Here is my proposed fix for 428751. It needs some heavy testing, both
for correctness and performance, before it gets pushed.
-Ben
diff -urpN gfs2/glock.c gfs2-patched/glock.c
--- gfs2/glock.c 2008-03-04 10:54:02.000000000 -0600
+++ gfs2-patched/glock.c 2008-03-04 10:53:13.000000000 -0600
@@ -42,6 +42,7 @@
#include "quota.h"
#include "super.h"
#include "util.h"
+#include "lm_deadlk.h"
struct gfs2_gl_hash_bucket {
struct hlist_head hb_list;
@@ -785,7 +786,8 @@ static void xmote_bh(struct gfs2_glock *
state_change(gl, ret & LM_OUT_ST_MASK);
- if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) {
+ if ((prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) ||
+ ret & LM_OUT_DEADLK) {
if (glops->go_inval)
glops->go_inval(gl, DIO_METADATA);
} else if (gl->gl_state == LM_ST_DEFERRED) {
@@ -815,6 +817,15 @@ static void xmote_bh(struct gfs2_glock *
}
} else {
spin_lock(&gl->gl_spin);
+ if (ret & LM_OUT_DEADLK) {
+ gh->gh_error = 0;
+ gl->gl_req_bh = NULL;
+ set_bit(GLF_DEADLK, &gl->gl_flags);
+ spin_unlock(&gl->gl_spin);
+ gfs2_glock_drop_th(gl);
+ gfs2_glock_put(gl);
+ return;
+ }
list_del_init(&gh->gh_list);
gh->gh_error = -EIO;
if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
@@ -920,6 +931,16 @@ static void drop_bh(struct gfs2_glock *g
state_change(gl, LM_ST_UNLOCKED);
+ if (test_and_clear_bit(GLF_DEADLK, &gl->gl_flags)) {
+ spin_lock(&gl->gl_spin);
+ gh->gh_error = 0;
+ gl->gl_req_bh = NULL;
+ spin_unlock(&gl->gl_spin);
+ gfs2_glock_xmote_th(gl, gl->gl_req_gh);
+ gfs2_glock_put(gl);
+ return;
+ }
+
if (glops->go_inval)
glops->go_inval(gl, DIO_METADATA);
diff -urpN gfs2/incore.h gfs2-patched/incore.h
--- gfs2/incore.h 2008-03-04 10:54:02.000000000 -0600
+++ gfs2-patched/incore.h 2008-03-04 10:53:13.000000000 -0600
@@ -172,6 +172,7 @@ enum {
GLF_PENDING_DEMOTE = 4,
GLF_DIRTY = 5,
GLF_DEMOTE_IN_PROGRESS = 6,
+ GLF_DEADLK = 7,
};
struct gfs2_glock {
diff -urpN gfs2/lm.c gfs2-patched/lm.c
--- gfs2/lm.c 2008-03-04 10:54:02.000000000 -0600
+++ gfs2-patched/lm.c 2008-03-04 10:54:28.000000000 -0600
@@ -21,6 +21,7 @@
#include "lm.h"
#include "super.h"
#include "util.h"
+#include "lm_deadlk.h"
/**
* gfs2_lm_mount - mount a locking protocol
@@ -35,7 +36,7 @@ int gfs2_lm_mount(struct gfs2_sbd *sdp,
{
char *proto = sdp->sd_proto_name;
char *table = sdp->sd_table_name;
- int flags = 0;
+ int flags = LM_MFLAG_ALLOW_DEADLK;
int error;
if (sdp->sd_args.ar_spectator)
diff -urpN gfs2/lm_deadlk.h gfs2-patched/lm_deadlk.h
--- gfs2/lm_deadlk.h 1969-12-31 18:00:00.000000000 -0600
+++ gfs2-patched/lm_deadlk.h 2008-03-04 10:53:13.000000000 -0600
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+#ifndef __LM_DEADLK_DOT_H__
+#define __LM_DEADLK_DOT_H__
+
+/* This is a hack. These flags really belong in lm_interface.h */
+#define LM_OUT_DEADLK 0x00000200
+#define LM_MFLAG_ALLOW_DEADLK 0x00000002
+
+#endif /* __LM_DEADLK_DOT_H__ */
diff -urpN gfs2/locking/dlm/lock.c gfs2-patched/locking/dlm/lock.c
--- gfs2/locking/dlm/lock.c 2008-03-04 10:54:02.000000000 -0600
+++ gfs2-patched/locking/dlm/lock.c 2008-03-04 10:53:13.000000000 -0600
@@ -8,6 +8,7 @@
*/
#include "lock_dlm.h"
+#include "../../lm_deadlk.h"
static char junk_lvb[GDLM_LVB_SIZE];
@@ -137,7 +138,8 @@ static inline unsigned int make_flags(st
/* Conversion deadlock avoidance by DLM */
- if (!test_bit(LFL_FORCE_PROMOTE, &lp->flags) &&
+ if (!(lp->ls->fsflags & LM_MFLAG_ALLOW_DEADLK) &&
+ !test_bit(LFL_FORCE_PROMOTE, &lp->flags) &&
!(lkf & DLM_LKF_NOQUEUE) &&
cur > DLM_LOCK_NL && req > DLM_LOCK_NL && cur != req)
lkf |= DLM_LKF_CONVDEADLK;
diff -urpN gfs2/locking/dlm/thread.c gfs2-patched/locking/dlm/thread.c
--- gfs2/locking/dlm/thread.c 2008-03-04 10:54:02.000000000 -0600
+++ gfs2-patched/locking/dlm/thread.c 2008-03-04 10:53:13.000000000 -0600
@@ -8,6 +8,7 @@
*/
#include "lock_dlm.h"
+#include "../../lm_deadlk.h"
/* A lock placed on this queue is re-submitted to DLM as soon as the lock_dlm
thread gets to it. */
@@ -135,7 +136,15 @@ static void process_complete(struct gdlm
lp->lksb.sb_status, lp->lockname.ln_type,
(unsigned long long)lp->lockname.ln_number,
lp->flags);
- return;
+ if (lp->lksb.sb_status == -EDEADLOCK &&
+ lp->ls->fsflags & LM_MFLAG_ALLOW_DEADLK) {
+ lp->req = lp->cur;
+ acb.lc_ret |= LM_OUT_DEADLK;
+ if (lp->cur == DLM_LOCK_IV)
+ lp->lksb.sb_lkid = 0;
+ goto out;
+ } else
+ return;
}
/*
