| /* |
| * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved. |
| * Copyright (C) 2004-2014 Red Hat, Inc. All rights reserved. |
| * |
| * This file is part of LVM2. |
| * |
| * This copyrighted material is made available to anyone wishing to use, |
| * modify, copy, or redistribute it subject to the terms and conditions |
| * of the GNU Lesser General Public License v.2.1. |
| * |
| * You should have received a copy of the GNU Lesser General Public License |
| * along with this program; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "lib.h" |
| #include "locking.h" |
| #include "locking_types.h" |
| #include "activate.h" |
| #include "config.h" |
| #include "defaults.h" |
| #include "lvm-string.h" |
| #include "lvm-flock.h" |
| #include "lvmcache.h" |
| |
| #include <limits.h> |
| #include <unistd.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <signal.h> |
| |
| static char _lock_dir[PATH_MAX]; |
| |
| static void _fin_file_locking(void) |
| { |
| release_flocks(1); |
| } |
| |
| static void _reset_file_locking(void) |
| { |
| release_flocks(0); |
| } |
| |
| static int _file_lock_resource(struct cmd_context *cmd, const char *resource, |
| uint32_t flags, const struct logical_volume *lv) |
| { |
| char lockfile[PATH_MAX]; |
| unsigned origin_only = (flags & LCK_ORIGIN_ONLY) ? 1 : 0; |
| unsigned revert = (flags & LCK_REVERT) ? 1 : 0; |
| |
| switch (flags & LCK_SCOPE_MASK) { |
| case LCK_ACTIVATION: |
| if (dm_snprintf(lockfile, sizeof(lockfile), |
| "%s/A_%s", _lock_dir, resource + 1) < 0) { |
| log_error("Too long locking filename %s/A_%s.", _lock_dir, resource + 1); |
| return 0; |
| } |
| |
| if (!lock_file(lockfile, flags)) |
| return_0; |
| break; |
| case LCK_VG: |
| if (!strcmp(resource, VG_SYNC_NAMES)) { |
| fs_unlock(); |
| } else if (strcmp(resource, VG_GLOBAL)) |
| /* Skip cache refresh for VG_GLOBAL - the caller handles it */ |
| lvmcache_drop_metadata(resource, 0); |
| |
| /* LCK_CACHE does not require a real lock */ |
| if (flags & LCK_CACHE) |
| break; |
| |
| if (is_orphan_vg(resource) || is_global_vg(resource)) { |
| if (dm_snprintf(lockfile, sizeof(lockfile), |
| "%s/P_%s", _lock_dir, resource + 1) < 0) { |
| log_error("Too long locking filename %s/P_%s.", |
| _lock_dir, resource + 1); |
| return 0; |
| } |
| } else |
| if (dm_snprintf(lockfile, sizeof(lockfile), |
| "%s/V_%s", _lock_dir, resource) < 0) { |
| log_error("Too long locking filename %s/V_%s.", |
| _lock_dir, resource); |
| return 0; |
| } |
| |
| if (!lock_file(lockfile, flags)) |
| return_0; |
| break; |
| case LCK_LV: |
| switch (flags & LCK_TYPE_MASK) { |
| case LCK_UNLOCK: |
| log_very_verbose("Unlocking LV %s%s%s", resource, origin_only ? " without snapshots" : "", revert ? " (reverting)" : ""); |
| if (!lv_resume_if_active(cmd, resource, origin_only, 0, revert, lv_committed(lv))) |
| return 0; |
| break; |
| case LCK_NULL: |
| log_very_verbose("Locking LV %s (NL)", resource); |
| if (!lv_deactivate(cmd, resource, lv_committed(lv))) |
| return 0; |
| break; |
| case LCK_READ: |
| log_very_verbose("Locking LV %s (R)", resource); |
| if (!lv_activate_with_filter(cmd, resource, 0, (lv->status & LV_NOSCAN) ? 1 : 0, |
| (lv->status & LV_TEMPORARY) ? 1 : 0, lv_committed(lv))) |
| return 0; |
| break; |
| case LCK_PREAD: |
| log_very_verbose("Locking LV %s (PR) - ignored", resource); |
| break; |
| case LCK_WRITE: |
| log_very_verbose("Locking LV %s (W)%s", resource, origin_only ? " without snapshots" : ""); |
| if (!lv_suspend_if_active(cmd, resource, origin_only, 0, lv_committed(lv), lv)) |
| return 0; |
| break; |
| case LCK_EXCL: |
| log_very_verbose("Locking LV %s (EX)", resource); |
| if (!lv_activate_with_filter(cmd, resource, 1, (lv->status & LV_NOSCAN) ? 1 : 0, |
| (lv->status & LV_TEMPORARY) ? 1 : 0, lv_committed(lv))) |
| return 0; |
| break; |
| default: |
| break; |
| } |
| break; |
| default: |
| log_error("Unrecognised lock scope: %d", |
| flags & LCK_SCOPE_MASK); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| int init_file_locking(struct locking_type *locking, struct cmd_context *cmd, |
| int suppress_messages) |
| { |
| int r; |
| const char *locking_dir; |
| |
| init_flock(cmd); |
| |
| locking->lock_resource = _file_lock_resource; |
| locking->reset_locking = _reset_file_locking; |
| locking->fin_locking = _fin_file_locking; |
| locking->flags = 0; |
| |
| /* Get lockfile directory from config file */ |
| locking_dir = find_config_tree_str(cmd, global_locking_dir_CFG, NULL); |
| if (!dm_strncpy(_lock_dir, locking_dir, sizeof(_lock_dir))) { |
| log_error("Path for locking_dir %s is invalid.", locking_dir); |
| return 0; |
| } |
| |
| (void) dm_prepare_selinux_context(_lock_dir, S_IFDIR); |
| r = dm_create_dir(_lock_dir); |
| (void) dm_prepare_selinux_context(NULL, 0); |
| |
| if (!r) |
| return 0; |
| |
| /* Trap a read-only file system */ |
| if ((access(_lock_dir, R_OK | W_OK | X_OK) == -1) && (errno == EROFS)) |
| return 0; |
| |
| return 1; |
| } |