fs/gfs2/lock_dlm.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2009 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/fs.h>
  11 #include <linux/dlm.h>
  12 #include <linux/types.h>
  13 #include <linux/gfs2_ondisk.h>
  14
  15 #include "incore.h"
  16 #include "glock.h"
  17 #include "util.h"
  18
  19
  20 static void gdlm_ast(void *arg)
  21 {
  22         struct gfs2_glock *gl = arg;
  23         unsigned ret = gl->gl_state;
  24         struct gfs2_sbd *sdp = gl->gl_sbd;
  25
  26         BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
  27
  28         if (gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID)
  29                 memset(gl->gl_lvb, 0, GDLM_LVB_SIZE);
  30
  31         switch (gl->gl_lksb.sb_status) {
  32         case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
  33                 if (gl->gl_ops->go_flags & GLOF_ASPACE)
  34                         kmem_cache_free(gfs2_glock_aspace_cachep, gl);
  35                 else
  36                         kmem_cache_free(gfs2_glock_cachep, gl);
  37                 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
  38                         wake_up(&sdp->sd_glock_wait);
  39                 return;
  40         case -DLM_ECANCEL: /* Cancel while getting lock */
  41                 ret |= LM_OUT_CANCELED;
  42                 goto out;
  43         case -EAGAIN: /* Try lock fails */
  44                 goto out;
  45         case -EINVAL: /* Invalid */
  46         case -ENOMEM: /* Out of memory */
  47                 ret |= LM_OUT_ERROR;
  48                 goto out;
  49         case 0: /* Success */
  50                 break;
  51         default: /* Something unexpected */
  52                 BUG();
  53         }
  54
  55         ret = gl->gl_req;
  56         if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
  57                 if (gl->gl_req == LM_ST_SHARED)
  58                         ret = LM_ST_DEFERRED;
  59                 else if (gl->gl_req == LM_ST_DEFERRED)
  60                         ret = LM_ST_SHARED;
  61                 else
  62                         BUG();
  63         }
  64
  65         set_bit(GLF_INITIAL, &gl->gl_flags);
  66         gfs2_glock_complete(gl, ret);
  67         return;
  68 out:
  69         if (!test_bit(GLF_INITIAL, &gl->gl_flags))
  70                 gl->gl_lksb.sb_lkid = 0;
  71         gfs2_glock_complete(gl, ret);
  72 }
  73
  74 static void gdlm_bast(void *arg, int mode)
  75 {
  76         struct gfs2_glock *gl = arg;
  77
  78         switch (mode) {
  79         case DLM_LOCK_EX:
  80                 gfs2_glock_cb(gl, LM_ST_UNLOCKED);
  81                 break;
  82         case DLM_LOCK_CW:
  83                 gfs2_glock_cb(gl, LM_ST_DEFERRED);
  84                 break;
  85         case DLM_LOCK_PR:
  86                 gfs2_glock_cb(gl, LM_ST_SHARED);
  87                 break;
  88         default:
  89                 printk(KERN_ERR "unknown bast mode %d", mode);
  90                 BUG();
  91         }
  92 }
  93
  94 /* convert gfs lock-state to dlm lock-mode */
  95
  96 static int make_mode(const unsigned int lmstate)
  97 {
  98         switch (lmstate) {
  99         case LM_ST_UNLOCKED:
 100                 return DLM_LOCK_NL;
 101         case LM_ST_EXCLUSIVE:
 102                 return DLM_LOCK_EX;
 103         case LM_ST_DEFERRED:
 104                 return DLM_LOCK_CW;
 105         case LM_ST_SHARED:
 106                 return DLM_LOCK_PR;
 107         }
 108         printk(KERN_ERR "unknown LM state %d", lmstate);
 109         BUG();
 110         return -1;
 111 }
 112
 113 static u32 make_flags(const u32 lkid, const unsigned int gfs_flags,
 114                       const int req)
 115 {
 116         u32 lkf = 0;
 117
 118         if (gfs_flags & LM_FLAG_TRY)
 119                 lkf |= DLM_LKF_NOQUEUE;
 120
 121         if (gfs_flags & LM_FLAG_TRY_1CB) {
 122                 lkf |= DLM_LKF_NOQUEUE;
 123                 lkf |= DLM_LKF_NOQUEUEBAST;
 124         }
 125
 126         if (gfs_flags & LM_FLAG_PRIORITY) {
 127                 lkf |= DLM_LKF_NOORDER;
 128                 lkf |= DLM_LKF_HEADQUE;
 129         }
 130
 131         if (gfs_flags & LM_FLAG_ANY) {
 132                 if (req == DLM_LOCK_PR)
 133                         lkf |= DLM_LKF_ALTCW;
 134                 else if (req == DLM_LOCK_CW)
 135                         lkf |= DLM_LKF_ALTPR;
 136                 else
 137                         BUG();
 138         }
 139
 140         if (lkid != 0)
 141                 lkf |= DLM_LKF_CONVERT;
 142
 143         lkf |= DLM_LKF_VALBLK;
 144
 145         return lkf;
 146 }
 147
 148 static unsigned int gdlm_lock(struct gfs2_glock *gl,
 149                               unsigned int req_state, unsigned int flags)
 150 {
 151         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
 152         int error;
 153         int req;
 154         u32 lkf;
 155
 156         gl->gl_req = req_state;
 157         req = make_mode(req_state);
 158         lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req);
 159
 160         /*
 161          * Submit the actual lock request.
 162          */
 163
 164         error = dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, gl->gl_strname,
 165                          GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
 166         if (error == -EAGAIN)
 167                 return 0;
 168         if (error)
 169                 return LM_OUT_ERROR;
 170         return LM_OUT_ASYNC;
 171 }
 172
 173 static void gdlm_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl)
 174 {
 175         struct gfs2_sbd *sdp = gl->gl_sbd;
 176         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 177         int error;
 178
 179         if (gl->gl_lksb.sb_lkid == 0) {
 180                 kmem_cache_free(cachep, gl);
 181                 if (atomic_dec_and_test(&sdp->sd_glock_disposal))
 182                         wake_up(&sdp->sd_glock_wait);
 183                 return;
 184         }
 185
 186         error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
 187                            NULL, gl);
 188         if (error) {
 189                 printk(KERN_ERR "gdlm_unlock %x,%llx err=%d\n",
 190                        gl->gl_name.ln_type,
 191                        (unsigned long long)gl->gl_name.ln_number, error);
 192                 return;
 193         }
 194 }
 195
 196 static void gdlm_cancel(struct gfs2_glock *gl)
 197 {
 198         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
 199         dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
 200 }
 201
 202 static int gdlm_mount(struct gfs2_sbd *sdp, const char *fsname)
 203 {
 204         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 205         int error;
 206
 207         if (fsname == NULL) {
 208                 fs_info(sdp, "no fsname found\n");
 209                 return -EINVAL;
 210         }
 211
 212         error = dlm_new_lockspace(fsname, strlen(fsname), &ls->ls_dlm,
 213                                   DLM_LSFL_FS | DLM_LSFL_NEWEXCL |
 214                                   (ls->ls_nodir ? DLM_LSFL_NODIR : 0),
 215                                   GDLM_LVB_SIZE);
 216         if (error)
 217                 printk(KERN_ERR "dlm_new_lockspace error %d", error);
 218
 219         return error;
 220 }
 221
 222 static void gdlm_unmount(struct gfs2_sbd *sdp)
 223 {
 224         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 225
 226         if (ls->ls_dlm) {
 227                 dlm_release_lockspace(ls->ls_dlm, 2);
 228                 ls->ls_dlm = NULL;
 229         }
 230 }
 231
 232 static const match_table_t dlm_tokens = {
 233         { Opt_jid, "jid=%d"},
 234         { Opt_id, "id=%d"},
 235         { Opt_first, "first=%d"},
 236         { Opt_nodir, "nodir=%d"},
 237         { Opt_err, NULL },
 238 };
 239
 240 const struct lm_lockops gfs2_dlm_ops = {
 241         .lm_proto_name = "lock_dlm",
 242         .lm_mount = gdlm_mount,
 243         .lm_unmount = gdlm_unmount,
 244         .lm_put_lock = gdlm_put_lock,
 245         .lm_lock = gdlm_lock,
 246         .lm_cancel = gdlm_cancel,
 247         .lm_tokens = &dlm_tokens,
 248 };
 249