diff options
Diffstat (limited to 'freebsd/sys/kern/vfs_subr.c')
| -rw-r--r-- | freebsd/sys/kern/vfs_subr.c | 5719 |
1 files changed, 5719 insertions, 0 deletions
diff --git a/freebsd/sys/kern/vfs_subr.c b/freebsd/sys/kern/vfs_subr.c new file mode 100644 index 00000000..f84caac0 --- /dev/null +++ b/freebsd/sys/kern/vfs_subr.c @@ -0,0 +1,5719 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * 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. 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_ddb.h" +#include "opt_watchdog.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bio.h> +#include <sys/buf.h> +#include <sys/capsicum.h> +#include <sys/condvar.h> +#include <sys/conf.h> +#include <sys/counter.h> +#include <sys/dirent.h> +#include <sys/event.h> +#include <sys/eventhandler.h> +#include <sys/extattr.h> +#include <sys/file.h> +#include <sys/fcntl.h> +#include <sys/jail.h> +#include <sys/kdb.h> +#include <sys/kernel.h> +#include <sys/kthread.h> +#include <sys/lockf.h> +#include <sys/malloc.h> +#include <sys/mount.h> +#include <sys/namei.h> +#include <sys/pctrie.h> +#include <sys/priv.h> +#include <sys/reboot.h> +#include <sys/refcount.h> +#include <sys/rwlock.h> +#include <sys/sched.h> +#include <sys/sleepqueue.h> +#include <sys/smp.h> +#include <sys/stat.h> +#include <sys/sysctl.h> +#include <sys/syslog.h> +#include <sys/vmmeter.h> +#include <sys/vnode.h> +#include <sys/watchdog.h> + +#include <machine/stdarg.h> + +#include <security/mac/mac_framework.h> + +#include <vm/vm.h> +#include <vm/vm_object.h> +#include <vm/vm_extern.h> +#include <vm/pmap.h> +#include <vm/vm_map.h> +#include <vm/vm_page.h> +#include <vm/vm_kern.h> +#include <vm/uma.h> + +#ifdef DDB +#include <ddb/ddb.h> +#endif + +static void delmntque(struct vnode *vp); +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 v_init_counters(struct vnode *); +static void v_incr_usecount(struct vnode *); +static void v_incr_usecount_locked(struct vnode *); +static void v_incr_devcount(struct vnode *); +static void v_decr_devcount(struct vnode *); +static void vgonel(struct vnode *); +static void vfs_knllock(void *arg); +static void vfs_knlunlock(void *arg); +static void vfs_knl_assert_locked(void *arg); +static void vfs_knl_assert_unlocked(void *arg); +static void vnlru_return_batches(struct vfsops *mnt_op); +static void destroy_vpollinfo(struct vpollinfo *vi); +static int v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, + daddr_t startlbn, daddr_t endlbn); + +/* + * These fences are intended for cases where some synchronization is + * needed between access of v_iflags and lockless vnode refcount (v_holdcnt + * and v_usecount) updates. Access to v_iflags is generally synchronized + * by the interlock, but we have some internal assertions that check vnode + * flags without acquiring the lock. Thus, these fences are INVARIANTS-only + * for now. + */ +#ifdef INVARIANTS +#define VNODE_REFCOUNT_FENCE_ACQ() atomic_thread_fence_acq() +#define VNODE_REFCOUNT_FENCE_REL() atomic_thread_fence_rel() +#else +#define VNODE_REFCOUNT_FENCE_ACQ() +#define VNODE_REFCOUNT_FENCE_REL() +#endif + +/* + * Number of vnodes in existence. Increased whenever getnewvnode() + * allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode. + */ +static unsigned long numvnodes; + +SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, + "Number of vnodes in existence"); + +static counter_u64_t vnodes_created; +SYSCTL_COUNTER_U64(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created, + "Number of vnodes created by getnewvnode"); + +static u_long mnt_free_list_batch = 128; +SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW, + &mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list"); + +/* + * 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, VNON +}; +int vttoif_tab[10] = { + 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, + S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT +}; + +/* + * List of vnodes that are ready for recycling. + */ +static TAILQ_HEAD(freelst, vnode) vnode_free_list; + +/* + * "Free" vnode target. Free vnodes are rarely completely free, but are + * just ones that are cheap to recycle. Usually they are for files which + * have been stat'd but not read; these usually have inode and namecache + * data attached to them. This target is the preferred minimum size of a + * sub-cache consisting mostly of such files. The system balances the size + * of this sub-cache with its complement to try to prevent either from + * thrashing while the other is relatively inactive. The targets express + * a preference for the best balance. + * + * "Above" this target there are 2 further targets (watermarks) related + * to recyling of free vnodes. In the best-operating case, the cache is + * exactly full, the free list has size between vlowat and vhiwat above the + * free target, and recycling from it and normal use maintains this state. + * Sometimes the free list is below vlowat or even empty, but this state + * is even better for immediate use provided the cache is not full. + * Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free + * ones) to reach one of these states. The watermarks are currently hard- + * coded as 4% and 9% of the available space higher. These and the default + * of 25% for wantfreevnodes are too large if the memory size is large. + * E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim + * whenever vnlru_proc() becomes active. + */ +static u_long wantfreevnodes; +SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, + &wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes"); +static u_long freevnodes; +SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, + &freevnodes, 0, "Number of \"free\" vnodes"); + +static counter_u64_t recycles_count; +SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, + "Number of vnodes recycled to meet vnode cache targets"); + +/* + * 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, + "Number of calls to reassignbuf"); + +static counter_u64_t free_owe_inact; +SYSCTL_COUNTER_U64(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, + "Number of times free vnodes kept on active list due to VFS " + "owing inactivation"); + +/* 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; + +static uma_zone_t buf_trie_zone; + +/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ +static uma_zone_t vnode_zone; +static uma_zone_t vnodepoll_zone; + +/* + * 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; +static struct cv sync_wakeup; + +#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, + "Time to delay syncing files (in seconds)"); +static int dirdelay = 29; /* time to delay syncing directories */ +SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, + "Time to delay syncing directories (in seconds)"); +static int metadelay = 28; /* time to delay syncing metadata */ +SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, + "Time to delay syncing metadata (in seconds)"); +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 times I/O speeded up (rush requests)"); + +/* + * 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; + +/* Target for maximum number of vnodes. */ +int desiredvnodes; +static int gapvnodes; /* gap between wanted and desired */ +static int vhiwat; /* enough extras after expansion */ +static int vlowat; /* minimal extras before expansion */ +static int vstir; /* nonzero to stir non-free vnodes */ +static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */ + +static int +sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS) +{ + int error, old_desiredvnodes; + + old_desiredvnodes = desiredvnodes; + if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0) + return (error); + if (old_desiredvnodes != desiredvnodes) { + wantfreevnodes = desiredvnodes / 4; + /* XXX locking seems to be incomplete. */ + vfs_hash_changesize(desiredvnodes); + cache_changesize(desiredvnodes); + } + return (0); +} + +SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes, + CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0, + sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes"); +SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, + &wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (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"); + +static int +sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) +{ + struct vnode *vp; + struct nameidata nd; + char *buf; + unsigned long ndflags; + int error; + + if (req->newptr == NULL) + return (EINVAL); + if (req->newlen >= PATH_MAX) + return (E2BIG); + + buf = malloc(PATH_MAX, M_TEMP, M_WAITOK); + error = SYSCTL_IN(req, buf, req->newlen); + if (error != 0) + goto out; + + buf[req->newlen] = '\0'; + + ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; + NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); + if ((error = namei(&nd)) != 0) + goto out; + vp = nd.ni_vp; + + if ((vp->v_iflag & VI_DOOMED) != 0) { + /* + * This vnode is being recycled. Return != 0 to let the caller + * know that the sysctl had no effect. Return EAGAIN because a + * subsequent call will likely succeed (since namei will create + * a new vnode if necessary) + */ + error = EAGAIN; + goto putvnode; + } + + counter_u64_add(recycles_count, 1); + vgone(vp); +putvnode: + NDFREE(&nd, 0); +out: + free(buf, M_TEMP); + return (error); +} + +static int +sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) +{ + struct thread *td = curthread; + struct vnode *vp; + struct file *fp; + int error; + int fd; + + if (req->newptr == NULL) + return (EBADF); + + error = sysctl_handle_int(oidp, &fd, 0, req); + if (error != 0) + return (error); + error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); + if (error != 0) + return (error); + vp = fp->f_vnode; + + error = vn_lock(vp, LK_EXCLUSIVE); + if (error != 0) + goto drop; + + counter_u64_add(recycles_count, 1); + vgone(vp); + VOP_UNLOCK(vp, 0); +drop: + fdrop(fp, td); + return (error); +} + +SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, + CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, + sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); +SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, + CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, + sysctl_ftry_reclaim_vnode, "I", + "Try to reclaim a vnode by its file descriptor"); + +/* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ +static int vnsz2log; + +/* + * Support for the bufobj clean & dirty pctrie. + */ +static void * +buf_trie_alloc(struct pctrie *ptree) +{ + + return uma_zalloc(buf_trie_zone, M_NOWAIT); +} + +static void +buf_trie_free(struct pctrie *ptree, void *node) +{ + + uma_zfree(buf_trie_zone, node); +} +PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free); + +/* + * Initialize the vnode management data structures. + * + * Reevaluate the following cap on the number of vnodes after the physical + * memory size exceeds 512GB. In the limit, as the physical memory size + * grows, the ratio of the memory size in KB to vnodes approaches 64:1. + */ +#ifndef MAXVNODES_MAX +#define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */ +#endif + +/* + * Initialize a vnode as it first enters the zone. + */ +static int +vnode_init(void *mem, int size, int flags) +{ + struct vnode *vp; + + vp = mem; + bzero(vp, size); + /* + * 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, "vnode", VLKTIMEOUT, + LK_NOSHARE | LK_IS_VNODE); + /* + * Initialize bufobj. + */ + bufobj_init(&vp->v_bufobj, vp); + /* + * Initialize namecache. + */ + LIST_INIT(&vp->v_cache_src); + TAILQ_INIT(&vp->v_cache_dst); + /* + * Initialize rangelocks. + */ + rangelock_init(&vp->v_rl); + return (0); +} + +/* + * Free a vnode when it is cleared from the zone. + */ +static void +vnode_fini(void *mem, int size) +{ + struct vnode *vp; + struct bufobj *bo; + + vp = mem; + rangelock_destroy(&vp->v_rl); + lockdestroy(vp->v_vnlock); + mtx_destroy(&vp->v_interlock); + bo = &vp->v_bufobj; + rw_destroy(BO_LOCKPTR(bo)); +} + +/* + * Provide the size of NFS nclnode and NFS fh for calculation of the + * vnode memory consumption. The size is specified directly to + * eliminate dependency on NFS-private header. + * + * Other filesystems may use bigger or smaller (like UFS and ZFS) + * private inode data, but the NFS-based estimation is ample enough. + * Still, we care about differences in the size between 64- and 32-bit + * platforms. + * + * Namecache structure size is heuristically + * sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1. + */ +#ifdef _LP64 +#define NFS_NCLNODE_SZ (528 + 64) +#define NC_SZ 148 +#else +#define NFS_NCLNODE_SZ (360 + 32) +#define NC_SZ 92 +#endif + +static void +vntblinit(void *dummy __unused) +{ + u_int i; + int physvnodes, virtvnodes; + + /* + * Desiredvnodes is a function of the physical memory size and the + * kernel's heap size. Generally speaking, it scales with the + * physical memory size. The ratio of desiredvnodes to the physical + * memory size is 1:16 until desiredvnodes exceeds 98,304. + * Thereafter, the + * marginal ratio of desiredvnodes to the physical memory size is + * 1:64. However, desiredvnodes is limited by the kernel's heap + * size. The memory required by desiredvnodes vnodes and vm objects + * must not exceed 1/10th of the kernel's heap size. + */ + physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 + + 3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64; + virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) + + sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ)); + desiredvnodes = min(physvnodes, virtvnodes); + 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, + vnode_init, vnode_fini, UMA_ALIGN_PTR, 0); + vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), + NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); + /* + * Preallocate enough nodes to support one-per buf so that + * we can not fail an insert. reassignbuf() callers can not + * tolerate the insertion failure. + */ + buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(), + NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, + UMA_ZONE_NOFREE | UMA_ZONE_VM); + uma_prealloc(buf_trie_zone, nbuf); + + vnodes_created = counter_u64_alloc(M_WAITOK); + recycles_count = counter_u64_alloc(M_WAITOK); + free_owe_inact = counter_u64_alloc(M_WAITOK); + + /* + * 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); + cv_init(&sync_wakeup, "syncer"); + for (i = 1; i <= sizeof(struct vnode); i <<= 1) + vnsz2log++; + vnsz2log--; +} +SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL); + + +/* + * Mark a mount point as busy. Used to synchronize access and to delay + * unmounting. Eventually, mountlist_mtx is not released on failure. + * + * vfs_busy() is a custom lock, it can block the caller. + * vfs_busy() only sleeps if the unmount is active on the mount point. + * For a mountpoint mp, vfs_busy-enforced lock is before lock of any + * vnode belonging to mp. + * + * Lookup uses vfs_busy() to traverse mount points. + * root fs var fs + * / vnode lock A / vnode lock (/var) D + * /var vnode lock B /log vnode lock(/var/log) E + * vfs_busy lock C vfs_busy lock F + * + * Within each file system, the lock order is C->A->B and F->D->E. + * + * When traversing across mounts, the system follows that lock order: + * + * C->A->B + * | + * +->F->D->E + * + * The lookup() process for namei("/var") illustrates the process: + * VOP_LOOKUP() obtains B while A is held + * vfs_busy() obtains a shared lock on F while A and B are held + * vput() releases lock on B + * vput() releases lock on A + * VFS_ROOT() obtains lock on D while shared lock on F is held + * vfs_unbusy() releases shared lock on F + * vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A. + * Attempt to lock A (instead of vp_crossmp) while D is held would + * violate the global order, causing deadlocks. + * + * dounmount() locks B while F is drained. + */ +int +vfs_busy(struct mount *mp, int flags) +{ + + MPASS((flags & ~MBF_MASK) == 0); + CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags); + + MNT_ILOCK(mp); + MNT_REF(mp); + /* + * If mount point is currently being unmounted, sleep until the + * mount point fate is decided. If thread doing the unmounting fails, + * it will clear MNTK_UNMOUNT flag before waking us up, indicating + * that this mount point has survived the unmount attempt and vfs_busy + * should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE + * flag in addition to MNTK_UNMOUNT, indicating that mount point is + * about to be really destroyed. vfs_busy needs to release its + * reference on the mount point in this case and return with ENOENT, + * telling the caller that mount mount it tried to busy is no longer + * valid. + */ + while (mp->mnt_kern_flag & MNTK_UNMOUNT) { + if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) { + MNT_REL(mp); + MNT_IUNLOCK(mp); + CTR1(KTR_VFS, "%s: failed busying before sleeping", + __func__); + return (ENOENT); + } + if (flags & MBF_MNTLSTLOCK) + mtx_unlock(&mountlist_mtx); + mp->mnt_kern_flag |= MNTK_MWAIT; + msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0); + if (flags & MBF_MNTLSTLOCK) + mtx_lock(&mountlist_mtx); + MNT_ILOCK(mp); + } + if (flags & MBF_MNTLSTLOCK) + mtx_unlock(&mountlist_mtx); + mp->mnt_lockref++; + MNT_IUNLOCK(mp); + return (0); +} + +/* + * Free a busy filesystem. + */ +void +vfs_unbusy(struct mount *mp) +{ + + CTR2(KTR_VFS, "%s: mp %p", __func__, mp); + MNT_ILOCK(mp); + MNT_REL(mp); + KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref")); + mp->mnt_lockref--; + if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) { + MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT); + CTR1(KTR_VFS, "%s: waking up waiters", __func__); + mp->mnt_kern_flag &= ~MNTK_DRAINING; + wakeup(&mp->mnt_lockref); + } + MNT_IUNLOCK(mp); +} + +/* + * Lookup a mount point by filesystem identifier. + */ +struct mount * +vfs_getvfs(fsid_t *fsid) +{ + struct mount *mp; + + CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); + 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]) { + vfs_ref(mp); + mtx_unlock(&mountlist_mtx); + return (mp); + } + } + mtx_unlock(&mountlist_mtx); + CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); + return ((struct mount *) 0); +} + +/* + * Lookup a mount point by filesystem identifier, busying it before + * returning. + * + * To avoid congestion on mountlist_mtx, implement simple direct-mapped + * cache for popular filesystem identifiers. The cache is lockess, using + * the fact that struct mount's are never freed. In worst case we may + * get pointer to unmounted or even different filesystem, so we have to + * check what we got, and go slow way if so. + */ +struct mount * +vfs_busyfs(fsid_t *fsid) +{ +#define FSID_CACHE_SIZE 256 + typedef struct mount * volatile vmp_t; + static vmp_t cache[FSID_CACHE_SIZE]; + struct mount *mp; + int error; + uint32_t hash; + + CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid); + hash = fsid->val[0] ^ fsid->val[1]; + hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1); + mp = cache[hash]; + if (mp == NULL || + mp->mnt_stat.f_fsid.val[0] != fsid->val[0] || + mp->mnt_stat.f_fsid.val[1] != fsid->val[1]) + goto slow; + if (vfs_busy(mp, 0) != 0) { + cache[hash] = NULL; + goto slow; + } + if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && + mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) + return (mp); + else + vfs_unbusy(mp); + +slow: + 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]) { + error = vfs_busy(mp, MBF_MNTLSTLOCK); + if (error) { + cache[hash] = NULL; + mtx_unlock(&mountlist_mtx); + return (NULL); + } + cache[hash] = mp; + return (mp); + } + } + CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid); + mtx_unlock(&mountlist_mtx); + return ((struct mount *) 0); +} + +/* + * Check if a user can access privileged mount options. + */ +int +vfs_suser(struct mount *mp, struct thread *td) +{ + int error; + + if (jailed(td->td_ucred)) { + /* + * If the jail of the calling thread lacks permission for + * this type of file system, deny immediately. + */ + if (!prison_allow(td->td_ucred, mp->mnt_vfc->vfc_prison_flag)) + return (EPERM); + + /* + * If the file system was mounted outside the jail of the + * calling thread, deny immediately. + */ + if (prison_check(td->td_ucred, mp->mnt_cred) != 0) + return (EPERM); + } + + /* + * If file system supports delegated administration, we don't check + * for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified + * by the file system itself. + * If this is not the user that did original mount, we check for + * the PRIV_VFS_MOUNT_OWNER privilege. + */ + if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) && + mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { + if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 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(struct mount *mp) +{ + static uint16_t mntid_base; + struct mount *nmp; + fsid_t tfsid; + int mtype; + + CTR2(KTR_VFS, "%s: mp %p", __func__, mp); + 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 ((nmp = vfs_getvfs(&tfsid)) == NULL) + break; + vfs_rel(nmp); + } + 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_USEC; +SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, + ×tamp_precision, 0, "File timestamp precision (0: seconds, " + "1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to us, " + "3+: sec + ns (max. precision))"); + +/* + * Get a current timestamp. + */ +void +vfs_timestamp(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(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 <count> 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 + * desirable 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. + * + * @param mp Try to reclaim vnodes from this mountpoint + * @param reclaim_nc_src Only reclaim directories with outgoing namecache + * entries if this argument is strue + * @param trigger Only reclaim vnodes with fewer than this many resident + * pages. + * @return The number of vnodes that were reclaimed. + */ +static int +vlrureclaim(struct mount *mp, bool reclaim_nc_src, int trigger) +{ + struct vnode *vp; + int count, done, target; + + done = 0; + vn_start_write(NULL, &mp, V_WAIT); + MNT_ILOCK(mp); + count = mp->mnt_nvnodelistsize; + target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1); + target = target / 10 + 1; + while (count != 0 && done < target) { + vp = TAILQ_FIRST(&mp->mnt_nvnodelist); + while (vp != NULL && vp->v_type == VMARKER) + vp = TAILQ_NEXT(vp, v_nmntvnodes); + if (vp == NULL) + break; + /* + * XXX LRU is completely broken for non-free vnodes. First + * by calling here in mountpoint order, then by moving + * unselected vnodes to the end here, and most grossly by + * removing the vlruvp() function that was supposed to + * maintain the order. (This function was born broken + * since syncer problems prevented it doing anything.) The + * order is closer to LRC (C = Created). + * + * LRU reclaiming of vnodes seems to have last worked in + * FreeBSD-3 where LRU wasn't mentioned under any spelling. + * Then there was no hold count, and inactive vnodes were + * simply put on the free list in LRU order. The separate + * lists also break LRU. We prefer to reclaim from the + * free list for technical reasons. This tends to thrash + * the free list to keep very unrecently used held vnodes. + * The problem is mitigated by keeping the free list large. + */ + 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. + * Also skip free vnodes. We are trying to make space + * to expand the free list, not reduce it. + */ + if (vp->v_usecount || + (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || + ((vp->v_iflag & VI_FREE) != 0) || + (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)) { + 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 || + (!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) || + (vp->v_iflag & VI_FREE) != 0 || + (vp->v_object != NULL && + vp->v_object->resident_page_count > trigger)) { + VOP_UNLOCK(vp, LK_INTERLOCK); + vdrop(vp); + goto next_iter_mntunlocked; + } + KASSERT((vp->v_iflag & VI_DOOMED) == 0, + ("VI_DOOMED unexpectedly detected in vlrureclaim()")); + counter_u64_add(recycles_count, 1); + vgonel(vp); + VOP_UNLOCK(vp, 0); + vdropl(vp); + done++; +next_iter_mntunlocked: + if (!should_yield()) + goto relock_mnt; + goto yield; +next_iter: + if (!should_yield()) + continue; + MNT_IUNLOCK(mp); +yield: + kern_yield(PRI_USER); +relock_mnt: + MNT_ILOCK(mp); + } + MNT_IUNLOCK(mp); + vn_finished_write(mp); + return done; +} + +static int max_vnlru_free = 10000; /* limit on vnode free requests per call */ +SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free, + 0, + "limit on vnode free requests per call to the vnlru_free routine"); + +/* + * Attempt to reduce the free list by the requested amount. + */ +static void +vnlru_free_locked(int count, struct vfsops *mnt_op) +{ + struct vnode *vp; + struct mount *mp; + bool tried_batches; + + tried_batches = false; + mtx_assert(&vnode_free_list_mtx, MA_OWNED); + if (count > max_vnlru_free) + count = max_vnlru_free; + 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 == NULL) { + if (tried_batches) + break; + mtx_unlock(&vnode_free_list_mtx); + vnlru_return_batches(mnt_op); + tried_batches = true; + mtx_lock(&vnode_free_list_mtx); + continue; + } + + VNASSERT(vp->v_op != NULL, vp, + ("vnlru_free: vnode already reclaimed.")); + KASSERT((vp->v_iflag & VI_FREE) != 0, + ("Removing vnode not on freelist")); + KASSERT((vp->v_iflag & VI_ACTIVE) == 0, + ("Mangling active vnode")); + TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); + + /* + * Don't recycle if our vnode is from different type + * of mount point. Note that mp is type-safe, the + * check does not reach unmapped address even if + * vnode is reclaimed. + * Don't recycle if we can't get the interlock without + * blocking. + */ + if ((mnt_op != NULL && (mp = vp->v_mount) != NULL && + mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) { + TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist); + continue; + } + VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0, + vp, ("vp inconsistent on freelist")); + + /* + * The clear of VI_FREE prevents activation of the + * vnode. There is no sense in putting the vnode on + * the mount point active list, only to remove it + * later during recycling. Inline the relevant part + * of vholdl(), to avoid triggering assertions or + * activating. + */ + freevnodes--; + vp->v_iflag &= ~VI_FREE; + VNODE_REFCOUNT_FENCE_REL(); + refcount_acquire(&vp->v_holdcnt); + + 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); + } +} + +void +vnlru_free(int count, struct vfsops *mnt_op) +{ + + mtx_lock(&vnode_free_list_mtx); + vnlru_free_locked(count, mnt_op); + mtx_unlock(&vnode_free_list_mtx); +} + + +/* XXX some names and initialization are bad for limits and watermarks. */ +static int +vspace(void) +{ + int space; + + gapvnodes = imax(desiredvnodes - wantfreevnodes, 100); + vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */ + vlowat = vhiwat / 2; + if (numvnodes > desiredvnodes) + return (0); + space = desiredvnodes - numvnodes; + if (freevnodes > wantfreevnodes) + space += freevnodes - wantfreevnodes; + return (space); +} + +static void +vnlru_return_batch_locked(struct mount *mp) +{ + struct vnode *vp; + + mtx_assert(&mp->mnt_listmtx, MA_OWNED); + + if (mp->mnt_tmpfreevnodelistsize == 0) + return; + + TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) { + VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp, + ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist")); + vp->v_mflag &= ~VMP_TMPMNTFREELIST; + } + mtx_lock(&vnode_free_list_mtx); + TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist); + freevnodes += mp->mnt_tmpfreevnodelistsize; + mtx_unlock(&vnode_free_list_mtx); + mp->mnt_tmpfreevnodelistsize = 0; +} + +static void +vnlru_return_batch(struct mount *mp) +{ + + mtx_lock(&mp->mnt_listmtx); + vnlru_return_batch_locked(mp); + mtx_unlock(&mp->mnt_listmtx); +} + +static void +vnlru_return_batches(struct vfsops *mnt_op) +{ + struct mount *mp, *nmp; + bool need_unbusy; + + mtx_lock(&mountlist_mtx); + for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { + need_unbusy = false; + if (mnt_op != NULL && mp->mnt_op != mnt_op) + goto next; + if (mp->mnt_tmpfreevnodelistsize == 0) + goto next; + if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) { + vnlru_return_batch(mp); + need_unbusy = true; + mtx_lock(&mountlist_mtx); + } +next: + nmp = TAILQ_NEXT(mp, mnt_list); + if (need_unbusy) + vfs_unbusy(mp); + } + mtx_unlock(&mountlist_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; + unsigned long onumvnodes; + int done, force, trigger, usevnodes, vsp; + bool reclaim_nc_src; + + EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc, + SHUTDOWN_PRI_FIRST); + + force = 0; + for (;;) { + kproc_suspend_check(vnlruproc); + mtx_lock(&vnode_free_list_mtx); + /* + * If numvnodes is too large (due to desiredvnodes being + * adjusted using its sysctl, or emergency growth), first + * try to reduce it by discarding from the free list. + */ + if (numvnodes > desiredvnodes) + vnlru_free_locked(numvnodes - desiredvnodes, NULL); + /* + * Sleep if the vnode cache is in a good state. This is + * when it is not over-full and has space for about a 4% + * or 9% expansion (by growing its size or inexcessively + * reducing its free list). Otherwise, try to reclaim + * space for a 10% expansion. + */ + if (vstir && force == 0) { + force = 1; + vstir = 0; + } + vsp = vspace(); + if (vsp >= vlowat && force == 0) { + 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; + onumvnodes = numvnodes; + /* + * Calculate parameters for recycling. These are the same + * throughout the loop to give some semblance of fairness. + * The trigger point is to avoid recycling vnodes with lots + * of resident pages. We aren't trying to free memory; we + * are trying to recycle or at least free vnodes. + */ + if (numvnodes <= desiredvnodes) + usevnodes = numvnodes - freevnodes; + else + usevnodes = numvnodes; + if (usevnodes <= 0) + usevnodes = 1; + /* + * The trigger value is is chosen to give a conservatively + * large value to ensure that it alone doesn't prevent + * making progress. The value can easily be so large that + * it is effectively infinite in some congested and + * misconfigured cases, and this is necessary. Normally + * it is about 8 to 100 (pages), which is quite large. + */ + trigger = vm_cnt.v_page_count * 2 / usevnodes; + if (force < 2) + trigger = vsmalltrigger; + reclaim_nc_src = force >= 3; + mtx_lock(&mountlist_mtx); + for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { + if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) { + nmp = TAILQ_NEXT(mp, mnt_list); + continue; + } + done += vlrureclaim(mp, reclaim_nc_src, trigger); + mtx_lock(&mountlist_mtx); + nmp = TAILQ_NEXT(mp, mnt_list); + vfs_unbusy(mp); + } + mtx_unlock(&mountlist_mtx); + if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes) + uma_reclaim(); + if (done == 0) { + if (force == 0 || force == 1) { + force = 2; + continue; + } + if (force == 2) { + force = 3; + continue; + } + force = 0; + vnlru_nowhere++; + tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); + } else + kern_yield(PRI_USER); + /* + * After becoming active to expand above low water, keep + * active until above high water. + */ + vsp = vspace(); + force = vsp < vhiwat; + } +} + +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. + */ + +/* + * 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 mount *vnmp; + + CTR2(KTR_VFS, "%s: vp %p", __func__, 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) != 0) { + CTR2(KTR_VFS, + "%s: impossible to recycle, vp %p lock is already held", + __func__, vp); + return (EWOULDBLOCK); + } + /* + * Don't recycle if its filesystem is being suspended. + */ + if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) { + VOP_UNLOCK(vp, 0); + CTR2(KTR_VFS, + "%s: impossible to recycle, cannot start the write for %p", + __func__, vp); + 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); + vn_finished_write(vnmp); + CTR2(KTR_VFS, + "%s: impossible to recycle, %p is already referenced", + __func__, vp); + return (EBUSY); + } + if ((vp->v_iflag & VI_DOOMED) == 0) { + counter_u64_add(recycles_count, 1); + vgonel(vp); + } + VOP_UNLOCK(vp, LK_INTERLOCK); + vn_finished_write(vnmp); + return (0); +} + +static void +vcheckspace(void) +{ + int vsp; + + vsp = vspace(); + if (vsp < vlowat && vnlruproc_sig == 0) { + vnlruproc_sig = 1; + wakeup(vnlruproc); + } +} + +/* + * Wait if necessary for space for a new vnode. + */ +static int +getnewvnode_wait(int suspended) +{ + + mtx_assert(&vnode_free_list_mtx, MA_OWNED); + if (numvnodes >= desiredvnodes) { + if (suspended) { + /* + * The file system is being suspended. We cannot + * risk a deadlock here, so allow allocation of + * another vnode even if this would give too many. + */ + return (0); + } + if (vnlruproc_sig == 0) { + vnlruproc_sig = 1; /* avoid unnecessary wakeups */ + wakeup(vnlruproc); + } + msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS, + "vlruwk", hz); + } + /* Post-adjust like the pre-adjust in getnewvnode(). */ + if (numvnodes + 1 > desiredvnodes && freevnodes > 1) + vnlru_free_locked(1, NULL); + return (numvnodes >= desiredvnodes ? ENFILE : 0); +} + +/* + * This hack is fragile, and probably not needed any more now that the + * watermark handling works. + */ +void +getnewvnode_reserve(u_int count) +{ + struct thread *td; + + /* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */ + /* XXX no longer so quick, but this part is not racy. */ + mtx_lock(&vnode_free_list_mtx); + if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes) + vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes, + freevnodes - wantfreevnodes), NULL); + mtx_unlock(&vnode_free_list_mtx); + + td = curthread; + /* First try to be quick and racy. */ + if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) { + td->td_vp_reserv += count; + vcheckspace(); /* XXX no longer so quick, but more racy */ + return; + } else + atomic_subtract_long(&numvnodes, count); + + mtx_lock(&vnode_free_list_mtx); + while (count > 0) { + if (getnewvnode_wait(0) == 0) { + count--; + td->td_vp_reserv++; + atomic_add_long(&numvnodes, 1); + } + } + vcheckspace(); + mtx_unlock(&vnode_free_list_mtx); +} + +/* + * This hack is fragile, especially if desiredvnodes or wantvnodes are + * misconfgured or changed significantly. Reducing desiredvnodes below + * the reserved amount should cause bizarre behaviour like reducing it + * below the number of active vnodes -- the system will try to reduce + * numvnodes to match, but should fail, so the subtraction below should + * not overflow. + */ +void +getnewvnode_drop_reserve(void) +{ + struct thread *td; + + td = curthread; + atomic_subtract_long(&numvnodes, td->td_vp_reserv); + td->td_vp_reserv = 0; +} + +/* + * Return the next vnode from the free list. + */ +int +getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops, + struct vnode **vpp) +{ + struct vnode *vp; + struct thread *td; + struct lock_object *lo; + static int cyclecount; + int error __unused; + + CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag); + vp = NULL; + td = curthread; + if (td->td_vp_reserv > 0) { + td->td_vp_reserv -= 1; + goto alloc; + } + mtx_lock(&vnode_free_list_mtx); + if (numvnodes < desiredvnodes) + cyclecount = 0; + else if (cyclecount++ >= freevnodes) { + cyclecount = 0; + vstir = 1; + } + /* + * Grow the vnode cache if it will not be above its target max + * after growing. Otherwise, if the free list is nonempty, try + * to reclaim 1 item from it before growing the cache (possibly + * above its target max if the reclamation failed or is delayed). + * Otherwise, wait for some space. In all cases, schedule + * vnlru_proc() if we are getting short of space. The watermarks + * should be chosen so that we never wait or even reclaim from + * the free list to below its target minimum. + */ + if (numvnodes + 1 <= desiredvnodes) + ; + else if (freevnodes > 0) + vnlru_free_locked(1, NULL); + else { + error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag & + MNTK_SUSPEND)); +#if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */ + if (error != 0) { + mtx_unlock(&vnode_free_list_mtx); + return (error); + } +#endif + } + vcheckspace(); + atomic_add_long(&numvnodes, 1); + mtx_unlock(&vnode_free_list_mtx); +alloc: + counter_u64_add(vnodes_created, 1); + vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK); + /* + * Locks are given the generic name "vnode" when created. + * Follow the historic practice of using the filesystem + * name when they allocated, e.g., "zfs", "ufs", "nfs, etc. + * + * Locks live in a witness group keyed on their name. Thus, + * when a lock is renamed, it must also move from the witness + * group of its old name to the witness group of its new name. + * + * The change only needs to be made when the vnode moves + * from one filesystem type to another. We ensure that each + * filesystem use a single static name pointer for its tag so + * that we can compare pointers rather than doing a strcmp(). + */ + lo = &vp->v_vnlock->lock_object; + if (lo->lo_name != tag) { + lo->lo_name = tag; + WITNESS_DESTROY(lo); + WITNESS_INIT(lo, tag); + } + /* + * By default, don't allow shared locks unless filesystems opt-in. + */ + vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE; + /* + * Finalize various vnode identity bits. + */ + KASSERT(vp->v_object == NULL, ("stale v_object %p", vp)); + KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp)); + KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp)); + vp->v_type = VNON; + vp->v_tag = tag; + vp->v_op = vops; + v_init_counters(vp); + vp->v_bufobj.bo_ops = &buf_ops_bio; +#ifdef DIAGNOSTIC + if (mp == NULL && vops != &dead_vnodeops) + printf("NULL mp in getnewvnode(9), tag %s\n", tag); +#endif +#ifdef MAC + mac_vnode_init(vp); + if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) + mac_vnode_associate_singlelabel(mp, vp); +#endif + if (mp != NULL) { + vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize; + if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0) + vp->v_vflag |= VV_NOKNOTE; + } + + /* + * For the filesystems which do not use vfs_hash_insert(), + * still initialize v_hash to have vfs_hash_index() useful. + * E.g., nullfs uses vfs_hash_index() on the lower vnode for + * its own hashing. + */ + vp->v_hash = (uintptr_t)vp >> vnsz2log; + + *vpp = vp; + return (0); +} + +/* + * Delete from old mount point vnode list, if on one. + */ +static void +delmntque(struct vnode *vp) +{ + struct mount *mp; + int active; + + mp = vp->v_mount; + if (mp == NULL) + return; + MNT_ILOCK(mp); + VI_LOCK(vp); + KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize, + ("Active vnode list size %d > Vnode list size %d", + mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize)); + active = vp->v_iflag & VI_ACTIVE; + vp->v_iflag &= ~VI_ACTIVE; + if (active) { + mtx_lock(&mp->mnt_listmtx); + TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist); + mp->mnt_activevnodelistsize--; + mtx_unlock(&mp->mnt_listmtx); + } + vp->v_mount = NULL; + VI_UNLOCK(vp); + VNASSERT(mp->mnt_nvnodelistsize > 0, vp, + ("bad mount point vnode list size")); + TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + mp->mnt_nvnodelistsize--; + MNT_REL(mp); + MNT_IUNLOCK(mp); +} + +static void +insmntque_stddtr(struct vnode *vp, void *dtr_arg) +{ + + vp->v_data = NULL; + vp->v_op = &dead_vnodeops; + vgone(vp); + vput(vp); +} + +/* + * Insert into list of vnodes for the new mount point, if available. + */ +int +insmntque1(struct vnode *vp, struct mount *mp, + void (*dtr)(struct vnode *, void *), void *dtr_arg) +{ + + KASSERT(vp->v_mount == NULL, + ("insmntque: vnode already on per mount vnode list")); + VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)")); + ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp"); + + /* + * We acquire the vnode interlock early to ensure that the + * vnode cannot be recycled by another process releasing a + * holdcnt on it before we get it on both the vnode list + * and the active vnode list. The mount mutex protects only + * manipulation of the vnode list and the vnode freelist + * mutex protects only manipulation of the active vnode list. + * Hence the need to hold the vnode interlock throughout. + */ + MNT_ILOCK(mp); + VI_LOCK(vp); + if (((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 && + ((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 || + mp->mnt_nvnodelistsize == 0)) && + (vp->v_vflag & VV_FORCEINSMQ) == 0) { + VI_UNLOCK(vp); + MNT_IUNLOCK(mp); + if (dtr != NULL) + dtr(vp, dtr_arg); + return (EBUSY); + } + vp->v_mount = mp; + MNT_REF(mp); + TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + VNASSERT(mp->mnt_nvnodelistsize >= 0, vp, + ("neg mount point vnode list size")); + mp->mnt_nvnodelistsize++; + KASSERT((vp->v_iflag & VI_ACTIVE) == 0, + ("Activating already active vnode")); + vp->v_iflag |= VI_ACTIVE; + mtx_lock(&mp->mnt_listmtx); + TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); + mp->mnt_activevnodelistsize++; + mtx_unlock(&mp->mnt_listmtx); + VI_UNLOCK(vp); + MNT_IUNLOCK(mp); + return (0); +} + +int +insmntque(struct vnode *vp, struct mount *mp) +{ + + return (insmntque1(vp, mp, insmntque_stddtr, NULL)); +} + +/* + * Flush out and invalidate all buffers associated with a bufobj + * Called with the underlying object locked. + */ +int +bufobj_invalbuf(struct bufobj *bo, int flags, 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)) != 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 && !(flags & V_CLEANONLY)) + 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); + if ((flags & V_VMIO) == 0) { + BO_UNLOCK(bo); + if (bo->bo_object != NULL) { + VM_OBJECT_WLOCK(bo->bo_object); + vm_object_pip_wait(bo->bo_object, "bovlbx"); + VM_OBJECT_WUNLOCK(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 && + (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) { + VM_OBJECT_WLOCK(bo->bo_object); + vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ? + OBJPR_CLEANONLY : 0); + VM_OBJECT_WUNLOCK(bo->bo_object); + } + +#ifdef INVARIANTS + BO_LOCK(bo); + if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO | + V_ALLOWCLEAN)) == 0 && (bo->bo_dirty.bv_cnt > 0 || + bo->bo_clean.bv_cnt > 0)) + panic("vinvalbuf: flush failed"); + if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 && + bo->bo_dirty.bv_cnt > 0) + panic("vinvalbuf: flush dirty 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, int slpflag, int slptimeo) +{ + + CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); + ASSERT_VOP_LOCKED(vp, "vinvalbuf"); + if (vp->v_object != NULL && vp->v_object->handle != vp) + return (0); + return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo)); +} + +/* + * Flush out buffers on the specified list. + * + */ +static int +flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag, + int slptimeo) +{ + struct buf *bp, *nbp; + int retval, error; + daddr_t lblkno; + b_xflags_t xflags; + + ASSERT_BO_WLOCKED(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; + } + if (nbp != NULL) { + lblkno = nbp->b_lblkno; + xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN); + } + retval = EAGAIN; + error = BUF_TIMELOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(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)); + /* + * 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_RELBUF); + bp->b_flags &= ~B_ASYNC; + brelse(bp); + BO_LOCK(bo); + if (nbp == NULL) + break; + nbp = gbincore(bo, lblkno); + if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) + != xflags) + break; /* nbp invalid */ + } + return (retval); +} + +int +bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn) +{ + struct buf *bp; + int error; + daddr_t lblkno; + + ASSERT_BO_LOCKED(bo); + + for (lblkno = startn;;) { +again: + bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno); + if (bp == NULL || bp->b_lblkno >= endn || + bp->b_lblkno < startn) + break; + error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL | + LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0); + if (error != 0) { + BO_RLOCK(bo); + if (error == ENOLCK) + goto again; + return (error); + } + KASSERT(bp->b_bufobj == bo, + ("bp %p wrong b_bufobj %p should be %p", + bp, bp->b_bufobj, bo)); + lblkno = bp->b_lblkno + 1; + if ((bp->b_flags & B_MANAGED) == 0) + bremfree(bp); + bp->b_flags |= B_RELBUF; + /* + * In the VMIO case, use the B_NOREUSE flag to hint that the + * pages backing each buffer in the range are unlikely to be + * reused. Dirty buffers will have the hint applied once + * they've been written. + */ + if ((bp->b_flags & B_VMIO) != 0) + bp->b_flags |= B_NOREUSE; + brelse(bp); + BO_RLOCK(bo); + } + return (0); +} + +/* + * Truncate a file's buffer and pages to a specified length. This + * is in lieu of the old vinvalbuf mechanism, which performed unneeded + * sync activity. + */ +int +vtruncbuf(struct vnode *vp, off_t length, int blksize) +{ + struct buf *bp, *nbp; + struct bufobj *bo; + daddr_t startlbn; + + CTR4(KTR_VFS, "%s: vp %p with block %d:%ju", __func__, + vp, blksize, (uintmax_t)length); + + /* + * Round up to the *next* lbn. + */ + startlbn = howmany(length, blksize); + + ASSERT_VOP_LOCKED(vp, "vtruncbuf"); + + bo = &vp->v_bufobj; +restart_unlocked: + BO_LOCK(bo); + + while (v_inval_buf_range_locked(vp, bo, startlbn, INT64_MAX) == EAGAIN) + ; + + 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, + BO_LOCKPTR(bo)) == ENOLCK) + goto restart_unlocked; + + VNASSERT((bp->b_flags & B_DELWRI), vp, + ("buf(%p) on dirty queue without DELWRI", bp)); + + bremfree(bp); + bawrite(bp); + BO_LOCK(bo); + goto restartsync; + } + } + + bufobj_wwait(bo, 0, 0); + BO_UNLOCK(bo); + vnode_pager_setsize(vp, length); + + return (0); +} + +/* + * Invalidate the cached pages of a file's buffer within the range of block + * numbers [startlbn, endlbn). + */ +void +v_inval_buf_range(struct vnode *vp, daddr_t startlbn, daddr_t endlbn, + int blksize) +{ + struct bufobj *bo; + off_t start, end; + + ASSERT_VOP_LOCKED(vp, "v_inval_buf_range"); + + start = blksize * startlbn; + end = blksize * endlbn; + + bo = &vp->v_bufobj; + BO_LOCK(bo); + MPASS(blksize == bo->bo_bsize); + + while (v_inval_buf_range_locked(vp, bo, startlbn, endlbn) == EAGAIN) + ; + + BO_UNLOCK(bo); + vn_pages_remove(vp, OFF_TO_IDX(start), OFF_TO_IDX(end + PAGE_SIZE - 1)); +} + +static int +v_inval_buf_range_locked(struct vnode *vp, struct bufobj *bo, + daddr_t startlbn, daddr_t endlbn) +{ + struct buf *bp, *nbp; + bool anyfreed; + + ASSERT_VOP_LOCKED(vp, "v_inval_buf_range_locked"); + ASSERT_BO_LOCKED(bo); + + do { + anyfreed = false; + TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) { + if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) + continue; + if (BUF_LOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, + BO_LOCKPTR(bo)) == ENOLCK) { + BO_LOCK(bo); + return (EAGAIN); + } + + bremfree(bp); + bp->b_flags |= B_INVAL | B_RELBUF; + bp->b_flags &= ~B_ASYNC; + brelse(bp); + anyfreed = true; + + BO_LOCK(bo); + if (nbp != NULL && + (((nbp->b_xflags & BX_VNCLEAN) == 0) || + nbp->b_vp != vp || + (nbp->b_flags & B_DELWRI) != 0)) + return (EAGAIN); + } + + TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) { + if (bp->b_lblkno < startlbn || bp->b_lblkno >= endlbn) + continue; + if (BUF_LOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, + BO_LOCKPTR(bo)) == ENOLCK) { + BO_LOCK(bo); + return (EAGAIN); + } + bremfree(bp); + bp->b_flags |= B_INVAL | B_RELBUF; + bp->b_flags &= ~B_ASYNC; + brelse(bp); + anyfreed = true; + + BO_LOCK(bo); + if (nbp != NULL && + (((nbp->b_xflags & BX_VNDIRTY) == 0) || + (nbp->b_vp != vp) || + (nbp->b_flags & B_DELWRI) == 0)) + return (EAGAIN); + } + } while (anyfreed); + return (0); +} + +static void +buf_vlist_remove(struct buf *bp) +{ + struct bufv *bv; + + KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); + ASSERT_BO_WLOCKED(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; + BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno); + 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. + * + * 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 bufv *bv; + struct buf *n; + int error; + + ASSERT_BO_WLOCKED(bo); + KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0, + ("dead bo %p", 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; + + /* + * Keep the list ordered. Optimize empty list insertion. Assume + * we tend to grow at the tail so lookup_le should usually be cheaper + * than _ge. + */ + if (bv->bv_cnt == 0 || + bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno) + TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs); + else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL) + TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs); + else + TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs); + error = BUF_PCTRIE_INSERT(&bv->bv_root, bp); + if (error) + panic("buf_vlist_add: Preallocated nodes insufficient."); + bv->bv_cnt++; +} + +/* + * Look up a buffer using the buffer tries. + */ +struct buf * +gbincore(struct bufobj *bo, daddr_t lblkno) +{ + struct buf *bp; + + ASSERT_BO_LOCKED(bo); + bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno); + if (bp != NULL) + return (bp); + return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno); +} + +/* + * Associate a buffer with a vnode. + */ +void +bgetvp(struct vnode *vp, struct buf *bp) +{ + struct bufobj *bo; + + bo = &vp->v_bufobj; + ASSERT_BO_WLOCKED(bo); + 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)); + + vhold(vp); + bp->b_vp = vp; + bp->b_bufobj = bo; + /* + * Insert onto list for new vnode. + */ + buf_vlist_add(bp, bo, 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; + BO_UNLOCK(bo); + vdrop(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_WLOCKED(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 synclist *slp, struct bufobj **bo, struct thread *td) +{ + struct vnode *vp; + struct mount *mp; + + *bo = LIST_FIRST(slp); + if (*bo == NULL) + return (0); + vp = bo2vnode(*bo); + if (VOP_ISLOCKED(vp) != 0 || 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 (*bo == LIST_FIRST(slp)); + } + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); + (void) VOP_FSYNC(vp, MNT_LAZY, td); + VOP_UNLOCK(vp, 0); + vn_finished_write(mp); + BO_LOCK(*bo); + 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); + } + BO_UNLOCK(*bo); + vdrop(vp); + mtx_lock(&sync_mtx); + return (0); +} + +static int first_printf = 1; + +/* + * System filesystem synchronizer daemon. + */ +static void +sched_sync(void) +{ + struct synclist *next, *slp; + struct bufobj *bo; + long starttime; + struct thread *td = curthread; + int last_work_seen; + int net_worklist_len; + int syncer_final_iter; + int error; + + last_work_seen = 0; + syncer_final_iter = 0; + 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); + + mtx_lock(&sync_mtx); + for (;;) { + if (syncer_state == SYNCER_FINAL_DELAY && + syncer_final_iter == 0) { + mtx_unlock(&sync_mtx); + kproc_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 (!LIST_EMPTY(slp)) { + error = sync_vnode(slp, &bo, td); + if (error == 1) { + LIST_REMOVE(bo, bo_synclist); + LIST_INSERT_HEAD(next, bo, bo_synclist); + continue; + } + + if (first_printf == 0) { + /* + * Drop the sync mutex, because some watchdog + * drivers need to sleep while patting + */ + mtx_unlock(&sync_mtx); + wdog_kern_pat(WD_LASTVAL); + mtx_lock(&sync_mtx); + } + + } + if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0) + syncer_final_iter--; + /* + * The variable rushjob allows the kernel to speed up the + * processing of the filesystem syncer process. A rushjob + * value of N tells the filesystem syncer to process the next + * N seconds worth of work on its queue ASAP. Currently rushjob + * is used by the soft update code to speed up the filesystem + * syncer process when the incore state is getting so far + * ahead of the disk that the kernel memory pool is being + * threatened with exhaustion. + */ + if (rushjob > 0) { + rushjob -= 1; + continue; + } + /* + * Just sleep for a short period of 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 || + time_uptime == starttime) { + thread_lock(td); + sched_prio(td, PPAUSE); + thread_unlock(td); + } + if (syncer_state != SYNCER_RUNNING) + cv_timedwait(&sync_wakeup, &sync_mtx, + hz / SYNCER_SHUTDOWN_SPEEDUP); + else if (time_uptime == starttime) + cv_timedwait(&sync_wakeup, &sync_mtx, hz); + } +} + +/* + * 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(void) +{ + int ret = 0; + + mtx_lock(&sync_mtx); + if (rushjob < syncdelay / 2) { + rushjob += 1; + stat_rush_requests += 1; + ret = 1; + } + mtx_unlock(&sync_mtx); + cv_broadcast(&sync_wakeup); + 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) +{ + + if (howto & RB_NOSYNC) + return; + mtx_lock(&sync_mtx); + syncer_state = SYNCER_SHUTTING_DOWN; + rushjob = 0; + mtx_unlock(&sync_mtx); + cv_broadcast(&sync_wakeup); + kproc_shutdown(arg, howto); +} + +void +syncer_suspend(void) +{ + + syncer_shutdown(updateproc, 0); +} + +void +syncer_resume(void) +{ + + mtx_lock(&sync_mtx); + first_printf = 1; + syncer_state = SYNCER_RUNNING; + mtx_unlock(&sync_mtx); + cv_broadcast(&sync_wakeup); + kproc_resume(updateproc); +} + +/* + * 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. + */ + BO_LOCK(bo); + 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 + BO_UNLOCK(bo); +} + +static void +v_init_counters(struct vnode *vp) +{ + + VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0, + vp, ("%s called for an initialized vnode", __FUNCTION__)); + ASSERT_VI_UNLOCKED(vp, __FUNCTION__); + + refcount_init(&vp->v_holdcnt, 1); + refcount_init(&vp->v_usecount, 1); +} + +static void +v_incr_usecount_locked(struct vnode *vp) +{ + + ASSERT_VI_LOCKED(vp, __func__); + if ((vp->v_iflag & VI_OWEINACT) != 0) { + VNASSERT(vp->v_usecount == 0, vp, + ("vnode with usecount and VI_OWEINACT set")); + vp->v_iflag &= ~VI_OWEINACT; + } + refcount_acquire(&vp->v_usecount); + v_incr_devcount(vp); +} + +/* + * Increment the use count on the vnode, taking care to reference + * the driver's usecount if this is a chardev. + */ +static void +v_incr_usecount(struct vnode *vp) +{ + + ASSERT_VI_UNLOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + + if (vp->v_type != VCHR && + refcount_acquire_if_not_zero(&vp->v_usecount)) { + VNODE_REFCOUNT_FENCE_ACQ(); + VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp, + ("vnode with usecount and VI_OWEINACT set")); + } else { + VI_LOCK(vp); + v_incr_usecount_locked(vp); + VI_UNLOCK(vp); + } +} + +/* + * Increment si_usecount of the associated device, if any. + */ +static void +v_incr_devcount(struct vnode *vp) +{ + + ASSERT_VI_LOCKED(vp, __FUNCTION__); + if (vp->v_type == VCHR && vp->v_rdev != NULL) { + dev_lock(); + vp->v_rdev->si_usecount++; + dev_unlock(); + } +} + +/* + * Decrement si_usecount of the associated device, if any. + */ +static void +v_decr_devcount(struct vnode *vp) +{ + + ASSERT_VI_LOCKED(vp, __FUNCTION__); + 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. VI_DOOMED is set if the vnode + * is being destroyed. Only callers who specify LK_RETRY will + * see doomed vnodes. If inactive processing was delayed in + * vput try to do it here. + * + * Notes on lockless counter manipulation: + * _vhold, vputx and other routines make various decisions based + * on either holdcnt or usecount being 0. As long as either counter + * is not transitioning 0->1 nor 1->0, the manipulation can be done + * with atomic operations. Otherwise the interlock is taken covering + * both the atomic and additional actions. + */ +int +vget(struct vnode *vp, int flags, struct thread *td) +{ + int error, oweinact; + + VNASSERT((flags & LK_TYPE_MASK) != 0, vp, + ("vget: invalid lock operation")); + + if ((flags & LK_INTERLOCK) != 0) + ASSERT_VI_LOCKED(vp, __func__); + else + ASSERT_VI_UNLOCKED(vp, __func__); + if ((flags & LK_VNHELD) != 0) + VNASSERT((vp->v_holdcnt > 0), vp, + ("vget: LK_VNHELD passed but vnode not held")); + + CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags); + + if ((flags & LK_VNHELD) == 0) + _vhold(vp, (flags & LK_INTERLOCK) != 0); + + if ((error = vn_lock(vp, flags)) != 0) { + vdrop(vp); + CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__, + vp); + return (error); + } + if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0) + panic("vget: vn_lock failed to return ENOENT\n"); + /* + * We don't guarantee that any particular close will + * trigger inactive processing so just make a best effort + * here at preventing a reference to a removed file. If + * we don't succeed no harm is done. + * + * Upgrade our holdcnt to a usecount. + */ + if (vp->v_type == VCHR || + !refcount_acquire_if_not_zero(&vp->v_usecount)) { + VI_LOCK(vp); + if ((vp->v_iflag & VI_OWEINACT) == 0) { + oweinact = 0; + } else { + oweinact = 1; + vp->v_iflag &= ~VI_OWEINACT; + VNODE_REFCOUNT_FENCE_REL(); + } + refcount_acquire(&vp->v_usecount); + v_incr_devcount(vp); + if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE && + (flags & LK_NOWAIT) == 0) + vinactive(vp, td); + VI_UNLOCK(vp); + } + return (0); +} + +/* + * Increase the reference (use) and hold count of a vnode. + * This will also remove the vnode from the free list if it is presently free. + */ +void +vref(struct vnode *vp) +{ + + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + _vhold(vp, false); + v_incr_usecount(vp); +} + +void +vrefl(struct vnode *vp) +{ + + ASSERT_VI_LOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + _vhold(vp, true); + v_incr_usecount_locked(vp); +} + +void +vrefact(struct vnode *vp) +{ + + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + if (__predict_false(vp->v_type == VCHR)) { + VNASSERT(vp->v_holdcnt > 0 && vp->v_usecount > 0, vp, + ("%s: wrong ref counts", __func__)); + vref(vp); + return; + } +#ifdef INVARIANTS + int old = atomic_fetchadd_int(&vp->v_holdcnt, 1); + VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__)); + old = atomic_fetchadd_int(&vp->v_usecount, 1); + VNASSERT(old > 0, vp, ("%s: wrong use count", __func__)); +#else + refcount_acquire(&vp->v_holdcnt); + refcount_acquire(&vp->v_usecount); +#endif +} + +/* + * Return reference count of a vnode. + * + * The results of this call are only guaranteed when some mechanism 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) +{ + + return (vp->v_usecount); +} + +#define VPUTX_VRELE 1 +#define VPUTX_VPUT 2 +#define VPUTX_VUNREF 3 + +/* + * Decrement the use and hold counts for a vnode. + * + * See an explanation near vget() as to why atomic operation is safe. + */ +static void +vputx(struct vnode *vp, int func) +{ + int error; + + KASSERT(vp != NULL, ("vputx: null vp")); + if (func == VPUTX_VUNREF) + ASSERT_VOP_LOCKED(vp, "vunref"); + else if (func == VPUTX_VPUT) + ASSERT_VOP_LOCKED(vp, "vput"); + else + KASSERT(func == VPUTX_VRELE, ("vputx: wrong func")); + ASSERT_VI_UNLOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + + if (vp->v_type != VCHR && + refcount_release_if_not_last(&vp->v_usecount)) { + if (func == VPUTX_VPUT) + VOP_UNLOCK(vp, 0); + vdrop(vp); + return; + } + + VI_LOCK(vp); + + /* + * 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. + */ + if (!refcount_release(&vp->v_usecount) || + (vp->v_iflag & VI_DOINGINACT)) { + if (func == VPUTX_VPUT) + VOP_UNLOCK(vp, 0); + v_decr_devcount(vp); + vdropl(vp); + return; + } + + v_decr_devcount(vp); + + error = 0; + + if (vp->v_usecount != 0) { + vn_printf(vp, "vputx: usecount not zero for vnode "); + panic("vputx: usecount not zero"); + } + + CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp); + + /* + * We must call VOP_INACTIVE with the node locked. Mark + * as VI_DOINGINACT to avoid recursion. + */ + vp->v_iflag |= VI_OWEINACT; + switch (func) { + case VPUTX_VRELE: + error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK); + VI_LOCK(vp); + break; + case VPUTX_VPUT: + if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { + error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK | + LK_NOWAIT); + VI_LOCK(vp); + } + break; + case VPUTX_VUNREF: + if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) { + error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK); + VI_LOCK(vp); + } + break; + } + VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp, + ("vnode with usecount and VI_OWEINACT set")); + if (error == 0) { + if (vp->v_iflag & VI_OWEINACT) + vinactive(vp, curthread); + if (func != VPUTX_VUNREF) + VOP_UNLOCK(vp, 0); + } + vdropl(vp); +} + +/* + * Vnode put/release. + * If count drops to zero, call inactive routine and return to freelist. + */ +void +vrele(struct vnode *vp) +{ + + vputx(vp, VPUTX_VRELE); +} + +/* + * 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() acquires the lock internally.) + */ +void +vput(struct vnode *vp) +{ + + vputx(vp, VPUTX_VPUT); +} + +/* + * Release an exclusively locked vnode. Do not unlock the vnode lock. + */ +void +vunref(struct vnode *vp) +{ + + vputx(vp, VPUTX_VUNREF); +} + +/* + * Increase the hold count and activate if this is the first reference. + */ +void +_vhold(struct vnode *vp, bool locked) +{ + struct mount *mp; + + if (locked) + ASSERT_VI_LOCKED(vp, __func__); + else + ASSERT_VI_UNLOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + if (!locked) { + if (refcount_acquire_if_not_zero(&vp->v_holdcnt)) { + VNODE_REFCOUNT_FENCE_ACQ(); + VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, + ("_vhold: vnode with holdcnt is free")); + return; + } + VI_LOCK(vp); + } + if ((vp->v_iflag & VI_FREE) == 0) { + refcount_acquire(&vp->v_holdcnt); + if (!locked) + VI_UNLOCK(vp); + return; + } + VNASSERT(vp->v_holdcnt == 0, vp, + ("%s: wrong hold count", __func__)); + VNASSERT(vp->v_op != NULL, vp, + ("%s: vnode already reclaimed.", __func__)); + /* + * Remove a vnode from the free list, mark it as in use, + * and put it on the active list. + */ + VNASSERT(vp->v_mount != NULL, vp, + ("_vhold: vnode not on per mount vnode list")); + mp = vp->v_mount; + mtx_lock(&mp->mnt_listmtx); + if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) { + TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist); + mp->mnt_tmpfreevnodelistsize--; + vp->v_mflag &= ~VMP_TMPMNTFREELIST; + } else { + mtx_lock(&vnode_free_list_mtx); + TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist); + freevnodes--; + mtx_unlock(&vnode_free_list_mtx); + } + KASSERT((vp->v_iflag & VI_ACTIVE) == 0, + ("Activating already active vnode")); + vp->v_iflag &= ~VI_FREE; + vp->v_iflag |= VI_ACTIVE; + TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist); + mp->mnt_activevnodelistsize++; + mtx_unlock(&mp->mnt_listmtx); + refcount_acquire(&vp->v_holdcnt); + if (!locked) + VI_UNLOCK(vp); +} + +/* + * Drop the hold count of the vnode. If this is the last reference to + * the vnode we place it on the free list unless it has been vgone'd + * (marked VI_DOOMED) in which case we will free it. + * + * Because the vnode vm object keeps a hold reference on the vnode if + * there is at least one resident non-cached page, the vnode cannot + * leave the active list without the page cleanup done. + */ +void +_vdrop(struct vnode *vp, bool locked) +{ + struct bufobj *bo; + struct mount *mp; + int active; + + if (locked) + ASSERT_VI_LOCKED(vp, __func__); + else + ASSERT_VI_UNLOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + if ((int)vp->v_holdcnt <= 0) + panic("vdrop: holdcnt %d", vp->v_holdcnt); + if (!locked) { + if (refcount_release_if_not_last(&vp->v_holdcnt)) + return; + VI_LOCK(vp); + } + if (refcount_release(&vp->v_holdcnt) == 0) { + VI_UNLOCK(vp); + return; + } + if ((vp->v_iflag & VI_DOOMED) == 0) { + /* + * Mark a vnode as free: remove it from its active list + * and put it up for recycling on the freelist. + */ + VNASSERT(vp->v_op != NULL, vp, + ("vdropl: vnode already reclaimed.")); + VNASSERT((vp->v_iflag & VI_FREE) == 0, vp, + ("vnode already free")); + VNASSERT(vp->v_holdcnt == 0, vp, + ("vdropl: freeing when we shouldn't")); + active = vp->v_iflag & VI_ACTIVE; + if ((vp->v_iflag & VI_OWEINACT) == 0) { + vp->v_iflag &= ~VI_ACTIVE; + mp = vp->v_mount; + if (mp != NULL) { + mtx_lock(&mp->mnt_listmtx); + if (active) { + TAILQ_REMOVE(&mp->mnt_activevnodelist, + vp, v_actfreelist); + mp->mnt_activevnodelistsize--; + } + TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, + vp, v_actfreelist); + mp->mnt_tmpfreevnodelistsize++; + vp->v_iflag |= VI_FREE; + vp->v_mflag |= VMP_TMPMNTFREELIST; + VI_UNLOCK(vp); + if (mp->mnt_tmpfreevnodelistsize >= + mnt_free_list_batch) + vnlru_return_batch_locked(mp); + mtx_unlock(&mp->mnt_listmtx); + } else { + VNASSERT(active == 0, vp, + ("vdropl: active vnode not on per mount " + "vnode list")); + mtx_lock(&vnode_free_list_mtx); + TAILQ_INSERT_TAIL(&vnode_free_list, vp, + v_actfreelist); + freevnodes++; + vp->v_iflag |= VI_FREE; + VI_UNLOCK(vp); + mtx_unlock(&vnode_free_list_mtx); + } + } else { + VI_UNLOCK(vp); + counter_u64_add(free_owe_inact, 1); + } + return; + } + /* + * The vnode has been marked for destruction, so free it. + * + * The vnode will be returned to the zone where it will + * normally remain until it is needed for another vnode. We + * need to cleanup (or verify that the cleanup has already + * been done) any residual data left from its current use + * so as not to contaminate the freshly allocated vnode. + */ + CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp); + atomic_subtract_long(&numvnodes, 1); + 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(pctrie_is_empty(&bo->bo_clean.bv_root), vp, + ("clean blk trie not empty")); + VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0")); + VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp, + ("dirty blk trie not empty")); + VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst")); + VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src")); + VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for ..")); + VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp, + ("Dangling rangelock waiters")); + VI_UNLOCK(vp); +#ifdef MAC + mac_vnode_destroy(vp); +#endif + if (vp->v_pollinfo != NULL) { + destroy_vpollinfo(vp->v_pollinfo); + vp->v_pollinfo = NULL; + } +#ifdef INVARIANTS + /* XXX Elsewhere we detect an already freed vnode via NULL v_op. */ + vp->v_op = NULL; +#endif + vp->v_mountedhere = NULL; + vp->v_unpcb = NULL; + vp->v_rdev = NULL; + vp->v_fifoinfo = NULL; + vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; + vp->v_iflag = 0; + vp->v_vflag = 0; + bo->bo_flag = 0; + uma_zfree(vnode_zone, 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. + */ +void +vinactive(struct vnode *vp, struct thread *td) +{ + struct vm_object *obj; + + ASSERT_VOP_ELOCKED(vp, "vinactive"); + ASSERT_VI_LOCKED(vp, "vinactive"); + VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp, + ("vinactive: recursed on VI_DOINGINACT")); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + vp->v_iflag |= VI_DOINGINACT; + vp->v_iflag &= ~VI_OWEINACT; + VI_UNLOCK(vp); + /* + * Before moving off the active list, we must be sure that any + * modified pages are converted into the vnode's dirty + * buffers, since these will no longer be checked once the + * vnode is on the inactive list. + * + * The write-out of the dirty pages is asynchronous. At the + * point that VOP_INACTIVE() is called, there could still be + * pending I/O and dirty pages in the object. + */ + if ((obj = vp->v_object) != NULL && (vp->v_vflag & VV_NOSYNC) == 0 && + (obj->flags & OBJ_MIGHTBEDIRTY) != 0) { + VM_OBJECT_WLOCK(obj); + vm_object_page_clean(obj, 0, 0, 0); + VM_OBJECT_WUNLOCK(obj); + } + 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, "Print out busy vnodes"); +#endif + +int +vflush(struct mount *mp, int rootrefs, int flags, struct thread *td) +{ + struct vnode *vp, *mvp, *rootvp = NULL; + struct vattr vattr; + int busy = 0, error; + + CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp, + rootrefs, flags); + 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)) != 0) { + CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d", + __func__, error); + return (error); + } + vput(rootvp); + } +loop: + MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { + vholdl(vp); + error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE); + if (error) { + vdrop(vp); + MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); + goto loop; + } + /* + * Skip over a vnodes marked VV_SYSTEM. + */ + if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { + VOP_UNLOCK(vp, 0); + vdrop(vp); + 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) { + if (vp->v_object != NULL) { + VM_OBJECT_WLOCK(vp->v_object); + vm_object_page_clean(vp->v_object, 0, 0, 0); + VM_OBJECT_WUNLOCK(vp->v_object); + } + error = VOP_FSYNC(vp, MNT_WAIT, td); + if (error != 0) { + VOP_UNLOCK(vp, 0); + vdrop(vp); + MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); + return (error); + } + error = VOP_GETATTR(vp, &vattr, td->td_ucred); + 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); + vdropl(vp); + 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)) { + vgonel(vp); + } else { + busy++; +#ifdef DIAGNOSTIC + if (busyprt) + vn_printf(vp, "vflush: busy vnode "); +#endif + } + VOP_UNLOCK(vp, 0); + vdropl(vp); + } + 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); + vgone(rootvp); + VOP_UNLOCK(rootvp, 0); + busy = 0; + } else + VI_UNLOCK(rootvp); + } + if (busy) { + CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__, + 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) +{ + int recycled; + + VI_LOCK(vp); + recycled = vrecyclel(vp); + VI_UNLOCK(vp); + return (recycled); +} + +/* + * vrecycle, with the vp interlock held. + */ +int +vrecyclel(struct vnode *vp) +{ + int recycled; + + ASSERT_VOP_ELOCKED(vp, __func__); + ASSERT_VI_LOCKED(vp, __func__); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + recycled = 0; + if (vp->v_usecount == 0) { + recycled = 1; + vgonel(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); +} + +static void +notify_lowervp_vfs_dummy(struct mount *mp __unused, + struct vnode *lowervp __unused) +{ +} + +/* + * Notify upper mounts about reclaimed or unlinked vnode. + */ +void +vfs_notify_upper(struct vnode *vp, int event) +{ + static struct vfsops vgonel_vfsops = { + .vfs_reclaim_lowervp = notify_lowervp_vfs_dummy, + .vfs_unlink_lowervp = notify_lowervp_vfs_dummy, + }; + struct mount *mp, *ump, *mmp; + + mp = vp->v_mount; + if (mp == NULL) + return; + + MNT_ILOCK(mp); + if (TAILQ_EMPTY(&mp->mnt_uppers)) + goto unlock; + MNT_IUNLOCK(mp); + mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO); + mmp->mnt_op = &vgonel_vfsops; + mmp->mnt_kern_flag |= MNTK_MARKER; + MNT_ILOCK(mp); + mp->mnt_kern_flag |= MNTK_VGONE_UPPER; + for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) { + if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) { + ump = TAILQ_NEXT(ump, mnt_upper_link); + continue; + } + TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link); + MNT_IUNLOCK(mp); + switch (event) { + case VFS_NOTIFY_UPPER_RECLAIM: + VFS_RECLAIM_LOWERVP(ump, vp); + break; + case VFS_NOTIFY_UPPER_UNLINK: + VFS_UNLINK_LOWERVP(ump, vp); + break; + default: + KASSERT(0, ("invalid event %d", event)); + break; + } + MNT_ILOCK(mp); + ump = TAILQ_NEXT(mmp, mnt_upper_link); + TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link); + } + free(mmp, M_TEMP); + mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER; + if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) { + mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER; + wakeup(&mp->mnt_uppers); + } +unlock: + MNT_IUNLOCK(mp); +} + +/* + * vgone, with the vp interlock held. + */ +static void +vgonel(struct vnode *vp) +{ + struct thread *td; + int oweinact; + int active; + struct mount *mp; + + ASSERT_VOP_ELOCKED(vp, "vgonel"); + ASSERT_VI_LOCKED(vp, "vgonel"); + VNASSERT(vp->v_holdcnt, vp, + ("vgonel: vp %p has no reference.", vp)); + CTR2(KTR_VFS, "%s: vp %p", __func__, vp); + 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); + vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM); + + /* + * 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); + } + if (vp->v_type == VSOCK) + vfs_unp_reclaim(vp); + + /* + * Clean out any buffers associated with the vnode. + * If the flush fails, just toss the buffers. + */ + mp = NULL; + if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd)) + (void) vn_start_secondary_write(vp, &mp, V_WAIT); + if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) { + while (vinvalbuf(vp, 0, 0, 0) != 0) + ; + } + + BO_LOCK(&vp->v_bufobj); + KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) && + vp->v_bufobj.bo_dirty.bv_cnt == 0 && + TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) && + vp->v_bufobj.bo_clean.bv_cnt == 0, + ("vp %p bufobj not invalidated", vp)); + + /* + * For VMIO bufobj, BO_DEAD is set in vm_object_terminate() + * after the object's page queue is flushed. + */ + if (vp->v_bufobj.bo_object == NULL) + vp->v_bufobj.bo_flag |= BO_DEAD; + BO_UNLOCK(&vp->v_bufobj); + + /* + * Reclaim the vnode. + */ + if (VOP_RECLAIM(vp, td)) + panic("vgone: cannot reclaim"); + if (mp != NULL) + vn_finished_secondary_write(mp); + VNASSERT(vp->v_object == NULL, vp, + ("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag)); + /* + * Clear the advisory locks and wake up waiting threads. + */ + (void)VOP_ADVLOCKPURGE(vp); + vp->v_lockf = NULL; + /* + * 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(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(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", + "VMARKER"}; + +void +vn_printf(struct vnode *vp, const char *fmt, ...) +{ + va_list ap; + char buf[256], buf2[16]; + u_long flags; + + 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", + vp->v_usecount, vp->v_writecount, vp->v_holdcnt); + switch (vp->v_type) { + case VDIR: + printf(" mountedhere %p\n", vp->v_mountedhere); + break; + case VCHR: + printf(" rdev %p\n", vp->v_rdev); + break; + case VSOCK: + printf(" socket %p\n", vp->v_unpcb); + break; + case VFIFO: + printf(" fifoinfo %p\n", vp->v_fifoinfo); + break; + default: + printf("\n"); + break; + } + buf[0] = '\0'; + buf[1] = '\0'; + if (vp->v_vflag & VV_ROOT) + strlcat(buf, "|VV_ROOT", sizeof(buf)); + if (vp->v_vflag & VV_ISTTY) + strlcat(buf, "|VV_ISTTY", sizeof(buf)); + if (vp->v_vflag & VV_NOSYNC) + strlcat(buf, "|VV_NOSYNC", sizeof(buf)); + if (vp->v_vflag & VV_ETERNALDEV) + strlcat(buf, "|VV_ETERNALDEV", sizeof(buf)); + if (vp->v_vflag & VV_CACHEDLABEL) + strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf)); + if (vp->v_vflag & VV_COPYONWRITE) + strlcat(buf, "|VV_COPYONWRITE", sizeof(buf)); + if (vp->v_vflag & VV_SYSTEM) + strlcat(buf, "|VV_SYSTEM", sizeof(buf)); + if (vp->v_vflag & VV_PROCDEP) + strlcat(buf, "|VV_PROCDEP", sizeof(buf)); + if (vp->v_vflag & VV_NOKNOTE) + strlcat(buf, "|VV_NOKNOTE", sizeof(buf)); + if (vp->v_vflag & VV_DELETED) + strlcat(buf, "|VV_DELETED", sizeof(buf)); + if (vp->v_vflag & VV_MD) + strlcat(buf, "|VV_MD", sizeof(buf)); + if (vp->v_vflag & VV_FORCEINSMQ) + strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf)); + flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV | + VV_CACHEDLABEL | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP | + VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ); + if (flags != 0) { + snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags); + strlcat(buf, buf2, sizeof(buf)); + } + if (vp->v_iflag & VI_MOUNT) + strlcat(buf, "|VI_MOUNT", sizeof(buf)); + if (vp->v_iflag & VI_DOOMED) + strlcat(buf, "|VI_DOOMED", sizeof(buf)); + if (vp->v_iflag & VI_FREE) + strlcat(buf, "|VI_FREE", sizeof(buf)); + if (vp->v_iflag & VI_ACTIVE) + strlcat(buf, "|VI_ACTIVE", sizeof(buf)); + if (vp->v_iflag & VI_DOINGINACT) + strlcat(buf, "|VI_DOINGINACT", sizeof(buf)); + if (vp->v_iflag & VI_OWEINACT) + strlcat(buf, "|VI_OWEINACT", sizeof(buf)); + if (vp->v_iflag & VI_TEXT_REF) + strlcat(buf, "|VI_TEXT_REF", sizeof(buf)); + flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE | + VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT | VI_TEXT_REF); + if (flags != 0) { + snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags); + strlcat(buf, buf2, sizeof(buf)); + } + 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 " + "cleanbuf %d dirtybuf %d\n", + vp->v_object, vp->v_object->ref_count, + vp->v_object->resident_page_count, + vp->v_bufobj.bo_clean.bv_cnt, + vp->v_bufobj.bo_dirty.bv_cnt); + printf(" "); + lockmgr_printinfo(vp->v_vnlock); + if (vp->v_data != NULL) + VOP_PRINT(vp); +} + +#ifdef DDB +/* + * List all of the locked vnodes in the system. + * Called when debugging the kernel. + */ +DB_SHOW_COMMAND(lockedvnods, lockedvnodes) +{ + struct mount *mp; + 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. + */ + db_printf("Locked vnodes\n"); + TAILQ_FOREACH(mp, &mountlist, mnt_list) { + TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { + if (vp->v_type != VMARKER && VOP_ISLOCKED(vp)) + vn_printf(vp, "vnode "); + } + } +} + +/* + * Show details about the given vnode. + */ +DB_SHOW_COMMAND(vnode, db_show_vnode) +{ + struct vnode *vp; + + if (!have_addr) + return; + vp = (struct vnode *)addr; + vn_printf(vp, "vnode "); +} + +/* + * Show details about the given mount point. + */ +DB_SHOW_COMMAND(mount, db_show_mount) +{ + struct mount *mp; + struct vfsopt *opt; + struct statfs *sp; + struct vnode *vp; + char buf[512]; + uint64_t mflags; + u_int flags; + + if (!have_addr) { + /* No address given, print short info about all mount points. */ + TAILQ_FOREACH(mp, &mountlist, mnt_list) { + db_printf("%p %s on %s (%s)\n", mp, + mp->mnt_stat.f_mntfromname, + mp->mnt_stat.f_mntonname, + mp->mnt_stat.f_fstypename); + if (db_pager_quit) + break; + } + db_printf("\nMore info: show mount <addr>\n"); + return; + } + + mp = (struct mount *)addr; + db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname, + mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename); + + buf[0] = '\0'; + mflags = mp->mnt_flag; +#define MNT_FLAG(flag) do { \ + if (mflags & (flag)) { \ + if (buf[0] != '\0') \ + strlcat(buf, ", ", sizeof(buf)); \ + strlcat(buf, (#flag) + 4, sizeof(buf)); \ + mflags &= ~(flag); \ + } \ +} while (0) + MNT_FLAG(MNT_RDONLY); + MNT_FLAG(MNT_SYNCHRONOUS); + MNT_FLAG(MNT_NOEXEC); + MNT_FLAG(MNT_NOSUID); + MNT_FLAG(MNT_NFS4ACLS); + MNT_FLAG(MNT_UNION); + MNT_FLAG(MNT_ASYNC); + MNT_FLAG(MNT_SUIDDIR); + MNT_FLAG(MNT_SOFTDEP); + MNT_FLAG(MNT_NOSYMFOLLOW); + MNT_FLAG(MNT_GJOURNAL); + MNT_FLAG(MNT_MULTILABEL); + MNT_FLAG(MNT_ACLS); + MNT_FLAG(MNT_NOATIME); + MNT_FLAG(MNT_NOCLUSTERR); + MNT_FLAG(MNT_NOCLUSTERW); + MNT_FLAG(MNT_SUJ); + MNT_FLAG(MNT_EXRDONLY); + MNT_FLAG(MNT_EXPORTED); + MNT_FLAG(MNT_DEFEXPORTED); + MNT_FLAG(MNT_EXPORTANON); + MNT_FLAG(MNT_EXKERB); + MNT_FLAG(MNT_EXPUBLIC); + MNT_FLAG(MNT_LOCAL); + MNT_FLAG(MNT_QUOTA); + MNT_FLAG(MNT_ROOTFS); + MNT_FLAG(MNT_USER); + MNT_FLAG(MNT_IGNORE); + MNT_FLAG(MNT_UPDATE); + MNT_FLAG(MNT_DELEXPORT); + MNT_FLAG(MNT_RELOAD); + MNT_FLAG(MNT_FORCE); + MNT_FLAG(MNT_SNAPSHOT); + MNT_FLAG(MNT_BYFSID); +#undef MNT_FLAG + if (mflags != 0) { + if (buf[0] != '\0') + strlcat(buf, ", ", sizeof(buf)); + snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), + "0x%016jx", mflags); + } + db_printf(" mnt_flag = %s\n", buf); + + buf[0] = '\0'; + flags = mp->mnt_kern_flag; +#define MNT_KERN_FLAG(flag) do { \ + if (flags & (flag)) { \ + if (buf[0] != '\0') \ + strlcat(buf, ", ", sizeof(buf)); \ + strlcat(buf, (#flag) + 5, sizeof(buf)); \ + flags &= ~(flag); \ + } \ +} while (0) + MNT_KERN_FLAG(MNTK_UNMOUNTF); + MNT_KERN_FLAG(MNTK_ASYNC); + MNT_KERN_FLAG(MNTK_SOFTDEP); + MNT_KERN_FLAG(MNTK_DRAINING); + MNT_KERN_FLAG(MNTK_REFEXPIRE); + MNT_KERN_FLAG(MNTK_EXTENDED_SHARED); + MNT_KERN_FLAG(MNTK_SHARED_WRITES); + MNT_KERN_FLAG(MNTK_NO_IOPF); + MNT_KERN_FLAG(MNTK_VGONE_UPPER); + MNT_KERN_FLAG(MNTK_VGONE_WAITER); + MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT); + MNT_KERN_FLAG(MNTK_MARKER); + MNT_KERN_FLAG(MNTK_USES_BCACHE); + MNT_KERN_FLAG(MNTK_NOASYNC); + MNT_KERN_FLAG(MNTK_UNMOUNT); + MNT_KERN_FLAG(MNTK_MWAIT); + MNT_KERN_FLAG(MNTK_SUSPEND); + MNT_KERN_FLAG(MNTK_SUSPEND2); + MNT_KERN_FLAG(MNTK_SUSPENDED); + MNT_KERN_FLAG(MNTK_LOOKUP_SHARED); + MNT_KERN_FLAG(MNTK_NOKNOTE); +#undef MNT_KERN_FLAG + if (flags != 0) { + if (buf[0] != '\0') + strlcat(buf, ", ", sizeof(buf)); + snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), + "0x%08x", flags); + } + db_printf(" mnt_kern_flag = %s\n", buf); + + db_printf(" mnt_opt = "); + opt = TAILQ_FIRST(mp->mnt_opt); + if (opt != NULL) { + db_printf("%s", opt->name); + opt = TAILQ_NEXT(opt, link); + while (opt != NULL) { + db_printf(", %s", opt->name); + opt = TAILQ_NEXT(opt, link); + } + } + db_printf("\n"); + + sp = &mp->mnt_stat; + db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx " + "bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju " + "ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju " + "asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n", + (u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags, + (uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize, + (uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree, + (intmax_t)sp->f_bavail, (uintmax_t)sp->f_files, + (intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites, + (uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads, + (uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax, + (u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]); + + db_printf(" mnt_cred = { uid=%u ruid=%u", + (u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid); + if (jailed(mp->mnt_cred)) + db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id); + db_printf(" }\n"); + db_printf(" mnt_ref = %d\n", mp->mnt_ref); + db_printf(" mnt_gen = %d\n", mp->mnt_gen); + db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize); + db_printf(" mnt_activevnodelistsize = %d\n", + mp->mnt_activevnodelistsize); + db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount); + db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen); + db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max); + db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed); + db_printf(" mnt_lockref = %d\n", mp->mnt_lockref); + db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes); + db_printf(" mnt_secondary_accwrites = %d\n", + mp->mnt_secondary_accwrites); + db_printf(" mnt_gjprovider = %s\n", + mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL"); + + db_printf("\n\nList of active vnodes\n"); + TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) { + if (vp->v_type != VMARKER) { + vn_printf(vp, "vnode "); + if (db_pager_quit) + break; + } + } + db_printf("\n\nList of inactive vnodes\n"); + TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { + if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) { + vn_printf(vp, "vnode "); + if (db_pager_quit) + break; + } + } +} +#endif /* DDB */ + +/* + * Fill in a struct xvfsconf based on a struct vfsconf. + */ +static int +vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp) +{ + struct xvfsconf xvfsp; + + bzero(&xvfsp, sizeof(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; + return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); +} + +#ifdef COMPAT_FREEBSD32 +struct xvfsconf32 { + uint32_t vfc_vfsops; + char vfc_name[MFSNAMELEN]; + int32_t vfc_typenum; + int32_t vfc_refcount; + int32_t vfc_flags; + uint32_t vfc_next; +}; + +static int +vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp) +{ + struct xvfsconf32 xvfsp; + + bzero(&xvfsp, sizeof(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; + return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); +} +#endif + +/* + * Top level filesystem related information gathering. + */ +static int +sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) +{ + struct vfsconf *vfsp; + int error; + + error = 0; + vfsconf_slock(); + TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { +#ifdef COMPAT_FREEBSD32 + if (req->flags & SCTL_MASK32) + error = vfsconf2x32(req, vfsp); + else +#endif + error = vfsconf2x(req, vfsp); + if (error) + break; + } + vfsconf_sunlock(); + return (error); +} + +SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD | + CTLFLAG_MPSAFE, 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; + + log(LOG_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 */ + vfsconf_slock(); + TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { + if (vfsp->vfc_typenum == name[2]) + break; + } + vfsconf_sunlock(); + if (vfsp == NULL) + return (EOPNOTSUPP); +#ifdef COMPAT_FREEBSD32 + if (req->flags & SCTL_MASK32) + return (vfsconf2x32(req, vfsp)); + else +#endif + return (vfsconf2x(req, vfsp)); + } + return (EOPNOTSUPP); +} + +static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP | + CTLFLAG_MPSAFE, 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; + + vfsconf_slock(); + 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 != 0) { + vfsconf_sunlock(); + return (error); + } + } + vfsconf_sunlock(); + 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 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, MBF_NOWAIT | MBF_MNTLSTLOCK)) + 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); + 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 | + CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode", + ""); +#endif + +static void +unmount_or_warn(struct mount *mp) +{ + int error; + + error = dounmount(mp, MNT_FORCE, curthread); + if (error != 0) { + printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); + if (error == EBUSY) + printf("BUSY)\n"); + else + printf("%d)\n", error); + } +} + +/* + * Unmount all filesystems. The list is traversed in reverse order + * of mounting to avoid dependencies. + */ +void +vfs_unmountall(void) +{ + struct mount *mp, *tmp; + + CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__); + + /* + * Since this only runs when rebooting, it is not interlocked. + */ + TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) { + vfs_ref(mp); + + /* + * Forcibly unmounting "/dev" before "/" would prevent clean + * unmount of the latter. + */ + if (mp == rootdevmp) + continue; + + unmount_or_warn(mp); + } + + if (rootdevmp != NULL) + unmount_or_warn(rootdevmp); +} + +/* + * 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, *mvp; + struct vm_object *obj; + + CTR2(KTR_VFS, "%s: mp %p", __func__, mp); + + vnlru_return_batch(mp); + + MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) { + obj = vp->v_object; + if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 && + (flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) { + if (!vget(vp, + LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, + curthread)) { + if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ + vput(vp); + continue; + } + + obj = vp->v_object; + if (obj != NULL) { + VM_OBJECT_WLOCK(obj); + vm_object_page_clean(obj, 0, 0, + flags == MNT_WAIT ? + OBJPC_SYNC : OBJPC_NOSYNC); + VM_OBJECT_WUNLOCK(obj); + } + vput(vp); + } + } else + VI_UNLOCK(vp); + } +} + +static void +destroy_vpollinfo_free(struct vpollinfo *vi) +{ + + knlist_destroy(&vi->vpi_selinfo.si_note); + mtx_destroy(&vi->vpi_lock); + uma_zfree(vnodepoll_zone, vi); +} + +static void +destroy_vpollinfo(struct vpollinfo *vi) +{ + + knlist_clear(&vi->vpi_selinfo.si_note, 1); + seldrain(&vi->vpi_selinfo); + destroy_vpollinfo_free(vi); +} + +/* + * Initialize per-vnode helper structure to hold poll-related state. + */ +void +v_addpollinfo(struct vnode *vp) +{ + struct vpollinfo *vi; + + if (vp->v_pollinfo != NULL) + return; + vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO); + mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); + knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock, + vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked); + VI_LOCK(vp); + if (vp->v_pollinfo != NULL) { + VI_UNLOCK(vp); + destroy_vpollinfo_free(vi); + return; + } + vp->v_pollinfo = vi; + VI_UNLOCK(vp); +} + +/* + * 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(struct vnode *vp, struct thread *td, int events) +{ + + 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_lock1 = vop_stdlock, /* lock */ + .vop_unlock = vop_stdunlock, /* unlock */ + .vop_islocked = vop_stdislocked, /* islocked */ +}; + +/* + * Create a new filesystem syncer vnode for the specified mount point. + */ +void +vfs_allocate_syncvnode(struct mount *mp) +{ + struct vnode *vp; + struct bufobj *bo; + static long start, incr, next; + int error; + + /* Allocate a new vnode */ + error = getnewvnode("syncer", mp, &sync_vnodeops, &vp); + if (error != 0) + panic("vfs_allocate_syncvnode: getnewvnode() failed"); + vp->v_type = VNON; + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); + vp->v_vflag |= VV_FORCEINSMQ; + error = insmntque(vp, mp); + if (error != 0) + panic("vfs_allocate_syncvnode: insmntque() failed"); + vp->v_vflag &= ~VV_FORCEINSMQ; + VOP_UNLOCK(vp, 0); + /* + * 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; + } + bo = &vp->v_bufobj; + BO_LOCK(bo); + vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0); + /* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */ + mtx_lock(&sync_mtx); + sync_vnode_count++; + if (mp->mnt_syncer == NULL) { + mp->mnt_syncer = vp; + vp = NULL; + } + mtx_unlock(&sync_mtx); + BO_UNLOCK(bo); + if (vp != NULL) { + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); + vgone(vp); + vput(vp); + } +} + +void +vfs_deallocate_syncvnode(struct mount *mp) +{ + struct vnode *vp; + + mtx_lock(&sync_mtx); + vp = mp->mnt_syncer; + if (vp != NULL) + mp->mnt_syncer = NULL; + mtx_unlock(&sync_mtx); + if (vp != NULL) + vrele(vp); +} + +/* + * Do a lazy sync of the filesystem. + */ +static int +sync_fsync(struct vop_fsync_args *ap) +{ + struct vnode *syncvp = ap->a_vp; + struct mount *mp = syncvp->v_mount; + int error, save; + 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. + */ + if (vfs_busy(mp, MBF_NOWAIT) != 0) + return (0); + if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { + vfs_unbusy(mp); + return (0); + } + save = curthread_pflags_set(TDP_SYNCIO); + vfs_msync(mp, MNT_NOWAIT); + error = VFS_SYNC(mp, MNT_LAZY); + curthread_pflags_restore(save); + vn_finished_write(mp); + vfs_unbusy(mp); + return (error); +} + +/* + * The syncer vnode is no referenced. + */ +static int +sync_inactive(struct vop_inactive_args *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(struct vop_reclaim_args *ap) +{ + struct vnode *vp = ap->a_vp; + struct bufobj *bo; + + bo = &vp->v_bufobj; + BO_LOCK(bo); + mtx_lock(&sync_mtx); + if (vp->v_mount->mnt_syncer == vp) + vp->v_mount->mnt_syncer = NULL; + if (bo->bo_flag & BO_ONWORKLST) { + LIST_REMOVE(bo, bo_synclist); + syncer_worklist_len--; + sync_vnode_count--; + bo->bo_flag &= ~BO_ONWORKLST; + } + mtx_unlock(&sync_mtx); + BO_UNLOCK(bo); + + return (0); +} + +/* + * Check if vnode represents a disk device + */ +int +vn_isdisk(struct vnode *vp, int *errp) +{ + int error; + + if (vp->v_type != VCHR) { + error = ENOTBLK; + goto out; + } + error = 0; + dev_lock(); + 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(); +out: + 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(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid, + accmode_t accmode, struct ucred *cred, int *privused) +{ + accmode_t dac_granted; + accmode_t priv_granted; + + KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0, + ("invalid bit in accmode")); + KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE), + ("VAPPEND without VWRITE")); + + /* + * 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 ((accmode & dac_granted) == accmode) + 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 ((accmode & dac_granted) == accmode) + 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 ((accmode & dac_granted) == accmode) + return (0); + +privcheck: + /* + * Build a privilege mask to determine if the set of privileges + * satisfies the requirements when combined with the granted mask + * from above. For each privilege, if the privilege is required, + * bitwise or the request type onto the priv_granted mask. + */ + priv_granted = 0; + + if (type == VDIR) { + /* + * For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC + * requests, instead of PRIV_VFS_EXEC. + */ + if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && + !priv_check_cred(cred, PRIV_VFS_LOOKUP, 0)) + priv_granted |= VEXEC; + } else { + /* + * Ensure that at least one execute bit is on. Otherwise, + * a privileged user will always succeed, and we don't want + * this to happen unless the file really is executable. + */ + if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) && + (file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 && + !priv_check_cred(cred, PRIV_VFS_EXEC, 0)) + priv_granted |= VEXEC; + } + + if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) && + !priv_check_cred(cred, PRIV_VFS_READ, 0)) + priv_granted |= VREAD; + + if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) && + !priv_check_cred(cred, PRIV_VFS_WRITE, 0)) + priv_granted |= (VWRITE | VAPPEND); + + if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) && + !priv_check_cred(cred, PRIV_VFS_ADMIN, 0)) + priv_granted |= VADMIN; + + if ((accmode & (priv_granted | dac_granted)) == accmode) { + /* XXX audit: privilege used */ + if (privused != NULL) + *privused = 1; + return (0); + } + + return ((accmode & 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, accmode_t accmode) +{ + + /* + * Kernel-invoked always succeeds. + */ + if (cred == NOCRED) + return (0); + + /* + * Do not allow privileged processes in jail to directly manipulate + * system attributes. + */ + switch (attrnamespace) { + case EXTATTR_NAMESPACE_SYSTEM: + /* Potentially should be: return (EPERM); */ + return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0)); + case EXTATTR_NAMESPACE_USER: + return (VOP_ACCESS(vp, accmode, cred, td)); + default: + return (EPERM); + } +} + +#ifdef DEBUG_VFS_LOCKS +/* + * This only exists to suppress warnings from unlocked specfs accesses. It is + * no longer ok to have an unlocked VFS. + */ +#define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \ + (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, + "Drop into debugger on lock violation"); + +int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */ +SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex, + 0, "Check for interlock across VOPs"); + +int vfs_badlock_print = 1; /* Print lock violations. */ +SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print, + 0, "Print lock violations"); + +int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */ +SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode, + 0, "Print vnode details on lock violations"); + +#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, "Print backtrace at lock violations"); +#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_vnode) + vn_printf(vp, "vnode "); + if (vfs_badlock_print) + printf("%s: %p %s\n", str, (void *)vp, msg); + if (vfs_badlock_ddb) + kdb_enter(KDB_WHY_VFSLOCK, "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) +{ + int locked; + + if (!IGNORE_LOCK(vp)) { + locked = VOP_ISLOCKED(vp); + if (locked == 0 || locked == LK_EXCLOTHER) + vfs_badlock("is not locked but should be", str, vp); + } +} + +void +assert_vop_unlocked(struct vnode *vp, const char *str) +{ + + if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE) + vfs_badlock("is locked but should not be", str, vp); +} + +void +assert_vop_elocked(struct vnode *vp, const char *str) +{ + + if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE) + vfs_badlock("is not exclusive locked but should be", str, vp); +} +#endif /* DEBUG_VFS_LOCKS */ + +void +vop_rename_fail(struct vop_rename_args *ap) +{ + + if (ap->a_tvp != NULL) + vput(ap->a_tvp); + if (ap->a_tdvp == ap->a_tvp) + vrele(ap->a_tdvp); + else + vput(ap->a_tdvp); + vrele(ap->a_fdvp); + vrele(ap->a_fvp); +} + +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->v_vnlock != a->a_fdvp->v_vnlock && + (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock)) + ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked"); + if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock) + ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp 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); +} + +#ifdef DEBUG_VFS_LOCKS +void +vop_strategy_pre(void *ap) +{ + 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 (panicstr == NULL && !BUF_ISLOCKED(bp)) { + if (vfs_badlock_print) + printf( + "VOP_STRATEGY: bp is not locked but should be\n"); + if (vfs_badlock_ddb) + kdb_enter(KDB_WHY_VFSLOCK, "lock violation"); + } +} + +void +vop_lock_pre(void *ap) +{ + struct vop_lock1_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_lock1_args *a = ap; + + ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); + if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0) + ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); +} + +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"); +} +#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_deleteextattr_post(void *ap, int rc) +{ + struct vop_deleteextattr_args *a = ap; + + if (!rc) + VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB); +} + +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_reclaim_post(void *ap, int rc) +{ + struct vop_reclaim_args *a = ap; + + if (!rc) + VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE); +} + +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; + long hint; + + if (!rc) { + hint = NOTE_WRITE; + if (a->a_fdvp == a->a_tdvp) { + if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR) + hint |= NOTE_LINK; + VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); + VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); + } else { + hint |= NOTE_EXTEND; + if (a->a_fvp->v_type == VDIR) + hint |= NOTE_LINK; + VFS_KNOTE_UNLOCKED(a->a_fdvp, hint); + + if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL && + a->a_tvp->v_type == VDIR) + hint &= ~NOTE_LINK; + VFS_KNOTE_UNLOCKED(a->a_tdvp, hint); + } + + 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_setextattr_post(void *ap, int rc) +{ + struct vop_setextattr_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); +} + +void +vop_open_post(void *ap, int rc) +{ + struct vop_open_args *a = ap; + + if (!rc) + VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN); +} + +void +vop_close_post(void *ap, int rc) +{ + struct vop_close_args *a = ap; + + if (!rc && (a->a_cred != NOCRED || /* filter out revokes */ + (a->a_vp->v_iflag & VI_DOOMED) == 0)) { + VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ? + NOTE_CLOSE_WRITE : NOTE_CLOSE); + } +} + +void +vop_read_post(void *ap, int rc) +{ + struct vop_read_args *a = ap; + + if (!rc) + VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); +} + +void +vop_readdir_post(void *ap, int rc) +{ + struct vop_readdir_args *a = ap; + + if (!rc) + VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ); +} + +static struct knlist fs_knlist; + +static void +vfs_event_init(void *arg) +{ + knlist_init_mtx(&fs_knlist, NULL); +} +/* XXX - correct order? */ +SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL); + +void +vfs_event_signal(fsid_t *fsid, uint32_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 = { + .f_isfd = 0, + .f_attach = filt_fsattach, + .f_detach = filt_fsdetach, + .f_event = 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) { + vfs_rel(mp); + return (EINVAL); + } + VCTLTOREQ(&vc, req); + error = VFS_SYSCTL(mp, vc.vc_op, req); + vfs_rel(mp); + return (error); +} + +SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | 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 = { + .f_isfd = 1, + .f_detach = filt_vfsdetach, + .f_event = filt_vfsread +}; +static struct filterops vfswrite_filtops = { + .f_isfd = 1, + .f_detach = filt_vfsdetach, + .f_event = filt_vfswrite +}; +static struct filterops vfsvnode_filtops = { + .f_isfd = 1, + .f_detach = filt_vfsdetach, + .f_event = filt_vfsvnode +}; + +static void +vfs_knllock(void *arg) +{ + struct vnode *vp = arg; + + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); +} + +static void +vfs_knlunlock(void *arg) +{ + struct vnode *vp = arg; + + VOP_UNLOCK(vp, 0); +} + +static void +vfs_knl_assert_locked(void *arg) +{ +#ifdef DEBUG_VFS_LOCKS + struct vnode *vp = arg; + + ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked"); +#endif +} + +static void +vfs_knl_assert_unlocked(void *arg) +{ +#ifdef DEBUG_VFS_LOCKS + struct vnode *vp = arg; + + ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked"); +#endif +} + +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; + + v_addpollinfo(vp); + if (vp->v_pollinfo == NULL) + return (ENOMEM); + knl = &vp->v_pollinfo->vpi_selinfo.si_note; + vhold(vp); + 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); + vdrop(vp); +} + +/*ARGSUSED*/ +static int +filt_vfsread(struct knote *kn, long hint) +{ + struct vnode *vp = (struct vnode *)kn->kn_hook; + struct vattr va; + int res; + + /* + * filesystem is gone, so set the EOF flag and schedule + * the knote for deletion. + */ + if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { + VI_LOCK(vp); + kn->kn_flags |= (EV_EOF | EV_ONESHOT); + VI_UNLOCK(vp); + return (1); + } + + if (VOP_GETATTR(vp, &va, curthread->td_ucred)) + return (0); + + VI_LOCK(vp); + kn->kn_data = va.va_size - kn->kn_fp->f_offset; + res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0; + VI_UNLOCK(vp); + return (res); +} + +/*ARGSUSED*/ +static int +filt_vfswrite(struct knote *kn, long hint) +{ + struct vnode *vp = (struct vnode *)kn->kn_hook; + + VI_LOCK(vp); + + /* + * filesystem is gone, so set the EOF flag and schedule + * the knote for deletion. + */ + if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) + kn->kn_flags |= (EV_EOF | EV_ONESHOT); + + kn->kn_data = 0; + VI_UNLOCK(vp); + return (1); +} + +static int +filt_vfsvnode(struct knote *kn, long hint) +{ + struct vnode *vp = (struct vnode *)kn->kn_hook; + int res; + + VI_LOCK(vp); + if (kn->kn_sfflags & hint) + kn->kn_fflags |= hint; + if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) { + kn->kn_flags |= EV_EOF; + VI_UNLOCK(vp); + return (1); + } + res = (kn->kn_fflags != 0); + VI_UNLOCK(vp); + return (res); +} + +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); + + KASSERT(ap->a_cookies, + ("NULL ap->a_cookies value with non-NULL ap->a_ncookies!")); + + *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; + *ap->a_ncookies += 1; + return (0); +} + +/* + * Mark for update the access time of the file if the filesystem + * supports VOP_MARKATIME. This functionality is used by execve and + * mmap, so we want to avoid the I/O implied by directly setting + * va_atime for the sake of efficiency. + */ +void +vfs_mark_atime(struct vnode *vp, struct ucred *cred) +{ + struct mount *mp; + + mp = vp->v_mount; + ASSERT_VOP_LOCKED(vp, "vfs_mark_atime"); + if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) + (void)VOP_MARKATIME(vp); +} + +/* + * The purpose of this routine is to remove granularity from accmode_t, + * reducing it into standard unix access bits - VEXEC, VREAD, VWRITE, + * VADMIN and VAPPEND. + * + * If it returns 0, the caller is supposed to continue with the usual + * access checks using 'accmode' as modified by this routine. If it + * returns nonzero value, the caller is supposed to return that value + * as errno. + * + * Note that after this routine runs, accmode may be zero. + */ +int +vfs_unixify_accmode(accmode_t *accmode) +{ + /* + * There is no way to specify explicit "deny" rule using + * file mode or POSIX.1e ACLs. + */ + if (*accmode & VEXPLICIT_DENY) { + *accmode = 0; + return (0); + } + + /* + * None of these can be translated into usual access bits. + * Also, the common case for NFSv4 ACLs is to not contain + * either of these bits. Caller should check for VWRITE + * on the containing directory instead. + */ + if (*accmode & (VDELETE_CHILD | VDELETE)) + return (EPERM); + + if (*accmode & VADMIN_PERMS) { + *accmode &= ~VADMIN_PERMS; + *accmode |= VADMIN; + } + + /* + * There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL + * or VSYNCHRONIZE using file mode or POSIX.1e ACL. + */ + *accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE); + + return (0); +} + +/* + * These are helper functions for filesystems to traverse all + * their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h. + * + * This interface replaces MNT_VNODE_FOREACH. + */ + +MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); + +struct vnode * +__mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) +{ + struct vnode *vp; + + if (should_yield()) + kern_yield(PRI_USER); + MNT_ILOCK(mp); + KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); + for (vp = TAILQ_NEXT(*mvp, v_nmntvnodes); vp != NULL; + vp = TAILQ_NEXT(vp, v_nmntvnodes)) { + /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ + if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) + continue; + VI_LOCK(vp); + if ((vp->v_iflag & VI_DOOMED) != 0) { + VI_UNLOCK(vp); + continue; + } + break; + } + if (vp == NULL) { + __mnt_vnode_markerfree_all(mvp, mp); + /* MNT_IUNLOCK(mp); -- done in above function */ + mtx_assert(MNT_MTX(mp), MA_NOTOWNED); + return (NULL); + } + TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); + TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); + MNT_IUNLOCK(mp); + return (vp); +} + +struct vnode * +__mnt_vnode_first_all(struct vnode **mvp, struct mount *mp) +{ + struct vnode *vp; + + *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); + MNT_ILOCK(mp); + MNT_REF(mp); + (*mvp)->v_mount = mp; + (*mvp)->v_type = VMARKER; + + TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { + /* Allow a racy peek at VI_DOOMED to save a lock acquisition. */ + if (vp->v_type == VMARKER || (vp->v_iflag & VI_DOOMED) != 0) + continue; + VI_LOCK(vp); + if ((vp->v_iflag & VI_DOOMED) != 0) { + VI_UNLOCK(vp); + continue; + } + break; + } + if (vp == NULL) { + MNT_REL(mp); + MNT_IUNLOCK(mp); + free(*mvp, M_VNODE_MARKER); + *mvp = NULL; + return (NULL); + } + TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); + MNT_IUNLOCK(mp); + return (vp); +} + +void +__mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp) +{ + + if (*mvp == NULL) { + MNT_IUNLOCK(mp); + return; + } + + mtx_assert(MNT_MTX(mp), MA_OWNED); + + KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); + TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); + MNT_REL(mp); + MNT_IUNLOCK(mp); + free(*mvp, M_VNODE_MARKER); + *mvp = NULL; +} + +/* + * These are helper functions for filesystems to traverse their + * active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h + */ +static void +mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) +{ + + KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); + + MNT_ILOCK(mp); + MNT_REL(mp); + MNT_IUNLOCK(mp); + free(*mvp, M_VNODE_MARKER); + *mvp = NULL; +} + +/* + * Relock the mp mount vnode list lock with the vp vnode interlock in the + * conventional lock order during mnt_vnode_next_active iteration. + * + * On entry, the mount vnode list lock is held and the vnode interlock is not. + * The list lock is dropped and reacquired. On success, both locks are held. + * On failure, the mount vnode list lock is held but the vnode interlock is + * not, and the procedure may have yielded. + */ +static bool +mnt_vnode_next_active_relock(struct vnode *mvp, struct mount *mp, + struct vnode *vp) +{ + const struct vnode *tmp; + bool held, ret; + + VNASSERT(mvp->v_mount == mp && mvp->v_type == VMARKER && + TAILQ_NEXT(mvp, v_actfreelist) != NULL, mvp, + ("%s: bad marker", __func__)); + VNASSERT(vp->v_mount == mp && vp->v_type != VMARKER, vp, + ("%s: inappropriate vnode", __func__)); + ASSERT_VI_UNLOCKED(vp, __func__); + mtx_assert(&mp->mnt_listmtx, MA_OWNED); + + ret = false; + + TAILQ_REMOVE(&mp->mnt_activevnodelist, mvp, v_actfreelist); + TAILQ_INSERT_BEFORE(vp, mvp, v_actfreelist); + + /* + * Use a hold to prevent vp from disappearing while the mount vnode + * list lock is dropped and reacquired. Normally a hold would be + * acquired with vhold(), but that might try to acquire the vnode + * interlock, which would be a LOR with the mount vnode list lock. + */ + held = refcount_acquire_if_not_zero(&vp->v_holdcnt); + mtx_unlock(&mp->mnt_listmtx); + if (!held) + goto abort; + VI_LOCK(vp); + if (!refcount_release_if_not_last(&vp->v_holdcnt)) { + vdropl(vp); + goto abort; + } + mtx_lock(&mp->mnt_listmtx); + + /* + * Determine whether the vnode is still the next one after the marker, + * excepting any other markers. If the vnode has not been doomed by + * vgone() then the hold should have ensured that it remained on the + * active list. If it has been doomed but is still on the active list, + * don't abort, but rather skip over it (avoid spinning on doomed + * vnodes). + */ + tmp = mvp; + do { + tmp = TAILQ_NEXT(tmp, v_actfreelist); + } while (tmp != NULL && tmp->v_type == VMARKER); + if (tmp != vp) { + mtx_unlock(&mp->mnt_listmtx); + VI_UNLOCK(vp); + goto abort; + } + + ret = true; + goto out; +abort: + maybe_yield(); + mtx_lock(&mp->mnt_listmtx); +out: + if (ret) + ASSERT_VI_LOCKED(vp, __func__); + else + ASSERT_VI_UNLOCKED(vp, __func__); + mtx_assert(&mp->mnt_listmtx, MA_OWNED); + return (ret); +} + +static struct vnode * +mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) +{ + struct vnode *vp, *nvp; + + mtx_assert(&mp->mnt_listmtx, MA_OWNED); + KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); +restart: + vp = TAILQ_NEXT(*mvp, v_actfreelist); + while (vp != NULL) { + if (vp->v_type == VMARKER) { + vp = TAILQ_NEXT(vp, v_actfreelist); + continue; + } + /* + * Try-lock because this is the wrong lock order. If that does + * not succeed, drop the mount vnode list lock and try to + * reacquire it and the vnode interlock in the right order. + */ + if (!VI_TRYLOCK(vp) && + !mnt_vnode_next_active_relock(*mvp, mp, vp)) + goto restart; + KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp)); + KASSERT(vp->v_mount == mp || vp->v_mount == NULL, + ("alien vnode on the active list %p %p", vp, mp)); + if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0) + break; + nvp = TAILQ_NEXT(vp, v_actfreelist); + VI_UNLOCK(vp); + vp = nvp; + } + TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); + + /* Check if we are done */ + if (vp == NULL) { + mtx_unlock(&mp->mnt_listmtx); + mnt_vnode_markerfree_active(mvp, mp); + return (NULL); + } + TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist); + mtx_unlock(&mp->mnt_listmtx); + ASSERT_VI_LOCKED(vp, "active iter"); + KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp)); + return (vp); +} + +struct vnode * +__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) +{ + + if (should_yield()) + kern_yield(PRI_USER); + mtx_lock(&mp->mnt_listmtx); + return (mnt_vnode_next_active(mvp, mp)); +} + +struct vnode * +__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp) +{ + struct vnode *vp; + + *mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO); + MNT_ILOCK(mp); + MNT_REF(mp); + MNT_IUNLOCK(mp); + (*mvp)->v_type = VMARKER; + (*mvp)->v_mount = mp; + + mtx_lock(&mp->mnt_listmtx); + vp = TAILQ_FIRST(&mp->mnt_activevnodelist); + if (vp == NULL) { + mtx_unlock(&mp->mnt_listmtx); + mnt_vnode_markerfree_active(mvp, mp); + return (NULL); + } + TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist); + return (mnt_vnode_next_active(mvp, mp)); +} + +void +__mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp) +{ + + if (*mvp == NULL) + return; + + mtx_lock(&mp->mnt_listmtx); + TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist); + mtx_unlock(&mp->mnt_listmtx); + mnt_vnode_markerfree_active(mvp, mp); +} + +int +vn_dir_check_exec(struct vnode *vp, struct componentname *cnp) +{ + + if ((cnp->cn_flags & NOEXECCHECK) != 0) { + cnp->cn_flags &= ~NOEXECCHECK; + return (0); + } + + return (VOP_ACCESS(vp, VEXEC, cnp->cn_cred, cnp->cn_thread)); +} |