diff options
Diffstat (limited to 'sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c')
| -rw-r--r-- | sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c b/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c index cdfb432b10ad..7d8768d12dda 100644 --- a/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c +++ b/sys/contrib/openzfs/lib/libzfs/os/linux/libzfs_mount_os.c @@ -409,6 +409,149 @@ do_unmount(zfs_handle_t *zhp, const char *mntpt, int flags) return (rc ? EINVAL : 0); } +#ifdef HAVE_MOUNT_SETATTR +/* + * Build a struct mount_attr for the changed namespace properties. + * Parallel to zfs_add_options() but produces mount_setattr(2) input + * instead of a mount options string. + */ +static void +zfs_add_options_setattr(zfs_handle_t *zhp, struct mount_attr *attr, + uint32_t nspflags) +{ + const char *source; + + if (nspflags & ZFS_MNT_PROP_READONLY) { + if (getprop_uint64(zhp, ZFS_PROP_READONLY, &source)) + attr->attr_set |= MOUNT_ATTR_RDONLY; + else + attr->attr_clr |= MOUNT_ATTR_RDONLY; + } + if (nspflags & ZFS_MNT_PROP_EXEC) { + if (getprop_uint64(zhp, ZFS_PROP_EXEC, &source)) + attr->attr_clr |= MOUNT_ATTR_NOEXEC; + else + attr->attr_set |= MOUNT_ATTR_NOEXEC; + } + if (nspflags & ZFS_MNT_PROP_SETUID) { + if (getprop_uint64(zhp, ZFS_PROP_SETUID, &source)) + attr->attr_clr |= MOUNT_ATTR_NOSUID; + else + attr->attr_set |= MOUNT_ATTR_NOSUID; + } + if (nspflags & ZFS_MNT_PROP_DEVICES) { + if (getprop_uint64(zhp, ZFS_PROP_DEVICES, &source)) + attr->attr_clr |= MOUNT_ATTR_NODEV; + else + attr->attr_set |= MOUNT_ATTR_NODEV; + } + if (nspflags & (ZFS_MNT_PROP_ATIME | ZFS_MNT_PROP_RELATIME)) { + uint64_t atime = getprop_uint64(zhp, ZFS_PROP_ATIME, &source); + uint64_t relatime = getprop_uint64(zhp, + ZFS_PROP_RELATIME, &source); + + attr->attr_clr |= MOUNT_ATTR__ATIME; + if (!atime) + attr->attr_set |= MOUNT_ATTR_NOATIME; + else if (relatime) + attr->attr_set |= MOUNT_ATTR_RELATIME; + else + attr->attr_set |= MOUNT_ATTR_STRICTATIME; + } +} +#endif /* HAVE_MOUNT_SETATTR */ + +/* + * Selectively update per-mount VFS flags for the changed namespace + * properties using mount_setattr(2). Unlike a full remount via mount(2), + * this only modifies the specified flags without resetting others -- + * avoiding clobbering temporary mount flags set by the administrator. + * + * For non-legacy datasets, the single known mountpoint is used. + * For legacy datasets, /proc/mounts is iterated since legacy datasets + * can be mounted at multiple locations. + * + * Falls back to a full remount via zfs_mount() when mount_setattr(2) + * is not available (ENOSYS), except for legacy mounts where a full + * remount would clobber temporary flags. + */ +int +zfs_mount_setattr(zfs_handle_t *zhp, uint32_t nspflags) +{ +#ifdef HAVE_MOUNT_SETATTR + struct mount_attr attr = { 0 }; + char mntpt_prop[ZFS_MAXPROPLEN]; + boolean_t legacy = B_FALSE; + libzfs_handle_t *hdl = zhp->zfs_hdl; + FILE *mnttab; + struct mnttab entry; + int ret = 0; + + if (!zfs_is_mountable_internal(zhp)) + return (0); + + zfs_add_options_setattr(zhp, &attr, nspflags); + if (attr.attr_set == 0 && attr.attr_clr == 0) + return (0); + + if (zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type, + B_FALSE)) { + verify(zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mntpt_prop, + sizeof (mntpt_prop), NULL, NULL, 0, B_FALSE) == 0); + legacy = (strcmp(mntpt_prop, ZFS_MOUNTPOINT_LEGACY) == 0); + } + + if (!legacy) { + char *mntpt = NULL; + + if (!zfs_is_mounted(zhp, &mntpt)) + return (0); + + ret = mount_setattr(AT_FDCWD, mntpt, 0, + &attr, sizeof (attr)); + free(mntpt); + if (ret != 0) { + if (errno == ENOSYS) + return (zfs_mount(zhp, MNTOPT_REMOUNT, 0)); + return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED, + dgettext(TEXT_DOMAIN, "cannot set mount " + "attributes for '%s'"), zhp->zfs_name)); + } + return (0); + } + + /* Legacy: iterate /proc/mounts for all mountpoints. */ + if ((mnttab = fopen(MNTTAB, "re")) == NULL) + return (0); + + while (getmntent(mnttab, &entry) == 0) { + if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0) + continue; + if (strcmp(entry.mnt_special, zhp->zfs_name) != 0) + continue; + + ret = mount_setattr(AT_FDCWD, entry.mnt_mountp, 0, + &attr, sizeof (attr)); + if (ret != 0) { + if (errno == ENOSYS) { + ret = 0; + break; + } + ret = zfs_error_fmt(hdl, EZFS_MOUNTFAILED, + dgettext(TEXT_DOMAIN, "cannot set mount " + "attributes for '%s'"), zhp->zfs_name); + break; + } + } + + (void) fclose(mnttab); + return (ret); +#else + (void) nspflags; + return (zfs_mount(zhp, MNTOPT_REMOUNT, 0)); +#endif +} + int zfs_mount_delegation_check(void) { |