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a194c44001
freebsd-skq/sys/kern/vfs_subr.c
peter a194c44001 If we were called to allocate a vnode that is not associated with a 
mount point, do not dereference the NULL mp argument.
2001-12-13 23:46:01 +00:00

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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
* $FreeBSD$
*/
/*
* External virtual filesystem routines
*/
#include "opt_ddb.h"
#include "opt_ffs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/vnode.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_zone.h>
static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
static void addalias __P((struct vnode *vp, dev_t nvp_rdev));
static void insmntque __P((struct vnode *vp, struct mount *mp));
static void vclean __P((struct vnode *vp, int flags, struct thread *td));
/*
* Number of vnodes in existence. Increased whenever getnewvnode()
* allocates a new vnode, never decreased.
*/
static unsigned long numvnodes;
SYSCTL_LONG(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
/*
* Conversion tables for conversion from vnode types to inode formats
* and back.
*/
enum vtype iftovt_tab[16] = {
VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
};
int vttoif_tab[9] = {
0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
S_IFSOCK, S_IFIFO, S_IFMT,
};
/*
* List of vnodes that are ready for recycling.
*/
static TAILQ_HEAD(freelst, vnode) vnode_free_list;
/*
* Minimum number of free vnodes. If there are fewer than this free vnodes,
* getnewvnode() will return a newly allocated vnode.
*/
static u_long wantfreevnodes = 25;
SYSCTL_LONG(_debug, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
/* Number of vnodes in the free list. */
static u_long freevnodes = 0;
SYSCTL_LONG(_debug, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
#if 0
/* Number of vnode allocation. */
static u_long vnodeallocs = 0;
SYSCTL_LONG(_debug, OID_AUTO, vnodeallocs, CTLFLAG_RD, &vnodeallocs, 0, "");
/* Period of vnode recycle from namecache in vnode allocation times. */
static u_long vnoderecycleperiod = 1000;
SYSCTL_LONG(_debug, OID_AUTO, vnoderecycleperiod, CTLFLAG_RW, &vnoderecycleperiod, 0, "");
/* Minimum number of total vnodes required to invoke vnode recycle from namecache. */
static u_long vnoderecyclemintotalvn = 2000;
SYSCTL_LONG(_debug, OID_AUTO, vnoderecyclemintotalvn, CTLFLAG_RW, &vnoderecyclemintotalvn, 0, "");
/* Minimum number of free vnodes required to invoke vnode recycle from namecache. */
static u_long vnoderecycleminfreevn = 2000;
SYSCTL_LONG(_debug, OID_AUTO, vnoderecycleminfreevn, CTLFLAG_RW, &vnoderecycleminfreevn, 0, "");
/* Number of vnodes attempted to recycle at a time. */
static u_long vnoderecyclenumber = 3000;
SYSCTL_LONG(_debug, OID_AUTO, vnoderecyclenumber, CTLFLAG_RW, &vnoderecyclenumber, 0, "");
#endif
/*
* Various variables used for debugging the new implementation of
* reassignbuf().
* XXX these are probably of (very) limited utility now.
*/
static int reassignbufcalls;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
static int reassignbufloops;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufloops, CTLFLAG_RW, &reassignbufloops, 0, "");
static int reassignbufsortgood;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortgood, CTLFLAG_RW, &reassignbufsortgood, 0, "");
static int reassignbufsortbad;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad, 0, "");
/* Set to 0 for old insertion-sort based reassignbuf, 1 for modern method. */
static int reassignbufmethod = 1;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, "");
static int nameileafonly = 0;
SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, "");
#ifdef ENABLE_VFS_IOOPT
/* See NOTES for a description of this setting. */
int vfs_ioopt = 0;
SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
#endif
/* List of mounted filesystems. */
struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
/* For any iteration/modification of mountlist */
struct mtx mountlist_mtx;
/* For any iteration/modification of mnt_vnodelist */
struct mtx mntvnode_mtx;
/*
* Cache for the mount type id assigned to NFS. This is used for
* special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c.
*/
int nfs_mount_type = -1;
/* To keep more than one thread at a time from running vfs_getnewfsid */
static struct mtx mntid_mtx;
/* For any iteration/modification of vnode_free_list */
static struct mtx vnode_free_list_mtx;
/*
* For any iteration/modification of dev->si_hlist (linked through
* v_specnext)
*/
static struct mtx spechash_mtx;
/* Publicly exported FS */
struct nfs_public nfs_pub;
/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
static vm_zone_t vnode_zone;
/* Set to 1 to print out reclaim of active vnodes */
int prtactive = 0;
/*
* 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 = 0;
static long syncer_mask;
LIST_HEAD(synclist, vnode);
static struct synclist *syncer_workitem_pending;
#define SYNCER_MAXDELAY 32
static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
static int syncdelay = 30; /* max time to delay syncing data */
static int filedelay = 30; /* time to delay syncing files */
SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, "");
static int dirdelay = 29; /* time to delay syncing directories */
SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, "");
static int metadelay = 28; /* time to delay syncing metadata */
SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, "");
static int rushjob; /* number of slots to run ASAP */
static int stat_rush_requests; /* number of times I/O speeded up */
SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
/*
* Number of vnodes we want to exist at any one time. This is mostly used
* to size hash tables in vnode-related code. It is normally not used in
* getnewvnode(), as wantfreevnodes is normally nonzero.)
*
* XXX desiredvnodes is historical cruft and should not exist.
*/
int desiredvnodes;
SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
&desiredvnodes, 0, "Maximum number of vnodes");
static int minvnodes;
SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
&minvnodes, 0, "Minimum number of vnodes");
/*
* Initialize the vnode management data structures.
*/
static void
vntblinit(void *dummy __unused)
{
desiredvnodes = maxproc + cnt.v_page_count / 4;
minvnodes = desiredvnodes / 4;
mtx_init(&mountlist_mtx, "mountlist", MTX_DEF);
mtx_init(&mntvnode_mtx, "mntvnode", MTX_DEF);
mtx_init(&mntid_mtx, "mntid", MTX_DEF);
mtx_init(&spechash_mtx, "spechash", MTX_DEF);
TAILQ_INIT(&vnode_free_list);
mtx_init(&vnode_free_list_mtx, "vnode_free_list", MTX_DEF);
vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5);
/*
* Initialize the filesystem syncer.
*/
syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
&syncer_mask);
syncer_maxdelay = syncer_mask + 1;
}
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL)
/*
* Mark a mount point as busy. Used to synchronize access and to delay
* unmounting. Interlock is not released on failure.
*/
int
vfs_busy(mp, flags, interlkp, td)
struct mount *mp;
int flags;
struct mtx *interlkp;
struct thread *td;
{
int lkflags;
if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
if (flags & LK_NOWAIT)
return (ENOENT);
mp->mnt_kern_flag |= MNTK_MWAIT;
/*
* Since all busy locks are shared except the exclusive
* lock granted when unmounting, the only place that a
* wakeup needs to be done is at the release of the
* exclusive lock at the end of dounmount.
*/
msleep((caddr_t)mp, interlkp, PVFS, "vfs_busy", 0);
return (ENOENT);
}
lkflags = LK_SHARED | LK_NOPAUSE;
if (interlkp)
lkflags |= LK_INTERLOCK;
if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td))
panic("vfs_busy: unexpected lock failure");
return (0);
}
/*
* Free a busy filesystem.
*/
void
vfs_unbusy(mp, td)
struct mount *mp;
struct thread *td;
{
lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
}
/*
* Lookup a filesystem type, and if found allocate and initialize
* a mount structure for it.
*
* Devname is usually updated by mount(8) after booting.
*/
int
vfs_rootmountalloc(fstypename, devname, mpp)
char *fstypename;
char *devname;
struct mount **mpp;
{
struct thread *td = curthread; /* XXX */
struct vfsconf *vfsp;
struct mount *mp;
if (fstypename == NULL)
return (ENODEV);
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (!strcmp(vfsp->vfc_name, fstypename))
break;
if (vfsp == NULL)
return (ENODEV);
mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO);
lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
(void)vfs_busy(mp, LK_NOWAIT, 0, td);
TAILQ_INIT(&mp->mnt_nvnodelist);
TAILQ_INIT(&mp->mnt_reservedvnlist);
mp->mnt_vfc = vfsp;
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_flag = MNT_RDONLY;
mp->mnt_vnodecovered = NULLVP;
vfsp->vfc_refcount++;
mp->mnt_iosize_max = DFLTPHYS;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_stat.f_mntonname[0] = '/';
mp->mnt_stat.f_mntonname[1] = 0;
(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
*mpp = mp;
return (0);
}
/*
* Find an appropriate filesystem to use for the root. If a filesystem
* has not been preselected, walk through the list of known filesystems
* trying those that have mountroot routines, and try them until one
* works or we have tried them all.
*/
#ifdef notdef /* XXX JH */
int
lite2_vfs_mountroot()
{
struct vfsconf *vfsp;
extern int (*lite2_mountroot) __P((void));
int error;
if (lite2_mountroot != NULL)
return ((*lite2_mountroot)());
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
if (vfsp->vfc_mountroot == NULL)
continue;
if ((error = (*vfsp->vfc_mountroot)()) == 0)
return (0);
printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error);
}
return (ENODEV);
}
#endif
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
vfs_getvfs(fsid)
fsid_t *fsid;
{
register struct mount *mp;
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
mtx_unlock(&mountlist_mtx);
return (mp);
}
}
mtx_unlock(&mountlist_mtx);
return ((struct mount *) 0);
}
/*
* Get a new unique fsid. Try to make its val[0] unique, since this value
* will be used to create fake device numbers for stat(). Also try (but
* not so hard) make its val[0] unique mod 2^16, since some emulators only
* support 16-bit device numbers. We end up with unique val[0]'s for the
* first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
*
* Keep in mind that several mounts may be running in parallel. Starting
* the search one past where the previous search terminated is both a
* micro-optimization and a defense against returning the same fsid to
* different mounts.
*/
void
vfs_getnewfsid(mp)
struct mount *mp;
{
static u_int16_t mntid_base;
fsid_t tfsid;
int mtype;
mtx_lock(&mntid_mtx);
mtype = mp->mnt_vfc->vfc_typenum;
tfsid.val[1] = mtype;
mtype = (mtype & 0xFF) << 24;
for (;;) {
tfsid.val[0] = makeudev(255,
mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
mntid_base++;
if (vfs_getvfs(&tfsid) == NULL)
break;
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
mtx_unlock(&mntid_mtx);
}
/*
* Knob to control the precision of file timestamps:
*
* 0 = seconds only; nanoseconds zeroed.
* 1 = seconds and nanoseconds, accurate within 1/HZ.
* 2 = seconds and nanoseconds, truncated to microseconds.
* >=3 = seconds and nanoseconds, maximum precision.
*/
enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
static int timestamp_precision = TSP_SEC;
SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
&timestamp_precision, 0, "");
/*
* Get a current timestamp.
*/
void
vfs_timestamp(tsp)
struct timespec *tsp;
{
struct timeval tv;
switch (timestamp_precision) {
case TSP_SEC:
tsp->tv_sec = time_second;
tsp->tv_nsec = 0;
break;
case TSP_HZ:
getnanotime(tsp);
break;
case TSP_USEC:
microtime(&tv);
TIMEVAL_TO_TIMESPEC(&tv, tsp);
break;
case TSP_NSEC:
default:
nanotime(tsp);
break;
}
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(vap)
register struct vattr *vap;
{
vap->va_type = VNON;
vap->va_size = VNOVAL;
vap->va_bytes = VNOVAL;
vap->va_mode = VNOVAL;
vap->va_nlink = VNOVAL;
vap->va_uid = VNOVAL;
vap->va_gid = VNOVAL;
vap->va_fsid = VNOVAL;
vap->va_fileid = VNOVAL;
vap->va_blocksize = VNOVAL;
vap->va_rdev = VNOVAL;
vap->va_atime.tv_sec = VNOVAL;
vap->va_atime.tv_nsec = VNOVAL;
vap->va_mtime.tv_sec = VNOVAL;
vap->va_mtime.tv_nsec = VNOVAL;
vap->va_ctime.tv_sec = VNOVAL;
vap->va_ctime.tv_nsec = VNOVAL;
vap->va_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
* desireable to reuse such vnodes. These conditions may cause the
* number of vnodes to reach some minimum value regardless of what
* you set kern.maxvnodes to. Do not set kernl.maxvnodes too low.
*/
static void
vlrureclaim(struct mount *mp, int count)
{
struct vnode *vp;
if (mp == NULL)
return;
mtx_lock(&mntvnode_mtx);
while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) {
TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
if (vp->v_type != VNON &&
vp->v_type != VBAD &&
VMIGHTFREE(vp) && /* critical path opt */
mtx_trylock(&vp->v_interlock)
) {
mtx_unlock(&mntvnode_mtx);
if (VMIGHTFREE(vp)) {
vgonel(vp, curthread);
} else {
mtx_unlock(&vp->v_interlock);
}
mtx_lock(&mntvnode_mtx);
}
--count;
}
mtx_unlock(&mntvnode_mtx);
}
/*
* Routines having to do with the management of the vnode table.
*/
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(tag, mp, vops, vpp)
enum vtagtype tag;
struct mount *mp;
vop_t **vops;
struct vnode **vpp;
{
int s;
struct thread *td = curthread; /* XXX */
struct vnode *vp = NULL;
struct mount *vnmp;
vm_object_t object;
s = splbio();
/*
* Try to reuse vnodes if we hit the max. This situation only
* occurs in certain large-memory (2G+) situations. For the
* algorithm to be stable we have to try to reuse at least 2.
* No hysteresis should be necessary.
*/
if (numvnodes - freevnodes > desiredvnodes)
vlrureclaim(mp, 2);
/*
* Attempt to reuse a vnode already on the free list, allocating
* a new vnode if we can't find one or if we have not reached a
* good minimum for good LRU performance.
*/
mtx_lock(&vnode_free_list_mtx);
if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) {
int count;
for (count = 0; count < freevnodes; count++) {
vp = TAILQ_FIRST(&vnode_free_list);
if (vp == NULL || vp->v_usecount)
panic("getnewvnode: free vnode isn't");
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
/*
* Don't recycle if we still have cached pages or if
* we cannot get the interlock.
*/
if ((VOP_GETVOBJECT(vp, &object) == 0 &&
(object->resident_page_count ||
object->ref_count)) ||
!mtx_trylock(&vp->v_interlock)) {
TAILQ_INSERT_TAIL(&vnode_free_list, vp,
v_freelist);
vp = NULL;
continue;
}
if (LIST_FIRST(&vp->v_cache_src)) {
/*
* note: nameileafonly sysctl is temporary,
* for debugging only, and will eventually be
* removed.
*/
if (nameileafonly > 0) {
/*
* Do not reuse namei-cached directory
* vnodes that have cached
* subdirectories.
*/
if (cache_leaf_test(vp) < 0) {
mtx_unlock(&vp->v_interlock);
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
vp = NULL;
continue;
}
} else if (nameileafonly < 0 ||
vmiodirenable == 0) {
/*
* Do not reuse namei-cached directory
* vnodes if nameileafonly is -1 or
* if VMIO backing for directories is
* turned off (otherwise we reuse them
* too quickly).
*/
mtx_unlock(&vp->v_interlock);
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
vp = NULL;
continue;
}
}
/*
* Skip over it if its filesystem is being suspended.
*/
if (vn_start_write(vp, &vnmp, V_NOWAIT) == 0)
break;
mtx_unlock(&vp->v_interlock);
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
vp = NULL;
}
}
if (vp) {
vp->v_flag |= VDOOMED;
vp->v_flag &= ~VFREE;
freevnodes--;
mtx_unlock(&vnode_free_list_mtx);
cache_purge(vp);
vp->v_lease = NULL;
if (vp->v_type != VBAD) {
vgonel(vp, td);
} else {
mtx_unlock(&vp->v_interlock);
}
vn_finished_write(vnmp);
#ifdef INVARIANTS
{
int s;
if (vp->v_data)
panic("cleaned vnode isn't");
s = splbio();
if (vp->v_numoutput)
panic("Clean vnode has pending I/O's");
splx(s);
if (vp->v_writecount != 0)
panic("Non-zero write count");
}
#endif
vp->v_flag = 0;
vp->v_lastw = 0;
vp->v_lasta = 0;
vp->v_cstart = 0;
vp->v_clen = 0;
vp->v_socket = 0;
} else {
mtx_unlock(&vnode_free_list_mtx);
vp = (struct vnode *) zalloc(vnode_zone);
bzero((char *) vp, sizeof *vp);
mtx_init(&vp->v_interlock, "vnode interlock", MTX_DEF);
vp->v_dd = vp;
mtx_init(&vp->v_pollinfo.vpi_lock, "vnode pollinfo", MTX_DEF);
cache_purge(vp);
LIST_INIT(&vp->v_cache_src);
TAILQ_INIT(&vp->v_cache_dst);
numvnodes++;
}
TAILQ_INIT(&vp->v_cleanblkhd);
TAILQ_INIT(&vp->v_dirtyblkhd);
vp->v_type = VNON;
vp->v_tag = tag;
vp->v_op = vops;
lockinit(&vp->v_lock, PVFS, "vnlock", 0, LK_NOPAUSE);
insmntque(vp, mp);
*vpp = vp;
vp->v_usecount = 1;
vp->v_data = 0;
splx(s);
vfs_object_create(vp, td, td->td_proc->p_ucred);
#if 0
vnodeallocs++;
if (vnodeallocs % vnoderecycleperiod == 0 &&
freevnodes < vnoderecycleminfreevn &&
vnoderecyclemintotalvn < numvnodes) {
/* Recycle vnodes. */
cache_purgeleafdirs(vnoderecyclenumber);
}
#endif
return (0);
}
/*
* Move a vnode from one mount queue to another.
*/
static void
insmntque(vp, mp)
register struct vnode *vp;
register struct mount *mp;
{
mtx_lock(&mntvnode_mtx);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes);
/*
* Insert into list of vnodes for the new mount point, if available.
*/
if ((vp->v_mount = mp) == NULL) {
mtx_unlock(&mntvnode_mtx);
return;
}
TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
mtx_unlock(&mntvnode_mtx);
}
/*
* Update outstanding I/O count and do wakeup if requested.
*/
void
vwakeup(bp)
register struct buf *bp;
{
register struct vnode *vp;
bp->b_flags &= ~B_WRITEINPROG;
if ((vp = bp->b_vp)) {
vp->v_numoutput--;
if (vp->v_numoutput < 0)
panic("vwakeup: neg numoutput");
if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
vp->v_flag &= ~VBWAIT;
wakeup((caddr_t) &vp->v_numoutput);
}
}
}
/*
* Flush out and invalidate all buffers associated with a vnode.
* Called with the underlying object locked.
*/
int
vinvalbuf(vp, flags, cred, td, slpflag, slptimeo)
register struct vnode *vp;
int flags;
struct ucred *cred;
struct thread *td;
int slpflag, slptimeo;
{
register struct buf *bp;
struct buf *nbp, *blist;
int s, error;
vm_object_t object;
GIANT_REQUIRED;
if (flags & V_SAVE) {
s = splbio();
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
error = tsleep((caddr_t)&vp->v_numoutput,
slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo);
if (error) {
splx(s);
return (error);
}
}
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
splx(s);
if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0)
return (error);
s = splbio();
if (vp->v_numoutput > 0 ||
!TAILQ_EMPTY(&vp->v_dirtyblkhd))
panic("vinvalbuf: dirty bufs");
}
splx(s);
}
s = splbio();
for (;;) {
blist = TAILQ_FIRST(&vp->v_cleanblkhd);
if (!blist)
blist = TAILQ_FIRST(&vp->v_dirtyblkhd);
if (!blist)
break;
for (bp = blist; bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
error = BUF_TIMELOCK(bp,
LK_EXCLUSIVE | LK_SLEEPFAIL,
"vinvalbuf", slpflag, slptimeo);
if (error == ENOLCK)
break;
splx(s);
return (error);
}
/*
* XXX Since there are no node locks for NFS, I
* believe there is a slight chance that a delayed
* write will occur while sleeping just above, so
* check for it. Note that vfs_bio_awrite expects
* buffers to reside on a queue, while BUF_WRITE and
* brelse do not.
*/
if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
(flags & V_SAVE)) {
if (bp->b_vp == vp) {
if (bp->b_flags & B_CLUSTEROK) {
BUF_UNLOCK(bp);
vfs_bio_awrite(bp);
} else {
bremfree(bp);
bp->b_flags |= B_ASYNC;
BUF_WRITE(bp);
}
} else {
bremfree(bp);
(void) BUF_WRITE(bp);
}
break;
}
bremfree(bp);
bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
}
}
/*
* Wait for I/O to complete. XXX needs cleaning up. The vnode can
* have write I/O in-progress but if there is a VM object then the
* VM object can also have read-I/O in-progress.
*/
do {
while (vp->v_numoutput > 0) {
vp->v_flag |= VBWAIT;
tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0);
}
if (VOP_GETVOBJECT(vp, &object) == 0) {
while (object->paging_in_progress)
vm_object_pip_sleep(object, "vnvlbx");
}
} while (vp->v_numoutput > 0);
splx(s);
/*
* Destroy the copy in the VM cache, too.
*/
mtx_lock(&vp->v_interlock);
if (VOP_GETVOBJECT(vp, &object) == 0) {
vm_object_page_remove(object, 0, 0,
(flags & V_SAVE) ? TRUE : FALSE);
}
mtx_unlock(&vp->v_interlock);
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd))
panic("vinvalbuf: flush failed");
return (0);
}
/*
* Truncate a file's buffer and pages to a specified length. This
* is in lieu of the old vinvalbuf mechanism, which performed unneeded
* sync activity.
*/
int
vtruncbuf(vp, cred, td, length, blksize)
register struct vnode *vp;
struct ucred *cred;
struct thread *td;
off_t length;
int blksize;
{
register struct buf *bp;
struct buf *nbp;
int s, anyfreed;
int trunclbn;
/*
* Round up to the *next* lbn.
*/
trunclbn = (length + blksize - 1) / blksize;
s = splbio();
restart:
anyfreed = 1;
for (;anyfreed;) {
anyfreed = 0;
for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (bp->b_lblkno >= trunclbn) {
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
goto restart;
} else {
bremfree(bp);
bp->b_flags |= (B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
}
if (nbp &&
(((nbp->b_xflags & BX_VNCLEAN) == 0) ||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI))) {
goto restart;
}
}
}
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (bp->b_lblkno >= trunclbn) {
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
goto restart;
} else {
bremfree(bp);
bp->b_flags |= (B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
}
if (nbp &&
(((nbp->b_xflags & BX_VNDIRTY) == 0) ||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI) == 0)) {
goto restart;
}
}
}
}
if (length > 0) {
restartsync:
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) {
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
goto restart;
} else {
bremfree(bp);
if (bp->b_vp == vp) {
bp->b_flags |= B_ASYNC;
} else {
bp->b_flags &= ~B_ASYNC;
}
BUF_WRITE(bp);
}
goto restartsync;
}
}
}
while (vp->v_numoutput > 0) {
vp->v_flag |= VBWAIT;
tsleep(&vp->v_numoutput, PVM, "vbtrunc", 0);
}
splx(s);
vnode_pager_setsize(vp, length);
return (0);
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
int s;
KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
vhold(vp);
bp->b_vp = vp;
bp->b_dev = vn_todev(vp);
/*
* Insert onto list for new vnode.
*/
s = splbio();
bp->b_xflags |= BX_VNCLEAN;
bp->b_xflags &= ~BX_VNDIRTY;
TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs);
splx(s);
}
/*
* Disassociate a buffer from a vnode.
*/
void
brelvp(bp)
register struct buf *bp;
{
struct vnode *vp;
struct buflists *listheadp;
int s;
KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
/*
* Delete from old vnode list, if on one.
*/
vp = bp->b_vp;
s = splbio();
if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
if (bp->b_xflags & BX_VNDIRTY)
listheadp = &vp->v_dirtyblkhd;
else
listheadp = &vp->v_cleanblkhd;
TAILQ_REMOVE(listheadp, bp, b_vnbufs);
bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
}
if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
vp->v_flag &= ~VONWORKLST;
LIST_REMOVE(vp, v_synclist);
}
splx(s);
bp->b_vp = (struct vnode *) 0;
vdrop(vp);
}
/*
* Add an item to the syncer work queue.
*/
static void
vn_syncer_add_to_worklist(struct vnode *vp, int delay)
{
int s, slot;
s = splbio();
if (vp->v_flag & VONWORKLST) {
LIST_REMOVE(vp, v_synclist);
}
if (delay > syncer_maxdelay - 2)
delay = syncer_maxdelay - 2;
slot = (syncer_delayno + delay) & syncer_mask;
LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist);
vp->v_flag |= VONWORKLST;
splx(s);
}
struct proc *updateproc;
static void sched_sync __P((void));
static struct kproc_desc up_kp = {
"syncer",
sched_sync,
&updateproc
};
SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
/*
* System filesystem synchronizer daemon.
*/
void
sched_sync(void)
{
struct synclist *slp;
struct vnode *vp;
struct mount *mp;
long starttime;
int s;
struct thread *td = &updateproc->p_thread; /* XXXKSE */
mtx_lock(&Giant);
EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc,
SHUTDOWN_PRI_LAST);
for (;;) {
kthread_suspend_check(td->td_proc);
starttime = time_second;
/*
* Push files whose dirty time has expired. Be careful
* of interrupt race on slp queue.
*/
s = splbio();
slp = &syncer_workitem_pending[syncer_delayno];
syncer_delayno += 1;
if (syncer_delayno == syncer_maxdelay)
syncer_delayno = 0;
splx(s);
while ((vp = LIST_FIRST(slp)) != NULL) {
if (VOP_ISLOCKED(vp, NULL) == 0 &&
vn_start_write(vp, &mp, V_NOWAIT) == 0) {
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
(void) VOP_FSYNC(vp, td->td_proc->p_ucred, MNT_LAZY, td);
VOP_UNLOCK(vp, 0, td);
vn_finished_write(mp);
}
s = splbio();
if (LIST_FIRST(slp) == vp) {
/*
* Note: v_tag VT_VFS vps can remain on the
* worklist too with no dirty blocks, but
* since sync_fsync() moves it to a different
* slot we are safe.
*/
if (TAILQ_EMPTY(&vp->v_dirtyblkhd) &&
!vn_isdisk(vp, NULL))
panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag);
/*
* Put us back on the worklist. The worklist
* routine will remove us from our current
* position and then add us back in at a later
* position.
*/
vn_syncer_add_to_worklist(vp, syncdelay);
}
splx(s);
}
/*
* Do soft update processing.
*/
#ifdef SOFTUPDATES
softdep_process_worklist(NULL);
#endif
/*
* The variable rushjob allows the kernel to speed up the
* processing of the filesystem syncer process. A rushjob
* value of N tells the filesystem syncer to process the next
* N seconds worth of work on its queue ASAP. Currently rushjob
* is used by the soft update code to speed up the filesystem
* syncer process when the incore state is getting so far
* ahead of the disk that the kernel memory pool is being
* threatened with exhaustion.
*/
if (rushjob > 0) {
rushjob -= 1;
continue;
}
/*
* If it has taken us less than a second to process the
* current work, then wait. Otherwise start right over
* again. We can still lose time if any single round
* takes more than two seconds, but it does not really
* matter as we are just trying to generally pace the
* filesystem activity.
*/
if (time_second == starttime)
tsleep(&lbolt, PPAUSE, "syncer", 0);
}
}
/*
* Request the syncer daemon to speed up its work.
* We never push it to speed up more than half of its
* normal turn time, otherwise it could take over the cpu.
* XXXKSE only one update?
*/
int
speedup_syncer()
{
mtx_lock_spin(&sched_lock);
if (updateproc->p_thread.td_wchan == &lbolt) /* XXXKSE */
setrunnable(&updateproc->p_thread);
mtx_unlock_spin(&sched_lock);
if (rushjob < syncdelay / 2) {
rushjob += 1;
stat_rush_requests += 1;
return (1);
}
return(0);
}
/*
* Associate a p-buffer with a vnode.
*
* Also sets B_PAGING flag to indicate that vnode is not fully associated
* with the buffer. i.e. the bp has not been linked into the vnode or
* ref-counted.
*/
void
pbgetvp(vp, bp)
register struct vnode *vp;
register struct buf *bp;
{
KASSERT(bp->b_vp == NULL, ("pbgetvp: not free"));
bp->b_vp = vp;
bp->b_flags |= B_PAGING;
bp->b_dev = vn_todev(vp);
}
/*
* Disassociate a p-buffer from a vnode.
*/
void
pbrelvp(bp)
register struct buf *bp;
{
KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
/* XXX REMOVE ME */
if (TAILQ_NEXT(bp, b_vnbufs) != NULL) {
panic(
"relpbuf(): b_vp was probably reassignbuf()d %p %x",
bp,
(int)bp->b_flags
);
}
bp->b_vp = (struct vnode *) 0;
bp->b_flags &= ~B_PAGING;
}
/*
* Change the vnode a pager buffer is associated with.
*/
void
pbreassignbuf(bp, newvp)
struct buf *bp;
struct vnode *newvp;
{
KASSERT(bp->b_flags & B_PAGING,
("pbreassignbuf() on non phys bp %p", bp));
bp->b_vp = newvp;
}
/*
* Reassign a buffer from one vnode to another.
* Used to assign file specific control information
* (indirect blocks) to the vnode to which they belong.
*/
void
reassignbuf(bp, newvp)
register struct buf *bp;
register struct vnode *newvp;
{
struct buflists *listheadp;
int delay;
int s;
if (newvp == NULL) {
printf("reassignbuf: NULL");
return;
}
++reassignbufcalls;
/*
* B_PAGING flagged buffers cannot be reassigned because their vp
* is not fully linked in.
*/
if (bp->b_flags & B_PAGING)
panic("cannot reassign paging buffer");
s = splbio();
/*
* Delete from old vnode list, if on one.
*/
if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
if (bp->b_xflags & BX_VNDIRTY)
listheadp = &bp->b_vp->v_dirtyblkhd;
else
listheadp = &bp->b_vp->v_cleanblkhd;
TAILQ_REMOVE(listheadp, bp, b_vnbufs);
bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
if (bp->b_vp != newvp) {
vdrop(bp->b_vp);
bp->b_vp = NULL; /* for clarification */
}
}
/*
* If dirty, put on list of dirty buffers; otherwise insert onto list
* of clean buffers.
*/
if (bp->b_flags & B_DELWRI) {
struct buf *tbp;
listheadp = &newvp->v_dirtyblkhd;
if ((newvp->v_flag & VONWORKLST) == 0) {
switch (newvp->v_type) {
case VDIR:
delay = dirdelay;
break;
case VCHR:
if (newvp->v_rdev->si_mountpoint != NULL) {
delay = metadelay;
break;
}
/* fall through */
default:
delay = filedelay;
}
vn_syncer_add_to_worklist(newvp, delay);
}
bp->b_xflags |= BX_VNDIRTY;
tbp = TAILQ_FIRST(listheadp);
if (tbp == NULL ||
bp->b_lblkno == 0 ||
(bp->b_lblkno > 0 && tbp->b_lblkno < 0) ||
(bp->b_lblkno > 0 && bp->b_lblkno < tbp->b_lblkno)) {
TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs);
++reassignbufsortgood;
} else if (bp->b_lblkno < 0) {
TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs);
++reassignbufsortgood;
} else if (reassignbufmethod == 1) {
/*
* New sorting algorithm, only handle sequential case,
* otherwise append to end (but before metadata)
*/
if ((tbp = gbincore(newvp, bp->b_lblkno - 1)) != NULL &&
(tbp->b_xflags & BX_VNDIRTY)) {
/*
* Found the best place to insert the buffer
*/
TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
++reassignbufsortgood;
} else {
/*
* Missed, append to end, but before meta-data.
* We know that the head buffer in the list is
* not meta-data due to prior conditionals.
*
* Indirect effects: NFS second stage write
* tends to wind up here, giving maximum
* distance between the unstable write and the
* commit rpc.
*/
tbp = TAILQ_LAST(listheadp, buflists);
while (tbp && tbp->b_lblkno < 0)
tbp = TAILQ_PREV(tbp, buflists, b_vnbufs);
TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
++reassignbufsortbad;
}
} else {
/*
* Old sorting algorithm, scan queue and insert
*/
struct buf *ttbp;
while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) &&
(ttbp->b_lblkno < bp->b_lblkno)) {
++reassignbufloops;
tbp = ttbp;
}
TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
}
} else {
bp->b_xflags |= BX_VNCLEAN;
TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs);
if ((newvp->v_flag & VONWORKLST) &&
TAILQ_EMPTY(&newvp->v_dirtyblkhd)) {
newvp->v_flag &= ~VONWORKLST;
LIST_REMOVE(newvp, v_synclist);
}
}
if (bp->b_vp != newvp) {
bp->b_vp = newvp;
vhold(bp->b_vp);
}
splx(s);
}
/*
* Create a vnode for a device.
* Used for mounting the root file system.
*/
int
bdevvp(dev, vpp)
dev_t dev;
struct vnode **vpp;
{
register struct vnode *vp;
struct vnode *nvp;
int error;
if (dev == NODEV) {
*vpp = NULLVP;
return (ENXIO);
}
if (vfinddev(dev, VCHR, vpp))
return (0);
error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp);
if (error) {
*vpp = NULLVP;
return (error);
}
vp = nvp;
vp->v_type = VCHR;
addalias(vp, dev);
*vpp = vp;
return (0);
}
/*
* Add vnode to the alias list hung off the dev_t.
*
* The reason for this gunk is that multiple vnodes can reference
* the same physical device, so checking vp->v_usecount to see
* how many users there are is inadequate; the v_usecount for
* the vnodes need to be accumulated. vcount() does that.
*/
struct vnode *
addaliasu(nvp, nvp_rdev)
struct vnode *nvp;
udev_t nvp_rdev;
{
struct vnode *ovp;
vop_t **ops;
dev_t dev;
if (nvp->v_type == VBLK)
return (nvp);
if (nvp->v_type != VCHR)
panic("addaliasu on non-special vnode");
dev = udev2dev(nvp_rdev, 0);
/*
* Check to see if we have a bdevvp vnode with no associated
* filesystem. If so, we want to associate the filesystem of
* the new newly instigated vnode with the bdevvp vnode and
* discard the newly created vnode rather than leaving the
* bdevvp vnode lying around with no associated filesystem.
*/
if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) {
addalias(nvp, dev);
return (nvp);
}
/*
* Discard unneeded vnode, but save its node specific data.
* Note that if there is a lock, it is carried over in the
* node specific data to the replacement vnode.
*/
vref(ovp);
ovp->v_data = nvp->v_data;
ovp->v_tag = nvp->v_tag;
nvp->v_data = NULL;
lockinit(&ovp->v_lock, PVFS, nvp->v_lock.lk_wmesg,
nvp->v_lock.lk_timo, nvp->v_lock.lk_flags & LK_EXTFLG_MASK);
if (nvp->v_vnlock)
ovp->v_vnlock = &ovp->v_lock;
ops = ovp->v_op;
ovp->v_op = nvp->v_op;
if (VOP_ISLOCKED(nvp, curthread)) {
VOP_UNLOCK(nvp, 0, curthread);
vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread);
}
nvp->v_op = ops;
insmntque(ovp, nvp->v_mount);
vrele(nvp);
vgone(nvp);
return (ovp);
}
/* This is a local helper function that do the same as addaliasu, but for a
* dev_t instead of an udev_t. */
static void
addalias(nvp, dev)
struct vnode *nvp;
dev_t dev;
{
KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode"));
nvp->v_rdev = dev;
mtx_lock(&spechash_mtx);
SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext);
mtx_unlock(&spechash_mtx);
}
/*
* Grab a particular vnode from the free list, increment its
* reference count and lock it. The vnode lock bit is set if the
* vnode is being eliminated in vgone. The process is awakened
* when the transition is completed, and an error returned to
* indicate that the vnode is no longer usable (possibly having
* been changed to a new file system type).
*/
int
vget(vp, flags, td)
register struct vnode *vp;
int flags;
struct thread *td;
{
int error;
/*
* If the vnode is in the process of being cleaned out for
* another use, we wait for the cleaning to finish and then
* return failure. Cleaning is determined by checking that
* the VXLOCK flag is set.
*/
if ((flags & LK_INTERLOCK) == 0)
mtx_lock(&vp->v_interlock);
if (vp->v_flag & VXLOCK) {
if (vp->v_vxproc == curthread) {
printf("VXLOCK interlock avoided\n");
} else {
vp->v_flag |= VXWANT;
msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP,
"vget", 0);
return (ENOENT);
}
}
vp->v_usecount++;
if (VSHOULDBUSY(vp))
vbusy(vp);
if (flags & LK_TYPE_MASK) {
if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
/*
* must expand vrele here because we do not want
* to call VOP_INACTIVE if the reference count
* drops back to zero since it was never really
* active. We must remove it from the free list
* before sleeping so that multiple processes do
* not try to recycle it.
*/
mtx_lock(&vp->v_interlock);
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
mtx_unlock(&vp->v_interlock);
}
return (error);
}
mtx_unlock(&vp->v_interlock);
return (0);
}
/*
* Increase the reference count of a vnode.
*/
void
vref(struct vnode *vp)
{
mtx_lock(&vp->v_interlock);
vp->v_usecount++;
mtx_unlock(&vp->v_interlock);
}
/*
* Vnode put/release.
* If count drops to zero, call inactive routine and return to freelist.
*/
void
vrele(vp)
struct vnode *vp;
{
struct thread *td = curthread; /* XXX */
KASSERT(vp != NULL, ("vrele: null vp"));
mtx_lock(&vp->v_interlock);
/* Skip this v_writecount check if we're going to panic below. */
KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1,
("vrele: missed vn_close"));
if (vp->v_usecount > 1) {
vp->v_usecount--;
mtx_unlock(&vp->v_interlock);
return;
}
if (vp->v_usecount == 1) {
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
/*
* If we are doing a vput, the node is already locked, and we must
* call VOP_INACTIVE with the node locked. So, in the case of
* vrele, we explicitly lock the vnode before calling VOP_INACTIVE.
*/
if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) {
VOP_INACTIVE(vp, td);
}
} else {
#ifdef DIAGNOSTIC
vprint("vrele: negative ref count", vp);
mtx_unlock(&vp->v_interlock);
#endif
panic("vrele: negative ref cnt");
}
}
/*
* Release an already locked vnode. This give the same effects as
* unlock+vrele(), but takes less time and avoids releasing and
* re-aquiring the lock (as vrele() aquires the lock internally.)
*/
void
vput(vp)
struct vnode *vp;
{
struct thread *td = curthread; /* XXX */
GIANT_REQUIRED;
KASSERT(vp != NULL, ("vput: null vp"));
mtx_lock(&vp->v_interlock);
/* Skip this v_writecount check if we're going to panic below. */
KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1,
("vput: missed vn_close"));
if (vp->v_usecount > 1) {
vp->v_usecount--;
VOP_UNLOCK(vp, LK_INTERLOCK, td);
return;
}
if (vp->v_usecount == 1) {
vp->v_usecount--;
if (VSHOULDFREE(vp))
vfree(vp);
/*
* If we are doing a vput, the node is already locked, and we must
* call VOP_INACTIVE with the node locked. So, in the case of
* vrele, we explicitly lock the vnode before calling VOP_INACTIVE.
*/
mtx_unlock(&vp->v_interlock);
VOP_INACTIVE(vp, td);
} else {
#ifdef DIAGNOSTIC
vprint("vput: negative ref count", vp);
#endif
panic("vput: negative ref cnt");
}
}
/*
* Somebody doesn't want the vnode recycled.
*/
void
vhold(vp)
register struct vnode *vp;
{
int s;
s = splbio();
vp->v_holdcnt++;
if (VSHOULDBUSY(vp))
vbusy(vp);
splx(s);
}
/*
* Note that there is one less who cares about this vnode. vdrop() is the
* opposite of vhold().
*/
void
vdrop(vp)
register struct vnode *vp;
{
int s;
s = splbio();
if (vp->v_holdcnt <= 0)
panic("vdrop: holdcnt");
vp->v_holdcnt--;
if (VSHOULDFREE(vp))
vfree(vp);
splx(s);
}
/*
* Remove any vnodes in the vnode table belonging to mount point mp.
*
* If 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 VSYSTEM to be skipped.
*
* `rootrefs' specifies the base reference count for the root vnode
* of this filesystem. The root vnode is considered busy if its
* v_usecount exceeds this value. On a successful return, vflush()
* will call vrele() on the root vnode exactly rootrefs times.
* If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
* be zero.
*/
#ifdef DIAGNOSTIC
static int busyprt = 0; /* print out busy vnodes */
SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
#endif
int
vflush(mp, rootrefs, flags)
struct mount *mp;
int rootrefs;
int flags;
{
struct thread *td = curthread; /* XXX */
struct vnode *vp, *nvp, *rootvp = NULL;
int busy = 0, error;
if (rootrefs > 0) {
KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
("vflush: bad args"));
/*
* Get the filesystem root vnode. We can vput() it
* immediately, since with rootrefs > 0, it won't go away.
*/
if ((error = VFS_ROOT(mp, &rootvp)) != 0)
return (error);
vput(rootvp);
}
mtx_lock(&mntvnode_mtx);
loop:
for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
/*
* Make sure this vnode wasn't reclaimed in getnewvnode().
* Start over if it has (it won't be on the list anymore).
*/
if (vp->v_mount != mp)
goto loop;
nvp = TAILQ_NEXT(vp, v_nmntvnodes);
mtx_unlock(&mntvnode_mtx);
mtx_lock(&vp->v_interlock);
/*
* Skip over a vnodes marked VSYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
mtx_unlock(&vp->v_interlock);
mtx_lock(&mntvnode_mtx);
continue;
}
/*
* If WRITECLOSE is set, only flush out regular file vnodes
* open for writing.
*/
if ((flags & WRITECLOSE) &&
(vp->v_writecount == 0 || vp->v_type != VREG)) {
mtx_unlock(&vp->v_interlock);
mtx_lock(&mntvnode_mtx);
continue;
}
/*
* With v_usecount == 0, all we need to do is clear out the
* vnode data structures and we are done.
*/
if (vp->v_usecount == 0) {
vgonel(vp, td);
mtx_lock(&mntvnode_mtx);
continue;
}
/*
* If FORCECLOSE is set, forcibly close the vnode. For block
* or character devices, revert to an anonymous device. For
* all other files, just kill them.
*/
if (flags & FORCECLOSE) {
if (vp->v_type != VCHR) {
vgonel(vp, td);
} else {
vclean(vp, 0, td);
vp->v_op = spec_vnodeop_p;
insmntque(vp, (struct mount *) 0);
}
mtx_lock(&mntvnode_mtx);
continue;
}
#ifdef DIAGNOSTIC
if (busyprt)
vprint("vflush: busy vnode", vp);
#endif
mtx_unlock(&vp->v_interlock);
mtx_lock(&mntvnode_mtx);
busy++;
}
mtx_unlock(&mntvnode_mtx);
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.
*/
mtx_lock(&rootvp->v_interlock);
KASSERT(busy > 0, ("vflush: not busy"));
KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs"));
if (busy == 1 && rootvp->v_usecount == rootrefs) {
vgonel(rootvp, td);
busy = 0;
} else
mtx_unlock(&rootvp->v_interlock);
}
if (busy)
return (EBUSY);
for (; rootrefs > 0; rootrefs--)
vrele(rootvp);
return (0);
}
/*
* Disassociate the underlying file system from a vnode.
*/
static void
vclean(vp, flags, td)
struct vnode *vp;
int flags;
struct thread *td;
{
int active;
/*
* Check to see if the vnode is in use. If so we have to reference it
* before we clean it out so that its count cannot fall to zero and
* generate a race against ourselves to recycle it.
*/
if ((active = vp->v_usecount))
vp->v_usecount++;
/*
* Prevent the vnode from being recycled or brought into use while we
* clean it out.
*/
if (vp->v_flag & VXLOCK)
panic("vclean: deadlock");
vp->v_flag |= VXLOCK;
vp->v_vxproc = curthread;
/*
* Even if the count is zero, the VOP_INACTIVE routine may still
* have the object locked while it cleans it out. The VOP_LOCK
* ensures that the VOP_INACTIVE routine is done with its work.
* For active vnodes, it ensures that no other activity can
* occur while the underlying object is being cleaned out.
*/
VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td);
/*
* Clean out any buffers associated with the vnode.
* If the flush fails, just toss the buffers.
*/
if (flags & DOCLOSE) {
if (TAILQ_FIRST(&vp->v_dirtyblkhd) != NULL)
(void) vn_write_suspend_wait(vp, NULL, V_WAIT);
if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0)
vinvalbuf(vp, 0, NOCRED, td, 0, 0);
}
VOP_DESTROYVOBJECT(vp);
/*
* If purging an active vnode, it must be closed and
* deactivated before being reclaimed. Note that the
* VOP_INACTIVE will unlock the vnode.
*/
if (active) {
if (flags & DOCLOSE)
VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
VOP_INACTIVE(vp, td);
} else {
/*
* Any other processes trying to obtain this lock must first
* wait for VXLOCK to clear, then call the new lock operation.
*/
VOP_UNLOCK(vp, 0, td);
}
/*
* Reclaim the vnode.
*/
if (VOP_RECLAIM(vp, td))
panic("vclean: cannot reclaim");
if (active) {
/*
* Inline copy of vrele() since VOP_INACTIVE
* has already been called.
*/
mtx_lock(&vp->v_interlock);
if (--vp->v_usecount <= 0) {
#ifdef DIAGNOSTIC
if (vp->v_usecount < 0 || vp->v_writecount != 0) {
vprint("vclean: bad ref count", vp);
panic("vclean: ref cnt");
}
#endif
vfree(vp);
}
mtx_unlock(&vp->v_interlock);
}
cache_purge(vp);
vp->v_vnlock = NULL;
lockdestroy(&vp->v_lock);
if (VSHOULDFREE(vp))
vfree(vp);
/*
* Done with purge, notify sleepers of the grim news.
*/
vp->v_op = dead_vnodeop_p;
vn_pollgone(vp);
vp->v_tag = VT_NON;
vp->v_flag &= ~VXLOCK;
vp->v_vxproc = NULL;
if (vp->v_flag & VXWANT) {
vp->v_flag &= ~VXWANT;
wakeup((caddr_t) vp);
}
}
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
vop_revoke(ap)
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap;
{
struct vnode *vp, *vq;
dev_t dev;
KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke"));
vp = ap->a_vp;
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP,
"vop_revokeall", 0);
return (0);
}
dev = vp->v_rdev;
for (;;) {
mtx_lock(&spechash_mtx);
vq = SLIST_FIRST(&dev->si_hlist);
mtx_unlock(&spechash_mtx);
if (!vq)
break;
vgone(vq);
}
return (0);
}
/*
* Recycle an unused vnode to the front of the free list.
* Release the passed interlock if the vnode will be recycled.
*/
int
vrecycle(vp, inter_lkp, td)
struct vnode *vp;
struct mtx *inter_lkp;
struct thread *td;
{
mtx_lock(&vp->v_interlock);
if (vp->v_usecount == 0) {
if (inter_lkp) {
mtx_unlock(inter_lkp);
}
vgonel(vp, td);
return (1);
}
mtx_unlock(&vp->v_interlock);
return (0);
}
/*
* Eliminate all activity associated with a vnode
* in preparation for reuse.
*/
void
vgone(vp)
register struct vnode *vp;
{
struct thread *td = curthread; /* XXX */
mtx_lock(&vp->v_interlock);
vgonel(vp, td);
}
/*
* vgone, with the vp interlock held.
*/
void
vgonel(vp, td)
struct vnode *vp;
struct thread *td;
{
int s;
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
msleep((caddr_t)vp, &vp->v_interlock, PINOD | PDROP,
"vgone", 0);
return;
}
/*
* Clean out the filesystem specific data.
*/
vclean(vp, DOCLOSE, td);
mtx_lock(&vp->v_interlock);
/*
* Delete from old mount point vnode list, if on one.
*/
if (vp->v_mount != NULL)
insmntque(vp, (struct mount *)0);
/*
* If special device, remove it from special device alias list
* if it is on one.
*/
if (vp->v_type == VCHR && vp->v_rdev != NULL && vp->v_rdev != NODEV) {
mtx_lock(&spechash_mtx);
SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext);
freedev(vp->v_rdev);
mtx_unlock(&spechash_mtx);
vp->v_rdev = NULL;
}
/*
* If it is on the freelist and not already at the head,
* move it to the head of the list. The test of the
* VDOOMED flag and the reference count of zero is because
* it will be removed from the free list by getnewvnode,
* but will not have its reference count incremented until
* after calling vgone. If the reference count were
* incremented first, vgone would (incorrectly) try to
* close the previous instance of the underlying object.
*/
if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) {
s = splbio();
mtx_lock(&vnode_free_list_mtx);
if (vp->v_flag & VFREE)
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
else
freevnodes++;
vp->v_flag |= VFREE;
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
mtx_unlock(&vnode_free_list_mtx);
splx(s);
}
vp->v_type = VBAD;
mtx_unlock(&vp->v_interlock);
}
/*
* Lookup a vnode by device number.
*/
int
vfinddev(dev, type, vpp)
dev_t dev;
enum vtype type;
struct vnode **vpp;
{
struct vnode *vp;
mtx_lock(&spechash_mtx);
SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) {
if (type == vp->v_type) {
*vpp = vp;
mtx_unlock(&spechash_mtx);
return (1);
}
}
mtx_unlock(&spechash_mtx);
return (0);
}
/*
* Calculate the total number of references to a special device.
*/
int
vcount(vp)
struct vnode *vp;
{
struct vnode *vq;
int count;
count = 0;
mtx_lock(&spechash_mtx);
SLIST_FOREACH(vq, &vp->v_rdev->si_hlist, v_specnext)
count += vq->v_usecount;
mtx_unlock(&spechash_mtx);
return (count);
}
/*
* Same as above, but using the dev_t as argument
*/
int
count_dev(dev)
dev_t dev;
{
struct vnode *vp;
vp = SLIST_FIRST(&dev->si_hlist);
if (vp == NULL)
return (0);
return(vcount(vp));
}
/*
* Print out a description of a vnode.
*/
static char *typename[] =
{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
void
vprint(label, vp)
char *label;
struct vnode *vp;
{
char buf[96];
if (label != NULL)
printf("%s: %p: ", label, (void *)vp);
else
printf("%p: ", (void *)vp);
printf("type %s, usecount %d, writecount %d, refcount %d,",
typename[vp->v_type], vp->v_usecount, vp->v_writecount,
vp->v_holdcnt);
buf[0] = '\0';
if (vp->v_flag & VROOT)
strcat(buf, "|VROOT");
if (vp->v_flag & VTEXT)
strcat(buf, "|VTEXT");
if (vp->v_flag & VSYSTEM)
strcat(buf, "|VSYSTEM");
if (vp->v_flag & VXLOCK)
strcat(buf, "|VXLOCK");
if (vp->v_flag & VXWANT)
strcat(buf, "|VXWANT");
if (vp->v_flag & VBWAIT)
strcat(buf, "|VBWAIT");
if (vp->v_flag & VDOOMED)
strcat(buf, "|VDOOMED");
if (vp->v_flag & VFREE)
strcat(buf, "|VFREE");
if (vp->v_flag & VOBJBUF)
strcat(buf, "|VOBJBUF");
if (buf[0] != '\0')
printf(" flags (%s)", &buf[1]);
if (vp->v_data == NULL) {
printf("\n");
} else {
printf("\n\t");
VOP_PRINT(vp);
}
}
#ifdef DDB
#include <ddb/ddb.h>
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
{
struct thread *td = curthread; /* XXX */
struct mount *mp, *nmp;
struct vnode *vp;
printf("Locked vnodes\n");
mtx_lock(&mountlist_mtx);
for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
nmp = TAILQ_NEXT(mp, mnt_list);
continue;
}
mtx_lock(&mntvnode_mtx);
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
if (VOP_ISLOCKED(vp, NULL))
vprint((char *)0, vp);
}
mtx_unlock(&mntvnode_mtx);
mtx_lock(&mountlist_mtx);
nmp = TAILQ_NEXT(mp, mnt_list);
vfs_unbusy(mp, td);
}
mtx_unlock(&mountlist_mtx);
}
#endif
/*
* Top level filesystem related information gathering.
*/
static int sysctl_ovfs_conf __P((SYSCTL_HANDLER_ARGS));
static int
vfs_sysctl(SYSCTL_HANDLER_ARGS)
{
int *name = (int *)arg1 - 1; /* XXX */
u_int namelen = arg2 + 1; /* XXX */
struct vfsconf *vfsp;
#if 1 || defined(COMPAT_PRELITE2)
/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
if (namelen == 1)
return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
#endif
/* XXX the below code does not compile; vfs_sysctl does not exist. */
#ifdef notyet
/* all sysctl names at this level are at least name and field */
if (namelen < 2)
return (ENOTDIR); /* overloaded */
if (name[0] != VFS_GENERIC) {
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[0])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
oldp, oldlenp, newp, newlen, td));
}
#endif
switch (name[1]) {
case VFS_MAXTYPENUM:
if (namelen != 2)
return (ENOTDIR);
return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
case VFS_CONF:
if (namelen != 3)
return (ENOTDIR); /* overloaded */
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
if (vfsp->vfc_typenum == name[2])
break;
if (vfsp == NULL)
return (EOPNOTSUPP);
return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
}
return (EOPNOTSUPP);
}
SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
"Generic filesystem");
#if 1 || defined(COMPAT_PRELITE2)
static int
sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
{
int error;
struct vfsconf *vfsp;
struct ovfsconf ovfs;
for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
strcpy(ovfs.vfc_name, vfsp->vfc_name);
ovfs.vfc_index = vfsp->vfc_typenum;
ovfs.vfc_refcount = vfsp->vfc_refcount;
ovfs.vfc_flags = vfsp->vfc_flags;
error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
if (error)
return error;
}
return 0;
}
#endif /* 1 || COMPAT_PRELITE2 */
#if COMPILING_LINT
#define KINFO_VNODESLOP 10
/*
* Dump vnode list (via sysctl).
* Copyout address of vnode followed by vnode.
*/
/* ARGSUSED */
static int
sysctl_vnode(SYSCTL_HANDLER_ARGS)
{
struct thread *td = curthread; /* XXX */
struct mount *mp, *nmp;
struct vnode *nvp, *vp;
int error;
#define VPTRSZ sizeof (struct vnode *)
#define VNODESZ sizeof (struct vnode)
req->lock = 0;
if (!req->oldptr) /* Make an estimate */
return (SYSCTL_OUT(req, 0,
(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
mtx_lock(&mountlist_mtx);
for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) {
nmp = TAILQ_NEXT(mp, mnt_list);
continue;
}
mtx_lock(&mntvnode_mtx);
again:
for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
vp != NULL;
vp = nvp) {
/*
* Check that the vp is still associated with
* this filesystem. RACE: could have been
* recycled onto the same filesystem.
*/
if (vp->v_mount != mp)
goto again;
nvp = TAILQ_NEXT(vp, v_nmntvnodes);
mtx_unlock(&mntvnode_mtx);
if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
(error = SYSCTL_OUT(req, vp, VNODESZ)))
return (error);
mtx_lock(&mntvnode_mtx);
}
mtx_unlock(&mntvnode_mtx);
mtx_lock(&mountlist_mtx);
nmp = TAILQ_NEXT(mp, mnt_list);
vfs_unbusy(mp, td);
}
mtx_unlock(&mountlist_mtx);
return (0);
}
/*
* XXX
* Exporting the vnode list on large systems causes them to crash.
* Exporting the vnode list on medium systems causes sysctl to coredump.
*/
SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
0, 0, sysctl_vnode, "S,vnode", "");
#endif
/*
* Check to see if a filesystem is mounted on a block device.
*/
int
vfs_mountedon(vp)
struct vnode *vp;
{
if (vp->v_rdev->si_mountpoint != NULL)
return (EBUSY);
return (0);
}
/*
* Unmount all filesystems. The list is traversed in reverse order
* of mounting to avoid dependencies.
*/
void
vfs_unmountall()
{
struct mount *mp;
struct thread *td;
int error;
if (curthread != NULL)
td = curthread;
else
td = &initproc->p_thread; /* XXX XXX should this be proc0? */
/*
* Since this only runs when rebooting, it is not interlocked.
*/
while(!TAILQ_EMPTY(&mountlist)) {
mp = TAILQ_LAST(&mountlist, mntlist);
error = dounmount(mp, MNT_FORCE, td);
if (error) {
TAILQ_REMOVE(&mountlist, mp, mnt_list);
printf("unmount of %s failed (",
mp->mnt_stat.f_mntonname);
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
} else {
/* The unmount has removed mp from the mountlist */
}
}
}
/*
* perform msync on all vnodes under a mount point
* the mount point must be locked.
*/
void
vfs_msync(struct mount *mp, int flags)
{
struct vnode *vp, *nvp;
struct vm_object *obj;
int tries;
GIANT_REQUIRED;
tries = 5;
mtx_lock(&mntvnode_mtx);
loop:
for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
if (vp->v_mount != mp) {
if (--tries > 0)
goto loop;
break;
}
nvp = TAILQ_NEXT(vp, v_nmntvnodes);
if (vp->v_flag & VXLOCK) /* XXX: what if MNT_WAIT? */
continue;
if (vp->v_flag & VNOSYNC) /* unlinked, skip it */
continue;
if ((vp->v_flag & VOBJDIRTY) &&
(flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
mtx_unlock(&mntvnode_mtx);
if (!vget(vp,
LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, curthread)) {
if (VOP_GETVOBJECT(vp, &obj) == 0) {
vm_object_page_clean(obj, 0, 0,
flags == MNT_WAIT ?
OBJPC_SYNC : OBJPC_NOSYNC);
}
vput(vp);
}
mtx_lock(&mntvnode_mtx);
if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) {
if (--tries > 0)
goto loop;
break;
}
}
}
mtx_unlock(&mntvnode_mtx);
}
/*
* Create the VM object needed for VMIO and mmap support. This
* is done for all VREG files in the system. Some filesystems might
* afford the additional metadata buffering capability of the
* VMIO code by making the device node be VMIO mode also.
*
* vp must be locked when vfs_object_create is called.
*/
int
vfs_object_create(vp, td, cred)
struct vnode *vp;
struct thread *td;
struct ucred *cred;
{
GIANT_REQUIRED;
return (VOP_CREATEVOBJECT(vp, cred, td));
}
/*
* Mark a vnode as free, putting it up for recycling.
*/
void
vfree(vp)
struct vnode *vp;
{
int s;
s = splbio();
mtx_lock(&vnode_free_list_mtx);
KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free"));
if (vp->v_flag & VAGE) {
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
} else {
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
}
freevnodes++;
mtx_unlock(&vnode_free_list_mtx);
vp->v_flag &= ~VAGE;
vp->v_flag |= VFREE;
splx(s);
}
/*
* Opposite of vfree() - mark a vnode as in use.
*/
void
vbusy(vp)
struct vnode *vp;
{
int s;
s = splbio();
mtx_lock(&vnode_free_list_mtx);
KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free"));
TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
freevnodes--;
mtx_unlock(&vnode_free_list_mtx);
vp->v_flag &= ~(VFREE|VAGE);
splx(s);
}
/*
* Record a process's interest in events which might happen to
* a vnode. Because poll uses the historic select-style interface
* internally, this routine serves as both the ``check for any
* pending events'' and the ``record my interest in future events''
* functions. (These are done together, while the lock is held,
* to avoid race conditions.)
*/
int
vn_pollrecord(vp, td, events)
struct vnode *vp;
struct thread *td;
short events;
{
mtx_lock(&vp->v_pollinfo.vpi_lock);
if (vp->v_pollinfo.vpi_revents & events) {
/*
* This leaves events we are not interested
* in available for the other process which
* which presumably had requested them
* (otherwise they would never have been
* recorded).
*/
events &= vp->v_pollinfo.vpi_revents;
vp->v_pollinfo.vpi_revents &= ~events;
mtx_unlock(&vp->v_pollinfo.vpi_lock);
return events;
}
vp->v_pollinfo.vpi_events |= events;
selrecord(td, &vp->v_pollinfo.vpi_selinfo);
mtx_unlock(&vp->v_pollinfo.vpi_lock);
return 0;
}
/*
* Note the occurrence of an event. If the VN_POLLEVENT macro is used,
* it is possible for us to miss an event due to race conditions, but
* that condition is expected to be rare, so for the moment it is the
* preferred interface.
*/
void
vn_pollevent(vp, events)
struct vnode *vp;
short events;
{
mtx_lock(&vp->v_pollinfo.vpi_lock);
if (vp->v_pollinfo.vpi_events & events) {
/*
* We clear vpi_events so that we don't
* call selwakeup() twice if two events are
* posted before the polling process(es) is
* awakened. This also ensures that we take at
* most one selwakeup() if the polling process
* is no longer interested. However, it does
* mean that only one event can be noticed at
* a time. (Perhaps we should only clear those
* event bits which we note?) XXX
*/
vp->v_pollinfo.vpi_events = 0; /* &= ~events ??? */
vp->v_pollinfo.vpi_revents |= events;
selwakeup(&vp->v_pollinfo.vpi_selinfo);
}
mtx_unlock(&vp->v_pollinfo.vpi_lock);
}
#define VN_KNOTE(vp, b) \
KNOTE((struct klist *)&vp->v_pollinfo.vpi_selinfo.si_note, (b))
/*
* Wake up anyone polling on vp because it is being revoked.
* This depends on dead_poll() returning POLLHUP for correct
* behavior.
*/
void
vn_pollgone(vp)
struct vnode *vp;
{
mtx_lock(&vp->v_pollinfo.vpi_lock);
VN_KNOTE(vp, NOTE_REVOKE);
if (vp->v_pollinfo.vpi_events) {
vp->v_pollinfo.vpi_events = 0;
selwakeup(&vp->v_pollinfo.vpi_selinfo);
}
mtx_unlock(&vp->v_pollinfo.vpi_lock);
}
/*
* Routine to create and manage a filesystem syncer vnode.
*/
#define sync_close ((int (*) __P((struct vop_close_args *)))nullop)
static int sync_fsync __P((struct vop_fsync_args *));
static int sync_inactive __P((struct vop_inactive_args *));
static int sync_reclaim __P((struct vop_reclaim_args *));
#define sync_lock ((int (*) __P((struct vop_lock_args *)))vop_nolock)
#define sync_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock)
static int sync_print __P((struct vop_print_args *));
#define sync_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked)
static vop_t **sync_vnodeop_p;
static struct vnodeopv_entry_desc sync_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_eopnotsupp },
{ &vop_close_desc, (vop_t *) sync_close }, /* close */
{ &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */
{ &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */
{ &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */
{ &vop_lock_desc, (vop_t *) sync_lock }, /* lock */
{ &vop_unlock_desc, (vop_t *) sync_unlock }, /* unlock */
{ &vop_print_desc, (vop_t *) sync_print }, /* print */
{ &vop_islocked_desc, (vop_t *) sync_islocked }, /* islocked */
{ NULL, NULL }
};
static struct vnodeopv_desc sync_vnodeop_opv_desc =
{ &sync_vnodeop_p, sync_vnodeop_entries };
VNODEOP_SET(sync_vnodeop_opv_desc);
/*
* Create a new filesystem syncer vnode for the specified mount point.
*/
int
vfs_allocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
static long start, incr, next;
int error;
/* Allocate a new vnode */
if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) {
mp->mnt_syncer = NULL;
return (error);
}
vp->v_type = VNON;
/*
* Place the vnode onto the syncer worklist. We attempt to
* scatter them about on the list so that they will go off
* at evenly distributed times even if all the filesystems
* are mounted at once.
*/
next += incr;
if (next == 0 || next > syncer_maxdelay) {
start /= 2;
incr /= 2;
if (start == 0) {
start = syncer_maxdelay / 2;
incr = syncer_maxdelay;
}
next = start;
}
vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0);
mp->mnt_syncer = vp;
return (0);
}
/*
* Do a lazy sync of the filesystem.
*/
static int
sync_fsync(ap)
struct vop_fsync_args /* {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct thread *a_td;
} */ *ap;
{
struct vnode *syncvp = ap->a_vp;
struct mount *mp = syncvp->v_mount;
struct thread *td = ap->a_td;
int asyncflag;
/*
* We only need to do something if this is a lazy evaluation.
*/
if (ap->a_waitfor != MNT_LAZY)
return (0);
/*
* Move ourselves to the back of the sync list.
*/
vn_syncer_add_to_worklist(syncvp, syncdelay);
/*
* Walk the list of vnodes pushing all that are dirty and
* not already on the sync list.
*/
mtx_lock(&mountlist_mtx);
if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) {
mtx_unlock(&mountlist_mtx);
return (0);
}
if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
vfs_unbusy(mp, td);
return (0);
}
asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
vfs_msync(mp, MNT_NOWAIT);
VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td);
if (asyncflag)
mp->mnt_flag |= MNT_ASYNC;
vn_finished_write(mp);
vfs_unbusy(mp, td);
return (0);
}
/*
* The syncer vnode is no referenced.
*/
static int
sync_inactive(ap)
struct vop_inactive_args /* {
struct vnode *a_vp;
struct thread *a_td;
} */ *ap;
{
vgone(ap->a_vp);
return (0);
}
/*
* The syncer vnode is no longer needed and is being decommissioned.
*
* Modifications to the worklist must be protected at splbio().
*/
static int
sync_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
int s;
s = splbio();
vp->v_mount->mnt_syncer = NULL;
if (vp->v_flag & VONWORKLST) {
LIST_REMOVE(vp, v_synclist);
vp->v_flag &= ~VONWORKLST;
}
splx(s);
return (0);
}
/*
* Print out a syncer vnode.
*/
static int
sync_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
printf("syncer vnode");
if (vp->v_vnlock != NULL)
lockmgr_printinfo(vp->v_vnlock);
printf("\n");
return (0);
}
/*
* extract the dev_t from a VCHR
*/
dev_t
vn_todev(vp)
struct vnode *vp;
{
if (vp->v_type != VCHR)
return (NODEV);
return (vp->v_rdev);
}
/*
* Check if vnode represents a disk device
*/
int
vn_isdisk(vp, errp)
struct vnode *vp;
int *errp;
{
struct cdevsw *cdevsw;
if (vp->v_type != VCHR) {
if (errp != NULL)
*errp = ENOTBLK;
return (0);
}
if (vp->v_rdev == NULL) {
if (errp != NULL)
*errp = ENXIO;
return (0);
}
cdevsw = devsw(vp->v_rdev);
if (cdevsw == NULL) {
if (errp != NULL)
*errp = ENXIO;
return (0);
}
if (!(cdevsw->d_flags & D_DISK)) {
if (errp != NULL)
*errp = ENOTBLK;
return (0);
}
if (errp != NULL)
*errp = 0;
return (1);
}
/*
* Free data allocated by namei(); see namei(9) for details.
*/
void
NDFREE(ndp, flags)
struct nameidata *ndp;
const uint flags;
{
if (!(flags & NDF_NO_FREE_PNBUF) &&
(ndp->ni_cnd.cn_flags & HASBUF)) {
zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
ndp->ni_cnd.cn_flags &= ~HASBUF;
}
if (!(flags & NDF_NO_DVP_UNLOCK) &&
(ndp->ni_cnd.cn_flags & LOCKPARENT) &&
ndp->ni_dvp != ndp->ni_vp)
VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread);
if (!(flags & NDF_NO_DVP_RELE) &&
(ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) {
vrele(ndp->ni_dvp);
ndp->ni_dvp = NULL;
}
if (!(flags & NDF_NO_VP_UNLOCK) &&
(ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp)
VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread);
if (!(flags & NDF_NO_VP_RELE) &&
ndp->ni_vp) {
vrele(ndp->ni_vp);
ndp->ni_vp = NULL;
}
if (!(flags & NDF_NO_STARTDIR_RELE) &&
(ndp->ni_cnd.cn_flags & SAVESTART)) {
vrele(ndp->ni_startdir);
ndp->ni_startdir = NULL;
}
}
/*
* Common file system 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. Returns 0 on success, or an errno on failure.
*/
int
vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused)
enum vtype type;
mode_t file_mode;
uid_t file_uid;
gid_t file_gid;
mode_t acc_mode;
struct ucred *cred;
int *privused;
{
mode_t dac_granted;
#ifdef CAPABILITIES
mode_t cap_granted;
#endif
/*
* Look for a normal, non-privileged way to access the file/directory
* as requested. If it exists, go with that.
*/
if (privused != NULL)
*privused = 0;
dac_granted = 0;
/* Check the owner. */
if (cred->cr_uid == file_uid) {
dac_granted |= VADMIN;
if (file_mode & S_IXUSR)
dac_granted |= VEXEC;
if (file_mode & S_IRUSR)
dac_granted |= VREAD;
if (file_mode & S_IWUSR)
dac_granted |= VWRITE;
if ((acc_mode & dac_granted) == acc_mode)
return (0);
goto privcheck;
}
/* Otherwise, check the groups (first match) */
if (groupmember(file_gid, cred)) {
if (file_mode & S_IXGRP)
dac_granted |= VEXEC;
if (file_mode & S_IRGRP)
dac_granted |= VREAD;
if (file_mode & S_IWGRP)
dac_granted |= VWRITE;
if ((acc_mode & dac_granted) == acc_mode)
return (0);
goto privcheck;
}
/* Otherwise, check everyone else. */
if (file_mode & S_IXOTH)
dac_granted |= VEXEC;
if (file_mode & S_IROTH)
dac_granted |= VREAD;
if (file_mode & S_IWOTH)
dac_granted |= VWRITE;
if ((acc_mode & dac_granted) == acc_mode)
return (0);
privcheck:
if (!suser_xxx(cred, NULL, PRISON_ROOT)) {
/* XXX audit: privilege used */
if (privused != NULL)
*privused = 1;
return (0);
}
#ifdef CAPABILITIES
/*
* Build a capability mask to determine if the set of capabilities
* satisfies the requirements when combined with the granted mask
* from above.
* For each capability, if the capability is required, bitwise
* or the request type onto the cap_granted mask.
*/
cap_granted = 0;
if (type == VDIR) {
/*
* For directories, use CAP_DAC_READ_SEARCH to satisfy
* VEXEC requests, instead of CAP_DAC_EXECUTE.
*/
if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
!cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT))
cap_granted |= VEXEC;
} else {
if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
!cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT))
cap_granted |= VEXEC;
}
if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) &&
!cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT))
cap_granted |= VREAD;
if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
!cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT))
cap_granted |= VWRITE;
if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
!cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT))
cap_granted |= VADMIN;
if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) {
/* XXX audit: privilege used */
if (privused != NULL)
*privused = 1;
return (0);
}
#endif
return ((acc_mode & VADMIN) ? EPERM : EACCES);
}
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