/* * 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 */ /* * External virtual filesystem routines */ #include __FBSDID("$FreeBSD$"); #include "opt_ddb.h" #include "opt_mac.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 #include static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); static void addalias(struct vnode *vp, dev_t nvp_rdev); static void insmntque(struct vnode *vp, struct mount *mp); static void vclean(struct vnode *vp, int flags, struct thread *td); static void vlruvp(struct vnode *vp); static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, int slpflag, int slptimeo, int *errorp); static int vtryrecycle(struct vnode *vp); static void vx_lock(struct vnode *vp); static void vx_unlock(struct vnode *vp); static void vgonechrl(struct vnode *vp, struct thread *td); /* * Number of vnodes in existence. Increased whenever getnewvnode() * allocates a new vnode, never decreased. */ static unsigned long numvnodes; SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); /* * Conversion tables for conversion from vnode types to inode formats * and back. */ 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, }; /* * List of vnodes that are ready for recycling. */ static TAILQ_HEAD(freelst, vnode) vnode_free_list; /* * Minimum number of free vnodes. If there are fewer than this free vnodes, * getnewvnode() will return a newly allocated vnode. */ static u_long wantfreevnodes = 25; SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); /* Number of vnodes in the free list. */ static u_long freevnodes; SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); /* * Various variables used for debugging the new implementation of * reassignbuf(). * XXX these are probably of (very) limited utility now. */ static int reassignbufcalls; SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); static int nameileafonly; SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); /* * Cache for the mount type id assigned to NFS. This is used for * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. */ int nfs_mount_type = -1; /* To keep more than one thread at a time from running vfs_getnewfsid */ static struct mtx mntid_mtx; /* * Lock for any access to the following: * vnode_free_list * numvnodes * freevnodes */ static struct mtx vnode_free_list_mtx; /* * For any iteration/modification of dev->si_hlist (linked through * v_specnext) */ static struct mtx spechash_mtx; /* Publicly exported FS */ struct nfs_public nfs_pub; /* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ static uma_zone_t vnode_zone; static uma_zone_t vnodepoll_zone; /* Set to 1 to print out reclaim of active vnodes */ int prtactive; /* * 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 syncer 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] * */ static int syncer_delayno; static long syncer_mask; LIST_HEAD(synclist, vnode); static struct synclist *syncer_workitem_pending; /* * The sync_mtx protects: * vp->v_synclist * syncer_delayno * syncer_workitem_pending * rushjob */ static struct mtx sync_mtx; #define SYNCER_MAXDELAY 32 static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ static int syncdelay = 30; /* max time to delay syncing data */ static int filedelay = 30; /* time to delay syncing files */ SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); static int dirdelay = 29; /* time to delay syncing directories */ SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); static int metadelay = 28; /* time to delay syncing metadata */ SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); static int rushjob; /* number of slots to run ASAP */ static int stat_rush_requests; /* number of times I/O speeded up */ SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); /* * Number of vnodes we want to exist at any one time. This is mostly used * to size hash tables in vnode-related code. It is normally not used in * getnewvnode(), as wantfreevnodes is normally nonzero.) * * XXX desiredvnodes is historical cruft and should not exist. */ int desiredvnodes; SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, &desiredvnodes, 0, "Maximum number of vnodes"); static int minvnodes; SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, &minvnodes, 0, "Minimum number of vnodes"); static int vnlru_nowhere; SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); /* Hook for calling soft updates */ int (*softdep_process_worklist_hook)(struct mount *); /* * This only exists to supress warnings from unlocked specfs accesses. It is * no longer ok to have an unlocked VFS. */ #define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) /* Print lock violations */ int vfs_badlock_print = 1; /* Panic on violation */ int vfs_badlock_panic = 1; /* Check for interlock across VOPs */ int vfs_badlock_mutex = 1; static void vfs_badlock(const char *msg, const char *str, struct vnode *vp) { if (vfs_badlock_print) printf("%s: %p %s\n", str, vp, msg); if (vfs_badlock_panic) Debugger("Lock violation."); } void assert_vi_unlocked(struct vnode *vp, const char *str) { if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) vfs_badlock("interlock is locked but should not be", str, vp); } void assert_vi_locked(struct vnode *vp, const char *str) { if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) vfs_badlock("interlock is not locked but should be", str, vp); } void assert_vop_locked(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && !VOP_ISLOCKED(vp, NULL)) vfs_badlock("is not locked but should be", str, vp); } void assert_vop_unlocked(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) vfs_badlock("is locked but should not be", str, vp); } void assert_vop_elocked(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) vfs_badlock("is not exclusive locked but should be", str, vp); } void assert_vop_elocked_other(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) vfs_badlock("is not exclusive locked by another thread", str, vp); } void assert_vop_slocked(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, curthread) != LK_SHARED) vfs_badlock("is not locked shared but should be", str, vp); } void vop_rename_pre(void *ap) { struct vop_rename_args *a = ap; if (a->a_tvp) ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); /* Check the source (from) */ if (a->a_tdvp != a->a_fdvp) ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); if (a->a_tvp != a->a_fvp) ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); /* Check the target */ if (a->a_tvp) ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); } void vop_strategy_pre(void *ap) { struct vop_strategy_args *a = ap; struct buf *bp; bp = a->a_bp; /* * Cluster ops lock their component buffers but not the IO container. */ if ((bp->b_flags & B_CLUSTER) != 0) return; if (BUF_REFCNT(bp) < 1) { if (vfs_badlock_print) printf("VOP_STRATEGY: bp is not locked but should be.\n"); if (vfs_badlock_panic) Debugger("Lock violation."); } } void vop_lookup_pre(void *ap) { struct vop_lookup_args *a = ap; struct vnode *dvp; dvp = a->a_dvp; ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); } void vop_lookup_post(void *ap, int rc) { struct vop_lookup_args *a = ap; struct componentname *cnp; struct vnode *dvp; struct vnode *vp; int flags; dvp = a->a_dvp; cnp = a->a_cnp; vp = *(a->a_vpp); flags = cnp->cn_flags; ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); /* * If this is the last path component for this lookup and LOCPARENT * is set, OR if there is an error the directory has to be locked. */ if ((flags & LOCKPARENT) && (flags & ISLASTCN)) ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); else if (rc != 0) ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); else if (dvp != vp) ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); if (flags & PDIRUNLOCK) ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); } void vop_unlock_pre(void *ap) { struct vop_unlock_args *a = ap; if (a->a_flags & LK_INTERLOCK) ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); } void vop_unlock_post(void *ap, int rc) { struct vop_unlock_args *a = ap; if (a->a_flags & LK_INTERLOCK) ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); } void vop_lock_pre(void *ap) { struct vop_lock_args *a = ap; if ((a->a_flags & LK_INTERLOCK) == 0) ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); else ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); } void vop_lock_post(void *ap, int rc) { struct vop_lock_args *a; a = ap; ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); if (rc == 0) ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); } void v_addpollinfo(struct vnode *vp) { vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); } /* * Initialize the vnode management data structures. */ static void vntblinit(void *dummy __unused) { /* * Desiredvnodes is a function of the physical memory size and * the kernel's heap size. Specifically, desiredvnodes scales * in proportion to the physical memory size until two fifths * of the kernel's heap size is consumed by vnodes and vm * objects. */ desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); minvnodes = desiredvnodes / 4; mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); TAILQ_INIT(&vnode_free_list); mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); /* * Initialize the filesystem syncer. */ syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, &syncer_mask); syncer_maxdelay = syncer_mask + 1; mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); } SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) /* * 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, td) struct mount *mp; int flags; struct mtx *interlkp; struct thread *td; { int lkflags; if (mp->mnt_kern_flag & MNTK_UNMOUNT) { if (flags & LK_NOWAIT) return (ENOENT); mp->mnt_kern_flag |= MNTK_MWAIT; /* * 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. */ msleep(mp, interlkp, PVFS, "vfs_busy", 0); return (ENOENT); } lkflags = LK_SHARED | LK_NOPAUSE; if (interlkp) lkflags |= LK_INTERLOCK; if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) panic("vfs_busy: unexpected lock failure"); return (0); } /* * Free a busy filesystem. */ void vfs_unbusy(mp, td) struct mount *mp; struct thread *td; { lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); } /* * Lookup a mount point by filesystem identifier. */ struct mount * vfs_getvfs(fsid) fsid_t *fsid; { register struct mount *mp; mtx_lock(&mountlist_mtx); TAILQ_FOREACH(mp, &mountlist, mnt_list) { if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { mtx_unlock(&mountlist_mtx); return (mp); } } mtx_unlock(&mountlist_mtx); return ((struct mount *) 0); } /* * Get a new unique fsid. Try to make its val[0] unique, since this value * will be used to create fake device numbers for stat(). Also try (but * not so hard) make its val[0] unique mod 2^16, since some emulators only * support 16-bit device numbers. We end up with unique val[0]'s for the * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. * * Keep in mind that several mounts may be running in parallel. Starting * the search one past where the previous search terminated is both a * micro-optimization and a defense against returning the same fsid to * different mounts. */ void vfs_getnewfsid(mp) struct mount *mp; { static u_int16_t mntid_base; fsid_t tfsid; int mtype; mtx_lock(&mntid_mtx); mtype = mp->mnt_vfc->vfc_typenum; tfsid.val[1] = mtype; mtype = (mtype & 0xFF) << 24; for (;;) { tfsid.val[0] = makeudev(255, mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); mntid_base++; if (vfs_getvfs(&tfsid) == NULL) break; } mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; mtx_unlock(&mntid_mtx); } /* * Knob to control the precision of file timestamps: * * 0 = seconds only; nanoseconds zeroed. * 1 = seconds and nanoseconds, accurate within 1/HZ. * 2 = seconds and nanoseconds, truncated to microseconds. * >=3 = seconds and nanoseconds, maximum precision. */ enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; static int timestamp_precision = TSP_SEC; SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, ×tamp_precision, 0, ""); /* * Get a current timestamp. */ void vfs_timestamp(tsp) struct timespec *tsp; { struct timeval tv; switch (timestamp_precision) { case TSP_SEC: tsp->tv_sec = time_second; tsp->tv_nsec = 0; break; case TSP_HZ: getnanotime(tsp); break; case TSP_USEC: microtime(&tv); TIMEVAL_TO_TIMESPEC(&tv, tsp); break; case TSP_NSEC: default: nanotime(tsp); break; } } /* * 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_birthtime.tv_sec = VNOVAL; vap->va_birthtime.tv_nsec = VNOVAL; vap->va_flags = VNOVAL; vap->va_gen = VNOVAL; vap->va_vaflags = 0; } /* * This routine is called when we have too many vnodes. It attempts * to free vnodes and will potentially free vnodes that still * have VM backing store (VM backing store is typically the cause * of a vnode blowout so we want to do this). Therefore, this operation * is not considered cheap. * * A number of conditions may prevent a vnode from being reclaimed. * the buffer cache may have references on the vnode, a directory * vnode may still have references due to the namei cache representing * underlying files, or the vnode may be in active use. It is not * desireable to reuse such vnodes. These conditions may cause the * number of vnodes to reach some minimum value regardless of what * you set kern.maxvnodes to. Do not set kern.maxvnodes too low. */ static int vlrureclaim(struct mount *mp) { struct vnode *vp; int done; int trigger; int usevnodes; int count; /* * Calculate the trigger point, don't allow user * screwups to blow us up. This prevents us from * recycling vnodes with lots of resident pages. We * aren't trying to free memory, we are trying to * free vnodes. */ usevnodes = desiredvnodes; if (usevnodes <= 0) usevnodes = 1; trigger = cnt.v_page_count * 2 / usevnodes; done = 0; MNT_ILOCK(mp); count = mp->mnt_nvnodelistsize / 10 + 1; while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); if (vp->v_type != VNON && vp->v_type != VBAD && VI_TRYLOCK(vp)) { if (VMIGHTFREE(vp) && /* critical path opt */ (vp->v_object == NULL || vp->v_object->resident_page_count < trigger)) { MNT_IUNLOCK(mp); vgonel(vp, curthread); done++; MNT_ILOCK(mp); } else VI_UNLOCK(vp); } --count; } MNT_IUNLOCK(mp); return done; } /* * Attempt to recycle vnodes in a context that is always safe to block. * Calling vlrurecycle() from the bowels of filesystem code has some * interesting deadlock problems. */ static struct proc *vnlruproc; static int vnlruproc_sig; static void vnlru_proc(void) { struct mount *mp, *nmp; int done; struct proc *p = vnlruproc; struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ mtx_lock(&Giant); EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, SHUTDOWN_PRI_FIRST); for (;;) { kthread_suspend_check(p); mtx_lock(&vnode_free_list_mtx); if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { mtx_unlock(&vnode_free_list_mtx); vnlruproc_sig = 0; wakeup(&vnlruproc_sig); tsleep(vnlruproc, PVFS, "vlruwt", hz); continue; } mtx_unlock(&vnode_free_list_mtx); done = 0; mtx_lock(&mountlist_mtx); for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { nmp = TAILQ_NEXT(mp, mnt_list); continue; } done += vlrureclaim(mp); mtx_lock(&mountlist_mtx); nmp = TAILQ_NEXT(mp, mnt_list); vfs_unbusy(mp, td); } mtx_unlock(&mountlist_mtx); if (done == 0) { #if 0 /* These messages are temporary debugging aids */ if (vnlru_nowhere < 5) printf("vnlru process getting nowhere..\n"); else if (vnlru_nowhere == 5) printf("vnlru process messages stopped.\n"); #endif vnlru_nowhere++; tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); } } } static struct kproc_desc vnlru_kp = { "vnlru", vnlru_proc, &vnlruproc }; SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) /* * Routines having to do with the management of the vnode table. */ /* * Check to see if a free vnode can be recycled. If it can, * recycle it and return it with the vnode interlock held. */ static int vtryrecycle(struct vnode *vp) { struct thread *td = curthread; vm_object_t object; struct mount *vnmp; int error; /* Don't recycle if we can't get the interlock */ if (!VI_TRYLOCK(vp)) return (EWOULDBLOCK); /* * This vnode may found and locked via some other list, if so we * can't recycle it yet. */ if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_NOWAIT, td) != 0) return (EWOULDBLOCK); /* * Don't recycle if its filesystem is being suspended. */ if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { error = EBUSY; goto done; } /* * Don't recycle if we still have cached pages. */ if (VOP_GETVOBJECT(vp, &object) == 0) { VM_OBJECT_LOCK(object); if (object->resident_page_count || object->ref_count) { VM_OBJECT_UNLOCK(object); error = EBUSY; goto done; } VM_OBJECT_UNLOCK(object); } if (LIST_FIRST(&vp->v_cache_src)) { /* * note: nameileafonly sysctl is temporary, * for debugging only, and will eventually be * removed. */ if (nameileafonly > 0) { /* * Do not reuse namei-cached directory * vnodes that have cached * subdirectories. */ if (cache_leaf_test(vp) < 0) { error = EISDIR; goto done; } } else if (nameileafonly < 0 || vmiodirenable == 0) { /* * Do not reuse namei-cached directory * vnodes if nameileafonly is -1 or * if VMIO backing for directories is * turned off (otherwise we reuse them * too quickly). */ error = EBUSY; goto done; } } /* * If we got this far, we need to acquire the interlock and see if * anyone picked up this vnode from another list. If not, we will * mark it with XLOCK via vgonel() so that anyone who does find it * will skip over it. */ VI_LOCK(vp); if (VSHOULDBUSY(vp) && (vp->v_iflag & VI_XLOCK) == 0) { VI_UNLOCK(vp); error = EBUSY; goto done; } mtx_lock(&vnode_free_list_mtx); TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); vp->v_iflag &= ~VI_FREE; mtx_unlock(&vnode_free_list_mtx); vp->v_iflag |= VI_DOOMED; if (vp->v_type != VBAD) { VOP_UNLOCK(vp, 0, td); vgonel(vp, td); VI_LOCK(vp); } else VOP_UNLOCK(vp, 0, td); vn_finished_write(vnmp); return (0); done: VOP_UNLOCK(vp, 0, td); return (error); } /* * Return the next vnode from the free list. */ int getnewvnode(tag, mp, vops, vpp) const char *tag; struct mount *mp; vop_t **vops; struct vnode **vpp; { struct vnode *vp = NULL; struct vpollinfo *pollinfo = NULL; mtx_lock(&vnode_free_list_mtx); /* * Try to reuse vnodes if we hit the max. This situation only * occurs in certain large-memory (2G+) situations. We cannot * attempt to directly reclaim vnodes due to nasty recursion * problems. */ while (numvnodes - freevnodes > desiredvnodes) { if (vnlruproc_sig == 0) { vnlruproc_sig = 1; /* avoid unnecessary wakeups */ wakeup(vnlruproc); } mtx_unlock(&vnode_free_list_mtx); tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); mtx_lock(&vnode_free_list_mtx); } /* * Attempt to reuse a vnode already on the free list, allocating * a new vnode if we can't find one or if we have not reached a * good minimum for good LRU performance. */ if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { int error; int count; for (count = 0; count < freevnodes; count++) { vp = TAILQ_FIRST(&vnode_free_list); KASSERT(vp->v_usecount == 0 && (vp->v_iflag & VI_DOINGINACT) == 0, ("getnewvnode: free vnode isn't")); TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); mtx_unlock(&vnode_free_list_mtx); error = vtryrecycle(vp); mtx_lock(&vnode_free_list_mtx); if (error == 0) break; vp = NULL; } } if (vp) { freevnodes--; mtx_unlock(&vnode_free_list_mtx); #ifdef INVARIANTS { if (vp->v_data) panic("cleaned vnode isn't"); if (vp->v_numoutput) panic("Clean vnode has pending I/O's"); if (vp->v_writecount != 0) panic("Non-zero write count"); } #endif if ((pollinfo = vp->v_pollinfo) != NULL) { /* * To avoid lock order reversals, the call to * uma_zfree() must be delayed until the vnode * interlock is released. */ vp->v_pollinfo = NULL; } #ifdef MAC mac_destroy_vnode(vp); #endif vp->v_iflag = 0; vp->v_vflag = 0; vp->v_lastw = 0; vp->v_lasta = 0; vp->v_cstart = 0; vp->v_clen = 0; vp->v_socket = 0; lockdestroy(vp->v_vnlock); lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); } else { numvnodes++; mtx_unlock(&vnode_free_list_mtx); vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); VI_LOCK(vp); vp->v_dd = vp; vp->v_vnlock = &vp->v_lock; lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); cache_purge(vp); /* Sets up v_id. */ LIST_INIT(&vp->v_cache_src); TAILQ_INIT(&vp->v_cache_dst); } TAILQ_INIT(&vp->v_cleanblkhd); TAILQ_INIT(&vp->v_dirtyblkhd); vp->v_type = VNON; vp->v_tag = tag; vp->v_op = vops; *vpp = vp; vp->v_usecount = 1; vp->v_data = 0; vp->v_cachedid = -1; VI_UNLOCK(vp); if (pollinfo != NULL) { mtx_destroy(&pollinfo->vpi_lock); uma_zfree(vnodepoll_zone, pollinfo); } #ifdef MAC mac_init_vnode(vp); if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) mac_associate_vnode_singlelabel(mp, vp); #endif insmntque(vp, mp); return (0); } /* * Move a vnode from one mount queue to another. */ static void insmntque(vp, mp) register struct vnode *vp; register struct mount *mp; { /* * Delete from old mount point vnode list, if on one. */ if (vp->v_mount != NULL) { MNT_ILOCK(vp->v_mount); KASSERT(vp->v_mount->mnt_nvnodelistsize > 0, ("bad mount point vnode list size")); TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); vp->v_mount->mnt_nvnodelistsize--; MNT_IUNLOCK(vp->v_mount); } /* * Insert into list of vnodes for the new mount point, if available. */ if ((vp->v_mount = mp) != NULL) { MNT_ILOCK(vp->v_mount); TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); mp->mnt_nvnodelistsize++; MNT_IUNLOCK(vp->v_mount); } } /* * 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)) { VI_LOCK(vp); vp->v_numoutput--; if (vp->v_numoutput < 0) panic("vwakeup: neg numoutput"); if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { vp->v_iflag &= ~VI_BWAIT; wakeup(&vp->v_numoutput); } VI_UNLOCK(vp); } } /* * Flush out and invalidate all buffers associated with a vnode. * Called with the underlying object locked. */ int vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) struct vnode *vp; int flags; struct ucred *cred; struct thread *td; int slpflag, slptimeo; { struct buf *blist; int error; vm_object_t object; GIANT_REQUIRED; ASSERT_VOP_LOCKED(vp, "vinvalbuf"); VI_LOCK(vp); if (flags & V_SAVE) { while (vp->v_numoutput) { vp->v_iflag |= VI_BWAIT; error = msleep(&vp->v_numoutput, VI_MTX(vp), slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); if (error) { VI_UNLOCK(vp); return (error); } } if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { VI_UNLOCK(vp); if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) return (error); /* * XXX We could save a lock/unlock if this was only * enabled under INVARIANTS */ VI_LOCK(vp); if (vp->v_numoutput > 0 || !TAILQ_EMPTY(&vp->v_dirtyblkhd)) panic("vinvalbuf: dirty bufs"); } } /* * If you alter this loop please notice that interlock is dropped and * reacquired in flushbuflist. Special care is needed to ensure that * no race conditions occur from this. */ for (error = 0;;) { if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { if (error) break; continue; } if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { if (error) break; continue; } break; } if (error) { VI_UNLOCK(vp); return (error); } /* * Wait for I/O to complete. XXX needs cleaning up. The vnode can * have write I/O in-progress but if there is a VM object then the * VM object can also have read-I/O in-progress. */ do { while (vp->v_numoutput > 0) { vp->v_iflag |= VI_BWAIT; msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); } VI_UNLOCK(vp); if (VOP_GETVOBJECT(vp, &object) == 0) { VM_OBJECT_LOCK(object); vm_object_pip_wait(object, "vnvlbx"); VM_OBJECT_UNLOCK(object); } VI_LOCK(vp); } while (vp->v_numoutput > 0); VI_UNLOCK(vp); /* * Destroy the copy in the VM cache, too. */ if (VOP_GETVOBJECT(vp, &object) == 0) { VM_OBJECT_LOCK(object); vm_object_page_remove(object, 0, 0, (flags & V_SAVE) ? TRUE : FALSE); VM_OBJECT_UNLOCK(object); } #ifdef INVARIANTS VI_LOCK(vp); if ((flags & (V_ALT | V_NORMAL)) == 0 && (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd))) panic("vinvalbuf: flush failed"); VI_UNLOCK(vp); #endif return (0); } /* * Flush out buffers on the specified list. * */ static int flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) struct buf *blist; int flags; struct vnode *vp; int slpflag, slptimeo; int *errorp; { struct buf *bp, *nbp; int found, error; ASSERT_VI_LOCKED(vp, "flushbuflist"); for (found = 0, bp = blist; bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { continue; } found += 1; error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), "flushbuf", slpflag, slptimeo); if (error) { if (error != ENOLCK) *errorp = error; goto done; } /* * 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 BUF_WRITE 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_ASYNC; BUF_WRITE(bp); } } else { bremfree(bp); (void) BUF_WRITE(bp); } goto done; } bremfree(bp); bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); VI_LOCK(vp); } return (found); done: VI_LOCK(vp); return (found); } /* * 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, td, length, blksize) register struct vnode *vp; struct ucred *cred; struct thread *td; off_t length; int blksize; { register struct buf *bp; struct buf *nbp; int anyfreed; int trunclbn; /* * Round up to the *next* lbn. */ trunclbn = (length + blksize - 1) / blksize; ASSERT_VOP_LOCKED(vp, "vtruncbuf"); restart: VI_LOCK(vp); 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 (BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp)) == ENOLCK) goto restart; bremfree(bp); bp->b_flags |= (B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); anyfreed = 1; if (nbp && (((nbp->b_xflags & BX_VNCLEAN) == 0) || (nbp->b_vp != vp) || (nbp->b_flags & B_DELWRI))) { goto restart; } VI_LOCK(vp); } } for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (bp->b_lblkno >= trunclbn) { if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp)) == ENOLCK) goto restart; bremfree(bp); bp->b_flags |= (B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); anyfreed = 1; if (nbp && (((nbp->b_xflags & BX_VNDIRTY) == 0) || (nbp->b_vp != vp) || (nbp->b_flags & B_DELWRI) == 0)) { goto restart; } VI_LOCK(vp); } } } if (length > 0) { restartsync: for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { nbp = TAILQ_NEXT(bp, b_vnbufs); if (bp->b_lblkno > 0) continue; /* * Since we hold the vnode lock this should only * fail if we're racing with the buf daemon. */ if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp)) == ENOLCK) { goto restart; } KASSERT((bp->b_flags & B_DELWRI), ("buf(%p) on dirty queue without DELWRI.", bp)); bremfree(bp); bawrite(bp); VI_LOCK(vp); goto restartsync; } } while (vp->v_numoutput > 0) { vp->v_iflag |= VI_BWAIT; msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); } VI_UNLOCK(vp); vnode_pager_setsize(vp, length); return (0); } /* * buf_splay() - splay tree core for the clean/dirty list of buffers in * a vnode. * * NOTE: We have to deal with the special case of a background bitmap * buffer, a situation where two buffers will have the same logical * block offset. We want (1) only the foreground buffer to be accessed * in a lookup and (2) must differentiate between the foreground and * background buffer in the splay tree algorithm because the splay * tree cannot normally handle multiple entities with the same 'index'. * We accomplish this by adding differentiating flags to the splay tree's * numerical domain. */ static struct buf * buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) { struct buf dummy; struct buf *lefttreemax, *righttreemin, *y; if (root == NULL) return (NULL); lefttreemax = righttreemin = &dummy; for (;;) { if (lblkno < root->b_lblkno || (lblkno == root->b_lblkno && (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { if ((y = root->b_left) == NULL) break; if (lblkno < y->b_lblkno) { /* Rotate right. */ root->b_left = y->b_right; y->b_right = root; root = y; if ((y = root->b_left) == NULL) break; } /* Link into the new root's right tree. */ righttreemin->b_left = root; righttreemin = root; } else if (lblkno > root->b_lblkno || (lblkno == root->b_lblkno && (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { if ((y = root->b_right) == NULL) break; if (lblkno > y->b_lblkno) { /* Rotate left. */ root->b_right = y->b_left; y->b_left = root; root = y; if ((y = root->b_right) == NULL) break; } /* Link into the new root's left tree. */ lefttreemax->b_right = root; lefttreemax = root; } else { break; } root = y; } /* Assemble the new root. */ lefttreemax->b_right = root->b_left; righttreemin->b_left = root->b_right; root->b_left = dummy.b_right; root->b_right = dummy.b_left; return (root); } static void buf_vlist_remove(struct buf *bp) { struct vnode *vp = bp->b_vp; struct buf *root; ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); if (bp->b_xflags & BX_VNDIRTY) { if (bp != vp->v_dirtyblkroot) { root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); KASSERT(root == bp, ("splay lookup failed during dirty remove")); } if (bp->b_left == NULL) { root = bp->b_right; } else { root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); root->b_right = bp->b_right; } vp->v_dirtyblkroot = root; TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); vp->v_dirtybufcnt--; } else { /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ if (bp != vp->v_cleanblkroot) { root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); KASSERT(root == bp, ("splay lookup failed during clean remove")); } if (bp->b_left == NULL) { root = bp->b_right; } else { root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); root->b_right = bp->b_right; } vp->v_cleanblkroot = root; TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); vp->v_cleanbufcnt--; } bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); } /* * Add the buffer to the sorted clean or dirty block list using a * splay tree algorithm. * * NOTE: xflags is passed as a constant, optimizing this inline function! */ static void buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) { struct buf *root; ASSERT_VI_LOCKED(vp, "buf_vlist_add"); bp->b_xflags |= xflags; if (xflags & BX_VNDIRTY) { root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); if (root == NULL) { bp->b_left = NULL; bp->b_right = NULL; TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); } else if (bp->b_lblkno < root->b_lblkno || (bp->b_lblkno == root->b_lblkno && (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { bp->b_left = root->b_left; bp->b_right = root; root->b_left = NULL; TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); } else { bp->b_right = root->b_right; bp->b_left = root; root->b_right = NULL; TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, root, bp, b_vnbufs); } vp->v_dirtybufcnt++; vp->v_dirtyblkroot = bp; } else { /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); if (root == NULL) { bp->b_left = NULL; bp->b_right = NULL; TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); } else if (bp->b_lblkno < root->b_lblkno || (bp->b_lblkno == root->b_lblkno && (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { bp->b_left = root->b_left; bp->b_right = root; root->b_left = NULL; TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); } else { bp->b_right = root->b_right; bp->b_left = root; root->b_right = NULL; TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, root, bp, b_vnbufs); } vp->v_cleanbufcnt++; vp->v_cleanblkroot = bp; } } /* * Lookup a buffer using the splay tree. Note that we specifically avoid * shadow buffers used in background bitmap writes. * * This code isn't quite efficient as it could be because we are maintaining * two sorted lists and do not know which list the block resides in. * * During a "make buildworld" the desired buffer is found at one of * the roots more than 60% of the time. Thus, checking both roots * before performing either splay eliminates unnecessary splays on the * first tree splayed. */ struct buf * gbincore(struct vnode *vp, daddr_t lblkno) { struct buf *bp; GIANT_REQUIRED; ASSERT_VI_LOCKED(vp, "gbincore"); if ((bp = vp->v_cleanblkroot) != NULL && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); if ((bp = vp->v_dirtyblkroot) != NULL && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); if ((bp = vp->v_cleanblkroot) != NULL) { vp->v_cleanblkroot = bp = buf_splay(lblkno, 0, bp); if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); } if ((bp = vp->v_dirtyblkroot) != NULL) { vp->v_dirtyblkroot = bp = buf_splay(lblkno, 0, bp); if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); } return (NULL); } /* * Associate a buffer with a vnode. */ void bgetvp(vp, bp) register struct vnode *vp; register struct buf *bp; { KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, ("bgetvp: bp already attached! %p", bp)); ASSERT_VI_LOCKED(vp, "bgetvp"); vholdl(vp); bp->b_vp = vp; bp->b_dev = vn_todev(vp); /* * Insert onto list for new vnode. */ buf_vlist_add(bp, vp, BX_VNCLEAN); } /* * Disassociate a buffer from a vnode. */ void brelvp(bp) register struct buf *bp; { struct vnode *vp; KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); /* * Delete from old vnode list, if on one. */ vp = bp->b_vp; VI_LOCK(vp); if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) buf_vlist_remove(bp); if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { vp->v_iflag &= ~VI_ONWORKLST; mtx_lock(&sync_mtx); LIST_REMOVE(vp, v_synclist); mtx_unlock(&sync_mtx); } vdropl(vp); bp->b_vp = (struct vnode *) 0; if (bp->b_object) bp->b_object = NULL; VI_UNLOCK(vp); } /* * Add an item to the syncer work queue. */ static void vn_syncer_add_to_worklist(struct vnode *vp, int delay) { int slot; ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); mtx_lock(&sync_mtx); if (vp->v_iflag & VI_ONWORKLST) LIST_REMOVE(vp, v_synclist); else vp->v_iflag |= VI_ONWORKLST; 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); mtx_unlock(&sync_mtx); } struct proc *updateproc; static void sched_sync(void); static struct kproc_desc up_kp = { "syncer", sched_sync, &updateproc }; SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) /* * System filesystem synchronizer daemon. */ static void sched_sync(void) { struct synclist *next; struct synclist *slp; struct vnode *vp; struct mount *mp; long starttime; struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ mtx_lock(&Giant); EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, SHUTDOWN_PRI_LAST); for (;;) { kthread_suspend_check(td->td_proc); starttime = time_second; /* * Push files whose dirty time has expired. Be careful * of interrupt race on slp queue. */ mtx_lock(&sync_mtx); slp = &syncer_workitem_pending[syncer_delayno]; syncer_delayno += 1; if (syncer_delayno == syncer_maxdelay) syncer_delayno = 0; next = &syncer_workitem_pending[syncer_delayno]; while ((vp = LIST_FIRST(slp)) != NULL) { if (VOP_ISLOCKED(vp, NULL) != 0 || vn_start_write(vp, &mp, V_NOWAIT) != 0) { LIST_REMOVE(vp, v_synclist); LIST_INSERT_HEAD(next, vp, v_synclist); continue; } if (VI_TRYLOCK(vp) == 0) { LIST_REMOVE(vp, v_synclist); LIST_INSERT_HEAD(next, vp, v_synclist); vn_finished_write(mp); continue; } /* * We use vhold in case the vnode does not * successfully sync. vhold prevents the vnode from * going away when we unlock the sync_mtx so that * we can acquire the vnode interlock. */ vholdl(vp); mtx_unlock(&sync_mtx); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, td); (void) VOP_FSYNC(vp, td->td_ucred, MNT_LAZY, td); VOP_UNLOCK(vp, 0, td); vn_finished_write(mp); VI_LOCK(vp); if ((vp->v_iflag & VI_ONWORKLST) != 0) { /* * Put us back on the worklist. The worklist * routine will remove us from our current * position and then add us back in at a later * position. */ vn_syncer_add_to_worklist(vp, syncdelay); } vdropl(vp); VI_UNLOCK(vp); mtx_lock(&sync_mtx); } mtx_unlock(&sync_mtx); /* * Do soft update processing. */ if (softdep_process_worklist_hook != NULL) (*softdep_process_worklist_hook)(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. */ mtx_lock(&sync_mtx); if (rushjob > 0) { rushjob -= 1; mtx_unlock(&sync_mtx); continue; } mtx_unlock(&sync_mtx); /* * 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); } } /* * Request the syncer daemon to speed up its work. * We never push it to speed up more than half of its * normal turn time, otherwise it could take over the cpu. * XXXKSE only one update? */ int speedup_syncer() { struct thread *td; int ret = 0; td = FIRST_THREAD_IN_PROC(updateproc); mtx_lock_spin(&sched_lock); if (td->td_wchan == &lbolt) { unsleep(td); TD_CLR_SLEEPING(td); setrunnable(td); } mtx_unlock_spin(&sched_lock); mtx_lock(&sync_mtx); if (rushjob < syncdelay / 2) { rushjob += 1; stat_rush_requests += 1; ret = 1; } mtx_unlock(&sync_mtx); return (ret); } /* * Associate a p-buffer with a vnode. * * Also sets B_PAGING flag to indicate that vnode is not fully associated * with the buffer. i.e. the bp has not been linked into the vnode or * ref-counted. */ void pbgetvp(vp, bp) register struct vnode *vp; register struct buf *bp; { KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); bp->b_vp = vp; bp->b_object = vp->v_object; bp->b_flags |= B_PAGING; bp->b_dev = vn_todev(vp); } /* * Disassociate a p-buffer from a vnode. */ void pbrelvp(bp) register struct buf *bp; { KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); /* XXX REMOVE ME */ VI_LOCK(bp->b_vp); if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { panic( "relpbuf(): b_vp was probably reassignbuf()d %p %x", bp, (int)bp->b_flags ); } VI_UNLOCK(bp->b_vp); bp->b_vp = (struct vnode *) 0; bp->b_object = NULL; bp->b_flags &= ~B_PAGING; } /* * 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 vnode *vp; int delay; if (newvp == NULL) { printf("reassignbuf: NULL"); return; } vp = bp->b_vp; ++reassignbufcalls; /* * B_PAGING flagged buffers cannot be reassigned because their vp * is not fully linked in. */ if (bp->b_flags & B_PAGING) panic("cannot reassign paging buffer"); /* * Delete from old vnode list, if on one. */ VI_LOCK(vp); if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { buf_vlist_remove(bp); if (vp != newvp) { vdropl(bp->b_vp); bp->b_vp = NULL; /* for clarification */ } } if (vp != newvp) { VI_UNLOCK(vp); VI_LOCK(newvp); } /* * If dirty, put on list of dirty buffers; otherwise insert onto list * of clean buffers. */ if (bp->b_flags & B_DELWRI) { if ((newvp->v_iflag & VI_ONWORKLST) == 0) { switch (newvp->v_type) { case VDIR: delay = dirdelay; break; case VCHR: if (newvp->v_rdev->si_mountpoint != NULL) { delay = metadelay; break; } /* FALLTHROUGH */ default: delay = filedelay; } vn_syncer_add_to_worklist(newvp, delay); } buf_vlist_add(bp, newvp, BX_VNDIRTY); } else { buf_vlist_add(bp, newvp, BX_VNCLEAN); if ((newvp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { mtx_lock(&sync_mtx); LIST_REMOVE(newvp, v_synclist); mtx_unlock(&sync_mtx); newvp->v_iflag &= ~VI_ONWORKLST; } } if (bp->b_vp != newvp) { bp->b_vp = newvp; vholdl(bp->b_vp); } VI_UNLOCK(newvp); } /* * Create a vnode for a device. * Used for mounting the root filesystem. */ int bdevvp(dev, vpp) dev_t dev; struct vnode **vpp; { register struct vnode *vp; struct vnode *nvp; int error; if (dev == NODEV) { *vpp = NULLVP; return (ENXIO); } if (vfinddev(dev, VCHR, vpp)) return (0); error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); if (error) { *vpp = NULLVP; return (error); } vp = nvp; vp->v_type = VCHR; addalias(vp, dev); *vpp = vp; return (0); } static void v_incr_usecount(struct vnode *vp, int delta) { vp->v_usecount += delta; if (vp->v_type == VCHR && vp->v_rdev != NULL) { mtx_lock(&spechash_mtx); vp->v_rdev->si_usecount += delta; mtx_unlock(&spechash_mtx); } } /* * Add vnode to the alias list hung off the dev_t. * * The reason for this gunk is that multiple vnodes can reference * the same physical device, so checking vp->v_usecount to see * how many users there are is inadequate; the v_usecount for * the vnodes need to be accumulated. vcount() does that. */ struct vnode * addaliasu(nvp, nvp_rdev) struct vnode *nvp; udev_t nvp_rdev; { struct vnode *ovp; vop_t **ops; dev_t dev; if (nvp->v_type == VBLK) return (nvp); if (nvp->v_type != VCHR) panic("addaliasu on non-special vnode"); dev = udev2dev(nvp_rdev, 0); /* * Check to see if we have a bdevvp vnode with no associated * filesystem. If so, we want to associate the filesystem of * the new newly instigated vnode with the bdevvp vnode and * discard the newly created vnode rather than leaving the * bdevvp vnode lying around with no associated filesystem. */ if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { addalias(nvp, dev); return (nvp); } /* * Discard unneeded vnode, but save its node specific data. * Note that if there is a lock, it is carried over in the * node specific data to the replacement vnode. */ vref(ovp); ovp->v_data = nvp->v_data; ovp->v_tag = nvp->v_tag; nvp->v_data = NULL; lockdestroy(ovp->v_vnlock); lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); ops = ovp->v_op; ovp->v_op = nvp->v_op; if (VOP_ISLOCKED(nvp, curthread)) { VOP_UNLOCK(nvp, 0, curthread); vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); } nvp->v_op = ops; insmntque(ovp, nvp->v_mount); vrele(nvp); vgone(nvp); return (ovp); } /* This is a local helper function that do the same as addaliasu, but for a * dev_t instead of an udev_t. */ static void addalias(nvp, dev) struct vnode *nvp; dev_t dev; { KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); nvp->v_rdev = dev; VI_LOCK(nvp); mtx_lock(&spechash_mtx); SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); dev->si_usecount += nvp->v_usecount; mtx_unlock(&spechash_mtx); VI_UNLOCK(nvp); } /* * Grab a particular vnode from the free list, increment its * reference count and lock it. The vnode lock bit is set if 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 filesystem type). */ int vget(vp, flags, td) register struct vnode *vp; int flags; struct thread *td; { 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 VI_XLOCK flag is set. */ if ((flags & LK_INTERLOCK) == 0) VI_LOCK(vp); if (vp->v_iflag & VI_XLOCK && vp->v_vxthread != curthread) { if ((flags & LK_NOWAIT) == 0) { vp->v_iflag |= VI_XWANT; msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); return (ENOENT); } VI_UNLOCK(vp); return (EBUSY); } v_incr_usecount(vp, 1); if (VSHOULDBUSY(vp)) vbusy(vp); if (flags & LK_TYPE_MASK) { if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 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. */ VI_LOCK(vp); v_incr_usecount(vp, -1); if (VSHOULDFREE(vp)) vfree(vp); else vlruvp(vp); VI_UNLOCK(vp); } return (error); } VI_UNLOCK(vp); return (0); } /* * Increase the reference count of a vnode. */ void vref(struct vnode *vp) { VI_LOCK(vp); v_incr_usecount(vp, 1); VI_UNLOCK(vp); } /* * Return reference count of a vnode. * * The results of this call are only guaranteed when some mechanism other * than the VI lock is used to stop other processes from gaining references * to the vnode. This may be the case if the caller holds the only reference. * This is also useful when stale data is acceptable as race conditions may * be accounted for by some other means. */ int vrefcnt(struct vnode *vp) { int usecnt; VI_LOCK(vp); usecnt = vp->v_usecount; VI_UNLOCK(vp); return (usecnt); } /* * Vnode put/release. * If count drops to zero, call inactive routine and return to freelist. */ void vrele(vp) struct vnode *vp; { struct thread *td = curthread; /* XXX */ KASSERT(vp != NULL, ("vrele: null vp")); VI_LOCK(vp); /* Skip this v_writecount check if we're going to panic below. */ KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, ("vrele: missed vn_close")); if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && vp->v_usecount == 1)) { v_incr_usecount(vp, -1); VI_UNLOCK(vp); return; } if (vp->v_usecount == 1) { v_incr_usecount(vp, -1); /* * We must call VOP_INACTIVE with the node locked. Mark * as VI_DOINGINACT to avoid recursion. */ if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { VI_LOCK(vp); vp->v_iflag |= VI_DOINGINACT; VI_UNLOCK(vp); VOP_INACTIVE(vp, td); VI_LOCK(vp); KASSERT(vp->v_iflag & VI_DOINGINACT, ("vrele: lost VI_DOINGINACT")); vp->v_iflag &= ~VI_DOINGINACT; } else VI_LOCK(vp); if (VSHOULDFREE(vp)) vfree(vp); else vlruvp(vp); VI_UNLOCK(vp); } else { #ifdef DIAGNOSTIC vprint("vrele: negative ref count", vp); #endif VI_UNLOCK(vp); panic("vrele: negative ref cnt"); } } /* * Release an already locked vnode. This give the same effects as * unlock+vrele(), but takes less time and avoids releasing and * re-aquiring the lock (as vrele() aquires the lock internally.) */ void vput(vp) struct vnode *vp; { struct thread *td = curthread; /* XXX */ GIANT_REQUIRED; KASSERT(vp != NULL, ("vput: null vp")); VI_LOCK(vp); /* Skip this v_writecount check if we're going to panic below. */ KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, ("vput: missed vn_close")); if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && vp->v_usecount == 1)) { v_incr_usecount(vp, -1); VOP_UNLOCK(vp, LK_INTERLOCK, td); return; } if (vp->v_usecount == 1) { v_incr_usecount(vp, -1); /* * We must call VOP_INACTIVE with the node locked, so * we just need to release the vnode mutex. Mark as * as VI_DOINGINACT to avoid recursion. */ vp->v_iflag |= VI_DOINGINACT; VI_UNLOCK(vp); VOP_INACTIVE(vp, td); VI_LOCK(vp); KASSERT(vp->v_iflag & VI_DOINGINACT, ("vput: lost VI_DOINGINACT")); vp->v_iflag &= ~VI_DOINGINACT; if (VSHOULDFREE(vp)) vfree(vp); else vlruvp(vp); VI_UNLOCK(vp); } else { #ifdef DIAGNOSTIC vprint("vput: negative ref count", vp); #endif panic("vput: negative ref cnt"); } } /* * Somebody doesn't want the vnode recycled. */ void vhold(struct vnode *vp) { VI_LOCK(vp); vholdl(vp); VI_UNLOCK(vp); } void vholdl(vp) register struct vnode *vp; { vp->v_holdcnt++; if (VSHOULDBUSY(vp)) vbusy(vp); } /* * Note that there is one less who cares about this vnode. vdrop() is the * opposite of vhold(). */ void vdrop(struct vnode *vp) { VI_LOCK(vp); vdropl(vp); VI_UNLOCK(vp); } void vdropl(vp) register struct vnode *vp; { if (vp->v_holdcnt <= 0) panic("vdrop: holdcnt"); vp->v_holdcnt--; if (VSHOULDFREE(vp)) vfree(vp); else vlruvp(vp); } /* * Remove any vnodes in the vnode table belonging to mount point mp. * * If FORCECLOSE is not 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 FORCECLOSE is specified, detach any active vnodes * that are found. * * If WRITECLOSE is set, only flush out regular file vnodes open for * writing. * * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped. * * `rootrefs' specifies the base reference count for the root vnode * of this filesystem. The root vnode is considered busy if its * v_usecount exceeds this value. On a successful return, vflush() * will call vrele() on the root vnode exactly rootrefs times. * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must * be zero. */ #ifdef DIAGNOSTIC static int busyprt = 0; /* print out busy vnodes */ SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); #endif int vflush(mp, rootrefs, flags) struct mount *mp; int rootrefs; int flags; { struct thread *td = curthread; /* XXX */ struct vnode *vp, *nvp, *rootvp = NULL; struct vattr vattr; int busy = 0, error; if (rootrefs > 0) { KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, ("vflush: bad args")); /* * Get the filesystem root vnode. We can vput() it * immediately, since with rootrefs > 0, it won't go away. */ if ((error = VFS_ROOT(mp, &rootvp)) != 0) return (error); vput(rootvp); } MNT_ILOCK(mp); loop: for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 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 = TAILQ_NEXT(vp, v_nmntvnodes); VI_LOCK(vp); MNT_IUNLOCK(mp); error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); if (error) { MNT_ILOCK(mp); goto loop; } /* * Skip over a vnodes marked VV_SYSTEM. */ if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { VOP_UNLOCK(vp, 0, td); MNT_ILOCK(mp); continue; } /* * If WRITECLOSE is set, flush out unlinked but still open * files (even if open only for reading) and regular file * vnodes open for writing. */ if (flags & WRITECLOSE) { error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); VI_LOCK(vp); if ((vp->v_type == VNON || (error == 0 && vattr.va_nlink > 0)) && (vp->v_writecount == 0 || vp->v_type != VREG)) { VOP_UNLOCK(vp, LK_INTERLOCK, td); MNT_ILOCK(mp); continue; } } else VI_LOCK(vp); VOP_UNLOCK(vp, 0, td); /* * 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) { vgonel(vp, td); MNT_ILOCK(mp); 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) { if (vp->v_type != VCHR) vgonel(vp, td); else vgonechrl(vp, td); MNT_ILOCK(mp); continue; } #ifdef DIAGNOSTIC if (busyprt) vprint("vflush: busy vnode", vp); #endif VI_UNLOCK(vp); MNT_ILOCK(mp); busy++; } MNT_IUNLOCK(mp); if (rootrefs > 0 && (flags & FORCECLOSE) == 0) { /* * If just the root vnode is busy, and if its refcount * is equal to `rootrefs', then go ahead and kill it. */ VI_LOCK(rootvp); KASSERT(busy > 0, ("vflush: not busy")); KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); if (busy == 1 && rootvp->v_usecount == rootrefs) { vgonel(rootvp, td); busy = 0; } else VI_UNLOCK(rootvp); } if (busy) return (EBUSY); for (; rootrefs > 0; rootrefs--) vrele(rootvp); return (0); } /* * This moves a now (likely recyclable) vnode to the end of the * mountlist. XXX However, it is temporarily disabled until we * can clean up ffs_sync() and friends, which have loop restart * conditions which this code causes to operate O(N^2). */ static void vlruvp(struct vnode *vp) { #if 0 struct mount *mp; if ((mp = vp->v_mount) != NULL) { MNT_ILOCK(mp); TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); MNT_IUNLOCK(mp); } #endif } static void vx_lock(struct vnode *vp) { ASSERT_VI_LOCKED(vp, "vx_lock"); /* * Prevent the vnode from being recycled or brought into use while we * clean it out. */ if (vp->v_iflag & VI_XLOCK) panic("vclean: deadlock"); vp->v_iflag |= VI_XLOCK; vp->v_vxthread = curthread; } static void vx_unlock(struct vnode *vp) { ASSERT_VI_LOCKED(vp, "vx_unlock"); vp->v_iflag &= ~VI_XLOCK; vp->v_vxthread = NULL; if (vp->v_iflag & VI_XWANT) { vp->v_iflag &= ~VI_XWANT; wakeup(vp); } } /* * Disassociate the underlying filesystem from a vnode. */ static void vclean(vp, flags, td) struct vnode *vp; int flags; struct thread *td; { int active; ASSERT_VI_LOCKED(vp, "vclean"); /* * 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)) v_incr_usecount(vp, 1); /* * 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, td); /* * Clean out any buffers associated with the vnode. * If the flush fails, just toss the buffers. */ if (flags & DOCLOSE) { struct buf *bp; bp = TAILQ_FIRST(&vp->v_dirtyblkhd); if (bp != NULL) (void) vn_write_suspend_wait(vp, NULL, V_WAIT); if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) vinvalbuf(vp, 0, NOCRED, td, 0, 0); } VOP_DESTROYVOBJECT(vp); /* * 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, td); /* * 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, td); VI_LOCK(vp); if ((vp->v_iflag & VI_DOINGINACT) == 0) { vp->v_iflag |= VI_DOINGINACT; VI_UNLOCK(vp); if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) panic("vclean: cannot relock."); VOP_INACTIVE(vp, td); VI_LOCK(vp); KASSERT(vp->v_iflag & VI_DOINGINACT, ("vclean: lost VI_DOINGINACT")); vp->v_iflag &= ~VI_DOINGINACT; } VI_UNLOCK(vp); } /* * Reclaim the vnode. */ if (VOP_RECLAIM(vp, td)) panic("vclean: cannot reclaim"); if (active) { /* * Inline copy of vrele() since VOP_INACTIVE * has already been called. */ VI_LOCK(vp); v_incr_usecount(vp, -1); if (vp->v_usecount <= 0) { #ifdef INVARIANTS if (vp->v_usecount < 0 || vp->v_writecount != 0) { vprint("vclean: bad ref count", vp); panic("vclean: ref cnt"); } #endif if (VSHOULDFREE(vp)) vfree(vp); } VI_UNLOCK(vp); } /* * Delete from old mount point vnode list. */ if (vp->v_mount != NULL) insmntque(vp, (struct mount *)0); cache_purge(vp); VI_LOCK(vp); if (VSHOULDFREE(vp)) vfree(vp); /* * Done with purge, reset to the standard lock and * notify sleepers of the grim news. */ vp->v_vnlock = &vp->v_lock; vp->v_op = dead_vnodeop_p; if (vp->v_pollinfo != NULL) vn_pollgone(vp); vp->v_tag = "none"; } /* * 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; dev_t dev; KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke")); vp = ap->a_vp; KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); VI_LOCK(vp); /* * If a vgone (or vclean) is already in progress, * wait until it is done and return. */ if (vp->v_iflag & VI_XLOCK) { vp->v_iflag |= VI_XWANT; msleep(vp, VI_MTX(vp), PINOD | PDROP, "vop_revokeall", 0); return (0); } VI_UNLOCK(vp); dev = vp->v_rdev; for (;;) { mtx_lock(&spechash_mtx); vq = SLIST_FIRST(&dev->si_hlist); mtx_unlock(&spechash_mtx); if (!vq) break; vgone(vq); } 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, td) struct vnode *vp; struct mtx *inter_lkp; struct thread *td; { VI_LOCK(vp); if (vp->v_usecount == 0) { if (inter_lkp) { mtx_unlock(inter_lkp); } vgonel(vp, td); return (1); } VI_UNLOCK(vp); return (0); } /* * Eliminate all activity associated with a vnode * in preparation for reuse. */ void vgone(vp) register struct vnode *vp; { struct thread *td = curthread; /* XXX */ VI_LOCK(vp); vgonel(vp, td); } /* * Disassociate a character device from the its underlying filesystem and * attach it to spec. This is for use when the chr device is still active * and the filesystem is going away. */ static void vgonechrl(struct vnode *vp, struct thread *td) { ASSERT_VI_LOCKED(vp, "vgonechrl"); vx_lock(vp); /* * This is a custom version of vclean() which does not tearm down * the bufs or vm objects held by this vnode. This allows filesystems * to continue using devices which were discovered via another * filesystem that has been unmounted. */ if (vp->v_usecount != 0) { v_incr_usecount(vp, 1); /* * Ensure that no other activity can occur while the * underlying object is being cleaned out. */ VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td); /* * 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, td); vp->v_vnlock = &vp->v_lock; vp->v_tag = "orphanchr"; vp->v_op = spec_vnodeop_p; if (vp->v_mount != NULL) insmntque(vp, (struct mount *)0); cache_purge(vp); vrele(vp); VI_LOCK(vp); } else vclean(vp, 0, td); vp->v_op = spec_vnodeop_p; vx_unlock(vp); VI_UNLOCK(vp); } /* * vgone, with the vp interlock held. */ void vgonel(vp, td) struct vnode *vp; struct thread *td; { /* * If a vgone (or vclean) is already in progress, * wait until it is done and return. */ ASSERT_VI_LOCKED(vp, "vgonel"); if (vp->v_iflag & VI_XLOCK) { vp->v_iflag |= VI_XWANT; msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); return; } vx_lock(vp); /* * Clean out the filesystem specific data. */ vclean(vp, DOCLOSE, td); VI_UNLOCK(vp); /* * If special device, remove it from special device alias list * if it is on one. */ VI_LOCK(vp); if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) { mtx_lock(&spechash_mtx); SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); vp->v_rdev->si_usecount -= vp->v_usecount; mtx_unlock(&spechash_mtx); vp->v_rdev = 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 * VDOOMED flag 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_iflag & VI_DOOMED)) { mtx_lock(&vnode_free_list_mtx); if (vp->v_iflag & VI_FREE) { TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); } else { vp->v_iflag |= VI_FREE; freevnodes++; } TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); mtx_unlock(&vnode_free_list_mtx); } vp->v_type = VBAD; vx_unlock(vp); VI_UNLOCK(vp); } /* * Lookup a vnode by device number. */ int vfinddev(dev, type, vpp) dev_t dev; enum vtype type; struct vnode **vpp; { struct vnode *vp; mtx_lock(&spechash_mtx); SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { if (type == vp->v_type) { *vpp = vp; mtx_unlock(&spechash_mtx); return (1); } } mtx_unlock(&spechash_mtx); return (0); } /* * Calculate the total number of references to a special device. */ int vcount(vp) struct vnode *vp; { int count; mtx_lock(&spechash_mtx); count = vp->v_rdev->si_usecount; mtx_unlock(&spechash_mtx); return (count); } /* * Same as above, but using the dev_t as argument */ int count_dev(dev) dev_t dev; { int count; mtx_lock(&spechash_mtx); count = dev->si_usecount; mtx_unlock(&spechash_mtx); 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; struct vnode *vp; { char buf[96]; if (label != NULL) printf("%s: %p: ", label, (void *)vp); else printf("%p: ", (void *)vp); printf("tag %s, type %s, usecount %d, writecount %d, refcount %d,", vp->v_tag, typename[vp->v_type], vp->v_usecount, vp->v_writecount, vp->v_holdcnt); buf[0] = '\0'; if (vp->v_vflag & VV_ROOT) strcat(buf, "|VV_ROOT"); if (vp->v_vflag & VV_TEXT) strcat(buf, "|VV_TEXT"); if (vp->v_vflag & VV_SYSTEM) strcat(buf, "|VV_SYSTEM"); if (vp->v_iflag & VI_XLOCK) strcat(buf, "|VI_XLOCK"); if (vp->v_iflag & VI_XWANT) strcat(buf, "|VI_XWANT"); if (vp->v_iflag & VI_BWAIT) strcat(buf, "|VI_BWAIT"); if (vp->v_iflag & VI_DOOMED) strcat(buf, "|VI_DOOMED"); if (vp->v_iflag & VI_FREE) strcat(buf, "|VI_FREE"); if (vp->v_vflag & VV_OBJBUF) strcat(buf, "|VV_OBJBUF"); if (buf[0] != '\0') printf(" flags (%s),", &buf[1]); lockmgr_printinfo(vp->v_vnlock); printf("\n"); if (vp->v_data != NULL) VOP_PRINT(vp); } #ifdef DDB #include /* * List all of the locked vnodes in the system. * Called when debugging the kernel. */ DB_SHOW_COMMAND(lockedvnods, lockedvnodes) { struct mount *mp, *nmp; struct vnode *vp; /* * Note: because this is DDB, we can't obey the locking semantics * for these structures, which means we could catch an inconsistent * state and dereference a nasty pointer. Not much to be done * about that. */ printf("Locked vnodes\n"); for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { nmp = TAILQ_NEXT(mp, mnt_list); TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { if (VOP_ISLOCKED(vp, NULL)) vprint(NULL, vp); } nmp = TAILQ_NEXT(mp, mnt_list); } } #endif /* * Fill in a struct xvfsconf based on a struct vfsconf. */ static void vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) { strcpy(xvfsp->vfc_name, vfsp->vfc_name); xvfsp->vfc_typenum = vfsp->vfc_typenum; xvfsp->vfc_refcount = vfsp->vfc_refcount; xvfsp->vfc_flags = vfsp->vfc_flags; /* * These are unused in userland, we keep them * to not break binary compatibility. */ xvfsp->vfc_vfsops = NULL; xvfsp->vfc_next = NULL; } static int sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) { struct vfsconf *vfsp; struct xvfsconf *xvfsp; int cnt, error, i; cnt = 0; for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) cnt++; xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); /* * Handle the race that we will have here when struct vfsconf * will be locked down by using both cnt and checking vfc_next * against NULL to determine the end of the loop. The race will * happen because we will have to unlock before calling malloc(). * We are protected by Giant for now. */ i = 0; for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { vfsconf2x(vfsp, xvfsp + i); i++; } error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); free(xvfsp, M_TEMP); return (error); } SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, "S,xvfsconf", "List of all configured filesystems"); /* * Top level filesystem related information gathering. */ static int sysctl_ovfs_conf(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; struct xvfsconf xvfsp; printf("WARNING: userland calling deprecated sysctl, " "please rebuild world\n"); #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 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); vfsconf2x(vfsp, &xvfsp); return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); } return (EOPNOTSUPP); } SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, 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 */ #define KINFO_VNODESLOP 10 #ifdef notyet /* * Dump vnode list (via sysctl). */ /* ARGSUSED */ static int sysctl_vnode(SYSCTL_HANDLER_ARGS) { struct xvnode *xvn; struct thread *td = req->td; struct mount *mp; struct vnode *vp; int error, len, n; /* * Stale numvnodes access is not fatal here. */ req->lock = 0; len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; if (!req->oldptr) /* Make an estimate */ return (SYSCTL_OUT(req, 0, len)); sysctl_wire_old_buffer(req, 0); xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); n = 0; mtx_lock(&mountlist_mtx); TAILQ_FOREACH(mp, &mountlist, mnt_list) { if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) continue; MNT_ILOCK(mp); TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { if (n == len) break; vref(vp); xvn[n].xv_size = sizeof *xvn; xvn[n].xv_vnode = vp; #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field XV_COPY(usecount); XV_COPY(writecount); XV_COPY(holdcnt); XV_COPY(id); XV_COPY(mount); XV_COPY(numoutput); XV_COPY(type); #undef XV_COPY xvn[n].xv_flag = vp->v_vflag; switch (vp->v_type) { case VREG: case VDIR: case VLNK: xvn[n].xv_dev = vp->v_cachedfs; xvn[n].xv_ino = vp->v_cachedid; break; case VBLK: case VCHR: if (vp->v_rdev == NULL) { vrele(vp); continue; } xvn[n].xv_dev = dev2udev(vp->v_rdev); break; case VSOCK: xvn[n].xv_socket = vp->v_socket; break; case VFIFO: xvn[n].xv_fifo = vp->v_fifoinfo; break; case VNON: case VBAD: default: /* shouldn't happen? */ vrele(vp); continue; } vrele(vp); ++n; } MNT_IUNLOCK(mp); mtx_lock(&mountlist_mtx); vfs_unbusy(mp, td); if (n == len) break; } mtx_unlock(&mountlist_mtx); error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); free(xvn, M_TEMP); return (error); } SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0, sysctl_vnode, "S,xvnode", ""); #endif /* * Check to see if a filesystem is mounted on a block device. */ int vfs_mountedon(vp) struct vnode *vp; { if (vp->v_rdev->si_mountpoint != NULL) return (EBUSY); return (0); } /* * Unmount all filesystems. The list is traversed in reverse order * of mounting to avoid dependencies. */ void vfs_unmountall() { struct mount *mp; struct thread *td; int error; if (curthread != NULL) td = curthread; else td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ /* * Since this only runs when rebooting, it is not interlocked. */ while(!TAILQ_EMPTY(&mountlist)) { mp = TAILQ_LAST(&mountlist, mntlist); error = dounmount(mp, MNT_FORCE, td); if (error) { TAILQ_REMOVE(&mountlist, mp, mnt_list); printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); if (error == EBUSY) printf("BUSY)\n"); else printf("%d)\n", error); } else { /* The unmount has removed mp from the mountlist */ } } } /* * 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 tries; GIANT_REQUIRED; tries = 5; MNT_ILOCK(mp); loop: for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) { if (vp->v_mount != mp) { if (--tries > 0) goto loop; break; } nvp = TAILQ_NEXT(vp, v_nmntvnodes); VI_LOCK(vp); if (vp->v_iflag & VI_XLOCK) { VI_UNLOCK(vp); continue; } if ((vp->v_iflag & VI_OBJDIRTY) && (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { MNT_IUNLOCK(mp); if (!vget(vp, LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, curthread)) { if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ vput(vp); MNT_ILOCK(mp); continue; } if (VOP_GETVOBJECT(vp, &obj) == 0) { VM_OBJECT_LOCK(obj); vm_object_page_clean(obj, 0, 0, flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC); VM_OBJECT_UNLOCK(obj); } vput(vp); } MNT_ILOCK(mp); if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { if (--tries > 0) goto loop; break; } } else VI_UNLOCK(vp); } MNT_IUNLOCK(mp); } /* * 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, td, cred) struct vnode *vp; struct thread *td; struct ucred *cred; { GIANT_REQUIRED; return (VOP_CREATEVOBJECT(vp, cred, td)); } /* * Mark a vnode as free, putting it up for recycling. */ void vfree(vp) struct vnode *vp; { ASSERT_VI_LOCKED(vp, "vfree"); mtx_lock(&vnode_free_list_mtx); KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); if (vp->v_iflag & VI_AGE) { TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); } else { TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); } freevnodes++; mtx_unlock(&vnode_free_list_mtx); vp->v_iflag &= ~VI_AGE; vp->v_iflag |= VI_FREE; } /* * Opposite of vfree() - mark a vnode as in use. */ void vbusy(vp) struct vnode *vp; { ASSERT_VI_LOCKED(vp, "vbusy"); KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); mtx_lock(&vnode_free_list_mtx); TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); freevnodes--; mtx_unlock(&vnode_free_list_mtx); vp->v_iflag &= ~(VI_FREE|VI_AGE); } /* * 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, td, events) struct vnode *vp; struct thread *td; short events; { if (vp->v_pollinfo == NULL) v_addpollinfo(vp); mtx_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; mtx_unlock(&vp->v_pollinfo->vpi_lock); return events; } vp->v_pollinfo->vpi_events |= events; selrecord(td, &vp->v_pollinfo->vpi_selinfo); mtx_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; { if (vp->v_pollinfo == NULL) v_addpollinfo(vp); mtx_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; selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); } mtx_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; { mtx_lock(&vp->v_pollinfo->vpi_lock); VN_KNOTE(vp, NOTE_REVOKE); if (vp->v_pollinfo->vpi_events) { vp->v_pollinfo->vpi_events = 0; selwakeuppri(&vp->v_pollinfo->vpi_selinfo, PRIBIO); } mtx_unlock(&vp->v_pollinfo->vpi_lock); } /* * Routine to create and manage a filesystem syncer vnode. */ #define sync_close ((int (*)(struct vop_close_args *))nullop) static int sync_fsync(struct vop_fsync_args *); static int sync_inactive(struct vop_inactive_args *); static int sync_reclaim(struct vop_reclaim_args *); 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 *) vop_stdlock }, /* lock */ { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* 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("syncer", 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; } VI_LOCK(vp); vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); VI_UNLOCK(vp); 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 thread *a_td; } */ *ap; { struct vnode *syncvp = ap->a_vp; struct mount *mp = syncvp->v_mount; struct thread *td = ap->a_td; int error, 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. */ VI_LOCK(syncvp); vn_syncer_add_to_worklist(syncvp, syncdelay); VI_UNLOCK(syncvp); /* * Walk the list of vnodes pushing all that are dirty and * not already on the sync list. */ mtx_lock(&mountlist_mtx); if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { mtx_unlock(&mountlist_mtx); return (0); } if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { vfs_unbusy(mp, td); return (0); } asyncflag = mp->mnt_flag & MNT_ASYNC; mp->mnt_flag &= ~MNT_ASYNC; vfs_msync(mp, MNT_NOWAIT); error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); if (asyncflag) mp->mnt_flag |= MNT_ASYNC; vn_finished_write(mp); vfs_unbusy(mp, td); return (error); } /* * The syncer vnode is no referenced. */ static int sync_inactive(ap) struct vop_inactive_args /* { struct vnode *a_vp; struct thread *a_td; } */ *ap; { VOP_UNLOCK(ap->a_vp, 0, ap->a_td); vgone(ap->a_vp); return (0); } /* * The syncer vnode is no longer needed and is being decommissioned. * * Modifications to the worklist must be protected by sync_mtx. */ static int sync_reclaim(ap) struct vop_reclaim_args /* { struct vnode *a_vp; } */ *ap; { struct vnode *vp = ap->a_vp; VI_LOCK(vp); vp->v_mount->mnt_syncer = NULL; if (vp->v_iflag & VI_ONWORKLST) { mtx_lock(&sync_mtx); LIST_REMOVE(vp, v_synclist); mtx_unlock(&sync_mtx); vp->v_iflag &= ~VI_ONWORKLST; } VI_UNLOCK(vp); return (0); } /* * extract the dev_t from a VCHR */ dev_t vn_todev(vp) struct vnode *vp; { if (vp->v_type != VCHR) return (NODEV); return (vp->v_rdev); } /* * Check if vnode represents a disk device */ int vn_isdisk(vp, errp) struct vnode *vp; int *errp; { int error; error = 0; if (vp->v_type != VCHR) error = ENOTBLK; else if (vp->v_rdev == NULL) error = ENXIO; else if (!(devsw(vp->v_rdev)->d_flags & D_DISK)) error = ENOTBLK; if (errp != NULL) *errp = error; return (error == 0); } /* * Free data allocated by namei(); see namei(9) for details. */ void NDFREE(ndp, flags) struct nameidata *ndp; const u_int flags; { if (!(flags & NDF_NO_FREE_PNBUF) && (ndp->ni_cnd.cn_flags & HASBUF)) { uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); ndp->ni_cnd.cn_flags &= ~HASBUF; } if (!(flags & NDF_NO_DVP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKPARENT) && ndp->ni_dvp != ndp->ni_vp) VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); if (!(flags & NDF_NO_DVP_RELE) && (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { vrele(ndp->ni_dvp); ndp->ni_dvp = NULL; } if (!(flags & NDF_NO_VP_UNLOCK) && (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); if (!(flags & NDF_NO_VP_RELE) && ndp->ni_vp) { vrele(ndp->ni_vp); ndp->ni_vp = NULL; } if (!(flags & NDF_NO_STARTDIR_RELE) && (ndp->ni_cnd.cn_flags & SAVESTART)) { vrele(ndp->ni_startdir); ndp->ni_startdir = NULL; } } /* * Common filesystem object access control check routine. Accepts a * vnode's type, "mode", uid and gid, requested access mode, credentials, * and optional call-by-reference privused argument allowing vaccess() * to indicate to the caller whether privilege was used to satisfy the * request (obsoleted). Returns 0 on success, or an errno on failure. */ int vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) enum vtype type; mode_t file_mode; uid_t file_uid; gid_t file_gid; mode_t acc_mode; struct ucred *cred; int *privused; { mode_t dac_granted; #ifdef CAPABILITIES mode_t cap_granted; #endif /* * Look for a normal, non-privileged way to access the file/directory * as requested. If it exists, go with that. */ if (privused != NULL) *privused = 0; dac_granted = 0; /* Check the owner. */ if (cred->cr_uid == file_uid) { dac_granted |= VADMIN; if (file_mode & S_IXUSR) dac_granted |= VEXEC; if (file_mode & S_IRUSR) dac_granted |= VREAD; if (file_mode & S_IWUSR) dac_granted |= (VWRITE | VAPPEND); if ((acc_mode & dac_granted) == acc_mode) return (0); goto privcheck; } /* Otherwise, check the groups (first match) */ if (groupmember(file_gid, cred)) { if (file_mode & S_IXGRP) dac_granted |= VEXEC; if (file_mode & S_IRGRP) dac_granted |= VREAD; if (file_mode & S_IWGRP) dac_granted |= (VWRITE | VAPPEND); if ((acc_mode & dac_granted) == acc_mode) return (0); goto privcheck; } /* Otherwise, check everyone else. */ if (file_mode & S_IXOTH) dac_granted |= VEXEC; if (file_mode & S_IROTH) dac_granted |= VREAD; if (file_mode & S_IWOTH) dac_granted |= (VWRITE | VAPPEND); if ((acc_mode & dac_granted) == acc_mode) return (0); privcheck: if (!suser_cred(cred, PRISON_ROOT)) { /* XXX audit: privilege used */ if (privused != NULL) *privused = 1; return (0); } #ifdef CAPABILITIES /* * Build a capability mask to determine if the set of capabilities * satisfies the requirements when combined with the granted mask * from above. * For each capability, if the capability is required, bitwise * or the request type onto the cap_granted mask. */ cap_granted = 0; if (type == VDIR) { /* * For directories, use CAP_DAC_READ_SEARCH to satisfy * VEXEC requests, instead of CAP_DAC_EXECUTE. */ if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) cap_granted |= VEXEC; } else { if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) cap_granted |= VEXEC; } if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) cap_granted |= VREAD; if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) cap_granted |= (VWRITE | VAPPEND); if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) cap_granted |= VADMIN; if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { /* XXX audit: privilege used */ if (privused != NULL) *privused = 1; return (0); } #endif return ((acc_mode & VADMIN) ? EPERM : EACCES); } /* * Credential check based on process requesting service, and per-attribute * permissions. */ int extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred, struct thread *td, int access) { /* * Kernel-invoked always succeeds. */ if (cred == NOCRED) return (0); /* * Do not allow privileged processes in jail to directly * manipulate system attributes. * * XXX What capability should apply here? * Probably CAP_SYS_SETFFLAG. */ switch (attrnamespace) { case EXTATTR_NAMESPACE_SYSTEM: /* Potentially should be: return (EPERM); */ return (suser_cred(cred, 0)); case EXTATTR_NAMESPACE_USER: return (VOP_ACCESS(vp, access, cred, td)); default: return (EPERM); } }