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freebsd-skq/sys/kern/vfs_subr.c
markj e06021a945 Launder VPO_NOSYNC pages upon vnode deactivation. 
As of r234483, vnode deactivation causes non-VPO_NOSYNC pages to be
laundered. This behaviour has two problems:

1. Dirty VPO_NOSYNC pages must be laundered before the vnode can be
   reclaimed, and this work may be unfairly deferred to the vnlru process
   or an unrelated application when the system is under vnode pressure.
2. Deactivation of a vnode with dirty VPO_NOSYNC pages requires a scan of
   the corresponding VM object's memq for non-VPO_NOSYNC dirty pages; if
   the laundry thread needs to launder pages from an unreferenced such
   vnode, it will reactivate and deactivate the vnode with each laundering,
   potentially resulting in a large number of expensive scans.

Therefore, ensure that all dirty pages are laundered upon deactivation,
i.e., when all maps of the vnode are removed and all references are
released.

Reviewed by:	alc, kib
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D8641
2016-11-26 21:00:27 +00:00

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/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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_compat.h"
#include "opt_ddb.h"
#include "opt_watchdog.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/condvar.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/event.h>
#include <sys/eventhandler.h>
#include <sys/extattr.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/pctrie.h>
#include <sys/priv.h>
#include <sys/reboot.h>
#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/sleepqueue.h>
#include <sys/smp.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <sys/watchdog.h>
#include <machine/stdarg.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#include <vm/uma.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
static void delmntque(struct vnode *vp);
static int flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo,
int slpflag, int slptimeo);
static void syncer_shutdown(void *arg, int howto);
static int vtryrecycle(struct vnode *vp);
static void v_init_counters(struct vnode *);
static void v_incr_usecount(struct vnode *);
static void v_incr_usecount_locked(struct vnode *);
static void v_incr_devcount(struct vnode *);
static void v_decr_devcount(struct vnode *);
static void vgonel(struct vnode *);
static void vfs_knllock(void *arg);
static void vfs_knlunlock(void *arg);
static void vfs_knl_assert_locked(void *arg);
static void vfs_knl_assert_unlocked(void *arg);
static void vnlru_return_batches(struct vfsops *mnt_op);
static void destroy_vpollinfo(struct vpollinfo *vi);
/*
* Number of vnodes in existence. Increased whenever getnewvnode()
* allocates a new vnode, decreased in vdropl() for VI_DOOMED vnode.
*/
static unsigned long numvnodes;
SYSCTL_ULONG(_vfs, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
"Number of vnodes in existence");
static u_long vnodes_created;
SYSCTL_ULONG(_vfs, OID_AUTO, vnodes_created, CTLFLAG_RD, &vnodes_created,
0, "Number of vnodes created by getnewvnode");
static u_long mnt_free_list_batch = 128;
SYSCTL_ULONG(_vfs, OID_AUTO, mnt_free_list_batch, CTLFLAG_RW,
&mnt_free_list_batch, 0, "Limit of vnodes held on mnt's free list");
/*
* Conversion tables for conversion from vnode types to inode formats
* and back.
*/
enum vtype iftovt_tab[16] = {
VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
};
int vttoif_tab[10] = {
0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
S_IFSOCK, S_IFIFO, S_IFMT, S_IFMT
};
/*
* List of vnodes that are ready for recycling.
*/
static TAILQ_HEAD(freelst, vnode) vnode_free_list;
/*
* "Free" vnode target. Free vnodes are rarely completely free, but are
* just ones that are cheap to recycle. Usually they are for files which
* have been stat'd but not read; these usually have inode and namecache
* data attached to them. This target is the preferred minimum size of a
* sub-cache consisting mostly of such files. The system balances the size
* of this sub-cache with its complement to try to prevent either from
* thrashing while the other is relatively inactive. The targets express
* a preference for the best balance.
*
* "Above" this target there are 2 further targets (watermarks) related
* to recyling of free vnodes. In the best-operating case, the cache is
* exactly full, the free list has size between vlowat and vhiwat above the
* free target, and recycling from it and normal use maintains this state.
* Sometimes the free list is below vlowat or even empty, but this state
* is even better for immediate use provided the cache is not full.
* Otherwise, vnlru_proc() runs to reclaim enough vnodes (usually non-free
* ones) to reach one of these states. The watermarks are currently hard-
* coded as 4% and 9% of the available space higher. These and the default
* of 25% for wantfreevnodes are too large if the memory size is large.
* E.g., 9% of 75% of MAXVNODES is more than 566000 vnodes to reclaim
* whenever vnlru_proc() becomes active.
*/
static u_long wantfreevnodes;
SYSCTL_ULONG(_vfs, OID_AUTO, wantfreevnodes, CTLFLAG_RW,
&wantfreevnodes, 0, "Target for minimum number of \"free\" vnodes");
static u_long freevnodes;
SYSCTL_ULONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD,
&freevnodes, 0, "Number of \"free\" vnodes");
static u_long recycles_count;
SYSCTL_ULONG(_vfs, OID_AUTO, recycles, CTLFLAG_RD, &recycles_count, 0,
"Number of vnodes recycled to meet vnode cache targets");
/*
* Various variables used for debugging the new implementation of
* reassignbuf().
* XXX these are probably of (very) limited utility now.
*/
static int reassignbufcalls;
SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0,
"Number of calls to reassignbuf");
static u_long free_owe_inact;
SYSCTL_ULONG(_vfs, OID_AUTO, free_owe_inact, CTLFLAG_RD, &free_owe_inact, 0,
"Number of times free vnodes kept on active list due to VFS "
"owing inactivation");
/* To keep more than one thread at a time from running vfs_getnewfsid */
static struct mtx mntid_mtx;
/*
* Lock for any access to the following:
* vnode_free_list
* numvnodes
* freevnodes
*/
static struct mtx vnode_free_list_mtx;
/* Publicly exported FS */
struct nfs_public nfs_pub;
static uma_zone_t buf_trie_zone;
/* Zone for allocation of new vnodes - used exclusively by getnewvnode() */
static uma_zone_t vnode_zone;
static uma_zone_t vnodepoll_zone;
/*
* The workitem queue.
*
* It is useful to delay writes of file data and filesystem metadata
* for tens of seconds so that quickly created and deleted files need
* not waste disk bandwidth being created and removed. To realize this,
* we append vnodes to a "workitem" queue. When running with a soft
* updates implementation, most pending metadata dependencies should
* not wait for more than a few seconds. Thus, mounted on block devices
* are delayed only about a half the time that file data is delayed.
* Similarly, directory updates are more critical, so are only delayed
* about a third the time that file data is delayed. Thus, there are
* SYNCER_MAXDELAY queues that are processed round-robin at a rate of
* one each second (driven off the filesystem syncer process). The
* syncer_delayno variable indicates the next queue that is to be processed.
* Items that need to be processed soon are placed in this queue:
*
* syncer_workitem_pending[syncer_delayno]
*
* A delay of fifteen seconds is done by placing the request fifteen
* entries later in the queue:
*
* syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
*
*/
static int syncer_delayno;
static long syncer_mask;
LIST_HEAD(synclist, bufobj);
static struct synclist *syncer_workitem_pending;
/*
* The sync_mtx protects:
* bo->bo_synclist
* sync_vnode_count
* syncer_delayno
* syncer_state
* syncer_workitem_pending
* syncer_worklist_len
* rushjob
*/
static struct mtx sync_mtx;
static struct cv sync_wakeup;
#define SYNCER_MAXDELAY 32
static int syncer_maxdelay = SYNCER_MAXDELAY; /* maximum delay time */
static int syncdelay = 30; /* max time to delay syncing data */
static int filedelay = 30; /* time to delay syncing files */
SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
"Time to delay syncing files (in seconds)");
static int dirdelay = 29; /* time to delay syncing directories */
SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
"Time to delay syncing directories (in seconds)");
static int metadelay = 28; /* time to delay syncing metadata */
SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
"Time to delay syncing metadata (in seconds)");
static int rushjob; /* number of slots to run ASAP */
static int stat_rush_requests; /* number of times I/O speeded up */
SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0,
"Number of times I/O speeded up (rush requests)");
/*
* When shutting down the syncer, run it at four times normal speed.
*/
#define SYNCER_SHUTDOWN_SPEEDUP 4
static int sync_vnode_count;
static int syncer_worklist_len;
static enum { SYNCER_RUNNING, SYNCER_SHUTTING_DOWN, SYNCER_FINAL_DELAY }
syncer_state;
/* Target for maximum number of vnodes. */
int desiredvnodes;
static int gapvnodes; /* gap between wanted and desired */
static int vhiwat; /* enough extras after expansion */
static int vlowat; /* minimal extras before expansion */
static int vstir; /* nonzero to stir non-free vnodes */
static volatile int vsmalltrigger = 8; /* pref to keep if > this many pages */
static int
sysctl_update_desiredvnodes(SYSCTL_HANDLER_ARGS)
{
int error, old_desiredvnodes;
old_desiredvnodes = desiredvnodes;
if ((error = sysctl_handle_int(oidp, arg1, arg2, req)) != 0)
return (error);
if (old_desiredvnodes != desiredvnodes) {
wantfreevnodes = desiredvnodes / 4;
/* XXX locking seems to be incomplete. */
vfs_hash_changesize(desiredvnodes);
cache_changesize(desiredvnodes);
}
return (0);
}
SYSCTL_PROC(_kern, KERN_MAXVNODES, maxvnodes,
CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, &desiredvnodes, 0,
sysctl_update_desiredvnodes, "I", "Target for maximum number of vnodes");
SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
&wantfreevnodes, 0, "Old name for vfs.wantfreevnodes (legacy)");
static int vnlru_nowhere;
SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
&vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
/* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
static int vnsz2log;
/*
* Support for the bufobj clean & dirty pctrie.
*/
static void *
buf_trie_alloc(struct pctrie *ptree)
{
return uma_zalloc(buf_trie_zone, M_NOWAIT);
}
static void
buf_trie_free(struct pctrie *ptree, void *node)
{
uma_zfree(buf_trie_zone, node);
}
PCTRIE_DEFINE(BUF, buf, b_lblkno, buf_trie_alloc, buf_trie_free);
/*
* Initialize the vnode management data structures.
*
* Reevaluate the following cap on the number of vnodes after the physical
* memory size exceeds 512GB. In the limit, as the physical memory size
* grows, the ratio of the memory size in KB to to vnodes approaches 64:1.
*/
#ifndef MAXVNODES_MAX
#define MAXVNODES_MAX (512 * 1024 * 1024 / 64) /* 8M */
#endif
/*
* Initialize a vnode as it first enters the zone.
*/
static int
vnode_init(void *mem, int size, int flags)
{
struct vnode *vp;
struct bufobj *bo;
vp = mem;
bzero(vp, size);
/*
* Setup locks.
*/
vp->v_vnlock = &vp->v_lock;
mtx_init(&vp->v_interlock, "vnode interlock", NULL, MTX_DEF);
/*
* By default, don't allow shared locks unless filesystems opt-in.
*/
lockinit(vp->v_vnlock, PVFS, "vnode", VLKTIMEOUT,
LK_NOSHARE | LK_IS_VNODE);
/*
* Initialize bufobj.
*/
bo = &vp->v_bufobj;
rw_init(BO_LOCKPTR(bo), "bufobj interlock");
bo->bo_private = vp;
TAILQ_INIT(&bo->bo_clean.bv_hd);
TAILQ_INIT(&bo->bo_dirty.bv_hd);
/*
* Initialize namecache.
*/
LIST_INIT(&vp->v_cache_src);
TAILQ_INIT(&vp->v_cache_dst);
/*
* Initialize rangelocks.
*/
rangelock_init(&vp->v_rl);
return (0);
}
/*
* Free a vnode when it is cleared from the zone.
*/
static void
vnode_fini(void *mem, int size)
{
struct vnode *vp;
struct bufobj *bo;
vp = mem;
rangelock_destroy(&vp->v_rl);
lockdestroy(vp->v_vnlock);
mtx_destroy(&vp->v_interlock);
bo = &vp->v_bufobj;
rw_destroy(BO_LOCKPTR(bo));
}
/*
* Provide the size of NFS nclnode and NFS fh for calculation of the
* vnode memory consumption. The size is specified directly to
* eliminate dependency on NFS-private header.
*
* Other filesystems may use bigger or smaller (like UFS and ZFS)
* private inode data, but the NFS-based estimation is ample enough.
* Still, we care about differences in the size between 64- and 32-bit
* platforms.
*
* Namecache structure size is heuristically
* sizeof(struct namecache_ts) + CACHE_PATH_CUTOFF + 1.
*/
#ifdef _LP64
#define NFS_NCLNODE_SZ (528 + 64)
#define NC_SZ 148
#else
#define NFS_NCLNODE_SZ (360 + 32)
#define NC_SZ 92
#endif
static void
vntblinit(void *dummy __unused)
{
u_int i;
int physvnodes, virtvnodes;
/*
* Desiredvnodes is a function of the physical memory size and the
* kernel's heap size. Generally speaking, it scales with the
* physical memory size. The ratio of desiredvnodes to the physical
* memory size is 1:16 until desiredvnodes exceeds 98,304.
* Thereafter, the
* marginal ratio of desiredvnodes to the physical memory size is
* 1:64. However, desiredvnodes is limited by the kernel's heap
* size. The memory required by desiredvnodes vnodes and vm objects
* must not exceed 1/10th of the kernel's heap size.
*/
physvnodes = maxproc + pgtok(vm_cnt.v_page_count) / 64 +
3 * min(98304 * 16, pgtok(vm_cnt.v_page_count)) / 64;
virtvnodes = vm_kmem_size / (10 * (sizeof(struct vm_object) +
sizeof(struct vnode) + NC_SZ * ncsizefactor + NFS_NCLNODE_SZ));
desiredvnodes = min(physvnodes, virtvnodes);
if (desiredvnodes > MAXVNODES_MAX) {
if (bootverbose)
printf("Reducing kern.maxvnodes %d -> %d\n",
desiredvnodes, MAXVNODES_MAX);
desiredvnodes = MAXVNODES_MAX;
}
wantfreevnodes = desiredvnodes / 4;
mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
TAILQ_INIT(&vnode_free_list);
mtx_init(&vnode_free_list_mtx, "vnode_free_list", NULL, MTX_DEF);
vnode_zone = uma_zcreate("VNODE", sizeof (struct vnode), NULL, NULL,
vnode_init, vnode_fini, UMA_ALIGN_PTR, 0);
vnodepoll_zone = uma_zcreate("VNODEPOLL", sizeof (struct vpollinfo),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
/*
* Preallocate enough nodes to support one-per buf so that
* we can not fail an insert. reassignbuf() callers can not
* tolerate the insertion failure.
*/
buf_trie_zone = uma_zcreate("BUF TRIE", pctrie_node_size(),
NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR,
UMA_ZONE_NOFREE | UMA_ZONE_VM);
uma_prealloc(buf_trie_zone, nbuf);
/*
* Initialize the filesystem syncer.
*/
syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
&syncer_mask);
syncer_maxdelay = syncer_mask + 1;
mtx_init(&sync_mtx, "Syncer mtx", NULL, MTX_DEF);
cv_init(&sync_wakeup, "syncer");
for (i = 1; i <= sizeof(struct vnode); i <<= 1)
vnsz2log++;
vnsz2log--;
}
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vntblinit, NULL);
/*
* Mark a mount point as busy. Used to synchronize access and to delay
* unmounting. Eventually, mountlist_mtx is not released on failure.
*
* vfs_busy() is a custom lock, it can block the caller.
* vfs_busy() only sleeps if the unmount is active on the mount point.
* For a mountpoint mp, vfs_busy-enforced lock is before lock of any
* vnode belonging to mp.
*
* Lookup uses vfs_busy() to traverse mount points.
* root fs var fs
* / vnode lock A / vnode lock (/var) D
* /var vnode lock B /log vnode lock(/var/log) E
* vfs_busy lock C vfs_busy lock F
*
* Within each file system, the lock order is C->A->B and F->D->E.
*
* When traversing across mounts, the system follows that lock order:
*
* C->A->B
* |
* +->F->D->E
*
* The lookup() process for namei("/var") illustrates the process:
* VOP_LOOKUP() obtains B while A is held
* vfs_busy() obtains a shared lock on F while A and B are held
* vput() releases lock on B
* vput() releases lock on A
* VFS_ROOT() obtains lock on D while shared lock on F is held
* vfs_unbusy() releases shared lock on F
* vn_lock() obtains lock on deadfs vnode vp_crossmp instead of A.
* Attempt to lock A (instead of vp_crossmp) while D is held would
* violate the global order, causing deadlocks.
*
* dounmount() locks B while F is drained.
*/
int
vfs_busy(struct mount *mp, int flags)
{
MPASS((flags & ~MBF_MASK) == 0);
CTR3(KTR_VFS, "%s: mp %p with flags %d", __func__, mp, flags);
MNT_ILOCK(mp);
MNT_REF(mp);
/*
* If mount point is currently being unmounted, sleep until the
* mount point fate is decided. If thread doing the unmounting fails,
* it will clear MNTK_UNMOUNT flag before waking us up, indicating
* that this mount point has survived the unmount attempt and vfs_busy
* should retry. Otherwise the unmounter thread will set MNTK_REFEXPIRE
* flag in addition to MNTK_UNMOUNT, indicating that mount point is
* about to be really destroyed. vfs_busy needs to release its
* reference on the mount point in this case and return with ENOENT,
* telling the caller that mount mount it tried to busy is no longer
* valid.
*/
while (mp->mnt_kern_flag & MNTK_UNMOUNT) {
if (flags & MBF_NOWAIT || mp->mnt_kern_flag & MNTK_REFEXPIRE) {
MNT_REL(mp);
MNT_IUNLOCK(mp);
CTR1(KTR_VFS, "%s: failed busying before sleeping",
__func__);
return (ENOENT);
}
if (flags & MBF_MNTLSTLOCK)
mtx_unlock(&mountlist_mtx);
mp->mnt_kern_flag |= MNTK_MWAIT;
msleep(mp, MNT_MTX(mp), PVFS | PDROP, "vfs_busy", 0);
if (flags & MBF_MNTLSTLOCK)
mtx_lock(&mountlist_mtx);
MNT_ILOCK(mp);
}
if (flags & MBF_MNTLSTLOCK)
mtx_unlock(&mountlist_mtx);
mp->mnt_lockref++;
MNT_IUNLOCK(mp);
return (0);
}
/*
* Free a busy filesystem.
*/
void
vfs_unbusy(struct mount *mp)
{
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
MNT_ILOCK(mp);
MNT_REL(mp);
KASSERT(mp->mnt_lockref > 0, ("negative mnt_lockref"));
mp->mnt_lockref--;
if (mp->mnt_lockref == 0 && (mp->mnt_kern_flag & MNTK_DRAINING) != 0) {
MPASS(mp->mnt_kern_flag & MNTK_UNMOUNT);
CTR1(KTR_VFS, "%s: waking up waiters", __func__);
mp->mnt_kern_flag &= ~MNTK_DRAINING;
wakeup(&mp->mnt_lockref);
}
MNT_IUNLOCK(mp);
}
/*
* Lookup a mount point by filesystem identifier.
*/
struct mount *
vfs_getvfs(fsid_t *fsid)
{
struct mount *mp;
CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
vfs_ref(mp);
mtx_unlock(&mountlist_mtx);
return (mp);
}
}
mtx_unlock(&mountlist_mtx);
CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
return ((struct mount *) 0);
}
/*
* Lookup a mount point by filesystem identifier, busying it before
* returning.
*
* To avoid congestion on mountlist_mtx, implement simple direct-mapped
* cache for popular filesystem identifiers. The cache is lockess, using
* the fact that struct mount's are never freed. In worst case we may
* get pointer to unmounted or even different filesystem, so we have to
* check what we got, and go slow way if so.
*/
struct mount *
vfs_busyfs(fsid_t *fsid)
{
#define FSID_CACHE_SIZE 256
typedef struct mount * volatile vmp_t;
static vmp_t cache[FSID_CACHE_SIZE];
struct mount *mp;
int error;
uint32_t hash;
CTR2(KTR_VFS, "%s: fsid %p", __func__, fsid);
hash = fsid->val[0] ^ fsid->val[1];
hash = (hash >> 16 ^ hash) & (FSID_CACHE_SIZE - 1);
mp = cache[hash];
if (mp == NULL ||
mp->mnt_stat.f_fsid.val[0] != fsid->val[0] ||
mp->mnt_stat.f_fsid.val[1] != fsid->val[1])
goto slow;
if (vfs_busy(mp, 0) != 0) {
cache[hash] = NULL;
goto slow;
}
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1])
return (mp);
else
vfs_unbusy(mp);
slow:
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
error = vfs_busy(mp, MBF_MNTLSTLOCK);
if (error) {
cache[hash] = NULL;
mtx_unlock(&mountlist_mtx);
return (NULL);
}
cache[hash] = mp;
return (mp);
}
}
CTR2(KTR_VFS, "%s: lookup failed for %p id", __func__, fsid);
mtx_unlock(&mountlist_mtx);
return ((struct mount *) 0);
}
/*
* Check if a user can access privileged mount options.
*/
int
vfs_suser(struct mount *mp, struct thread *td)
{
int error;
/*
* If the thread is jailed, but this is not a jail-friendly file
* system, deny immediately.
*/
if (!(mp->mnt_vfc->vfc_flags & VFCF_JAIL) && jailed(td->td_ucred))
return (EPERM);
/*
* If the file system was mounted outside the jail of the calling
* thread, deny immediately.
*/
if (prison_check(td->td_ucred, mp->mnt_cred) != 0)
return (EPERM);
/*
* If file system supports delegated administration, we don't check
* for the PRIV_VFS_MOUNT_OWNER privilege - it will be better verified
* by the file system itself.
* If this is not the user that did original mount, we check for
* the PRIV_VFS_MOUNT_OWNER privilege.
*/
if (!(mp->mnt_vfc->vfc_flags & VFCF_DELEGADMIN) &&
mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
if ((error = priv_check(td, PRIV_VFS_MOUNT_OWNER)) != 0)
return (error);
}
return (0);
}
/*
* Get a new unique fsid. Try to make its val[0] unique, since this value
* will be used to create fake device numbers for stat(). Also try (but
* not so hard) make its val[0] unique mod 2^16, since some emulators only
* support 16-bit device numbers. We end up with unique val[0]'s for the
* first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
*
* Keep in mind that several mounts may be running in parallel. Starting
* the search one past where the previous search terminated is both a
* micro-optimization and a defense against returning the same fsid to
* different mounts.
*/
void
vfs_getnewfsid(struct mount *mp)
{
static uint16_t mntid_base;
struct mount *nmp;
fsid_t tfsid;
int mtype;
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
mtx_lock(&mntid_mtx);
mtype = mp->mnt_vfc->vfc_typenum;
tfsid.val[1] = mtype;
mtype = (mtype & 0xFF) << 24;
for (;;) {
tfsid.val[0] = makedev(255,
mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
mntid_base++;
if ((nmp = vfs_getvfs(&tfsid)) == NULL)
break;
vfs_rel(nmp);
}
mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
mtx_unlock(&mntid_mtx);
}
/*
* Knob to control the precision of file timestamps:
*
* 0 = seconds only; nanoseconds zeroed.
* 1 = seconds and nanoseconds, accurate within 1/HZ.
* 2 = seconds and nanoseconds, truncated to microseconds.
* >=3 = seconds and nanoseconds, maximum precision.
*/
enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
static int timestamp_precision = TSP_USEC;
SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
&timestamp_precision, 0, "File timestamp precision (0: seconds, "
"1: sec + ns accurate to 1/HZ, 2: sec + ns truncated to ms, "
"3+: sec + ns (max. precision))");
/*
* Get a current timestamp.
*/
void
vfs_timestamp(struct timespec *tsp)
{
struct timeval tv;
switch (timestamp_precision) {
case TSP_SEC:
tsp->tv_sec = time_second;
tsp->tv_nsec = 0;
break;
case TSP_HZ:
getnanotime(tsp);
break;
case TSP_USEC:
microtime(&tv);
TIMEVAL_TO_TIMESPEC(&tv, tsp);
break;
case TSP_NSEC:
default:
nanotime(tsp);
break;
}
}
/*
* Set vnode attributes to VNOVAL
*/
void
vattr_null(struct vattr *vap)
{
vap->va_type = VNON;
vap->va_size = VNOVAL;
vap->va_bytes = VNOVAL;
vap->va_mode = VNOVAL;
vap->va_nlink = VNOVAL;
vap->va_uid = VNOVAL;
vap->va_gid = VNOVAL;
vap->va_fsid = VNOVAL;
vap->va_fileid = VNOVAL;
vap->va_blocksize = VNOVAL;
vap->va_rdev = VNOVAL;
vap->va_atime.tv_sec = VNOVAL;
vap->va_atime.tv_nsec = VNOVAL;
vap->va_mtime.tv_sec = VNOVAL;
vap->va_mtime.tv_nsec = VNOVAL;
vap->va_ctime.tv_sec = VNOVAL;
vap->va_ctime.tv_nsec = VNOVAL;
vap->va_birthtime.tv_sec = VNOVAL;
vap->va_birthtime.tv_nsec = VNOVAL;
vap->va_flags = VNOVAL;
vap->va_gen = VNOVAL;
vap->va_vaflags = 0;
}
/*
* This routine is called when we have too many vnodes. It attempts
* to free <count> vnodes and will potentially free vnodes that still
* have VM backing store (VM backing store is typically the cause
* of a vnode blowout so we want to do this). Therefore, this operation
* is not considered cheap.
*
* A number of conditions may prevent a vnode from being reclaimed.
* the buffer cache may have references on the vnode, a directory
* vnode may still have references due to the namei cache representing
* underlying files, or the vnode may be in active use. It is not
* desirable to reuse such vnodes. These conditions may cause the
* number of vnodes to reach some minimum value regardless of what
* you set kern.maxvnodes to. Do not set kern.maxvnodes too low.
*/
static int
vlrureclaim(struct mount *mp, int reclaim_nc_src, int trigger)
{
struct vnode *vp;
int count, done, target;
done = 0;
vn_start_write(NULL, &mp, V_WAIT);
MNT_ILOCK(mp);
count = mp->mnt_nvnodelistsize;
target = count * (int64_t)gapvnodes / imax(desiredvnodes, 1);
target = target / 10 + 1;
while (count != 0 && done < target) {
vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
while (vp != NULL && vp->v_type == VMARKER)
vp = TAILQ_NEXT(vp, v_nmntvnodes);
if (vp == NULL)
break;
/*
* XXX LRU is completely broken for non-free vnodes. First
* by calling here in mountpoint order, then by moving
* unselected vnodes to the end here, and most grossly by
* removing the vlruvp() function that was supposed to
* maintain the order. (This function was born broken
* since syncer problems prevented it doing anything.) The
* order is closer to LRC (C = Created).
*
* LRU reclaiming of vnodes seems to have last worked in
* FreeBSD-3 where LRU wasn't mentioned under any spelling.
* Then there was no hold count, and inactive vnodes were
* simply put on the free list in LRU order. The separate
* lists also break LRU. We prefer to reclaim from the
* free list for technical reasons. This tends to thrash
* the free list to keep very unrecently used held vnodes.
* The problem is mitigated by keeping the free list large.
*/
TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
--count;
if (!VI_TRYLOCK(vp))
goto next_iter;
/*
* If it's been deconstructed already, it's still
* referenced, or it exceeds the trigger, skip it.
* Also skip free vnodes. We are trying to make space
* to expand the free list, not reduce it.
*/
if (vp->v_usecount ||
(!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
((vp->v_iflag & VI_FREE) != 0) ||
(vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
vp->v_object->resident_page_count > trigger)) {
VI_UNLOCK(vp);
goto next_iter;
}
MNT_IUNLOCK(mp);
vholdl(vp);
if (VOP_LOCK(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_NOWAIT)) {
vdrop(vp);
goto next_iter_mntunlocked;
}
VI_LOCK(vp);
/*
* v_usecount may have been bumped after VOP_LOCK() dropped
* the vnode interlock and before it was locked again.
*
* It is not necessary to recheck VI_DOOMED because it can
* only be set by another thread that holds both the vnode
* lock and vnode interlock. If another thread has the
* vnode lock before we get to VOP_LOCK() and obtains the
* vnode interlock after VOP_LOCK() drops the vnode
* interlock, the other thread will be unable to drop the
* vnode lock before our VOP_LOCK() call fails.
*/
if (vp->v_usecount ||
(!reclaim_nc_src && !LIST_EMPTY(&vp->v_cache_src)) ||
(vp->v_iflag & VI_FREE) != 0 ||
(vp->v_object != NULL &&
vp->v_object->resident_page_count > trigger)) {
VOP_UNLOCK(vp, LK_INTERLOCK);
vdrop(vp);
goto next_iter_mntunlocked;
}
KASSERT((vp->v_iflag & VI_DOOMED) == 0,
("VI_DOOMED unexpectedly detected in vlrureclaim()"));
atomic_add_long(&recycles_count, 1);
vgonel(vp);
VOP_UNLOCK(vp, 0);
vdropl(vp);
done++;
next_iter_mntunlocked:
if (!should_yield())
goto relock_mnt;
goto yield;
next_iter:
if (!should_yield())
continue;
MNT_IUNLOCK(mp);
yield:
kern_yield(PRI_USER);
relock_mnt:
MNT_ILOCK(mp);
}
MNT_IUNLOCK(mp);
vn_finished_write(mp);
return done;
}
static int max_vnlru_free = 10000; /* limit on vnode free requests per call */
SYSCTL_INT(_debug, OID_AUTO, max_vnlru_free, CTLFLAG_RW, &max_vnlru_free,
0,
"limit on vnode free requests per call to the vnlru_free routine");
/*
* Attempt to reduce the free list by the requested amount.
*/
static void
vnlru_free_locked(int count, struct vfsops *mnt_op)
{
struct vnode *vp;
struct mount *mp;
bool tried_batches;
tried_batches = false;
mtx_assert(&vnode_free_list_mtx, MA_OWNED);
if (count > max_vnlru_free)
count = max_vnlru_free;
for (; count > 0; count--) {
vp = TAILQ_FIRST(&vnode_free_list);
/*
* The list can be modified while the free_list_mtx
* has been dropped and vp could be NULL here.
*/
if (vp == NULL) {
if (tried_batches)
break;
mtx_unlock(&vnode_free_list_mtx);
vnlru_return_batches(mnt_op);
tried_batches = true;
mtx_lock(&vnode_free_list_mtx);
continue;
}
VNASSERT(vp->v_op != NULL, vp,
("vnlru_free: vnode already reclaimed."));
KASSERT((vp->v_iflag & VI_FREE) != 0,
("Removing vnode not on freelist"));
KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
("Mangling active vnode"));
TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
/*
* Don't recycle if our vnode is from different type
* of mount point. Note that mp is type-safe, the
* check does not reach unmapped address even if
* vnode is reclaimed.
* Don't recycle if we can't get the interlock without
* blocking.
*/
if ((mnt_op != NULL && (mp = vp->v_mount) != NULL &&
mp->mnt_op != mnt_op) || !VI_TRYLOCK(vp)) {
TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_actfreelist);
continue;
}
VNASSERT((vp->v_iflag & VI_FREE) != 0 && vp->v_holdcnt == 0,
vp, ("vp inconsistent on freelist"));
/*
* The clear of VI_FREE prevents activation of the
* vnode. There is no sense in putting the vnode on
* the mount point active list, only to remove it
* later during recycling. Inline the relevant part
* of vholdl(), to avoid triggering assertions or
* activating.
*/
freevnodes--;
vp->v_iflag &= ~VI_FREE;
refcount_acquire(&vp->v_holdcnt);
mtx_unlock(&vnode_free_list_mtx);
VI_UNLOCK(vp);
vtryrecycle(vp);
/*
* If the recycled succeeded this vdrop will actually free
* the vnode. If not it will simply place it back on
* the free list.
*/
vdrop(vp);
mtx_lock(&vnode_free_list_mtx);
}
}
void
vnlru_free(int count, struct vfsops *mnt_op)
{
mtx_lock(&vnode_free_list_mtx);
vnlru_free_locked(count, mnt_op);
mtx_unlock(&vnode_free_list_mtx);
}
/* XXX some names and initialization are bad for limits and watermarks. */
static int
vspace(void)
{
int space;
gapvnodes = imax(desiredvnodes - wantfreevnodes, 100);
vhiwat = gapvnodes / 11; /* 9% -- just under the 10% in vlrureclaim() */
vlowat = vhiwat / 2;
if (numvnodes > desiredvnodes)
return (0);
space = desiredvnodes - numvnodes;
if (freevnodes > wantfreevnodes)
space += freevnodes - wantfreevnodes;
return (space);
}
static void
vnlru_return_batch_locked(struct mount *mp)
{
struct vnode *vp;
mtx_assert(&mp->mnt_listmtx, MA_OWNED);
if (mp->mnt_tmpfreevnodelistsize == 0)
return;
TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) {
VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp,
("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist"));
vp->v_mflag &= ~VMP_TMPMNTFREELIST;
}
mtx_lock(&vnode_free_list_mtx);
TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist);
freevnodes += mp->mnt_tmpfreevnodelistsize;
mtx_unlock(&vnode_free_list_mtx);
mp->mnt_tmpfreevnodelistsize = 0;
}
static void
vnlru_return_batch(struct mount *mp)
{
mtx_lock(&mp->mnt_listmtx);
vnlru_return_batch_locked(mp);
mtx_unlock(&mp->mnt_listmtx);
}
static void
vnlru_return_batches(struct vfsops *mnt_op)
{
struct mount *mp, *nmp;
bool need_unbusy;
mtx_lock(&mountlist_mtx);
for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
need_unbusy = false;
if (mnt_op != NULL && mp->mnt_op != mnt_op)
goto next;
if (mp->mnt_tmpfreevnodelistsize == 0)
goto next;
if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) == 0) {
vnlru_return_batch(mp);
need_unbusy = true;
mtx_lock(&mountlist_mtx);
}
next:
nmp = TAILQ_NEXT(mp, mnt_list);
if (need_unbusy)
vfs_unbusy(mp);
}
mtx_unlock(&mountlist_mtx);
}
/*
* Attempt to recycle vnodes in a context that is always safe to block.
* Calling vlrurecycle() from the bowels of filesystem code has some
* interesting deadlock problems.
*/
static struct proc *vnlruproc;
static int vnlruproc_sig;
static void
vnlru_proc(void)
{
struct mount *mp, *nmp;
unsigned long ofreevnodes, onumvnodes;
int done, force, reclaim_nc_src, trigger, usevnodes;
EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, vnlruproc,
SHUTDOWN_PRI_FIRST);
force = 0;
for (;;) {
kproc_suspend_check(vnlruproc);
mtx_lock(&vnode_free_list_mtx);
/*
* If numvnodes is too large (due to desiredvnodes being
* adjusted using its sysctl, or emergency growth), first
* try to reduce it by discarding from the free list.
*/
if (numvnodes > desiredvnodes)
vnlru_free_locked(numvnodes - desiredvnodes, NULL);
/*
* Sleep if the vnode cache is in a good state. This is
* when it is not over-full and has space for about a 4%
* or 9% expansion (by growing its size or inexcessively
* reducing its free list). Otherwise, try to reclaim
* space for a 10% expansion.
*/
if (vstir && force == 0) {
force = 1;
vstir = 0;
}
if (vspace() >= vlowat && force == 0) {
vnlruproc_sig = 0;
wakeup(&vnlruproc_sig);
msleep(vnlruproc, &vnode_free_list_mtx,
PVFS|PDROP, "vlruwt", hz);
continue;
}
mtx_unlock(&vnode_free_list_mtx);
done = 0;
ofreevnodes = freevnodes;
onumvnodes = numvnodes;
/*
* Calculate parameters for recycling. These are the same
* throughout the loop to give some semblance of fairness.
* The trigger point is to avoid recycling vnodes with lots
* of resident pages. We aren't trying to free memory; we
* are trying to recycle or at least free vnodes.
*/
if (numvnodes <= desiredvnodes)
usevnodes = numvnodes - freevnodes;
else
usevnodes = numvnodes;
if (usevnodes <= 0)
usevnodes = 1;
/*
* The trigger value is is chosen to give a conservatively
* large value to ensure that it alone doesn't prevent
* making progress. The value can easily be so large that
* it is effectively infinite in some congested and
* misconfigured cases, and this is necessary. Normally
* it is about 8 to 100 (pages), which is quite large.
*/
trigger = vm_cnt.v_page_count * 2 / usevnodes;
if (force < 2)
trigger = vsmalltrigger;
reclaim_nc_src = force >= 3;
mtx_lock(&mountlist_mtx);
for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
nmp = TAILQ_NEXT(mp, mnt_list);
continue;
}
done += vlrureclaim(mp, reclaim_nc_src, trigger);
mtx_lock(&mountlist_mtx);
nmp = TAILQ_NEXT(mp, mnt_list);
vfs_unbusy(mp);
}
mtx_unlock(&mountlist_mtx);
if (onumvnodes > desiredvnodes && numvnodes <= desiredvnodes)
uma_reclaim();
if (done == 0) {
if (force == 0 || force == 1) {
force = 2;
continue;
}
if (force == 2) {
force = 3;
continue;
}
force = 0;
vnlru_nowhere++;
tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
} else
kern_yield(PRI_USER);
/*
* After becoming active to expand above low water, keep
* active until above high water.
*/
force = vspace() < vhiwat;
}
}
static struct kproc_desc vnlru_kp = {
"vnlru",
vnlru_proc,
&vnlruproc
};
SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start,
&vnlru_kp);
/*
* Routines having to do with the management of the vnode table.
*/
/*
* Try to recycle a freed vnode. We abort if anyone picks up a reference
* before we actually vgone(). This function must be called with the vnode
* held to prevent the vnode from being returned to the free list midway
* through vgone().
*/
static int
vtryrecycle(struct vnode *vp)
{
struct mount *vnmp;
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
VNASSERT(vp->v_holdcnt, vp,
("vtryrecycle: Recycling vp %p without a reference.", vp));
/*
* This vnode may found and locked via some other list, if so we
* can't recycle it yet.
*/
if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
CTR2(KTR_VFS,
"%s: impossible to recycle, vp %p lock is already held",
__func__, vp);
return (EWOULDBLOCK);
}
/*
* Don't recycle if its filesystem is being suspended.
*/
if (vn_start_write(vp, &vnmp, V_NOWAIT) != 0) {
VOP_UNLOCK(vp, 0);
CTR2(KTR_VFS,
"%s: impossible to recycle, cannot start the write for %p",
__func__, vp);
return (EBUSY);
}
/*
* If we got this far, we need to acquire the interlock and see if
* anyone picked up this vnode from another list. If not, we will
* mark it with DOOMED via vgonel() so that anyone who does find it
* will skip over it.
*/
VI_LOCK(vp);
if (vp->v_usecount) {
VOP_UNLOCK(vp, LK_INTERLOCK);
vn_finished_write(vnmp);
CTR2(KTR_VFS,
"%s: impossible to recycle, %p is already referenced",
__func__, vp);
return (EBUSY);
}
if ((vp->v_iflag & VI_DOOMED) == 0) {
atomic_add_long(&recycles_count, 1);
vgonel(vp);
}
VOP_UNLOCK(vp, LK_INTERLOCK);
vn_finished_write(vnmp);
return (0);
}
static void
vcheckspace(void)
{
if (vspace() < vlowat && vnlruproc_sig == 0) {
vnlruproc_sig = 1;
wakeup(vnlruproc);
}
}
/*
* Wait if necessary for space for a new vnode.
*/
static int
getnewvnode_wait(int suspended)
{
mtx_assert(&vnode_free_list_mtx, MA_OWNED);
if (numvnodes >= desiredvnodes) {
if (suspended) {
/*
* The file system is being suspended. We cannot
* risk a deadlock here, so allow allocation of
* another vnode even if this would give too many.
*/
return (0);
}
if (vnlruproc_sig == 0) {
vnlruproc_sig = 1; /* avoid unnecessary wakeups */
wakeup(vnlruproc);
}
msleep(&vnlruproc_sig, &vnode_free_list_mtx, PVFS,
"vlruwk", hz);
}
/* Post-adjust like the pre-adjust in getnewvnode(). */
if (numvnodes + 1 > desiredvnodes && freevnodes > 1)
vnlru_free_locked(1, NULL);
return (numvnodes >= desiredvnodes ? ENFILE : 0);
}
/*
* This hack is fragile, and probably not needed any more now that the
* watermark handling works.
*/
void
getnewvnode_reserve(u_int count)
{
struct thread *td;
/* Pre-adjust like the pre-adjust in getnewvnode(), with any count. */
/* XXX no longer so quick, but this part is not racy. */
mtx_lock(&vnode_free_list_mtx);
if (numvnodes + count > desiredvnodes && freevnodes > wantfreevnodes)
vnlru_free_locked(ulmin(numvnodes + count - desiredvnodes,
freevnodes - wantfreevnodes), NULL);
mtx_unlock(&vnode_free_list_mtx);
td = curthread;
/* First try to be quick and racy. */
if (atomic_fetchadd_long(&numvnodes, count) + count <= desiredvnodes) {
td->td_vp_reserv += count;
vcheckspace(); /* XXX no longer so quick, but more racy */
return;
} else
atomic_subtract_long(&numvnodes, count);
mtx_lock(&vnode_free_list_mtx);
while (count > 0) {
if (getnewvnode_wait(0) == 0) {
count--;
td->td_vp_reserv++;
atomic_add_long(&numvnodes, 1);
}
}
vcheckspace();
mtx_unlock(&vnode_free_list_mtx);
}
/*
* This hack is fragile, especially if desiredvnodes or wantvnodes are
* misconfgured or changed significantly. Reducing desiredvnodes below
* the reserved amount should cause bizarre behaviour like reducing it
* below the number of active vnodes -- the system will try to reduce
* numvnodes to match, but should fail, so the subtraction below should
* not overflow.
*/
void
getnewvnode_drop_reserve(void)
{
struct thread *td;
td = curthread;
atomic_subtract_long(&numvnodes, td->td_vp_reserv);
td->td_vp_reserv = 0;
}
/*
* Return the next vnode from the free list.
*/
int
getnewvnode(const char *tag, struct mount *mp, struct vop_vector *vops,
struct vnode **vpp)
{
struct vnode *vp;
struct thread *td;
struct lock_object *lo;
static int cyclecount;
int error;
CTR3(KTR_VFS, "%s: mp %p with tag %s", __func__, mp, tag);
vp = NULL;
td = curthread;
if (td->td_vp_reserv > 0) {
td->td_vp_reserv -= 1;
goto alloc;
}
mtx_lock(&vnode_free_list_mtx);
if (numvnodes < desiredvnodes)
cyclecount = 0;
else if (cyclecount++ >= freevnodes) {
cyclecount = 0;
vstir = 1;
}
/*
* Grow the vnode cache if it will not be above its target max
* after growing. Otherwise, if the free list is nonempty, try
* to reclaim 1 item from it before growing the cache (possibly
* above its target max if the reclamation failed or is delayed).
* Otherwise, wait for some space. In all cases, schedule
* vnlru_proc() if we are getting short of space. The watermarks
* should be chosen so that we never wait or even reclaim from
* the free list to below its target minimum.
*/
if (numvnodes + 1 <= desiredvnodes)
;
else if (freevnodes > 0)
vnlru_free_locked(1, NULL);
else {
error = getnewvnode_wait(mp != NULL && (mp->mnt_kern_flag &
MNTK_SUSPEND));
#if 0 /* XXX Not all VFS_VGET/ffs_vget callers check returns. */
if (error != 0) {
mtx_unlock(&vnode_free_list_mtx);
return (error);
}
#endif
}
vcheckspace();
atomic_add_long(&numvnodes, 1);
mtx_unlock(&vnode_free_list_mtx);
alloc:
atomic_add_long(&vnodes_created, 1);
vp = (struct vnode *) uma_zalloc(vnode_zone, M_WAITOK);
/*
* Locks are given the generic name "vnode" when created.
* Follow the historic practice of using the filesystem
* name when they allocated, e.g., "zfs", "ufs", "nfs, etc.
*
* Locks live in a witness group keyed on their name. Thus,
* when a lock is renamed, it must also move from the witness
* group of its old name to the witness group of its new name.
*
* The change only needs to be made when the vnode moves
* from one filesystem type to another. We ensure that each
* filesystem use a single static name pointer for its tag so
* that we can compare pointers rather than doing a strcmp().
*/
lo = &vp->v_vnlock->lock_object;
if (lo->lo_name != tag) {
lo->lo_name = tag;
WITNESS_DESTROY(lo);
WITNESS_INIT(lo, tag);
}
/*
* By default, don't allow shared locks unless filesystems opt-in.
*/
vp->v_vnlock->lock_object.lo_flags |= LK_NOSHARE;
/*
* Finalize various vnode identity bits.
*/
KASSERT(vp->v_object == NULL, ("stale v_object %p", vp));
KASSERT(vp->v_lockf == NULL, ("stale v_lockf %p", vp));
KASSERT(vp->v_pollinfo == NULL, ("stale v_pollinfo %p", vp));
vp->v_type = VNON;
vp->v_tag = tag;
vp->v_op = vops;
v_init_counters(vp);
vp->v_bufobj.bo_ops = &buf_ops_bio;
#ifdef MAC
mac_vnode_init(vp);
if (mp != NULL && (mp->mnt_flag & MNT_MULTILABEL) == 0)
mac_vnode_associate_singlelabel(mp, vp);
else if (mp == NULL && vops != &dead_vnodeops)
printf("NULL mp in getnewvnode()\n");
#endif
if (mp != NULL) {
vp->v_bufobj.bo_bsize = mp->mnt_stat.f_iosize;
if ((mp->mnt_kern_flag & MNTK_NOKNOTE) != 0)
vp->v_vflag |= VV_NOKNOTE;
}
/*
* For the filesystems which do not use vfs_hash_insert(),
* still initialize v_hash to have vfs_hash_index() useful.
* E.g., nullfs uses vfs_hash_index() on the lower vnode for
* its own hashing.
*/
vp->v_hash = (uintptr_t)vp >> vnsz2log;
*vpp = vp;
return (0);
}
/*
* Delete from old mount point vnode list, if on one.
*/
static void
delmntque(struct vnode *vp)
{
struct mount *mp;
int active;
mp = vp->v_mount;
if (mp == NULL)
return;
MNT_ILOCK(mp);
VI_LOCK(vp);
KASSERT(mp->mnt_activevnodelistsize <= mp->mnt_nvnodelistsize,
("Active vnode list size %d > Vnode list size %d",
mp->mnt_activevnodelistsize, mp->mnt_nvnodelistsize));
active = vp->v_iflag & VI_ACTIVE;
vp->v_iflag &= ~VI_ACTIVE;
if (active) {
mtx_lock(&mp->mnt_listmtx);
TAILQ_REMOVE(&mp->mnt_activevnodelist, vp, v_actfreelist);
mp->mnt_activevnodelistsize--;
mtx_unlock(&mp->mnt_listmtx);
}
vp->v_mount = NULL;
VI_UNLOCK(vp);
VNASSERT(mp->mnt_nvnodelistsize > 0, vp,
("bad mount point vnode list size"));
TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
mp->mnt_nvnodelistsize--;
MNT_REL(mp);
MNT_IUNLOCK(mp);
}
static void
insmntque_stddtr(struct vnode *vp, void *dtr_arg)
{
vp->v_data = NULL;
vp->v_op = &dead_vnodeops;
vgone(vp);
vput(vp);
}
/*
* Insert into list of vnodes for the new mount point, if available.
*/
int
insmntque1(struct vnode *vp, struct mount *mp,
void (*dtr)(struct vnode *, void *), void *dtr_arg)
{
KASSERT(vp->v_mount == NULL,
("insmntque: vnode already on per mount vnode list"));
VNASSERT(mp != NULL, vp, ("Don't call insmntque(foo, NULL)"));
ASSERT_VOP_ELOCKED(vp, "insmntque: non-locked vp");
/*
* We acquire the vnode interlock early to ensure that the
* vnode cannot be recycled by another process releasing a
* holdcnt on it before we get it on both the vnode list
* and the active vnode list. The mount mutex protects only
* manipulation of the vnode list and the vnode freelist
* mutex protects only manipulation of the active vnode list.
* Hence the need to hold the vnode interlock throughout.
*/
MNT_ILOCK(mp);
VI_LOCK(vp);
if (((mp->mnt_kern_flag & MNTK_NOINSMNTQ) != 0 &&
((mp->mnt_kern_flag & MNTK_UNMOUNTF) != 0 ||
mp->mnt_nvnodelistsize == 0)) &&
(vp->v_vflag & VV_FORCEINSMQ) == 0) {
VI_UNLOCK(vp);
MNT_IUNLOCK(mp);
if (dtr != NULL)
dtr(vp, dtr_arg);
return (EBUSY);
}
vp->v_mount = mp;
MNT_REF(mp);
TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
VNASSERT(mp->mnt_nvnodelistsize >= 0, vp,
("neg mount point vnode list size"));
mp->mnt_nvnodelistsize++;
KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
("Activating already active vnode"));
vp->v_iflag |= VI_ACTIVE;
mtx_lock(&mp->mnt_listmtx);
TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
mp->mnt_activevnodelistsize++;
mtx_unlock(&mp->mnt_listmtx);
VI_UNLOCK(vp);
MNT_IUNLOCK(mp);
return (0);
}
int
insmntque(struct vnode *vp, struct mount *mp)
{
return (insmntque1(vp, mp, insmntque_stddtr, NULL));
}
/*
* Flush out and invalidate all buffers associated with a bufobj
* Called with the underlying object locked.
*/
int
bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
{
int error;
BO_LOCK(bo);
if (flags & V_SAVE) {
error = bufobj_wwait(bo, slpflag, slptimeo);
if (error) {
BO_UNLOCK(bo);
return (error);
}
if (bo->bo_dirty.bv_cnt > 0) {
BO_UNLOCK(bo);
if ((error = BO_SYNC(bo, MNT_WAIT)) != 0)
return (error);
/*
* XXX We could save a lock/unlock if this was only
* enabled under INVARIANTS
*/
BO_LOCK(bo);
if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
panic("vinvalbuf: dirty bufs");
}
}
/*
* If you alter this loop please notice that interlock is dropped and
* reacquired in flushbuflist. Special care is needed to ensure that
* no race conditions occur from this.
*/
do {
error = flushbuflist(&bo->bo_clean,
flags, bo, slpflag, slptimeo);
if (error == 0 && !(flags & V_CLEANONLY))
error = flushbuflist(&bo->bo_dirty,
flags, bo, slpflag, slptimeo);
if (error != 0 && error != EAGAIN) {
BO_UNLOCK(bo);
return (error);
}
} while (error != 0);
/*
* Wait for I/O to complete. XXX needs cleaning up. The vnode can
* have write I/O in-progress but if there is a VM object then the
* VM object can also have read-I/O in-progress.
*/
do {
bufobj_wwait(bo, 0, 0);
BO_UNLOCK(bo);
if (bo->bo_object != NULL) {
VM_OBJECT_WLOCK(bo->bo_object);
vm_object_pip_wait(bo->bo_object, "bovlbx");
VM_OBJECT_WUNLOCK(bo->bo_object);
}
BO_LOCK(bo);
} while (bo->bo_numoutput > 0);
BO_UNLOCK(bo);
/*
* Destroy the copy in the VM cache, too.
*/
if (bo->bo_object != NULL &&
(flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
VM_OBJECT_WLOCK(bo->bo_object);
vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
OBJPR_CLEANONLY : 0);
VM_OBJECT_WUNLOCK(bo->bo_object);
}
#ifdef INVARIANTS
BO_LOCK(bo);
if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
(bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
panic("vinvalbuf: flush failed");
BO_UNLOCK(bo);
#endif
return (0);
}
/*
* Flush out and invalidate all buffers associated with a vnode.
* Called with the underlying object locked.
*/
int
vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
{
CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
ASSERT_VOP_LOCKED(vp, "vinvalbuf");
if (vp->v_object != NULL && vp->v_object->handle != vp)
return (0);
return (bufobj_invalbuf(&vp->v_bufobj, flags, slpflag, slptimeo));
}
/*
* Flush out buffers on the specified list.
*
*/
static int
flushbuflist(struct bufv *bufv, int flags, struct bufobj *bo, int slpflag,
int slptimeo)
{
struct buf *bp, *nbp;
int retval, error;
daddr_t lblkno;
b_xflags_t xflags;
ASSERT_BO_WLOCKED(bo);
retval = 0;
TAILQ_FOREACH_SAFE(bp, &bufv->bv_hd, b_bobufs, nbp) {
if (((flags & V_NORMAL) && (bp->b_xflags & BX_ALTDATA)) ||
((flags & V_ALT) && (bp->b_xflags & BX_ALTDATA) == 0)) {
continue;
}
lblkno = 0;
xflags = 0;
if (nbp != NULL) {
lblkno = nbp->b_lblkno;
xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
}
retval = EAGAIN;
error = BUF_TIMELOCK(bp,
LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK, BO_LOCKPTR(bo),
"flushbuf", slpflag, slptimeo);
if (error) {
BO_LOCK(bo);
return (error != ENOLCK ? error : EAGAIN);
}
KASSERT(bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p",
bp, bp->b_bufobj, bo));
/*
* XXX Since there are no node locks for NFS, I
* believe there is a slight chance that a delayed
* write will occur while sleeping just above, so
* check for it.
*/
if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
(flags & V_SAVE)) {
bremfree(bp);
bp->b_flags |= B_ASYNC;
bwrite(bp);
BO_LOCK(bo);
return (EAGAIN); /* XXX: why not loop ? */
}
bremfree(bp);
bp->b_flags |= (B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
BO_LOCK(bo);
nbp = gbincore(bo, lblkno);
if (nbp == NULL || (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
!= xflags)
break; /* nbp invalid */
}
return (retval);
}
int
bnoreuselist(struct bufv *bufv, struct bufobj *bo, daddr_t startn, daddr_t endn)
{
struct buf *bp;
int error;
daddr_t lblkno;
ASSERT_BO_LOCKED(bo);
for (lblkno = startn;;) {
again:
bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
if (bp == NULL || bp->b_lblkno >= endn ||
bp->b_lblkno < startn)
break;
error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);
if (error != 0) {
BO_RLOCK(bo);
if (error == ENOLCK)
goto again;
return (error);
}
KASSERT(bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p",
bp, bp->b_bufobj, bo));
lblkno = bp->b_lblkno + 1;
if ((bp->b_flags & B_MANAGED) == 0)
bremfree(bp);
bp->b_flags |= B_RELBUF;
/*
* In the VMIO case, use the B_NOREUSE flag to hint that the
* pages backing each buffer in the range are unlikely to be
* reused. Dirty buffers will have the hint applied once
* they've been written.
*/
if (bp->b_vp->v_object != NULL)
bp->b_flags |= B_NOREUSE;
brelse(bp);
BO_RLOCK(bo);
}
return (0);
}
/*
* Truncate a file's buffer and pages to a specified length. This
* is in lieu of the old vinvalbuf mechanism, which performed unneeded
* sync activity.
*/
int
vtruncbuf(struct vnode *vp, struct ucred *cred, off_t length, int blksize)
{
struct buf *bp, *nbp;
int anyfreed;
int trunclbn;
struct bufobj *bo;
CTR5(KTR_VFS, "%s: vp %p with cred %p and block %d:%ju", __func__,
vp, cred, blksize, (uintmax_t)length);
/*
* Round up to the *next* lbn.
*/
trunclbn = howmany(length, blksize);
ASSERT_VOP_LOCKED(vp, "vtruncbuf");
restart:
bo = &vp->v_bufobj;
BO_LOCK(bo);
anyfreed = 1;
for (;anyfreed;) {
anyfreed = 0;
TAILQ_FOREACH_SAFE(bp, &bo->bo_clean.bv_hd, b_bobufs, nbp) {
if (bp->b_lblkno < trunclbn)
continue;
if (BUF_LOCK(bp,
LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
BO_LOCKPTR(bo)) == ENOLCK)
goto restart;
bremfree(bp);
bp->b_flags |= (B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
BO_LOCK(bo);
if (nbp != NULL &&
(((nbp->b_xflags & BX_VNCLEAN) == 0) ||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI))) {
BO_UNLOCK(bo);
goto restart;
}
}
TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
if (bp->b_lblkno < trunclbn)
continue;
if (BUF_LOCK(bp,
LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
BO_LOCKPTR(bo)) == ENOLCK)
goto restart;
bremfree(bp);
bp->b_flags |= (B_INVAL | B_RELBUF);
bp->b_flags &= ~B_ASYNC;
brelse(bp);
anyfreed = 1;
BO_LOCK(bo);
if (nbp != NULL &&
(((nbp->b_xflags & BX_VNDIRTY) == 0) ||
(nbp->b_vp != vp) ||
(nbp->b_flags & B_DELWRI) == 0)) {
BO_UNLOCK(bo);
goto restart;
}
}
}
if (length > 0) {
restartsync:
TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
if (bp->b_lblkno > 0)
continue;
/*
* Since we hold the vnode lock this should only
* fail if we're racing with the buf daemon.
*/
if (BUF_LOCK(bp,
LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
BO_LOCKPTR(bo)) == ENOLCK) {
goto restart;
}
VNASSERT((bp->b_flags & B_DELWRI), vp,
("buf(%p) on dirty queue without DELWRI", bp));
bremfree(bp);
bawrite(bp);
BO_LOCK(bo);
goto restartsync;
}
}
bufobj_wwait(bo, 0, 0);
BO_UNLOCK(bo);
vnode_pager_setsize(vp, length);
return (0);
}
static void
buf_vlist_remove(struct buf *bp)
{
struct bufv *bv;
KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp));
ASSERT_BO_WLOCKED(bp->b_bufobj);
KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) !=
(BX_VNDIRTY|BX_VNCLEAN),
("buf_vlist_remove: Buf %p is on two lists", bp));
if (bp->b_xflags & BX_VNDIRTY)
bv = &bp->b_bufobj->bo_dirty;
else
bv = &bp->b_bufobj->bo_clean;
BUF_PCTRIE_REMOVE(&bv->bv_root, bp->b_lblkno);
TAILQ_REMOVE(&bv->bv_hd, bp, b_bobufs);
bv->bv_cnt--;
bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
}
/*
* Add the buffer to the sorted clean or dirty block list.
*
* NOTE: xflags is passed as a constant, optimizing this inline function!
*/
static void
buf_vlist_add(struct buf *bp, struct bufobj *bo, b_xflags_t xflags)
{
struct bufv *bv;
struct buf *n;
int error;
ASSERT_BO_WLOCKED(bo);
KASSERT((xflags & BX_VNDIRTY) == 0 || (bo->bo_flag & BO_DEAD) == 0,
("dead bo %p", bo));
KASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0,
("buf_vlist_add: Buf %p has existing xflags %d", bp, bp->b_xflags));
bp->b_xflags |= xflags;
if (xflags & BX_VNDIRTY)
bv = &bo->bo_dirty;
else
bv = &bo->bo_clean;
/*
* Keep the list ordered. Optimize empty list insertion. Assume
* we tend to grow at the tail so lookup_le should usually be cheaper
* than _ge.
*/
if (bv->bv_cnt == 0 ||
bp->b_lblkno > TAILQ_LAST(&bv->bv_hd, buflists)->b_lblkno)
TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
else if ((n = BUF_PCTRIE_LOOKUP_LE(&bv->bv_root, bp->b_lblkno)) == NULL)
TAILQ_INSERT_HEAD(&bv->bv_hd, bp, b_bobufs);
else
TAILQ_INSERT_AFTER(&bv->bv_hd, n, bp, b_bobufs);
error = BUF_PCTRIE_INSERT(&bv->bv_root, bp);
if (error)
panic("buf_vlist_add: Preallocated nodes insufficient.");
bv->bv_cnt++;
}
/*
* Look up a buffer using the buffer tries.
*/
struct buf *
gbincore(struct bufobj *bo, daddr_t lblkno)
{
struct buf *bp;
ASSERT_BO_LOCKED(bo);
bp = BUF_PCTRIE_LOOKUP(&bo->bo_clean.bv_root, lblkno);
if (bp != NULL)
return (bp);
return BUF_PCTRIE_LOOKUP(&bo->bo_dirty.bv_root, lblkno);
}
/*
* Associate a buffer with a vnode.
*/
void
bgetvp(struct vnode *vp, struct buf *bp)
{
struct bufobj *bo;
bo = &vp->v_bufobj;
ASSERT_BO_WLOCKED(bo);
VNASSERT(bp->b_vp == NULL, bp->b_vp, ("bgetvp: not free"));
CTR3(KTR_BUF, "bgetvp(%p) vp %p flags %X", bp, vp, bp->b_flags);
VNASSERT((bp->b_xflags & (BX_VNDIRTY|BX_VNCLEAN)) == 0, vp,
("bgetvp: bp already attached! %p", bp));
vhold(vp);
bp->b_vp = vp;
bp->b_bufobj = bo;
/*
* Insert onto list for new vnode.
*/
buf_vlist_add(bp, bo, BX_VNCLEAN);
}
/*
* Disassociate a buffer from a vnode.
*/
void
brelvp(struct buf *bp)
{
struct bufobj *bo;
struct vnode *vp;
CTR3(KTR_BUF, "brelvp(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
/*
* Delete from old vnode list, if on one.
*/
vp = bp->b_vp; /* XXX */
bo = bp->b_bufobj;
BO_LOCK(bo);
if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
buf_vlist_remove(bp);
else
panic("brelvp: Buffer %p not on queue.", bp);
if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
bo->bo_flag &= ~BO_ONWORKLST;
mtx_lock(&sync_mtx);
LIST_REMOVE(bo, bo_synclist);
syncer_worklist_len--;
mtx_unlock(&sync_mtx);
}
bp->b_vp = NULL;
bp->b_bufobj = NULL;
BO_UNLOCK(bo);
vdrop(vp);
}
/*
* Add an item to the syncer work queue.
*/
static void
vn_syncer_add_to_worklist(struct bufobj *bo, int delay)
{
int slot;
ASSERT_BO_WLOCKED(bo);
mtx_lock(&sync_mtx);
if (bo->bo_flag & BO_ONWORKLST)
LIST_REMOVE(bo, bo_synclist);
else {
bo->bo_flag |= BO_ONWORKLST;
syncer_worklist_len++;
}
if (delay > syncer_maxdelay - 2)
delay = syncer_maxdelay - 2;
slot = (syncer_delayno + delay) & syncer_mask;
LIST_INSERT_HEAD(&syncer_workitem_pending[slot], bo, bo_synclist);
mtx_unlock(&sync_mtx);
}
static int
sysctl_vfs_worklist_len(SYSCTL_HANDLER_ARGS)
{
int error, len;
mtx_lock(&sync_mtx);
len = syncer_worklist_len - sync_vnode_count;
mtx_unlock(&sync_mtx);
error = SYSCTL_OUT(req, &len, sizeof(len));
return (error);
}
SYSCTL_PROC(_vfs, OID_AUTO, worklist_len, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
sysctl_vfs_worklist_len, "I", "Syncer thread worklist length");
static struct proc *updateproc;
static void sched_sync(void);
static struct kproc_desc up_kp = {
"syncer",
sched_sync,
&updateproc
};
SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp);
static int
sync_vnode(struct synclist *slp, struct bufobj **bo, struct thread *td)
{
struct vnode *vp;
struct mount *mp;
*bo = LIST_FIRST(slp);
if (*bo == NULL)
return (0);
vp = bo2vnode(*bo);
if (VOP_ISLOCKED(vp) != 0 || VI_TRYLOCK(vp) == 0)
return (1);
/*
* We use vhold in case the vnode does not
* successfully sync. vhold prevents the vnode from
* going away when we unlock the sync_mtx so that
* we can acquire the vnode interlock.
*/
vholdl(vp);
mtx_unlock(&sync_mtx);
VI_UNLOCK(vp);
if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
vdrop(vp);
mtx_lock(&sync_mtx);
return (*bo == LIST_FIRST(slp));
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
(void) VOP_FSYNC(vp, MNT_LAZY, td);
VOP_UNLOCK(vp, 0);
vn_finished_write(mp);
BO_LOCK(*bo);
if (((*bo)->bo_flag & BO_ONWORKLST) != 0) {
/*
* Put us back on the worklist. The worklist
* routine will remove us from our current
* position and then add us back in at a later
* position.
*/
vn_syncer_add_to_worklist(*bo, syncdelay);
}
BO_UNLOCK(*bo);
vdrop(vp);
mtx_lock(&sync_mtx);
return (0);
}
static int first_printf = 1;
/*
* System filesystem synchronizer daemon.
*/
static void
sched_sync(void)
{
struct synclist *next, *slp;
struct bufobj *bo;
long starttime;
struct thread *td = curthread;
int last_work_seen;
int net_worklist_len;
int syncer_final_iter;
int error;
last_work_seen = 0;
syncer_final_iter = 0;
syncer_state = SYNCER_RUNNING;
starttime = time_uptime;
td->td_pflags |= TDP_NORUNNINGBUF;
EVENTHANDLER_REGISTER(shutdown_pre_sync, syncer_shutdown, td->td_proc,
SHUTDOWN_PRI_LAST);
mtx_lock(&sync_mtx);
for (;;) {
if (syncer_state == SYNCER_FINAL_DELAY &&
syncer_final_iter == 0) {
mtx_unlock(&sync_mtx);
kproc_suspend_check(td->td_proc);
mtx_lock(&sync_mtx);
}
net_worklist_len = syncer_worklist_len - sync_vnode_count;
if (syncer_state != SYNCER_RUNNING &&
starttime != time_uptime) {
if (first_printf) {
printf("\nSyncing disks, vnodes remaining... ");
first_printf = 0;
}
printf("%d ", net_worklist_len);
}
starttime = time_uptime;
/*
* Push files whose dirty time has expired. Be careful
* of interrupt race on slp queue.
*
* Skip over empty worklist slots when shutting down.
*/
do {
slp = &syncer_workitem_pending[syncer_delayno];
syncer_delayno += 1;
if (syncer_delayno == syncer_maxdelay)
syncer_delayno = 0;
next = &syncer_workitem_pending[syncer_delayno];
/*
* If the worklist has wrapped since the
* it was emptied of all but syncer vnodes,
* switch to the FINAL_DELAY state and run
* for one more second.
*/
if (syncer_state == SYNCER_SHUTTING_DOWN &&
net_worklist_len == 0 &&
last_work_seen == syncer_delayno) {
syncer_state = SYNCER_FINAL_DELAY;
syncer_final_iter = SYNCER_SHUTDOWN_SPEEDUP;
}
} while (syncer_state != SYNCER_RUNNING && LIST_EMPTY(slp) &&
syncer_worklist_len > 0);
/*
* Keep track of the last time there was anything
* on the worklist other than syncer vnodes.
* Return to the SHUTTING_DOWN state if any
* new work appears.
*/
if (net_worklist_len > 0 || syncer_state == SYNCER_RUNNING)
last_work_seen = syncer_delayno;
if (net_worklist_len > 0 && syncer_state == SYNCER_FINAL_DELAY)
syncer_state = SYNCER_SHUTTING_DOWN;
while (!LIST_EMPTY(slp)) {
error = sync_vnode(slp, &bo, td);
if (error == 1) {
LIST_REMOVE(bo, bo_synclist);
LIST_INSERT_HEAD(next, bo, bo_synclist);
continue;
}
if (first_printf == 0) {
/*
* Drop the sync mutex, because some watchdog
* drivers need to sleep while patting
*/
mtx_unlock(&sync_mtx);
wdog_kern_pat(WD_LASTVAL);
mtx_lock(&sync_mtx);
}
}
if (syncer_state == SYNCER_FINAL_DELAY && syncer_final_iter > 0)
syncer_final_iter--;
/*
* The variable rushjob allows the kernel to speed up the
* processing of the filesystem syncer process. A rushjob
* value of N tells the filesystem syncer to process the next
* N seconds worth of work on its queue ASAP. Currently rushjob
* is used by the soft update code to speed up the filesystem
* syncer process when the incore state is getting so far
* ahead of the disk that the kernel memory pool is being
* threatened with exhaustion.
*/
if (rushjob > 0) {
rushjob -= 1;
continue;
}
/*
* Just sleep for a short period of time between
* iterations when shutting down to allow some I/O
* to happen.
*
* If it has taken us less than a second to process the
* current work, then wait. Otherwise start right over
* again. We can still lose time if any single round
* takes more than two seconds, but it does not really
* matter as we are just trying to generally pace the
* filesystem activity.
*/
if (syncer_state != SYNCER_RUNNING ||
time_uptime == starttime) {
thread_lock(td);
sched_prio(td, PPAUSE);
thread_unlock(td);
}
if (syncer_state != SYNCER_RUNNING)
cv_timedwait(&sync_wakeup, &sync_mtx,
hz / SYNCER_SHUTDOWN_SPEEDUP);
else if (time_uptime == starttime)
cv_timedwait(&sync_wakeup, &sync_mtx, hz);
}
}
/*
* Request the syncer daemon to speed up its work.
* We never push it to speed up more than half of its
* normal turn time, otherwise it could take over the cpu.
*/
int
speedup_syncer(void)
{
int ret = 0;
mtx_lock(&sync_mtx);
if (rushjob < syncdelay / 2) {
rushjob += 1;
stat_rush_requests += 1;
ret = 1;
}
mtx_unlock(&sync_mtx);
cv_broadcast(&sync_wakeup);
return (ret);
}
/*
* Tell the syncer to speed up its work and run though its work
* list several times, then tell it to shut down.
*/
static void
syncer_shutdown(void *arg, int howto)
{
if (howto & RB_NOSYNC)
return;
mtx_lock(&sync_mtx);
syncer_state = SYNCER_SHUTTING_DOWN;
rushjob = 0;
mtx_unlock(&sync_mtx);
cv_broadcast(&sync_wakeup);
kproc_shutdown(arg, howto);
}
void
syncer_suspend(void)
{
syncer_shutdown(updateproc, 0);
}
void
syncer_resume(void)
{
mtx_lock(&sync_mtx);
first_printf = 1;
syncer_state = SYNCER_RUNNING;
mtx_unlock(&sync_mtx);
cv_broadcast(&sync_wakeup);
kproc_resume(updateproc);
}
/*
* Reassign a buffer from one vnode to another.
* Used to assign file specific control information
* (indirect blocks) to the vnode to which they belong.
*/
void
reassignbuf(struct buf *bp)
{
struct vnode *vp;
struct bufobj *bo;
int delay;
#ifdef INVARIANTS
struct bufv *bv;
#endif
vp = bp->b_vp;
bo = bp->b_bufobj;
++reassignbufcalls;
CTR3(KTR_BUF, "reassignbuf(%p) vp %p flags %X",
bp, bp->b_vp, bp->b_flags);
/*
* B_PAGING flagged buffers cannot be reassigned because their vp
* is not fully linked in.
*/
if (bp->b_flags & B_PAGING)
panic("cannot reassign paging buffer");
/*
* Delete from old vnode list, if on one.
*/
BO_LOCK(bo);
if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN))
buf_vlist_remove(bp);
else
panic("reassignbuf: Buffer %p not on queue.", bp);
/*
* If dirty, put on list of dirty buffers; otherwise insert onto list
* of clean buffers.
*/
if (bp->b_flags & B_DELWRI) {
if ((bo->bo_flag & BO_ONWORKLST) == 0) {
switch (vp->v_type) {
case VDIR:
delay = dirdelay;
break;
case VCHR:
delay = metadelay;
break;
default:
delay = filedelay;
}
vn_syncer_add_to_worklist(bo, delay);
}
buf_vlist_add(bp, bo, BX_VNDIRTY);
} else {
buf_vlist_add(bp, bo, BX_VNCLEAN);
if ((bo->bo_flag & BO_ONWORKLST) && bo->bo_dirty.bv_cnt == 0) {
mtx_lock(&sync_mtx);
LIST_REMOVE(bo, bo_synclist);
syncer_worklist_len--;
mtx_unlock(&sync_mtx);
bo->bo_flag &= ~BO_ONWORKLST;
}
}
#ifdef INVARIANTS
bv = &bo->bo_clean;
bp = TAILQ_FIRST(&bv->bv_hd);
KASSERT(bp == NULL || bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
bp = TAILQ_LAST(&bv->bv_hd, buflists);
KASSERT(bp == NULL || bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
bv = &bo->bo_dirty;
bp = TAILQ_FIRST(&bv->bv_hd);
KASSERT(bp == NULL || bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
bp = TAILQ_LAST(&bv->bv_hd, buflists);
KASSERT(bp == NULL || bp->b_bufobj == bo,
("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo));
#endif
BO_UNLOCK(bo);
}
/*
* A temporary hack until refcount_* APIs are sorted out.
*/
static __inline int
vfs_refcount_acquire_if_not_zero(volatile u_int *count)
{
u_int old;
for (;;) {
old = *count;
if (old == 0)
return (0);
if (atomic_cmpset_int(count, old, old + 1))
return (1);
}
}
static __inline int
vfs_refcount_release_if_not_last(volatile u_int *count)
{
u_int old;
for (;;) {
old = *count;
if (old == 1)
return (0);
if (atomic_cmpset_int(count, old, old - 1))
return (1);
}
}
static void
v_init_counters(struct vnode *vp)
{
VNASSERT(vp->v_type == VNON && vp->v_data == NULL && vp->v_iflag == 0,
vp, ("%s called for an initialized vnode", __FUNCTION__));
ASSERT_VI_UNLOCKED(vp, __FUNCTION__);
refcount_init(&vp->v_holdcnt, 1);
refcount_init(&vp->v_usecount, 1);
}
static void
v_incr_usecount_locked(struct vnode *vp)
{
ASSERT_VI_LOCKED(vp, __func__);
if ((vp->v_iflag & VI_OWEINACT) != 0) {
VNASSERT(vp->v_usecount == 0, vp,
("vnode with usecount and VI_OWEINACT set"));
vp->v_iflag &= ~VI_OWEINACT;
}
refcount_acquire(&vp->v_usecount);
v_incr_devcount(vp);
}
/*
* Increment the use count on the vnode, taking care to reference
* the driver's usecount if this is a chardev.
*/
static void
v_incr_usecount(struct vnode *vp)
{
ASSERT_VI_UNLOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
if (vp->v_type != VCHR &&
vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) {
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("vnode with usecount and VI_OWEINACT set"));
} else {
VI_LOCK(vp);
v_incr_usecount_locked(vp);
VI_UNLOCK(vp);
}
}
/*
* Increment si_usecount of the associated device, if any.
*/
static void
v_incr_devcount(struct vnode *vp)
{
ASSERT_VI_LOCKED(vp, __FUNCTION__);
if (vp->v_type == VCHR && vp->v_rdev != NULL) {
dev_lock();
vp->v_rdev->si_usecount++;
dev_unlock();
}
}
/*
* Decrement si_usecount of the associated device, if any.
*/
static void
v_decr_devcount(struct vnode *vp)
{
ASSERT_VI_LOCKED(vp, __FUNCTION__);
if (vp->v_type == VCHR && vp->v_rdev != NULL) {
dev_lock();
vp->v_rdev->si_usecount--;
dev_unlock();
}
}
/*
* Grab a particular vnode from the free list, increment its
* reference count and lock it. VI_DOOMED is set if the vnode
* is being destroyed. Only callers who specify LK_RETRY will
* see doomed vnodes. If inactive processing was delayed in
* vput try to do it here.
*
* Notes on lockless counter manipulation:
* _vhold, vputx and other routines make various decisions based
* on either holdcnt or usecount being 0. As long as either counter
* is not transitioning 0->1 nor 1->0, the manipulation can be done
* with atomic operations. Otherwise the interlock is taken covering
* both the atomic and additional actions.
*/
int
vget(struct vnode *vp, int flags, struct thread *td)
{
int error, oweinact;
VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
("vget: invalid lock operation"));
if ((flags & LK_INTERLOCK) != 0)
ASSERT_VI_LOCKED(vp, __func__);
else
ASSERT_VI_UNLOCKED(vp, __func__);
if ((flags & LK_VNHELD) != 0)
VNASSERT((vp->v_holdcnt > 0), vp,
("vget: LK_VNHELD passed but vnode not held"));
CTR3(KTR_VFS, "%s: vp %p with flags %d", __func__, vp, flags);
if ((flags & LK_VNHELD) == 0)
_vhold(vp, (flags & LK_INTERLOCK) != 0);
if ((error = vn_lock(vp, flags)) != 0) {
vdrop(vp);
CTR2(KTR_VFS, "%s: impossible to lock vnode %p", __func__,
vp);
return (error);
}
if (vp->v_iflag & VI_DOOMED && (flags & LK_RETRY) == 0)
panic("vget: vn_lock failed to return ENOENT\n");
/*
* We don't guarantee that any particular close will
* trigger inactive processing so just make a best effort
* here at preventing a reference to a removed file. If
* we don't succeed no harm is done.
*
* Upgrade our holdcnt to a usecount.
*/
if (vp->v_type == VCHR ||
!vfs_refcount_acquire_if_not_zero(&vp->v_usecount)) {
VI_LOCK(vp);
if ((vp->v_iflag & VI_OWEINACT) == 0) {
oweinact = 0;
} else {
oweinact = 1;
vp->v_iflag &= ~VI_OWEINACT;
}
refcount_acquire(&vp->v_usecount);
v_incr_devcount(vp);
if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
(flags & LK_NOWAIT) == 0)
vinactive(vp, td);
VI_UNLOCK(vp);
}
return (0);
}
/*
* Increase the reference (use) and hold count of a vnode.
* This will also remove the vnode from the free list if it is presently free.
*/
void
vref(struct vnode *vp)
{
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
_vhold(vp, false);
v_incr_usecount(vp);
}
void
vrefl(struct vnode *vp)
{
ASSERT_VI_LOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
_vhold(vp, true);
v_incr_usecount_locked(vp);
}
/*
* Return reference count of a vnode.
*
* The results of this call are only guaranteed when some mechanism is used to
* stop other processes from gaining references to the vnode. This may be the
* case if the caller holds the only reference. This is also useful when stale
* data is acceptable as race conditions may be accounted for by some other
* means.
*/
int
vrefcnt(struct vnode *vp)
{
return (vp->v_usecount);
}
#define VPUTX_VRELE 1
#define VPUTX_VPUT 2
#define VPUTX_VUNREF 3
/*
* Decrement the use and hold counts for a vnode.
*
* See an explanation near vget() as to why atomic operation is safe.
*/
static void
vputx(struct vnode *vp, int func)
{
int error;
KASSERT(vp != NULL, ("vputx: null vp"));
if (func == VPUTX_VUNREF)
ASSERT_VOP_LOCKED(vp, "vunref");
else if (func == VPUTX_VPUT)
ASSERT_VOP_LOCKED(vp, "vput");
else
KASSERT(func == VPUTX_VRELE, ("vputx: wrong func"));
ASSERT_VI_UNLOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
if (vp->v_type != VCHR &&
vfs_refcount_release_if_not_last(&vp->v_usecount)) {
if (func == VPUTX_VPUT)
VOP_UNLOCK(vp, 0);
vdrop(vp);
return;
}
VI_LOCK(vp);
/*
* We want to hold the vnode until the inactive finishes to
* prevent vgone() races. We drop the use count here and the
* hold count below when we're done.
*/
if (!refcount_release(&vp->v_usecount) ||
(vp->v_iflag & VI_DOINGINACT)) {
if (func == VPUTX_VPUT)
VOP_UNLOCK(vp, 0);
v_decr_devcount(vp);
vdropl(vp);
return;
}
v_decr_devcount(vp);
error = 0;
if (vp->v_usecount != 0) {
vn_printf(vp, "vputx: usecount not zero for vnode ");
panic("vputx: usecount not zero");
}
CTR2(KTR_VFS, "%s: return vnode %p to the freelist", __func__, vp);
/*
* We must call VOP_INACTIVE with the node locked. Mark
* as VI_DOINGINACT to avoid recursion.
*/
vp->v_iflag |= VI_OWEINACT;
switch (func) {
case VPUTX_VRELE:
error = vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK);
VI_LOCK(vp);
break;
case VPUTX_VPUT:
if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
error = VOP_LOCK(vp, LK_UPGRADE | LK_INTERLOCK |
LK_NOWAIT);
VI_LOCK(vp);
}
break;
case VPUTX_VUNREF:
if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
error = VOP_LOCK(vp, LK_TRYUPGRADE | LK_INTERLOCK);
VI_LOCK(vp);
}
break;
}
VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp,
("vnode with usecount and VI_OWEINACT set"));
if (error == 0) {
if (vp->v_iflag & VI_OWEINACT)
vinactive(vp, curthread);
if (func != VPUTX_VUNREF)
VOP_UNLOCK(vp, 0);
}
vdropl(vp);
}
/*
* Vnode put/release.
* If count drops to zero, call inactive routine and return to freelist.
*/
void
vrele(struct vnode *vp)
{
vputx(vp, VPUTX_VRELE);
}
/*
* Release an already locked vnode. This give the same effects as
* unlock+vrele(), but takes less time and avoids releasing and
* re-aquiring the lock (as vrele() acquires the lock internally.)
*/
void
vput(struct vnode *vp)
{
vputx(vp, VPUTX_VPUT);
}
/*
* Release an exclusively locked vnode. Do not unlock the vnode lock.
*/
void
vunref(struct vnode *vp)
{
vputx(vp, VPUTX_VUNREF);
}
/*
* Increase the hold count and activate if this is the first reference.
*/
void
_vhold(struct vnode *vp, bool locked)
{
struct mount *mp;
if (locked)
ASSERT_VI_LOCKED(vp, __func__);
else
ASSERT_VI_UNLOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
if (!locked && vfs_refcount_acquire_if_not_zero(&vp->v_holdcnt)) {
VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
("_vhold: vnode with holdcnt is free"));
return;
}
if (!locked)
VI_LOCK(vp);
if ((vp->v_iflag & VI_FREE) == 0) {
refcount_acquire(&vp->v_holdcnt);
if (!locked)
VI_UNLOCK(vp);
return;
}
VNASSERT(vp->v_holdcnt == 0, vp,
("%s: wrong hold count", __func__));
VNASSERT(vp->v_op != NULL, vp,
("%s: vnode already reclaimed.", __func__));
/*
* Remove a vnode from the free list, mark it as in use,
* and put it on the active list.
*/
mp = vp->v_mount;
mtx_lock(&mp->mnt_listmtx);
if ((vp->v_mflag & VMP_TMPMNTFREELIST) != 0) {
TAILQ_REMOVE(&mp->mnt_tmpfreevnodelist, vp, v_actfreelist);
mp->mnt_tmpfreevnodelistsize--;
vp->v_mflag &= ~VMP_TMPMNTFREELIST;
} else {
mtx_lock(&vnode_free_list_mtx);
TAILQ_REMOVE(&vnode_free_list, vp, v_actfreelist);
freevnodes--;
mtx_unlock(&vnode_free_list_mtx);
}
KASSERT((vp->v_iflag & VI_ACTIVE) == 0,
("Activating already active vnode"));
vp->v_iflag &= ~VI_FREE;
vp->v_iflag |= VI_ACTIVE;
TAILQ_INSERT_HEAD(&mp->mnt_activevnodelist, vp, v_actfreelist);
mp->mnt_activevnodelistsize++;
mtx_unlock(&mp->mnt_listmtx);
refcount_acquire(&vp->v_holdcnt);
if (!locked)
VI_UNLOCK(vp);
}
/*
* Drop the hold count of the vnode. If this is the last reference to
* the vnode we place it on the free list unless it has been vgone'd
* (marked VI_DOOMED) in which case we will free it.
*
* Because the vnode vm object keeps a hold reference on the vnode if
* there is at least one resident non-cached page, the vnode cannot
* leave the active list without the page cleanup done.
*/
void
_vdrop(struct vnode *vp, bool locked)
{
struct bufobj *bo;
struct mount *mp;
int active;
if (locked)
ASSERT_VI_LOCKED(vp, __func__);
else
ASSERT_VI_UNLOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
if ((int)vp->v_holdcnt <= 0)
panic("vdrop: holdcnt %d", vp->v_holdcnt);
if (vfs_refcount_release_if_not_last(&vp->v_holdcnt)) {
if (locked)
VI_UNLOCK(vp);
return;
}
if (!locked)
VI_LOCK(vp);
if (refcount_release(&vp->v_holdcnt) == 0) {
VI_UNLOCK(vp);
return;
}
if ((vp->v_iflag & VI_DOOMED) == 0) {
/*
* Mark a vnode as free: remove it from its active list
* and put it up for recycling on the freelist.
*/
VNASSERT(vp->v_op != NULL, vp,
("vdropl: vnode already reclaimed."));
VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
("vnode already free"));
VNASSERT(vp->v_holdcnt == 0, vp,
("vdropl: freeing when we shouldn't"));
active = vp->v_iflag & VI_ACTIVE;
if ((vp->v_iflag & VI_OWEINACT) == 0) {
vp->v_iflag &= ~VI_ACTIVE;
mp = vp->v_mount;
mtx_lock(&mp->mnt_listmtx);
if (active) {
TAILQ_REMOVE(&mp->mnt_activevnodelist, vp,
v_actfreelist);
mp->mnt_activevnodelistsize--;
}
TAILQ_INSERT_TAIL(&mp->mnt_tmpfreevnodelist, vp,
v_actfreelist);
mp->mnt_tmpfreevnodelistsize++;
vp->v_iflag |= VI_FREE;
vp->v_mflag |= VMP_TMPMNTFREELIST;
VI_UNLOCK(vp);
if (mp->mnt_tmpfreevnodelistsize >= mnt_free_list_batch)
vnlru_return_batch_locked(mp);
mtx_unlock(&mp->mnt_listmtx);
} else {
VI_UNLOCK(vp);
atomic_add_long(&free_owe_inact, 1);
}
return;
}
/*
* The vnode has been marked for destruction, so free it.
*
* The vnode will be returned to the zone where it will
* normally remain until it is needed for another vnode. We
* need to cleanup (or verify that the cleanup has already
* been done) any residual data left from its current use
* so as not to contaminate the freshly allocated vnode.
*/
CTR2(KTR_VFS, "%s: destroying the vnode %p", __func__, vp);
atomic_subtract_long(&numvnodes, 1);
bo = &vp->v_bufobj;
VNASSERT((vp->v_iflag & VI_FREE) == 0, vp,
("cleaned vnode still on the free list."));
VNASSERT(vp->v_data == NULL, vp, ("cleaned vnode isn't"));
VNASSERT(vp->v_holdcnt == 0, vp, ("Non-zero hold count"));
VNASSERT(vp->v_usecount == 0, vp, ("Non-zero use count"));
VNASSERT(vp->v_writecount == 0, vp, ("Non-zero write count"));
VNASSERT(bo->bo_numoutput == 0, vp, ("Clean vnode has pending I/O's"));
VNASSERT(bo->bo_clean.bv_cnt == 0, vp, ("cleanbufcnt not 0"));
VNASSERT(pctrie_is_empty(&bo->bo_clean.bv_root), vp,
("clean blk trie not empty"));
VNASSERT(bo->bo_dirty.bv_cnt == 0, vp, ("dirtybufcnt not 0"));
VNASSERT(pctrie_is_empty(&bo->bo_dirty.bv_root), vp,
("dirty blk trie not empty"));
VNASSERT(TAILQ_EMPTY(&vp->v_cache_dst), vp, ("vp has namecache dst"));
VNASSERT(LIST_EMPTY(&vp->v_cache_src), vp, ("vp has namecache src"));
VNASSERT(vp->v_cache_dd == NULL, vp, ("vp has namecache for .."));
VNASSERT(TAILQ_EMPTY(&vp->v_rl.rl_waiters), vp,
("Dangling rangelock waiters"));
VI_UNLOCK(vp);
#ifdef MAC
mac_vnode_destroy(vp);
#endif
if (vp->v_pollinfo != NULL) {
destroy_vpollinfo(vp->v_pollinfo);
vp->v_pollinfo = NULL;
}
#ifdef INVARIANTS
/* XXX Elsewhere we detect an already freed vnode via NULL v_op. */
vp->v_op = NULL;
#endif
bzero(&vp->v_un, sizeof(vp->v_un));
vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
vp->v_iflag = 0;
vp->v_vflag = 0;
bo->bo_flag = 0;
uma_zfree(vnode_zone, vp);
}
/*
* Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
* flags. DOINGINACT prevents us from recursing in calls to vinactive.
* OWEINACT tracks whether a vnode missed a call to inactive due to a
* failed lock upgrade.
*/
void
vinactive(struct vnode *vp, struct thread *td)
{
struct vm_object *obj;
ASSERT_VOP_ELOCKED(vp, "vinactive");
ASSERT_VI_LOCKED(vp, "vinactive");
VNASSERT((vp->v_iflag & VI_DOINGINACT) == 0, vp,
("vinactive: recursed on VI_DOINGINACT"));
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
vp->v_iflag |= VI_DOINGINACT;
vp->v_iflag &= ~VI_OWEINACT;
VI_UNLOCK(vp);
/*
* Before moving off the active list, we must be sure that any
* modified pages are converted into the vnode's dirty
* buffers, since these will no longer be checked once the
* vnode is on the inactive list.
*
* The write-out of the dirty pages is asynchronous. At the
* point that VOP_INACTIVE() is called, there could still be
* pending I/O and dirty pages in the object.
*/
obj = vp->v_object;
if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
VM_OBJECT_WLOCK(obj);
vm_object_page_clean(obj, 0, 0, 0);
VM_OBJECT_WUNLOCK(obj);
}
VOP_INACTIVE(vp, td);
VI_LOCK(vp);
VNASSERT(vp->v_iflag & VI_DOINGINACT, vp,
("vinactive: lost VI_DOINGINACT"));
vp->v_iflag &= ~VI_DOINGINACT;
}
/*
* Remove any vnodes in the vnode table belonging to mount point mp.
*
* If FORCECLOSE is not specified, there should not be any active ones,
* return error if any are found (nb: this is a user error, not a
* system error). If FORCECLOSE is specified, detach any active vnodes
* that are found.
*
* If WRITECLOSE is set, only flush out regular file vnodes open for
* writing.
*
* SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
*
* `rootrefs' specifies the base reference count for the root vnode
* of this filesystem. The root vnode is considered busy if its
* v_usecount exceeds this value. On a successful return, vflush(, td)
* will call vrele() on the root vnode exactly rootrefs times.
* If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
* be zero.
*/
#ifdef DIAGNOSTIC
static int busyprt = 0; /* print out busy vnodes */
SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "Print out busy vnodes");
#endif
int
vflush(struct mount *mp, int rootrefs, int flags, struct thread *td)
{
struct vnode *vp, *mvp, *rootvp = NULL;
struct vattr vattr;
int busy = 0, error;
CTR4(KTR_VFS, "%s: mp %p with rootrefs %d and flags %d", __func__, mp,
rootrefs, flags);
if (rootrefs > 0) {
KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
("vflush: bad args"));
/*
* Get the filesystem root vnode. We can vput() it
* immediately, since with rootrefs > 0, it won't go away.
*/
if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rootvp)) != 0) {
CTR2(KTR_VFS, "%s: vfs_root lookup failed with %d",
__func__, error);
return (error);
}
vput(rootvp);
}
loop:
MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
vholdl(vp);
error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE);
if (error) {
vdrop(vp);
MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
goto loop;
}
/*
* Skip over a vnodes marked VV_SYSTEM.
*/
if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
VOP_UNLOCK(vp, 0);
vdrop(vp);
continue;
}
/*
* If WRITECLOSE is set, flush out unlinked but still open
* files (even if open only for reading) and regular file
* vnodes open for writing.
*/
if (flags & WRITECLOSE) {
if (vp->v_object != NULL) {
VM_OBJECT_WLOCK(vp->v_object);
vm_object_page_clean(vp->v_object, 0, 0, 0);
VM_OBJECT_WUNLOCK(vp->v_object);
}
error = VOP_FSYNC(vp, MNT_WAIT, td);
if (error != 0) {
VOP_UNLOCK(vp, 0);
vdrop(vp);
MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
return (error);
}
error = VOP_GETATTR(vp, &vattr, td->td_ucred);
VI_LOCK(vp);
if ((vp->v_type == VNON ||
(error == 0 && vattr.va_nlink > 0)) &&
(vp->v_writecount == 0 || vp->v_type != VREG)) {
VOP_UNLOCK(vp, 0);
vdropl(vp);
continue;
}
} else
VI_LOCK(vp);
/*
* With v_usecount == 0, all we need to do is clear out the
* vnode data structures and we are done.
*
* If FORCECLOSE is set, forcibly close the vnode.
*/
if (vp->v_usecount == 0 || (flags & FORCECLOSE)) {
vgonel(vp);
} else {
busy++;
#ifdef DIAGNOSTIC
if (busyprt)
vn_printf(vp, "vflush: busy vnode ");
#endif
}
VOP_UNLOCK(vp, 0);
vdropl(vp);
}
if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
/*
* If just the root vnode is busy, and if its refcount
* is equal to `rootrefs', then go ahead and kill it.
*/
VI_LOCK(rootvp);
KASSERT(busy > 0, ("vflush: not busy"));
VNASSERT(rootvp->v_usecount >= rootrefs, rootvp,
("vflush: usecount %d < rootrefs %d",
rootvp->v_usecount, rootrefs));
if (busy == 1 && rootvp->v_usecount == rootrefs) {
VOP_LOCK(rootvp, LK_EXCLUSIVE|LK_INTERLOCK);
vgone(rootvp);
VOP_UNLOCK(rootvp, 0);
busy = 0;
} else
VI_UNLOCK(rootvp);
}
if (busy) {
CTR2(KTR_VFS, "%s: failing as %d vnodes are busy", __func__,
busy);
return (EBUSY);
}
for (; rootrefs > 0; rootrefs--)
vrele(rootvp);
return (0);
}
/*
* Recycle an unused vnode to the front of the free list.
*/
int
vrecycle(struct vnode *vp)
{
int recycled;
VI_LOCK(vp);
recycled = vrecyclel(vp);
VI_UNLOCK(vp);
return (recycled);
}
/*
* vrecycle, with the vp interlock held.
*/
int
vrecyclel(struct vnode *vp)
{
int recycled;
ASSERT_VOP_ELOCKED(vp, __func__);
ASSERT_VI_LOCKED(vp, __func__);
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
recycled = 0;
if (vp->v_usecount == 0) {
recycled = 1;
vgonel(vp);
}
return (recycled);
}
/*
* Eliminate all activity associated with a vnode
* in preparation for reuse.
*/
void
vgone(struct vnode *vp)
{
VI_LOCK(vp);
vgonel(vp);
VI_UNLOCK(vp);
}
static void
notify_lowervp_vfs_dummy(struct mount *mp __unused,
struct vnode *lowervp __unused)
{
}
/*
* Notify upper mounts about reclaimed or unlinked vnode.
*/
void
vfs_notify_upper(struct vnode *vp, int event)
{
static struct vfsops vgonel_vfsops = {
.vfs_reclaim_lowervp = notify_lowervp_vfs_dummy,
.vfs_unlink_lowervp = notify_lowervp_vfs_dummy,
};
struct mount *mp, *ump, *mmp;
mp = vp->v_mount;
if (mp == NULL)
return;
MNT_ILOCK(mp);
if (TAILQ_EMPTY(&mp->mnt_uppers))
goto unlock;
MNT_IUNLOCK(mp);
mmp = malloc(sizeof(struct mount), M_TEMP, M_WAITOK | M_ZERO);
mmp->mnt_op = &vgonel_vfsops;
mmp->mnt_kern_flag |= MNTK_MARKER;
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_VGONE_UPPER;
for (ump = TAILQ_FIRST(&mp->mnt_uppers); ump != NULL;) {
if ((ump->mnt_kern_flag & MNTK_MARKER) != 0) {
ump = TAILQ_NEXT(ump, mnt_upper_link);
continue;
}
TAILQ_INSERT_AFTER(&mp->mnt_uppers, ump, mmp, mnt_upper_link);
MNT_IUNLOCK(mp);
switch (event) {
case VFS_NOTIFY_UPPER_RECLAIM:
VFS_RECLAIM_LOWERVP(ump, vp);
break;
case VFS_NOTIFY_UPPER_UNLINK:
VFS_UNLINK_LOWERVP(ump, vp);
break;
default:
KASSERT(0, ("invalid event %d", event));
break;
}
MNT_ILOCK(mp);
ump = TAILQ_NEXT(mmp, mnt_upper_link);
TAILQ_REMOVE(&mp->mnt_uppers, mmp, mnt_upper_link);
}
free(mmp, M_TEMP);
mp->mnt_kern_flag &= ~MNTK_VGONE_UPPER;
if ((mp->mnt_kern_flag & MNTK_VGONE_WAITER) != 0) {
mp->mnt_kern_flag &= ~MNTK_VGONE_WAITER;
wakeup(&mp->mnt_uppers);
}
unlock:
MNT_IUNLOCK(mp);
}
/*
* vgone, with the vp interlock held.
*/
static void
vgonel(struct vnode *vp)
{
struct thread *td;
int oweinact;
int active;
struct mount *mp;
ASSERT_VOP_ELOCKED(vp, "vgonel");
ASSERT_VI_LOCKED(vp, "vgonel");
VNASSERT(vp->v_holdcnt, vp,
("vgonel: vp %p has no reference.", vp));
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
td = curthread;
/*
* Don't vgonel if we're already doomed.
*/
if (vp->v_iflag & VI_DOOMED)
return;
vp->v_iflag |= VI_DOOMED;
/*
* Check to see if the vnode is in use. If so, we have to call
* VOP_CLOSE() and VOP_INACTIVE().
*/
active = vp->v_usecount;
oweinact = (vp->v_iflag & VI_OWEINACT);
VI_UNLOCK(vp);
vfs_notify_upper(vp, VFS_NOTIFY_UPPER_RECLAIM);
/*
* If purging an active vnode, it must be closed and
* deactivated before being reclaimed.
*/
if (active)
VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
if (oweinact || active) {
VI_LOCK(vp);
if ((vp->v_iflag & VI_DOINGINACT) == 0)
vinactive(vp, td);
VI_UNLOCK(vp);
}
if (vp->v_type == VSOCK)
vfs_unp_reclaim(vp);
/*
* Clean out any buffers associated with the vnode.
* If the flush fails, just toss the buffers.
*/
mp = NULL;
if (!TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd))
(void) vn_start_secondary_write(vp, &mp, V_WAIT);
if (vinvalbuf(vp, V_SAVE, 0, 0) != 0) {
while (vinvalbuf(vp, 0, 0, 0) != 0)
;
}
BO_LOCK(&vp->v_bufobj);
KASSERT(TAILQ_EMPTY(&vp->v_bufobj.bo_dirty.bv_hd) &&
vp->v_bufobj.bo_dirty.bv_cnt == 0 &&
TAILQ_EMPTY(&vp->v_bufobj.bo_clean.bv_hd) &&
vp->v_bufobj.bo_clean.bv_cnt == 0,
("vp %p bufobj not invalidated", vp));
/*
* For VMIO bufobj, BO_DEAD is set in vm_object_terminate()
* after the object's page queue is flushed.
*/
if (vp->v_bufobj.bo_object == NULL)
vp->v_bufobj.bo_flag |= BO_DEAD;
BO_UNLOCK(&vp->v_bufobj);
/*
* Reclaim the vnode.
*/
if (VOP_RECLAIM(vp, td))
panic("vgone: cannot reclaim");
if (mp != NULL)
vn_finished_secondary_write(mp);
VNASSERT(vp->v_object == NULL, vp,
("vop_reclaim left v_object vp=%p, tag=%s", vp, vp->v_tag));
/*
* Clear the advisory locks and wake up waiting threads.
*/
(void)VOP_ADVLOCKPURGE(vp);
vp->v_lockf = NULL;
/*
* Delete from old mount point vnode list.
*/
delmntque(vp);
cache_purge(vp);
/*
* Done with purge, reset to the standard lock and invalidate
* the vnode.
*/
VI_LOCK(vp);
vp->v_vnlock = &vp->v_lock;
vp->v_op = &dead_vnodeops;
vp->v_tag = "none";
vp->v_type = VBAD;
}
/*
* Calculate the total number of references to a special device.
*/
int
vcount(struct vnode *vp)
{
int count;
dev_lock();
count = vp->v_rdev->si_usecount;
dev_unlock();
return (count);
}
/*
* Same as above, but using the struct cdev *as argument
*/
int
count_dev(struct cdev *dev)
{
int count;
dev_lock();
count = dev->si_usecount;
dev_unlock();
return(count);
}
/*
* Print out a description of a vnode.
*/
static char *typename[] =
{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD",
"VMARKER"};
void
vn_printf(struct vnode *vp, const char *fmt, ...)
{
va_list ap;
char buf[256], buf2[16];
u_long flags;
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
printf("%p: ", (void *)vp);
printf("tag %s, type %s\n", vp->v_tag, typename[vp->v_type]);
printf(" usecount %d, writecount %d, refcount %d mountedhere %p\n",
vp->v_usecount, vp->v_writecount, vp->v_holdcnt, vp->v_mountedhere);
buf[0] = '\0';
buf[1] = '\0';
if (vp->v_vflag & VV_ROOT)
strlcat(buf, "|VV_ROOT", sizeof(buf));
if (vp->v_vflag & VV_ISTTY)
strlcat(buf, "|VV_ISTTY", sizeof(buf));
if (vp->v_vflag & VV_NOSYNC)
strlcat(buf, "|VV_NOSYNC", sizeof(buf));
if (vp->v_vflag & VV_ETERNALDEV)
strlcat(buf, "|VV_ETERNALDEV", sizeof(buf));
if (vp->v_vflag & VV_CACHEDLABEL)
strlcat(buf, "|VV_CACHEDLABEL", sizeof(buf));
if (vp->v_vflag & VV_TEXT)
strlcat(buf, "|VV_TEXT", sizeof(buf));
if (vp->v_vflag & VV_COPYONWRITE)
strlcat(buf, "|VV_COPYONWRITE", sizeof(buf));
if (vp->v_vflag & VV_SYSTEM)
strlcat(buf, "|VV_SYSTEM", sizeof(buf));
if (vp->v_vflag & VV_PROCDEP)
strlcat(buf, "|VV_PROCDEP", sizeof(buf));
if (vp->v_vflag & VV_NOKNOTE)
strlcat(buf, "|VV_NOKNOTE", sizeof(buf));
if (vp->v_vflag & VV_DELETED)
strlcat(buf, "|VV_DELETED", sizeof(buf));
if (vp->v_vflag & VV_MD)
strlcat(buf, "|VV_MD", sizeof(buf));
if (vp->v_vflag & VV_FORCEINSMQ)
strlcat(buf, "|VV_FORCEINSMQ", sizeof(buf));
flags = vp->v_vflag & ~(VV_ROOT | VV_ISTTY | VV_NOSYNC | VV_ETERNALDEV |
VV_CACHEDLABEL | VV_TEXT | VV_COPYONWRITE | VV_SYSTEM | VV_PROCDEP |
VV_NOKNOTE | VV_DELETED | VV_MD | VV_FORCEINSMQ);
if (flags != 0) {
snprintf(buf2, sizeof(buf2), "|VV(0x%lx)", flags);
strlcat(buf, buf2, sizeof(buf));
}
if (vp->v_iflag & VI_MOUNT)
strlcat(buf, "|VI_MOUNT", sizeof(buf));
if (vp->v_iflag & VI_DOOMED)
strlcat(buf, "|VI_DOOMED", sizeof(buf));
if (vp->v_iflag & VI_FREE)
strlcat(buf, "|VI_FREE", sizeof(buf));
if (vp->v_iflag & VI_ACTIVE)
strlcat(buf, "|VI_ACTIVE", sizeof(buf));
if (vp->v_iflag & VI_DOINGINACT)
strlcat(buf, "|VI_DOINGINACT", sizeof(buf));
if (vp->v_iflag & VI_OWEINACT)
strlcat(buf, "|VI_OWEINACT", sizeof(buf));
flags = vp->v_iflag & ~(VI_MOUNT | VI_DOOMED | VI_FREE |
VI_ACTIVE | VI_DOINGINACT | VI_OWEINACT);
if (flags != 0) {
snprintf(buf2, sizeof(buf2), "|VI(0x%lx)", flags);
strlcat(buf, buf2, sizeof(buf));
}
printf(" flags (%s)\n", buf + 1);
if (mtx_owned(VI_MTX(vp)))
printf(" VI_LOCKed");
if (vp->v_object != NULL)
printf(" v_object %p ref %d pages %d "
"cleanbuf %d dirtybuf %d\n",
vp->v_object, vp->v_object->ref_count,
vp->v_object->resident_page_count,
vp->v_bufobj.bo_clean.bv_cnt,
vp->v_bufobj.bo_dirty.bv_cnt);
printf(" ");
lockmgr_printinfo(vp->v_vnlock);
if (vp->v_data != NULL)
VOP_PRINT(vp);
}
#ifdef DDB
/*
* List all of the locked vnodes in the system.
* Called when debugging the kernel.
*/
DB_SHOW_COMMAND(lockedvnods, lockedvnodes)
{
struct mount *mp;
struct vnode *vp;
/*
* Note: because this is DDB, we can't obey the locking semantics
* for these structures, which means we could catch an inconsistent
* state and dereference a nasty pointer. Not much to be done
* about that.
*/
db_printf("Locked vnodes\n");
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
if (vp->v_type != VMARKER && VOP_ISLOCKED(vp))
vn_printf(vp, "vnode ");
}
}
}
/*
* Show details about the given vnode.
*/
DB_SHOW_COMMAND(vnode, db_show_vnode)
{
struct vnode *vp;
if (!have_addr)
return;
vp = (struct vnode *)addr;
vn_printf(vp, "vnode ");
}
/*
* Show details about the given mount point.
*/
DB_SHOW_COMMAND(mount, db_show_mount)
{
struct mount *mp;
struct vfsopt *opt;
struct statfs *sp;
struct vnode *vp;
char buf[512];
uint64_t mflags;
u_int flags;
if (!have_addr) {
/* No address given, print short info about all mount points. */
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
db_printf("%p %s on %s (%s)\n", mp,
mp->mnt_stat.f_mntfromname,
mp->mnt_stat.f_mntonname,
mp->mnt_stat.f_fstypename);
if (db_pager_quit)
break;
}
db_printf("\nMore info: show mount <addr>\n");
return;
}
mp = (struct mount *)addr;
db_printf("%p %s on %s (%s)\n", mp, mp->mnt_stat.f_mntfromname,
mp->mnt_stat.f_mntonname, mp->mnt_stat.f_fstypename);
buf[0] = '\0';
mflags = mp->mnt_flag;
#define MNT_FLAG(flag) do { \
if (mflags & (flag)) { \
if (buf[0] != '\0') \
strlcat(buf, ", ", sizeof(buf)); \
strlcat(buf, (#flag) + 4, sizeof(buf)); \
mflags &= ~(flag); \
} \
} while (0)
MNT_FLAG(MNT_RDONLY);
MNT_FLAG(MNT_SYNCHRONOUS);
MNT_FLAG(MNT_NOEXEC);
MNT_FLAG(MNT_NOSUID);
MNT_FLAG(MNT_NFS4ACLS);
MNT_FLAG(MNT_UNION);
MNT_FLAG(MNT_ASYNC);
MNT_FLAG(MNT_SUIDDIR);
MNT_FLAG(MNT_SOFTDEP);
MNT_FLAG(MNT_NOSYMFOLLOW);
MNT_FLAG(MNT_GJOURNAL);
MNT_FLAG(MNT_MULTILABEL);
MNT_FLAG(MNT_ACLS);
MNT_FLAG(MNT_NOATIME);
MNT_FLAG(MNT_NOCLUSTERR);
MNT_FLAG(MNT_NOCLUSTERW);
MNT_FLAG(MNT_SUJ);
MNT_FLAG(MNT_EXRDONLY);
MNT_FLAG(MNT_EXPORTED);
MNT_FLAG(MNT_DEFEXPORTED);
MNT_FLAG(MNT_EXPORTANON);
MNT_FLAG(MNT_EXKERB);
MNT_FLAG(MNT_EXPUBLIC);
MNT_FLAG(MNT_LOCAL);
MNT_FLAG(MNT_QUOTA);
MNT_FLAG(MNT_ROOTFS);
MNT_FLAG(MNT_USER);
MNT_FLAG(MNT_IGNORE);
MNT_FLAG(MNT_UPDATE);
MNT_FLAG(MNT_DELEXPORT);
MNT_FLAG(MNT_RELOAD);
MNT_FLAG(MNT_FORCE);
MNT_FLAG(MNT_SNAPSHOT);
MNT_FLAG(MNT_BYFSID);
#undef MNT_FLAG
if (mflags != 0) {
if (buf[0] != '\0')
strlcat(buf, ", ", sizeof(buf));
snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
"0x%016jx", mflags);
}
db_printf(" mnt_flag = %s\n", buf);
buf[0] = '\0';
flags = mp->mnt_kern_flag;
#define MNT_KERN_FLAG(flag) do { \
if (flags & (flag)) { \
if (buf[0] != '\0') \
strlcat(buf, ", ", sizeof(buf)); \
strlcat(buf, (#flag) + 5, sizeof(buf)); \
flags &= ~(flag); \
} \
} while (0)
MNT_KERN_FLAG(MNTK_UNMOUNTF);
MNT_KERN_FLAG(MNTK_ASYNC);
MNT_KERN_FLAG(MNTK_SOFTDEP);
MNT_KERN_FLAG(MNTK_NOINSMNTQ);
MNT_KERN_FLAG(MNTK_DRAINING);
MNT_KERN_FLAG(MNTK_REFEXPIRE);
MNT_KERN_FLAG(MNTK_EXTENDED_SHARED);
MNT_KERN_FLAG(MNTK_SHARED_WRITES);
MNT_KERN_FLAG(MNTK_NO_IOPF);
MNT_KERN_FLAG(MNTK_VGONE_UPPER);
MNT_KERN_FLAG(MNTK_VGONE_WAITER);
MNT_KERN_FLAG(MNTK_LOOKUP_EXCL_DOTDOT);
MNT_KERN_FLAG(MNTK_MARKER);
MNT_KERN_FLAG(MNTK_USES_BCACHE);
MNT_KERN_FLAG(MNTK_NOASYNC);
MNT_KERN_FLAG(MNTK_UNMOUNT);
MNT_KERN_FLAG(MNTK_MWAIT);
MNT_KERN_FLAG(MNTK_SUSPEND);
MNT_KERN_FLAG(MNTK_SUSPEND2);
MNT_KERN_FLAG(MNTK_SUSPENDED);
MNT_KERN_FLAG(MNTK_LOOKUP_SHARED);
MNT_KERN_FLAG(MNTK_NOKNOTE);
#undef MNT_KERN_FLAG
if (flags != 0) {
if (buf[0] != '\0')
strlcat(buf, ", ", sizeof(buf));
snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf),
"0x%08x", flags);
}
db_printf(" mnt_kern_flag = %s\n", buf);
db_printf(" mnt_opt = ");
opt = TAILQ_FIRST(mp->mnt_opt);
if (opt != NULL) {
db_printf("%s", opt->name);
opt = TAILQ_NEXT(opt, link);
while (opt != NULL) {
db_printf(", %s", opt->name);
opt = TAILQ_NEXT(opt, link);
}
}
db_printf("\n");
sp = &mp->mnt_stat;
db_printf(" mnt_stat = { version=%u type=%u flags=0x%016jx "
"bsize=%ju iosize=%ju blocks=%ju bfree=%ju bavail=%jd files=%ju "
"ffree=%jd syncwrites=%ju asyncwrites=%ju syncreads=%ju "
"asyncreads=%ju namemax=%u owner=%u fsid=[%d, %d] }\n",
(u_int)sp->f_version, (u_int)sp->f_type, (uintmax_t)sp->f_flags,
(uintmax_t)sp->f_bsize, (uintmax_t)sp->f_iosize,
(uintmax_t)sp->f_blocks, (uintmax_t)sp->f_bfree,
(intmax_t)sp->f_bavail, (uintmax_t)sp->f_files,
(intmax_t)sp->f_ffree, (uintmax_t)sp->f_syncwrites,
(uintmax_t)sp->f_asyncwrites, (uintmax_t)sp->f_syncreads,
(uintmax_t)sp->f_asyncreads, (u_int)sp->f_namemax,
(u_int)sp->f_owner, (int)sp->f_fsid.val[0], (int)sp->f_fsid.val[1]);
db_printf(" mnt_cred = { uid=%u ruid=%u",
(u_int)mp->mnt_cred->cr_uid, (u_int)mp->mnt_cred->cr_ruid);
if (jailed(mp->mnt_cred))
db_printf(", jail=%d", mp->mnt_cred->cr_prison->pr_id);
db_printf(" }\n");
db_printf(" mnt_ref = %d\n", mp->mnt_ref);
db_printf(" mnt_gen = %d\n", mp->mnt_gen);
db_printf(" mnt_nvnodelistsize = %d\n", mp->mnt_nvnodelistsize);
db_printf(" mnt_activevnodelistsize = %d\n",
mp->mnt_activevnodelistsize);
db_printf(" mnt_writeopcount = %d\n", mp->mnt_writeopcount);
db_printf(" mnt_maxsymlinklen = %d\n", mp->mnt_maxsymlinklen);
db_printf(" mnt_iosize_max = %d\n", mp->mnt_iosize_max);
db_printf(" mnt_hashseed = %u\n", mp->mnt_hashseed);
db_printf(" mnt_lockref = %d\n", mp->mnt_lockref);
db_printf(" mnt_secondary_writes = %d\n", mp->mnt_secondary_writes);
db_printf(" mnt_secondary_accwrites = %d\n",
mp->mnt_secondary_accwrites);
db_printf(" mnt_gjprovider = %s\n",
mp->mnt_gjprovider != NULL ? mp->mnt_gjprovider : "NULL");
db_printf("\n\nList of active vnodes\n");
TAILQ_FOREACH(vp, &mp->mnt_activevnodelist, v_actfreelist) {
if (vp->v_type != VMARKER) {
vn_printf(vp, "vnode ");
if (db_pager_quit)
break;
}
}
db_printf("\n\nList of inactive vnodes\n");
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
if (vp->v_type != VMARKER && (vp->v_iflag & VI_ACTIVE) == 0) {
vn_printf(vp, "vnode ");
if (db_pager_quit)
break;
}
}
}
#endif /* DDB */
/*
* Fill in a struct xvfsconf based on a struct vfsconf.
*/
static int
vfsconf2x(struct sysctl_req *req, struct vfsconf *vfsp)
{
struct xvfsconf xvfsp;
bzero(&xvfsp, sizeof(xvfsp));
strcpy(xvfsp.vfc_name, vfsp->vfc_name);
xvfsp.vfc_typenum = vfsp->vfc_typenum;
xvfsp.vfc_refcount = vfsp->vfc_refcount;
xvfsp.vfc_flags = vfsp->vfc_flags;
/*
* These are unused in userland, we keep them
* to not break binary compatibility.
*/
xvfsp.vfc_vfsops = NULL;
xvfsp.vfc_next = NULL;
return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
}
#ifdef COMPAT_FREEBSD32
struct xvfsconf32 {
uint32_t vfc_vfsops;
char vfc_name[MFSNAMELEN];
int32_t vfc_typenum;
int32_t vfc_refcount;
int32_t vfc_flags;
uint32_t vfc_next;
};
static int
vfsconf2x32(struct sysctl_req *req, struct vfsconf *vfsp)
{
struct xvfsconf32 xvfsp;
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;
xvfsp.vfc_vfsops = 0;
xvfsp.vfc_next = 0;
return (SYSCTL_OUT(req, &xvfsp, sizeof(xvfsp)));
}
#endif
/*
* Top level filesystem related information gathering.
*/
static int
sysctl_vfs_conflist(SYSCTL_HANDLER_ARGS)
{
struct vfsconf *vfsp;
int error;
error = 0;
vfsconf_slock();
TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
#ifdef COMPAT_FREEBSD32
if (req->flags & SCTL_MASK32)
error = vfsconf2x32(req, vfsp);
else
#endif
error = vfsconf2x(req, vfsp);
if (error)
break;
}
vfsconf_sunlock();
return (error);
}
SYSCTL_PROC(_vfs, OID_AUTO, conflist, CTLTYPE_OPAQUE | CTLFLAG_RD |
CTLFLAG_MPSAFE, NULL, 0, sysctl_vfs_conflist,
"S,xvfsconf", "List of all configured filesystems");
#ifndef BURN_BRIDGES
static int sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS);
static int
vfs_sysctl(SYSCTL_HANDLER_ARGS)
{
int *name = (int *)arg1 - 1; /* XXX */
u_int namelen = arg2 + 1; /* XXX */
struct vfsconf *vfsp;
log(LOG_WARNING, "userland calling deprecated sysctl, "
"please rebuild world\n");
#if 1 || defined(COMPAT_PRELITE2)
/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
if (namelen == 1)
return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
#endif
switch (name[1]) {
case VFS_MAXTYPENUM:
if (namelen != 2)
return (ENOTDIR);
return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
case VFS_CONF:
if (namelen != 3)
return (ENOTDIR); /* overloaded */
vfsconf_slock();
TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
if (vfsp->vfc_typenum == name[2])
break;
}
vfsconf_sunlock();
if (vfsp == NULL)
return (EOPNOTSUPP);
#ifdef COMPAT_FREEBSD32
if (req->flags & SCTL_MASK32)
return (vfsconf2x32(req, vfsp));
else
#endif
return (vfsconf2x(req, vfsp));
}
return (EOPNOTSUPP);
}
static SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD | CTLFLAG_SKIP |
CTLFLAG_MPSAFE, vfs_sysctl,
"Generic filesystem");
#if 1 || defined(COMPAT_PRELITE2)
static int
sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
{
int error;
struct vfsconf *vfsp;
struct ovfsconf ovfs;
vfsconf_slock();
TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) {
bzero(&ovfs, sizeof(ovfs));
ovfs.vfc_vfsops = vfsp->vfc_vfsops; /* XXX used as flag */
strcpy(ovfs.vfc_name, vfsp->vfc_name);
ovfs.vfc_index = vfsp->vfc_typenum;
ovfs.vfc_refcount = vfsp->vfc_refcount;
ovfs.vfc_flags = vfsp->vfc_flags;
error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
if (error != 0) {
vfsconf_sunlock();
return (error);
}
}
vfsconf_sunlock();
return (0);
}
#endif /* 1 || COMPAT_PRELITE2 */
#endif /* !BURN_BRIDGES */
#define KINFO_VNODESLOP 10
#ifdef notyet
/*
* Dump vnode list (via sysctl).
*/
/* ARGSUSED */
static int
sysctl_vnode(SYSCTL_HANDLER_ARGS)
{
struct xvnode *xvn;
struct mount *mp;
struct vnode *vp;
int error, len, n;
/*
* Stale numvnodes access is not fatal here.
*/
req->lock = 0;
len = (numvnodes + KINFO_VNODESLOP) * sizeof *xvn;
if (!req->oldptr)
/* Make an estimate */
return (SYSCTL_OUT(req, 0, len));
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
xvn = malloc(len, M_TEMP, M_ZERO | M_WAITOK);
n = 0;
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK))
continue;
MNT_ILOCK(mp);
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
if (n == len)
break;
vref(vp);
xvn[n].xv_size = sizeof *xvn;
xvn[n].xv_vnode = vp;
xvn[n].xv_id = 0; /* XXX compat */
#define XV_COPY(field) xvn[n].xv_##field = vp->v_##field
XV_COPY(usecount);
XV_COPY(writecount);
XV_COPY(holdcnt);
XV_COPY(mount);
XV_COPY(numoutput);
XV_COPY(type);
#undef XV_COPY
xvn[n].xv_flag = vp->v_vflag;
switch (vp->v_type) {
case VREG:
case VDIR:
case VLNK:
break;
case VBLK:
case VCHR:
if (vp->v_rdev == NULL) {
vrele(vp);
continue;
}
xvn[n].xv_dev = dev2udev(vp->v_rdev);
break;
case VSOCK:
xvn[n].xv_socket = vp->v_socket;
break;
case VFIFO:
xvn[n].xv_fifo = vp->v_fifoinfo;
break;
case VNON:
case VBAD:
default:
/* shouldn't happen? */
vrele(vp);
continue;
}
vrele(vp);
++n;
}
MNT_IUNLOCK(mp);
mtx_lock(&mountlist_mtx);
vfs_unbusy(mp);
if (n == len)
break;
}
mtx_unlock(&mountlist_mtx);
error = SYSCTL_OUT(req, xvn, n * sizeof *xvn);
free(xvn, M_TEMP);
return (error);
}
SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE | CTLFLAG_RD |
CTLFLAG_MPSAFE, 0, 0, sysctl_vnode, "S,xvnode",
"");
#endif
static void
unmount_or_warn(struct mount *mp)
{
int error;
error = dounmount(mp, MNT_FORCE, curthread);
if (error != 0) {
printf("unmount of %s failed (", mp->mnt_stat.f_mntonname);
if (error == EBUSY)
printf("BUSY)\n");
else
printf("%d)\n", error);
}
}
/*
* Unmount all filesystems. The list is traversed in reverse order
* of mounting to avoid dependencies.
*/
void
vfs_unmountall(void)
{
struct mount *mp, *tmp;
CTR1(KTR_VFS, "%s: unmounting all filesystems", __func__);
/*
* Since this only runs when rebooting, it is not interlocked.
*/
TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, tmp) {
vfs_ref(mp);
/*
* Forcibly unmounting "/dev" before "/" would prevent clean
* unmount of the latter.
*/
if (mp == rootdevmp)
continue;
unmount_or_warn(mp);
}
if (rootdevmp != NULL)
unmount_or_warn(rootdevmp);
}
/*
* perform msync on all vnodes under a mount point
* the mount point must be locked.
*/
void
vfs_msync(struct mount *mp, int flags)
{
struct vnode *vp, *mvp;
struct vm_object *obj;
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
vnlru_return_batch(mp);
MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) {
obj = vp->v_object;
if (obj != NULL && (obj->flags & OBJ_MIGHTBEDIRTY) != 0 &&
(flags == MNT_WAIT || VOP_ISLOCKED(vp) == 0)) {
if (!vget(vp,
LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
curthread)) {
if (vp->v_vflag & VV_NOSYNC) { /* unlinked */
vput(vp);
continue;
}
obj = vp->v_object;
if (obj != NULL) {
VM_OBJECT_WLOCK(obj);
vm_object_page_clean(obj, 0, 0,
flags == MNT_WAIT ?
OBJPC_SYNC : OBJPC_NOSYNC);
VM_OBJECT_WUNLOCK(obj);
}
vput(vp);
}
} else
VI_UNLOCK(vp);
}
}
static void
destroy_vpollinfo_free(struct vpollinfo *vi)
{
knlist_destroy(&vi->vpi_selinfo.si_note);
mtx_destroy(&vi->vpi_lock);
uma_zfree(vnodepoll_zone, vi);
}
static void
destroy_vpollinfo(struct vpollinfo *vi)
{
knlist_clear(&vi->vpi_selinfo.si_note, 1);
seldrain(&vi->vpi_selinfo);
destroy_vpollinfo_free(vi);
}
/*
* Initialize per-vnode helper structure to hold poll-related state.
*/
void
v_addpollinfo(struct vnode *vp)
{
struct vpollinfo *vi;
if (vp->v_pollinfo != NULL)
return;
vi = uma_zalloc(vnodepoll_zone, M_WAITOK | M_ZERO);
mtx_init(&vi->vpi_lock, "vnode pollinfo", NULL, MTX_DEF);
knlist_init(&vi->vpi_selinfo.si_note, vp, vfs_knllock,
vfs_knlunlock, vfs_knl_assert_locked, vfs_knl_assert_unlocked);
VI_LOCK(vp);
if (vp->v_pollinfo != NULL) {
VI_UNLOCK(vp);
destroy_vpollinfo_free(vi);
return;
}
vp->v_pollinfo = vi;
VI_UNLOCK(vp);
}
/*
* Record a process's interest in events which might happen to
* a vnode. Because poll uses the historic select-style interface
* internally, this routine serves as both the ``check for any
* pending events'' and the ``record my interest in future events''
* functions. (These are done together, while the lock is held,
* to avoid race conditions.)
*/
int
vn_pollrecord(struct vnode *vp, struct thread *td, int events)
{
v_addpollinfo(vp);
mtx_lock(&vp->v_pollinfo->vpi_lock);
if (vp->v_pollinfo->vpi_revents & events) {
/*
* This leaves events we are not interested
* in available for the other process which
* which presumably had requested them
* (otherwise they would never have been
* recorded).
*/
events &= vp->v_pollinfo->vpi_revents;
vp->v_pollinfo->vpi_revents &= ~events;
mtx_unlock(&vp->v_pollinfo->vpi_lock);
return (events);
}
vp->v_pollinfo->vpi_events |= events;
selrecord(td, &vp->v_pollinfo->vpi_selinfo);
mtx_unlock(&vp->v_pollinfo->vpi_lock);
return (0);
}
/*
* Routine to create and manage a filesystem syncer vnode.
*/
#define sync_close ((int (*)(struct vop_close_args *))nullop)
static int sync_fsync(struct vop_fsync_args *);
static int sync_inactive(struct vop_inactive_args *);
static int sync_reclaim(struct vop_reclaim_args *);
static struct vop_vector sync_vnodeops = {
.vop_bypass = VOP_EOPNOTSUPP,
.vop_close = sync_close, /* close */
.vop_fsync = sync_fsync, /* fsync */
.vop_inactive = sync_inactive, /* inactive */
.vop_reclaim = sync_reclaim, /* reclaim */
.vop_lock1 = vop_stdlock, /* lock */
.vop_unlock = vop_stdunlock, /* unlock */
.vop_islocked = vop_stdislocked, /* islocked */
};
/*
* Create a new filesystem syncer vnode for the specified mount point.
*/
void
vfs_allocate_syncvnode(struct mount *mp)
{
struct vnode *vp;
struct bufobj *bo;
static long start, incr, next;
int error;
/* Allocate a new vnode */
error = getnewvnode("syncer", mp, &sync_vnodeops, &vp);
if (error != 0)
panic("vfs_allocate_syncvnode: getnewvnode() failed");
vp->v_type = VNON;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
vp->v_vflag |= VV_FORCEINSMQ;
error = insmntque(vp, mp);
if (error != 0)
panic("vfs_allocate_syncvnode: insmntque() failed");
vp->v_vflag &= ~VV_FORCEINSMQ;
VOP_UNLOCK(vp, 0);
/*
* Place the vnode onto the syncer worklist. We attempt to
* scatter them about on the list so that they will go off
* at evenly distributed times even if all the filesystems
* are mounted at once.
*/
next += incr;
if (next == 0 || next > syncer_maxdelay) {
start /= 2;
incr /= 2;
if (start == 0) {
start = syncer_maxdelay / 2;
incr = syncer_maxdelay;
}
next = start;
}
bo = &vp->v_bufobj;
BO_LOCK(bo);
vn_syncer_add_to_worklist(bo, syncdelay > 0 ? next % syncdelay : 0);
/* XXX - vn_syncer_add_to_worklist() also grabs and drops sync_mtx. */
mtx_lock(&sync_mtx);
sync_vnode_count++;
if (mp->mnt_syncer == NULL) {
mp->mnt_syncer = vp;
vp = NULL;
}
mtx_unlock(&sync_mtx);
BO_UNLOCK(bo);
if (vp != NULL) {
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
vgone(vp);
vput(vp);
}
}
void
vfs_deallocate_syncvnode(struct mount *mp)
{
struct vnode *vp;
mtx_lock(&sync_mtx);
vp = mp->mnt_syncer;
if (vp != NULL)
mp->mnt_syncer = NULL;
mtx_unlock(&sync_mtx);
if (vp != NULL)
vrele(vp);
}
/*
* Do a lazy sync of the filesystem.
*/
static int
sync_fsync(struct vop_fsync_args *ap)
{
struct vnode *syncvp = ap->a_vp;
struct mount *mp = syncvp->v_mount;
int error, save;
struct bufobj *bo;
/*
* We only need to do something if this is a lazy evaluation.
*/
if (ap->a_waitfor != MNT_LAZY)
return (0);
/*
* Move ourselves to the back of the sync list.
*/
bo = &syncvp->v_bufobj;
BO_LOCK(bo);
vn_syncer_add_to_worklist(bo, syncdelay);
BO_UNLOCK(bo);
/*
* Walk the list of vnodes pushing all that are dirty and
* not already on the sync list.
*/
if (vfs_busy(mp, MBF_NOWAIT) != 0)
return (0);
if (vn_start_write(NULL, &mp, V_NOWAIT) != 0) {
vfs_unbusy(mp);
return (0);
}
save = curthread_pflags_set(TDP_SYNCIO);
vfs_msync(mp, MNT_NOWAIT);
error = VFS_SYNC(mp, MNT_LAZY);
curthread_pflags_restore(save);
vn_finished_write(mp);
vfs_unbusy(mp);
return (error);
}
/*
* The syncer vnode is no referenced.
*/
static int
sync_inactive(struct vop_inactive_args *ap)
{
vgone(ap->a_vp);
return (0);
}
/*
* The syncer vnode is no longer needed and is being decommissioned.
*
* Modifications to the worklist must be protected by sync_mtx.
*/
static int
sync_reclaim(struct vop_reclaim_args *ap)
{
struct vnode *vp = ap->a_vp;
struct bufobj *bo;
bo = &vp->v_bufobj;
BO_LOCK(bo);
mtx_lock(&sync_mtx);
if (vp->v_mount->mnt_syncer == vp)
vp->v_mount->mnt_syncer = NULL;
if (bo->bo_flag & BO_ONWORKLST) {
LIST_REMOVE(bo, bo_synclist);
syncer_worklist_len--;
sync_vnode_count--;
bo->bo_flag &= ~BO_ONWORKLST;
}
mtx_unlock(&sync_mtx);
BO_UNLOCK(bo);
return (0);
}
/*
* Check if vnode represents a disk device
*/
int
vn_isdisk(struct vnode *vp, int *errp)
{
int error;
if (vp->v_type != VCHR) {
error = ENOTBLK;
goto out;
}
error = 0;
dev_lock();
if (vp->v_rdev == NULL)
error = ENXIO;
else if (vp->v_rdev->si_devsw == NULL)
error = ENXIO;
else if (!(vp->v_rdev->si_devsw->d_flags & D_DISK))
error = ENOTBLK;
dev_unlock();
out:
if (errp != NULL)
*errp = error;
return (error == 0);
}
/*
* Common filesystem object access control check routine. Accepts a
* vnode's type, "mode", uid and gid, requested access mode, credentials,
* and optional call-by-reference privused argument allowing vaccess()
* to indicate to the caller whether privilege was used to satisfy the
* request (obsoleted). Returns 0 on success, or an errno on failure.
*/
int
vaccess(enum vtype type, mode_t file_mode, uid_t file_uid, gid_t file_gid,
accmode_t accmode, struct ucred *cred, int *privused)
{
accmode_t dac_granted;
accmode_t priv_granted;
KASSERT((accmode & ~(VEXEC | VWRITE | VREAD | VADMIN | VAPPEND)) == 0,
("invalid bit in accmode"));
KASSERT((accmode & VAPPEND) == 0 || (accmode & VWRITE),
("VAPPEND without VWRITE"));
/*
* Look for a normal, non-privileged way to access the file/directory
* as requested. If it exists, go with that.
*/
if (privused != NULL)
*privused = 0;
dac_granted = 0;
/* Check the owner. */
if (cred->cr_uid == file_uid) {
dac_granted |= VADMIN;
if (file_mode & S_IXUSR)
dac_granted |= VEXEC;
if (file_mode & S_IRUSR)
dac_granted |= VREAD;
if (file_mode & S_IWUSR)
dac_granted |= (VWRITE | VAPPEND);
if ((accmode & dac_granted) == accmode)
return (0);
goto privcheck;
}
/* Otherwise, check the groups (first match) */
if (groupmember(file_gid, cred)) {
if (file_mode & S_IXGRP)
dac_granted |= VEXEC;
if (file_mode & S_IRGRP)
dac_granted |= VREAD;
if (file_mode & S_IWGRP)
dac_granted |= (VWRITE | VAPPEND);
if ((accmode & dac_granted) == accmode)
return (0);
goto privcheck;
}
/* Otherwise, check everyone else. */
if (file_mode & S_IXOTH)
dac_granted |= VEXEC;
if (file_mode & S_IROTH)
dac_granted |= VREAD;
if (file_mode & S_IWOTH)
dac_granted |= (VWRITE | VAPPEND);
if ((accmode & dac_granted) == accmode)
return (0);
privcheck:
/*
* Build a privilege mask to determine if the set of privileges
* satisfies the requirements when combined with the granted mask
* from above. For each privilege, if the privilege is required,
* bitwise or the request type onto the priv_granted mask.
*/
priv_granted = 0;
if (type == VDIR) {
/*
* For directories, use PRIV_VFS_LOOKUP to satisfy VEXEC
* requests, instead of PRIV_VFS_EXEC.
*/
if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
!priv_check_cred(cred, PRIV_VFS_LOOKUP, 0))
priv_granted |= VEXEC;
} else {
/*
* Ensure that at least one execute bit is on. Otherwise,
* a privileged user will always succeed, and we don't want
* this to happen unless the file really is executable.
*/
if ((accmode & VEXEC) && ((dac_granted & VEXEC) == 0) &&
(file_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0 &&
!priv_check_cred(cred, PRIV_VFS_EXEC, 0))
priv_granted |= VEXEC;
}
if ((accmode & VREAD) && ((dac_granted & VREAD) == 0) &&
!priv_check_cred(cred, PRIV_VFS_READ, 0))
priv_granted |= VREAD;
if ((accmode & VWRITE) && ((dac_granted & VWRITE) == 0) &&
!priv_check_cred(cred, PRIV_VFS_WRITE, 0))
priv_granted |= (VWRITE | VAPPEND);
if ((accmode & VADMIN) && ((dac_granted & VADMIN) == 0) &&
!priv_check_cred(cred, PRIV_VFS_ADMIN, 0))
priv_granted |= VADMIN;
if ((accmode & (priv_granted | dac_granted)) == accmode) {
/* XXX audit: privilege used */
if (privused != NULL)
*privused = 1;
return (0);
}
return ((accmode & VADMIN) ? EPERM : EACCES);
}
/*
* Credential check based on process requesting service, and per-attribute
* permissions.
*/
int
extattr_check_cred(struct vnode *vp, int attrnamespace, struct ucred *cred,
struct thread *td, accmode_t accmode)
{
/*
* Kernel-invoked always succeeds.
*/
if (cred == NOCRED)
return (0);
/*
* Do not allow privileged processes in jail to directly manipulate
* system attributes.
*/
switch (attrnamespace) {
case EXTATTR_NAMESPACE_SYSTEM:
/* Potentially should be: return (EPERM); */
return (priv_check_cred(cred, PRIV_VFS_EXTATTR_SYSTEM, 0));
case EXTATTR_NAMESPACE_USER:
return (VOP_ACCESS(vp, accmode, cred, td));
default:
return (EPERM);
}
}
#ifdef DEBUG_VFS_LOCKS
/*
* This only exists to suppress warnings from unlocked specfs accesses. It is
* no longer ok to have an unlocked VFS.
*/
#define IGNORE_LOCK(vp) (panicstr != NULL || (vp) == NULL || \
(vp)->v_type == VCHR || (vp)->v_type == VBAD)
int vfs_badlock_ddb = 1; /* Drop into debugger on violation. */
SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_ddb, CTLFLAG_RW, &vfs_badlock_ddb, 0,
"Drop into debugger on lock violation");
int vfs_badlock_mutex = 1; /* Check for interlock across VOPs. */
SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_mutex, CTLFLAG_RW, &vfs_badlock_mutex,
0, "Check for interlock across VOPs");
int vfs_badlock_print = 1; /* Print lock violations. */
SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_print, CTLFLAG_RW, &vfs_badlock_print,
0, "Print lock violations");
int vfs_badlock_vnode = 1; /* Print vnode details on lock violations. */
SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_vnode, CTLFLAG_RW, &vfs_badlock_vnode,
0, "Print vnode details on lock violations");
#ifdef KDB
int vfs_badlock_backtrace = 1; /* Print backtrace at lock violations. */
SYSCTL_INT(_debug, OID_AUTO, vfs_badlock_backtrace, CTLFLAG_RW,
&vfs_badlock_backtrace, 0, "Print backtrace at lock violations");
#endif
static void
vfs_badlock(const char *msg, const char *str, struct vnode *vp)
{
#ifdef KDB
if (vfs_badlock_backtrace)
kdb_backtrace();
#endif
if (vfs_badlock_vnode)
vn_printf(vp, "vnode ");
if (vfs_badlock_print)
printf("%s: %p %s\n", str, (void *)vp, msg);
if (vfs_badlock_ddb)
kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
}
void
assert_vi_locked(struct vnode *vp, const char *str)
{
if (vfs_badlock_mutex && !mtx_owned(VI_MTX(vp)))
vfs_badlock("interlock is not locked but should be", str, vp);
}
void
assert_vi_unlocked(struct vnode *vp, const char *str)
{
if (vfs_badlock_mutex && mtx_owned(VI_MTX(vp)))
vfs_badlock("interlock is locked but should not be", str, vp);
}
void
assert_vop_locked(struct vnode *vp, const char *str)
{
int locked;
if (!IGNORE_LOCK(vp)) {
locked = VOP_ISLOCKED(vp);
if (locked == 0 || locked == LK_EXCLOTHER)
vfs_badlock("is not locked but should be", str, vp);
}
}
void
assert_vop_unlocked(struct vnode *vp, const char *str)
{
if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
vfs_badlock("is locked but should not be", str, vp);
}
void
assert_vop_elocked(struct vnode *vp, const char *str)
{
if (!IGNORE_LOCK(vp) && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
vfs_badlock("is not exclusive locked but should be", str, vp);
}
#endif /* DEBUG_VFS_LOCKS */
void
vop_rename_fail(struct vop_rename_args *ap)
{
if (ap->a_tvp != NULL)
vput(ap->a_tvp);
if (ap->a_tdvp == ap->a_tvp)
vrele(ap->a_tdvp);
else
vput(ap->a_tdvp);
vrele(ap->a_fdvp);
vrele(ap->a_fvp);
}
void
vop_rename_pre(void *ap)
{
struct vop_rename_args *a = ap;
#ifdef DEBUG_VFS_LOCKS
if (a->a_tvp)
ASSERT_VI_UNLOCKED(a->a_tvp, "VOP_RENAME");
ASSERT_VI_UNLOCKED(a->a_tdvp, "VOP_RENAME");
ASSERT_VI_UNLOCKED(a->a_fvp, "VOP_RENAME");
ASSERT_VI_UNLOCKED(a->a_fdvp, "VOP_RENAME");
/* Check the source (from). */
if (a->a_tdvp->v_vnlock != a->a_fdvp->v_vnlock &&
(a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fdvp->v_vnlock))
ASSERT_VOP_UNLOCKED(a->a_fdvp, "vop_rename: fdvp locked");
if (a->a_tvp == NULL || a->a_tvp->v_vnlock != a->a_fvp->v_vnlock)
ASSERT_VOP_UNLOCKED(a->a_fvp, "vop_rename: fvp locked");
/* Check the target. */
if (a->a_tvp)
ASSERT_VOP_LOCKED(a->a_tvp, "vop_rename: tvp not locked");
ASSERT_VOP_LOCKED(a->a_tdvp, "vop_rename: tdvp not locked");
#endif
if (a->a_tdvp != a->a_fdvp)
vhold(a->a_fdvp);
if (a->a_tvp != a->a_fvp)
vhold(a->a_fvp);
vhold(a->a_tdvp);
if (a->a_tvp)
vhold(a->a_tvp);
}
#ifdef DEBUG_VFS_LOCKS
void
vop_strategy_pre(void *ap)
{
struct vop_strategy_args *a;
struct buf *bp;
a = ap;
bp = a->a_bp;
/*
* Cluster ops lock their component buffers but not the IO container.
*/
if ((bp->b_flags & B_CLUSTER) != 0)
return;
if (panicstr == NULL && !BUF_ISLOCKED(bp)) {
if (vfs_badlock_print)
printf(
"VOP_STRATEGY: bp is not locked but should be\n");
if (vfs_badlock_ddb)
kdb_enter(KDB_WHY_VFSLOCK, "lock violation");
}
}
void
vop_lock_pre(void *ap)
{
struct vop_lock1_args *a = ap;
if ((a->a_flags & LK_INTERLOCK) == 0)
ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
else
ASSERT_VI_LOCKED(a->a_vp, "VOP_LOCK");
}
void
vop_lock_post(void *ap, int rc)
{
struct vop_lock1_args *a = ap;
ASSERT_VI_UNLOCKED(a->a_vp, "VOP_LOCK");
if (rc == 0 && (a->a_flags & LK_EXCLOTHER) == 0)
ASSERT_VOP_LOCKED(a->a_vp, "VOP_LOCK");
}
void
vop_unlock_pre(void *ap)
{
struct vop_unlock_args *a = ap;
if (a->a_flags & LK_INTERLOCK)
ASSERT_VI_LOCKED(a->a_vp, "VOP_UNLOCK");
ASSERT_VOP_LOCKED(a->a_vp, "VOP_UNLOCK");
}
void
vop_unlock_post(void *ap, int rc)
{
struct vop_unlock_args *a = ap;
if (a->a_flags & LK_INTERLOCK)
ASSERT_VI_UNLOCKED(a->a_vp, "VOP_UNLOCK");
}
#endif
void
vop_create_post(void *ap, int rc)
{
struct vop_create_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
}
void
vop_deleteextattr_post(void *ap, int rc)
{
struct vop_deleteextattr_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
}
void
vop_link_post(void *ap, int rc)
{
struct vop_link_args *a = ap;
if (!rc) {
VFS_KNOTE_LOCKED(a->a_vp, NOTE_LINK);
VFS_KNOTE_LOCKED(a->a_tdvp, NOTE_WRITE);
}
}
void
vop_mkdir_post(void *ap, int rc)
{
struct vop_mkdir_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
}
void
vop_mknod_post(void *ap, int rc)
{
struct vop_mknod_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
}
void
vop_reclaim_post(void *ap, int rc)
{
struct vop_reclaim_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_REVOKE);
}
void
vop_remove_post(void *ap, int rc)
{
struct vop_remove_args *a = ap;
if (!rc) {
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
}
}
void
vop_rename_post(void *ap, int rc)
{
struct vop_rename_args *a = ap;
long hint;
if (!rc) {
hint = NOTE_WRITE;
if (a->a_fdvp == a->a_tdvp) {
if (a->a_tvp != NULL && a->a_tvp->v_type == VDIR)
hint |= NOTE_LINK;
VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
} else {
hint |= NOTE_EXTEND;
if (a->a_fvp->v_type == VDIR)
hint |= NOTE_LINK;
VFS_KNOTE_UNLOCKED(a->a_fdvp, hint);
if (a->a_fvp->v_type == VDIR && a->a_tvp != NULL &&
a->a_tvp->v_type == VDIR)
hint &= ~NOTE_LINK;
VFS_KNOTE_UNLOCKED(a->a_tdvp, hint);
}
VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
if (a->a_tvp)
VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
}
if (a->a_tdvp != a->a_fdvp)
vdrop(a->a_fdvp);
if (a->a_tvp != a->a_fvp)
vdrop(a->a_fvp);
vdrop(a->a_tdvp);
if (a->a_tvp)
vdrop(a->a_tvp);
}
void
vop_rmdir_post(void *ap, int rc)
{
struct vop_rmdir_args *a = ap;
if (!rc) {
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE | NOTE_LINK);
VFS_KNOTE_LOCKED(a->a_vp, NOTE_DELETE);
}
}
void
vop_setattr_post(void *ap, int rc)
{
struct vop_setattr_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
}
void
vop_setextattr_post(void *ap, int rc)
{
struct vop_setextattr_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
}
void
vop_symlink_post(void *ap, int rc)
{
struct vop_symlink_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_dvp, NOTE_WRITE);
}
void
vop_open_post(void *ap, int rc)
{
struct vop_open_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
}
void
vop_close_post(void *ap, int rc)
{
struct vop_close_args *a = ap;
if (!rc && (a->a_cred != NOCRED || /* filter out revokes */
(a->a_vp->v_iflag & VI_DOOMED) == 0)) {
VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
NOTE_CLOSE_WRITE : NOTE_CLOSE);
}
}
void
vop_read_post(void *ap, int rc)
{
struct vop_read_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
}
void
vop_readdir_post(void *ap, int rc)
{
struct vop_readdir_args *a = ap;
if (!rc)
VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
}
static struct knlist fs_knlist;
static void
vfs_event_init(void *arg)
{
knlist_init_mtx(&fs_knlist, NULL);
}
/* XXX - correct order? */
SYSINIT(vfs_knlist, SI_SUB_VFS, SI_ORDER_ANY, vfs_event_init, NULL);
void
vfs_event_signal(fsid_t *fsid, uint32_t event, intptr_t data __unused)
{
KNOTE_UNLOCKED(&fs_knlist, event);
}
static int filt_fsattach(struct knote *kn);
static void filt_fsdetach(struct knote *kn);
static int filt_fsevent(struct knote *kn, long hint);
struct filterops fs_filtops = {
.f_isfd = 0,
.f_attach = filt_fsattach,
.f_detach = filt_fsdetach,
.f_event = filt_fsevent
};
static int
filt_fsattach(struct knote *kn)
{
kn->kn_flags |= EV_CLEAR;
knlist_add(&fs_knlist, kn, 0);
return (0);
}
static void
filt_fsdetach(struct knote *kn)
{
knlist_remove(&fs_knlist, kn, 0);
}
static int
filt_fsevent(struct knote *kn, long hint)
{
kn->kn_fflags |= hint;
return (kn->kn_fflags != 0);
}
static int
sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
{
struct vfsidctl vc;
int error;
struct mount *mp;
error = SYSCTL_IN(req, &vc, sizeof(vc));
if (error)
return (error);
if (vc.vc_vers != VFS_CTL_VERS1)
return (EINVAL);
mp = vfs_getvfs(&vc.vc_fsid);
if (mp == NULL)
return (ENOENT);
/* ensure that a specific sysctl goes to the right filesystem. */
if (strcmp(vc.vc_fstypename, "*") != 0 &&
strcmp(vc.vc_fstypename, mp->mnt_vfc->vfc_name) != 0) {
vfs_rel(mp);
return (EINVAL);
}
VCTLTOREQ(&vc, req);
error = VFS_SYSCTL(mp, vc.vc_op, req);
vfs_rel(mp);
return (error);
}
SYSCTL_PROC(_vfs, OID_AUTO, ctl, CTLTYPE_OPAQUE | CTLFLAG_WR,
NULL, 0, sysctl_vfs_ctl, "",
"Sysctl by fsid");
/*
* Function to initialize a va_filerev field sensibly.
* XXX: Wouldn't a random number make a lot more sense ??
*/
u_quad_t
init_va_filerev(void)
{
struct bintime bt;
getbinuptime(&bt);
return (((u_quad_t)bt.sec << 32LL) | (bt.frac >> 32LL));
}
static int filt_vfsread(struct knote *kn, long hint);
static int filt_vfswrite(struct knote *kn, long hint);
static int filt_vfsvnode(struct knote *kn, long hint);
static void filt_vfsdetach(struct knote *kn);
static struct filterops vfsread_filtops = {
.f_isfd = 1,
.f_detach = filt_vfsdetach,
.f_event = filt_vfsread
};
static struct filterops vfswrite_filtops = {
.f_isfd = 1,
.f_detach = filt_vfsdetach,
.f_event = filt_vfswrite
};
static struct filterops vfsvnode_filtops = {
.f_isfd = 1,
.f_detach = filt_vfsdetach,
.f_event = filt_vfsvnode
};
static void
vfs_knllock(void *arg)
{
struct vnode *vp = arg;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
}
static void
vfs_knlunlock(void *arg)
{
struct vnode *vp = arg;
VOP_UNLOCK(vp, 0);
}
static void
vfs_knl_assert_locked(void *arg)
{
#ifdef DEBUG_VFS_LOCKS
struct vnode *vp = arg;
ASSERT_VOP_LOCKED(vp, "vfs_knl_assert_locked");
#endif
}
static void
vfs_knl_assert_unlocked(void *arg)
{
#ifdef DEBUG_VFS_LOCKS
struct vnode *vp = arg;
ASSERT_VOP_UNLOCKED(vp, "vfs_knl_assert_unlocked");
#endif
}
int
vfs_kqfilter(struct vop_kqfilter_args *ap)
{
struct vnode *vp = ap->a_vp;
struct knote *kn = ap->a_kn;
struct knlist *knl;
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &vfsread_filtops;
break;
case EVFILT_WRITE:
kn->kn_fop = &vfswrite_filtops;
break;
case EVFILT_VNODE:
kn->kn_fop = &vfsvnode_filtops;
break;
default:
return (EINVAL);
}
kn->kn_hook = (caddr_t)vp;
v_addpollinfo(vp);
if (vp->v_pollinfo == NULL)
return (ENOMEM);
knl = &vp->v_pollinfo->vpi_selinfo.si_note;
vhold(vp);
knlist_add(knl, kn, 0);
return (0);
}
/*
* Detach knote from vnode
*/
static void
filt_vfsdetach(struct knote *kn)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
vdrop(vp);
}
/*ARGSUSED*/
static int
filt_vfsread(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
struct vattr va;
int res;
/*
* filesystem is gone, so set the EOF flag and schedule
* the knote for deletion.
*/
if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
VI_LOCK(vp);
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
VI_UNLOCK(vp);
return (1);
}
if (VOP_GETATTR(vp, &va, curthread->td_ucred))
return (0);
VI_LOCK(vp);
kn->kn_data = va.va_size - kn->kn_fp->f_offset;
res = (kn->kn_sfflags & NOTE_FILE_POLL) != 0 || kn->kn_data != 0;
VI_UNLOCK(vp);
return (res);
}
/*ARGSUSED*/
static int
filt_vfswrite(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
VI_LOCK(vp);
/*
* filesystem is gone, so set the EOF flag and schedule
* the knote for deletion.
*/
if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD))
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
kn->kn_data = 0;
VI_UNLOCK(vp);
return (1);
}
static int
filt_vfsvnode(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
int res;
VI_LOCK(vp);
if (kn->kn_sfflags & hint)
kn->kn_fflags |= hint;
if (hint == NOTE_REVOKE || (hint == 0 && vp->v_type == VBAD)) {
kn->kn_flags |= EV_EOF;
VI_UNLOCK(vp);
return (1);
}
res = (kn->kn_fflags != 0);
VI_UNLOCK(vp);
return (res);
}
int
vfs_read_dirent(struct vop_readdir_args *ap, struct dirent *dp, off_t off)
{
int error;
if (dp->d_reclen > ap->a_uio->uio_resid)
return (ENAMETOOLONG);
error = uiomove(dp, dp->d_reclen, ap->a_uio);
if (error) {
if (ap->a_ncookies != NULL) {
if (ap->a_cookies != NULL)
free(ap->a_cookies, M_TEMP);
ap->a_cookies = NULL;
*ap->a_ncookies = 0;
}
return (error);
}
if (ap->a_ncookies == NULL)
return (0);
KASSERT(ap->a_cookies,
("NULL ap->a_cookies value with non-NULL ap->a_ncookies!"));
*ap->a_cookies = realloc(*ap->a_cookies,
(*ap->a_ncookies + 1) * sizeof(u_long), M_TEMP, M_WAITOK | M_ZERO);
(*ap->a_cookies)[*ap->a_ncookies] = off;
*ap->a_ncookies += 1;
return (0);
}
/*
* Mark for update the access time of the file if the filesystem
* supports VOP_MARKATIME. This functionality is used by execve and
* mmap, so we want to avoid the I/O implied by directly setting
* va_atime for the sake of efficiency.
*/
void
vfs_mark_atime(struct vnode *vp, struct ucred *cred)
{
struct mount *mp;
mp = vp->v_mount;
ASSERT_VOP_LOCKED(vp, "vfs_mark_atime");
if (mp != NULL && (mp->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0)
(void)VOP_MARKATIME(vp);
}
/*
* The purpose of this routine is to remove granularity from accmode_t,
* reducing it into standard unix access bits - VEXEC, VREAD, VWRITE,
* VADMIN and VAPPEND.
*
* If it returns 0, the caller is supposed to continue with the usual
* access checks using 'accmode' as modified by this routine. If it
* returns nonzero value, the caller is supposed to return that value
* as errno.
*
* Note that after this routine runs, accmode may be zero.
*/
int
vfs_unixify_accmode(accmode_t *accmode)
{
/*
* There is no way to specify explicit "deny" rule using
* file mode or POSIX.1e ACLs.
*/
if (*accmode & VEXPLICIT_DENY) {
*accmode = 0;
return (0);
}
/*
* None of these can be translated into usual access bits.
* Also, the common case for NFSv4 ACLs is to not contain
* either of these bits. Caller should check for VWRITE
* on the containing directory instead.
*/
if (*accmode & (VDELETE_CHILD | VDELETE))
return (EPERM);
if (*accmode & VADMIN_PERMS) {
*accmode &= ~VADMIN_PERMS;
*accmode |= VADMIN;
}
/*
* There is no way to deny VREAD_ATTRIBUTES, VREAD_ACL
* or VSYNCHRONIZE using file mode or POSIX.1e ACL.
*/
*accmode &= ~(VSTAT_PERMS | VSYNCHRONIZE);
return (0);
}
/*
* These are helper functions for filesystems to traverse all
* their vnodes. See MNT_VNODE_FOREACH_ALL() in sys/mount.h.
*
* This interface replaces MNT_VNODE_FOREACH.
*/
MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
struct vnode *
__mnt_vnode_next_all(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp;
if (should_yield())
kern_yield(PRI_USER);
MNT_ILOCK(mp);
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
while (vp != NULL && (vp->v_type == VMARKER ||
(vp->v_iflag & VI_DOOMED) != 0))
vp = TAILQ_NEXT(vp, v_nmntvnodes);
/* Check if we are done */
if (vp == NULL) {
__mnt_vnode_markerfree_all(mvp, mp);
/* MNT_IUNLOCK(mp); -- done in above function */
mtx_assert(MNT_MTX(mp), MA_NOTOWNED);
return (NULL);
}
TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
VI_LOCK(vp);
MNT_IUNLOCK(mp);
return (vp);
}
struct vnode *
__mnt_vnode_first_all(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp;
*mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
MNT_ILOCK(mp);
MNT_REF(mp);
(*mvp)->v_type = VMARKER;
vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
while (vp != NULL && (vp->v_type == VMARKER ||
(vp->v_iflag & VI_DOOMED) != 0))
vp = TAILQ_NEXT(vp, v_nmntvnodes);
/* Check if we are done */
if (vp == NULL) {
MNT_REL(mp);
MNT_IUNLOCK(mp);
free(*mvp, M_VNODE_MARKER);
*mvp = NULL;
return (NULL);
}
(*mvp)->v_mount = mp;
TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
VI_LOCK(vp);
MNT_IUNLOCK(mp);
return (vp);
}
void
__mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp)
{
if (*mvp == NULL) {
MNT_IUNLOCK(mp);
return;
}
mtx_assert(MNT_MTX(mp), MA_OWNED);
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
MNT_REL(mp);
MNT_IUNLOCK(mp);
free(*mvp, M_VNODE_MARKER);
*mvp = NULL;
}
/*
* These are helper functions for filesystems to traverse their
* active vnodes. See MNT_VNODE_FOREACH_ACTIVE() in sys/mount.h
*/
static void
mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
{
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
MNT_ILOCK(mp);
MNT_REL(mp);
MNT_IUNLOCK(mp);
free(*mvp, M_VNODE_MARKER);
*mvp = NULL;
}
static struct vnode *
mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp, *nvp;
mtx_assert(&mp->mnt_listmtx, MA_OWNED);
KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
restart:
vp = TAILQ_NEXT(*mvp, v_actfreelist);
TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
while (vp != NULL) {
if (vp->v_type == VMARKER) {
vp = TAILQ_NEXT(vp, v_actfreelist);
continue;
}
if (!VI_TRYLOCK(vp)) {
if (mp_ncpus == 1 || should_yield()) {
TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
mtx_unlock(&mp->mnt_listmtx);
pause("vnacti", 1);
mtx_lock(&mp->mnt_listmtx);
goto restart;
}
continue;
}
KASSERT(vp->v_type != VMARKER, ("locked marker %p", vp));
KASSERT(vp->v_mount == mp || vp->v_mount == NULL,
("alien vnode on the active list %p %p", vp, mp));
if (vp->v_mount == mp && (vp->v_iflag & VI_DOOMED) == 0)
break;
nvp = TAILQ_NEXT(vp, v_actfreelist);
VI_UNLOCK(vp);
vp = nvp;
}
/* Check if we are done */
if (vp == NULL) {
mtx_unlock(&mp->mnt_listmtx);
mnt_vnode_markerfree_active(mvp, mp);
return (NULL);
}
TAILQ_INSERT_AFTER(&mp->mnt_activevnodelist, vp, *mvp, v_actfreelist);
mtx_unlock(&mp->mnt_listmtx);
ASSERT_VI_LOCKED(vp, "active iter");
KASSERT((vp->v_iflag & VI_ACTIVE) != 0, ("Non-active vp %p", vp));
return (vp);
}
struct vnode *
__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp)
{
if (should_yield())
kern_yield(PRI_USER);
mtx_lock(&mp->mnt_listmtx);
return (mnt_vnode_next_active(mvp, mp));
}
struct vnode *
__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp)
{
struct vnode *vp;
*mvp = malloc(sizeof(struct vnode), M_VNODE_MARKER, M_WAITOK | M_ZERO);
MNT_ILOCK(mp);
MNT_REF(mp);
MNT_IUNLOCK(mp);
(*mvp)->v_type = VMARKER;
(*mvp)->v_mount = mp;
mtx_lock(&mp->mnt_listmtx);
vp = TAILQ_FIRST(&mp->mnt_activevnodelist);
if (vp == NULL) {
mtx_unlock(&mp->mnt_listmtx);
mnt_vnode_markerfree_active(mvp, mp);
return (NULL);
}
TAILQ_INSERT_BEFORE(vp, *mvp, v_actfreelist);
return (mnt_vnode_next_active(mvp, mp));
}
void
__mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *mp)
{
if (*mvp == NULL)
return;
mtx_lock(&mp->mnt_listmtx);
TAILQ_REMOVE(&mp->mnt_activevnodelist, *mvp, v_actfreelist);
mtx_unlock(&mp->mnt_listmtx);
mnt_vnode_markerfree_active(mvp, mp);
}
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