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2f304845e2
freebsd-nq/sys/kern/vfs_mount.c
Konstantin Belousov 2f304845e2 Do not allocate struct statfs on kernel stack. 
Right now size of the structure is 472 bytes on amd64, which is
already large and stack allocations are indesirable.  With the ino64
work, MNAMELEN is increased to 1024, which will make it impossible to have
struct statfs on the stack.

Extracted from:	ino64 work by gleb
Discussed with:	mckusick
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-01-05 17:19:26 +00:00

2017 lines
48 KiB
C
Raw Blame History

/*-
* 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/libkern.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/sysent.h>
#include <sys/systm.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, 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");
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 mountlist_mtx;
MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
/*
* 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);
return (0);
}
static void
mount_fini(void *mem, int size)
{
struct mount *mp;
mp = (struct mount *)mem;
lockdestroy(&mp->mnt_explock);
mtx_destroy(&mp->mnt_listmtx);
mtx_destroy(&mp->mnt_mtx);
}
static void
vfs_mount_init(void *dummy __unused)
{
mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), NULL,
NULL, mount_init, mount_fini, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
}
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.
*/
int
sys_nmount(td, uap)
struct thread *td;
struct nmount_args /* {
struct iovec *iovp;
unsigned int iovcnt;
int flags;
} */ *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
*/
void
vfs_ref(struct mount *mp)
{
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
MNT_ILOCK(mp);
MNT_REF(mp);
MNT_IUNLOCK(mp);
}
void
vfs_rel(struct mount *mp)
{
CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
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));
TAILQ_INIT(&mp->mnt_nvnodelist);
mp->mnt_nvnodelistsize = 0;
TAILQ_INIT(&mp->mnt_activevnodelist);
mp->mnt_activevnodelistsize = 0;
TAILQ_INIT(&mp->mnt_tmpfreevnodelist);
mp->mnt_tmpfreevnodelistsize = 0;
mp->mnt_ref = 0;
(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);
TAILQ_INIT(&mp->mnt_uppers);
return (mp);
}
/*
* Destroy the mount struct previously allocated by vfs_mount_alloc().
*/
void
vfs_mount_destroy(struct mount *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__));
if (mp->mnt_writeopcount != 0)
panic("vfs_mount_destroy: nonzero writeopcount");
if (mp->mnt_secondary_writes != 0)
panic("vfs_mount_destroy: nonzero secondary_writes");
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(TAILQ_EMPTY(&mp->mnt_uppers), ("mnt_uppers"));
if (mp->mnt_nvnodelistsize != 0)
panic("vfs_mount_destroy: nonzero nvnodelistsize");
if (mp->mnt_activevnodelistsize != 0)
panic("vfs_mount_destroy: nonzero activevnodelistsize");
if (mp->mnt_tmpfreevnodelistsize != 0)
panic("vfs_mount_destroy: nonzero tmpfreevnodelistsize");
if (mp->mnt_lockref != 0)
panic("vfs_mount_destroy: nonzero lock refcount");
MNT_IUNLOCK(mp);
#ifdef MAC
mac_mount_destroy(mp);
#endif
if (mp->mnt_opt != NULL)
vfs_freeopts(mp->mnt_opt);
crfree(mp->mnt_cred);
uma_zfree(mount_zone, mp);
}
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;
errmsg = fspath = NULL;
errmsg_len = fspathlen = 0;
errmsg_pos = -1;
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 || 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 || fspath[fspathlen - 1] != '\0') {
error = EINVAL;
if (errmsg != NULL)
strncpy(errmsg, "Invalid fspath", errmsg_len);
goto bail;
}
/*
* 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.
*/
TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
if (strcmp(opt->name, "update") == 0) {
fsflags |= MNT_UPDATE;
vfs_freeopt(optlist, opt);
}
else if (strcmp(opt->name, "async") == 0)
fsflags |= MNT_ASYNC;
else if (strcmp(opt->name, "force") == 0) {
fsflags |= MNT_FORCE;
vfs_freeopt(optlist, opt);
}
else if (strcmp(opt->name, "reload") == 0) {
fsflags |= MNT_RELOAD;
vfs_freeopt(optlist, opt);
}
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;
else if (strcmp(opt->name, "rw") == 0)
fsflags &= ~MNT_RDONLY;
else if (strcmp(opt->name, "ro") == 0)
fsflags |= MNT_RDONLY;
else if (strcmp(opt->name, "rdonly") == 0) {
free(opt->name, M_MOUNT);
opt->name = strdup("ro", M_MOUNT);
fsflags |= MNT_RDONLY;
}
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, "automounted") == 0) {
fsflags |= MNT_AUTOMOUNTED;
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;
}
error = vfs_domount(td, fstype, fspath, fsflags, &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(td, uap)
struct thread *td;
struct mount_args /* {
char *type;
char *path;
int flags;
caddr_t data;
} */ *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_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");
error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, flags);
return (error);
}
/*
* 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;
int error;
ASSERT_VOP_ELOCKED(vp, __func__);
KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here"));
/*
* 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, 0);
if (error == 0)
error = vinvalbuf(vp, V_SAVE, 0, 0);
if (error == 0 && vp->v_type != VDIR)
error = ENOTDIR;
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);
}
VOP_UNLOCK(vp, 0);
/* 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));
/*
* Mount the filesystem.
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
error = VFS_MOUNT(mp);
if (error != 0) {
vfs_unbusy(mp);
vfs_mount_destroy(mp);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vrele(vp);
return (error);
}
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;
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);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
cache_purge(vp);
VI_LOCK(vp);
vp->v_iflag &= ~VI_MOUNT;
VI_UNLOCK(vp);
vp->v_mountedhere = mp;
/* 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);
if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
panic("mount: lost mount");
VOP_UNLOCK(vp, 0);
EVENTHANDLER_INVOKE(vfs_mounted, mp, newdp, td);
VOP_UNLOCK(newdp, 0);
mountcheckdirs(vp, newdp);
vrele(newdp);
if ((mp->mnt_flag & MNT_RDONLY) == 0)
vfs_allocate_syncvnode(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. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
struct export_args export;
void *bufp;
struct mount *mp;
int error, export_error, len;
uint64_t flag;
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.
*/
error = vfs_suser(mp, td);
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, 0);
MNT_ILOCK(mp);
if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
MNT_IUNLOCK(mp);
error = EBUSY;
goto end;
}
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;
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.
*/
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(&export, sizeof(export));
/* FALLTHROUGH */
case (sizeof(export)):
bcopy(bufp, &export, len);
export_error = vfs_export(mp, &export);
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;
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_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. */
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 (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)
vfsp = vfs_byname(fstype);
else
vfsp = vfs_byname_kld(fstype, td, &error);
if (vfsp == NULL)
return (ENODEV);
if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
return (EPERM);
}
/*
* Get vnode to be covered or mount point's vnode in case of MNT_UPDATE.
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
UIO_SYSSPACE, fspath, td);
error = namei(&nd);
if (error != 0)
return (error);
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
if ((fsflags & MNT_UPDATE) == 0) {
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
strcpy(pathbuf, fspath);
error = vn_path_to_global_path(td, vp, pathbuf, MNAMELEN);
/* debug.disablefullpath == 1 results in ENODEV */
if (error == 0 || error == ENODEV) {
error = vfs_domount_first(td, vfsp, pathbuf, vp,
fsflags, optlist);
}
free(pathbuf, M_TEMP);
} else
error = vfs_domount_update(td, vp, fsflags, optlist);
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)
{
struct nameidata nd;
struct mount *mp;
char *pathbuf;
int error, id0, id1;
AUDIT_ARG_VALUE(uap->flags);
if (jailed(td->td_ucred) || usermount == 0) {
error = priv_check(td, PRIV_VFS_UNMOUNT);
if (error)
return (error);
}
pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
if (error) {
free(pathbuf, M_TEMP);
return (error);
}
if (uap->flags & MNT_BYFSID) {
AUDIT_ARG_TEXT(pathbuf);
/* Decode the filesystem ID. */
if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
free(pathbuf, M_TEMP);
return (EINVAL);
}
mtx_lock(&mountlist_mtx);
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
if (mp->mnt_stat.f_fsid.val[0] == id0 &&
mp->mnt_stat.f_fsid.val[1] == id1) {
vfs_ref(mp);
break;
}
}
mtx_unlock(&mountlist_mtx);
} else {
/*
* Try to find global path for path argument.
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1,
UIO_SYSSPACE, pathbuf, td);
if (namei(&nd) == 0) {
NDFREE(&nd, NDF_ONLY_PNBUF);
error = vn_path_to_global_path(td, nd.ni_vp, pathbuf,
MNAMELEN);
if (error == 0 || error == ENODEV)
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 ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
}
/*
* Don't allow unmounting the root filesystem.
*/
if (mp->mnt_flag & MNT_ROOTFS) {
vfs_rel(mp);
return (EINVAL);
}
error = dounmount(mp, uap->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);
}
MNT_IUNLOCK(mp);
if (coveredvp != NULL) {
VOP_UNLOCK(coveredvp, 0);
vdrop(coveredvp);
}
vn_finished_write(mp);
}
/*
* Do the actual filesystem unmount.
*/
int
dounmount(struct mount *mp, int flags, struct thread *td)
{
struct vnode *coveredvp, *fsrootvp;
int error;
uint64_t async_flag;
int mnt_gen_r;
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, 0);
vdrop(coveredvp);
vfs_rel(mp);
return (EBUSY);
}
}
/*
* Only privileged root, or (if MNT_USER is set) the user that did the
* original mount is permitted to unmount this filesystem.
*/
error = vfs_suser(mp, td);
if (error != 0) {
if (coveredvp != NULL) {
VOP_UNLOCK(coveredvp, 0);
vdrop(coveredvp);
}
vfs_rel(mp);
return (error);
}
vn_start_write(NULL, &mp, V_WAIT | V_MNTREF);
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 | MNTK_NOINSMNTQ;
if (flags & MNT_NONBUSY) {
MNT_IUNLOCK(mp);
error = vfs_check_usecounts(mp);
MNT_ILOCK(mp);
if (error != 0) {
dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT |
MNTK_NOINSMNTQ);
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__));
if (mp->mnt_flag & MNT_EXPUBLIC)
vfs_setpublicfs(NULL, NULL, NULL);
/*
* From now, we can claim that the use reference on the
* coveredvp is ours, and the ref can be released only by
* successfull unmount by us, or left for later unmount
* attempt. The previously acquired hold reference is no
* longer needed to protect the vnode from reuse.
*/
if (coveredvp != NULL)
vdrop(coveredvp);
vfs_msync(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);
cache_purgevfs(mp, false); /* remove cache entries for this file sys */
vfs_deallocate_syncvnode(mp);
/*
* For forced unmounts, move process cdir/rdir refs on the fs root
* vnode to the covered vnode. For non-forced unmounts we want
* such references to cause an EBUSY error.
*/
if ((flags & MNT_FORCE) &&
VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL &&
(mp->mnt_flag & MNT_IGNORE) == 0)
mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
if (fsrootvp == rootvnode) {
vrele(rootvnode);
rootvnode = NULL;
}
vput(fsrootvp);
}
if ((mp->mnt_flag & MNT_RDONLY) != 0 || (flags & MNT_FORCE) != 0 ||
(error = VFS_SYNC(mp, MNT_WAIT)) == 0)
error = VFS_UNMOUNT(mp, flags);
vn_finished_write(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) {
if ((flags & MNT_FORCE) &&
VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
if (mp->mnt_vnodecovered != NULL &&
(mp->mnt_flag & MNT_IGNORE) == 0)
mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
if (rootvnode == NULL) {
rootvnode = fsrootvp;
vref(rootvnode);
}
vput(fsrootvp);
}
MNT_ILOCK(mp);
mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
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);
}
MNT_IUNLOCK(mp);
if (coveredvp)
VOP_UNLOCK(coveredvp, 0);
return (error);
}
mtx_lock(&mountlist_mtx);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
EVENTHANDLER_INVOKE(vfs_unmounted, mp, td);
if (coveredvp != NULL) {
coveredvp->v_mountedhere = NULL;
vput(coveredvp);
}
vfs_event_signal(NULL, VQ_UNMOUNT, 0);
if (mp == rootdevmp)
rootdevmp = NULL;
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(opts, name, buf, len)
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;
case 'g':
case 'G':
iv *= 1024;
case 'm':
case 'M':
iv *= 1024;
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(opts, name, dest, len)
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)
{
int error;
error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
if (sbp != &mp->mnt_stat)
*sbp = mp->mnt_stat;
return (error);
}
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->v != NULL, ("kernel_mount NULL ma->v"));
KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
auio.uio_iov = ma->v;
auio.uio_iovcnt = ma->len;
auio.uio_segflg = UIO_SYSSPACE;
error = ma->error;
if (!error)
error = vfs_donmount(curthread, flags, &auio);
free_mntarg(ma);
return (error);
}
/*
* A printflike function to mount a filesystem.
*/
int
kernel_vmount(int flags, ...)
{
struct mntarg *ma = NULL;
va_list ap;
const char *cp;
const void *vp;
int error;
va_start(ap, flags);
for (;;) {
cp = va_arg(ap, const char *);
if (cp == NULL)
break;
vp = va_arg(ap, const void *);
ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
}
va_end(ap);
error = kernel_mount(ma, flags);
return (error);
}
void
vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
{
bcopy(oexp, exp, sizeof(*oexp));
exp->ex_numsecflavors = 0;
}
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