external/gpl2/lvm2/dist/lib/locking/locking.h

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
   5  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is part of LVM2.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use,
  10  * modify, copy, or redistribute it subject to the terms and conditions
  11  * of the GNU Lesser General Public License v.2.1.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #ifndef _LVM_LOCKING_H
  19 #define _LVM_LOCKING_H
  20
  21 #include "uuid.h"
  22 #include "config.h"
  23
  24 int init_locking(int type, struct cmd_context *cmd);
  25 void fin_locking(void);
  26 void reset_locking(void);
  27 int vg_write_lock_held(void);
  28 int locking_is_clustered(void);
  29
  30 int remote_lock_held(const char *vol);
  31
  32 /*
  33  * LCK_VG:
  34  *   Lock/unlock on-disk volume group data.
  35  *   Use VG_ORPHANS to lock all orphan PVs.
  36  *   Use VG_GLOBAL as a global lock and to wipe the internal cache.
  37  *   char *vol holds volume group name.
  38  *   Set the LCK_CACHE flag to invalidate 'vol' in the internal cache.
  39  *   If more than one lock needs to be held simultaneously, they must be
  40  *   acquired in alphabetical order of 'vol' (to avoid deadlocks).
  41  *
  42  * LCK_LV:
  43  *   Lock/unlock an individual logical volume
  44  *   char *vol holds lvid
  45  */
  46 int lock_vol(struct cmd_context *cmd, const char *vol, uint32_t flags);
  47
  48 /*
  49  * Internal locking representation.
  50  *   LCK_VG: Uses prefix V_ unless the vol begins with # (i.e. #global or #orphans)
  51  *           or the LCK_CACHE flag is set when it uses the prefix P_.
  52  * If LCK_CACHE is set, we do not take out a real lock.
  53  */
  54
  55 /*
  56  * Does the LVM1 driver have this VG active?
  57  */
  58 int check_lvm1_vg_inactive(struct cmd_context *cmd, const char *vgname);
  59
  60 /*
  61  * Lock type - these numbers are the same as VMS and the IBM DLM
  62  */
  63 #define LCK_TYPE_MASK   0x00000007U
  64
  65 #define LCK_NULL        0x00000000U     /* LCK$_NLMODE */
  66 #define LCK_READ        0x00000001U     /* LCK$_CRMODE */
  67                                         /* LCK$_CWMODE */
  68 #define LCK_PREAD       0x00000003U     /* LCK$_PRMODE */
  69 #define LCK_WRITE       0x00000004U     /* LCK$_PWMODE */
  70 #define LCK_EXCL        0x00000005U     /* LCK$_EXMODE */
  71 #define LCK_UNLOCK      0x00000006U     /* This is ours */
  72
  73 /*
  74  * Lock scope
  75  */
  76 #define LCK_SCOPE_MASK  0x00000008U
  77 #define LCK_VG          0x00000000U
  78 #define LCK_LV          0x00000008U
  79
  80 /*
  81  * Lock bits
  82  */
  83 #define LCK_NONBLOCK    0x00000010U     /* Don't block waiting for lock? */
  84 #define LCK_HOLD        0x00000020U     /* Hold lock when lock_vol returns? */
  85 #define LCK_LOCAL       0x00000040U     /* Don't propagate to other nodes */
  86 #define LCK_CLUSTER_VG  0x00000080U     /* VG is clustered */
  87 #define LCK_CACHE       0x00000100U     /* Operation on cache only using P_ lock */
  88
  89 /*
  90  * Additional lock bits for cluster communication
  91  */
  92 #define LCK_PARTIAL_MODE        0x00000001U     /* Partial activation? */
  93 #define LCK_MIRROR_NOSYNC_MODE  0x00000002U     /* Mirrors don't require sync */
  94 #define LCK_DMEVENTD_MONITOR_MODE       0x00000004U     /* Register with dmeventd */
  95 #define LCK_CONVERT             0x00000008U     /* Convert existing lock */
  96
  97 /*
  98  * Special cases of VG locks.
  99  */
 100 #define VG_ORPHANS      "#orphans"
 101 #define VG_GLOBAL       "#global"
 102
 103 /*
 104  * Common combinations
 105  */
 106 #define LCK_NONE                (LCK_VG | LCK_NULL)
 107
 108 #define LCK_VG_READ             (LCK_VG | LCK_READ | LCK_HOLD)
 109 #define LCK_VG_WRITE            (LCK_VG | LCK_WRITE | LCK_HOLD)
 110 #define LCK_VG_UNLOCK           (LCK_VG | LCK_UNLOCK)
 111 #define LCK_VG_DROP_CACHE       (LCK_VG | LCK_WRITE | LCK_CACHE)
 112 #define LCK_VG_BACKUP           (LCK_VG | LCK_CACHE)
 113
 114 #define LCK_LV_EXCLUSIVE        (LCK_LV | LCK_EXCL)
 115 #define LCK_LV_SUSPEND          (LCK_LV | LCK_WRITE)
 116 #define LCK_LV_RESUME           (LCK_LV | LCK_UNLOCK)
 117 #define LCK_LV_ACTIVATE         (LCK_LV | LCK_READ)
 118 #define LCK_LV_DEACTIVATE       (LCK_LV | LCK_NULL)
 119
 120 #define LCK_MASK (LCK_TYPE_MASK | LCK_SCOPE_MASK)
 121
 122 #define LCK_LV_CLUSTERED(lv)    \
 123         (vg_is_clustered((lv)->vg) ? LCK_CLUSTER_VG : 0)
 124
 125 #define lock_lv_vol(cmd, lv, flags)     \
 126         lock_vol(cmd, (lv)->lvid.s, flags | LCK_LV_CLUSTERED(lv))
 127
 128 #define unlock_vg(cmd, vol)     lock_vol(cmd, vol, LCK_VG_UNLOCK)
 129 #define unlock_and_release_vg(cmd, vg, vol) \
 130         do { \
 131                 unlock_vg(cmd, vol); \
 132                 vg_release(vg); \
 133         } while (0)
 134
 135 #define resume_lv(cmd, lv)      lock_lv_vol(cmd, lv, LCK_LV_RESUME)
 136 #define suspend_lv(cmd, lv)     lock_lv_vol(cmd, lv, LCK_LV_SUSPEND | LCK_HOLD)
 137 #define deactivate_lv(cmd, lv)  lock_lv_vol(cmd, lv, LCK_LV_DEACTIVATE)
 138 #define activate_lv(cmd, lv)    lock_lv_vol(cmd, lv, LCK_LV_ACTIVATE | LCK_HOLD)
 139 #define activate_lv_excl(cmd, lv)       \
 140                                 lock_lv_vol(cmd, lv, LCK_LV_EXCLUSIVE | LCK_HOLD)
 141 #define activate_lv_local(cmd, lv)      \
 142         lock_lv_vol(cmd, lv, LCK_LV_ACTIVATE | LCK_HOLD | LCK_LOCAL)
 143 #define deactivate_lv_local(cmd, lv)    \
 144         lock_lv_vol(cmd, lv, LCK_LV_DEACTIVATE | LCK_LOCAL)
 145 #define drop_cached_metadata(vg)        \
 146         lock_vol((vg)->cmd, (vg)->name, LCK_VG_DROP_CACHE)
 147 #define remote_backup_metadata(vg)      \
 148         lock_vol((vg)->cmd, (vg)->name, LCK_VG_BACKUP)
 149
 150 /* Process list of LVs */
 151 int suspend_lvs(struct cmd_context *cmd, struct dm_list *lvs);
 152 int resume_lvs(struct cmd_context *cmd, struct dm_list *lvs);
 153 int activate_lvs(struct cmd_context *cmd, struct dm_list *lvs, unsigned exclusive);
 154
 155 /* Interrupt handling */
 156 void sigint_clear(void);
 157 void sigint_allow(void);
 158 void sigint_restore(void);
 159 int sigint_caught(void);
 160
 161 #endif