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freebsd-dev/sys/kern/vfs_mount.c
Warner Losh 685dc743dc sys: Remove $FreeBSD$: one-line .c pattern 
Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/
2023-08-16 11:54:36 -06:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1999-2004 Poul-Henning Kamp
* Copyright (c) 1999 Michael Smith
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/smp.h>
#include <sys/devctl.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/libkern.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/reboot.h>
#include <sys/sbuf.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/taskqueue.h>
#include <sys/vnode.h>
#include <vm/uma.h>
#include <geom/geom.h>
#include <machine/stdarg.h>
#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>
#define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
static int vfs_domount(struct thread *td, const char *fstype, char *fspath,
uint64_t fsflags, bool jail_export,
struct vfsoptlist **optlist);
static void free_mntarg(struct mntarg *ma);
static int usermount = 0;
SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
"Unprivileged users may mount and unmount file systems");
static bool default_autoro = false;
SYSCTL_BOOL(_vfs, OID_AUTO, default_autoro, CTLFLAG_RW, &default_autoro, 0,
"Retry failed r/w mount as r/o if no explicit ro/rw option is specified");
static bool recursive_forced_unmount = false;
SYSCTL_BOOL(_vfs, OID_AUTO, recursive_forced_unmount, CTLFLAG_RW,
&recursive_forced_unmount, 0, "Recursively unmount stacked upper mounts"
" when a file system is forcibly unmounted");
static SYSCTL_NODE(_vfs, OID_AUTO, deferred_unmount,
CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "deferred unmount controls");
static unsigned int deferred_unmount_retry_limit = 10;
SYSCTL_UINT(_vfs_deferred_unmount, OID_AUTO, retry_limit, CTLFLAG_RW,
&deferred_unmount_retry_limit, 0,
"Maximum number of retries for deferred unmount failure");
static int deferred_unmount_retry_delay_hz;
SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, retry_delay_hz, CTLFLAG_RW,
&deferred_unmount_retry_delay_hz, 0,
"Delay in units of [1/kern.hz]s when retrying a failed deferred unmount");
static int deferred_unmount_total_retries = 0;
SYSCTL_INT(_vfs_deferred_unmount, OID_AUTO, total_retries, CTLFLAG_RD,
&deferred_unmount_total_retries, 0,
"Total number of retried deferred unmounts");
MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
MALLOC_DEFINE(M_STATFS, "statfs", "statfs structure");
static uma_zone_t mount_zone;
/* List of mounted filesystems. */
struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
/* For any iteration/modification of mountlist */
struct mtx_padalign __exclusive_cache_line mountlist_mtx;
EVENTHANDLER_LIST_DEFINE(vfs_mounted);
EVENTHANDLER_LIST_DEFINE(vfs_unmounted);
static void vfs_deferred_unmount(void *arg, int pending);
static struct timeout_task deferred_unmount_task;
static struct mtx deferred_unmount_lock;
MTX_SYSINIT(deferred_unmount, &deferred_unmount_lock, "deferred_unmount",
MTX_DEF);
static STAILQ_HEAD(, mount) deferred_unmount_list =
STAILQ_HEAD_INITIALIZER(deferred_unmount_list);
TASKQUEUE_DEFINE_THREAD(deferred_unmount);
static void mount_devctl_event(const char *type, struct mount *mp, bool donew);
/*
* Global opts, taken by all filesystems
*/
static const char *global_opts[] = {
"errmsg",
"fstype",
"fspath",
"ro",
"rw",
"nosuid",
"noexec",
NULL
};
static int
mount_init(void *mem, int size, int flags)
{
struct mount *mp;
mp = (struct mount *)mem;
mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
mtx_init(&mp->mnt_listmtx, "struct mount vlist mtx", NULL, MTX_DEF);
lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
mp->mnt_pcpu = uma_zalloc_pcpu(pcpu_zone_16, M_WAITOK | M_ZERO);
mp->mnt_ref = 0;
mp->mnt_vfs_ops = 1;
mp->mnt_rootvnode = NULL;
return (0);
}
static void
mount_fini(void *mem, int size)
{
struct mount *mp;
mp = (struct mount *)mem;
uma_zfree_pcpu(pcpu_zone_16, mp->mnt_pcpu);
lockdestroy(&mp->mnt_explock);
mtx_destroy(&mp->mnt_listmtx);
mtx_destroy(&mp->mnt_mtx);
}
static void
vfs_mount_init(void *dummy __unused)
{
TIMEOUT_TASK_INIT(taskqueue_deferred_unmount, &deferred_unmount_task,
0, vfs_deferred_unmount, NULL);
deferred_unmount_retry_delay_hz = hz;
mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
NULL, mount_init, mount_fini, UMA_ALIGN_CACHE, UMA_ZONE_NOFREE);
mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF);
}
SYSINIT(vfs_mount, SI_SUB_VFS, SI_ORDER_ANY, vfs_mount_init, NULL);
/*
* ---------------------------------------------------------------------
* Functions for building and sanitizing the mount options
*/
/* Remove one mount option. */
static void
vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
{
TAILQ_REMOVE(opts, opt, link);
free(opt->name, M_MOUNT);
if (opt->value != NULL)
free(opt->value, M_MOUNT);
free(opt, M_MOUNT);
}
/* Release all resources related to the mount options. */
void
vfs_freeopts(struct vfsoptlist *opts)
{
struct vfsopt *opt;
while (!TAILQ_EMPTY(opts)) {
opt = TAILQ_FIRST(opts);
vfs_freeopt(opts, opt);
}
free(opts, M_MOUNT);
}
void
vfs_deleteopt(struct vfsoptlist *opts, const char *name)
{
struct vfsopt *opt, *temp;
if (opts == NULL)
return;
TAILQ_FOREACH_SAFE(opt, opts, link, temp) {
if (strcmp(opt->name, name) == 0)
vfs_freeopt(opts, opt);
}
}
static int
vfs_isopt_ro(const char *opt)
{
if (strcmp(opt, "ro") == 0 || strcmp(opt, "rdonly") == 0 ||
strcmp(opt, "norw") == 0)
return (1);
return (0);
}
static int
vfs_isopt_rw(const char *opt)
{
if (strcmp(opt, "rw") == 0 || strcmp(opt, "noro") == 0)
return (1);
return (0);
}
/*
* Check if options are equal (with or without the "no" prefix).
*/
static int
vfs_equalopts(const char *opt1, const char *opt2)
{
char *p;
/* "opt" vs. "opt" or "noopt" vs. "noopt" */
if (strcmp(opt1, opt2) == 0)
return (1);
/* "noopt" vs. "opt" */
if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
return (1);
/* "opt" vs. "noopt" */
if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
return (1);
while ((p = strchr(opt1, '.')) != NULL &&
!strncmp(opt1, opt2, ++p - opt1)) {
opt2 += p - opt1;
opt1 = p;
/* "foo.noopt" vs. "foo.opt" */
if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
return (1);
/* "foo.opt" vs. "foo.noopt" */
if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
return (1);
}
/* "ro" / "rdonly" / "norw" / "rw" / "noro" */
if ((vfs_isopt_ro(opt1) || vfs_isopt_rw(opt1)) &&
(vfs_isopt_ro(opt2) || vfs_isopt_rw(opt2)))
return (1);
return (0);
}
/*
* If a mount option is specified several times,
* (with or without the "no" prefix) only keep
* the last occurrence of it.
*/
static void
vfs_sanitizeopts(struct vfsoptlist *opts)
{
struct vfsopt *opt, *opt2, *tmp;
TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
opt2 = TAILQ_PREV(opt, vfsoptlist, link);
while (opt2 != NULL) {
if (vfs_equalopts(opt->name, opt2->name)) {
tmp = TAILQ_PREV(opt2, vfsoptlist, link);
vfs_freeopt(opts, opt2);
opt2 = tmp;
} else {
opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
}
}
}
}
/*
* Build a linked list of mount options from a struct uio.
*/
int
vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
{
struct vfsoptlist *opts;
struct vfsopt *opt;
size_t memused, namelen, optlen;
unsigned int i, iovcnt;
int error;
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
TAILQ_INIT(opts);
memused = 0;
iovcnt = auio->uio_iovcnt;
for (i = 0; i < iovcnt; i += 2) {
namelen = auio->uio_iov[i].iov_len;
optlen = auio->uio_iov[i + 1].iov_len;
memused += sizeof(struct vfsopt) + optlen + namelen;
/*
* Avoid consuming too much memory, and attempts to overflow
* memused.
*/
if (memused > VFS_MOUNTARG_SIZE_MAX ||
optlen > VFS_MOUNTARG_SIZE_MAX ||
namelen > VFS_MOUNTARG_SIZE_MAX) {
error = EINVAL;
goto bad;
}
opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
opt->value = NULL;
opt->len = 0;
opt->pos = i / 2;
opt->seen = 0;
/*
* Do this early, so jumps to "bad" will free the current
* option.
*/
TAILQ_INSERT_TAIL(opts, opt, link);
if (auio->uio_segflg == UIO_SYSSPACE) {
bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
} else {
error = copyin(auio->uio_iov[i].iov_base, opt->name,
namelen);
if (error)
goto bad;
}
/* Ensure names are null-terminated strings. */
if (namelen == 0 || opt->name[namelen - 1] != '\0') {
error = EINVAL;
goto bad;
}
if (optlen != 0) {
opt->len = optlen;
opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
if (auio->uio_segflg == UIO_SYSSPACE) {
bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
optlen);
} else {
error = copyin(auio->uio_iov[i + 1].iov_base,
opt->value, optlen);
if (error)
goto bad;
}
}
}
vfs_sanitizeopts(opts);
*options = opts;
return (0);
bad:
vfs_freeopts(opts);
return (error);
}
/*
* Merge the old mount options with the new ones passed
* in the MNT_UPDATE case.
*
* XXX: This function will keep a "nofoo" option in the new
* options. E.g, if the option's canonical name is "foo",
* "nofoo" ends up in the mount point's active options.
*/
static void
vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *oldopts)
{
struct vfsopt *opt, *new;
TAILQ_FOREACH(opt, oldopts, link) {
new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
new->name = strdup(opt->name, M_MOUNT);
if (opt->len != 0) {
new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
bcopy(opt->value, new->value, opt->len);
} else
new->value = NULL;
new->len = opt->len;
new->seen = opt->seen;
TAILQ_INSERT_HEAD(toopts, new, link);
}
vfs_sanitizeopts(toopts);
}
/*
* Mount a filesystem.
*/
#ifndef _SYS_SYSPROTO_H_
struct nmount_args {
struct iovec *iovp;
unsigned int iovcnt;
int flags;
};
#endif
int
sys_nmount(struct thread *td, struct nmount_args *uap)
{
struct uio *auio;
int error;
u_int iovcnt;
uint64_t flags;
/*
* Mount flags are now 64-bits. On 32-bit archtectures only
* 32-bits are passed in, but from here on everything handles
* 64-bit flags correctly.
*/
flags = uap->flags;
AUDIT_ARG_FFLAGS(flags);
CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
uap->iovp, uap->iovcnt, flags);
/*
* Filter out MNT_ROOTFS. We do not want clients of nmount() in
* userspace to set this flag, but we must filter it out if we want
* MNT_UPDATE on the root file system to work.
* MNT_ROOTFS should only be set by the kernel when mounting its
* root file system.
*/
flags &= ~MNT_ROOTFS;
iovcnt = uap->iovcnt;
/*
* Check that we have an even number of iovec's
* and that we have at least two options.
*/
if ((iovcnt & 1) || (iovcnt < 4)) {
CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
uap->iovcnt);
return (EINVAL);
}
error = copyinuio(uap->iovp, iovcnt, &auio);
if (error) {
CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
__func__, error);
return (error);
}
error = vfs_donmount(td, flags, auio);
free(auio, M_IOV);
return (error);
}
/*
* ---------------------------------------------------------------------
* Various utility functions
*/
/*
* Get a reference on a mount point from a vnode.
*
* The vnode is allowed to be passed unlocked and race against dooming. Note in
* such case there are no guarantees the referenced mount point will still be
* associated with it after the function returns.
*/
struct mount *
vfs_ref_from_vp(struct vnode *vp)
{
struct mount *mp;
struct mount_pcpu *mpcpu;
mp = atomic_load_ptr(&vp->v_mount);
if (__predict_false(mp == NULL)) {
return (mp);
}
if (vfs_op_thread_enter(mp, mpcpu)) {
if (__predict_true(mp == vp->v_mount)) {
vfs_mp_count_add_pcpu(mpcpu, ref, 1);
vfs_op_thread_exit(mp, mpcpu);
} else {
vfs_op_thread_exit(mp, mpcpu);
mp = NULL;
}
} else {
MNT_ILOCK(mp);
if (mp == vp->v_mount) {
MNT_REF(mp);
MNT_IUNLOCK(mp);
} else {
MNT_IUNLOCK(mp);
mp = NULL;
}
}
return (mp);
}
void
vfs_ref(struct mount *mp)
{
struct mount_pcpu *mpcpu;
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
if (vfs_op_thread_enter(mp, mpcpu)) {
vfs_mp_count_add_pcpu(mpcpu, ref, 1);
vfs_op_thread_exit(mp, mpcpu);
return;
}
MNT_ILOCK(mp);
MNT_REF(mp);
MNT_IUNLOCK(mp);
}
/*
* Register ump as an upper mount of the mount associated with
* vnode vp. This registration will be tracked through
* mount_upper_node upper, which should be allocated by the
* caller and stored in per-mount data associated with mp.
*
* If successful, this function will return the mount associated
* with vp, and will ensure that it cannot be unmounted until
* ump has been unregistered as one of its upper mounts.
*
* Upon failure this function will return NULL.
*/
struct mount *
vfs_register_upper_from_vp(struct vnode *vp, struct mount *ump,
struct mount_upper_node *upper)
{
struct mount *mp;
mp = atomic_load_ptr(&vp->v_mount);
if (mp == NULL)
return (NULL);
MNT_ILOCK(mp);
if (mp != vp->v_mount ||
((mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_RECURSE)) != 0)) {
MNT_IUNLOCK(mp);
return (NULL);
}
KASSERT(ump != mp, ("upper and lower mounts are identical"));
upper->mp = ump;
MNT_REF(mp);
TAILQ_INSERT_TAIL(&mp->mnt_uppers, upper, mnt_upper_link);
MNT_IUNLOCK(mp);
return (mp);
}
/*
* Register upper mount ump to receive vnode unlink/reclaim
* notifications from lower mount mp. This registration will
* be tracked through mount_upper_node upper, which should be
* allocated by the caller and stored in per-mount data
* associated with mp.
*
* ump must already be registered as an upper mount of mp
* through a call to vfs_register_upper_from_vp().
*/
void
vfs_register_for_notification(struct mount *mp, struct mount *ump,
struct mount_upper_node *upper)
{
upper->mp = ump;
MNT_ILOCK(mp);
TAILQ_INSERT_TAIL(&mp->mnt_notify, upper, mnt_upper_link);
MNT_IUNLOCK(mp);
}
static void
vfs_drain_upper_locked(struct mount *mp)
{
mtx_assert(MNT_MTX(mp), MA_OWNED);
while (mp->mnt_upper_pending != 0) {
mp->mnt_kern_flag |= MNTK_UPPER_WAITER;
msleep(&mp->mnt_uppers, MNT_MTX(mp), 0, "mntupw", 0);
}
}
/*
* Undo a previous call to vfs_register_for_notification().
* The mount represented by upper must be currently registered
* as an upper mount for mp.
*/
void
vfs_unregister_for_notification(struct mount *mp,
struct mount_upper_node *upper)
{
MNT_ILOCK(mp);
vfs_drain_upper_locked(mp);
TAILQ_REMOVE(&mp->mnt_notify, upper, mnt_upper_link);
MNT_IUNLOCK(mp);
}
/*
* Undo a previous call to vfs_register_upper_from_vp().
* This must be done before mp can be unmounted.
*/
void
vfs_unregister_upper(struct mount *mp, struct mount_upper_node *upper)
{
MNT_ILOCK(mp);
KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0,
("registered upper with pending unmount"));
vfs_drain_upper_locked(mp);
TAILQ_REMOVE(&mp->mnt_uppers, upper, mnt_upper_link);
if ((mp->mnt_kern_flag & MNTK_TASKQUEUE_WAITER) != 0 &&
TAILQ_EMPTY(&mp->mnt_uppers)) {
mp->mnt_kern_flag &= ~MNTK_TASKQUEUE_WAITER;
wakeup(&mp->mnt_taskqueue_link);
}
MNT_REL(mp);
MNT_IUNLOCK(mp);
}
void
vfs_rel(struct mount *mp)
{
struct mount_pcpu *mpcpu;
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
if (vfs_op_thread_enter(mp, mpcpu)) {
vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
vfs_op_thread_exit(mp, mpcpu);
return;
}
MNT_ILOCK(mp);
MNT_REL(mp);
MNT_IUNLOCK(mp);
}
/*
* Allocate and initialize the mount point struct.
*/
struct mount *
vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
struct ucred *cred)
{
struct mount *mp;
mp = uma_zalloc(mount_zone, M_WAITOK);
bzero(&mp->mnt_startzero,
__rangeof(struct mount, mnt_startzero, mnt_endzero));
mp->mnt_kern_flag = 0;
mp->mnt_flag = 0;
mp->mnt_rootvnode = NULL;
mp->mnt_vnodecovered = NULL;
mp->mnt_op = NULL;
mp->mnt_vfc = NULL;
TAILQ_INIT(&mp->mnt_nvnodelist);
mp->mnt_nvnodelistsize = 0;
TAILQ_INIT(&mp->mnt_lazyvnodelist);
mp->mnt_lazyvnodelistsize = 0;
MPPASS(mp->mnt_ref == 0 && mp->mnt_lockref == 0 &&
mp->mnt_writeopcount == 0, mp);
MPASSERT(mp->mnt_vfs_ops == 1, mp,
("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops));
(void) vfs_busy(mp, MBF_NOWAIT);
atomic_add_acq_int(&vfsp->vfc_refcount, 1);
mp->mnt_op = vfsp->vfc_vfsops;
mp->mnt_vfc = vfsp;
mp->mnt_stat.f_type = vfsp->vfc_typenum;
mp->mnt_gen++;
strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
mp->mnt_vnodecovered = vp;
mp->mnt_cred = crdup(cred);
mp->mnt_stat.f_owner = cred->cr_uid;
strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
mp->mnt_iosize_max = DFLTPHYS;
#ifdef MAC
mac_mount_init(mp);
mac_mount_create(cred, mp);
#endif
arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
mp->mnt_upper_pending = 0;
TAILQ_INIT(&mp->mnt_uppers);
TAILQ_INIT(&mp->mnt_notify);
mp->mnt_taskqueue_flags = 0;
mp->mnt_unmount_retries = 0;
return (mp);
}
/*
* Destroy the mount struct previously allocated by vfs_mount_alloc().
*/
void
vfs_mount_destroy(struct mount *mp)
{
MPPASS(mp->mnt_vfs_ops != 0, mp);
vfs_assert_mount_counters(mp);
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_REFEXPIRE;
if (mp->mnt_kern_flag & MNTK_MWAIT) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
while (mp->mnt_ref)
msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
KASSERT(mp->mnt_ref == 0,
("%s: invalid refcount in the drain path @ %s:%d", __func__,
__FILE__, __LINE__));
MPPASS(mp->mnt_writeopcount == 0, mp);
MPPASS(mp->mnt_secondary_writes == 0, mp);
atomic_subtract_rel_int(&mp->mnt_vfc->vfc_refcount, 1);
if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
struct vnode *vp;
TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
vn_printf(vp, "dangling vnode ");
panic("unmount: dangling vnode");
}
KASSERT(mp->mnt_upper_pending == 0, ("mnt_upper_pending"));
KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers"));
KASSERT(TAILQ_EMPTY(&mp->mnt_notify), ("mnt_notify"));
MPPASS(mp->mnt_nvnodelistsize == 0, mp);
MPPASS(mp->mnt_lazyvnodelistsize == 0, mp);
MPPASS(mp->mnt_lockref == 0, mp);
MNT_IUNLOCK(mp);
MPASSERT(mp->mnt_vfs_ops == 1, mp,
("vfs_ops should be 1 but %d found", mp->mnt_vfs_ops));
MPASSERT(mp->mnt_rootvnode == NULL, mp,
("mount point still has a root vnode %p", mp->mnt_rootvnode));
if (mp->mnt_vnodecovered != NULL)
vrele(mp->mnt_vnodecovered);
#ifdef MAC
mac_mount_destroy(mp);
#endif
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
if (mp->mnt_exjail != NULL) {
atomic_subtract_int(&mp->mnt_exjail->cr_prison->pr_exportcnt,
1);
crfree(mp->mnt_exjail);
}
if (mp->mnt_export != NULL) {
vfs_free_addrlist(mp->mnt_export);
free(mp->mnt_export, M_MOUNT);
}
crfree(mp->mnt_cred);
uma_zfree(mount_zone, mp);
}
static bool
vfs_should_downgrade_to_ro_mount(uint64_t fsflags, int error)
{
/* This is an upgrade of an exisiting mount. */
if ((fsflags & MNT_UPDATE) != 0)
return (false);
/* This is already an R/O mount. */
if ((fsflags & MNT_RDONLY) != 0)
return (false);
switch (error) {
case ENODEV: /* generic, geom, ... */
case EACCES: /* cam/scsi, ... */
case EROFS: /* md, mmcsd, ... */
/*
* These errors can be returned by the storage layer to signal
* that the media is read-only. No harm in the R/O mount
* attempt if the error was returned for some other reason.
*/
return (true);
default:
return (false);
}
}
int
vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
{
struct vfsoptlist *optlist;
struct vfsopt *opt, *tmp_opt;
char *fstype, *fspath, *errmsg;
int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
bool autoro, has_nonexport, jail_export;
errmsg = fspath = NULL;
errmsg_len = fspathlen = 0;
errmsg_pos = -1;
autoro = default_autoro;
error = vfs_buildopts(fsoptions, &optlist);
if (error)
return (error);
if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
/*
* We need these two options before the others,
* and they are mandatory for any filesystem.
* Ensure they are NUL terminated as well.
*/
fstypelen = 0;
error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
if (error || fstypelen <= 0 || fstype[fstypelen - 1] != '\0') {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fstype", errmsg_len);
goto bail;
}
fspathlen = 0;
error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
if (error || fspathlen <= 0 || fspath[fspathlen - 1] != '\0') {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fspath", errmsg_len);
goto bail;
}
/*
* Check to see that "export" is only used with the "update", "fstype",
* "fspath", "from" and "errmsg" options when in a vnet jail.
* These are the ones used to set/update exports by mountd(8).
* If only the above options are set in a jail that can run mountd(8),
* then the jail_export argument of vfs_domount() will be true.
* When jail_export is true, the vfs_suser() check does not cause
* failure, but limits the update to exports only.
* This allows mountd(8) running within the vnet jail
* to export file systems visible within the jail, but
* mounted outside of the jail.
*/
/*
* We need to see if we have the "update" option
* before we call vfs_domount(), since vfs_domount() has special
* logic based on MNT_UPDATE. This is very important
* when we want to update the root filesystem.
*/
has_nonexport = false;
jail_export = false;
TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
int do_freeopt = 0;
if (jailed(td->td_ucred) &&
strcmp(opt->name, "export") != 0 &&
strcmp(opt->name, "update") != 0 &&
strcmp(opt->name, "fstype") != 0 &&
strcmp(opt->name, "fspath") != 0 &&
strcmp(opt->name, "from") != 0 &&
strcmp(opt->name, "errmsg") != 0)
has_nonexport = true;
if (strcmp(opt->name, "update") == 0) {
fsflags |= MNT_UPDATE;
do_freeopt = 1;
}
else if (strcmp(opt->name, "async") == 0)
fsflags |= MNT_ASYNC;
else if (strcmp(opt->name, "force") == 0) {
fsflags |= MNT_FORCE;
do_freeopt = 1;
}
else if (strcmp(opt->name, "reload") == 0) {
fsflags |= MNT_RELOAD;
do_freeopt = 1;
}
else if (strcmp(opt->name, "multilabel") == 0)
fsflags |= MNT_MULTILABEL;
else if (strcmp(opt->name, "noasync") == 0)
fsflags &= ~MNT_ASYNC;
else if (strcmp(opt->name, "noatime") == 0)
fsflags |= MNT_NOATIME;
else if (strcmp(opt->name, "atime") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoatime", M_MOUNT);
}
else if (strcmp(opt->name, "noclusterr") == 0)
fsflags |= MNT_NOCLUSTERR;
else if (strcmp(opt->name, "clusterr") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoclusterr", M_MOUNT);
}
else if (strcmp(opt->name, "noclusterw") == 0)
fsflags |= MNT_NOCLUSTERW;
else if (strcmp(opt->name, "clusterw") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoclusterw", M_MOUNT);
}
else if (strcmp(opt->name, "noexec") == 0)
fsflags |= MNT_NOEXEC;
else if (strcmp(opt->name, "exec") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonoexec", M_MOUNT);
}
else if (strcmp(opt->name, "nosuid") == 0)
fsflags |= MNT_NOSUID;
else if (strcmp(opt->name, "suid") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonosuid", M_MOUNT);
}
else if (strcmp(opt->name, "nosymfollow") == 0)
fsflags |= MNT_NOSYMFOLLOW;
else if (strcmp(opt->name, "symfollow") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("nonosymfollow", M_MOUNT);
}
else if (strcmp(opt->name, "noro") == 0) {
fsflags &= ~MNT_RDONLY;
autoro = false;
}
else if (strcmp(opt->name, "rw") == 0) {
fsflags &= ~MNT_RDONLY;
autoro = false;
}
else if (strcmp(opt->name, "ro") == 0) {
fsflags |= MNT_RDONLY;
autoro = false;
}
else if (strcmp(opt->name, "rdonly") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("ro", M_MOUNT);
fsflags |= MNT_RDONLY;
autoro = false;
}
else if (strcmp(opt->name, "autoro") == 0) {
do_freeopt = 1;
autoro = true;
}
else if (strcmp(opt->name, "suiddir") == 0)
fsflags |= MNT_SUIDDIR;
else if (strcmp(opt->name, "sync") == 0)
fsflags |= MNT_SYNCHRONOUS;
else if (strcmp(opt->name, "union") == 0)
fsflags |= MNT_UNION;
else if (strcmp(opt->name, "export") == 0) {
fsflags |= MNT_EXPORTED;
jail_export = true;
} else if (strcmp(opt->name, "automounted") == 0) {
fsflags |= MNT_AUTOMOUNTED;
do_freeopt = 1;
} else if (strcmp(opt->name, "nocover") == 0) {
fsflags |= MNT_NOCOVER;
do_freeopt = 1;
} else if (strcmp(opt->name, "cover") == 0) {
fsflags &= ~MNT_NOCOVER;
do_freeopt = 1;
} else if (strcmp(opt->name, "emptydir") == 0) {
fsflags |= MNT_EMPTYDIR;
do_freeopt = 1;
} else if (strcmp(opt->name, "noemptydir") == 0) {
fsflags &= ~MNT_EMPTYDIR;
do_freeopt = 1;
}
if (do_freeopt)
vfs_freeopt(optlist, opt);
}
/*
* Be ultra-paranoid about making sure the type and fspath
* variables will fit in our mp buffers, including the
* terminating NUL.
*/
if (fstypelen > MFSNAMELEN || fspathlen > MNAMELEN) {
error = ENAMETOOLONG;
goto bail;
}
/*
* If has_nonexport is true or the caller is not running within a
* vnet prison that can run mountd(8), set jail_export false.
*/
if (has_nonexport || !jailed(td->td_ucred) ||
!prison_check_nfsd(td->td_ucred))
jail_export = false;
error = vfs_domount(td, fstype, fspath, fsflags, jail_export, &optlist);
if (error == ENOENT) {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fstype", errmsg_len);
goto bail;
}
/*
* See if we can mount in the read-only mode if the error code suggests
* that it could be possible and the mount options allow for that.
* Never try it if "[no]{ro|rw}" has been explicitly requested and not
* overridden by "autoro".
*/
if (autoro && vfs_should_downgrade_to_ro_mount(fsflags, error)) {
printf("%s: R/W mount failed, possibly R/O media,"
" trying R/O mount\n", __func__);
fsflags |= MNT_RDONLY;
error = vfs_domount(td, fstype, fspath, fsflags, jail_export,
&optlist);
}
bail:
/* copyout the errmsg */
if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
&& errmsg_len > 0 && errmsg != NULL) {
if (fsoptions->uio_segflg == UIO_SYSSPACE) {
bcopy(errmsg,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
} else {
copyout(errmsg,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
}
}
if (optlist != NULL)
vfs_freeopts(optlist);
return (error);
}
/*
* Old mount API.
*/
#ifndef _SYS_SYSPROTO_H_
struct mount_args {
char *type;
char *path;
int flags;
caddr_t data;
};
#endif
/* ARGSUSED */
int
sys_mount(struct thread *td, struct mount_args *uap)
{
char *fstype;
struct vfsconf *vfsp = NULL;
struct mntarg *ma = NULL;
uint64_t flags;
int error;
/*
* Mount flags are now 64-bits. On 32-bit architectures only
* 32-bits are passed in, but from here on everything handles
* 64-bit flags correctly.
*/
flags = uap->flags;
AUDIT_ARG_FFLAGS(flags);
/*
* Filter out MNT_ROOTFS. We do not want clients of mount() in
* userspace to set this flag, but we must filter it out if we want
* MNT_UPDATE on the root file system to work.
* MNT_ROOTFS should only be set by the kernel when mounting its
* root file system.
*/
flags &= ~MNT_ROOTFS;
fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
if (error) {
free(fstype, M_TEMP);
return (error);
}
AUDIT_ARG_TEXT(fstype);
vfsp = vfs_byname_kld(fstype, td, &error);
free(fstype, M_TEMP);
if (vfsp == NULL)
return (ENOENT);
if (((vfsp->vfc_flags & VFCF_SBDRY) != 0 &&
vfsp->vfc_vfsops_sd->vfs_cmount == NULL) ||
((vfsp->vfc_flags & VFCF_SBDRY) == 0 &&
vfsp->vfc_vfsops->vfs_cmount == NULL))
return (EOPNOTSUPP);
ma = mount_argsu(ma, "fstype", uap->type, MFSNAMELEN);
ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
ma = mount_argb(ma, flags & MNT_RDONLY, "noro");
ma = mount_argb(ma, !(flags & MNT_NOSUID), "nosuid");
ma = mount_argb(ma, !(flags & MNT_NOEXEC), "noexec");
if ((vfsp->vfc_flags & VFCF_SBDRY) != 0)
return (vfsp->vfc_vfsops_sd->vfs_cmount(ma, uap->data, flags));
return (vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags));
}
/*
* vfs_domount_first(): first file system mount (not update)
*/
static int
vfs_domount_first(
struct thread *td, /* Calling thread. */
struct vfsconf *vfsp, /* File system type. */
char *fspath, /* Mount path. */
struct vnode *vp, /* Vnode to be covered. */
uint64_t fsflags, /* Flags common to all filesystems. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
struct vattr va;
struct mount *mp;
struct vnode *newdp, *rootvp;
int error, error1;
bool unmounted;
ASSERT_VOP_ELOCKED(vp, __func__);
KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
/*
* If the jail of the calling thread lacks permission for this type of
* file system, or is trying to cover its own root, deny immediately.
*/
if (jailed(td->td_ucred) && (!prison_allow(td->td_ucred,
vfsp->vfc_prison_flag) || vp == td->td_ucred->cr_prison->pr_root)) {
vput(vp);
return (EPERM);
}
/*
* If the user is not root, ensure that they own the directory
* onto which we are attempting to mount.
*/
error = VOP_GETATTR(vp, &va, td->td_ucred);
if (error == 0 && va.va_uid != td->td_ucred->cr_uid)
error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN);
if (error == 0)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (vfsp->vfc_flags & VFCF_FILEMOUNT) {
if (error == 0 && vp->v_type != VDIR && vp->v_type != VREG)
error = EINVAL;
/*
* For file mounts, ensure that there is only one hardlink to the file.
*/
if (error == 0 && vp->v_type == VREG && va.va_nlink != 1)
error = EINVAL;
} else {
if (error == 0 && vp->v_type != VDIR)
error = ENOTDIR;
}
if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0)
error = vn_dir_check_empty(vp);
if (error == 0) {
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL)
vp->v_iflag |= VI_MOUNT;
else
error = EBUSY;
VI_UNLOCK(vp);
}
if (error != 0) {
vput(vp);
return (error);
}
vn_seqc_write_begin(vp);
VOP_UNLOCK(vp);
/* Allocate and initialize the filesystem. */
mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
/* XXXMAC: pass to vfs_mount_alloc? */
mp->mnt_optnew = *optlist;
/* Set the mount level flags. */
mp->mnt_flag = (fsflags &
(MNT_UPDATEMASK | MNT_ROOTFS | MNT_RDONLY | MNT_FORCE));
/*
* Mount the filesystem.
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
error1 = 0;
unmounted = true;
if ((error = VFS_MOUNT(mp)) != 0 ||
(error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 ||
(error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) {
rootvp = NULL;
if (error1 != 0) {
MPASS(error == 0);
rootvp = vfs_cache_root_clear(mp);
if (rootvp != NULL) {
vhold(rootvp);
vrele(rootvp);
}
(void)vn_start_write(NULL, &mp, V_WAIT);
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_UNMOUNTF;
MNT_IUNLOCK(mp);
VFS_PURGE(mp);
error = VFS_UNMOUNT(mp, 0);
vn_finished_write(mp);
if (error != 0) {
printf(
"failed post-mount (%d): rollback unmount returned %d\n",
error1, error);
unmounted = false;
}
error = error1;
}
vfs_unbusy(mp);
mp->mnt_vnodecovered = NULL;
if (unmounted) {
/* XXXKIB wait for mnt_lockref drain? */
vfs_mount_destroy(mp);
}
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vdrop(rootvp);
}
vn_seqc_write_end(vp);
vrele(vp);
return (error);
}
vn_seqc_write_begin(newdp);
VOP_UNLOCK(newdp);
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
mp->mnt_opt = mp->mnt_optnew;
*optlist = NULL;
/*
* Prevent external consumers of mount options from reading mnt_optnew.
*/
mp->mnt_optnew = NULL;
MNT_ILOCK(mp);
if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
(mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
else
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
/*
* VIRF_MOUNTPOINT and v_mountedhere need to be set under the
* vp lock to satisfy vfs_lookup() requirements.
*/
VOP_LOCK(vp, LK_EXCLUSIVE | LK_RETRY);
VI_LOCK(vp);
vn_irflag_set_locked(vp, VIRF_MOUNTPOINT);
vp->v_mountedhere = mp;
VI_UNLOCK(vp);
VOP_UNLOCK(vp);
cache_purge(vp);
/*
* We need to lock both vnodes.
*
* Use vn_lock_pair to avoid establishing an ordering between vnodes
* from different filesystems.
*/
vn_lock_pair(vp, false, LK_EXCLUSIVE, newdp, false, LK_EXCLUSIVE);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
/* Place the new filesystem at the end of the mount list. */
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
vfs_event_signal(NULL, VQ_MOUNT, 0);
VOP_UNLOCK(vp);
EVENTHANDLER_DIRECT_INVOKE(vfs_mounted, mp, newdp, td);
VOP_UNLOCK(newdp);
mount_devctl_event("MOUNT", mp, false);
mountcheckdirs(vp, newdp);
vn_seqc_write_end(vp);
vn_seqc_write_end(newdp);
vrele(newdp);
if ((mp->mnt_flag & MNT_RDONLY) == 0)
vfs_allocate_syncvnode(mp);
vfs_op_exit(mp);
vfs_unbusy(mp);
return (0);
}
/*
* vfs_domount_update(): update of mounted file system
*/
static int
vfs_domount_update(
struct thread *td, /* Calling thread. */
struct vnode *vp, /* Mount point vnode. */
uint64_t fsflags, /* Flags common to all filesystems. */
bool jail_export, /* Got export option in vnet prison. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
struct export_args export;
struct o2export_args o2export;
struct vnode *rootvp;
void *bufp;
struct mount *mp;
int error, export_error, i, len;
uint64_t flag;
gid_t *grps;
bool vfs_suser_failed;
ASSERT_VOP_ELOCKED(vp, __func__);
KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here"));
mp = vp->v_mount;
if ((vp->v_vflag & VV_ROOT) == 0) {
if (vfs_copyopt(*optlist, "export", &export, sizeof(export))
== 0)
error = EXDEV;
else
error = EINVAL;
vput(vp);
return (error);
}
/*
* We only allow the filesystem to be reloaded if it
* is currently mounted read-only.
*/
flag = mp->mnt_flag;
if ((fsflags & MNT_RELOAD) != 0 && (flag & MNT_RDONLY) == 0) {
vput(vp);
return (EOPNOTSUPP); /* Needs translation */
}
/*
* Only privileged root, or (if MNT_USER is set) the user that
* did the original mount is permitted to update it.
*/
/*
* For the case of mountd(8) doing exports in a jail, the vfs_suser()
* call does not cause failure. vfs_domount() has already checked
* that "root" is doing this and vfs_suser() will fail when
* the file system has been mounted outside the jail.
* jail_export set true indicates that "export" is not mixed
* with other options that change mount behaviour.
*/
vfs_suser_failed = false;
error = vfs_suser(mp, td);
if (jail_export && error != 0) {
error = 0;
vfs_suser_failed = true;
}
if (error != 0) {
vput(vp);
return (error);
}
if (vfs_busy(mp, MBF_NOWAIT)) {
vput(vp);
return (EBUSY);
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_MOUNT) != 0 || vp->v_mountedhere != NULL) {
VI_UNLOCK(vp);
vfs_unbusy(mp);
vput(vp);
return (EBUSY);
}
vp->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp);
VOP_UNLOCK(vp);
vfs_op_enter(mp);
vn_seqc_write_begin(vp);
rootvp = NULL;
MNT_ILOCK(mp);
if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
MNT_IUNLOCK(mp);
error = EBUSY;
goto end;
}
if (vfs_suser_failed) {
KASSERT((fsflags & (MNT_EXPORTED | MNT_UPDATE)) ==
(MNT_EXPORTED | MNT_UPDATE),
("%s: jailed export did not set expected fsflags",
__func__));
/*
* For this case, only MNT_UPDATE and
* MNT_EXPORTED have been set in fsflags
* by the options. Only set MNT_UPDATE,
* since that is the one that would be set
* when set in fsflags, below.
*/
mp->mnt_flag |= MNT_UPDATE;
} else {
mp->mnt_flag &= ~MNT_UPDATEMASK;
mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
if ((mp->mnt_flag & MNT_ASYNC) == 0)
mp->mnt_kern_flag &= ~MNTK_ASYNC;
}
rootvp = vfs_cache_root_clear(mp);
MNT_IUNLOCK(mp);
mp->mnt_optnew = *optlist;
vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
/*
* Mount the filesystem.
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
/*
* For the case of mountd(8) doing exports from within a vnet jail,
* "from" is typically not set correctly such that VFS_MOUNT() will
* return ENOENT. It is not obvious that VFS_MOUNT() ever needs to be
* called when mountd is doing exports, but this check only applies to
* the specific case where it is running inside a vnet jail, to
* avoid any POLA violation.
*/
error = 0;
if (!jail_export)
error = VFS_MOUNT(mp);
export_error = 0;
/* Process the export option. */
if (error == 0 && vfs_getopt(mp->mnt_optnew, "export", &bufp,
&len) == 0) {
/* Assume that there is only 1 ABI for each length. */
switch (len) {
case (sizeof(struct oexport_args)):
bzero(&o2export, sizeof(o2export));
/* FALLTHROUGH */
case (sizeof(o2export)):
bcopy(bufp, &o2export, len);
export.ex_flags = (uint64_t)o2export.ex_flags;
export.ex_root = o2export.ex_root;
export.ex_uid = o2export.ex_anon.cr_uid;
export.ex_groups = NULL;
export.ex_ngroups = o2export.ex_anon.cr_ngroups;
if (export.ex_ngroups > 0) {
if (export.ex_ngroups <= XU_NGROUPS) {
export.ex_groups = malloc(
export.ex_ngroups * sizeof(gid_t),
M_TEMP, M_WAITOK);
for (i = 0; i < export.ex_ngroups; i++)
export.ex_groups[i] =
o2export.ex_anon.cr_groups[i];
} else
export_error = EINVAL;
} else if (export.ex_ngroups < 0)
export_error = EINVAL;
export.ex_addr = o2export.ex_addr;
export.ex_addrlen = o2export.ex_addrlen;
export.ex_mask = o2export.ex_mask;
export.ex_masklen = o2export.ex_masklen;
export.ex_indexfile = o2export.ex_indexfile;
export.ex_numsecflavors = o2export.ex_numsecflavors;
if (export.ex_numsecflavors < MAXSECFLAVORS) {
for (i = 0; i < export.ex_numsecflavors; i++)
export.ex_secflavors[i] =
o2export.ex_secflavors[i];
} else
export_error = EINVAL;
if (export_error == 0)
export_error = vfs_export(mp, &export, true);
free(export.ex_groups, M_TEMP);
break;
case (sizeof(export)):
bcopy(bufp, &export, len);
grps = NULL;
if (export.ex_ngroups > 0) {
if (export.ex_ngroups <= NGROUPS_MAX) {
grps = malloc(export.ex_ngroups *
sizeof(gid_t), M_TEMP, M_WAITOK);
export_error = copyin(export.ex_groups,
grps, export.ex_ngroups *
sizeof(gid_t));
if (export_error == 0)
export.ex_groups = grps;
} else
export_error = EINVAL;
} else if (export.ex_ngroups == 0)
export.ex_groups = NULL;
else
export_error = EINVAL;
if (export_error == 0)
export_error = vfs_export(mp, &export, true);
free(grps, M_TEMP);
break;
default:
export_error = EINVAL;
break;
}
}
MNT_ILOCK(mp);
if (error == 0) {
mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE |
MNT_SNAPSHOT);
} else {
/*
* If we fail, restore old mount flags. MNT_QUOTA is special,
* because it is not part of MNT_UPDATEMASK, but it could have
* changed in the meantime if quotactl(2) was called.
* All in all we want current value of MNT_QUOTA, not the old
* one.
*/
mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | (flag & ~MNT_QUOTA);
}
if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
(mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
else
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
if (error != 0)
goto end;
mount_devctl_event("REMOUNT", mp, true);
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
mp->mnt_opt = mp->mnt_optnew;
*optlist = NULL;
(void)VFS_STATFS(mp, &mp->mnt_stat);
/*
* Prevent external consumers of mount options from reading
* mnt_optnew.
*/
mp->mnt_optnew = NULL;
if ((mp->mnt_flag & MNT_RDONLY) == 0)
vfs_allocate_syncvnode(mp);
else
vfs_deallocate_syncvnode(mp);
end:
vfs_op_exit(mp);
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vrele(rootvp);
}
vn_seqc_write_end(vp);
vfs_unbusy(mp);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vrele(vp);
return (error != 0 ? error : export_error);
}
/*
* vfs_domount(): actually attempt a filesystem mount.
*/
static int
vfs_domount(
struct thread *td, /* Calling thread. */
const char *fstype, /* Filesystem type. */
char *fspath, /* Mount path. */
uint64_t fsflags, /* Flags common to all filesystems. */
bool jail_export, /* Got export option in vnet prison. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
struct vfsconf *vfsp;
struct nameidata nd;
struct vnode *vp;
char *pathbuf;
int error;
/*
* Be ultra-paranoid about making sure the type and fspath
* variables will fit in our mp buffers, including the
* terminating NUL.
*/
if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
return (ENAMETOOLONG);
if (jail_export) {
error = priv_check(td, PRIV_NFS_DAEMON);
if (error)
return (error);
} else if (jailed(td->td_ucred) || usermount == 0) {
if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
return (error);
}
/*
* Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
*/
if (fsflags & MNT_EXPORTED) {
error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
if (error)
return (error);
}
if (fsflags & MNT_SUIDDIR) {
error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
if (error)
return (error);
}
/*
* Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
*/
if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
fsflags |= MNT_NOSUID | MNT_USER;
}
/* Load KLDs before we lock the covered vnode to avoid reversals. */
vfsp = NULL;
if ((fsflags & MNT_UPDATE) == 0) {
/* Don't try to load KLDs if we're mounting the root. */
if (fsflags & MNT_ROOTFS) {
if ((vfsp = vfs_byname(fstype)) == NULL)
return (ENODEV);
} else {
if ((vfsp = vfs_byname_kld(fstype, td, &error)) == NULL)
return (error);
}
}
/*
* Get vnode to be covered or mount point's vnode in case of MNT_UPDATE.
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1 | WANTPARENT,
UIO_SYSSPACE, fspath);
error = namei(&nd);
if (error != 0)
return (error);
vp = nd.ni_vp;
/*
* Don't allow stacking file mounts to work around problems with the way
* that namei sets nd.ni_dvp to vp_crossmp for these.
*/
if (vp->v_type == VREG)
fsflags |= MNT_NOCOVER;
if ((fsflags & MNT_UPDATE) == 0) {
if ((vp->v_vflag & VV_ROOT) != 0 &&
(fsflags & MNT_NOCOVER) != 0) {
vput(vp);
error = EBUSY;
goto out;
}
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
strcpy(pathbuf, fspath);
/*
* Note: we allow any vnode type here. If the path sanity check
* succeeds, the type will be validated in vfs_domount_first
* above.
*/
if (vp->v_type == VDIR)
error = vn_path_to_global_path(td, vp, pathbuf,
MNAMELEN);
else
error = vn_path_to_global_path_hardlink(td, vp,
nd.ni_dvp, pathbuf, MNAMELEN,
nd.ni_cnd.cn_nameptr, nd.ni_cnd.cn_namelen);
if (error == 0) {
error = vfs_domount_first(td, vfsp, pathbuf, vp,
fsflags, optlist);
}
free(pathbuf, M_TEMP);
} else
error = vfs_domount_update(td, vp, fsflags, jail_export,
optlist);
out:
NDFREE_PNBUF(&nd);
vrele(nd.ni_dvp);
return (error);
}
/*
* Unmount a filesystem.
*
* Note: unmount takes a path to the vnode mounted on as argument, not
* special file (as before).
*/
#ifndef _SYS_SYSPROTO_H_
struct unmount_args {
char *path;
int flags;
};
#endif
/* ARGSUSED */
int
sys_unmount(struct thread *td, struct unmount_args *uap)
{
return (kern_unmount(td, uap->path, uap->flags));
}
int
kern_unmount(struct thread *td, const char *path, int flags)
{
struct nameidata nd;
struct mount *mp;
char *fsidbuf, *pathbuf;
fsid_t fsid;
int error;
AUDIT_ARG_VALUE(flags);
if (jailed(td->td_ucred) || usermount == 0) {
error = priv_check(td, PRIV_VFS_UNMOUNT);
if (error)
return (error);
}
if (flags & MNT_BYFSID) {
fsidbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(path, fsidbuf, MNAMELEN, NULL);
if (error) {
free(fsidbuf, M_TEMP);
return (error);
}
AUDIT_ARG_TEXT(fsidbuf);
/* Decode the filesystem ID. */
if (sscanf(fsidbuf, "FSID:%d:%d", &fsid.val[0], &fsid.val[1]) != 2) {
free(fsidbuf, M_TEMP);
return (EINVAL);
}
mp = vfs_getvfs(&fsid);
free(fsidbuf, M_TEMP);
if (mp == NULL) {
return (ENOENT);
}
} else {
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(path, pathbuf, MNAMELEN, NULL);
if (error) {
free(pathbuf, M_TEMP);
return (error);
}
/*
* Try to find global path for path argument.
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
UIO_SYSSPACE, pathbuf);
if (namei(&nd) == 0) {
NDFREE_PNBUF(&nd);
error = vn_path_to_global_path(td, nd.ni_vp, pathbuf,
MNAMELEN);
if (error == 0)
vput(nd.ni_vp);
}
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) {
vfs_ref(mp);
break;
}
}
mtx_unlock(&mountlist_mtx);
free(pathbuf, M_TEMP);
if (mp == NULL) {
/*
* Previously we returned ENOENT for a nonexistent path and
* EINVAL for a non-mountpoint. We cannot tell these apart
* now, so in the !MNT_BYFSID case return the more likely
* EINVAL for compatibility.
*/
return (EINVAL);
}
}
/*
* Don't allow unmounting the root filesystem.
*/
if (mp->mnt_flag & MNT_ROOTFS) {
vfs_rel(mp);
return (EINVAL);
}
error = dounmount(mp, flags, td);
return (error);
}
/*
* Return error if any of the vnodes, ignoring the root vnode
* and the syncer vnode, have non-zero usecount.
*
* This function is purely advisory - it can return false positives
* and negatives.
*/
static int
vfs_check_usecounts(struct mount *mp)
{
struct vnode *vp, *mvp;
MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
if ((vp->v_vflag & VV_ROOT) == 0 && vp->v_type != VNON &&
vp->v_usecount != 0) {
VI_UNLOCK(vp);
MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
return (EBUSY);
}
VI_UNLOCK(vp);
}
return (0);
}
static void
dounmount_cleanup(struct mount *mp, struct vnode *coveredvp, int mntkflags)
{
mtx_assert(MNT_MTX(mp), MA_OWNED);
mp->mnt_kern_flag &= ~mntkflags;
if ((mp->mnt_kern_flag & MNTK_MWAIT) != 0) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
vfs_op_exit_locked(mp);
MNT_IUNLOCK(mp);
if (coveredvp != NULL) {
VOP_UNLOCK(coveredvp);
vdrop(coveredvp);
}
vn_finished_write(mp);
vfs_rel(mp);
}
/*
* There are various reference counters associated with the mount point.
* Normally it is permitted to modify them without taking the mnt ilock,
* but this behavior can be temporarily disabled if stable value is needed
* or callers are expected to block (e.g. to not allow new users during
* forced unmount).
*/
void
vfs_op_enter(struct mount *mp)
{
struct mount_pcpu *mpcpu;
int cpu;
MNT_ILOCK(mp);
mp->mnt_vfs_ops++;
if (mp->mnt_vfs_ops > 1) {
MNT_IUNLOCK(mp);
return;
}
vfs_op_barrier_wait(mp);
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
mp->mnt_ref += mpcpu->mntp_ref;
mpcpu->mntp_ref = 0;
mp->mnt_lockref += mpcpu->mntp_lockref;
mpcpu->mntp_lockref = 0;
mp->mnt_writeopcount += mpcpu->mntp_writeopcount;
mpcpu->mntp_writeopcount = 0;
}
MPASSERT(mp->mnt_ref > 0 && mp->mnt_lockref >= 0 &&
mp->mnt_writeopcount >= 0, mp,
("invalid count(s): ref %d lockref %d writeopcount %d",
mp->mnt_ref, mp->mnt_lockref, mp->mnt_writeopcount));
MNT_IUNLOCK(mp);
vfs_assert_mount_counters(mp);
}
void
vfs_op_exit_locked(struct mount *mp)
{
mtx_assert(MNT_MTX(mp), MA_OWNED);
MPASSERT(mp->mnt_vfs_ops > 0, mp,
("invalid vfs_ops count %d", mp->mnt_vfs_ops));
MPASSERT(mp->mnt_vfs_ops > 1 ||
(mp->mnt_kern_flag & (MNTK_UNMOUNT | MNTK_SUSPEND)) == 0, mp,
("vfs_ops too low %d in unmount or suspend", mp->mnt_vfs_ops));
mp->mnt_vfs_ops--;
}
void
vfs_op_exit(struct mount *mp)
{
MNT_ILOCK(mp);
vfs_op_exit_locked(mp);
MNT_IUNLOCK(mp);
}
struct vfs_op_barrier_ipi {
struct mount *mp;
struct smp_rendezvous_cpus_retry_arg srcra;
};
static void
vfs_op_action_func(void *arg)
{
struct vfs_op_barrier_ipi *vfsopipi;
struct mount *mp;
vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra);
mp = vfsopipi->mp;
if (!vfs_op_thread_entered(mp))
smp_rendezvous_cpus_done(arg);
}
static void
vfs_op_wait_func(void *arg, int cpu)
{
struct vfs_op_barrier_ipi *vfsopipi;
struct mount *mp;
struct mount_pcpu *mpcpu;
vfsopipi = __containerof(arg, struct vfs_op_barrier_ipi, srcra);
mp = vfsopipi->mp;
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
while (atomic_load_int(&mpcpu->mntp_thread_in_ops))
cpu_spinwait();
}
void
vfs_op_barrier_wait(struct mount *mp)
{
struct vfs_op_barrier_ipi vfsopipi;
vfsopipi.mp = mp;
smp_rendezvous_cpus_retry(all_cpus,
smp_no_rendezvous_barrier,
vfs_op_action_func,
smp_no_rendezvous_barrier,
vfs_op_wait_func,
&vfsopipi.srcra);
}
#ifdef DIAGNOSTIC
void
vfs_assert_mount_counters(struct mount *mp)
{
struct mount_pcpu *mpcpu;
int cpu;
if (mp->mnt_vfs_ops == 0)
return;
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
if (mpcpu->mntp_ref != 0 ||
mpcpu->mntp_lockref != 0 ||
mpcpu->mntp_writeopcount != 0)
vfs_dump_mount_counters(mp);
}
}
void
vfs_dump_mount_counters(struct mount *mp)
{
struct mount_pcpu *mpcpu;
int ref, lockref, writeopcount;
int cpu;
printf("%s: mp %p vfs_ops %d\n", __func__, mp, mp->mnt_vfs_ops);
printf(" ref : ");
ref = mp->mnt_ref;
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
printf("%d ", mpcpu->mntp_ref);
ref += mpcpu->mntp_ref;
}
printf("\n");
printf(" lockref : ");
lockref = mp->mnt_lockref;
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
printf("%d ", mpcpu->mntp_lockref);
lockref += mpcpu->mntp_lockref;
}
printf("\n");
printf("writeopcount: ");
writeopcount = mp->mnt_writeopcount;
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
printf("%d ", mpcpu->mntp_writeopcount);
writeopcount += mpcpu->mntp_writeopcount;
}
printf("\n");
printf("counter struct total\n");
printf("ref %-5d %-5d\n", mp->mnt_ref, ref);
printf("lockref %-5d %-5d\n", mp->mnt_lockref, lockref);
printf("writeopcount %-5d %-5d\n", mp->mnt_writeopcount, writeopcount);
panic("invalid counts on struct mount");
}
#endif
int
vfs_mount_fetch_counter(struct mount *mp, enum mount_counter which)
{
struct mount_pcpu *mpcpu;
int cpu, sum;
switch (which) {
case MNT_COUNT_REF:
sum = mp->mnt_ref;
break;
case MNT_COUNT_LOCKREF:
sum = mp->mnt_lockref;
break;
case MNT_COUNT_WRITEOPCOUNT:
sum = mp->mnt_writeopcount;
break;
}
CPU_FOREACH(cpu) {
mpcpu = vfs_mount_pcpu_remote(mp, cpu);
switch (which) {
case MNT_COUNT_REF:
sum += mpcpu->mntp_ref;
break;
case MNT_COUNT_LOCKREF:
sum += mpcpu->mntp_lockref;
break;
case MNT_COUNT_WRITEOPCOUNT:
sum += mpcpu->mntp_writeopcount;
break;
}
}
return (sum);
}
static bool
deferred_unmount_enqueue(struct mount *mp, uint64_t flags, bool requeue,
int timeout_ticks)
{
bool enqueued;
enqueued = false;
mtx_lock(&deferred_unmount_lock);
if ((mp->mnt_taskqueue_flags & MNT_DEFERRED) == 0 || requeue) {
mp->mnt_taskqueue_flags = flags | MNT_DEFERRED;
STAILQ_INSERT_TAIL(&deferred_unmount_list, mp,
mnt_taskqueue_link);
enqueued = true;
}
mtx_unlock(&deferred_unmount_lock);
if (enqueued) {
taskqueue_enqueue_timeout(taskqueue_deferred_unmount,
&deferred_unmount_task, timeout_ticks);
}
return (enqueued);
}
/*
* Taskqueue handler for processing async/recursive unmounts
*/
static void
vfs_deferred_unmount(void *argi __unused, int pending __unused)
{
STAILQ_HEAD(, mount) local_unmounts;
uint64_t flags;
struct mount *mp, *tmp;
int error;
unsigned int retries;
bool unmounted;
STAILQ_INIT(&local_unmounts);
mtx_lock(&deferred_unmount_lock);
STAILQ_CONCAT(&local_unmounts, &deferred_unmount_list);
mtx_unlock(&deferred_unmount_lock);
STAILQ_FOREACH_SAFE(mp, &local_unmounts, mnt_taskqueue_link, tmp) {
flags = mp->mnt_taskqueue_flags;
KASSERT((flags & MNT_DEFERRED) != 0,
("taskqueue unmount without MNT_DEFERRED"));
error = dounmount(mp, flags, curthread);
if (error != 0) {
MNT_ILOCK(mp);
unmounted = ((mp->mnt_kern_flag & MNTK_REFEXPIRE) != 0);
MNT_IUNLOCK(mp);
/*
* The deferred unmount thread is the only thread that
* modifies the retry counts, so locking/atomics aren't
* needed here.
*/
retries = (mp->mnt_unmount_retries)++;
deferred_unmount_total_retries++;
if (!unmounted && retries < deferred_unmount_retry_limit) {
deferred_unmount_enqueue(mp, flags, true,
-deferred_unmount_retry_delay_hz);
} else {
if (retries >= deferred_unmount_retry_limit) {
printf("giving up on deferred unmount "
"of %s after %d retries, error %d\n",
mp->mnt_stat.f_mntonname, retries, error);
}
vfs_rel(mp);
}
}
}
}
/*
* Do the actual filesystem unmount.
*/
int
dounmount(struct mount *mp, uint64_t flags, struct thread *td)
{
struct mount_upper_node *upper;
struct vnode *coveredvp, *rootvp;
int error;
uint64_t async_flag;
int mnt_gen_r;
unsigned int retries;
KASSERT((flags & MNT_DEFERRED) == 0 ||
(flags & (MNT_RECURSE | MNT_FORCE)) == (MNT_RECURSE | MNT_FORCE),
("MNT_DEFERRED requires MNT_RECURSE | MNT_FORCE"));
/*
* If the caller has explicitly requested the unmount to be handled by
* the taskqueue and we're not already in taskqueue context, queue
* up the unmount request and exit. This is done prior to any
* credential checks; MNT_DEFERRED should be used only for kernel-
* initiated unmounts and will therefore be processed with the
* (kernel) credentials of the taskqueue thread. Still, callers
* should be sure this is the behavior they want.
*/
if ((flags & MNT_DEFERRED) != 0 &&
taskqueue_member(taskqueue_deferred_unmount, curthread) == 0) {
if (!deferred_unmount_enqueue(mp, flags, false, 0))
vfs_rel(mp);
return (EINPROGRESS);
}
/*
* Only privileged root, or (if MNT_USER is set) the user that did the
* original mount is permitted to unmount this filesystem.
* This check should be made prior to queueing up any recursive
* unmounts of upper filesystems. Those unmounts will be executed
* with kernel thread credentials and are expected to succeed, so
* we must at least ensure the originating context has sufficient
* privilege to unmount the base filesystem before proceeding with
* the uppers.
*/
error = vfs_suser(mp, td);
if (error != 0) {
KASSERT((flags & MNT_DEFERRED) == 0,
("taskqueue unmount with insufficient privilege"));
vfs_rel(mp);
return (error);
}
if (recursive_forced_unmount && ((flags & MNT_FORCE) != 0))
flags |= MNT_RECURSE;
if ((flags & MNT_RECURSE) != 0) {
KASSERT((flags & MNT_FORCE) != 0,
("MNT_RECURSE requires MNT_FORCE"));
MNT_ILOCK(mp);
/*
* Set MNTK_RECURSE to prevent new upper mounts from being
* added, and note that an operation on the uppers list is in
* progress. This will ensure that unregistration from the
* uppers list, and therefore any pending unmount of the upper
* FS, can't complete until after we finish walking the list.
*/
mp->mnt_kern_flag |= MNTK_RECURSE;
mp->mnt_upper_pending++;
TAILQ_FOREACH(upper, &mp->mnt_uppers, mnt_upper_link) {
retries = upper->mp->mnt_unmount_retries;
if (retries > deferred_unmount_retry_limit) {
error = EBUSY;
continue;
}
MNT_IUNLOCK(mp);
vfs_ref(upper->mp);
if (!deferred_unmount_enqueue(upper->mp, flags,
false, 0))
vfs_rel(upper->mp);
MNT_ILOCK(mp);
}
mp->mnt_upper_pending--;
if ((mp->mnt_kern_flag & MNTK_UPPER_WAITER) != 0 &&
mp->mnt_upper_pending == 0) {
mp->mnt_kern_flag &= ~MNTK_UPPER_WAITER;
wakeup(&mp->mnt_uppers);
}
/*
* If we're not on the taskqueue, wait until the uppers list
* is drained before proceeding with unmount. Otherwise, if
* we are on the taskqueue and there are still pending uppers,
* just re-enqueue on the end of the taskqueue.
*/
if ((flags & MNT_DEFERRED) == 0) {
while (error == 0 && !TAILQ_EMPTY(&mp->mnt_uppers)) {
mp->mnt_kern_flag |= MNTK_TASKQUEUE_WAITER;
error = msleep(&mp->mnt_taskqueue_link,
MNT_MTX(mp), PCATCH, "umntqw", 0);
}
if (error != 0) {
MNT_REL(mp);
MNT_IUNLOCK(mp);
return (error);
}
} else if (!TAILQ_EMPTY(&mp->mnt_uppers)) {
MNT_IUNLOCK(mp);
if (error == 0)
deferred_unmount_enqueue(mp, flags, true, 0);
return (error);
}
MNT_IUNLOCK(mp);
KASSERT(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers not empty"));
}
/* Allow the taskqueue to safely re-enqueue on failure */
if ((flags & MNT_DEFERRED) != 0)
vfs_ref(mp);
if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
mnt_gen_r = mp->mnt_gen;
VI_LOCK(coveredvp);
vholdl(coveredvp);
vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
/*
* Check for mp being unmounted while waiting for the
* covered vnode lock.
*/
if (coveredvp->v_mountedhere != mp ||
coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
VOP_UNLOCK(coveredvp);
vdrop(coveredvp);
vfs_rel(mp);
return (EBUSY);
}
}
vfs_op_enter(mp);
vn_start_write(NULL, &mp, V_WAIT);
MNT_ILOCK(mp);
if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0 ||
(mp->mnt_flag & MNT_UPDATE) != 0 ||
!TAILQ_EMPTY(&mp->mnt_uppers)) {
dounmount_cleanup(mp, coveredvp, 0);
return (EBUSY);
}
mp->mnt_kern_flag |= MNTK_UNMOUNT;
rootvp = vfs_cache_root_clear(mp);
if (coveredvp != NULL)
vn_seqc_write_begin(coveredvp);
if (flags & MNT_NONBUSY) {
MNT_IUNLOCK(mp);
error = vfs_check_usecounts(mp);
MNT_ILOCK(mp);
if (error != 0) {
vn_seqc_write_end(coveredvp);
dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT);
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vrele(rootvp);
}
return (error);
}
}
/* Allow filesystems to detect that a forced unmount is in progress. */
if (flags & MNT_FORCE) {
mp->mnt_kern_flag |= MNTK_UNMOUNTF;
MNT_IUNLOCK(mp);
/*
* Must be done after setting MNTK_UNMOUNTF and before
* waiting for mnt_lockref to become 0.
*/
VFS_PURGE(mp);
MNT_ILOCK(mp);
}
error = 0;
if (mp->mnt_lockref) {
mp->mnt_kern_flag |= MNTK_DRAINING;
error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
"mount drain", 0);
}
MNT_IUNLOCK(mp);
KASSERT(mp->mnt_lockref == 0,
("%s: invalid lock refcount in the drain path @ %s:%d",
__func__, __FILE__, __LINE__));
KASSERT(error == 0,
("%s: invalid return value for msleep in the drain path @ %s:%d",
__func__, __FILE__, __LINE__));
/*
* We want to keep the vnode around so that we can vn_seqc_write_end
* after we are done with unmount. Downgrade our reference to a mere
* hold count so that we don't interefere with anything.
*/
if (rootvp != NULL) {
vhold(rootvp);
vrele(rootvp);
}
if (mp->mnt_flag & MNT_EXPUBLIC)
vfs_setpublicfs(NULL, NULL, NULL);
vfs_periodic(mp, MNT_WAIT);
MNT_ILOCK(mp);
async_flag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
mp->mnt_kern_flag &= ~MNTK_ASYNC;
MNT_IUNLOCK(mp);
vfs_deallocate_syncvnode(mp);
error = VFS_UNMOUNT(mp, flags);
vn_finished_write(mp);
vfs_rel(mp);
/*
* If we failed to flush the dirty blocks for this mount point,
* undo all the cdir/rdir and rootvnode changes we made above.
* Unless we failed to do so because the device is reporting that
* it doesn't exist anymore.
*/
if (error && error != ENXIO) {
MNT_ILOCK(mp);
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
MNT_IUNLOCK(mp);
vfs_allocate_syncvnode(mp);
MNT_ILOCK(mp);
}
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
mp->mnt_flag |= async_flag;
if ((mp->mnt_flag & MNT_ASYNC) != 0 &&
(mp->mnt_kern_flag & MNTK_NOASYNC) == 0)
mp->mnt_kern_flag |= MNTK_ASYNC;
if (mp->mnt_kern_flag & MNTK_MWAIT) {
mp->mnt_kern_flag &= ~MNTK_MWAIT;
wakeup(mp);
}
vfs_op_exit_locked(mp);
MNT_IUNLOCK(mp);
if (coveredvp) {
vn_seqc_write_end(coveredvp);
VOP_UNLOCK(coveredvp);
vdrop(coveredvp);
}
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vdrop(rootvp);
}
return (error);
}
mtx_lock(&mountlist_mtx);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
EVENTHANDLER_DIRECT_INVOKE(vfs_unmounted, mp, td);
if (coveredvp != NULL) {
VI_LOCK(coveredvp);
vn_irflag_unset_locked(coveredvp, VIRF_MOUNTPOINT);
coveredvp->v_mountedhere = NULL;
vn_seqc_write_end_locked(coveredvp);
VI_UNLOCK(coveredvp);
VOP_UNLOCK(coveredvp);
vdrop(coveredvp);
}
mount_devctl_event("UNMOUNT", mp, false);
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vdrop(rootvp);
}
vfs_event_signal(NULL, VQ_UNMOUNT, 0);
if (rootvnode != NULL && mp == rootvnode->v_mount) {
vrele(rootvnode);
rootvnode = NULL;
}
if (mp == rootdevmp)
rootdevmp = NULL;
if ((flags & MNT_DEFERRED) != 0)
vfs_rel(mp);
vfs_mount_destroy(mp);
return (0);
}
/*
* Report errors during filesystem mounting.
*/
void
vfs_mount_error(struct mount *mp, const char *fmt, ...)
{
struct vfsoptlist *moptlist = mp->mnt_optnew;
va_list ap;
int error, len;
char *errmsg;
error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
if (error || errmsg == NULL || len <= 0)
return;
va_start(ap, fmt);
vsnprintf(errmsg, (size_t)len, fmt, ap);
va_end(ap);
}
void
vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
{
va_list ap;
int error, len;
char *errmsg;
error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
if (error || errmsg == NULL || len <= 0)
return;
va_start(ap, fmt);
vsnprintf(errmsg, (size_t)len, fmt, ap);
va_end(ap);
}
/*
* ---------------------------------------------------------------------
* Functions for querying mount options/arguments from filesystems.
*/
/*
* Check that no unknown options are given
*/
int
vfs_filteropt(struct vfsoptlist *opts, const char **legal)
{
struct vfsopt *opt;
char errmsg[255];
const char **t, *p, *q;
int ret = 0;
TAILQ_FOREACH(opt, opts, link) {
p = opt->name;
q = NULL;
if (p[0] == 'n' && p[1] == 'o')
q = p + 2;
for(t = global_opts; *t != NULL; t++) {
if (strcmp(*t, p) == 0)
break;
if (q != NULL) {
if (strcmp(*t, q) == 0)
break;
}
}
if (*t != NULL)
continue;
for(t = legal; *t != NULL; t++) {
if (strcmp(*t, p) == 0)
break;
if (q != NULL) {
if (strcmp(*t, q) == 0)
break;
}
}
if (*t != NULL)
continue;
snprintf(errmsg, sizeof(errmsg),
"mount option <%s> is unknown", p);
ret = EINVAL;
}
if (ret != 0) {
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(opt->name, "errmsg") == 0) {
strncpy((char *)opt->value, errmsg, opt->len);
break;
}
}
if (opt == NULL)
printf("%s\n", errmsg);
}
return (ret);
}
/*
* Get a mount option by its name.
*
* Return 0 if the option was found, ENOENT otherwise.
* If len is non-NULL it will be filled with the length
* of the option. If buf is non-NULL, it will be filled
* with the address of the option.
*/
int
vfs_getopt(struct vfsoptlist *opts, const char *name, void **buf, int *len)
{
struct vfsopt *opt;
KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (len != NULL)
*len = opt->len;
if (buf != NULL)
*buf = opt->value;
return (0);
}
}
return (ENOENT);
}
int
vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
{
struct vfsopt *opt;
if (opts == NULL)
return (-1);
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
return (opt->pos);
}
}
return (-1);
}
int
vfs_getopt_size(struct vfsoptlist *opts, const char *name, off_t *value)
{
char *opt_value, *vtp;
quad_t iv;
int error, opt_len;
error = vfs_getopt(opts, name, (void **)&opt_value, &opt_len);
if (error != 0)
return (error);
if (opt_len == 0 || opt_value == NULL)
return (EINVAL);
if (opt_value[0] == '\0' || opt_value[opt_len - 1] != '\0')
return (EINVAL);
iv = strtoq(opt_value, &vtp, 0);
if (vtp == opt_value || (vtp[0] != '\0' && vtp[1] != '\0'))
return (EINVAL);
if (iv < 0)
return (EINVAL);
switch (vtp[0]) {
case 't': case 'T':
iv *= 1024;
/* FALLTHROUGH */
case 'g': case 'G':
iv *= 1024;
/* FALLTHROUGH */
case 'm': case 'M':
iv *= 1024;
/* FALLTHROUGH */
case 'k': case 'K':
iv *= 1024;
case '\0':
break;
default:
return (EINVAL);
}
*value = iv;
return (0);
}
char *
vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
{
struct vfsopt *opt;
*error = 0;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->len == 0 ||
((char *)opt->value)[opt->len - 1] != '\0') {
*error = EINVAL;
return (NULL);
}
return (opt->value);
}
*error = ENOENT;
return (NULL);
}
int
vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
uint64_t val)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (w != NULL)
*w |= val;
return (1);
}
}
if (w != NULL)
*w &= ~val;
return (0);
}
int
vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
{
va_list ap;
struct vfsopt *opt;
int ret;
KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->len == 0 || opt->value == NULL)
return (0);
if (((char *)opt->value)[opt->len - 1] != '\0')
return (0);
va_start(ap, fmt);
ret = vsscanf(opt->value, fmt, ap);
va_end(ap);
return (ret);
}
return (0);
}
int
vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = len;
else {
if (opt->len != len)
return (EINVAL);
bcopy(value, opt->value, len);
}
return (0);
}
return (ENOENT);
}
int
vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = len;
else {
if (opt->len < len)
return (EINVAL);
opt->len = len;
bcopy(value, opt->value, len);
}
return (0);
}
return (ENOENT);
}
int
vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
{
struct vfsopt *opt;
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) != 0)
continue;
opt->seen = 1;
if (opt->value == NULL)
opt->len = strlen(value) + 1;
else if (strlcpy(opt->value, value, opt->len) >= opt->len)
return (EINVAL);
return (0);
}
return (ENOENT);
}
/*
* Find and copy a mount option.
*
* The size of the buffer has to be specified
* in len, if it is not the same length as the
* mount option, EINVAL is returned.
* Returns ENOENT if the option is not found.
*/
int
vfs_copyopt(struct vfsoptlist *opts, const char *name, void *dest, int len)
{
struct vfsopt *opt;
KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
TAILQ_FOREACH(opt, opts, link) {
if (strcmp(name, opt->name) == 0) {
opt->seen = 1;
if (len != opt->len)
return (EINVAL);
bcopy(opt->value, dest, opt->len);
return (0);
}
}
return (ENOENT);
}
int
__vfs_statfs(struct mount *mp, struct statfs *sbp)
{
/*
* Filesystems only fill in part of the structure for updates, we
* have to read the entirety first to get all content.
*/
if (sbp != &mp->mnt_stat)
memcpy(sbp, &mp->mnt_stat, sizeof(*sbp));
/*
* Set these in case the underlying filesystem fails to do so.
*/
sbp->f_version = STATFS_VERSION;
sbp->f_namemax = NAME_MAX;
sbp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
sbp->f_nvnodelistsize = mp->mnt_nvnodelistsize;
return (mp->mnt_op->vfs_statfs(mp, sbp));
}
void
vfs_mountedfrom(struct mount *mp, const char *from)
{
bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
strlcpy(mp->mnt_stat.f_mntfromname, from,
sizeof mp->mnt_stat.f_mntfromname);
}
/*
* ---------------------------------------------------------------------
* This is the api for building mount args and mounting filesystems from
* inside the kernel.
*
* The API works by accumulation of individual args. First error is
* latched.
*
* XXX: should be documented in new manpage kernel_mount(9)
*/
/* A memory allocation which must be freed when we are done */
struct mntaarg {
SLIST_ENTRY(mntaarg) next;
};
/* The header for the mount arguments */
struct mntarg {
struct iovec *v;
int len;
int error;
SLIST_HEAD(, mntaarg) list;
};
/*
* Add a boolean argument.
*
* flag is the boolean value.
* name must start with "no".
*/
struct mntarg *
mount_argb(struct mntarg *ma, int flag, const char *name)
{
KASSERT(name[0] == 'n' && name[1] == 'o',
("mount_argb(...,%s): name must start with 'no'", name));
return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
}
/*
* Add an argument printf style
*/
struct mntarg *
mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
{
va_list ap;
struct mntaarg *maa;
struct sbuf *sb;
int len;
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
M_MOUNT, M_WAITOK);
ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
ma->v[ma->len].iov_len = strlen(name) + 1;
ma->len++;
sb = sbuf_new_auto();
va_start(ap, fmt);
sbuf_vprintf(sb, fmt, ap);
va_end(ap);
sbuf_finish(sb);
len = sbuf_len(sb) + 1;
maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INSERT_HEAD(&ma->list, maa, next);
bcopy(sbuf_data(sb), maa + 1, len);
sbuf_delete(sb);
ma->v[ma->len].iov_base = maa + 1;
ma->v[ma->len].iov_len = len;
ma->len++;
return (ma);
}
/*
* Add an argument which is a userland string.
*/
struct mntarg *
mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
{
struct mntaarg *maa;
char *tbuf;
if (val == NULL)
return (ma);
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INSERT_HEAD(&ma->list, maa, next);
tbuf = (void *)(maa + 1);
ma->error = copyinstr(val, tbuf, len, NULL);
return (mount_arg(ma, name, tbuf, -1));
}
/*
* Plain argument.
*
* If length is -1, treat value as a C string.
*/
struct mntarg *
mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
{
if (ma == NULL) {
ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
SLIST_INIT(&ma->list);
}
if (ma->error)
return (ma);
ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
M_MOUNT, M_WAITOK);
ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
ma->v[ma->len].iov_len = strlen(name) + 1;
ma->len++;
ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
if (len < 0)
ma->v[ma->len].iov_len = strlen(val) + 1;
else
ma->v[ma->len].iov_len = len;
ma->len++;
return (ma);
}
/*
* Free a mntarg structure
*/
static void
free_mntarg(struct mntarg *ma)
{
struct mntaarg *maa;
while (!SLIST_EMPTY(&ma->list)) {
maa = SLIST_FIRST(&ma->list);
SLIST_REMOVE_HEAD(&ma->list, next);
free(maa, M_MOUNT);
}
free(ma->v, M_MOUNT);
free(ma, M_MOUNT);
}
/*
* Mount a filesystem
*/
int
kernel_mount(struct mntarg *ma, uint64_t flags)
{
struct uio auio;
int error;
KASSERT(ma != NULL, ("kernel_mount NULL ma"));
KASSERT(ma->error != 0 || ma->v != NULL, ("kernel_mount NULL ma->v"));
KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
error = ma->error;
if (error == 0) {
auio.uio_iov = ma->v;
auio.uio_iovcnt = ma->len;
auio.uio_segflg = UIO_SYSSPACE;
error = vfs_donmount(curthread, flags, &auio);
}
free_mntarg(ma);
return (error);
}
/* Map from mount options to printable formats. */
static struct mntoptnames optnames[] = {
MNTOPT_NAMES
};
#define DEVCTL_LEN 1024
static void
mount_devctl_event(const char *type, struct mount *mp, bool donew)
{
const uint8_t *cp;
struct mntoptnames *fp;
struct sbuf sb;
struct statfs *sfp = &mp->mnt_stat;
char *buf;
buf = malloc(DEVCTL_LEN, M_MOUNT, M_NOWAIT);
if (buf == NULL)
return;
sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN);
sbuf_cpy(&sb, "mount-point=\"");
devctl_safe_quote_sb(&sb, sfp->f_mntonname);
sbuf_cat(&sb, "\" mount-dev=\"");
devctl_safe_quote_sb(&sb, sfp->f_mntfromname);
sbuf_cat(&sb, "\" mount-type=\"");
devctl_safe_quote_sb(&sb, sfp->f_fstypename);
sbuf_cat(&sb, "\" fsid=0x");
cp = (const uint8_t *)&sfp->f_fsid.val[0];
for (int i = 0; i < sizeof(sfp->f_fsid); i++)
sbuf_printf(&sb, "%02x", cp[i]);
sbuf_printf(&sb, " owner=%u flags=\"", sfp->f_owner);
for (fp = optnames; fp->o_opt != 0; fp++) {
if ((mp->mnt_flag & fp->o_opt) != 0) {
sbuf_cat(&sb, fp->o_name);
sbuf_putc(&sb, ';');
}
}
sbuf_putc(&sb, '"');
sbuf_finish(&sb);
/*
* Options are not published because the form of the options depends on
* the file system and may include binary data. In addition, they don't
* necessarily provide enough useful information to be actionable when
* devd processes them.
*/
if (sbuf_error(&sb) == 0)
devctl_notify("VFS", "FS", type, sbuf_data(&sb));
sbuf_delete(&sb);
free(buf, M_MOUNT);
}
/*
* Force remount specified mount point to read-only. The argument
* must be busied to avoid parallel unmount attempts.
*
* Intended use is to prevent further writes if some metadata
* inconsistency is detected. Note that the function still flushes
* all cached metadata and data for the mount point, which might be
* not always suitable.
*/
int
vfs_remount_ro(struct mount *mp)
{
struct vfsoptlist *opts;
struct vfsopt *opt;
struct vnode *vp_covered, *rootvp;
int error;
KASSERT(mp->mnt_lockref > 0,
("vfs_remount_ro: mp %p is not busied", mp));
KASSERT((mp->mnt_kern_flag & MNTK_UNMOUNT) == 0,
("vfs_remount_ro: mp %p is being unmounted (and busy?)", mp));
rootvp = NULL;
vp_covered = mp->mnt_vnodecovered;
error = vget(vp_covered, LK_EXCLUSIVE | LK_NOWAIT);
if (error != 0)
return (error);
VI_LOCK(vp_covered);
if ((vp_covered->v_iflag & VI_MOUNT) != 0) {
VI_UNLOCK(vp_covered);
vput(vp_covered);
return (EBUSY);
}
vp_covered->v_iflag |= VI_MOUNT;
VI_UNLOCK(vp_covered);
vfs_op_enter(mp);
vn_seqc_write_begin(vp_covered);
MNT_ILOCK(mp);
if ((mp->mnt_flag & MNT_RDONLY) != 0) {
MNT_IUNLOCK(mp);
error = EBUSY;
goto out;
}
mp->mnt_flag |= MNT_UPDATE | MNT_FORCE | MNT_RDONLY;
rootvp = vfs_cache_root_clear(mp);
MNT_IUNLOCK(mp);
opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK | M_ZERO);
TAILQ_INIT(opts);
opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK | M_ZERO);
opt->name = strdup("ro", M_MOUNT);
opt->value = NULL;
TAILQ_INSERT_TAIL(opts, opt, link);
vfs_mergeopts(opts, mp->mnt_opt);
mp->mnt_optnew = opts;
error = VFS_MOUNT(mp);
if (error == 0) {
MNT_ILOCK(mp);
mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE);
MNT_IUNLOCK(mp);
vfs_deallocate_syncvnode(mp);
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
mp->mnt_opt = mp->mnt_optnew;
} else {
MNT_ILOCK(mp);
mp->mnt_flag &= ~(MNT_UPDATE | MNT_FORCE | MNT_RDONLY);
MNT_IUNLOCK(mp);
vfs_freeopts(mp->mnt_optnew);
}
mp->mnt_optnew = NULL;
out:
vfs_op_exit(mp);
VI_LOCK(vp_covered);
vp_covered->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp_covered);
vput(vp_covered);
vn_seqc_write_end(vp_covered);
if (rootvp != NULL) {
vn_seqc_write_end(rootvp);
vrele(rootvp);
}
return (error);
}
/*
* Suspend write operations on all local writeable filesystems. Does
* full sync of them in the process.
*
* Iterate over the mount points in reverse order, suspending most
* recently mounted filesystems first. It handles a case where a
* filesystem mounted from a md(4) vnode-backed device should be
* suspended before the filesystem that owns the vnode.
*/
void
suspend_all_fs(void)
{
struct mount *mp;
int error;
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
error = vfs_busy(mp, MBF_MNTLSTLOCK | MBF_NOWAIT);
if (error != 0)
continue;
if ((mp->mnt_flag & (MNT_RDONLY | MNT_LOCAL)) != MNT_LOCAL ||
(mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
mtx_lock(&mountlist_mtx);
vfs_unbusy(mp);
continue;
}
error = vfs_write_suspend(mp, 0);
if (error == 0) {
MNT_ILOCK(mp);
MPASS((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0);
mp->mnt_kern_flag |= MNTK_SUSPEND_ALL;
MNT_IUNLOCK(mp);
mtx_lock(&mountlist_mtx);
} else {
printf("suspend of %s failed, error %d\n",
mp->mnt_stat.f_mntonname, error);
mtx_lock(&mountlist_mtx);
vfs_unbusy(mp);
}
}
mtx_unlock(&mountlist_mtx);
}
void
resume_all_fs(void)
{
struct mount *mp;
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if ((mp->mnt_kern_flag & MNTK_SUSPEND_ALL) == 0)
continue;
mtx_unlock(&mountlist_mtx);
MNT_ILOCK(mp);
MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) != 0);
mp->mnt_kern_flag &= ~MNTK_SUSPEND_ALL;
MNT_IUNLOCK(mp);
vfs_write_resume(mp, 0);
mtx_lock(&mountlist_mtx);
vfs_unbusy(mp);
}
mtx_unlock(&mountlist_mtx);
}
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