linux/fs/gfs2/lock_dlm.c
Steven Whitehouse 1fea7c25a0 GFS2: Update handling of DLM return codes to match reality
GFS2's idea of which return codes it needs to handle was based
upon those listed in dlm.h. Those didn't cover all the possible
codes and listed some which never happen. This updates GFS2 to
handle all the codes which can actually be returned from the
DLM under various circumstances.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-09-20 11:20:12 +01:00

251 lines
5.5 KiB
C

/*
* 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,
};