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