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