/*- * 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. * 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 #include #include #include #include #include #include #include static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); static void delmntque(struct vnode *vp); static void insmntque(struct vnode *vp, struct mount *mp); static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, int slptimeo); static void syncer_shutdown(void *arg, int howto); static int vtryrecycle(struct vnode *vp); static void vbusy(struct vnode *vp); static void vdropl(struct vnode *vp); static void vinactive(struct vnode *, struct thread *); static void v_incr_usecount(struct vnode *); static void v_decr_usecount(struct vnode *); static void v_decr_useonly(struct vnode *); static void vfree(struct vnode *); static void vnlru_free(int); static void vdestroy(struct vnode *); static void vgonel(struct vnode *); static void vfs_knllock(void *arg); static void vfs_knlunlock(void *arg); static int vfs_knllocked(void *arg); /* * Enable Giant pushdown based on whether or not the vm is mpsafe in this * build. Without mpsafevm the buffer cache can not run Giant free. */ #if defined(__alpha__) || defined(__amd64__) || defined(__i386__) || \ defined(__ia64__) || defined(__sparc64__) int mpsafe_vfs = 1; #else int mpsafe_vfs; #endif TUNABLE_INT("debug.mpsafevfs", &mpsafe_vfs); SYSCTL_INT(_debug, OID_AUTO, mpsafevfs, CTLFLAG_RD, &mpsafe_vfs, 0, "MPSAFE VFS"); /* * 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; /* * Free vnode target. Free vnodes may simply be files which have been stat'd * but not read. This is somewhat common, and a small cache of such files * should be kept to avoid recreation costs. */ static u_long wantfreevnodes; 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, ""); /* * 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; /* 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, bufobj); static struct synclist *syncer_workitem_pending; /* * The sync_mtx protects: * bo->bo_synclist * sync_vnode_count * syncer_delayno * syncer_state * syncer_workitem_pending * syncer_worklist_len * 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, ""); /* * When shutting down the syncer, run it at four times normal speed. */ #define SYNCER_SHUTDOWN_SPEEDUP 4 static int sync_vnode_count; static int syncer_worklist_len; static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY } syncer_state; /* * 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"); SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, &wantfreevnodes, 0, "Minimum number of vnodes (legacy)"); 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 *); /* * Macros to control when a vnode is freed and recycled. All require * the vnode interlock. */ #define VCANRECYCLE(vp) (((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) #define VSHOULDFREE(vp) (!((vp)->v_iflag & VI_FREE) && !(vp)->v_holdcnt) #define VSHOULDBUSY(vp) (((vp)->v_iflag & VI_FREE) && (vp)->v_holdcnt) /* * Initialize the vnode management data structures. */ #ifndef MAXVNODES_MAX #define MAXVNODES_MAX 100000 #endif 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)))); if (desiredvnodes > MAXVNODES_MAX) { if (bootverbose) printf("Reducing kern.maxvnodes %d -> %d\n", desiredvnodes, MAXVNODES_MAX); desiredvnodes = MAXVNODES_MAX; } wantfreevnodes = desiredvnodes / 4; mtx_init(&mntid_mtx, "mntid", 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; MNT_ILOCK(mp); if (mp->mnt_kern_flag & MNTK_UNMOUNT) { if (flags & LK_NOWAIT) { MNT_IUNLOCK(mp); return (ENOENT); } if (interlkp) mtx_unlock(interlkp); 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, MNT_MTX(mp), PVFS|PDROP, "vfs_busy", 0); if (interlkp) mtx_lock(interlkp); return (ENOENT); } if (interlkp) mtx_unlock(interlkp); lkflags = LK_SHARED | LK_INTERLOCK; if (lockmgr(&mp->mnt_lock, lkflags, MNT_MTX(mp), 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; { 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); } /* * Check if a user can access priveledged mount options. */ int vfs_suser(struct mount *mp, struct thread *td) { int error; if ((mp->mnt_flag & MNT_USER) == 0 || mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { if ((error = suser(td)) != 0) return (error); } return (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] = makedev(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) 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 thread *td; 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; td = curthread; vn_start_write(NULL, &mp, V_WAIT); 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); --count; if (!VI_TRYLOCK(vp)) goto next_iter; /* * If it's been deconstructed already, it's still * referenced, or it exceeds the trigger, skip it. */ if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL && vp->v_object->resident_page_count > trigger)) { VI_UNLOCK(vp); goto next_iter; } MNT_IUNLOCK(mp); vholdl(vp); if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT, td)) { vdrop(vp); goto next_iter_mntunlocked; } VI_LOCK(vp); /* * v_usecount may have been bumped after VOP_LOCK() dropped * the vnode interlock and before it was locked again. * * It is not necessary to recheck VI_DOOMED because it can * only be set by another thread that holds both the vnode * lock and vnode interlock. If another thread has the * vnode lock before we get to VOP_LOCK() and obtains the * vnode interlock after VOP_LOCK() drops the vnode * interlock, the other thread will be unable to drop the * vnode lock before our VOP_LOCK() call fails. */ if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) || (vp->v_object != NULL && vp->v_object->resident_page_count > trigger)) { VOP_UNLOCK(vp, LK_INTERLOCK, td); goto next_iter_mntunlocked; } KASSERT((vp->v_iflag & VI_DOOMED) == 0, ("VI_DOOMED unexpectedly detected in vlrureclaim()")); vgonel(vp); VOP_UNLOCK(vp, 0, td); vdropl(vp); done++; next_iter_mntunlocked: if ((count % 256) != 0) goto relock_mnt; goto yield; next_iter: if ((count % 256) != 0) continue; MNT_IUNLOCK(mp); yield: uio_yield(); relock_mnt: MNT_ILOCK(mp); } MNT_IUNLOCK(mp); vn_finished_write(mp); return done; } /* * Attempt to keep the free list at wantfreevnodes length. */ static void vnlru_free(int count) { struct vnode *vp; mtx_assert(&vnode_free_list_mtx, MA_OWNED); for (; count > 0; count--) { vp = TAILQ_FIRST(&vnode_free_list); /* * The list can be modified while the free_list_mtx * has been dropped and vp could be NULL here. */ if (!vp) break; VNASSERT(vp->v_op != NULL, vp, ("vnlru_free: vnode already reclaimed.")); TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); /* * Don't recycle if we can't get the interlock. */ if (!VI_TRYLOCK(vp)) { TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); continue; } VNASSERT(VCANRECYCLE(vp), vp, ("vp inconsistent on freelist")); freevnodes--; vp->v_iflag &= ~VI_FREE; vholdl(vp); mtx_unlock(&vnode_free_list_mtx); VI_UNLOCK(vp); vtryrecycle(vp); /* * If the recycled succeeded this vdrop will actually free * the vnode. If not it will simply place it back on * the free list. */ vdrop(vp); mtx_lock(&vnode_free_list_mtx); } } /* * 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); 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 (freevnodes > wantfreevnodes) vnlru_free(freevnodes - wantfreevnodes); if (numvnodes <= desiredvnodes * 9 / 10) { vnlruproc_sig = 0; wakeup(&vnlruproc_sig); msleep(vnlruproc, &vnode_free_list_mtx, PVFS|PDROP, "vlruwt", hz); continue; } mtx_unlock(&vnode_free_list_mtx); done = 0; mtx_lock(&mountlist_mtx); for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { int vfsunlocked; if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { nmp = TAILQ_NEXT(mp, mnt_list); continue; } if (!VFS_NEEDSGIANT(mp)) { mtx_unlock(&Giant); vfsunlocked = 1; } else vfsunlocked = 0; done += vlrureclaim(mp); if (vfsunlocked) mtx_lock(&Giant); 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); } else uio_yield(); } } 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. */ static void vdestroy(struct vnode *vp) { struct bufobj *bo; CTR1(KTR_VFS, "vdestroy vp %p", vp); mtx_lock(&vnode_free_list_mtx); numvnodes--; mtx_unlock(&vnode_free_list_mtx); bo = &vp->v_bufobj; VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("cleaned vnode still on the free list.")); VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't")); VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count")); VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count")); VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count")); VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's")); VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0")); VNASSERT(bo->bo_clean.bv_root == NULL, vp, ("cleanblkroot not NULL")); VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); VNASSERT(bo->bo_dirty.bv_root == NULL, vp, ("dirtyblkroot not NULL")); VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); VI_UNLOCK(vp); #ifdef MAC mac_destroy_vnode(vp); #endif if (vp->v_pollinfo != NULL) { knlist_destroy(&vp->v_pollinfo->vpi_selinfo.si_note); mtx_destroy(&vp->v_pollinfo->vpi_lock); uma_zfree(vnodepoll_zone, vp->v_pollinfo); } #ifdef INVARIANTS /* XXX Elsewhere we can detect an already freed vnode via NULL v_op. */ vp->v_op = NULL; #endif lockdestroy(vp->v_vnlock); mtx_destroy(&vp->v_interlock); uma_zfree(vnode_zone, vp); } /* * Try to recycle a freed vnode. We abort if anyone picks up a reference * before we actually vgone(). This function must be called with the vnode * held to prevent the vnode from being returned to the free list midway * through vgone(). */ static int vtryrecycle(struct vnode *vp) { struct thread *td = curthread; struct mount *vnmp; CTR1(KTR_VFS, "vtryrecycle: trying vp %p", vp); VNASSERT(vp->v_holdcnt, vp, ("vtryrecycle: Recycling vp %p without a reference.", vp)); /* * This vnode may found and locked via some other list, if so we * can't recycle it yet. */ if (VOP_LOCK(vp, 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) { VOP_UNLOCK(vp, 0, td); return (EBUSY); } /* * 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 DOOMED via vgonel() so that anyone who does find it * will skip over it. */ VI_LOCK(vp); if (vp->v_usecount) { VOP_UNLOCK(vp, LK_INTERLOCK, td); vn_finished_write(vnmp); return (EBUSY); } if ((vp->v_iflag & VI_DOOMED) == 0) vgonel(vp); VOP_UNLOCK(vp, LK_INTERLOCK, td); vn_finished_write(vnmp); CTR1(KTR_VFS, "vtryrecycle: recycled vp %p", vp); return (0); } /* * Return the next vnode from the free list. */ int getnewvnode(tag, mp, vops, vpp) const char *tag; struct mount *mp; struct vop_vector *vops; struct vnode **vpp; { struct vnode *vp = NULL; struct bufobj *bo; mtx_lock(&vnode_free_list_mtx); /* * Lend our context to reclaim vnodes if they've exceeded the max. */ if (freevnodes > wantfreevnodes) vnlru_free(1); /* * Wait for available vnodes. */ if (numvnodes > desiredvnodes) { if (vnlruproc_sig == 0) { vnlruproc_sig = 1; /* avoid unnecessary wakeups */ wakeup(vnlruproc); } msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, "vlruwk", hz); #if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ if (numvnodes > desiredvnodes) { mtx_unlock(&vnode_free_list_mtx); return (ENFILE); } #endif } numvnodes++; mtx_unlock(&vnode_free_list_mtx); vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); /* * Setup locks. */ vp->v_vnlock = &vp->v_lock; mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); /* * By default, don't allow shared locks unless filesystems * opt-in. */ lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOSHARE); /* * Initialize bufobj. */ bo = &vp->v_bufobj; bo->__bo_vnode = vp; bo->bo_mtx = &vp->v_interlock; bo->bo_ops = &buf_ops_bio; bo->bo_private = vp; TAILQ_INIT(&bo->bo_clean.bv_hd); TAILQ_INIT(&bo->bo_dirty.bv_hd); /* * Initialize namecache. */ LIST_INIT(&vp->v_cache_src); TAILQ_INIT(&vp->v_cache_dst); /* * Finalize various vnode identity bits. */ vp->v_type = VNON; vp->v_tag = tag; vp->v_op = vops; v_incr_usecount(vp); vp->v_data = 0; #ifdef MAC mac_init_vnode(vp); if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) mac_associate_vnode_singlelabel(mp, vp); else if (mp == NULL) printf("NULL mp in getnewvnode()\n"); #endif delmntque(vp); if (mp != NULL) { insmntque(vp, mp); bo->bo_bsize = mp->mnt_stat.f_iosize; if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) vp->v_vflag |= VV_NOKNOTE; } CTR2(KTR_VFS, "getnewvnode: mp %p vp %p", mp, vp); *vpp = vp; return (0); } /* * Delete from old mount point vnode list, if on one. */ static void delmntque(struct vnode *vp) { struct mount *mp; if (vp->v_mount == NULL) return; mp = vp->v_mount; MNT_ILOCK(mp); vp->v_mount = NULL; VNASSERT(mp->mnt_nvnodelistsize > 0, vp, ("bad mount point vnode list size")); TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); mp->mnt_nvnodelistsize--; MNT_IUNLOCK(mp); } /* * Insert into list of vnodes for the new mount point, if available. */ static void insmntque(struct vnode *vp, struct mount *mp) { vp->v_mount = mp; VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); MNT_ILOCK(vp->v_mount); TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); mp->mnt_nvnodelistsize++; MNT_IUNLOCK(vp->v_mount); } /* * Flush out and invalidate all buffers associated with a bufobj * Called with the underlying object locked. */ int bufobj_invalbuf(struct bufobj *bo, int flags, struct thread *td, int slpflag, int slptimeo) { int error; BO_LOCK(bo); if (flags & V_SAVE) { error = bufobj_wwait(bo, slpflag, slptimeo); if (error) { BO_UNLOCK(bo); return (error); } if (bo->bo_dirty.bv_cnt > 0) { BO_UNLOCK(bo); if ((error = BO_SYNC(bo, MNT_WAIT, td)) != 0) return (error); /* * XXX We could save a lock/unlock if this was only * enabled under INVARIANTS */ BO_LOCK(bo); if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0) 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. */ do { error = flushbuflist(&bo->bo_clean, flags, bo, slpflag, slptimeo); if (error == 0) error = flushbuflist(&bo->bo_dirty, flags, bo, slpflag, slptimeo); if (error != 0 && error != EAGAIN) { BO_UNLOCK(bo); return (error); } } while (error != 0); /* * 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 { bufobj_wwait(bo, 0, 0); BO_UNLOCK(bo); if (bo->bo_object != NULL) { VM_OBJECT_LOCK(bo->bo_object); vm_object_pip_wait(bo->bo_object, "bovlbx"); VM_OBJECT_UNLOCK(bo->bo_object); } BO_LOCK(bo); } while (bo->bo_numoutput > 0); BO_UNLOCK(bo); /* * Destroy the copy in the VM cache, too. */ if (bo->bo_object != NULL) { VM_OBJECT_LOCK(bo->bo_object); vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? TRUE : FALSE); VM_OBJECT_UNLOCK(bo->bo_object); } #ifdef INVARIANTS BO_LOCK(bo); if ((flags & (V_ALT | V_NORMAL)) == 0 && (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0)) panic("vinvalbuf: flush failed"); BO_UNLOCK(bo); #endif return (0); } /* * Flush out and invalidate all buffers associated with a vnode. * Called with the underlying object locked. */ int vinvalbuf(struct vnode *vp, int flags, struct thread *td, int slpflag, int slptimeo) { CTR2(KTR_VFS, "vinvalbuf vp %p flags %d", vp, flags); ASSERT_VOP_LOCKED(vp, "vinvalbuf"); return (bufobj_invalbuf(&vp->v_bufobj, flags, td, slpflag, slptimeo)); } /* * Flush out buffers on the specified list. * */ static int flushbuflist(bufv, flags, bo, slpflag, slptimeo) struct bufv *bufv; int flags; struct bufobj *bo; int slpflag, slptimeo; { struct buf *bp, *nbp; int retval, error; daddr_t lblkno; b_xflags_t xflags; ASSERT_BO_LOCKED(bo); retval = 0; TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) { if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { continue; } lblkno = 0; xflags = 0; if (nbp != NULL) { lblkno = nbp->b_lblkno; xflags = nbp->b_xflags & (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN); } retval = EAGAIN; error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_MTX(bo), "flushbuf", slpflag, slptimeo); if (error) { BO_LOCK(bo); return (error != ENOLCK ? error : EAGAIN); } KASSERT(bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); if (bp->b_bufobj != bo) { /* XXX: necessary ? */ BUF_UNLOCK(bp); BO_LOCK(bo); return (EAGAIN); } /* * 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. */ if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && (flags & V_SAVE)) { bremfree(bp); bp->b_flags |= B_ASYNC; bwrite(bp); BO_LOCK(bo); return (EAGAIN); /* XXX: why not loop ? */ } bremfree(bp); bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); BO_LOCK(bo); if (nbp != NULL && (nbp->b_bufobj != bo || nbp->b_lblkno != lblkno || (nbp->b_xflags & (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags)) break; /* nbp invalid */ } return (retval); } /* * 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(struct vnode *vp, struct ucred *cred, struct thread *td, off_t length, int blksize) { struct buf *bp, *nbp; int anyfreed; int trunclbn; struct bufobj *bo; CTR2(KTR_VFS, "vtruncbuf vp %p length %jd", vp, length); /* * Round up to the *next* lbn. */ trunclbn = (length + blksize - 1) / blksize; ASSERT_VOP_LOCKED(vp, "vtruncbuf"); restart: VI_LOCK(vp); bo = &vp->v_bufobj; anyfreed = 1; for (;anyfreed;) { anyfreed = 0; TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { if (bp->b_lblkno < trunclbn) continue; 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 != NULL && (((nbp->b_xflags & BX_VNCLEAN) == 0) || (nbp->b_vp != vp) || (nbp->b_flags & B_DELWRI))) { goto restart; } VI_LOCK(vp); } TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { if (bp->b_lblkno < trunclbn) continue; 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 != NULL && (((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: TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { 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; } VNASSERT((bp->b_flags & B_DELWRI), vp, ("buf(%p) on dirty queue without DELWRI", bp)); bremfree(bp); bawrite(bp); VI_LOCK(vp); goto restartsync; } } bufobj_wwait(bo, 0, 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 buf *root; struct bufv *bv; KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); ASSERT_BO_LOCKED(bp->b_bufobj); KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) != (BX_VNDIRTY|BX_VNCLEAN), ("buf_vlist_remove: Buf %p is on two lists", bp)); if (bp->b_xflags & BX_VNDIRTY) bv = &bp->b_bufobj->bo_dirty; else bv = &bp->b_bufobj->bo_clean; if (bp != bv->bv_root) { root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); KASSERT(root == bp, ("splay lookup failed in 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; } bv->bv_root = root; TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs); bv->bv_cnt--; 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 bufobj *bo, b_xflags_t xflags) { struct buf *root; struct bufv *bv; ASSERT_BO_LOCKED(bo); KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, ("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags)); bp->b_xflags |= xflags; if (xflags & BX_VNDIRTY) bv = &bo->bo_dirty; else bv = &bo->bo_clean; root = buf_splay(bp->b_lblkno, bp->b_xflags, bv->bv_root); if (root == NULL) { bp->b_left = NULL; bp->b_right = NULL; TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); } 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_bobufs); } else { bp->b_right = root->b_right; bp->b_left = root; root->b_right = NULL; TAILQ_INSERT_AFTER(&bv->bv_hd, root, bp, b_bobufs); } bv->bv_cnt++; bv->bv_root = 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 bufobj *bo, daddr_t lblkno) { struct buf *bp; ASSERT_BO_LOCKED(bo); if ((bp = bo->bo_clean.bv_root) != NULL && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); if ((bp = bo->bo_dirty.bv_root) != NULL && bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); if ((bp = bo->bo_clean.bv_root) != NULL) { bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp); if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) return (bp); } if ((bp = bo->bo_dirty.bv_root) != NULL) { bo->bo_dirty.bv_root = 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(struct vnode *vp, struct buf *bp) { VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free")); CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags); VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp, ("bgetvp: bp already attached! %p", bp)); ASSERT_VI_LOCKED(vp, "bgetvp"); vholdl(vp); bp->b_vp = vp; bp->b_bufobj = &vp->v_bufobj; /* * Insert onto list for new vnode. */ buf_vlist_add(bp, &vp->v_bufobj, BX_VNCLEAN); } /* * Disassociate a buffer from a vnode. */ void brelvp(struct buf *bp) { struct bufobj *bo; struct vnode *vp; CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); /* * Delete from old vnode list, if on one. */ vp = bp->b_vp; /* XXX */ bo = bp->b_bufobj; BO_LOCK(bo); if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) buf_vlist_remove(bp); else panic("brelvp: Buffer %p not on queue.", bp); if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { bo->bo_flag &= ~BO_ONWORKLST; mtx_lock(&sync_mtx); LIST_REMOVE(bo, bo_synclist); syncer_worklist_len--; mtx_unlock(&sync_mtx); } bp->b_vp = NULL; bp->b_bufobj = NULL; vdropl(vp); } /* * Add an item to the syncer work queue. */ static void vn_syncer_add_to_worklist(struct bufobj *bo, int delay) { int slot; ASSERT_BO_LOCKED(bo); mtx_lock(&sync_mtx); if (bo->bo_flag & BO_ONWORKLST) LIST_REMOVE(bo, bo_synclist); else { bo->bo_flag |= BO_ONWORKLST; syncer_worklist_len++; } if (delay > syncer_maxdelay - 2) delay = syncer_maxdelay - 2; slot = (syncer_delayno + delay) & syncer_mask; LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist); mtx_unlock(&sync_mtx); } static int sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS) { int error, len; mtx_lock(&sync_mtx); len = syncer_worklist_len - sync_vnode_count; mtx_unlock(&sync_mtx); error = SYSCTL_OUT(req, &len, sizeof(len)); return (error); } SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, sysctl_vfs_worklist_len, "I", "Syncer thread worklist length"); static 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) static int sync_vnode(struct bufobj *bo, struct thread *td) { struct vnode *vp; struct mount *mp; vp = bo->__bo_vnode; /* XXX */ if (VOP_ISLOCKED(vp, NULL) != 0) return (1); if (VI_TRYLOCK(vp) == 0) return (1); /* * 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); VI_UNLOCK(vp); if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { vdrop(vp); mtx_lock(&sync_mtx); return (1); } vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); (void) VOP_FSYNC(vp, MNT_LAZY, td); VOP_UNLOCK(vp, 0, td); vn_finished_write(mp); VI_LOCK(vp); if ((bo->bo_flag & BO_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(bo, syncdelay); } vdropl(vp); mtx_lock(&sync_mtx); return (0); } /* * System filesystem synchronizer daemon. */ static void sched_sync(void) { struct synclist *next; struct synclist *slp; struct bufobj *bo; long starttime; struct thread *td = FIRST_THREAD_IN_PROC(updateproc); static int dummychan; int last_work_seen; int net_worklist_len; int syncer_final_iter; int first_printf; int error; mtx_lock(&Giant); last_work_seen = 0; syncer_final_iter = 0; first_printf = 1; syncer_state = SYNCER_RUNNING; starttime = time_uptime; td->td_pflags |= TDP_NORUNNINGBUF; EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc, SHUTDOWN_PRI_LAST); for (;;) { mtx_lock(&sync_mtx); if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter == 0) { mtx_unlock(&sync_mtx); kthread_suspend_check(td->td_proc); mtx_lock(&sync_mtx); } net_worklist_len = syncer_worklist_len - sync_vnode_count; if (syncer_state != SYNCER_RUNNING && starttime != time_uptime) { if (first_printf) { printf("\nSyncing disks, vnodes remaining..."); first_printf = 0; } printf("%d ", net_worklist_len); } starttime = time_uptime; /* * Push files whose dirty time has expired. Be careful * of interrupt race on slp queue. * * Skip over empty worklist slots when shutting down. */ do { slp = &syncer_workitem_pending[syncer_delayno]; syncer_delayno += 1; if (syncer_delayno == syncer_maxdelay) syncer_delayno = 0; next = &syncer_workitem_pending[syncer_delayno]; /* * If the worklist has wrapped since the * it was emptied of all but syncer vnodes, * switch to the FINAL_DELAY state and run * for one more second. */ if (syncer_state == SYNCER_SHUTTING_DOWN && net_worklist_len == 0 && last_work_seen == syncer_delayno) { syncer_state = SYNCER_FINAL_DELAY; syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP; } } while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) && syncer_worklist_len > 0); /* * Keep track of the last time there was anything * on the worklist other than syncer vnodes. * Return to the SHUTTING_DOWN state if any * new work appears. */ if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING) last_work_seen = syncer_delayno; if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY) syncer_state = SYNCER_SHUTTING_DOWN; while ((bo = LIST_FIRST(slp)) != NULL) { error = sync_vnode(bo, td); if (error == 1) { LIST_REMOVE(bo, bo_synclist); LIST_INSERT_HEAD(next, bo, bo_synclist); continue; } } if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) syncer_final_iter--; 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); /* * Just sleep for a short period if time between * iterations when shutting down to allow some I/O * to happen. * * 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 (syncer_state != SYNCER_RUNNING) tsleep(&dummychan, PPAUSE, "syncfnl", hz / SYNCER_SHUTDOWN_SPEEDUP); else if (time_uptime == 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. */ int speedup_syncer() { struct thread *td; int ret = 0; td = FIRST_THREAD_IN_PROC(updateproc); sleepq_remove(td, &lbolt); mtx_lock(&sync_mtx); if (rushjob < syncdelay / 2) { rushjob += 1; stat_rush_requests += 1; ret = 1; } mtx_unlock(&sync_mtx); return (ret); } /* * Tell the syncer to speed up its work and run though its work * list several times, then tell it to shut down. */ static void syncer_shutdown(void *arg, int howto) { struct thread *td; if (howto & RB_NOSYNC) return; td = FIRST_THREAD_IN_PROC(updateproc); sleepq_remove(td, &lbolt); mtx_lock(&sync_mtx); syncer_state = SYNCER_SHUTTING_DOWN; rushjob = 0; mtx_unlock(&sync_mtx); kproc_shutdown(arg, howto); } /* * 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(struct buf *bp) { struct vnode *vp; struct bufobj *bo; int delay; #ifdef INVARIANTS struct bufv *bv; #endif vp = bp->b_vp; bo = bp->b_bufobj; ++reassignbufcalls; CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); /* * 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); else panic("reassignbuf: Buffer %p not on queue.", bp); /* * If dirty, put on list of dirty buffers; otherwise insert onto list * of clean buffers. */ if (bp->b_flags & B_DELWRI) { if ((bo->bo_flag & BO_ONWORKLST) == 0) { switch (vp->v_type) { case VDIR: delay = dirdelay; break; case VCHR: delay = metadelay; break; default: delay = filedelay; } vn_syncer_add_to_worklist(bo, delay); } buf_vlist_add(bp, bo, BX_VNDIRTY); } else { buf_vlist_add(bp, bo, BX_VNCLEAN); if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) { mtx_lock(&sync_mtx); LIST_REMOVE(bo, bo_synclist); syncer_worklist_len--; mtx_unlock(&sync_mtx); bo->bo_flag &= ~BO_ONWORKLST; } } #ifdef INVARIANTS bv = &bo->bo_clean; bp = TAILQ_FIRST(&bv->bv_hd); KASSERT(bp == NULL || bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); bp = TAILQ_LAST(&bv->bv_hd, buflists); KASSERT(bp == NULL || bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); bv = &bo->bo_dirty; bp = TAILQ_FIRST(&bv->bv_hd); KASSERT(bp == NULL || bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); bp = TAILQ_LAST(&bv->bv_hd, buflists); KASSERT(bp == NULL || bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); #endif VI_UNLOCK(vp); } /* * Increment the use and hold counts on the vnode, taking care to reference * the driver's usecount if this is a chardev. The vholdl() will remove * the vnode from the free list if it is presently free. Requires the * vnode interlock and returns with it held. */ static void v_incr_usecount(struct vnode *vp) { CTR3(KTR_VFS, "v_incr_usecount: vp %p holdcnt %d usecount %d\n", vp, vp->v_holdcnt, vp->v_usecount); vp->v_usecount++; if (vp->v_type == VCHR && vp->v_rdev != NULL) { dev_lock(); vp->v_rdev->si_usecount++; dev_unlock(); } vholdl(vp); } /* * Decrement the vnode use and hold count along with the driver's usecount * if this is a chardev. The vdropl() below releases the vnode interlock * as it may free the vnode. */ static void v_decr_usecount(struct vnode *vp) { CTR3(KTR_VFS, "v_decr_usecount: vp %p holdcnt %d usecount %d\n", vp, vp->v_holdcnt, vp->v_usecount); ASSERT_VI_LOCKED(vp, __FUNCTION__); VNASSERT(vp->v_usecount > 0, vp, ("v_decr_usecount: negative usecount")); vp->v_usecount--; if (vp->v_type == VCHR && vp->v_rdev != NULL) { dev_lock(); vp->v_rdev->si_usecount--; dev_unlock(); } vdropl(vp); } /* * Decrement only the use count and driver use count. This is intended to * be paired with a follow on vdropl() to release the remaining hold count. * In this way we may vgone() a vnode with a 0 usecount without risk of * having it end up on a free list because the hold count is kept above 0. */ static void v_decr_useonly(struct vnode *vp) { CTR3(KTR_VFS, "v_decr_useonly: vp %p holdcnt %d usecount %d\n", vp, vp->v_holdcnt, vp->v_usecount); ASSERT_VI_LOCKED(vp, __FUNCTION__); VNASSERT(vp->v_usecount > 0, vp, ("v_decr_useonly: negative usecount")); vp->v_usecount--; if (vp->v_type == VCHR && vp->v_rdev != NULL) { dev_lock(); vp->v_rdev->si_usecount--; dev_unlock(); } } /* * 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) struct vnode *vp; int flags; struct thread *td; { int oweinact; int oldflags; int error; error = 0; oldflags = flags; oweinact = 0; if ((flags & LK_INTERLOCK) == 0) VI_LOCK(vp); /* * If the inactive call was deferred because vput() was called * with a shared lock, we have to do it here before another thread * gets a reference to data that should be dead. */ if (vp->v_iflag & VI_OWEINACT) { if (flags & LK_NOWAIT) { VI_UNLOCK(vp); return (EBUSY); } flags &= ~LK_TYPE_MASK; flags |= LK_EXCLUSIVE; oweinact = 1; } v_incr_usecount(vp); if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { VI_LOCK(vp); /* * 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. */ v_decr_usecount(vp); return (error); } if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) panic("vget: vn_lock failed to return ENOENT\n"); if (oweinact) { VI_LOCK(vp); if (vp->v_iflag & VI_OWEINACT) vinactive(vp, td); VI_UNLOCK(vp); if ((oldflags & LK_TYPE_MASK) == 0) VOP_UNLOCK(vp, 0, td); } return (0); } /* * Increase the reference count of a vnode. */ void vref(struct vnode *vp) { VI_LOCK(vp); v_incr_usecount(vp); 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. */ VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, ("vrele: missed vn_close")); if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && vp->v_usecount == 1)) { v_decr_usecount(vp); return; } if (vp->v_usecount != 1) { #ifdef DIAGNOSTIC vprint("vrele: negative ref count", vp); #endif VI_UNLOCK(vp); panic("vrele: negative ref cnt"); } /* * We want to hold the vnode until the inactive finishes to * prevent vgone() races. We drop the use count here and the * hold count below when we're done. */ v_decr_useonly(vp); /* * 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); vinactive(vp, td); VOP_UNLOCK(vp, 0, td); } else VI_LOCK(vp); vdropl(vp); } /* * 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 */ int error; KASSERT(vp != NULL, ("vput: null vp")); ASSERT_VOP_LOCKED(vp, "vput"); VI_LOCK(vp); /* Skip this v_writecount check if we're going to panic below. */ VNASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, vp, ("vput: missed vn_close")); error = 0; if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && vp->v_usecount == 1)) { VOP_UNLOCK(vp, 0, td); v_decr_usecount(vp); return; } if (vp->v_usecount != 1) { #ifdef DIAGNOSTIC vprint("vput: negative ref count", vp); #endif panic("vput: negative ref cnt"); } /* * We want to hold the vnode until the inactive finishes to * prevent vgone() races. We drop the use count here and the * hold count below when we're done. */ v_decr_useonly(vp); vp->v_iflag |= VI_OWEINACT; if (VOP_ISLOCKED(vp, NULL) != LK_EXCLUSIVE) { error = VOP_LOCK(vp, LK_EXCLUPGRADE|LK_INTERLOCK|LK_NOWAIT, td); VI_LOCK(vp); if (error) goto done; } if (vp->v_iflag & VI_OWEINACT) vinactive(vp, td); VOP_UNLOCK(vp, 0, td); done: vdropl(vp); } /* * Somebody doesn't want the vnode recycled. */ void vhold(struct vnode *vp) { VI_LOCK(vp); vholdl(vp); VI_UNLOCK(vp); } void vholdl(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); } /* * Drop the hold count of the vnode. If this is the last reference to * the vnode we will free it if it has been vgone'd otherwise it is * placed on the free list. */ static void vdropl(struct vnode *vp) { if (vp->v_holdcnt <= 0) panic("vdrop: holdcnt %d", vp->v_holdcnt); vp->v_holdcnt--; if (vp->v_holdcnt == 0) { if (vp->v_iflag & VI_DOOMED) { vdestroy(vp); return; } else vfree(vp); } VI_UNLOCK(vp); } /* * Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT * flags. DOINGINACT prevents us from recursing in calls to vinactive. * OWEINACT tracks whether a vnode missed a call to inactive due to a * failed lock upgrade. */ static void vinactive(struct vnode *vp, struct thread *td) { ASSERT_VOP_LOCKED(vp, "vinactive"); ASSERT_VI_LOCKED(vp, "vinactive"); VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, ("vinactive: recursed on VI_DOINGINACT")); vp->v_iflag |= VI_DOINGINACT; vp->v_iflag &= ~VI_OWEINACT; VI_UNLOCK(vp); VOP_INACTIVE(vp, td); VI_LOCK(vp); VNASSERT(vp->v_iflag & VI_DOINGINACT, vp, ("vinactive: lost VI_DOINGINACT")); vp->v_iflag &= ~VI_DOINGINACT; } /* * 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(, td) * 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, td) struct mount *mp; int rootrefs; int flags; struct thread *td; { struct vnode *vp, *nvp, *rootvp = NULL; struct vattr vattr; int busy = 0, error; CTR1(KTR_VFS, "vflush: mp %p", mp); 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, LK_EXCLUSIVE, &rootvp, td)) != 0) return (error); vput(rootvp); } MNT_ILOCK(mp); loop: MNT_VNODE_FOREACH(vp, mp, nvp) { VI_LOCK(vp); vholdl(vp); MNT_IUNLOCK(mp); error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td); if (error) { vdrop(vp); 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); vdrop(vp); 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, 0, td); vdropl(vp); MNT_ILOCK(mp); continue; } } else VI_LOCK(vp); /* * With v_usecount == 0, all we need to do is clear out the * vnode data structures and we are done. * * If FORCECLOSE is set, forcibly close the vnode. */ if (vp->v_usecount == 0 || (flags & FORCECLOSE)) { VNASSERT(vp->v_usecount == 0 || (vp->v_type != VCHR && vp->v_type != VBLK), vp, ("device VNODE %p is FORCECLOSED", vp)); vgonel(vp); } else { busy++; #ifdef DIAGNOSTIC if (busyprt) vprint("vflush: busy vnode", vp); #endif } VOP_UNLOCK(vp, 0, td); vdropl(vp); MNT_ILOCK(mp); } 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")); VNASSERT(rootvp->v_usecount >= rootrefs, rootvp, ("vflush: usecount %d < rootrefs %d", rootvp->v_usecount, rootrefs)); if (busy == 1 && rootvp->v_usecount == rootrefs) { VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK, td); vgone(rootvp); VOP_UNLOCK(rootvp, 0, td); busy = 0; } else VI_UNLOCK(rootvp); } if (busy) return (EBUSY); for (; rootrefs > 0; rootrefs--) vrele(rootvp); return (0); } /* * Recycle an unused vnode to the front of the free list. */ int vrecycle(struct vnode *vp, struct thread *td) { int recycled; ASSERT_VOP_LOCKED(vp, "vrecycle"); recycled = 0; VI_LOCK(vp); if (vp->v_usecount == 0) { recycled = 1; vgonel(vp); } VI_UNLOCK(vp); return (recycled); } /* * Eliminate all activity associated with a vnode * in preparation for reuse. */ void vgone(struct vnode *vp) { VI_LOCK(vp); vgonel(vp); VI_UNLOCK(vp); } /* * vgone, with the vp interlock held. */ void vgonel(struct vnode *vp) { struct thread *td; int oweinact; int active; CTR1(KTR_VFS, "vgonel: vp %p", vp); ASSERT_VOP_LOCKED(vp, "vgonel"); ASSERT_VI_LOCKED(vp, "vgonel"); #if 0 /* XXX Need to fix ttyvp before I enable this. */ VNASSERT(vp->v_holdcnt, vp, ("vgonel: vp %p has no reference.", vp)); #endif td = curthread; /* * Don't vgonel if we're already doomed. */ if (vp->v_iflag & VI_DOOMED) return; vp->v_iflag |= VI_DOOMED; /* * Check to see if the vnode is in use. If so, we have to call * VOP_CLOSE() and VOP_INACTIVE(). */ active = vp->v_usecount; oweinact = (vp->v_iflag & VI_OWEINACT); VI_UNLOCK(vp); /* * Clean out any buffers associated with the vnode. * If the flush fails, just toss the buffers. */ if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) (void) vn_write_suspend_wait(vp, NULL, V_WAIT); if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0) vinvalbuf(vp, 0, td, 0, 0); /* * If purging an active vnode, it must be closed and * deactivated before being reclaimed. */ if (active) VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); if (oweinact || active) { VI_LOCK(vp); if ((vp->v_iflag & VI_DOINGINACT) == 0) vinactive(vp, td); VI_UNLOCK(vp); } /* * Reclaim the vnode. */ if (VOP_RECLAIM(vp, td)) panic("vgone: cannot reclaim"); VNASSERT(vp->v_object == NULL, vp, ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); /* * Delete from old mount point vnode list. */ delmntque(vp); cache_purge(vp); /* * Done with purge, reset to the standard lock and invalidate * the vnode. */ VI_LOCK(vp); vp->v_vnlock = &vp->v_lock; vp->v_op = &dead_vnodeops; vp->v_tag = "none"; vp->v_type = VBAD; } /* * Calculate the total number of references to a special device. */ int vcount(vp) struct vnode *vp; { int count; dev_lock(); count = vp->v_rdev->si_usecount; dev_unlock(); return (count); } /* * Same as above, but using the struct cdev *as argument */ int count_dev(dev) struct cdev *dev; { int count; dev_lock(); count = dev->si_usecount; dev_unlock(); return(count); } /* * Print out a description of a vnode. */ static char *typename[] = {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; void vn_printf(struct vnode *vp, const char *fmt, ...) { va_list ap; char buf[96]; va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); printf("%p: ", (void *)vp); printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]); printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n", vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere); buf[0] = '\0'; buf[1] = '\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_DOOMED) strcat(buf, "|VI_DOOMED"); if (vp->v_iflag & VI_FREE) strcat(buf, "|VI_FREE"); printf(" flags (%s)\n", buf + 1); if (mtx_owned(VI_MTX(vp))) printf(" VI_LOCKed"); if (vp->v_object != NULL) printf(" v_object %p ref %d pages %d\n", vp->v_object, vp->v_object->ref_count, vp->v_object->resident_page_count); printf(" "); 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("", 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; } /* * Top level filesystem related information gathering. */ static int sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) { struct vfsconf *vfsp; struct xvfsconf xvfsp; int error; error = 0; TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { bzero(&xvfsp, sizeof(xvfsp)); vfsconf2x(vfsp, &xvfsp); error = SYSCTL_OUT(req, &xvfsp, sizeof xvfsp); if (error) break; } return (error); } SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, "S,xvfsconf", "List of all configured filesystems"); #ifndef BURN_BRIDGES 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 */ TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) if (vfsp->vfc_typenum == name[2]) break; if (vfsp == NULL) return (EOPNOTSUPP); bzero(&xvfsp, sizeof(xvfsp)); vfsconf2x(vfsp, &xvfsp); return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); } return (EOPNOTSUPP); } static 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; TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { bzero(&ovfs, sizeof(ovfs)); 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 */ #endif /* !BURN_BRIDGES */ #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)); error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); 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; xvn[n].xv_id = 0; /* XXX compat */ #define XV_COPY(field) xvn[n].xv_##field = vp->v_##field XV_COPY(usecount); XV_COPY(writecount); XV_COPY(holdcnt); 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: 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 /* * 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; KASSERT(curthread != NULL, ("vfs_unmountall: NULL curthread")); td = curthread; /* * 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); /* * XXX: Due to the way in which we mount the root * file system off of devfs, devfs will generate a * "busy" warning when we try to unmount it before * the root. Don't print a warning as a result in * order to avoid false positive errors that may * cause needless upset. */ if (strcmp(mp->mnt_vfc->vfc_name, "devfs") != 0) { 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; tries = 5; MNT_ILOCK(mp); loop: TAILQ_FOREACH_SAFE(vp, &mp->mnt_nvnodelist, v_nmntvnodes, nvp) { if (vp->v_mount != mp) { if (--tries > 0) goto loop; break; } VI_LOCK(vp); 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; } obj = vp->v_object; if (obj != NULL) { 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); } /* * Mark a vnode as free, putting it up for recycling. */ static void vfree(struct vnode *vp) { CTR1(KTR_VFS, "vfree vp %p", vp); ASSERT_VI_LOCKED(vp, "vfree"); mtx_lock(&vnode_free_list_mtx); VNASSERT(vp->v_op != NULL, vp, ("vfree: vnode already reclaimed.")); VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, ("vnode already free")); VNASSERT(VSHOULDFREE(vp), vp, ("vfree: freeing when we shouldn't")); VNASSERT((vp->v_iflag & VI_DOOMED) == 0, vp, ("vfree: Freeing doomed vnode")); 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++; vp->v_iflag &= ~VI_AGE; vp->v_iflag |= VI_FREE; mtx_unlock(&vnode_free_list_mtx); } /* * Opposite of vfree() - mark a vnode as in use. */ static void vbusy(struct vnode *vp) { CTR1(KTR_VFS, "vbusy vp %p", vp); ASSERT_VI_LOCKED(vp, "vbusy"); VNASSERT((vp->v_iflag & VI_FREE) != 0, vp, ("vnode not free")); VNASSERT(vp->v_op != NULL, vp, ("vbusy: vnode already reclaimed.")); mtx_lock(&vnode_free_list_mtx); TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); freevnodes--; vp->v_iflag &= ~(VI_FREE|VI_AGE); mtx_unlock(&vnode_free_list_mtx); } /* * Initalize per-vnode helper structure to hold poll-related state. */ void v_addpollinfo(struct vnode *vp) { struct vpollinfo *vi; vi = uma_zalloc(vnodepoll_zone, M_WAITOK); if (vp->v_pollinfo != NULL) { uma_zfree(vnodepoll_zone, vi); return; } vp->v_pollinfo = vi; mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); knlist_init(&vp->v_pollinfo->vpi_selinfo.si_note, vp, vfs_knllock, vfs_knlunlock, vfs_knllocked); } /* * 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; } /* * 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 struct vop_vector sync_vnodeops = { .vop_bypass = VOP_EOPNOTSUPP, .vop_close = sync_close, /* close */ .vop_fsync = sync_fsync, /* fsync */ .vop_inactive = sync_inactive, /* inactive */ .vop_reclaim = sync_reclaim, /* reclaim */ .vop_lock = vop_stdlock, /* lock */ .vop_unlock = vop_stdunlock, /* unlock */ .vop_islocked = vop_stdislocked, /* islocked */ }; /* * 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_vnodeops, &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->v_bufobj, syncdelay > 0 ? next % syncdelay : 0); /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ mtx_lock(&sync_mtx); sync_vnode_count++; mtx_unlock(&sync_mtx); 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; struct bufobj *bo; /* * 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. */ bo = &syncvp->v_bufobj; BO_LOCK(bo); vn_syncer_add_to_worklist(bo, syncdelay); BO_UNLOCK(bo); /* * 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, 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; { 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; struct bufobj *bo; VI_LOCK(vp); bo = &vp->v_bufobj; vp->v_mount->mnt_syncer = NULL; if (bo->bo_flag & BO_ONWORKLST) { mtx_lock(&sync_mtx); LIST_REMOVE(bo, bo_synclist); syncer_worklist_len--; sync_vnode_count--; mtx_unlock(&sync_mtx); bo->bo_flag &= ~BO_ONWORKLST; } VI_UNLOCK(vp); return (0); } /* * Check if vnode represents a disk device */ int vn_isdisk(vp, errp) struct vnode *vp; int *errp; { int error; error = 0; dev_lock(); if (vp->v_type != VCHR) error = ENOTBLK; else if (vp->v_rdev == NULL) error = ENXIO; else if (vp->v_rdev->si_devsw == NULL) error = ENXIO; else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK)) error = ENOTBLK; dev_unlock(); if (errp != NULL) *errp = error; return (error == 0); } /* * 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, SUSER_ALLOWJAIL)) { /* 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, SUSER_ALLOWJAIL)) cap_granted |= VEXEC; } else { if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && !cap_check(cred, NULL, CAP_DAC_EXECUTE, SUSER_ALLOWJAIL)) cap_granted |= VEXEC; } if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL)) cap_granted |= VREAD; if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL)) cap_granted |= (VWRITE | VAPPEND); if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && !cap_check(cred, NULL, CAP_FOWNER, SUSER_ALLOWJAIL)) 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); } } #ifdef DEBUG_VFS_LOCKS /* * 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) int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */ SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0, ""); int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, 0, ""); int vfs_badlock_print = 1; /* Print lock violations. */ SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, 0, ""); #ifdef KDB int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */ SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW, &vfs_badlock_backtrace, 0, ""); #endif static void vfs_badlock(const char *msg, const char *str, struct vnode *vp) { #ifdef KDB if (vfs_badlock_backtrace) kdb_backtrace(); #endif if (vfs_badlock_print) printf("%s: %p %s\n", str, (void *)vp, msg); if (vfs_badlock_ddb) kdb_enter("lock violation"); } 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_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_vop_locked(struct vnode *vp, const char *str) { if (vp && !IGNORE_LOCK(vp) && VOP_ISLOCKED(vp, NULL) == 0) 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); } #if 0 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); } #endif /* 0 */ #endif /* DEBUG_VFS_LOCKS */ void vop_rename_pre(void *ap) { struct vop_rename_args *a = ap; #ifdef DEBUG_VFS_LOCKS 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"); if (a->a_tvp != a->a_fvp) ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked"); /* Check the target. */ if (a->a_tvp) ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked"); ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked"); #endif if (a->a_tdvp != a->a_fdvp) vhold(a->a_fdvp); if (a->a_tvp != a->a_fvp) vhold(a->a_fvp); vhold(a->a_tdvp); if (a->a_tvp) vhold(a->a_tvp); } void vop_strategy_pre(void *ap) { #ifdef DEBUG_VFS_LOCKS struct vop_strategy_args *a; struct buf *bp; a = ap; 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_ddb) kdb_enter("lock violation"); } #endif } void vop_lookup_pre(void *ap) { #ifdef DEBUG_VFS_LOCKS struct vop_lookup_args *a; struct vnode *dvp; a = ap; dvp = a->a_dvp; ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); #endif } void vop_lookup_post(void *ap, int rc) { #ifdef DEBUG_VFS_LOCKS struct vop_lookup_args *a; struct vnode *dvp; struct vnode *vp; a = ap; dvp = a->a_dvp; vp = *(a->a_vpp); ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); if (!rc) ASSERT_VOP_LOCKED(vp, "VOP_LOOKUP (child)"); #endif } void vop_lock_pre(void *ap) { #ifdef DEBUG_VFS_LOCKS 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"); #endif } void vop_lock_post(void *ap, int rc) { #ifdef DEBUG_VFS_LOCKS struct vop_lock_args *a = ap; ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); if (rc == 0) ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); #endif } void vop_unlock_pre(void *ap) { #ifdef DEBUG_VFS_LOCKS 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"); #endif } void vop_unlock_post(void *ap, int rc) { #ifdef DEBUG_VFS_LOCKS struct vop_unlock_args *a = ap; if (a->a_flags & LK_INTERLOCK) ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); #endif } void vop_create_post(void *ap, int rc) { struct vop_create_args *a = ap; if (!rc) VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); } void vop_link_post(void *ap, int rc) { struct vop_link_args *a = ap; if (!rc) { VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK); VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE); } } void vop_mkdir_post(void *ap, int rc) { struct vop_mkdir_args *a = ap; if (!rc) VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); } void vop_mknod_post(void *ap, int rc) { struct vop_mknod_args *a = ap; if (!rc) VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); } void vop_remove_post(void *ap, int rc) { struct vop_remove_args *a = ap; if (!rc) { VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); } } void vop_rename_post(void *ap, int rc) { struct vop_rename_args *a = ap; if (!rc) { VFS_KNOTE_UNLOCKED(a->a_fdvp, NOTE_WRITE); VFS_KNOTE_UNLOCKED(a->a_tdvp, NOTE_WRITE); VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME); if (a->a_tvp) VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE); } if (a->a_tdvp != a->a_fdvp) vdrop(a->a_fdvp); if (a->a_tvp != a->a_fvp) vdrop(a->a_fvp); vdrop(a->a_tdvp); if (a->a_tvp) vdrop(a->a_tvp); } void vop_rmdir_post(void *ap, int rc) { struct vop_rmdir_args *a = ap; if (!rc) { VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK); VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE); } } void vop_setattr_post(void *ap, int rc) { struct vop_setattr_args *a = ap; if (!rc) VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); } void vop_symlink_post(void *ap, int rc) { struct vop_symlink_args *a = ap; if (!rc) VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE); } static struct knlist fs_knlist; static void vfs_event_init(void *arg) { knlist_init(&fs_knlist, NULL, NULL, NULL, NULL); } /* XXX - correct order? */ SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); void vfs_event_signal(fsid_t *fsid, u_int32_t event, intptr_t data __unused) { KNOTE_UNLOCKED(&fs_knlist, event); } static int filt_fsattach(struct knote *kn); static void filt_fsdetach(struct knote *kn); static int filt_fsevent(struct knote *kn, long hint); struct filterops fs_filtops = { 0, filt_fsattach, filt_fsdetach, filt_fsevent }; static int filt_fsattach(struct knote *kn) { kn->kn_flags |= EV_CLEAR; knlist_add(&fs_knlist, kn, 0); return (0); } static void filt_fsdetach(struct knote *kn) { knlist_remove(&fs_knlist, kn, 0); } static int filt_fsevent(struct knote *kn, long hint) { kn->kn_fflags |= hint; return (kn->kn_fflags != 0); } static int sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS) { struct vfsidctl vc; int error; struct mount *mp; error = SYSCTL_IN(req, &vc, sizeof(vc)); if (error) return (error); if (vc.vc_vers != VFS_CTL_VERS1) return (EINVAL); mp = vfs_getvfs(&vc.vc_fsid); if (mp == NULL) return (ENOENT); /* ensure that a specific sysctl goes to the right filesystem. */ if (strcmp(vc.vc_fstypename, "*") != 0 && strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) { return (EINVAL); } VCTLTOREQ(&vc, req); return (VFS_SYSCTL(mp, vc.vc_op, req)); } SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLFLAG_WR, NULL, 0, sysctl_vfs_ctl, "", "Sysctl by fsid"); /* * Function to initialize a va_filerev field sensibly. * XXX: Wouldn't a random number make a lot more sense ?? */ u_quad_t init_va_filerev(void) { struct bintime bt; getbinuptime(&bt); return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL)); } static int filt_vfsread(struct knote *kn, long hint); static int filt_vfswrite(struct knote *kn, long hint); static int filt_vfsvnode(struct knote *kn, long hint); static void filt_vfsdetach(struct knote *kn); static struct filterops vfsread_filtops = { 1, NULL, filt_vfsdetach, filt_vfsread }; static struct filterops vfswrite_filtops = { 1, NULL, filt_vfsdetach, filt_vfswrite }; static struct filterops vfsvnode_filtops = { 1, NULL, filt_vfsdetach, filt_vfsvnode }; static void vfs_knllock(void *arg) { struct vnode *vp = arg; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); } static void vfs_knlunlock(void *arg) { struct vnode *vp = arg; VOP_UNLOCK(vp, 0, curthread); } static int vfs_knllocked(void *arg) { struct vnode *vp = arg; return (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE); } int vfs_kqfilter(struct vop_kqfilter_args *ap) { struct vnode *vp = ap->a_vp; struct knote *kn = ap->a_kn; struct knlist *knl; switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &vfsread_filtops; break; case EVFILT_WRITE: kn->kn_fop = &vfswrite_filtops; break; case EVFILT_VNODE: kn->kn_fop = &vfsvnode_filtops; break; default: return (EINVAL); } kn->kn_hook = (caddr_t)vp; if (vp->v_pollinfo == NULL) v_addpollinfo(vp); if (vp->v_pollinfo == NULL) return (ENOMEM); knl = &vp->v_pollinfo->vpi_selinfo.si_note; knlist_add(knl, kn, 0); return (0); } /* * Detach knote from vnode */ static void filt_vfsdetach(struct knote *kn) { struct vnode *vp = (struct vnode *)kn->kn_hook; KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo")); knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0); } /*ARGSUSED*/ static int filt_vfsread(struct knote *kn, long hint) { struct vnode *vp = (struct vnode *)kn->kn_hook; struct vattr va; /* * filesystem is gone, so set the EOF flag and schedule * the knote for deletion. */ if (hint == NOTE_REVOKE) { kn->kn_flags |= (EV_EOF | EV_ONESHOT); return (1); } if (VOP_GETATTR(vp, &va, curthread->td_ucred, curthread)) return (0); kn->kn_data = va.va_size - kn->kn_fp->f_offset; return (kn->kn_data != 0); } /*ARGSUSED*/ static int filt_vfswrite(struct knote *kn, long hint) { /* * filesystem is gone, so set the EOF flag and schedule * the knote for deletion. */ if (hint == NOTE_REVOKE) kn->kn_flags |= (EV_EOF | EV_ONESHOT); kn->kn_data = 0; return (1); } static int filt_vfsvnode(struct knote *kn, long hint) { if (kn->kn_sfflags & hint) kn->kn_fflags |= hint; if (hint == NOTE_REVOKE) { kn->kn_flags |= EV_EOF; return (1); } return (kn->kn_fflags != 0); } int vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off) { int error; if (dp->d_reclen > ap->a_uio->uio_resid) return (ENAMETOOLONG); error = uiomove(dp, dp->d_reclen, ap->a_uio); if (error) { if (ap->a_ncookies != NULL) { if (ap->a_cookies != NULL) free(ap->a_cookies, M_TEMP); ap->a_cookies = NULL; *ap->a_ncookies = 0; } return (error); } if (ap->a_ncookies == NULL) return (0); *ap->a_cookies = realloc(*ap->a_cookies, (*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO); (*ap->a_cookies)[*ap->a_ncookies] = off; return (0); } /* * Mark for update the access time of the file if the filesystem * supports VA_MARK_ATIME. This functionality is used by execve * and mmap, so we want to avoid the synchronous I/O implied by * directly setting va_atime for the sake of efficiency. */ void vfs_mark_atime(struct vnode *vp, struct thread *td) { struct vattr atimeattr; if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) { VATTR_NULL(&atimeattr); atimeattr.va_vaflags |= VA_MARK_ATIME; (void)VOP_SETATTR(vp, &atimeattr, td->td_ucred, td); } }