diff options
Diffstat (limited to 'freebsd/sys/kern/vfs_mount.c')
| -rw-r--r-- | freebsd/sys/kern/vfs_mount.c | 2052 |
1 files changed, 2052 insertions, 0 deletions
diff --git a/freebsd/sys/kern/vfs_mount.c b/freebsd/sys/kern/vfs_mount.c new file mode 100644 index 00000000..3610763f --- /dev/null +++ b/freebsd/sys/kern/vfs_mount.c @@ -0,0 +1,2052 @@ +/*- + * 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> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/conf.h> +#include <sys/eventhandler.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"); + +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"); + +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); + +EVENTHANDLER_LIST_DEFINE(vfs_mounted); +EVENTHANDLER_LIST_DEFINE(vfs_unmounted); + +/* + * 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. + */ +#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 + */ + +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); + 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); + 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; + + 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; + } + + /* + * 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; + 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) { + vfs_freeopt(optlist, opt); + 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, "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); + + /* + * 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, &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_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, error1; + + 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, deny immediately. + */ + if (jailed(td->td_ucred) && !prison_allow(td->td_ucred, + vfsp->vfc_prison_flag)) { + 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, 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. + */ + error1 = 0; + if ((error = VFS_MOUNT(mp)) != 0 || + (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || + (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { + if (error1 != 0) { + error = error1; + if ((error1 = VFS_UNMOUNT(mp, 0)) != 0) + printf("VFS_UNMOUNT returned %d\n", error1); + } + vfs_unbusy(mp); + mp->mnt_vnodecovered = NULL; + vfs_mount_destroy(mp); + VI_LOCK(vp); + vp->v_iflag &= ~VI_MOUNT; + VI_UNLOCK(vp); + vrele(vp); + return (error); + } + VOP_UNLOCK(newdp, 0); + + 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); + + 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); + vn_lock(newdp, LK_EXCLUSIVE | LK_RETRY); + VOP_UNLOCK(vp, 0); + EVENTHANDLER_DIRECT_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); + } + + /* + * 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; + 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; + if (flags & MNT_NONBUSY) { + MNT_IUNLOCK(mp); + error = vfs_check_usecounts(mp); + MNT_ILOCK(mp); + if (error != 0) { + dounmount_cleanup(mp, coveredvp, MNTK_UNMOUNT); + 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); + 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) { + 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); + } + 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_DIRECT_INVOKE(vfs_unmounted, mp, td); + if (coveredvp != NULL) { + coveredvp->v_mountedhere = NULL; + VOP_UNLOCK(coveredvp, 0); + } + vfs_event_signal(NULL, VQ_UNMOUNT, 0); + if (rootvnode != NULL && mp == rootvnode->v_mount) { + vrele(rootvnode); + rootvnode = NULL; + } + 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(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) +{ + 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; +} |