diff options
Diffstat (limited to 'sys/kern/vfs_subr.c')
| -rw-r--r-- | sys/kern/vfs_subr.c | 3833 |
1 files changed, 3833 insertions, 0 deletions
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c new file mode 100644 index 0000000..cf0f0fb --- /dev/null +++ b/sys/kern/vfs_subr.c @@ -0,0 +1,3833 @@ +/* + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * (c) UNIX System Laboratories, Inc. + * All or some portions of this file are derived from material licensed + * to the University of California by American Telephone and Telegraph + * Co. or Unix System Laboratories, Inc. and are reproduced herein with + * the permission of UNIX System Laboratories, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 + */ + +/* + * External virtual filesystem routines + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_ddb.h" +#include "opt_mac.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/extattr.h> +#include <sys/fcntl.h> +#include <sys/kernel.h> +#include <sys/kthread.h> +#include <sys/mac.h> +#include <sys/malloc.h> +#include <sys/mount.h> +#include <sys/namei.h> +#include <sys/stat.h> +#include <sys/sysctl.h> +#include <sys/syslog.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_kern.h> +#include <vm/uma.h> + +static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure"); + +static void addalias(struct vnode *vp, dev_t nvp_rdev); +static void insmntque(struct vnode *vp, struct mount *mp); +static void vclean(struct vnode *vp, int flags, struct thread *td); +static void vlruvp(struct vnode *vp); +static int flushbuflist(struct buf *blist, int flags, struct vnode *vp, + int slpflag, int slptimeo, int *errorp); +static int vcanrecycle(struct vnode *vp, struct mount **vnmpp); + + +/* + * Number of vnodes in existence. Increased whenever getnewvnode() + * allocates a new vnode, never decreased. + */ +static unsigned long numvnodes; + +SYSCTL_LONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, ""); + +/* + * Conversion tables for conversion from vnode types to inode formats + * and back. + */ +enum vtype iftovt_tab[16] = { + VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, + VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, +}; +int vttoif_tab[9] = { + 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, + S_IFSOCK, S_IFIFO, S_IFMT, +}; + +/* + * List of vnodes that are ready for recycling. + */ +static TAILQ_HEAD(freelst, vnode) vnode_free_list; + +/* + * Minimum number of free vnodes. If there are fewer than this free vnodes, + * getnewvnode() will return a newly allocated vnode. + */ +static u_long wantfreevnodes = 25; +SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, ""); +/* Number of vnodes in the free list. */ +static u_long freevnodes; +SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, ""); + +/* + * Various variables used for debugging the new implementation of + * reassignbuf(). + * XXX these are probably of (very) limited utility now. + */ +static int reassignbufcalls; +SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, ""); +static int nameileafonly; +SYSCTL_INT(_vfs, OID_AUTO, nameileafonly, CTLFLAG_RW, &nameileafonly, 0, ""); + +/* + * Cache for the mount type id assigned to NFS. This is used for + * special checks in nfs/nfs_nqlease.c and vm/vnode_pager.c. + */ +int nfs_mount_type = -1; + +/* To keep more than one thread at a time from running vfs_getnewfsid */ +static struct mtx mntid_mtx; + +/* + * Lock for any access to the following: + * vnode_free_list + * numvnodes + * freevnodes + */ +static struct mtx vnode_free_list_mtx; + +/* + * For any iteration/modification of dev->si_hlist (linked through + * v_specnext) + */ +static struct mtx spechash_mtx; + +/* Publicly exported FS */ +struct nfs_public nfs_pub; + +/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */ +static uma_zone_t vnode_zone; +static uma_zone_t vnodepoll_zone; + +/* Set to 1 to print out reclaim of active vnodes */ +int prtactive; + +/* + * The workitem queue. + * + * It is useful to delay writes of file data and filesystem metadata + * for tens of seconds so that quickly created and deleted files need + * not waste disk bandwidth being created and removed. To realize this, + * we append vnodes to a "workitem" queue. When running with a soft + * updates implementation, most pending metadata dependencies should + * not wait for more than a few seconds. Thus, mounted on block devices + * are delayed only about a half the time that file data is delayed. + * Similarly, directory updates are more critical, so are only delayed + * about a third the time that file data is delayed. Thus, there are + * SYNCER_MAXDELAY queues that are processed round-robin at a rate of + * one each second (driven off the filesystem syncer process). The + * syncer_delayno variable indicates the next queue that is to be processed. + * Items that need to be processed soon are placed in this queue: + * + * syncer_workitem_pending[syncer_delayno] + * + * A delay of fifteen seconds is done by placing the request fifteen + * entries later in the queue: + * + * syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask] + * + */ +static int syncer_delayno; +static long syncer_mask; +LIST_HEAD(synclist, vnode); +static struct synclist *syncer_workitem_pending; +/* + * The sync_mtx protects: + * vp->v_synclist + * syncer_delayno + * syncer_workitem_pending + * rushjob + */ +static struct mtx sync_mtx; + +#define SYNCER_MAXDELAY 32 +static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */ +static int syncdelay = 30; /* max time to delay syncing data */ +static int filedelay = 30; /* time to delay syncing files */ +SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0, ""); +static int dirdelay = 29; /* time to delay syncing directories */ +SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0, ""); +static int metadelay = 28; /* time to delay syncing metadata */ +SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0, ""); +static int rushjob; /* number of slots to run ASAP */ +static int stat_rush_requests; /* number of times I/O speeded up */ +SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, ""); + +/* + * Number of vnodes we want to exist at any one time. This is mostly used + * to size hash tables in vnode-related code. It is normally not used in + * getnewvnode(), as wantfreevnodes is normally nonzero.) + * + * XXX desiredvnodes is historical cruft and should not exist. + */ +int desiredvnodes; +SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW, + &desiredvnodes, 0, "Maximum number of vnodes"); +static int minvnodes; +SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, + &minvnodes, 0, "Minimum number of vnodes"); +static int vnlru_nowhere; +SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, + "Number of times the vnlru process ran without success"); + +/* Hook for calling soft updates */ +int (*softdep_process_worklist_hook)(struct mount *); + +/* + * This only exists to supress warnings from unlocked specfs accesses. It is + * no longer ok to have an unlocked VFS. + */ +#define IGNORE_LOCK(vp) ((vp)->v_type == VCHR || (vp)->v_type == VBAD) + +/* Print lock violations */ +int vfs_badlock_print = 1; + +/* Panic on violation */ +int vfs_badlock_panic = 1; + +/* Check for interlock across VOPs */ +int vfs_badlock_mutex = 1; + +static void +vfs_badlock(char *msg, char *str, struct vnode *vp) +{ + if (vfs_badlock_print) + printf("%s: %p %s\n", str, vp, msg); + if (vfs_badlock_panic) + Debugger("Lock violation.\n"); +} + +void +assert_vi_unlocked(struct vnode *vp, char *str) +{ + if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp))) + vfs_badlock("interlock is locked but should not be", str, vp); +} + +void +assert_vi_locked(struct vnode *vp, char *str) +{ + if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp))) + vfs_badlock("interlock is not locked but should be", str, vp); +} + +void +assert_vop_locked(struct vnode *vp, char *str) +{ + if (vp && !IGNORE_LOCK(vp) && !VOP_ISLOCKED(vp, NULL)) + vfs_badlock("is not locked but should be", str, vp); +} + +void +assert_vop_unlocked(struct vnode *vp, char *str) +{ + if (vp && !IGNORE_LOCK(vp) && + VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) + vfs_badlock("is locked but should not be", str, vp); +} + +void +assert_vop_elocked(struct vnode *vp, char *str) +{ + if (vp && !IGNORE_LOCK(vp) && + VOP_ISLOCKED(vp, curthread) != LK_EXCLUSIVE) + vfs_badlock("is not exclusive locked but should be", str, vp); +} + +void +assert_vop_elocked_other(struct vnode *vp, char *str) +{ + if (vp && !IGNORE_LOCK(vp) && + VOP_ISLOCKED(vp, curthread) != LK_EXCLOTHER) + vfs_badlock("is not exclusive locked by another thread", + str, vp); +} + +void +assert_vop_slocked(struct vnode *vp, char *str) +{ + if (vp && !IGNORE_LOCK(vp) && + VOP_ISLOCKED(vp, curthread) != LK_SHARED) + vfs_badlock("is not locked shared but should be", str, vp); +} + +void +vop_rename_pre(void *ap) +{ + struct vop_rename_args *a = ap; + + if (a->a_tvp) + ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME"); + ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME"); + ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME"); + ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME"); + + /* Check the source (from) */ + if (a->a_tdvp != a->a_fdvp) + ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked.\n"); + if (a->a_tvp != a->a_fvp) + ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: tvp locked.\n"); + + /* Check the target */ + if (a->a_tvp) + ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked.\n"); + + ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked.\n"); +} + +void +vop_strategy_pre(void *ap) +{ + struct vop_strategy_args *a = ap; + struct buf *bp; + + bp = a->a_bp; + + /* + * Cluster ops lock their component buffers but not the IO container. + */ + if ((bp->b_flags & B_CLUSTER) != 0) + return; + + if (BUF_REFCNT(bp) < 1) { + if (vfs_badlock_print) + printf("VOP_STRATEGY: bp is not locked but should be.\n"); + if (vfs_badlock_panic) + Debugger("Lock violation.\n"); + } +} + +void +vop_lookup_pre(void *ap) +{ + struct vop_lookup_args *a = ap; + struct vnode *dvp; + + dvp = a->a_dvp; + + ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); + ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP"); +} + +void +vop_lookup_post(void *ap, int rc) +{ + struct vop_lookup_args *a = ap; + struct componentname *cnp; + struct vnode *dvp; + struct vnode *vp; + int flags; + + dvp = a->a_dvp; + cnp = a->a_cnp; + vp = *(a->a_vpp); + flags = cnp->cn_flags; + + + ASSERT_VI_UNLOCKED(dvp, "VOP_LOOKUP"); + /* + * If this is the last path component for this lookup and LOCPARENT + * is set, OR if there is an error the directory has to be locked. + */ + if ((flags & LOCKPARENT) && (flags & ISLASTCN)) + ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (LOCKPARENT)"); + else if (rc != 0) + ASSERT_VOP_LOCKED(dvp, "VOP_LOOKUP (error)"); + else if (dvp != vp) + ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (dvp)"); + + if (flags & PDIRUNLOCK) + ASSERT_VOP_UNLOCKED(dvp, "VOP_LOOKUP (PDIRUNLOCK)"); +} + +void +vop_unlock_pre(void *ap) +{ + struct vop_unlock_args *a = ap; + + if (a->a_flags & LK_INTERLOCK) + ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK"); + + ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK"); +} + +void +vop_unlock_post(void *ap, int rc) +{ + struct vop_unlock_args *a = ap; + + if (a->a_flags & LK_INTERLOCK) + ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK"); +} + +void +vop_lock_pre(void *ap) +{ + struct vop_lock_args *a = ap; + + if ((a->a_flags & LK_INTERLOCK) == 0) + ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); + else + ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK"); +} + +void +vop_lock_post(void *ap, int rc) +{ + struct vop_lock_args *a; + + a = ap; + + ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK"); + if (rc == 0) + ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK"); +} + +void +v_addpollinfo(struct vnode *vp) +{ + vp->v_pollinfo = uma_zalloc(vnodepoll_zone, M_WAITOK); + mtx_init(&vp->v_pollinfo->vpi_lock, "vnode pollinfo", NULL, MTX_DEF); +} + +/* + * Initialize the vnode management data structures. + */ +static void +vntblinit(void *dummy __unused) +{ + + /* + * Desiredvnodes is a function of the physical memory size and + * the kernel's heap size. Specifically, desiredvnodes scales + * in proportion to the physical memory size until two fifths + * of the kernel's heap size is consumed by vnodes and vm + * objects. + */ + desiredvnodes = min(maxproc + cnt.v_page_count / 4, 2 * vm_kmem_size / + (5 * (sizeof(struct vm_object) + sizeof(struct vnode)))); + minvnodes = desiredvnodes / 4; + mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF); + mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF); + mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF); + mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF); + TAILQ_INIT(&vnode_free_list); + mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF); + vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL, + NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo), + NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + /* + * Initialize the filesystem syncer. + */ + syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE, + &syncer_mask); + syncer_maxdelay = syncer_mask + 1; + mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF); +} +SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL) + + +/* + * Mark a mount point as busy. Used to synchronize access and to delay + * unmounting. Interlock is not released on failure. + */ +int +vfs_busy(mp, flags, interlkp, td) + struct mount *mp; + int flags; + struct mtx *interlkp; + struct thread *td; +{ + int lkflags; + + if (mp->mnt_kern_flag & MNTK_UNMOUNT) { + if (flags & LK_NOWAIT) + return (ENOENT); + mp->mnt_kern_flag |= MNTK_MWAIT; + /* + * Since all busy locks are shared except the exclusive + * lock granted when unmounting, the only place that a + * wakeup needs to be done is at the release of the + * exclusive lock at the end of dounmount. + */ + msleep(mp, interlkp, PVFS, "vfs_busy", 0); + return (ENOENT); + } + lkflags = LK_SHARED | LK_NOPAUSE; + if (interlkp) + lkflags |= LK_INTERLOCK; + if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td)) + panic("vfs_busy: unexpected lock failure"); + return (0); +} + +/* + * Free a busy filesystem. + */ +void +vfs_unbusy(mp, td) + struct mount *mp; + struct thread *td; +{ + + lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); +} + +/* + * Lookup a mount point by filesystem identifier. + */ +struct mount * +vfs_getvfs(fsid) + fsid_t *fsid; +{ + register struct mount *mp; + + mtx_lock(&mountlist_mtx); + TAILQ_FOREACH(mp, &mountlist, mnt_list) { + if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && + mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) { + mtx_unlock(&mountlist_mtx); + return (mp); + } + } + mtx_unlock(&mountlist_mtx); + return ((struct mount *) 0); +} + +/* + * Get a new unique fsid. Try to make its val[0] unique, since this value + * will be used to create fake device numbers for stat(). Also try (but + * not so hard) make its val[0] unique mod 2^16, since some emulators only + * support 16-bit device numbers. We end up with unique val[0]'s for the + * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls. + * + * Keep in mind that several mounts may be running in parallel. Starting + * the search one past where the previous search terminated is both a + * micro-optimization and a defense against returning the same fsid to + * different mounts. + */ +void +vfs_getnewfsid(mp) + struct mount *mp; +{ + static u_int16_t mntid_base; + fsid_t tfsid; + int mtype; + + mtx_lock(&mntid_mtx); + mtype = mp->mnt_vfc->vfc_typenum; + tfsid.val[1] = mtype; + mtype = (mtype & 0xFF) << 24; + for (;;) { + tfsid.val[0] = makeudev(255, + mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF)); + mntid_base++; + if (vfs_getvfs(&tfsid) == NULL) + break; + } + mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; + mp->mnt_stat.f_fsid.val[1] = tfsid.val[1]; + mtx_unlock(&mntid_mtx); +} + +/* + * Knob to control the precision of file timestamps: + * + * 0 = seconds only; nanoseconds zeroed. + * 1 = seconds and nanoseconds, accurate within 1/HZ. + * 2 = seconds and nanoseconds, truncated to microseconds. + * >=3 = seconds and nanoseconds, maximum precision. + */ +enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC }; + +static int timestamp_precision = TSP_SEC; +SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW, + ×tamp_precision, 0, ""); + +/* + * Get a current timestamp. + */ +void +vfs_timestamp(tsp) + struct timespec *tsp; +{ + struct timeval tv; + + switch (timestamp_precision) { + case TSP_SEC: + tsp->tv_sec = time_second; + tsp->tv_nsec = 0; + break; + case TSP_HZ: + getnanotime(tsp); + break; + case TSP_USEC: + microtime(&tv); + TIMEVAL_TO_TIMESPEC(&tv, tsp); + break; + case TSP_NSEC: + default: + nanotime(tsp); + break; + } +} + +/* + * Set vnode attributes to VNOVAL + */ +void +vattr_null(vap) + register struct vattr *vap; +{ + + vap->va_type = VNON; + vap->va_size = VNOVAL; + vap->va_bytes = VNOVAL; + vap->va_mode = VNOVAL; + vap->va_nlink = VNOVAL; + vap->va_uid = VNOVAL; + vap->va_gid = VNOVAL; + vap->va_fsid = VNOVAL; + vap->va_fileid = VNOVAL; + vap->va_blocksize = VNOVAL; + vap->va_rdev = VNOVAL; + vap->va_atime.tv_sec = VNOVAL; + vap->va_atime.tv_nsec = VNOVAL; + vap->va_mtime.tv_sec = VNOVAL; + vap->va_mtime.tv_nsec = VNOVAL; + vap->va_ctime.tv_sec = VNOVAL; + vap->va_ctime.tv_nsec = VNOVAL; + vap->va_birthtime.tv_sec = VNOVAL; + vap->va_birthtime.tv_nsec = VNOVAL; + vap->va_flags = VNOVAL; + vap->va_gen = VNOVAL; + vap->va_vaflags = 0; +} + +/* + * This routine is called when we have too many vnodes. It attempts + * to free <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 kern.maxvnodes too low. + */ +static int +vlrureclaim(struct mount *mp) +{ + struct vnode *vp; + int done; + int trigger; + int usevnodes; + int count; + + /* + * Calculate the trigger point, don't allow user + * screwups to blow us up. This prevents us from + * recycling vnodes with lots of resident pages. We + * aren't trying to free memory, we are trying to + * free vnodes. + */ + usevnodes = desiredvnodes; + if (usevnodes <= 0) + usevnodes = 1; + trigger = cnt.v_page_count * 2 / usevnodes; + + done = 0; + mtx_lock(&mntvnode_mtx); + count = mp->mnt_nvnodelistsize / 10 + 1; + while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) { + TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + + if (vp->v_type != VNON && + vp->v_type != VBAD && + VI_TRYLOCK(vp)) { + if (VMIGHTFREE(vp) && /* critical path opt */ + (vp->v_object == NULL || + vp->v_object->resident_page_count < trigger)) { + mtx_unlock(&mntvnode_mtx); + vgonel(vp, curthread); + done++; + mtx_lock(&mntvnode_mtx); + } else + VI_UNLOCK(vp); + } + --count; + } + mtx_unlock(&mntvnode_mtx); + return done; +} + +/* + * Attempt to recycle vnodes in a context that is always safe to block. + * Calling vlrurecycle() from the bowels of filesystem code has some + * interesting deadlock problems. + */ +static struct proc *vnlruproc; +static int vnlruproc_sig; + +static void +vnlru_proc(void) +{ + struct mount *mp, *nmp; + int s; + int done; + struct proc *p = vnlruproc; + struct thread *td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ + + mtx_lock(&Giant); + + EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, p, + SHUTDOWN_PRI_FIRST); + + s = splbio(); + for (;;) { + kthread_suspend_check(p); + mtx_lock(&vnode_free_list_mtx); + if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) { + mtx_unlock(&vnode_free_list_mtx); + vnlruproc_sig = 0; + wakeup(&vnlruproc_sig); + tsleep(vnlruproc, PVFS, "vlruwt", hz); + continue; + } + mtx_unlock(&vnode_free_list_mtx); + done = 0; + mtx_lock(&mountlist_mtx); + for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { + if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) { + nmp = TAILQ_NEXT(mp, mnt_list); + continue; + } + done += vlrureclaim(mp); + mtx_lock(&mountlist_mtx); + nmp = TAILQ_NEXT(mp, mnt_list); + vfs_unbusy(mp, td); + } + mtx_unlock(&mountlist_mtx); + if (done == 0) { +#if 0 + /* These messages are temporary debugging aids */ + if (vnlru_nowhere < 5) + printf("vnlru process getting nowhere..\n"); + else if (vnlru_nowhere == 5) + printf("vnlru process messages stopped.\n"); +#endif + vnlru_nowhere++; + tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); + } + } + splx(s); +} + +static struct kproc_desc vnlru_kp = { + "vnlru", + vnlru_proc, + &vnlruproc +}; +SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp) + + +/* + * Routines having to do with the management of the vnode table. + */ + +/* + * Check to see if a free vnode can be recycled. If it can, + * return it locked with the vn lock, but not interlock. Also + * get the vn_start_write lock. Otherwise indicate the error. + */ +static int +vcanrecycle(struct vnode *vp, struct mount **vnmpp) +{ + struct thread *td = curthread; + vm_object_t object; + int error; + + /* Don't recycle if we can't get the interlock */ + if (!VI_TRYLOCK(vp)) + return (EWOULDBLOCK); + + /* We should be able to immediately acquire this */ + /* XXX This looks like it should panic if it fails */ + if (vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td) != 0) { + if (VOP_ISLOCKED(vp, td)) + panic("vcanrecycle: locked vnode"); + return (EWOULDBLOCK); + } + + /* + * Don't recycle if its filesystem is being suspended. + */ + if (vn_start_write(vp, vnmpp, V_NOWAIT) != 0) { + error = EBUSY; + goto done; + } + + /* + * Don't recycle if we still have cached pages. + */ + if (VOP_GETVOBJECT(vp, &object) == 0) { + VM_OBJECT_LOCK(object); + if (object->resident_page_count || + object->ref_count) { + VM_OBJECT_UNLOCK(object); + error = EBUSY; + goto done; + } + VM_OBJECT_UNLOCK(object); + } + if (LIST_FIRST(&vp->v_cache_src)) { + /* + * note: nameileafonly sysctl is temporary, + * for debugging only, and will eventually be + * removed. + */ + if (nameileafonly > 0) { + /* + * Do not reuse namei-cached directory + * vnodes that have cached + * subdirectories. + */ + if (cache_leaf_test(vp) < 0) { + error = EISDIR; + goto done; + } + } else if (nameileafonly < 0 || + vmiodirenable == 0) { + /* + * Do not reuse namei-cached directory + * vnodes if nameileafonly is -1 or + * if VMIO backing for directories is + * turned off (otherwise we reuse them + * too quickly). + */ + error = EBUSY; + goto done; + } + } + return (0); +done: + VOP_UNLOCK(vp, 0, td); + return (error); +} + +/* + * Return the next vnode from the free list. + */ +int +getnewvnode(tag, mp, vops, vpp) + const char *tag; + struct mount *mp; + vop_t **vops; + struct vnode **vpp; +{ + struct thread *td = curthread; /* XXX */ + struct vnode *vp = NULL; + struct vpollinfo *pollinfo = NULL; + struct mount *vnmp; + + mtx_lock(&vnode_free_list_mtx); + + /* + * Try to reuse vnodes if we hit the max. This situation only + * occurs in certain large-memory (2G+) situations. We cannot + * attempt to directly reclaim vnodes due to nasty recursion + * problems. + */ + while (numvnodes - freevnodes > desiredvnodes) { + if (vnlruproc_sig == 0) { + vnlruproc_sig = 1; /* avoid unnecessary wakeups */ + wakeup(vnlruproc); + } + mtx_unlock(&vnode_free_list_mtx); + tsleep(&vnlruproc_sig, PVFS, "vlruwk", hz); + mtx_lock(&vnode_free_list_mtx); + } + + /* + * Attempt to reuse a vnode already on the free list, allocating + * a new vnode if we can't find one or if we have not reached a + * good minimum for good LRU performance. + */ + + if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) { + int error; + int count; + + for (count = 0; count < freevnodes; count++) { + vp = TAILQ_FIRST(&vnode_free_list); + + KASSERT(vp->v_usecount == 0 && + (vp->v_iflag & VI_DOINGINACT) == 0, + ("getnewvnode: free vnode isn't")); + + TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); + /* + * We have to drop the free list mtx to avoid lock + * order reversals with interlock. + */ + mtx_unlock(&vnode_free_list_mtx); + error = vcanrecycle(vp, &vnmp); + mtx_lock(&vnode_free_list_mtx); + if (error == 0) + break; + TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); + vp = NULL; + } + } + if (vp) { + freevnodes--; + mtx_unlock(&vnode_free_list_mtx); + + cache_purge(vp); + VI_LOCK(vp); + vp->v_iflag |= VI_DOOMED; + vp->v_iflag &= ~VI_FREE; + if (vp->v_type != VBAD) { + VOP_UNLOCK(vp, 0, td); + vgonel(vp, td); + VI_LOCK(vp); + } else { + VOP_UNLOCK(vp, 0, td); + } + vn_finished_write(vnmp); + +#ifdef INVARIANTS + { + if (vp->v_data) + panic("cleaned vnode isn't"); + if (vp->v_numoutput) + panic("Clean vnode has pending I/O's"); + if (vp->v_writecount != 0) + panic("Non-zero write count"); + } +#endif + if ((pollinfo = vp->v_pollinfo) != NULL) { + /* + * To avoid lock order reversals, the call to + * uma_zfree() must be delayed until the vnode + * interlock is released. + */ + vp->v_pollinfo = NULL; + } +#ifdef MAC + mac_destroy_vnode(vp); +#endif + vp->v_iflag = 0; + vp->v_vflag = 0; + vp->v_lastw = 0; + vp->v_lasta = 0; + vp->v_cstart = 0; + vp->v_clen = 0; + vp->v_socket = 0; + lockdestroy(vp->v_vnlock); + lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); + KASSERT(vp->v_cleanbufcnt == 0, ("cleanbufcnt not 0")); + KASSERT(vp->v_cleanblkroot == NULL, ("cleanblkroot not NULL")); + KASSERT(vp->v_dirtybufcnt == 0, ("dirtybufcnt not 0")); + KASSERT(vp->v_dirtyblkroot == NULL, ("dirtyblkroot not NULL")); + } else { + numvnodes++; + mtx_unlock(&vnode_free_list_mtx); + + vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK|M_ZERO); + mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF); + VI_LOCK(vp); + vp->v_dd = vp; + vp->v_vnlock = &vp->v_lock; + lockinit(vp->v_vnlock, PVFS, tag, VLKTIMEOUT, LK_NOPAUSE); + cache_purge(vp); + LIST_INIT(&vp->v_cache_src); + TAILQ_INIT(&vp->v_cache_dst); + } + + TAILQ_INIT(&vp->v_cleanblkhd); + TAILQ_INIT(&vp->v_dirtyblkhd); + vp->v_type = VNON; + vp->v_tag = tag; + vp->v_op = vops; + *vpp = vp; + vp->v_usecount = 1; + vp->v_data = 0; + vp->v_cachedid = -1; + VI_UNLOCK(vp); + if (pollinfo != NULL) { + mtx_destroy(&pollinfo->vpi_lock); + uma_zfree(vnodepoll_zone, pollinfo); + } +#ifdef MAC + mac_init_vnode(vp); + if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0) + mac_associate_vnode_singlelabel(mp, vp); +#endif + insmntque(vp, mp); + + return (0); +} + +/* + * Move a vnode from one mount queue to another. + */ +static void +insmntque(vp, mp) + register struct vnode *vp; + register struct mount *mp; +{ + + mtx_lock(&mntvnode_mtx); + /* + * Delete from old mount point vnode list, if on one. + */ + if (vp->v_mount != NULL) { + KASSERT(vp->v_mount->mnt_nvnodelistsize > 0, + ("bad mount point vnode list size")); + TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes); + vp->v_mount->mnt_nvnodelistsize--; + } + /* + * 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); + mp->mnt_nvnodelistsize++; + 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)) { + VI_LOCK(vp); + vp->v_numoutput--; + if (vp->v_numoutput < 0) + panic("vwakeup: neg numoutput"); + if ((vp->v_numoutput == 0) && (vp->v_iflag & VI_BWAIT)) { + vp->v_iflag &= ~VI_BWAIT; + wakeup(&vp->v_numoutput); + } + VI_UNLOCK(vp); + } +} + +/* + * Flush out and invalidate all buffers associated with a vnode. + * Called with the underlying object locked. + */ +int +vinvalbuf(vp, flags, cred, td, slpflag, slptimeo) + struct vnode *vp; + int flags; + struct ucred *cred; + struct thread *td; + int slpflag, slptimeo; +{ + struct buf *blist; + int s, error; + vm_object_t object; + + GIANT_REQUIRED; + + ASSERT_VOP_LOCKED(vp, "vinvalbuf"); + + VI_LOCK(vp); + if (flags & V_SAVE) { + s = splbio(); + while (vp->v_numoutput) { + vp->v_iflag |= VI_BWAIT; + error = msleep(&vp->v_numoutput, VI_MTX(vp), + slpflag | (PRIBIO + 1), "vinvlbuf", slptimeo); + if (error) { + VI_UNLOCK(vp); + splx(s); + return (error); + } + } + if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { + splx(s); + VI_UNLOCK(vp); + if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, td)) != 0) + return (error); + /* + * XXX We could save a lock/unlock if this was only + * enabled under INVARIANTS + */ + VI_LOCK(vp); + s = splbio(); + if (vp->v_numoutput > 0 || + !TAILQ_EMPTY(&vp->v_dirtyblkhd)) + panic("vinvalbuf: dirty bufs"); + } + splx(s); + } + s = splbio(); + /* + * If you alter this loop please notice that interlock is dropped and + * reacquired in flushbuflist. Special care is needed to ensure that + * no race conditions occur from this. + */ + for (error = 0;;) { + if ((blist = TAILQ_FIRST(&vp->v_cleanblkhd)) != 0 && + flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { + if (error) + break; + continue; + } + if ((blist = TAILQ_FIRST(&vp->v_dirtyblkhd)) != 0 && + flushbuflist(blist, flags, vp, slpflag, slptimeo, &error)) { + if (error) + break; + continue; + } + break; + } + if (error) { + splx(s); + VI_UNLOCK(vp); + return (error); + } + + /* + * Wait for I/O to complete. XXX needs cleaning up. The vnode can + * have write I/O in-progress but if there is a VM object then the + * VM object can also have read-I/O in-progress. + */ + do { + while (vp->v_numoutput > 0) { + vp->v_iflag |= VI_BWAIT; + msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vnvlbv", 0); + } + VI_UNLOCK(vp); + if (VOP_GETVOBJECT(vp, &object) == 0) { + VM_OBJECT_LOCK(object); + vm_object_pip_wait(object, "vnvlbx"); + VM_OBJECT_UNLOCK(object); + } + VI_LOCK(vp); + } while (vp->v_numoutput > 0); + VI_UNLOCK(vp); + + splx(s); + + /* + * Destroy the copy in the VM cache, too. + */ + if (VOP_GETVOBJECT(vp, &object) == 0) { + VM_OBJECT_LOCK(object); + vm_object_page_remove(object, 0, 0, + (flags & V_SAVE) ? TRUE : FALSE); + VM_OBJECT_UNLOCK(object); + } + +#ifdef INVARIANTS + VI_LOCK(vp); + if ((flags & (V_ALT | V_NORMAL)) == 0 && + (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || + !TAILQ_EMPTY(&vp->v_cleanblkhd))) + panic("vinvalbuf: flush failed"); + VI_UNLOCK(vp); +#endif + return (0); +} + +/* + * Flush out buffers on the specified list. + * + */ +static int +flushbuflist(blist, flags, vp, slpflag, slptimeo, errorp) + struct buf *blist; + int flags; + struct vnode *vp; + int slpflag, slptimeo; + int *errorp; +{ + struct buf *bp, *nbp; + int found, error; + + ASSERT_VI_LOCKED(vp, "flushbuflist"); + + for (found = 0, bp = blist; bp; bp = nbp) { + nbp = TAILQ_NEXT(bp, b_vnbufs); + if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) || + ((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) { + continue; + } + found += 1; + error = BUF_TIMELOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, VI_MTX(vp), + "flushbuf", slpflag, slptimeo); + if (error) { + if (error != ENOLCK) + *errorp = error; + goto done; + } + /* + * XXX Since there are no node locks for NFS, I + * believe there is a slight chance that a delayed + * write will occur while sleeping just above, so + * check for it. Note that vfs_bio_awrite expects + * buffers to reside on a queue, while BUF_WRITE and + * brelse do not. + */ + if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) && + (flags & V_SAVE)) { + + if (bp->b_vp == vp) { + if (bp->b_flags & B_CLUSTEROK) { + vfs_bio_awrite(bp); + } else { + bremfree(bp); + bp->b_flags |= B_ASYNC; + BUF_WRITE(bp); + } + } else { + bremfree(bp); + (void) BUF_WRITE(bp); + } + goto done; + } + bremfree(bp); + bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF); + bp->b_flags &= ~B_ASYNC; + brelse(bp); + VI_LOCK(vp); + } + return (found); +done: + VI_LOCK(vp); + return (found); +} + +/* + * Truncate a file's buffer and pages to a specified length. This + * is in lieu of the old vinvalbuf mechanism, which performed unneeded + * sync activity. + */ +int +vtruncbuf(vp, cred, td, length, blksize) + register struct vnode *vp; + struct ucred *cred; + struct thread *td; + off_t length; + int blksize; +{ + register struct buf *bp; + struct buf *nbp; + int s, anyfreed; + int trunclbn; + + /* + * Round up to the *next* lbn. + */ + trunclbn = (length + blksize - 1) / blksize; + + s = splbio(); + ASSERT_VOP_LOCKED(vp, "vtruncbuf"); +restart: + VI_LOCK(vp); + anyfreed = 1; + for (;anyfreed;) { + anyfreed = 0; + for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) { + nbp = TAILQ_NEXT(bp, b_vnbufs); + if (bp->b_lblkno >= trunclbn) { + if (BUF_LOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, + VI_MTX(vp)) == ENOLCK) + goto restart; + + bremfree(bp); + bp->b_flags |= (B_INVAL | B_RELBUF); + bp->b_flags &= ~B_ASYNC; + brelse(bp); + anyfreed = 1; + + if (nbp && + (((nbp->b_xflags & BX_VNCLEAN) == 0) || + (nbp->b_vp != vp) || + (nbp->b_flags & B_DELWRI))) { + goto restart; + } + VI_LOCK(vp); + } + } + + for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { + nbp = TAILQ_NEXT(bp, b_vnbufs); + if (bp->b_lblkno >= trunclbn) { + if (BUF_LOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, + VI_MTX(vp)) == ENOLCK) + goto restart; + bremfree(bp); + bp->b_flags |= (B_INVAL | B_RELBUF); + bp->b_flags &= ~B_ASYNC; + brelse(bp); + anyfreed = 1; + if (nbp && + (((nbp->b_xflags & BX_VNDIRTY) == 0) || + (nbp->b_vp != vp) || + (nbp->b_flags & B_DELWRI) == 0)) { + goto restart; + } + VI_LOCK(vp); + } + } + } + + if (length > 0) { +restartsync: + for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { + nbp = TAILQ_NEXT(bp, b_vnbufs); + if (bp->b_lblkno > 0) + continue; + /* + * Since we hold the vnode lock this should only + * fail if we're racing with the buf daemon. + */ + if (BUF_LOCK(bp, + LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, + VI_MTX(vp)) == ENOLCK) { + goto restart; + } + KASSERT((bp->b_flags & B_DELWRI), + ("buf(%p) on dirty queue without DELWRI.", bp)); + + bremfree(bp); + bawrite(bp); + VI_LOCK(vp); + goto restartsync; + } + } + + while (vp->v_numoutput > 0) { + vp->v_iflag |= VI_BWAIT; + msleep(&vp->v_numoutput, VI_MTX(vp), PVM, "vbtrunc", 0); + } + VI_UNLOCK(vp); + splx(s); + + vnode_pager_setsize(vp, length); + + return (0); +} + +/* + * buf_splay() - splay tree core for the clean/dirty list of buffers in + * a vnode. + * + * NOTE: We have to deal with the special case of a background bitmap + * buffer, a situation where two buffers will have the same logical + * block offset. We want (1) only the foreground buffer to be accessed + * in a lookup and (2) must differentiate between the foreground and + * background buffer in the splay tree algorithm because the splay + * tree cannot normally handle multiple entities with the same 'index'. + * We accomplish this by adding differentiating flags to the splay tree's + * numerical domain. + */ +static +struct buf * +buf_splay(daddr_t lblkno, b_xflags_t xflags, struct buf *root) +{ + struct buf dummy; + struct buf *lefttreemax, *righttreemin, *y; + + if (root == NULL) + return (NULL); + lefttreemax = righttreemin = &dummy; + for (;;) { + if (lblkno < root->b_lblkno || + (lblkno == root->b_lblkno && + (xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { + if ((y = root->b_left) == NULL) + break; + if (lblkno < y->b_lblkno) { + /* Rotate right. */ + root->b_left = y->b_right; + y->b_right = root; + root = y; + if ((y = root->b_left) == NULL) + break; + } + /* Link into the new root's right tree. */ + righttreemin->b_left = root; + righttreemin = root; + } else if (lblkno > root->b_lblkno || + (lblkno == root->b_lblkno && + (xflags & BX_BKGRDMARKER) > (root->b_xflags & BX_BKGRDMARKER))) { + if ((y = root->b_right) == NULL) + break; + if (lblkno > y->b_lblkno) { + /* Rotate left. */ + root->b_right = y->b_left; + y->b_left = root; + root = y; + if ((y = root->b_right) == NULL) + break; + } + /* Link into the new root's left tree. */ + lefttreemax->b_right = root; + lefttreemax = root; + } else { + break; + } + root = y; + } + /* Assemble the new root. */ + lefttreemax->b_right = root->b_left; + righttreemin->b_left = root->b_right; + root->b_left = dummy.b_right; + root->b_right = dummy.b_left; + return (root); +} + +static +void +buf_vlist_remove(struct buf *bp) +{ + struct vnode *vp = bp->b_vp; + struct buf *root; + + ASSERT_VI_LOCKED(vp, "buf_vlist_remove"); + if (bp->b_xflags & BX_VNDIRTY) { + if (bp != vp->v_dirtyblkroot) { + root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); + KASSERT(root == bp, ("splay lookup failed during dirty remove")); + } + if (bp->b_left == NULL) { + root = bp->b_right; + } else { + root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); + root->b_right = bp->b_right; + } + vp->v_dirtyblkroot = root; + TAILQ_REMOVE(&vp->v_dirtyblkhd, bp, b_vnbufs); + vp->v_dirtybufcnt--; + } else { + /* KASSERT(bp->b_xflags & BX_VNCLEAN, ("bp wasn't clean")); */ + if (bp != vp->v_cleanblkroot) { + root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); + KASSERT(root == bp, ("splay lookup failed during clean remove")); + } + if (bp->b_left == NULL) { + root = bp->b_right; + } else { + root = buf_splay(bp->b_lblkno, bp->b_xflags, bp->b_left); + root->b_right = bp->b_right; + } + vp->v_cleanblkroot = root; + TAILQ_REMOVE(&vp->v_cleanblkhd, bp, b_vnbufs); + vp->v_cleanbufcnt--; + } + bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN); +} + +/* + * Add the buffer to the sorted clean or dirty block list using a + * splay tree algorithm. + * + * NOTE: xflags is passed as a constant, optimizing this inline function! + */ +static +void +buf_vlist_add(struct buf *bp, struct vnode *vp, b_xflags_t xflags) +{ + struct buf *root; + + ASSERT_VI_LOCKED(vp, "buf_vlist_add"); + bp->b_xflags |= xflags; + if (xflags & BX_VNDIRTY) { + root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_dirtyblkroot); + if (root == NULL) { + bp->b_left = NULL; + bp->b_right = NULL; + TAILQ_INSERT_TAIL(&vp->v_dirtyblkhd, bp, b_vnbufs); + } else if (bp->b_lblkno < root->b_lblkno || + (bp->b_lblkno == root->b_lblkno && + (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { + bp->b_left = root->b_left; + bp->b_right = root; + root->b_left = NULL; + TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); + } else { + bp->b_right = root->b_right; + bp->b_left = root; + root->b_right = NULL; + TAILQ_INSERT_AFTER(&vp->v_dirtyblkhd, + root, bp, b_vnbufs); + } + vp->v_dirtybufcnt++; + vp->v_dirtyblkroot = bp; + } else { + /* KASSERT(xflags & BX_VNCLEAN, ("xflags not clean")); */ + root = buf_splay(bp->b_lblkno, bp->b_xflags, vp->v_cleanblkroot); + if (root == NULL) { + bp->b_left = NULL; + bp->b_right = NULL; + TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs); + } else if (bp->b_lblkno < root->b_lblkno || + (bp->b_lblkno == root->b_lblkno && + (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags & BX_BKGRDMARKER))) { + bp->b_left = root->b_left; + bp->b_right = root; + root->b_left = NULL; + TAILQ_INSERT_BEFORE(root, bp, b_vnbufs); + } else { + bp->b_right = root->b_right; + bp->b_left = root; + root->b_right = NULL; + TAILQ_INSERT_AFTER(&vp->v_cleanblkhd, + root, bp, b_vnbufs); + } + vp->v_cleanbufcnt++; + vp->v_cleanblkroot = bp; + } +} + +/* + * Lookup a buffer using the splay tree. Note that we specifically avoid + * shadow buffers used in background bitmap writes. + * + * This code isn't quite efficient as it could be because we are maintaining + * two sorted lists and do not know which list the block resides in. + * + * During a "make buildworld" the desired buffer is found at one of + * the roots more than 60% of the time. Thus, checking both roots + * before performing either splay eliminates unnecessary splays on the + * first tree splayed. + */ +struct buf * +gbincore(struct vnode *vp, daddr_t lblkno) +{ + struct buf *bp; + + GIANT_REQUIRED; + + ASSERT_VI_LOCKED(vp, "gbincore"); + if ((bp = vp->v_cleanblkroot) != NULL && + bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) + return (bp); + if ((bp = vp->v_dirtyblkroot) != NULL && + bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) + return (bp); + if ((bp = vp->v_cleanblkroot) != NULL) { + vp->v_cleanblkroot = bp = buf_splay(lblkno, 0, bp); + if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) + return (bp); + } + if ((bp = vp->v_dirtyblkroot) != NULL) { + vp->v_dirtyblkroot = bp = buf_splay(lblkno, 0, bp); + if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER)) + return (bp); + } + return (NULL); +} + +/* + * Associate a buffer with a vnode. + */ +void +bgetvp(vp, bp) + register struct vnode *vp; + register struct buf *bp; +{ + int s; + + KASSERT(bp->b_vp == NULL, ("bgetvp: not free")); + + KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, + ("bgetvp: bp already attached! %p", bp)); + + ASSERT_VI_LOCKED(vp, "bgetvp"); + vholdl(vp); + bp->b_vp = vp; + bp->b_dev = vn_todev(vp); + /* + * Insert onto list for new vnode. + */ + s = splbio(); + buf_vlist_add(bp, vp, BX_VNCLEAN); + splx(s); +} + +/* + * Disassociate a buffer from a vnode. + */ +void +brelvp(bp) + register struct buf *bp; +{ + struct vnode *vp; + int s; + + KASSERT(bp->b_vp != NULL, ("brelvp: NULL")); + + /* + * Delete from old vnode list, if on one. + */ + vp = bp->b_vp; + s = splbio(); + VI_LOCK(vp); + if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) + buf_vlist_remove(bp); + if ((vp->v_iflag & VI_ONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) { + vp->v_iflag &= ~VI_ONWORKLST; + mtx_lock(&sync_mtx); + LIST_REMOVE(vp, v_synclist); + mtx_unlock(&sync_mtx); + } + vdropl(vp); + VI_UNLOCK(vp); + bp->b_vp = (struct vnode *) 0; + if (bp->b_object) + bp->b_object = NULL; + splx(s); +} + +/* + * 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(); + ASSERT_VI_LOCKED(vp, "vn_syncer_add_to_worklist"); + + mtx_lock(&sync_mtx); + if (vp->v_iflag & VI_ONWORKLST) + LIST_REMOVE(vp, v_synclist); + else + vp->v_iflag |= VI_ONWORKLST; + + if (delay > syncer_maxdelay - 2) + delay = syncer_maxdelay - 2; + slot = (syncer_delayno + delay) & syncer_mask; + + LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist); + mtx_unlock(&sync_mtx); + + splx(s); +} + +struct proc *updateproc; +static void sched_sync(void); +static struct kproc_desc up_kp = { + "syncer", + sched_sync, + &updateproc +}; +SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp) + +/* + * System filesystem synchronizer daemon. + */ +static void +sched_sync(void) +{ + struct synclist *slp; + struct vnode *vp; + struct mount *mp; + long starttime; + int s; + struct thread *td = FIRST_THREAD_IN_PROC(updateproc); /* XXXKSE */ + + mtx_lock(&Giant); + + EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, td->td_proc, + SHUTDOWN_PRI_LAST); + + for (;;) { + kthread_suspend_check(td->td_proc); + + starttime = time_second; + + /* + * Push files whose dirty time has expired. Be careful + * of interrupt race on slp queue. + */ + s = splbio(); + mtx_lock(&sync_mtx); + 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) { + mtx_unlock(&sync_mtx); + 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_ucred, MNT_LAZY, td); + VOP_UNLOCK(vp, 0, td); + vn_finished_write(mp); + } + s = splbio(); + mtx_lock(&sync_mtx); + if (LIST_FIRST(slp) == vp) { + mtx_unlock(&sync_mtx); + /* + * Note: VFS vnodes can remain on the + * worklist too with no dirty blocks, but + * since sync_fsync() moves it to a different + * slot we are safe. + */ + VI_LOCK(vp); + if (TAILQ_EMPTY(&vp->v_dirtyblkhd) && + !vn_isdisk(vp, NULL)) { + panic("sched_sync: fsync failed " + "vp %p tag %s", 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); + VI_UNLOCK(vp); + mtx_lock(&sync_mtx); + } + splx(s); + } + mtx_unlock(&sync_mtx); + + /* + * Do soft update processing. + */ + if (softdep_process_worklist_hook != NULL) + (*softdep_process_worklist_hook)(NULL); + + /* + * The variable rushjob allows the kernel to speed up the + * processing of the filesystem syncer process. A rushjob + * value of N tells the filesystem syncer to process the next + * N seconds worth of work on its queue ASAP. Currently rushjob + * is used by the soft update code to speed up the filesystem + * syncer process when the incore state is getting so far + * ahead of the disk that the kernel memory pool is being + * threatened with exhaustion. + */ + mtx_lock(&sync_mtx); + if (rushjob > 0) { + rushjob -= 1; + mtx_unlock(&sync_mtx); + continue; + } + mtx_unlock(&sync_mtx); + /* + * If it has taken us less than a second to process the + * current work, then wait. Otherwise start right over + * again. We can still lose time if any single round + * takes more than two seconds, but it does not really + * matter as we are just trying to generally pace the + * filesystem activity. + */ + if (time_second == starttime) + tsleep(&lbolt, PPAUSE, "syncer", 0); + } +} + +/* + * Request the syncer daemon to speed up its work. + * We never push it to speed up more than half of its + * normal turn time, otherwise it could take over the cpu. + * XXXKSE only one update? + */ +int +speedup_syncer() +{ + struct thread *td; + int ret = 0; + + td = FIRST_THREAD_IN_PROC(updateproc); + mtx_lock_spin(&sched_lock); + if (td->td_wchan == &lbolt) { + unsleep(td); + TD_CLR_SLEEPING(td); + setrunnable(td); + } + mtx_unlock_spin(&sched_lock); + mtx_lock(&sync_mtx); + if (rushjob < syncdelay / 2) { + rushjob += 1; + stat_rush_requests += 1; + ret = 1; + } + mtx_unlock(&sync_mtx); + return (ret); +} + +/* + * Associate a p-buffer with a vnode. + * + * Also sets B_PAGING flag to indicate that vnode is not fully associated + * with the buffer. i.e. the bp has not been linked into the vnode or + * ref-counted. + */ +void +pbgetvp(vp, bp) + register struct vnode *vp; + register struct buf *bp; +{ + + KASSERT(bp->b_vp == NULL, ("pbgetvp: not free")); + + bp->b_vp = vp; + bp->b_flags |= B_PAGING; + bp->b_dev = vn_todev(vp); +} + +/* + * Disassociate a p-buffer from a vnode. + */ +void +pbrelvp(bp) + register struct buf *bp; +{ + + KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL")); + + /* XXX REMOVE ME */ + VI_LOCK(bp->b_vp); + if (TAILQ_NEXT(bp, b_vnbufs) != NULL) { + panic( + "relpbuf(): b_vp was probably reassignbuf()d %p %x", + bp, + (int)bp->b_flags + ); + } + VI_UNLOCK(bp->b_vp); + bp->b_vp = (struct vnode *) 0; + bp->b_flags &= ~B_PAGING; +} + +/* + * Reassign a buffer from one vnode to another. + * Used to assign file specific control information + * (indirect blocks) to the vnode to which they belong. + */ +void +reassignbuf(bp, newvp) + register struct buf *bp; + register struct vnode *newvp; +{ + 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. + */ + VI_LOCK(bp->b_vp); + if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) { + buf_vlist_remove(bp); + if (bp->b_vp != newvp) { + vdropl(bp->b_vp); + bp->b_vp = NULL; /* for clarification */ + } + } + VI_UNLOCK(bp->b_vp); + /* + * If dirty, put on list of dirty buffers; otherwise insert onto list + * of clean buffers. + */ + VI_LOCK(newvp); + if (bp->b_flags & B_DELWRI) { + if ((newvp->v_iflag & VI_ONWORKLST) == 0) { + switch (newvp->v_type) { + case VDIR: + delay = dirdelay; + break; + case VCHR: + if (newvp->v_rdev->si_mountpoint != NULL) { + delay = metadelay; + break; + } + /* FALLTHROUGH */ + default: + delay = filedelay; + } + vn_syncer_add_to_worklist(newvp, delay); + } + buf_vlist_add(bp, newvp, BX_VNDIRTY); + } else { + buf_vlist_add(bp, newvp, BX_VNCLEAN); + + if ((newvp->v_iflag & VI_ONWORKLST) && + TAILQ_EMPTY(&newvp->v_dirtyblkhd)) { + mtx_lock(&sync_mtx); + LIST_REMOVE(newvp, v_synclist); + mtx_unlock(&sync_mtx); + newvp->v_iflag &= ~VI_ONWORKLST; + } + } + if (bp->b_vp != newvp) { + bp->b_vp = newvp; + vholdl(bp->b_vp); + } + VI_UNLOCK(newvp); + splx(s); +} + +/* + * Create a vnode for a device. + * Used for mounting the root filesystem. + */ +int +bdevvp(dev, vpp) + dev_t dev; + struct vnode **vpp; +{ + register struct vnode *vp; + struct vnode *nvp; + int error; + + if (dev == NODEV) { + *vpp = NULLVP; + return (ENXIO); + } + if (vfinddev(dev, VCHR, vpp)) + return (0); + error = getnewvnode("none", (struct mount *)0, spec_vnodeop_p, &nvp); + if (error) { + *vpp = NULLVP; + return (error); + } + vp = nvp; + vp->v_type = VCHR; + addalias(vp, dev); + *vpp = vp; + return (0); +} + +static void +v_incr_usecount(struct vnode *vp, int delta) +{ + vp->v_usecount += delta; + if (vp->v_type == VCHR && vp->v_rdev != NULL) { + mtx_lock(&spechash_mtx); + vp->v_rdev->si_usecount += delta; + mtx_unlock(&spechash_mtx); + } +} + +/* + * Add vnode to the alias list hung off the dev_t. + * + * The reason for this gunk is that multiple vnodes can reference + * the same physical device, so checking vp->v_usecount to see + * how many users there are is inadequate; the v_usecount for + * the vnodes need to be accumulated. vcount() does that. + */ +struct vnode * +addaliasu(nvp, nvp_rdev) + struct vnode *nvp; + udev_t nvp_rdev; +{ + struct vnode *ovp; + vop_t **ops; + dev_t dev; + + if (nvp->v_type == VBLK) + return (nvp); + if (nvp->v_type != VCHR) + panic("addaliasu on non-special vnode"); + dev = udev2dev(nvp_rdev, 0); + /* + * Check to see if we have a bdevvp vnode with no associated + * filesystem. If so, we want to associate the filesystem of + * the new newly instigated vnode with the bdevvp vnode and + * discard the newly created vnode rather than leaving the + * bdevvp vnode lying around with no associated filesystem. + */ + if (vfinddev(dev, nvp->v_type, &ovp) == 0 || ovp->v_data != NULL) { + addalias(nvp, dev); + return (nvp); + } + /* + * Discard unneeded vnode, but save its node specific data. + * Note that if there is a lock, it is carried over in the + * node specific data to the replacement vnode. + */ + vref(ovp); + ovp->v_data = nvp->v_data; + ovp->v_tag = nvp->v_tag; + nvp->v_data = NULL; + lockdestroy(ovp->v_vnlock); + lockinit(ovp->v_vnlock, PVFS, nvp->v_vnlock->lk_wmesg, + nvp->v_vnlock->lk_timo, nvp->v_vnlock->lk_flags & LK_EXTFLG_MASK); + ops = ovp->v_op; + ovp->v_op = nvp->v_op; + if (VOP_ISLOCKED(nvp, curthread)) { + VOP_UNLOCK(nvp, 0, curthread); + vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, curthread); + } + nvp->v_op = ops; + insmntque(ovp, nvp->v_mount); + vrele(nvp); + vgone(nvp); + return (ovp); +} + +/* This is a local helper function that do the same as addaliasu, but for a + * dev_t instead of an udev_t. */ +static void +addalias(nvp, dev) + struct vnode *nvp; + dev_t dev; +{ + + KASSERT(nvp->v_type == VCHR, ("addalias on non-special vnode")); + nvp->v_rdev = dev; + VI_LOCK(nvp); + mtx_lock(&spechash_mtx); + SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext); + dev->si_usecount += nvp->v_usecount; + mtx_unlock(&spechash_mtx); + VI_UNLOCK(nvp); +} + +/* + * Grab a particular vnode from the free list, increment its + * reference count and lock it. The vnode lock bit is set if the + * vnode is being eliminated in vgone. The process is awakened + * when the transition is completed, and an error returned to + * indicate that the vnode is no longer usable (possibly having + * been changed to a new filesystem type). + */ +int +vget(vp, flags, td) + register struct vnode *vp; + int flags; + struct thread *td; +{ + int error; + + /* + * If the vnode is in the process of being cleaned out for + * another use, we wait for the cleaning to finish and then + * return failure. Cleaning is determined by checking that + * the VI_XLOCK flag is set. + */ + if ((flags & LK_INTERLOCK) == 0) + VI_LOCK(vp); + if (vp->v_iflag & VI_XLOCK && vp->v_vxproc != curthread) { + vp->v_iflag |= VI_XWANT; + msleep(vp, VI_MTX(vp), PINOD | PDROP, "vget", 0); + return (ENOENT); + } + + v_incr_usecount(vp, 1); + + if (VSHOULDBUSY(vp)) + vbusy(vp); + if (flags & LK_TYPE_MASK) { + if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) { + /* + * must expand vrele here because we do not want + * to call VOP_INACTIVE if the reference count + * drops back to zero since it was never really + * active. We must remove it from the free list + * before sleeping so that multiple processes do + * not try to recycle it. + */ + VI_LOCK(vp); + v_incr_usecount(vp, -1); + if (VSHOULDFREE(vp)) + vfree(vp); + else + vlruvp(vp); + VI_UNLOCK(vp); + } + return (error); + } + VI_UNLOCK(vp); + return (0); +} + +/* + * Increase the reference count of a vnode. + */ +void +vref(struct vnode *vp) +{ + VI_LOCK(vp); + v_incr_usecount(vp, 1); + VI_UNLOCK(vp); +} + +/* + * Return reference count of a vnode. + * + * The results of this call are only guaranteed when some mechanism other + * than the VI lock is used to stop other processes from gaining references + * to the vnode. This may be the case if the caller holds the only reference. + * This is also useful when stale data is acceptable as race conditions may + * be accounted for by some other means. + */ +int +vrefcnt(struct vnode *vp) +{ + int usecnt; + + VI_LOCK(vp); + usecnt = vp->v_usecount; + VI_UNLOCK(vp); + + return (usecnt); +} + + +/* + * Vnode put/release. + * If count drops to zero, call inactive routine and return to freelist. + */ +void +vrele(vp) + struct vnode *vp; +{ + struct thread *td = curthread; /* XXX */ + + KASSERT(vp != NULL, ("vrele: null vp")); + + VI_LOCK(vp); + + /* Skip this v_writecount check if we're going to panic below. */ + KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, + ("vrele: missed vn_close")); + + if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && + vp->v_usecount == 1)) { + v_incr_usecount(vp, -1); + VI_UNLOCK(vp); + + return; + } + + if (vp->v_usecount == 1) { + v_incr_usecount(vp, -1); + /* + * We must call VOP_INACTIVE with the node locked. Mark + * as VI_DOINGINACT to avoid recursion. + */ + if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0) { + VI_LOCK(vp); + vp->v_iflag |= VI_DOINGINACT; + VI_UNLOCK(vp); + VOP_INACTIVE(vp, td); + VI_LOCK(vp); + KASSERT(vp->v_iflag & VI_DOINGINACT, + ("vrele: lost VI_DOINGINACT")); + vp->v_iflag &= ~VI_DOINGINACT; + VI_UNLOCK(vp); + } + VI_LOCK(vp); + if (VSHOULDFREE(vp)) + vfree(vp); + else + vlruvp(vp); + VI_UNLOCK(vp); + + } else { +#ifdef DIAGNOSTIC + vprint("vrele: negative ref count", vp); +#endif + VI_UNLOCK(vp); + panic("vrele: negative ref cnt"); + } +} + +/* + * Release an already locked vnode. This give the same effects as + * unlock+vrele(), but takes less time and avoids releasing and + * re-aquiring the lock (as vrele() aquires the lock internally.) + */ +void +vput(vp) + struct vnode *vp; +{ + struct thread *td = curthread; /* XXX */ + + GIANT_REQUIRED; + + KASSERT(vp != NULL, ("vput: null vp")); + VI_LOCK(vp); + /* Skip this v_writecount check if we're going to panic below. */ + KASSERT(vp->v_writecount < vp->v_usecount || vp->v_usecount < 1, + ("vput: missed vn_close")); + + if (vp->v_usecount > 1 || ((vp->v_iflag & VI_DOINGINACT) && + vp->v_usecount == 1)) { + v_incr_usecount(vp, -1); + VOP_UNLOCK(vp, LK_INTERLOCK, td); + return; + } + + if (vp->v_usecount == 1) { + v_incr_usecount(vp, -1); + /* + * We must call VOP_INACTIVE with the node locked, so + * we just need to release the vnode mutex. Mark as + * as VI_DOINGINACT to avoid recursion. + */ + vp->v_iflag |= VI_DOINGINACT; + VI_UNLOCK(vp); + VOP_INACTIVE(vp, td); + VI_LOCK(vp); + KASSERT(vp->v_iflag & VI_DOINGINACT, + ("vput: lost VI_DOINGINACT")); + vp->v_iflag &= ~VI_DOINGINACT; + if (VSHOULDFREE(vp)) + vfree(vp); + else + vlruvp(vp); + VI_UNLOCK(vp); + + } else { +#ifdef DIAGNOSTIC + vprint("vput: negative ref count", vp); +#endif + panic("vput: negative ref cnt"); + } +} + +/* + * Somebody doesn't want the vnode recycled. + */ +void +vhold(struct vnode *vp) +{ + VI_LOCK(vp); + vholdl(vp); + VI_UNLOCK(vp); +} + +void +vholdl(vp) + register struct vnode *vp; +{ + 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(struct vnode *vp) +{ + VI_LOCK(vp); + vdropl(vp); + VI_UNLOCK(vp); +} + +void +vdropl(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); + else + vlruvp(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 VV_SYSTEM to be skipped. + * + * `rootrefs' specifies the base reference count for the root vnode + * of this filesystem. The root vnode is considered busy if its + * v_usecount exceeds this value. On a successful return, vflush() + * will call vrele() on the root vnode exactly rootrefs times. + * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must + * be zero. + */ +#ifdef DIAGNOSTIC +static int busyprt = 0; /* print out busy vnodes */ +SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, ""); +#endif + +int +vflush(mp, rootrefs, flags) + struct mount *mp; + int rootrefs; + int flags; +{ + struct thread *td = curthread; /* XXX */ + struct vnode *vp, *nvp, *rootvp = NULL; + struct vattr vattr; + int busy = 0, error; + + if (rootrefs > 0) { + KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0, + ("vflush: bad args")); + /* + * Get the filesystem root vnode. We can vput() it + * immediately, since with rootrefs > 0, it won't go away. + */ + if ((error = VFS_ROOT(mp, &rootvp)) != 0) + return (error); + vput(rootvp); + + } + 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); + + VI_LOCK(vp); + mtx_unlock(&mntvnode_mtx); + vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY, td); + /* + * This vnode could have been reclaimed while we were + * waiting for the lock since we are not holding a + * reference. + * Start over if the vnode was reclaimed. + */ + if (vp->v_mount != mp) { + VOP_UNLOCK(vp, 0, td); + mtx_lock(&mntvnode_mtx); + goto loop; + } + /* + * Skip over a vnodes marked VV_SYSTEM. + */ + if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) { + VOP_UNLOCK(vp, 0, td); + mtx_lock(&mntvnode_mtx); + continue; + } + /* + * If WRITECLOSE is set, flush out unlinked but still open + * files (even if open only for reading) and regular file + * vnodes open for writing. + */ + if (flags & WRITECLOSE) { + error = VOP_GETATTR(vp, &vattr, td->td_ucred, td); + VI_LOCK(vp); + + if ((vp->v_type == VNON || + (error == 0 && vattr.va_nlink > 0)) && + (vp->v_writecount == 0 || vp->v_type != VREG)) { + VOP_UNLOCK(vp, LK_INTERLOCK, td); + mtx_lock(&mntvnode_mtx); + continue; + } + } else + VI_LOCK(vp); + + VOP_UNLOCK(vp, 0, td); + + /* + * With v_usecount == 0, all we need to do is clear out the + * vnode data structures and we are done. + */ + if (vp->v_usecount == 0) { + vgonel(vp, td); + 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); + VI_UNLOCK(vp); + 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 + VI_UNLOCK(vp); + 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. + */ + VI_LOCK(rootvp); + KASSERT(busy > 0, ("vflush: not busy")); + KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs")); + if (busy == 1 && rootvp->v_usecount == rootrefs) { + vgonel(rootvp, td); + busy = 0; + } else + VI_UNLOCK(rootvp); + } + if (busy) + return (EBUSY); + for (; rootrefs > 0; rootrefs--) + vrele(rootvp); + return (0); +} + +/* + * This moves a now (likely recyclable) vnode to the end of the + * mountlist. XXX However, it is temporarily disabled until we + * can clean up ffs_sync() and friends, which have loop restart + * conditions which this code causes to operate O(N^2). + */ +static void +vlruvp(struct vnode *vp) +{ +#if 0 + struct mount *mp; + + if ((mp = vp->v_mount) != NULL) { + mtx_lock(&mntvnode_mtx); + TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes); + mtx_unlock(&mntvnode_mtx); + } +#endif +} + +/* + * Disassociate the underlying filesystem from a vnode. + */ +static void +vclean(vp, flags, td) + struct vnode *vp; + int flags; + struct thread *td; +{ + int active; + + ASSERT_VI_LOCKED(vp, "vclean"); + /* + * Check to see if the vnode is in use. If so we have to reference it + * before we clean it out so that its count cannot fall to zero and + * generate a race against ourselves to recycle it. + */ + if ((active = vp->v_usecount)) + v_incr_usecount(vp, 1); + + /* + * Prevent the vnode from being recycled or brought into use while we + * clean it out. + */ + if (vp->v_iflag & VI_XLOCK) + panic("vclean: deadlock"); + vp->v_iflag |= VI_XLOCK; + vp->v_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) { + struct buf *bp; + VI_LOCK(vp); + bp = TAILQ_FIRST(&vp->v_dirtyblkhd); + VI_UNLOCK(vp); + if (bp != NULL) + (void) vn_write_suspend_wait(vp, NULL, V_WAIT); + if (vinvalbuf(vp, V_SAVE, NOCRED, td, 0, 0) != 0) + vinvalbuf(vp, 0, NOCRED, td, 0, 0); + } + + VOP_DESTROYVOBJECT(vp); + + /* + * Any other processes trying to obtain this lock must first + * wait for VXLOCK to clear, then call the new lock operation. + */ + VOP_UNLOCK(vp, 0, td); + + /* + * If purging an active vnode, it must be closed and + * deactivated before being reclaimed. Note that the + * VOP_INACTIVE will unlock the vnode. + */ + if (active) { + if (flags & DOCLOSE) + VOP_CLOSE(vp, FNONBLOCK, NOCRED, td); + VI_LOCK(vp); + if ((vp->v_iflag & VI_DOINGINACT) == 0) { + vp->v_iflag |= VI_DOINGINACT; + VI_UNLOCK(vp); + if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT, td) != 0) + panic("vclean: cannot relock."); + VOP_INACTIVE(vp, td); + VI_LOCK(vp); + KASSERT(vp->v_iflag & VI_DOINGINACT, + ("vclean: lost VI_DOINGINACT")); + vp->v_iflag &= ~VI_DOINGINACT; + } + VI_UNLOCK(vp); + } + + /* + * Reclaim the vnode. + */ + if (VOP_RECLAIM(vp, td)) + panic("vclean: cannot reclaim"); + + if (active) { + /* + * Inline copy of vrele() since VOP_INACTIVE + * has already been called. + */ + VI_LOCK(vp); + v_incr_usecount(vp, -1); + if (vp->v_usecount <= 0) { +#ifdef DIAGNOSTIC + if (vp->v_usecount < 0 || vp->v_writecount != 0) { + vprint("vclean: bad ref count", vp); + panic("vclean: ref cnt"); + } +#endif + vfree(vp); + } + VI_UNLOCK(vp); + } + + cache_purge(vp); + VI_LOCK(vp); + if (VSHOULDFREE(vp)) + vfree(vp); + + /* + * Done with purge, reset to the standard lock and + * notify sleepers of the grim news. + */ + vp->v_vnlock = &vp->v_lock; + vp->v_op = dead_vnodeop_p; + if (vp->v_pollinfo != NULL) + vn_pollgone(vp); + vp->v_tag = "none"; + vp->v_iflag &= ~VI_XLOCK; + vp->v_vxproc = NULL; + if (vp->v_iflag & VI_XWANT) { + vp->v_iflag &= ~VI_XWANT; + wakeup(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; + KASSERT((vp->v_type == VCHR), ("vop_revoke: not VCHR")); + + VI_LOCK(vp); + /* + * If a vgone (or vclean) is already in progress, + * wait until it is done and return. + */ + if (vp->v_iflag & VI_XLOCK) { + vp->v_iflag |= VI_XWANT; + msleep(vp, VI_MTX(vp), PINOD | PDROP, + "vop_revokeall", 0); + return (0); + } + VI_UNLOCK(vp); + dev = vp->v_rdev; + for (;;) { + mtx_lock(&spechash_mtx); + vq = SLIST_FIRST(&dev->si_hlist); + mtx_unlock(&spechash_mtx); + if (!vq) + break; + vgone(vq); + } + return (0); +} + +/* + * Recycle an unused vnode to the front of the free list. + * Release the passed interlock if the vnode will be recycled. + */ +int +vrecycle(vp, inter_lkp, td) + struct vnode *vp; + struct mtx *inter_lkp; + struct thread *td; +{ + + VI_LOCK(vp); + if (vp->v_usecount == 0) { + if (inter_lkp) { + mtx_unlock(inter_lkp); + } + vgonel(vp, td); + return (1); + } + VI_UNLOCK(vp); + return (0); +} + +/* + * Eliminate all activity associated with a vnode + * in preparation for reuse. + */ +void +vgone(vp) + register struct vnode *vp; +{ + struct thread *td = curthread; /* XXX */ + + VI_LOCK(vp); + vgonel(vp, td); +} + +/* + * 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. + */ + ASSERT_VI_LOCKED(vp, "vgonel"); + if (vp->v_iflag & VI_XLOCK) { + vp->v_iflag |= VI_XWANT; + msleep(vp, VI_MTX(vp), PINOD | PDROP, "vgone", 0); + return; + } + + /* + * Clean out the filesystem specific data. + */ + vclean(vp, DOCLOSE, td); + VI_UNLOCK(vp); + + /* + * 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) { + VI_LOCK(vp); + mtx_lock(&spechash_mtx); + SLIST_REMOVE(&vp->v_rdev->si_hlist, vp, vnode, v_specnext); + vp->v_rdev->si_usecount -= vp->v_usecount; + mtx_unlock(&spechash_mtx); + VI_UNLOCK(vp); + 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. + */ + VI_LOCK(vp); + if (vp->v_usecount == 0 && !(vp->v_iflag & VI_DOOMED)) { + s = splbio(); + mtx_lock(&vnode_free_list_mtx); + if (vp->v_iflag & VI_FREE) { + TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); + } else { + vp->v_iflag |= VI_FREE; + freevnodes++; + } + TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); + mtx_unlock(&vnode_free_list_mtx); + splx(s); + } + + vp->v_type = VBAD; + VI_UNLOCK(vp); +} + +/* + * Lookup a vnode by device number. + */ +int +vfinddev(dev, type, vpp) + dev_t dev; + enum vtype type; + struct vnode **vpp; +{ + struct vnode *vp; + + mtx_lock(&spechash_mtx); + SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) { + if (type == vp->v_type) { + *vpp = vp; + mtx_unlock(&spechash_mtx); + return (1); + } + } + mtx_unlock(&spechash_mtx); + return (0); +} + +/* + * Calculate the total number of references to a special device. + */ +int +vcount(vp) + struct vnode *vp; +{ + int count; + + mtx_lock(&spechash_mtx); + count = vp->v_rdev->si_usecount; + mtx_unlock(&spechash_mtx); + return (count); +} + +/* + * Same as above, but using the dev_t as argument + */ +int +count_dev(dev) + dev_t dev; +{ + 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("tag %s, type %s, usecount %d, writecount %d, refcount %d,", + vp->v_tag, typename[vp->v_type], vp->v_usecount, + vp->v_writecount, vp->v_holdcnt); + buf[0] = '\0'; + if (vp->v_vflag & VV_ROOT) + strcat(buf, "|VV_ROOT"); + if (vp->v_vflag & VV_TEXT) + strcat(buf, "|VV_TEXT"); + if (vp->v_vflag & VV_SYSTEM) + strcat(buf, "|VV_SYSTEM"); + if (vp->v_iflag & VI_XLOCK) + strcat(buf, "|VI_XLOCK"); + if (vp->v_iflag & VI_XWANT) + strcat(buf, "|VI_XWANT"); + if (vp->v_iflag & VI_BWAIT) + strcat(buf, "|VI_BWAIT"); + if (vp->v_iflag & VI_DOOMED) + strcat(buf, "|VI_DOOMED"); + if (vp->v_iflag & VI_FREE) + strcat(buf, "|VI_FREE"); + if (vp->v_vflag & VV_OBJBUF) + strcat(buf, "|VV_OBJBUF"); + if (buf[0] != '\0') + printf(" flags (%s),", &buf[1]); + lockmgr_printinfo(vp->v_vnlock); + printf("\n"); + if (vp->v_data != NULL) + VOP_PRINT(vp); +} + +#ifdef DDB +#include <ddb/ddb.h> +/* + * List all of the locked vnodes in the system. + * Called when debugging the kernel. + */ +DB_SHOW_COMMAND(lockedvnods, lockedvnodes) +{ + struct mount *mp, *nmp; + struct vnode *vp; + + /* + * Note: because this is DDB, we can't obey the locking semantics + * for these structures, which means we could catch an inconsistent + * state and dereference a nasty pointer. Not much to be done + * about that. + */ + printf("Locked vnodes\n"); + for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) { + nmp = TAILQ_NEXT(mp, mnt_list); + TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { + if (VOP_ISLOCKED(vp, NULL)) + vprint(NULL, vp); + } + nmp = TAILQ_NEXT(mp, mnt_list); + } +} +#endif + +/* + * Fill in a struct xvfsconf based on a struct vfsconf. + */ +static void +vfsconf2x(struct vfsconf *vfsp, struct xvfsconf *xvfsp) +{ + + strcpy(xvfsp->vfc_name, vfsp->vfc_name); + xvfsp->vfc_typenum = vfsp->vfc_typenum; + xvfsp->vfc_refcount = vfsp->vfc_refcount; + xvfsp->vfc_flags = vfsp->vfc_flags; + /* + * These are unused in userland, we keep them + * to not break binary compatibility. + */ + xvfsp->vfc_vfsops = NULL; + xvfsp->vfc_next = NULL; +} + +static int +sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS) +{ + struct vfsconf *vfsp; + struct xvfsconf *xvfsp; + int cnt, error, i; + + cnt = 0; + for (vfsp = vfsconf; vfsp != NULL; vfsp = vfsp->vfc_next) + cnt++; + xvfsp = malloc(sizeof(struct xvfsconf) * cnt, M_TEMP, M_WAITOK); + /* + * Handle the race that we will have here when struct vfsconf + * will be locked down by using both cnt and checking vfc_next + * against NULL to determine the end of the loop. The race will + * happen because we will have to unlock before calling malloc(). + * We are protected by Giant for now. + */ + i = 0; + for (vfsp = vfsconf; vfsp != NULL && i < cnt; vfsp = vfsp->vfc_next) { + vfsconf2x(vfsp, xvfsp + i); + i++; + } + error = SYSCTL_OUT(req, xvfsp, sizeof(struct xvfsconf) * i); + free(xvfsp, M_TEMP); + return (error); +} + +SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLFLAG_RD, NULL, 0, sysctl_vfs_conflist, + "S,xvfsconf", "List of all configured filesystems"); + +/* + * Top level filesystem related information gathering. + */ +static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS); + +static int +vfs_sysctl(SYSCTL_HANDLER_ARGS) +{ + int *name = (int *)arg1 - 1; /* XXX */ + u_int namelen = arg2 + 1; /* XXX */ + struct vfsconf *vfsp; + struct xvfsconf xvfsp; + + printf("WARNING: userland calling deprecated sysctl, " + "please rebuild world\n"); + +#if 1 || defined(COMPAT_PRELITE2) + /* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */ + if (namelen == 1) + return (sysctl_ovfs_conf(oidp, arg1, arg2, req)); +#endif + + switch (name[1]) { + case VFS_MAXTYPENUM: + if (namelen != 2) + return (ENOTDIR); + return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int))); + case VFS_CONF: + if (namelen != 3) + return (ENOTDIR); /* overloaded */ + for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) + if (vfsp->vfc_typenum == name[2]) + break; + if (vfsp == NULL) + return (EOPNOTSUPP); + vfsconf2x(vfsp, &xvfsp); + return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp))); + } + return (EOPNOTSUPP); +} + +SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP, vfs_sysctl, + "Generic filesystem"); + +#if 1 || defined(COMPAT_PRELITE2) + +static int +sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS) +{ + int error; + struct vfsconf *vfsp; + struct ovfsconf ovfs; + + for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) { + ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */ + strcpy(ovfs.vfc_name, vfsp->vfc_name); + ovfs.vfc_index = vfsp->vfc_typenum; + ovfs.vfc_refcount = vfsp->vfc_refcount; + ovfs.vfc_flags = vfsp->vfc_flags; + error = SYSCTL_OUT(req, &ovfs, sizeof ovfs); + if (error) + return error; + } + return 0; +} + +#endif /* 1 || COMPAT_PRELITE2 */ + +#define KINFO_VNODESLOP 10 +#ifdef notyet +/* + * Dump vnode list (via sysctl). + */ +/* ARGSUSED */ +static int +sysctl_vnode(SYSCTL_HANDLER_ARGS) +{ + struct xvnode *xvn; + struct thread *td = req->td; + struct mount *mp; + struct vnode *vp; + int error, len, n; + + /* + * Stale numvnodes access is not fatal here. + */ + req->lock = 0; + len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn; + if (!req->oldptr) + /* Make an estimate */ + return (SYSCTL_OUT(req, 0, len)); + + sysctl_wire_old_buffer(req, 0); + xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK); + n = 0; + mtx_lock(&mountlist_mtx); + TAILQ_FOREACH(mp, &mountlist, mnt_list) { + if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td)) + continue; + mtx_lock(&mntvnode_mtx); + TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) { + if (n == len) + break; + vref(vp); + xvn[n].xv_size = sizeof *xvn; + xvn[n].xv_vnode = vp; +#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field + XV_COPY(usecount); + XV_COPY(writecount); + XV_COPY(holdcnt); + XV_COPY(id); + XV_COPY(mount); + XV_COPY(numoutput); + XV_COPY(type); +#undef XV_COPY + xvn[n].xv_flag = vp->v_vflag; + + switch (vp->v_type) { + case VREG: + case VDIR: + case VLNK: + xvn[n].xv_dev = vp->v_cachedfs; + xvn[n].xv_ino = vp->v_cachedid; + break; + case VBLK: + case VCHR: + if (vp->v_rdev == NULL) { + vrele(vp); + continue; + } + xvn[n].xv_dev = dev2udev(vp->v_rdev); + break; + case VSOCK: + xvn[n].xv_socket = vp->v_socket; + break; + case VFIFO: + xvn[n].xv_fifo = vp->v_fifoinfo; + break; + case VNON: + case VBAD: + default: + /* shouldn't happen? */ + vrele(vp); + continue; + } + vrele(vp); + ++n; + } + mtx_unlock(&mntvnode_mtx); + mtx_lock(&mountlist_mtx); + vfs_unbusy(mp, td); + if (n == len) + break; + } + mtx_unlock(&mountlist_mtx); + + error = SYSCTL_OUT(req, xvn, n * sizeof *xvn); + free(xvn, M_TEMP); + return (error); +} + +SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD, + 0, 0, sysctl_vnode, "S,xvnode", ""); +#endif + +/* + * Check to see if a filesystem is mounted on a block device. + */ +int +vfs_mountedon(vp) + struct vnode *vp; +{ + + if (vp->v_rdev->si_mountpoint != NULL) + return (EBUSY); + return (0); +} + +/* + * Unmount all filesystems. The list is traversed in reverse order + * of mounting to avoid dependencies. + */ +void +vfs_unmountall() +{ + struct mount *mp; + struct thread *td; + int error; + + if (curthread != NULL) + td = curthread; + else + td = FIRST_THREAD_IN_PROC(initproc); /* XXX XXX proc0? */ + /* + * Since this only runs when rebooting, it is not interlocked. + */ + while(!TAILQ_EMPTY(&mountlist)) { + mp = TAILQ_LAST(&mountlist, mntlist); + error = dounmount(mp, MNT_FORCE, td); + if (error) { + TAILQ_REMOVE(&mountlist, mp, mnt_list); + printf("unmount of %s failed (", + mp->mnt_stat.f_mntonname); + if (error == EBUSY) + printf("BUSY)\n"); + else + printf("%d)\n", error); + } else { + /* The unmount has removed mp from the mountlist */ + } + } +} + +/* + * perform msync on all vnodes under a mount point + * the mount point must be locked. + */ +void +vfs_msync(struct mount *mp, int flags) +{ + struct vnode *vp, *nvp; + struct vm_object *obj; + int tries; + + GIANT_REQUIRED; + + tries = 5; + 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); + + VI_LOCK(vp); + if (vp->v_iflag & VI_XLOCK) { /* XXX: what if MNT_WAIT? */ + VI_UNLOCK(vp); + continue; + } + + if ((vp->v_iflag & VI_OBJDIRTY) && + (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) { + mtx_unlock(&mntvnode_mtx); + if (!vget(vp, + LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK, + curthread)) { + if (vp->v_vflag & VV_NOSYNC) { /* unlinked */ + vput(vp); + mtx_lock(&mntvnode_mtx); + continue; + } + + if (VOP_GETVOBJECT(vp, &obj) == 0) { + VM_OBJECT_LOCK(obj); + vm_object_page_clean(obj, 0, 0, + flags == MNT_WAIT ? + OBJPC_SYNC : OBJPC_NOSYNC); + VM_OBJECT_UNLOCK(obj); + } + vput(vp); + } + mtx_lock(&mntvnode_mtx); + if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) { + if (--tries > 0) + goto loop; + break; + } + } else + VI_UNLOCK(vp); + } + 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; + + ASSERT_VI_LOCKED(vp, "vfree"); + s = splbio(); + mtx_lock(&vnode_free_list_mtx); + KASSERT((vp->v_iflag & VI_FREE) == 0, ("vnode already free")); + if (vp->v_iflag & VI_AGE) { + TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); + } else { + TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); + } + freevnodes++; + mtx_unlock(&vnode_free_list_mtx); + vp->v_iflag &= ~VI_AGE; + vp->v_iflag |= VI_FREE; + splx(s); +} + +/* + * Opposite of vfree() - mark a vnode as in use. + */ +void +vbusy(vp) + struct vnode *vp; +{ + int s; + + s = splbio(); + ASSERT_VI_LOCKED(vp, "vbusy"); + KASSERT((vp->v_iflag & VI_FREE) != 0, ("vnode not free")); + + mtx_lock(&vnode_free_list_mtx); + TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); + freevnodes--; + mtx_unlock(&vnode_free_list_mtx); + + vp->v_iflag &= ~(VI_FREE|VI_AGE); + 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; +{ + + if (vp->v_pollinfo == NULL) + v_addpollinfo(vp); + mtx_lock(&vp->v_pollinfo->vpi_lock); + if (vp->v_pollinfo->vpi_revents & events) { + /* + * This leaves events we are not interested + * in available for the other process which + * which presumably had requested them + * (otherwise they would never have been + * recorded). + */ + events &= vp->v_pollinfo->vpi_revents; + vp->v_pollinfo->vpi_revents &= ~events; + + mtx_unlock(&vp->v_pollinfo->vpi_lock); + return events; + } + vp->v_pollinfo->vpi_events |= events; + selrecord(td, &vp->v_pollinfo->vpi_selinfo); + mtx_unlock(&vp->v_pollinfo->vpi_lock); + return 0; +} + +/* + * Note the occurrence of an event. If the VN_POLLEVENT macro is used, + * it is possible for us to miss an event due to race conditions, but + * that condition is expected to be rare, so for the moment it is the + * preferred interface. + */ +void +vn_pollevent(vp, events) + struct vnode *vp; + short events; +{ + + if (vp->v_pollinfo == NULL) + v_addpollinfo(vp); + mtx_lock(&vp->v_pollinfo->vpi_lock); + if (vp->v_pollinfo->vpi_events & events) { + /* + * We clear vpi_events so that we don't + * call selwakeup() twice if two events are + * posted before the polling process(es) is + * awakened. This also ensures that we take at + * most one selwakeup() if the polling process + * is no longer interested. However, it does + * mean that only one event can be noticed at + * a time. (Perhaps we should only clear those + * event bits which we note?) XXX + */ + vp->v_pollinfo->vpi_events = 0; /* &= ~events ??? */ + vp->v_pollinfo->vpi_revents |= events; + selwakeup(&vp->v_pollinfo->vpi_selinfo); + } + mtx_unlock(&vp->v_pollinfo->vpi_lock); +} + +/* + * Wake up anyone polling on vp because it is being revoked. + * This depends on dead_poll() returning POLLHUP for correct + * behavior. + */ +void +vn_pollgone(vp) + struct vnode *vp; +{ + + mtx_lock(&vp->v_pollinfo->vpi_lock); + VN_KNOTE(vp, NOTE_REVOKE); + if (vp->v_pollinfo->vpi_events) { + vp->v_pollinfo->vpi_events = 0; + 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 (*)(struct vop_close_args *))nullop) +static int sync_fsync(struct vop_fsync_args *); +static int sync_inactive(struct vop_inactive_args *); +static int sync_reclaim(struct vop_reclaim_args *); + +static vop_t **sync_vnodeop_p; +static struct vnodeopv_entry_desc sync_vnodeop_entries[] = { + { &vop_default_desc, (vop_t *) vop_eopnotsupp }, + { &vop_close_desc, (vop_t *) sync_close }, /* close */ + { &vop_fsync_desc, (vop_t *) sync_fsync }, /* fsync */ + { &vop_inactive_desc, (vop_t *) sync_inactive }, /* inactive */ + { &vop_reclaim_desc, (vop_t *) sync_reclaim }, /* reclaim */ + { &vop_lock_desc, (vop_t *) vop_stdlock }, /* lock */ + { &vop_unlock_desc, (vop_t *) vop_stdunlock }, /* unlock */ + { &vop_islocked_desc, (vop_t *) vop_stdislocked }, /* islocked */ + { NULL, NULL } +}; +static struct vnodeopv_desc sync_vnodeop_opv_desc = + { &sync_vnodeop_p, sync_vnodeop_entries }; + +VNODEOP_SET(sync_vnodeop_opv_desc); + +/* + * Create a new filesystem syncer vnode for the specified mount point. + */ +int +vfs_allocate_syncvnode(mp) + struct mount *mp; +{ + struct vnode *vp; + static long start, incr, next; + int error; + + /* Allocate a new vnode */ + if ((error = getnewvnode("syncer", mp, sync_vnodeop_p, &vp)) != 0) { + mp->mnt_syncer = NULL; + return (error); + } + vp->v_type = VNON; + /* + * Place the vnode onto the syncer worklist. We attempt to + * scatter them about on the list so that they will go off + * at evenly distributed times even if all the filesystems + * are mounted at once. + */ + next += incr; + if (next == 0 || next > syncer_maxdelay) { + start /= 2; + incr /= 2; + if (start == 0) { + start = syncer_maxdelay / 2; + incr = syncer_maxdelay; + } + next = start; + } + VI_LOCK(vp); + vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0); + VI_UNLOCK(vp); + mp->mnt_syncer = vp; + return (0); +} + +/* + * Do a lazy sync of the filesystem. + */ +static int +sync_fsync(ap) + struct vop_fsync_args /* { + struct vnode *a_vp; + struct ucred *a_cred; + int a_waitfor; + struct thread *a_td; + } */ *ap; +{ + struct vnode *syncvp = ap->a_vp; + struct mount *mp = syncvp->v_mount; + struct thread *td = ap->a_td; + int error, asyncflag; + + /* + * We only need to do something if this is a lazy evaluation. + */ + if (ap->a_waitfor != MNT_LAZY) + return (0); + + /* + * Move ourselves to the back of the sync list. + */ + VI_LOCK(syncvp); + vn_syncer_add_to_worklist(syncvp, syncdelay); + VI_UNLOCK(syncvp); + + /* + * Walk the list of vnodes pushing all that are dirty and + * not already on the sync list. + */ + mtx_lock(&mountlist_mtx); + if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_mtx, td) != 0) { + mtx_unlock(&mountlist_mtx); + return (0); + } + if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) { + vfs_unbusy(mp, td); + return (0); + } + asyncflag = mp->mnt_flag & MNT_ASYNC; + mp->mnt_flag &= ~MNT_ASYNC; + vfs_msync(mp, MNT_NOWAIT); + error = VFS_SYNC(mp, MNT_LAZY, ap->a_cred, td); + if (asyncflag) + mp->mnt_flag |= MNT_ASYNC; + vn_finished_write(mp); + vfs_unbusy(mp, td); + return (error); +} + +/* + * The syncer vnode is no referenced. + */ +static int +sync_inactive(ap) + struct vop_inactive_args /* { + struct vnode *a_vp; + struct thread *a_td; + } */ *ap; +{ + + VOP_UNLOCK(ap->a_vp, 0, ap->a_td); + vgone(ap->a_vp); + return (0); +} + +/* + * The syncer vnode is no longer needed and is being decommissioned. + * + * Modifications to the worklist must be protected 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; + VI_LOCK(vp); + if (vp->v_iflag & VI_ONWORKLST) { + mtx_lock(&sync_mtx); + LIST_REMOVE(vp, v_synclist); + mtx_unlock(&sync_mtx); + vp->v_iflag &= ~VI_ONWORKLST; + } + VI_UNLOCK(vp); + splx(s); + + 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)) { + uma_zfree(namei_zone, ndp->ni_cnd.cn_pnbuf); + ndp->ni_cnd.cn_flags &= ~HASBUF; + } + if (!(flags & NDF_NO_DVP_UNLOCK) && + (ndp->ni_cnd.cn_flags & LOCKPARENT) && + ndp->ni_dvp != ndp->ni_vp) + VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_thread); + if (!(flags & NDF_NO_DVP_RELE) && + (ndp->ni_cnd.cn_flags & (LOCKPARENT|WANTPARENT))) { + vrele(ndp->ni_dvp); + ndp->ni_dvp = NULL; + } + if (!(flags & NDF_NO_VP_UNLOCK) && + (ndp->ni_cnd.cn_flags & LOCKLEAF) && ndp->ni_vp) + VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_thread); + if (!(flags & NDF_NO_VP_RELE) && + ndp->ni_vp) { + vrele(ndp->ni_vp); + ndp->ni_vp = NULL; + } + if (!(flags & NDF_NO_STARTDIR_RELE) && + (ndp->ni_cnd.cn_flags & SAVESTART)) { + vrele(ndp->ni_startdir); + ndp->ni_startdir = NULL; + } +} + +/* + * Common filesystem object access control check routine. Accepts a + * vnode's type, "mode", uid and gid, requested access mode, credentials, + * and optional call-by-reference privused argument allowing vaccess() + * to indicate to the caller whether privilege was used to satisfy the + * request (obsoleted). Returns 0 on success, or an errno on failure. + */ +int +vaccess(type, file_mode, file_uid, file_gid, acc_mode, cred, privused) + enum vtype type; + mode_t file_mode; + uid_t file_uid; + gid_t file_gid; + mode_t acc_mode; + struct ucred *cred; + int *privused; +{ + mode_t dac_granted; +#ifdef CAPABILITIES + mode_t cap_granted; +#endif + + /* + * Look for a normal, non-privileged way to access the file/directory + * as requested. If it exists, go with that. + */ + + if (privused != NULL) + *privused = 0; + + dac_granted = 0; + + /* Check the owner. */ + if (cred->cr_uid == file_uid) { + dac_granted |= VADMIN; + if (file_mode & S_IXUSR) + dac_granted |= VEXEC; + if (file_mode & S_IRUSR) + dac_granted |= VREAD; + if (file_mode & S_IWUSR) + dac_granted |= (VWRITE | VAPPEND); + + if ((acc_mode & dac_granted) == acc_mode) + return (0); + + goto privcheck; + } + + /* Otherwise, check the groups (first match) */ + if (groupmember(file_gid, cred)) { + if (file_mode & S_IXGRP) + dac_granted |= VEXEC; + if (file_mode & S_IRGRP) + dac_granted |= VREAD; + if (file_mode & S_IWGRP) + dac_granted |= (VWRITE | VAPPEND); + + if ((acc_mode & dac_granted) == acc_mode) + return (0); + + goto privcheck; + } + + /* Otherwise, check everyone else. */ + if (file_mode & S_IXOTH) + dac_granted |= VEXEC; + if (file_mode & S_IROTH) + dac_granted |= VREAD; + if (file_mode & S_IWOTH) + dac_granted |= (VWRITE | VAPPEND); + if ((acc_mode & dac_granted) == acc_mode) + return (0); + +privcheck: + if (!suser_cred(cred, PRISON_ROOT)) { + /* XXX audit: privilege used */ + if (privused != NULL) + *privused = 1; + return (0); + } + +#ifdef CAPABILITIES + /* + * Build a capability mask to determine if the set of capabilities + * satisfies the requirements when combined with the granted mask + * from above. + * For each capability, if the capability is required, bitwise + * or the request type onto the cap_granted mask. + */ + cap_granted = 0; + + if (type == VDIR) { + /* + * For directories, use CAP_DAC_READ_SEARCH to satisfy + * VEXEC requests, instead of CAP_DAC_EXECUTE. + */ + if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && + !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) + cap_granted |= VEXEC; + } else { + if ((acc_mode & VEXEC) && ((dac_granted & VEXEC) == 0) && + !cap_check(cred, NULL, CAP_DAC_EXECUTE, PRISON_ROOT)) + cap_granted |= VEXEC; + } + + if ((acc_mode & VREAD) && ((dac_granted & VREAD) == 0) && + !cap_check(cred, NULL, CAP_DAC_READ_SEARCH, PRISON_ROOT)) + cap_granted |= VREAD; + + if ((acc_mode & VWRITE) && ((dac_granted & VWRITE) == 0) && + !cap_check(cred, NULL, CAP_DAC_WRITE, PRISON_ROOT)) + cap_granted |= (VWRITE | VAPPEND); + + if ((acc_mode & VADMIN) && ((dac_granted & VADMIN) == 0) && + !cap_check(cred, NULL, CAP_FOWNER, PRISON_ROOT)) + cap_granted |= VADMIN; + + if ((acc_mode & (cap_granted | dac_granted)) == acc_mode) { + /* XXX audit: privilege used */ + if (privused != NULL) + *privused = 1; + return (0); + } +#endif + + return ((acc_mode & VADMIN) ? EPERM : EACCES); +} + +/* + * Credential check based on process requesting service, and per-attribute + * permissions. + */ +int +extattr_check_cred(struct vnode *vp, int attrnamespace, + struct ucred *cred, struct thread *td, int access) +{ + + /* + * Kernel-invoked always succeeds. + */ + if (cred == NOCRED) + return (0); + + /* + * Do not allow privileged processes in jail to directly + * manipulate system attributes. + * + * XXX What capability should apply here? + * Probably CAP_SYS_SETFFLAG. + */ + switch (attrnamespace) { + case EXTATTR_NAMESPACE_SYSTEM: + /* Potentially should be: return (EPERM); */ + return (suser_cred(cred, 0)); + case EXTATTR_NAMESPACE_USER: + return (VOP_ACCESS(vp, access, cred, td)); + default: + return (EPERM); + } +} |
