io_sync)(NULL); /* * The variable rushjob allows the kernel to speed up the * processing of the filesystem syncer process. A rushjob * value of N tells the filesystem syncer to process the next * N seconds worth of work on its queue ASAP. Currently rushjob * is used by the soft update code to speed up the filesystem * syncer process when the incore state is getting so far * ahead of the disk that the kernel memory pool is being * threatened with exhaustion. */ if (rushjob > 0) { rushjob -= 1; continue; } /* * If it has taken us less than a second to process the * current work, then wait. Otherwise start right over * again. We can still lose time if any single round * takes more than two seconds, but it does not really * matter as we are just trying to generally pace the * filesystem activity. */ if (time_second == starttime) tsleep(&lbolt, PPAUSE, "syncer", 0); } } /* * Associate a p-buffer with a vnode. */ void pbgetvp(vp, bp) register struct vnode *vp; register struct buf *bp; { KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); bp->b_vp = vp; if (vp->v_type == VBLK || vp->v_type == VCHR) bp->b_dev = vp->v_rdev; else bp->b_dev = NODEV; } /* * Disassociate a p-buffer from a vnode. */ void pbrelvp(bp) register struct buf *bp; { KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); bp->b_vp = (struct vnode *) 0; } /* * Reassign a buffer from one vnode to another. * Used to assign file specific control information * (indirect blocks) to the vnode to which they belong. */ void reassignbuf(bp, newvp) register struct buf *bp; register struct vnode *newvp; { struct buflists *listheadp; struct vnode *oldvp; int delay; int s; if (newvp == NULL) { printf("reassignbuf: NULL"); return; } s = splbio(); /* * Delete from old vnode list, if on one. */ if (bp->b_xflags & (B_VNDIRTY|B_VNCLEAN)) { oldvp = bp->b_vp; if (bp->b_xflags & B_VNDIRTY) listheadp = &oldvp->v_dirtyblkhd; else listheadp = &oldvp->v_cleanblkhd; TAILQ_REMOVE(listheadp, bp, b_vnbufs); bp->b_xflags &= ~(B_VNDIRTY|B_VNCLEAN); vdrop(oldvp); } /* * If dirty, put on list of dirty buffers; otherwise insert onto list * of clean buffers. */ if (bp->b_flags & B_DELWRI) { struct buf *tbp; listheadp = &newvp->v_dirtyblkhd; if ((newvp->v_flag & VONWORKLST) == 0) { switch (newvp->v_type) { case VDIR: delay = syncdelay / 3; break; case VBLK: if (newvp->v_specmountpoint != NULL) { delay = syncdelay / 2; break; } /* fall through */ default: delay = syncdelay; } vn_syncer_add_to_worklist(newvp, delay); } bp->b_xflags |= B_VNDIRTY; tbp = TAILQ_FIRST(listheadp); if (tbp == NULL || (bp->b_lblkno >= 0 && tbp->b_lblkno > bp->b_lblkno)) { TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs); } else { if (bp->b_lblkno >= 0) { struct buf *ttbp; while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) && (ttbp->b_lblkno < bp->b_lblkno)) { tbp = ttbp; } TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs); } else { TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs); } } } else { bp->b_xflags |= B_VNCLEAN; TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs); if ((newvp->v_flag & VONWORKLST) && TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { newvp->v_flag &= ~VONWORKLST; LIST_REMOVE(newvp, v_synclist); } } bp->b_vp = newvp; vhold(bp->b_vp); splx(s); } /* * Create a vnode for a block device. * Used for mounting the root file system. */ int bdevvp(dev, vpp) dev_t dev; struct vnode **vpp; { register struct vnode *vp; struct vnode *nvp; int error; /* XXX 255 is for mfs. */ if (dev == NODEV || (major(dev) != 255 && (major(dev) >= nblkdev || bdevsw[major(dev)] == NULL))) { *vpp = NULLVP; return (ENXIO); } error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp); if (error) { *vpp = NULLVP; return (error); } vp = nvp; vp->v_type = VBLK; if ((nvp = checkalias(vp, dev, (struct mount *)0)) != NULL) { vput(vp); vp = nvp; } *vpp = vp; return (0); } /* * Check to see if the new vnode represents a special device * for which we already have a vnode (either because of * bdevvp() or because of a different vnode representing * the same block device). If such an alias exists, deallocate * the existing contents and return the aliased vnode. The * caller is responsible for filling it with its new contents. */ struct vnode * checkalias(nvp, nvp_rdev, mp) register struct vnode *nvp; dev_t nvp_rdev; struct mount *mp; { struct proc *p = curproc; /* XXX */ struct vnode *vp; struct vnode **vpp; if (nvp->v_type != VBLK && nvp->v_type != VCHR) return (NULLVP); vpp = &speclisth[SPECHASH(nvp_rdev)]; loop: simple_lock(&spechash_slock); for (vp = *vpp; vp; vp = vp->v_specnext) { if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type) continue; /* * Alias, but not in use, so flush it out. * Only alias active device nodes. * Not sure why we don't re-use this like we do below. */ simple_lock(&vp->v_interlock); if (vp->v_usecount == 0) { simple_unlock(&spechash_slock); vgonel(vp, p); goto loop; } if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) { /* * It dissappeared, and we may have slept. * Restart from the beginning */ simple_unlock(&spechash_slock); goto loop; } break; } /* * It would be a lot clearer what is going on here if * this had been expressed as: * if ( vp && (vp->v_tag == VT_NULL)) * and the clauses had been swapped. */ if (vp == NULL || vp->v_tag != VT_NON) { /* * Put the new vnode into the hash chain. * and if there was an alias, connect them. */ MALLOC(nvp->v_specinfo, struct specinfo *, sizeof(struct specinfo), M_VNODE, M_WAITOK); nvp->v_rdev = nvp_rdev; nvp->v_hashchain = vpp; nvp->v_specnext = *vpp; nvp->v_specmountpoint = NULL; simple_unlock(&spechash_slock); *vpp = nvp; if (vp != NULLVP) { nvp->v_flag |= VALIASED; vp->v_flag |= VALIASED; vput(vp); } return (NULLVP); } /* * if ( vp && (vp->v_tag == VT_NULL)) * We have a vnode alias, but it is a trashed. * Make it look like it's newley allocated. (by getnewvnode()) * The caller should use this instead. */ simple_unlock(&spechash_slock); VOP_UNLOCK(vp, 0, p); simple_lock(&vp->v_interlock); vclean(vp, 0, p); vp->v_op = nvp->v_op; vp->v_tag = nvp->v_tag; nvp->v_type = VNON; insmntque(vp, mp); return (vp); } /* * Grab a particular vnode from the free list, increment its * reference count and lock it. The vnode lock bit is set the * vnode is being eliminated in vgone. The process is awakened * when the transition is completed, and an error returned to * indicate that the vnode is no longer usable (possibly having * been changed to a new file system type). */ int vget(vp, flags, p) register struct vnode *vp; int flags; struct proc *p; { int error; /* * If the vnode is in the process of being cleaned out for * another use, we wait for the cleaning to finish and then * return failure. Cleaning is determined by checking that * the VXLOCK flag is set. */ if ((flags & LK_INTERLOCK) == 0) { simple_lock(&vp->v_interlock); } if (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; simple_unlock(&vp->v_interlock); tsleep((caddr_t)vp, PINOD, "vget", 0); return (ENOENT); } vp->v_usecount++; if (VSHOULDBUSY(vp)) vbusy(vp); if (flags & LK_TYPE_MASK) { if ((error = vn_lock(vp, flags | LK_INTERLOCK, p)) != 0) { /* * must expand vrele here because we do not want * to call VOP_INACTIVE if the reference count * drops back to zero since it was never really * active. We must remove it from the free list * before sleeping so that multiple processes do * not try to recycle it. */ simple_lock(&vp->v_interlock); vp->v_usecount--; if (VSHOULDFREE(vp)) vfree(vp); simple_unlock(&vp->v_interlock); } return (error); } simple_unlock(&vp->v_interlock); return (0); } void vref(struct vnode *vp) { simple_lock(&vp->v_interlock); vp->v_usecount++; simple_unlock(&vp->v_interlock); } /* * Vnode put/release. * If count drops to zero, call inactive routine and return to freelist. */ void vrele(vp) struct vnode *vp; { struct proc *p = curproc; /* XXX */ KASSERT(vp != NULL, ("vrele: null vp")); simple_lock(&vp->v_interlock); if (vp->v_usecount > 1) { vp->v_usecount--; simple_unlock(&vp->v_interlock); return; } if (vp->v_usecount == 1) { vp->v_usecount--; if (VSHOULDFREE(vp)) vfree(vp); /* * If we are doing a vput, the node is already locked, and we must * call VOP_INACTIVE with the node locked. So, in the case of * vrele, we explicitly lock the vnode before calling VOP_INACTIVE. */ if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, p) == 0) { VOP_INACTIVE(vp, p); } } else { #ifdef DIAGNOSTIC vprint("vrele: negative ref count", vp); simple_unlock(&vp->v_interlock); #endif panic("vrele: negative ref cnt"); } } void vput(vp) struct vnode *vp; { struct proc *p = curproc; /* XXX */ KASSERT(vp != NULL, ("vput: null vp")); simple_lock(&vp->v_interlock); if (vp->v_usecount > 1) { vp->v_usecount--; VOP_UNLOCK(vp, LK_INTERLOCK, p); return; } if (vp->v_usecount == 1) { vp->v_usecount--; if (VSHOULDFREE(vp)) vfree(vp); /* * If we are doing a vput, the node is already locked, and we must * call VOP_INACTIVE with the node locked. So, in the case of * vrele, we explicitly lock the vnode before calling VOP_INACTIVE. */ simple_unlock(&vp->v_interlock); VOP_INACTIVE(vp, p); } else { #ifdef DIAGNOSTIC vprint("vput: negative ref count", vp); #endif panic("vput: negative ref cnt"); } } /* * Somebody doesn't want the vnode recycled. */ void vhold(vp) register struct vnode *vp; { int s; s = splbio(); vp->v_holdcnt++; if (VSHOULDBUSY(vp)) vbusy(vp); splx(s); } /* * One less who cares about this vnode. */ void vdrop(vp) register struct vnode *vp; { int s; s = splbio(); if (vp->v_holdcnt <= 0) panic("vdrop: holdcnt"); vp->v_holdcnt--; if (VSHOULDFREE(vp)) vfree(vp); splx(s); } /* * Remove any vnodes in the vnode table belonging to mount point mp. * * If MNT_NOFORCE is specified, there should not be any active ones, * return error if any are found (nb: this is a user error, not a * system error). If MNT_FORCE is specified, detach any active vnodes * that are found. */ #ifdef DIAGNOSTIC static int busyprt = 0; /* print out busy vnodes */ SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); #endif int vflush(mp, skipvp, flags) struct mount *mp; struct vnode *skipvp; int flags; { struct proc *p = curproc; /* XXX */ struct vnode *vp, *nvp; int busy = 0; simple_lock(&mntvnode_slock); loop: for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) { /* * Make sure this vnode wasn't reclaimed in getnewvnode(). * Start over if it has (it won't be on the list anymore). */ if (vp->v_mount != mp) goto loop; nvp = vp->v_mntvnodes.le_next; /* * Skip over a selected vnode. */ if (vp == skipvp) continue; simple_lock(&vp->v_interlock); /* * Skip over a vnodes marked VSYSTEM. */ if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) { simple_unlock(&vp->v_interlock); continue; } /* * If WRITECLOSE is set, only flush out regular file vnodes * open for writing. */ if ((flags & WRITECLOSE) && (vp->v_writecount == 0 || vp->v_type != VREG)) { simple_unlock(&vp->v_interlock); continue; } /* * With v_usecount == 0, all we need to do is clear out the * vnode data structures and we are done. */ if (vp->v_usecount == 0) { simple_unlock(&mntvnode_slock); vgonel(vp, p); simple_lock(&mntvnode_slock); continue; } /* * If FORCECLOSE is set, forcibly close the vnode. For block * or character devices, revert to an anonymous device. For * all other files, just kill them. */ if (flags & FORCECLOSE) { simple_unlock(&mntvnode_slock); if (vp->v_type != VBLK && vp->v_type != VCHR) { vgonel(vp, p); } else { vclean(vp, 0, p); vp->v_op = spec_vnodeop_p; insmntque(vp, (struct mount *) 0); } simple_lock(&mntvnode_slock); continue; } #ifdef DIAGNOSTIC if (busyprt) vprint("vflush: busy vnode", vp); #endif simple_unlock(&vp->v_interlock); busy++; } simple_unlock(&mntvnode_slock); if (busy) return (EBUSY); return (0); } /* * Disassociate the underlying file system from a vnode. */ static void vclean(vp, flags, p) struct vnode *vp; int flags; struct proc *p; { int active; vm_object_t obj; /* * Check to see if the vnode is in use. If so we have to reference it * before we clean it out so that its count cannot fall to zero and * generate a race against ourselves to recycle it. */ if ((active = vp->v_usecount)) vp->v_usecount++; /* * Prevent the vnode from being recycled or brought into use while we * clean it out. */ if (vp->v_flag & VXLOCK) panic("vclean: deadlock"); vp->v_flag |= VXLOCK; /* * Even if the count is zero, the VOP_INACTIVE routine may still * have the object locked while it cleans it out. The VOP_LOCK * ensures that the VOP_INACTIVE routine is done with its work. * For active vnodes, it ensures that no other activity can * occur while the underlying object is being cleaned out. */ VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, p); /* * Clean out any buffers associated with the vnode. */ vinvalbuf(vp, V_SAVE, NOCRED, p, 0, 0); if (obj = vp->v_object) { if (obj->ref_count == 0) { /* * This is a normal way of shutting down the object/vnode * association. */ vm_object_terminate(obj); } else { /* * Woe to the process that tries to page now :-). */ vm_pager_deallocate(obj); } } /* * If purging an active vnode, it must be closed and * deactivated before being reclaimed. Note that the * VOP_INACTIVE will unlock the vnode. */ if (active) { if (flags & DOCLOSE) VOP_CLOSE(vp, FNONBLOCK, NOCRED, p); VOP_INACTIVE(vp, p); } else { /* * Any other processes trying to obtain this lock must first * wait for VXLOCK to clear, then call the new lock operation. */ VOP_UNLOCK(vp, 0, p); } /* * Reclaim the vnode. */ if (VOP_RECLAIM(vp, p)) panic("vclean: cannot reclaim"); if (active) vrele(vp); cache_purge(vp); if (vp->v_vnlock) { #if 0 /* This is the only place we have LK_DRAINED in the entire kernel ??? */ #ifdef DIAGNOSTIC if ((vp->v_vnlock->lk_flags & LK_DRAINED) == 0) vprint("vclean: lock not drained", vp); #endif #endif FREE(vp->v_vnlock, M_VNODE); vp->v_vnlock = NULL; } if (VSHOULDFREE(vp)) vfree(vp); /* * Done with purge, notify sleepers of the grim news. */ vp->v_op = dead_vnodeop_p; vn_pollgone(vp); vp->v_tag = VT_NON; vp->v_flag &= ~VXLOCK; if (vp->v_flag & VXWANT) { vp->v_flag &= ~VXWANT; wakeup((caddr_t) vp); } } /* * Eliminate all activity associated with the requested vnode * and with all vnodes aliased to the requested vnode. */ int vop_revoke(ap) struct vop_revoke_args /* { struct vnode *a_vp; int a_flags; } */ *ap; { struct vnode *vp, *vq; struct proc *p = curproc; /* XXX */ KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); vp = ap->a_vp; simple_lock(&vp->v_interlock); if (vp->v_flag & VALIASED) { /* * If a vgone (or vclean) is already in progress, * wait until it is done and return. */ if (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; simple_unlock(&vp->v_interlock); tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0); return (0); } /* * Ensure that vp will not be vgone'd while we * are eliminating its aliases. */ vp->v_flag |= VXLOCK; simple_unlock(&vp->v_interlock); while (vp->v_flag & VALIASED) { simple_lock(&spechash_slock); for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type || vp == vq) continue; simple_unlock(&spechash_slock); vgone(vq); break; } if (vq == NULLVP) { simple_unlock(&spechash_slock); } } /* * Remove the lock so that vgone below will * really eliminate the vnode after which time * vgone will awaken any sleepers. */ simple_lock(&vp->v_interlock); vp->v_flag &= ~VXLOCK; if (vp->v_flag & VXWANT) { vp->v_flag &= ~VXWANT; wakeup(vp); } } vgonel(vp, p); return (0); } /* * Recycle an unused vnode to the front of the free list. * Release the passed interlock if the vnode will be recycled. */ int vrecycle(vp, inter_lkp, p) struct vnode *vp; struct simplelock *inter_lkp; struct proc *p; { simple_lock(&vp->v_interlock); if (vp->v_usecount == 0) { if (inter_lkp) { simple_unlock(inter_lkp); } vgonel(vp, p); return (1); } simple_unlock(&vp->v_interlock); return (0); } /* * Eliminate all activity associated with a vnode * in preparation for reuse. */ void vgone(vp) register struct vnode *vp; { struct proc *p = curproc; /* XXX */ simple_lock(&vp->v_interlock); vgonel(vp, p); } /* * vgone, with the vp interlock held. */ static void vgonel(vp, p) struct vnode *vp; struct proc *p; { int s; struct vnode *vq; struct vnode *vx; /* * If a vgone (or vclean) is already in progress, * wait until it is done and return. */ if (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; simple_unlock(&vp->v_interlock); tsleep((caddr_t)vp, PINOD, "vgone", 0); return; } /* * Clean out the filesystem specific data. */ vclean(vp, DOCLOSE, p); simple_lock(&vp->v_interlock); /* * Delete from old mount point vnode list, if on one. */ if (vp->v_mount != NULL) insmntque(vp, (struct mount *)0); /* * If special device, remove it from special device alias list * if it is on one. */ if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_specinfo != 0) { simple_lock(&spechash_slock); if (*vp->v_hashchain == vp) { *vp->v_hashchain = vp->v_specnext; } else { for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { if (vq->v_specnext != vp) continue; vq->v_specnext = vp->v_specnext; break; } if (vq == NULL) panic("missing bdev"); } if (vp->v_flag & VALIASED) { vx = NULL; for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type) continue; if (vx) break; vx = vq; } if (vx == NULL) panic("missing alias"); if (vq == NULL) vx->v_flag &= ~VALIASED; vp->v_flag &= ~VALIASED; } simple_unlock(&spechash_slock); FREE(vp->v_specinfo, M_VNODE); vp->v_specinfo = NULL; } /* * If it is on the freelist and not already at the head, * move it to the head of the list. The test of the back * pointer and the reference count of zero is because * it will be removed from the free list by getnewvnode, * but will not have its reference count incremented until * after calling vgone. If the reference count were * incremented first, vgone would (incorrectly) try to * close the previous instance of the underlying object. */ if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) { s = splbio(); simple_lock(&vnode_free_list_slock); if (vp->v_flag & VFREE) { TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); } else if (vp->v_flag & VTBFREE) { TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist); vp->v_flag &= ~VTBFREE; freevnodes++; } else freevnodes++; vp->v_flag |= VFREE; TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); simple_unlock(&vnode_free_list_slock); splx(s); } vp->v_type = VBAD; simple_unlock(&vp->v_interlock); } /* * Lookup a vnode by device number. */ int vfinddev(dev, type, vpp) dev_t dev; enum vtype type; struct vnode **vpp; { register struct vnode *vp; int rc = 0; simple_lock(&spechash_slock); for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) { if (dev != vp->v_rdev || type != vp->v_type) continue; *vpp = vp; rc = 1; break; } simple_unlock(&spechash_slock); return (rc); } /* * Calculate the total number of references to a special device. */ int vcount(vp) register struct vnode *vp; { struct vnode *vq, *vnext; int count; loop: if ((vp->v_flag & VALIASED) == 0) return (vp->v_usecount); simple_lock(&spechash_slock); for (count = 0, vq = *vp->v_hashchain; vq; vq = vnext) { vnext = vq->v_specnext; if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type) continue; /* * Alias, but not in use, so flush it out. */ if (vq->v_usecount == 0 && vq != vp) { simple_unlock(&spechash_slock); vgone(vq); goto loop; } count += vq->v_usecount; } simple_unlock(&spechash_slock); return (count); } /* * Print out a description of a vnode. */ static char *typename[] = {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; void vprint(label, vp) char *label; register struct vnode *vp; { char buf[96]; if (label != NULL) printf("%s: %p: ", label, (void *)vp); else printf("%p: ", (void *)vp); printf("type %s, usecount %d, writecount %d, refcount %d,", typename[vp->v_type], vp->v_usecount, vp->v_writecount, vp->v_holdcnt); buf[0] = '\0'; if (vp->v_flag & VROOT) strcat(buf, "|VROOT"); if (vp->v_flag & VTEXT) strcat(buf, "|VTEXT"); if (vp->v_flag & VSYSTEM) strcat(buf, "|VSYSTEM"); if (vp->v_flag & VXLOCK) strcat(buf, "|VXLOCK"); if (vp->v_flag & VXWANT) strcat(buf, "|VXWANT"); if (vp->v_flag & VBWAIT) strcat(buf, "|VBWAIT"); if (vp->v_flag & VALIASED) strcat(buf, "|VALIASED"); if (vp->v_flag & VDOOMED) strcat(buf, "|VDOOMED"); if (vp->v_flag & VFREE) strcat(buf, "|VFREE"); if (vp->v_flag & VOBJBUF) strcat(buf, "|VOBJBUF"); if (buf[0] != '\0') printf(" flags (%s)", &buf[1]); if (vp->v_data == NULL) { printf("\n"); } else { printf("\n\t"); VOP_PRINT(vp); } } #ifdef DDB #include /* * List all of the locked vnodes in the system. * Called when debugging the kernel. */ DB_SHOW_COMMAND(lockedvnodes, lockedvnodes) { struct proc *p = curproc; /* XXX */ struct mount *mp, *nmp; struct vnode *vp; printf("Locked vnodes\n"); simple_lock(&mountlist_slock); for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) { if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) { nmp = mp->mnt_list.cqe_next; continue; } for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = vp->v_mntvnodes.le_next) { if (VOP_ISLOCKED(vp)) vprint((char *)0, vp); } simple_lock(&mountlist_slock); nmp = mp->mnt_list.cqe_next; vfs_unbusy(mp, p); } simple_unlock(&mountlist_slock); } #endif /* * Top level filesystem related information gathering. */ static int sysctl_ovfs_conf __P(SYSCTL_HANDLER_ARGS); static int vfs_sysctl SYSCTL_HANDLER_ARGS { int *name = (int *)arg1 - 1; /* XXX */ u_int namelen = arg2 + 1; /* XXX */ struct vfsconf *vfsp; #if 1 || defined(COMPAT_PRELITE2) /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ if (namelen == 1) return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); #endif #ifdef notyet /* all sysctl names at this level are at least name and field */ if (namelen < 2) return (ENOTDIR); /* overloaded */ if (name[0] != VFS_GENERIC) { for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) if (vfsp->vfc_typenum == name[0]) break; if (vfsp == NULL) return (EOPNOTSUPP); return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1, oldp, oldlenp, newp, newlen, p)); } #endif switch (name[1]) { case VFS_MAXTYPENUM: if (namelen != 2) return (ENOTDIR); return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); case VFS_CONF: if (namelen != 3) return (ENOTDIR); /* overloaded */ for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) if (vfsp->vfc_typenum == name[2]) break; if (vfsp == NULL) return (EOPNOTSUPP); return (SYSCTL_OUT(req, vfsp, sizeof *vfsp)); } return (EOPNOTSUPP); } SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl, "Generic filesystem"); #if 1 || defined(COMPAT_PRELITE2) static int sysctl_ovfs_conf SYSCTL_HANDLER_ARGS { int error; struct vfsconf *vfsp; struct ovfsconf ovfs; for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ strcpy(ovfs.vfc_name, vfsp->vfc_name); ovfs.vfc_index = vfsp->vfc_typenum; ovfs.vfc_refcount = vfsp->vfc_refcount; ovfs.vfc_flags = vfsp->vfc_flags; error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); if (error) return error; } return 0; } #endif /* 1 || COMPAT_PRELITE2 */ #if 0 #define KINFO_VNODESLOP 10 /* * Dump vnode list (via sysctl). * Copyout address of vnode followed by vnode. */ /* ARGSUSED */ static int sysctl_vnode SYSCTL_HANDLER_ARGS { struct proc *p = curproc; /* XXX */ struct mount *mp, *nmp; struct vnode *nvp, *vp; int error; #define VPTRSZ sizeof (struct vnode *) #define VNODESZ sizeof (struct vnode) req->lock = 0; if (!req->oldptr) /* Make an estimate */ return (SYSCTL_OUT(req, 0, (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ))); simple_lock(&mountlist_slock); for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) { if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) { nmp = mp->mnt_list.cqe_next; continue; } again: simple_lock(&mntvnode_slock); for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) { /* * Check that the vp is still associated with * this filesystem. RACE: could have been * recycled onto the same filesystem. */ if (vp->v_mount != mp) { simple_unlock(&mntvnode_slock); goto again; } nvp = vp->v_mntvnodes.le_next; simple_unlock(&mntvnode_slock); if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) || (error = SYSCTL_OUT(req, vp, VNODESZ))) return (error); simple_lock(&mntvnode_slock); } simple_unlock(&mntvnode_slock); simple_lock(&mountlist_slock); nmp = mp->mnt_list.cqe_next; vfs_unbusy(mp, p); } simple_unlock(&mountlist_slock); return (0); } #endif /* * XXX * Exporting the vnode list on large systems causes them to crash. * Exporting the vnode list on medium systems causes sysctl to coredump. */ #if 0 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0, sysctl_vnode, "S,vnode", ""); #endif /* * Check to see if a filesystem is mounted on a block device. */ int vfs_mountedon(vp) struct vnode *vp; { struct vnode *vq; int error = 0; if (vp->v_specmountpoint != NULL) return (EBUSY); if (vp->v_flag & VALIASED) { simple_lock(&spechash_slock); for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type) continue; if (vq->v_specmountpoint != NULL) { error = EBUSY; break; } } simple_unlock(&spechash_slock); } return (error); } /* * Unmount all filesystems. The list is traversed in reverse order * of mounting to avoid dependencies. */ void vfs_unmountall() { struct mount *mp, *nmp; struct proc *p; int error; if (curproc != NULL) p = curproc; else p = initproc; /* XXX XXX should this be proc0? */ /* * Since this only runs when rebooting, it is not interlocked. */ for (mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) { nmp = mp->mnt_list.cqe_prev; error = dounmount(mp, MNT_FORCE, p); if (error) { printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); if (error == EBUSY) printf("BUSY)\n"); else printf("%d)\n", error); } } } /* * Build hash lists of net addresses and hang them off the mount point. * Called by ufs_mount() to set up the lists of export addresses. */ static int vfs_hang_addrlist(mp, nep, argp) struct mount *mp; struct netexport *nep; struct export_args *argp; { register struct netcred *np; register struct radix_node_head *rnh; register int i; struct radix_node *rn; struct sockaddr *saddr, *smask = 0; struct domain *dom; int error; if (argp->ex_addrlen == 0) { if (mp->mnt_flag & MNT_DEFEXPORTED) return (EPERM); np = &nep->ne_defexported; np->netc_exflags = argp->ex_flags; np->netc_anon = argp->ex_anon; np->netc_anon.cr_ref = 1; mp->mnt_flag |= MNT_DEFEXPORTED; return (0); } i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK); bzero((caddr_t) np, i); saddr = (struct sockaddr *) (np + 1); if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen))) goto out; if (saddr->sa_len > argp->ex_addrlen) saddr->sa_len = argp->ex_addrlen; if (argp->ex_masklen) { smask = (struct sockaddr *) ((caddr_t) saddr + argp->ex_addrlen); error = copyin(argp->ex_mask, (caddr_t) smask, argp->ex_masklen); if (error) goto out; if (smask->sa_len > argp->ex_masklen) smask->sa_len = argp->ex_masklen; } i = saddr->sa_family; if ((rnh = nep->ne_rtable[i]) == 0) { /* * Seems silly to initialize every AF when most are not used, * do so on demand here */ for (dom = domains; dom; dom = dom->dom_next) if (dom->dom_family == i && dom->dom_rtattach) { dom->dom_rtattach((void **) &nep->ne_rtable[i], dom->dom_rtoffset); break; } if ((rnh = nep->ne_rtable[i]) == 0) { error = ENOBUFS; goto out; } } rn = (*rnh->rnh_addaddr) ((caddr_t) saddr, (caddr_t) smask, rnh, np->netc_rnodes); if (rn == 0 || np != (struct netcred *) rn) { /* already exists */ error = EPERM; goto out; } np->netc_exflags = argp->ex_flags; np->netc_anon = argp->ex_anon; np->netc_anon.cr_ref = 1; return (0); out: free(np, M_NETADDR); return (error); } /* ARGSUSED */ static int vfs_free_netcred(rn, w) struct radix_node *rn; void *w; { register struct radix_node_head *rnh = (struct radix_node_head *) w; (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh); free((caddr_t) rn, M_NETADDR); return (0); } /* * Free the net address hash lists that are hanging off the mount points. */ static void vfs_free_addrlist(nep) struct netexport *nep; { register int i; register struct radix_node_head *rnh; for (i = 0; i <= AF_MAX; i++) if ((rnh = nep->ne_rtable[i])) { (*rnh->rnh_walktree) (rnh, vfs_free_netcred, (caddr_t) rnh); free((caddr_t) rnh, M_RTABLE); nep->ne_rtable[i] = 0; } } int vfs_export(mp, nep, argp) struct mount *mp; struct netexport *nep; struct export_args *argp; { int error; if (argp->ex_flags & MNT_DELEXPORT) { if (mp->mnt_flag & MNT_EXPUBLIC) { vfs_setpublicfs(NULL, NULL, NULL); mp->mnt_flag &= ~MNT_EXPUBLIC; } vfs_free_addrlist(nep); mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); } if (argp->ex_flags & MNT_EXPORTED) { if (argp->ex_flags & MNT_EXPUBLIC) { if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) return (error); mp->mnt_flag |= MNT_EXPUBLIC; } if ((error = vfs_hang_addrlist(mp, nep, argp))) return (error); mp->mnt_flag |= MNT_EXPORTED; } return (0); } /* * Set the publicly exported filesystem (WebNFS). Currently, only * one public filesystem is possible in the spec (RFC 2054 and 2055) */ int vfs_setpublicfs(mp, nep, argp) struct mount *mp; struct netexport *nep; struct export_args *argp; { int error; struct vnode *rvp; char *cp; /* * mp == NULL -> invalidate the current info, the FS is * no longer exported. May be called from either vfs_export * or unmount, so check if it hasn't already been done. */ if (mp == NULL) { if (nfs_pub.np_valid) { nfs_pub.np_valid = 0; if (nfs_pub.np_index != NULL) { FREE(nfs_pub.np_index, M_TEMP); nfs_pub.np_index = NULL; } } return (0); } /* * Only one allowed at a time. */ if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) return (EBUSY); /* * Get real filehandle for root of exported FS. */ bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; if ((error = VFS_ROOT(mp, &rvp))) return (error); if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) return (error); vput(rvp); /* * If an indexfile was specified, pull it in. */ if (argp->ex_indexfile != NULL) { MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP, M_WAITOK); error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, MAXNAMLEN, (size_t *)0); if (!error) { /* * Check for illegal filenames. */ for (cp = nfs_pub.np_index; *cp; cp++) { if (*cp == '/') { error = EINVAL; break; } } } if (error) { FREE(nfs_pub.np_index, M_TEMP); return (error); } } nfs_pub.np_mount = mp; nfs_pub.np_valid = 1; return (0); } struct netcred * vfs_export_lookup(mp, nep, nam) register struct mount *mp; struct netexport *nep; struct sockaddr *nam; { register struct netcred *np; register struct radix_node_head *rnh; struct sockaddr *saddr; np = NULL; if (mp->mnt_flag & MNT_EXPORTED) { /* * Lookup in the export list first. */ if (nam != NULL) { saddr = nam; rnh = nep->ne_rtable[saddr->sa_family]; if (rnh != NULL) { np = (struct netcred *) (*rnh->rnh_matchaddr)((caddr_t)saddr, rnh); if (np && np->netc_rnodes->rn_flags & RNF_ROOT) np = NULL; } } /* * If no address match, use the default if it exists. */ if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED) np = &nep->ne_defexported; } return (np); } /* * perform msync on all vnodes under a mount point * the mount point must be locked. */ void vfs_msync(struct mount *mp, int flags) { struct vnode *vp, *nvp; struct vm_object *obj; int anyio, tries; tries = 5; loop: anyio = 0; for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) { nvp = vp->v_mntvnodes.le_next; if (vp->v_mount != mp) { goto loop; } if (vp->v_flag & VXLOCK) /* XXX: what if MNT_WAIT? */ continue; if (flags != MNT_WAIT) { obj = vp->v_object; if (obj == NULL || (obj->flags & OBJ_MIGHTBEDIRTY) == 0) continue; if (VOP_ISLOCKED(vp)) continue; } simple_lock(&vp->v_interlock); if (vp->v_object && (vp->v_object->flags & OBJ_MIGHTBEDIRTY)) { if (!vget(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curproc)) { if (vp->v_object) { vm_object_page_clean(vp->v_object, 0, 0, flags == MNT_WAIT ? OBJPC_SYNC : 0); anyio = 1; } vput(vp); } } else { simple_unlock(&vp->v_interlock); } } if (anyio && (--tries > 0)) goto loop; } /* * Create the VM object needed for VMIO and mmap support. This * is done for all VREG files in the system. Some filesystems might * afford the additional metadata buffering capability of the * VMIO code by making the device node be VMIO mode also. * * vp must be locked when vfs_object_create is called. */ int vfs_object_create(vp, p, cred) struct vnode *vp; struct proc *p; struct ucred *cred; { struct vattr vat; vm_object_t object; int error = 0; if ((vp->v_type != VREG) && (vp->v_type != VBLK)) return 0; retry: if ((object = vp->v_object) == NULL) { if (vp->v_type == VREG) { if ((error = VOP_GETATTR(vp, &vat, cred, p)) != 0) goto retn; object = vnode_pager_alloc(vp, vat.va_size, 0, 0); } else if (major(vp->v_rdev) < nblkdev && bdevsw[major(vp->v_rdev)] != NULL) { /* * This simply allocates the biggest object possible * for a VBLK vnode. This should be fixed, but doesn't * cause any problems (yet). */ object = vnode_pager_alloc(vp, IDX_TO_OFF(INT_MAX), 0, 0); } object->ref_count--; vp->v_usecount--; } else { if (object->flags & OBJ_DEAD) { VOP_UNLOCK(vp, 0, p); tsleep(object, PVM, "vodead", 0); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); goto retry; } } if (vp->v_object) vp->v_flag |= VOBJBUF; retn: return error; } static void vfree(vp) struct vnode *vp; { int s; s = splbio(); simple_lock(&vnode_free_list_slock); if (vp->v_flag & VTBFREE) { TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist); vp->v_flag &= ~VTBFREE; } if (vp->v_flag & VAGE) { TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); } else { TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); } freevnodes++; simple_unlock(&vnode_free_list_slock); vp->v_flag &= ~VAGE; vp->v_flag |= VFREE; splx(s); } void vbusy(vp) struct vnode *vp; { int s; s = splbio(); simple_lock(&vnode_free_list_slock); if (vp->v_flag & VTBFREE) { TAILQ_REMOVE(&vnode_tobefree_list, vp, v_freelist); vp->v_flag &= ~VTBFREE; } else { TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); freevnodes--; } simple_unlock(&vnode_free_list_slock); vp->v_flag &= ~(VFREE|VAGE); splx(s); } /* * Record a process's interest in events which might happen to * a vnode. Because poll uses the historic select-style interface * internally, this routine serves as both the ``check for any * pending events'' and the ``record my interest in future events'' * functions. (These are done together, while the lock is held, * to avoid race conditions.) */ int vn_pollrecord(vp, p, events) struct vnode *vp; struct proc *p; short events; { simple_lock(&vp->v_pollinfo.vpi_lock); if (vp->v_pollinfo.vpi_revents & events) { /* * This leaves events we are not interested * in available for the other process which * which presumably had requested them * (otherwise they would never have been * recorded). */ events &= vp->v_pollinfo.vpi_revents; vp->v_pollinfo.vpi_revents &= ~events; simple_unlock(&vp->v_pollinfo.vpi_lock); return events; } vp->v_pollinfo.vpi_events |= events; selrecord(p, &vp->v_pollinfo.vpi_selinfo); simple_unlock(&vp->v_pollinfo.vpi_lock); return 0; } /* * Note the occurrence of an event. If the VN_POLLEVENT macro is used, * it is possible for us to miss an event due to race conditions, but * that condition is expected to be rare, so for the moment it is the * preferred interface. */ void vn_pollevent(vp, events) struct vnode *vp; short events; { simple_lock(&vp->v_pollinfo.vpi_lock); if (vp->v_pollinfo.vpi_events & events) { /* * We clear vpi_events so that we don't * call selwakeup() twice if two events are * posted before the polling process(es) is * awakened. This also ensures that we take at * most one selwakeup() if the polling process * is no longer interested. However, it does * mean that only one event can be noticed at * a time. (Perhaps we should only clear those * event bits which we note?) XXX */ vp->v_pollinfo.vpi_events = 0; /* &= ~events ??? */ vp->v_pollinfo.vpi_revents |= events; selwakeup(&vp->v_pollinfo.vpi_selinfo); } simple_unlock(&vp->v_pollinfo.vpi_lock); } /* * Wake up anyone polling on vp because it is being revoked. * This depends on dead_poll() returning POLLHUP for correct * behavior. */ void vn_pollgone(vp) struct vnode *vp; { simple_lock(&vp->v_pollinfo.vpi_lock); if (vp->v_pollinfo.vpi_events) { vp->v_pollinfo.vpi_events = 0; selwakeup(&vp->v_pollinfo.vpi_selinfo); } simple_unlock(&vp->v_pollinfo.vpi_lock); } /* * Routine to create and manage a filesystem syncer vnode. */ #define sync_close ((int (*) __P((struct vop_close_args *)))nullop) static int sync_fsync __P((struct vop_fsync_args *)); static int sync_inactive __P((struct vop_inactive_args *)); static int sync_reclaim __P((struct vop_reclaim_args *)); #define sync_lock ((int (*) __P((struct vop_lock_args *)))vop_nolock) #define sync_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock) static int sync_print __P((struct vop_print_args *)); #define sync_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked) static vop_t **sync_vnodeop_p; static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { { &vop_default_desc, (vop_t *) vop_eopnotsupp }, { &vop_close_desc, (vop_t *) sync_close }, /* close */ { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ { &vop_lock_desc, (vop_t *) sync_lock }, /* lock */ { &vop_unlock_desc, (vop_t *) sync_unlock }, /* unlock */ { &vop_print_desc, (vop_t *) sync_print }, /* print */ { &vop_islocked_desc, (vop_t *) sync_islocked }, /* islocked */ { NULL, NULL } }; static struct vnodeopv_desc sync_vnodeop_opv_desc = { &sync_vnodeop_p, sync_vnodeop_entries }; VNODEOP_SET(sync_vnodeop_opv_desc); /* * Create a new filesystem syncer vnode for the specified mount point. */ int vfs_allocate_syncvnode(mp) struct mount *mp; { struct vnode *vp; static long start, incr, next; int error; /* Allocate a new vnode */ if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) { mp->mnt_syncer = NULL; return (error); } vp->v_type = VNON; /* * Place the vnode onto the syncer worklist. We attempt to * scatter them about on the list so that they will go off * at evenly distributed times even if all the filesystems * are mounted at once. */ next += incr; if (next == 0 || next > syncer_maxdelay) { start /= 2; incr /= 2; if (start == 0) { start = syncer_maxdelay / 2; incr = syncer_maxdelay; } next = start; } vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); mp->mnt_syncer = vp; return (0); } /* * Do a lazy sync of the filesystem. */ static int sync_fsync(ap) struct vop_fsync_args /* { struct vnode *a_vp; struct ucred *a_cred; int a_waitfor; struct proc *a_p; } */ *ap; { struct vnode *syncvp = ap->a_vp; struct mount *mp = syncvp->v_mount; struct proc *p = ap->a_p; int asyncflag; /* * We only need to do something if this is a lazy evaluation. */ if (ap->a_waitfor != MNT_LAZY) return (0); /* * Move ourselves to the back of the sync list. */ vn_syncer_add_to_worklist(syncvp, syncdelay); /* * Walk the list of vnodes pushing all that are dirty and * not already on the sync list. */ simple_lock(&mountlist_slock); if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_slock, p) != 0) { simple_unlock(&mountlist_slock); return (0); } asyncflag = mp->mnt_flag & MNT_ASYNC; mp->mnt_flag &= ~MNT_ASYNC; vfs_msync(mp, MNT_NOWAIT); VFS_SYNC(mp, MNT_LAZY, ap->a_cred, p); if (asyncflag) mp->mnt_flag |= MNT_ASYNC; vfs_unbusy(mp, p); return (0); } /* * The syncer vnode is no referenced. */ static int sync_inactive(ap) struct vop_inactive_args /* { struct vnode *a_vp; struct proc *a_p; } */ *ap; { vgone(ap->a_vp); return (0); } /* * The syncer vnode is no longer needed and is being decommissioned. */ static int sync_reclaim(ap) struct vop_reclaim_args /* { struct vnode *a_vp; } */ *ap; { struct vnode *vp = ap->a_vp; vp->v_mount->mnt_syncer = NULL; if (vp->v_flag & VONWORKLST) { LIST_REMOVE(vp, v_synclist); vp->v_flag &= ~VONWORKLST; } return (0); } /* * Print out a syncer vnode. */ static int sync_print(ap) struct vop_print_args /* { struct vnode *a_vp; } */ *ap; { struct vnode *vp = ap->a_vp; printf("syncer vnode"); if (vp->v_vnlock != NULL) lockmgr_printinfo(vp->v_vnlock); printf("\n"); return (0); }