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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
*
* 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 General Public License version 2.
*/
#include <linux/fs.h>
#include <linux/dlm.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/gfs2_ondisk.h>
#include "incore.h"
#include "glock.h"
#include "util.h"
static void gdlm_ast(void *arg)
{
struct gfs2_glock *gl = arg;
unsigned ret = gl->gl_state;
struct gfs2_sbd *sdp = gl->gl_sbd;
BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
if (gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID)
memset(gl->gl_lvb, 0, GDLM_LVB_SIZE);
switch (gl->gl_lksb.sb_status) {
case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
if (gl->gl_ops->go_flags & GLOF_ASPACE)
kmem_cache_free(gfs2_glock_aspace_cachep, gl);
else
kmem_cache_free(gfs2_glock_cachep, gl);
if (atomic_dec_and_test(&sdp->sd_glock_disposal))
wake_up(&sdp->sd_glock_wait);
return;
case -DLM_ECANCEL: /* Cancel while getting lock */
ret |= LM_OUT_CANCELED;
goto out;
case -EAGAIN: /* Try lock fails */
case -EDEADLK: /* Deadlock detected */
goto out;
case -ETIMEDOUT: /* Canceled due to timeout */
ret |= LM_OUT_ERROR;
goto out;
case 0: /* Success */
break;
default: /* Something unexpected */
BUG();
}
ret = gl->gl_req;
if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
if (gl->gl_req == LM_ST_SHARED)
ret = LM_ST_DEFERRED;
else if (gl->gl_req == LM_ST_DEFERRED)
ret = LM_ST_SHARED;
else
BUG();
}
set_bit(GLF_INITIAL, &gl->gl_flags);
gfs2_glock_complete(gl, ret);
return;
out:
if (!test_bit(GLF_INITIAL, &gl->gl_flags))
gl->gl_lksb.sb_lkid = 0;
gfs2_glock_complete(gl, ret);
}
static void gdlm_bast(void *arg, int mode)
{
struct gfs2_glock *gl = arg;
switch (mode) {
case DLM_LOCK_EX:
gfs2_glock_cb(gl, LM_ST_UNLOCKED);
break;
case DLM_LOCK_CW:
gfs2_glock_cb(gl, LM_ST_DEFERRED);
break;
case DLM_LOCK_PR:
gfs2_glock_cb(gl, LM_ST_SHARED);
break;
default:
printk(KERN_ERR "unknown bast mode %d", mode);
BUG();
}
}
/* convert gfs lock-state to dlm lock-mode */
static int make_mode(const unsigned int lmstate)
{
switch (lmstate) {
case LM_ST_UNLOCKED:
return DLM_LOCK_NL;
case LM_ST_EXCLUSIVE:
return DLM_LOCK_EX;
case LM_ST_DEFERRED:
return DLM_LOCK_CW;
case LM_ST_SHARED:
return DLM_LOCK_PR;
}
printk(KERN_ERR "unknown LM state %d", lmstate);
BUG();
return -1;
}
static u32 make_flags(const u32 lkid, const unsigned int gfs_flags,
const int req)
{
u32 lkf = 0;
if (gfs_flags & LM_FLAG_TRY)
lkf |= DLM_LKF_NOQUEUE;
if (gfs_flags & LM_FLAG_TRY_1CB) {
lkf |= DLM_LKF_NOQUEUE;
lkf |= DLM_LKF_NOQUEUEBAST;
}
if (gfs_flags & LM_FLAG_PRIORITY) {
lkf |= DLM_LKF_NOORDER;
lkf |= DLM_LKF_HEADQUE;
}
if (gfs_flags & LM_FLAG_ANY) {
if (req == DLM_LOCK_PR)
lkf |= DLM_LKF_ALTCW;
else if (req == DLM_LOCK_CW)
lkf |= DLM_LKF_ALTPR;
else
BUG();
}
if (lkid != 0)
lkf |= DLM_LKF_CONVERT;
lkf |= DLM_LKF_VALBLK;
return lkf;
}
static unsigned int gdlm_lock(struct gfs2_glock *gl,
unsigned int req_state, unsigned int flags)
{
struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
int error;
int req;
u32 lkf;
gl->gl_req = req_state;
req = make_mode(req_state);
lkf = make_flags(gl->gl_lksb.sb_lkid, flags, req);
/*
* Submit the actual lock request.
*/
error = dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, gl->gl_strname,
GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
if (error == -EAGAIN)
return 0;
if (error)
return LM_OUT_ERROR;
return LM_OUT_ASYNC;
}
static void gdlm_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
int error;
if (gl->gl_lksb.sb_lkid == 0) {
kmem_cache_free(cachep, gl);
if (atomic_dec_and_test(&sdp->sd_glock_disposal))
wake_up(&sdp->sd_glock_wait);
return;
}
error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
NULL, gl);
if (error) {
printk(KERN_ERR "gdlm_unlock %x,%llx err=%d\n",
gl->gl_name.ln_type,
(unsigned long long)gl->gl_name.ln_number, error);
return;
}
}
static void gdlm_cancel(struct gfs2_glock *gl)
{
struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
}
static int gdlm_mount(struct gfs2_sbd *sdp, const char *fsname)
{
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
int error;
if (fsname == NULL) {
fs_info(sdp, "no fsname found\n");
return -EINVAL;
}
error = dlm_new_lockspace(fsname, strlen(fsname), &ls->ls_dlm,
DLM_LSFL_FS | DLM_LSFL_NEWEXCL |
(ls->ls_nodir ? DLM_LSFL_NODIR : 0),
GDLM_LVB_SIZE);
if (error)
printk(KERN_ERR "dlm_new_lockspace error %d", error);
return error;
}
static void gdlm_unmount(struct gfs2_sbd *sdp)
{
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
if (ls->ls_dlm) {
dlm_release_lockspace(ls->ls_dlm, 2);
ls->ls_dlm = NULL;
}
}
static const match_table_t dlm_tokens = {
{ Opt_jid, "jid=%d"},
{ Opt_id, "id=%d"},
{ Opt_first, "first=%d"},
{ Opt_nodir, "nodir=%d"},
{ Opt_err, NULL },
};
const struct lm_lockops gfs2_dlm_ops = {
.lm_proto_name = "lock_dlm",
.lm_mount = gdlm_mount,
.lm_unmount = gdlm_unmount,
.lm_put_lock = gdlm_put_lock,
.lm_lock = gdlm_lock,
.lm_cancel = gdlm_cancel,
.lm_tokens = &dlm_tokens,
};
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