[DLM] overlapping cancel and unlock [13/34]

Steven Whitehouse
2007-05-01T10:13:50Z

>From ef0c2bb05f40f9a0cd2deae63e199bfa62faa7fa Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Wed, 28 Mar 2007 09:56:46 -0500
Subject: [PATCH] [DLM] overlapping cancel and unlock

Full cancel and force-unlock support. In the past, cancel and
force-unlock
wouldn't work if there was another operation in progress on the lock.
Now,
both cancel and unlock-force can overlap an operation on a lock, meaning
there
may be 2 or 3 operations in progress on a lock in parallel. This
support is
important not only because cancel and force-unlock are explicit
operations
that an app can use, but both are used implicitly when a process exits
while
holding locks.

Summary of changes:

- add-to and remove-from waiters functions were rewritten to handle
situations
with more than one remote operation outstanding on a lock

- validate_unlock_args detects when an overlapping cancel/unlock-force
can be sent and when it needs to be delayed until a request/lookup
reply is received

- processing request/lookup replies detects when cancel/unlock-force
occured during the op, and carries out the delayed cancel/unlock-force

- manipulation of the "waiters" (remote operation) state of a lock moved
under
the standard rsb mutex that protects all the other lock state

- the two recovery routines related to locks on the waiters list changed
according to the way lkb's are now locked before accessing waiters
state

- waiters recovery detects when lkb's being recovered have overlapping
cancel/unlock-force, and may not recover such locks

- revert_lock (cancel) returns a value to distinguish cases where it did
nothing vs cases where it actually did a cancel; the cancel completion
ast
should only be done when cancel did something

- orphaned locks put on new list so they can be found later for purging

- cancel must be called on a lock when making it an orphan

- flag user locks (ENDOFLIFE) at the end of their useful life (to the
application) so we can return an error for any further
cancel/unlock-force

- we weren't setting COMP/BAST ast flags if one was already set, so we'd
lose
either a completion or blocking ast

- clear an unread bast on a lock that's become unlocked

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 61d9320..178931c 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -2,7 +2,7 @@

*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights
reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2007 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
@@ -210,6 +210,9 @@ struct dlm_args {
#define DLM_IFL_MSTCPY 0x00010000
#define DLM_IFL_RESEND 0x00020000
#define DLM_IFL_DEAD 0x00040000
+#define DLM_IFL_OVERLAP_UNLOCK 0x00080000
+#define DLM_IFL_OVERLAP_CANCEL 0x00100000
+#define DLM_IFL_ENDOFLIFE 0x00200000
#define DLM_IFL_USER 0x00000001
#define DLM_IFL_ORPHAN 0x00000002

@@ -230,8 +233,8 @@ struct dlm_lkb {
int8_t lkb_grmode; /* granted lock mode */
int8_t lkb_bastmode; /* requested mode */
int8_t lkb_highbast; /* highest mode bast sent for */
-
int8_t lkb_wait_type; /* type of reply waiting for */
+ int8_t lkb_wait_count;
int8_t lkb_ast_type; /* type of ast queued for */

struct list_head lkb_idtbl_list; /* lockspace lkbtbl */
@@ -440,6 +443,9 @@ struct dlm_ls {
struct mutex ls_waiters_mutex;
struct list_head ls_waiters; /* lkbs needing a reply */

+ struct mutex ls_orphans_mutex;
+ struct list_head ls_orphans;
+
struct list_head ls_nodes; /* current nodes in ls */
struct list_head ls_nodes_gone; /* dead node list, recovery */
int ls_num_nodes; /* number of nodes in ls */
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index e725005..b865a46 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -1,7 +1,7 @@
/******************************************************************************

*******************************************************************************
**
-** Copyright (C) 2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2005-2007 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
@@ -254,6 +254,22 @@ static inline int down_conversion(struct dlm_lkb
*lkb)
return (!middle_conversion(lkb) && lkb->lkb_rqmode < lkb->lkb_grmode);
}

+static inline int is_overlap_unlock(struct dlm_lkb *lkb)
+{
+ return lkb->lkb_flags & DLM_IFL_OVERLAP_UNLOCK;
+}
+
+static inline int is_overlap_cancel(struct dlm_lkb *lkb)
+{
+ return lkb->lkb_flags & DLM_IFL_OVERLAP_CANCEL;
+}
+
+static inline int is_overlap(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_flags & (DLM_IFL_OVERLAP_UNLOCK |
+ DLM_IFL_OVERLAP_CANCEL));
+}
+
static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
{
if (is_master_copy(lkb))
@@ -267,6 +283,12 @@ static void queue_cast(struct dlm_rsb *r, struct
dlm_lkb *lkb, int rv)
dlm_add_ast(lkb, AST_COMP);
}

+static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb
*lkb)
+{
+ queue_cast(r, lkb,
+ is_overlap_unlock(lkb) ? -DLM_EUNLOCK : -DLM_ECANCEL);
+}
+
static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int
rqmode)
{
if (is_master_copy(lkb))
@@ -547,6 +569,7 @@ static int create_lkb(struct dlm_ls *ls, struct
dlm_lkb **lkb_ret)
lkb->lkb_grmode = DLM_LOCK_IV;
kref_init(&lkb->lkb_ref);
INIT_LIST_HEAD(&lkb->lkb_ownqueue);
+ INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);

get_random_bytes(&bucket, sizeof(bucket));
bucket &= (ls->ls_lkbtbl_size - 1);
@@ -735,23 +758,75 @@ static void move_lkb(struct dlm_rsb *r, struct
dlm_lkb *lkb, int sts)
unhold_lkb(lkb);
}

+static int msg_reply_type(int mstype)
+{
+ switch (mstype) {
+ case DLM_MSG_REQUEST:
+ return DLM_MSG_REQUEST_REPLY;
+ case DLM_MSG_CONVERT:
+ return DLM_MSG_CONVERT_REPLY;
+ case DLM_MSG_UNLOCK:
+ return DLM_MSG_UNLOCK_REPLY;
+ case DLM_MSG_CANCEL:
+ return DLM_MSG_CANCEL_REPLY;
+ case DLM_MSG_LOOKUP:
+ return DLM_MSG_LOOKUP_REPLY;
+ }
+ return -1;
+}
+
/* add/remove lkb from global waiters list of lkb's waiting for
a reply from a remote node */

-static void add_to_waiters(struct dlm_lkb *lkb, int mstype)
+static int add_to_waiters(struct dlm_lkb *lkb, int mstype)
{
struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ int error = 0;

mutex_lock(&ls->ls_waiters_mutex);
- if (lkb->lkb_wait_type) {
- log_print("add_to_waiters error %d", lkb->lkb_wait_type);
+
+ if (is_overlap_unlock(lkb) ||
+ (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL))) {
+ error = -EINVAL;
+ goto out;
+ }
+
+ if (lkb->lkb_wait_type || is_overlap_cancel(lkb)) {
+ switch (mstype) {
+ case DLM_MSG_UNLOCK:
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
+ break;
+ case DLM_MSG_CANCEL:
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
+ break;
+ default:
+ error = -EBUSY;
+ goto out;
+ }
+ lkb->lkb_wait_count++;
+ hold_lkb(lkb);
+
+ log_debug(ls, "add overlap %x cur %d new %d count %d flags %x",
+ lkb->lkb_id, lkb->lkb_wait_type, mstype,
+ lkb->lkb_wait_count, lkb->lkb_flags);
goto out;
}
+
+ DLM_ASSERT(!lkb->lkb_wait_count,
+ dlm_print_lkb(lkb);
+ printk("wait_count %d\n", lkb->lkb_wait_count););
+
+ lkb->lkb_wait_count++;
lkb->lkb_wait_type = mstype;
- kref_get(&lkb->lkb_ref);
+ hold_lkb(lkb);
list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
out:
+ if (error)
+ log_error(ls, "add_to_waiters %x error %d flags %x %d %d %s",
+ lkb->lkb_id, error, lkb->lkb_flags, mstype,
+ lkb->lkb_wait_type, lkb->lkb_resource->res_name);
mutex_unlock(&ls->ls_waiters_mutex);
+ return error;
}

/* We clear the RESEND flag because we might be taking an lkb off the
waiters
@@ -759,34 +834,85 @@ static void add_to_waiters(struct dlm_lkb *lkb,
int mstype)
request reply on the requestqueue) between dlm_recover_waiters_pre()
which
set RESEND and dlm_recover_waiters_post() */

-static int _remove_from_waiters(struct dlm_lkb *lkb)
+static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype)
{
- int error = 0;
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ int overlap_done = 0;

- if (!lkb->lkb_wait_type) {
- log_print("remove_from_waiters error");
- error = -EINVAL;
- goto out;
+ if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
+ overlap_done = 1;
+ goto out_del;
}
- lkb->lkb_wait_type = 0;
+
+ if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
+ overlap_done = 1;
+ goto out_del;
+ }
+
+ /* N.B. type of reply may not always correspond to type of original
+ msg due to lookup->request optimization, verify others? */
+
+ if (lkb->lkb_wait_type) {
+ lkb->lkb_wait_type = 0;
+ goto out_del;
+ }
+
+ log_error(ls, "remove_from_waiters lkid %x flags %x types %d %d",
+ lkb->lkb_id, lkb->lkb_flags, mstype, lkb->lkb_wait_type);
+ return -1;
+
+ out_del:
+ /* the force-unlock/cancel has completed and we haven't recvd a reply
+ to the op that was in progress prior to the unlock/cancel; we
+ give up on any reply to the earlier op. FIXME: not sure when/how
+ this would happen */
+
+ if (overlap_done && lkb->lkb_wait_type) {
+ log_error(ls, "remove_from_waiters %x reply %d give up on %d",
+ lkb->lkb_id, mstype, lkb->lkb_wait_type);
+ lkb->lkb_wait_count--;
+ lkb->lkb_wait_type = 0;
+ }
+
+ DLM_ASSERT(lkb->lkb_wait_count, dlm_print_lkb(lkb););
+
lkb->lkb_flags &= ~DLM_IFL_RESEND;
- list_del(&lkb->lkb_wait_reply);
+ lkb->lkb_wait_count--;
+ if (!lkb->lkb_wait_count)
+ list_del_init(&lkb->lkb_wait_reply);
unhold_lkb(lkb);
- out:
- return error;
+ return 0;
}

-static int remove_from_waiters(struct dlm_lkb *lkb)
+static int remove_from_waiters(struct dlm_lkb *lkb, int mstype)
{
struct dlm_ls *ls = lkb->lkb_resource->res_ls;
int error;

mutex_lock(&ls->ls_waiters_mutex);
- error = _remove_from_waiters(lkb);
+ error = _remove_from_waiters(lkb, mstype);
mutex_unlock(&ls->ls_waiters_mutex);
return error;
}

+/* Handles situations where we might be processing a "fake" or "stub"
reply in
+ which we can't try to take waiters_mutex again. */
+
+static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct
dlm_message *ms)
+{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+ int error;
+
+ if (ms != &ls->ls_stub_ms)
+ mutex_lock(&ls->ls_waiters_mutex);
+ error = _remove_from_waiters(lkb, ms->m_type);
+ if (ms != &ls->ls_stub_ms)
+ mutex_unlock(&ls->ls_waiters_mutex);
+ return error;
+}
+
static void dir_remove(struct dlm_rsb *r)
{
int to_nodeid;
@@ -988,8 +1114,14 @@ static void remove_lock_pc(struct dlm_rsb *r,
struct dlm_lkb *lkb)
_remove_lock(r, lkb);
}

-static void revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
+/* returns: 0 did nothing
+ 1 moved lock to granted
+ -1 removed lock */
+
+static int revert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
+ int rv = 0;
+
lkb->lkb_rqmode = DLM_LOCK_IV;

switch (lkb->lkb_status) {
@@ -997,6 +1129,7 @@ static void revert_lock(struct dlm_rsb *r, struct
dlm_lkb *lkb)
break;
case DLM_LKSTS_CONVERT:
move_lkb(r, lkb, DLM_LKSTS_GRANTED);
+ rv = 1;
break;
case DLM_LKSTS_WAITING:
del_lkb(r, lkb);
@@ -1004,15 +1137,17 @@ static void revert_lock(struct dlm_rsb *r,
struct dlm_lkb *lkb)
/* this unhold undoes the original ref from create_lkb()
so this leads to the lkb being freed */
unhold_lkb(lkb);
+ rv = -1;
break;
default:
log_print("invalid status for revert %d", lkb->lkb_status);
}
+ return rv;
}

-static void revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
+static int revert_lock_pc(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
- revert_lock(r, lkb);
+ return revert_lock(r, lkb);
}

static void _grant_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -1499,7 +1634,7 @@ static void process_lookup_list(struct dlm_rsb *r)
struct dlm_lkb *lkb, *safe;

list_for_each_entry_safe(lkb, safe, &r->res_lookup, lkb_rsb_lookup) {
- list_del(&lkb->lkb_rsb_lookup);
+ list_del_init(&lkb->lkb_rsb_lookup);
_request_lock(r, lkb);
schedule();
}
@@ -1530,7 +1665,7 @@ static void confirm_master(struct dlm_rsb *r, int
error)
if (!list_empty(&r->res_lookup)) {
lkb = list_entry(r->res_lookup.next, struct dlm_lkb,
lkb_rsb_lookup);
- list_del(&lkb->lkb_rsb_lookup);
+ list_del_init(&lkb->lkb_rsb_lookup);
r->res_first_lkid = lkb->lkb_id;
_request_lock(r, lkb);
} else
@@ -1614,6 +1749,9 @@ static int set_unlock_args(uint32_t flags, void
*astarg, struct dlm_args *args)
DLM_LKF_FORCEUNLOCK))
return -EINVAL;

+ if (flags & DLM_LKF_CANCEL && flags & DLM_LKF_FORCEUNLOCK)
+ return -EINVAL;
+
args->flags = flags;
args->astparam = (long) astarg;
return 0;
@@ -1638,6 +1776,9 @@ static int validate_lock_args(struct dlm_ls *ls,
struct dlm_lkb *lkb,

if (lkb->lkb_wait_type)
goto out;
+
+ if (is_overlap(lkb))
+ goto out;
}

lkb->lkb_exflags = args->flags;
@@ -1654,35 +1795,126 @@ static int validate_lock_args(struct dlm_ls
*ls, struct dlm_lkb *lkb,
return rv;
}

+/* when dlm_unlock() sees -EBUSY with CANCEL/FORCEUNLOCK it returns 0
+ for success */
+
+/* note: it's valid for lkb_nodeid/res_nodeid to be -1 when we get here
+ because there may be a lookup in progress and it's valid to do
+ cancel/unlockf on it */
+
static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args
*args)
{
+ struct dlm_ls *ls = lkb->lkb_resource->res_ls;
int rv = -EINVAL;

- if (lkb->lkb_flags & DLM_IFL_MSTCPY)
+ if (lkb->lkb_flags & DLM_IFL_MSTCPY) {
+ log_error(ls, "unlock on MSTCPY %x", lkb->lkb_id);
+ dlm_print_lkb(lkb);
goto out;
+ }

- if (args->flags & DLM_LKF_FORCEUNLOCK)
- goto out_ok;
+ /* an lkb may still exist even though the lock is EOL'ed due to a
+ cancel, unlock or failed noqueue request; an app can't use these
+ locks; return same error as if the lkid had not been found at all
*/

- if (args->flags & DLM_LKF_CANCEL &&
- lkb->lkb_status == DLM_LKSTS_GRANTED)
+ if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
+ log_debug(ls, "unlock on ENDOFLIFE %x", lkb->lkb_id);
+ rv = -ENOENT;
goto out;
+ }

- if (!(args->flags & DLM_LKF_CANCEL) &&
- lkb->lkb_status != DLM_LKSTS_GRANTED)
- goto out;
+ /* an lkb may be waiting for an rsb lookup to complete where the
+ lookup was initiated by another lock */
+
+ if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
+ if (!list_empty(&lkb->lkb_rsb_lookup)) {
+ log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
+ list_del_init(&lkb->lkb_rsb_lookup);
+ queue_cast(lkb->lkb_resource, lkb,
+ args->flags & DLM_LKF_CANCEL ?
+ -DLM_ECANCEL : -DLM_EUNLOCK);
+ unhold_lkb(lkb); /* undoes create_lkb() */
+ rv = -EBUSY;
+ goto out;
+ }
+ }
+
+ /* cancel not allowed with another cancel/unlock in progress */
+
+ if (args->flags & DLM_LKF_CANCEL) {
+ if (lkb->lkb_exflags & DLM_LKF_CANCEL)
+ goto out;
+
+ if (is_overlap(lkb))
+ goto out;
+
+ if (lkb->lkb_flags & DLM_IFL_RESEND) {
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
+ rv = -EBUSY;
+ goto out;
+ }
+
+ switch (lkb->lkb_wait_type) {
+ case DLM_MSG_LOOKUP:
+ case DLM_MSG_REQUEST:
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
+ rv = -EBUSY;
+ goto out;
+ case DLM_MSG_UNLOCK:
+ case DLM_MSG_CANCEL:
+ goto out;
+ }
+ /* add_to_waiters() will set OVERLAP_CANCEL */
+ goto out_ok;
+ }
+
+ /* do we need to allow a force-unlock if there's a normal unlock
+ already in progress? in what conditions could the normal unlock
+ fail such that we'd want to send a force-unlock to be sure? */
+
+ if (args->flags & DLM_LKF_FORCEUNLOCK) {
+ if (lkb->lkb_exflags & DLM_LKF_FORCEUNLOCK)
+ goto out;
+
+ if (is_overlap_unlock(lkb))
+ goto out;

+ if (lkb->lkb_flags & DLM_IFL_RESEND) {
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
+ rv = -EBUSY;
+ goto out;
+ }
+
+ switch (lkb->lkb_wait_type) {
+ case DLM_MSG_LOOKUP:
+ case DLM_MSG_REQUEST:
+ lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
+ rv = -EBUSY;
+ goto out;
+ case DLM_MSG_UNLOCK:
+ goto out;
+ }
+ /* add_to_waiters() will set OVERLAP_UNLOCK */
+ goto out_ok;
+ }
+
+ /* normal unlock not allowed if there's any op in progress */
rv = -EBUSY;
- if (lkb->lkb_wait_type)
+ if (lkb->lkb_wait_type || lkb->lkb_wait_count)
goto out;

out_ok:
- lkb->lkb_exflags = args->flags;
+ /* an overlapping op shouldn't blow away exflags from other op */
+ lkb->lkb_exflags |= args->flags;
lkb->lkb_sbflags = 0;
lkb->lkb_astparam = args->astparam;
-
rv = 0;
out:
+ if (rv)
+ log_debug(ls, "validate_unlock_args %d %x %x %x %x %d %s", rv,
+ lkb->lkb_id, lkb->lkb_flags, lkb->lkb_exflags,
+ args->flags, lkb->lkb_wait_type,
+ lkb->lkb_resource->res_name);
return rv;
}

@@ -1759,17 +1991,19 @@ static int do_unlock(struct dlm_rsb *r, struct
dlm_lkb *lkb)
return -DLM_EUNLOCK;
}

-/* FIXME: if revert_lock() finds that the lkb is granted, we should
- skip the queue_cast(ECANCEL). It indicates that the request/convert
- completed (and queued a normal ast) just before the cancel; we don't
- want to clobber the sb_result for the normal ast with ECANCEL. */
+/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */

static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
- revert_lock(r, lkb);
- queue_cast(r, lkb, -DLM_ECANCEL);
- grant_pending_locks(r);
- return -DLM_ECANCEL;
+ int error;
+
+ error = revert_lock(r, lkb);
+ if (error) {
+ queue_cast(r, lkb, -DLM_ECANCEL);
+ grant_pending_locks(r);
+ return -DLM_ECANCEL;
+ }
+ return 0;
}

/*
@@ -2035,6 +2269,8 @@ int dlm_unlock(dlm_lockspace_t *lockspace,

if (error == -DLM_EUNLOCK || error == -DLM_ECANCEL)
error = 0;
+ if (error == -EBUSY && (flags & (DLM_LKF_CANCEL |
DLM_LKF_FORCEUNLOCK)))
+ error = 0;
out_put:
dlm_put_lkb(lkb);
out:
@@ -2176,7 +2412,9 @@ static int send_common(struct dlm_rsb *r, struct
dlm_lkb *lkb, int mstype)
struct dlm_mhandle *mh;
int to_nodeid, error;

- add_to_waiters(lkb, mstype);
+ error = add_to_waiters(lkb, mstype);
+ if (error)
+ return error;

to_nodeid = r->res_nodeid;

@@ -2192,7 +2430,7 @@ static int send_common(struct dlm_rsb *r, struct
dlm_lkb *lkb, int mstype)
return 0;

fail:
- remove_from_waiters(lkb);
+ remove_from_waiters(lkb, msg_reply_type(mstype));
return error;
}

@@ -2209,7 +2447,8 @@ static int send_convert(struct dlm_rsb *r, struct
dlm_lkb *lkb)

/* down conversions go without a reply from the master */
if (!error && down_conversion(lkb)) {
- remove_from_waiters(lkb);
+ remove_from_waiters(lkb, DLM_MSG_CONVERT_REPLY);
+ r->res_ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
r->res_ls->ls_stub_ms.m_result = 0;
r->res_ls->ls_stub_ms.m_flags = lkb->lkb_flags;
__receive_convert_reply(r, lkb, &r->res_ls->ls_stub_ms);
@@ -2280,7 +2519,9 @@ static int send_lookup(struct dlm_rsb *r, struct
dlm_lkb *lkb)
struct dlm_mhandle *mh;
int to_nodeid, error;

- add_to_waiters(lkb, DLM_MSG_LOOKUP);
+ error = add_to_waiters(lkb, DLM_MSG_LOOKUP);
+ if (error)
+ return error;

to_nodeid = dlm_dir_nodeid(r);

@@ -2296,7 +2537,7 @@ static int send_lookup(struct dlm_rsb *r, struct
dlm_lkb *lkb)
return 0;

fail:
- remove_from_waiters(lkb);
+ remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
return error;
}

@@ -2740,7 +2981,7 @@ static void receive_request_reply(struct dlm_ls
*ls, struct dlm_message *ms)
{
struct dlm_lkb *lkb;
struct dlm_rsb *r;
- int error, mstype;
+ int error, mstype, result;

error = find_lkb(ls, ms->m_remid, &lkb);
if (error) {
@@ -2749,20 +2990,15 @@ static void receive_request_reply(struct dlm_ls
*ls, struct dlm_message *ms)
}
DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););

- mstype = lkb->lkb_wait_type;
- error = remove_from_waiters(lkb);
- if (error) {
- log_error(ls, "receive_request_reply not on waiters");
- goto out;
- }
-
- /* this is the value returned from do_request() on the master */
- error = ms->m_result;
-
r = lkb->lkb_resource;
hold_rsb(r);
lock_rsb(r);

+ mstype = lkb->lkb_wait_type;
+ error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY);
+ if (error)
+ goto out;
+
/* Optimization: the dir node was also the master, so it took our
lookup as a request and sent request reply instead of lookup reply
*/
if (mstype == DLM_MSG_LOOKUP) {
@@ -2770,14 +3006,15 @@ static void receive_request_reply(struct dlm_ls
*ls, struct dlm_message *ms)
lkb->lkb_nodeid = r->res_nodeid;
}

- switch (error) {
+ /* this is the value returned from do_request() on the master */
+ result = ms->m_result;
+
+ switch (result) {
case -EAGAIN:
- /* request would block (be queued) on remote master;
- the unhold undoes the original ref from create_lkb()
- so it leads to the lkb being freed */
+ /* request would block (be queued) on remote master */
queue_cast(r, lkb, -EAGAIN);
confirm_master(r, -EAGAIN);
- unhold_lkb(lkb);
+ unhold_lkb(lkb); /* undoes create_lkb() */
break;

case -EINPROGRESS:
@@ -2785,41 +3022,62 @@ static void receive_request_reply(struct dlm_ls
*ls, struct dlm_message *ms)
/* request was queued or granted on remote master */
receive_flags_reply(lkb, ms);
lkb->lkb_remid = ms->m_lkid;
- if (error)
+ if (result)
add_lkb(r, lkb, DLM_LKSTS_WAITING);
else {
grant_lock_pc(r, lkb, ms);
queue_cast(r, lkb, 0);
}
- confirm_master(r, error);
+ confirm_master(r, result);
break;

case -EBADR:
case -ENOTBLK:
/* find_rsb failed to find rsb or rsb wasn't master */
+ log_debug(ls, "receive_request_reply %x %x master diff %d %d",
+ lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result);
r->res_nodeid = -1;
lkb->lkb_nodeid = -1;
- _request_lock(r, lkb);
+
+ if (is_overlap(lkb)) {
+ /* we'll ignore error in cancel/unlock reply */
+ queue_cast_overlap(r, lkb);
+ unhold_lkb(lkb); /* undoes create_lkb() */
+ } else
+ _request_lock(r, lkb);
break;

default:
- log_error(ls, "receive_request_reply error %d", error);
+ log_error(ls, "receive_request_reply %x error %d",
+ lkb->lkb_id, result);
}

+ if (is_overlap_unlock(lkb) && (result == 0 || result == -EINPROGRESS))
{
+ log_debug(ls, "receive_request_reply %x result %d unlock",
+ lkb->lkb_id, result);
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
+ send_unlock(r, lkb);
+ } else if (is_overlap_cancel(lkb) && (result == -EINPROGRESS)) {
+ log_debug(ls, "receive_request_reply %x cancel", lkb->lkb_id);
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
+ send_cancel(r, lkb);
+ } else {
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
+ }
+ out:
unlock_rsb(r);
put_rsb(r);
- out:
dlm_put_lkb(lkb);
}

static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb
*lkb,
struct dlm_message *ms)
{
- int error = ms->m_result;
-
/* this is the value returned from do_convert() on the master */
-
- switch (error) {
+ switch (ms->m_result) {
case -EAGAIN:
/* convert would block (be queued) on remote master */
queue_cast(r, lkb, -EAGAIN);
@@ -2839,19 +3097,26 @@ static void __receive_convert_reply(struct
dlm_rsb *r, struct dlm_lkb *lkb,
break;

default:
- log_error(r->res_ls, "receive_convert_reply error %d", error);
+ log_error(r->res_ls, "receive_convert_reply %x error %d",
+ lkb->lkb_id, ms->m_result);
}
}

static void _receive_convert_reply(struct dlm_lkb *lkb, struct
dlm_message *ms)
{
struct dlm_rsb *r = lkb->lkb_resource;
+ int error;

hold_rsb(r);
lock_rsb(r);

- __receive_convert_reply(r, lkb, ms);
+ /* stub reply can happen with waiters_mutex held */
+ error = remove_from_waiters_ms(lkb, ms);
+ if (error)
+ goto out;

+ __receive_convert_reply(r, lkb, ms);
+ out:
unlock_rsb(r);
put_rsb(r);
}
@@ -2868,37 +3133,38 @@ static void receive_convert_reply(struct dlm_ls
*ls, struct dlm_message *ms)
}
DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););

- error = remove_from_waiters(lkb);
- if (error) {
- log_error(ls, "receive_convert_reply not on waiters");
- goto out;
- }
-
_receive_convert_reply(lkb, ms);
- out:
dlm_put_lkb(lkb);
}

static void _receive_unlock_reply(struct dlm_lkb *lkb, struct
dlm_message *ms)
{
struct dlm_rsb *r = lkb->lkb_resource;
- int error = ms->m_result;
+ int error;

hold_rsb(r);
lock_rsb(r);

+ /* stub reply can happen with waiters_mutex held */
+ error = remove_from_waiters_ms(lkb, ms);
+ if (error)
+ goto out;
+
/* this is the value returned from do_unlock() on the master */

- switch (error) {
+ switch (ms->m_result) {
case -DLM_EUNLOCK:
receive_flags_reply(lkb, ms);
remove_lock_pc(r, lkb);
queue_cast(r, lkb, -DLM_EUNLOCK);
break;
+ case -ENOENT:
+ break;
default:
- log_error(r->res_ls, "receive_unlock_reply error %d", error);
+ log_error(r->res_ls, "receive_unlock_reply %x error %d",
+ lkb->lkb_id, ms->m_result);
}
-
+ out:
unlock_rsb(r);
put_rsb(r);
}
@@ -2915,37 +3181,39 @@ static void receive_unlock_reply(struct dlm_ls
*ls, struct dlm_message *ms)
}
DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););

- error = remove_from_waiters(lkb);
- if (error) {
- log_error(ls, "receive_unlock_reply not on waiters");
- goto out;
- }
-
_receive_unlock_reply(lkb, ms);
- out:
dlm_put_lkb(lkb);
}

static void _receive_cancel_reply(struct dlm_lkb *lkb, struct
dlm_message *ms)
{
struct dlm_rsb *r = lkb->lkb_resource;
- int error = ms->m_result;
+ int error;

hold_rsb(r);
lock_rsb(r);

+ /* stub reply can happen with waiters_mutex held */
+ error = remove_from_waiters_ms(lkb, ms);
+ if (error)
+ goto out;
+
/* this is the value returned from do_cancel() on the master */

- switch (error) {
+ switch (ms->m_result) {
case -DLM_ECANCEL:
receive_flags_reply(lkb, ms);
revert_lock_pc(r, lkb);
- queue_cast(r, lkb, -DLM_ECANCEL);
+ if (ms->m_result)
+ queue_cast(r, lkb, -DLM_ECANCEL);
+ break;
+ case 0:
break;
default:
- log_error(r->res_ls, "receive_cancel_reply error %d", error);
+ log_error(r->res_ls, "receive_cancel_reply %x error %d",
+ lkb->lkb_id, ms->m_result);
}
-
+ out:
unlock_rsb(r);
put_rsb(r);
}
@@ -2962,14 +3230,7 @@ static void receive_cancel_reply(struct dlm_ls
*ls, struct dlm_message *ms)
}
DLM_ASSERT(is_process_copy(lkb), dlm_print_lkb(lkb););

- error = remove_from_waiters(lkb);
- if (error) {
- log_error(ls, "receive_cancel_reply not on waiters");
- goto out;
- }
-
_receive_cancel_reply(lkb, ms);
- out:
dlm_put_lkb(lkb);
}

@@ -2985,20 +3246,17 @@ static void receive_lookup_reply(struct dlm_ls
*ls, struct dlm_message *ms)
return;
}

- error = remove_from_waiters(lkb);
- if (error) {
- log_error(ls, "receive_lookup_reply not on waiters");
- goto out;
- }
-
- /* this is the value returned by dlm_dir_lookup on dir node
+ /* ms->m_result is the value returned by dlm_dir_lookup on dir node
FIXME: will a non-zero error ever be returned? */
- error = ms->m_result;

r = lkb->lkb_resource;
hold_rsb(r);
lock_rsb(r);

+ error = remove_from_waiters(lkb, DLM_MSG_LOOKUP_REPLY);
+ if (error)
+ goto out;
+
ret_nodeid = ms->m_nodeid;
if (ret_nodeid == dlm_our_nodeid()) {
r->res_nodeid = 0;
@@ -3009,14 +3267,22 @@ static void receive_lookup_reply(struct dlm_ls
*ls, struct dlm_message *ms)
r->res_nodeid = ret_nodeid;
}

+ if (is_overlap(lkb)) {
+ log_debug(ls, "receive_lookup_reply %x unlock %x",
+ lkb->lkb_id, lkb->lkb_flags);
+ queue_cast_overlap(r, lkb);
+ unhold_lkb(lkb); /* undoes create_lkb() */
+ goto out_list;
+ }
+
_request_lock(r, lkb);

+ out_list:
if (!ret_nodeid)
process_lookup_list(r);
-
+ out:
unlock_rsb(r);
put_rsb(r);
- out:
dlm_put_lkb(lkb);
}

@@ -3153,9 +3419,9 @@ static void recover_convert_waiter(struct dlm_ls
*ls, struct dlm_lkb *lkb)
{
if (middle_conversion(lkb)) {
hold_lkb(lkb);
+ ls->ls_stub_ms.m_type = DLM_MSG_CONVERT_REPLY;
ls->ls_stub_ms.m_result = -EINPROGRESS;
ls->ls_stub_ms.m_flags = lkb->lkb_flags;
- _remove_from_waiters(lkb);
_receive_convert_reply(lkb, &ls->ls_stub_ms);

/* Same special case as in receive_rcom_lock_args() */
@@ -3227,18 +3493,18 @@ void dlm_recover_waiters_pre(struct dlm_ls *ls)

case DLM_MSG_UNLOCK:
hold_lkb(lkb);
+ ls->ls_stub_ms.m_type = DLM_MSG_UNLOCK_REPLY;
ls->ls_stub_ms.m_result = -DLM_EUNLOCK;
ls->ls_stub_ms.m_flags = lkb->lkb_flags;
- _remove_from_waiters(lkb);
_receive_unlock_reply(lkb, &ls->ls_stub_ms);
dlm_put_lkb(lkb);
break;

case DLM_MSG_CANCEL:
hold_lkb(lkb);
+ ls->ls_stub_ms.m_type = DLM_MSG_CANCEL_REPLY;
ls->ls_stub_ms.m_result = -DLM_ECANCEL;
ls->ls_stub_ms.m_flags = lkb->lkb_flags;
- _remove_from_waiters(lkb);
_receive_cancel_reply(lkb, &ls->ls_stub_ms);
dlm_put_lkb(lkb);
break;
@@ -3252,37 +3518,47 @@ void dlm_recover_waiters_pre(struct dlm_ls *ls)
mutex_unlock(&ls->ls_waiters_mutex);
}

-static int remove_resend_waiter(struct dlm_ls *ls, struct dlm_lkb
**lkb_ret)
+static struct dlm_lkb *find_resend_waiter(struct dlm_ls *ls)
{
struct dlm_lkb *lkb;
- int rv = 0;
+ int found = 0;

mutex_lock(&ls->ls_waiters_mutex);
list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
if (lkb->lkb_flags & DLM_IFL_RESEND) {
- rv = lkb->lkb_wait_type;
- _remove_from_waiters(lkb);
- lkb->lkb_flags &= ~DLM_IFL_RESEND;
+ hold_lkb(lkb);
+ found = 1;
break;
}
}
mutex_unlock(&ls->ls_waiters_mutex);

- if (!rv)
+ if (!found)
lkb = NULL;
- *lkb_ret = lkb;
- return rv;
+ return lkb;
}

/* Deal with lookups and lkb's marked RESEND from _pre. We may now be
the
master or dir-node for r. Processing the lkb may result in it being
placed
back on waiters. */

+/* We do this after normal locking has been enabled and any saved
messages
+ (in requestqueue) have been processed. We should be confident that
at
+ this point we won't get or process a reply to any of these waiting
+ operations. But, new ops may be coming in on the rsbs/locks here
from
+ userspace or remotely. */
+
+/* there may have been an overlap unlock/cancel prior to recovery or
after
+ recovery. if before, the lkb may still have a pos wait_count; if
after, the
+ overlap flag would just have been set and nothing new sent. we can
be
+ confident here than any replies to either the initial op or overlap
ops
+ prior to recovery have been received. */
+
int dlm_recover_waiters_post(struct dlm_ls *ls)
{
struct dlm_lkb *lkb;
struct dlm_rsb *r;
- int error = 0, mstype;
+ int error = 0, mstype, err, oc, ou;

while (1) {
if (dlm_locking_stopped(ls)) {
@@ -3291,48 +3567,78 @@ int dlm_recover_waiters_post(struct dlm_ls *ls)
break;
}

- mstype = remove_resend_waiter(ls, &lkb);
- if (!mstype)
+ lkb = find_resend_waiter(ls);
+ if (!lkb)
break;

r = lkb->lkb_resource;
+ hold_rsb(r);
+ lock_rsb(r);
+
+ mstype = lkb->lkb_wait_type;
+ oc = is_overlap_cancel(lkb);
+ ou = is_overlap_unlock(lkb);
+ err = 0;

log_debug(ls, "recover_waiters_post %x type %d flags %x %s",
lkb->lkb_id, mstype, lkb->lkb_flags, r->res_name);

- switch (mstype) {
-
- case DLM_MSG_LOOKUP:
- hold_rsb(r);
- lock_rsb(r);
- _request_lock(r, lkb);
- if (is_master(r))
- confirm_master(r, 0);
- unlock_rsb(r);
- put_rsb(r);
- break;
-
- case DLM_MSG_REQUEST:
- hold_rsb(r);
- lock_rsb(r);
- _request_lock(r, lkb);
- if (is_master(r))
- confirm_master(r, 0);
- unlock_rsb(r);
- put_rsb(r);
- break;
-
- case DLM_MSG_CONVERT:
- hold_rsb(r);
- lock_rsb(r);
- _convert_lock(r, lkb);
- unlock_rsb(r);
- put_rsb(r);
- break;
-
- default:
- log_error(ls, "recover_waiters_post type %d", mstype);
+ /* At this point we assume that we won't get a reply to any
+ previous op or overlap op on this lock. First, do a big
+ remove_from_waiters() for all previous ops. */
+
+ lkb->lkb_flags &= ~DLM_IFL_RESEND;
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;
+ lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;
+ lkb->lkb_wait_type = 0;
+ lkb->lkb_wait_count = 0;
+ mutex_lock(&ls->ls_waiters_mutex);
+ list_del_init(&lkb->lkb_wait_reply);
+ mutex_unlock(&ls->ls_waiters_mutex);
+ unhold_lkb(lkb); /* for waiters list */
+
+ if (oc || ou) {
+ /* do an unlock or cancel instead of resending */
+ switch (mstype) {
+ case DLM_MSG_LOOKUP:
+ case DLM_MSG_REQUEST:
+ queue_cast(r, lkb, ou ? -DLM_EUNLOCK :
+ -DLM_ECANCEL);
+ unhold_lkb(lkb); /* undoes create_lkb() */
+ break;
+ case DLM_MSG_CONVERT:
+ if (oc) {
+ queue_cast(r, lkb, -DLM_ECANCEL);
+ } else {
+ lkb->lkb_exflags |= DLM_LKF_FORCEUNLOCK;
+ _unlock_lock(r, lkb);
+ }
+ break;
+ default:
+ err = 1;
+ }
+ } else {
+ switch (mstype) {
+ case DLM_MSG_LOOKUP:
+ case DLM_MSG_REQUEST:
+ _request_lock(r, lkb);
+ if (is_master(r))
+ confirm_master(r, 0);
+ break;
+ case DLM_MSG_CONVERT:
+ _convert_lock(r, lkb);
+ break;
+ default:
+ err = 1;
+ }
}
+
+ if (err)
+ log_error(ls, "recover_waiters_post %x %d %x %d %d",
+ lkb->lkb_id, mstype, lkb->lkb_flags, oc, ou);
+ unlock_rsb(r);
+ put_rsb(r);
+ dlm_put_lkb(lkb);
}

return error;
@@ -3684,7 +3990,7 @@ int dlm_user_request(struct dlm_ls *ls, struct
dlm_user_args *ua,

/* add this new lkb to the per-process list of locks */
spin_lock(&ua->proc->locks_spin);
- kref_get(&lkb->lkb_ref);
+ hold_lkb(lkb);
list_add_tail(&lkb->lkb_ownqueue, &ua->proc->locks);
spin_unlock(&ua->proc->locks_spin);
out:
@@ -3774,6 +4080,9 @@ int dlm_user_unlock(struct dlm_ls *ls, struct
dlm_user_args *ua_tmp,

if (error == -DLM_EUNLOCK)
error = 0;
+ /* from validate_unlock_args() */
+ if (error == -EBUSY && (flags & DLM_LKF_FORCEUNLOCK))
+ error = 0;
if (error)
goto out_put;

@@ -3786,6 +4095,7 @@ int dlm_user_unlock(struct dlm_ls *ls, struct
dlm_user_args *ua_tmp,
dlm_put_lkb(lkb);
out:
unlock_recovery(ls);
+ kfree(ua_tmp);
return error;
}

@@ -3815,33 +4125,37 @@ int dlm_user_cancel(struct dlm_ls *ls, struct
dlm_user_args *ua_tmp,

if (error == -DLM_ECANCEL)
error = 0;
- if (error)
- goto out_put;
-
- /* this lkb was removed from the WAITING queue */
- if (lkb->lkb_grmode == DLM_LOCK_IV) {
- spin_lock(&ua->proc->locks_spin);
- list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
- spin_unlock(&ua->proc->locks_spin);
- }
+ /* from validate_unlock_args() */
+ if (error == -EBUSY)
+ error = 0;
out_put:
dlm_put_lkb(lkb);
out:
unlock_recovery(ls);
+ kfree(ua_tmp);
return error;
}

+/* lkb's that are removed from the waiters list by revert are just left
on the
+ orphans list with the granted orphan locks, to be freed by purge */
+
static int orphan_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
{
struct dlm_user_args *ua = (struct dlm_user_args *)lkb->lkb_astparam;
+ struct dlm_args args;
+ int error;

- if (ua->lksb.sb_lvbptr)
- kfree(ua->lksb.sb_lvbptr);
- kfree(ua);
- lkb->lkb_astparam = (long)NULL;
+ hold_lkb(lkb);
+ mutex_lock(&ls->ls_orphans_mutex);
+ list_add_tail(&lkb->lkb_ownqueue, &ls->ls_orphans);
+ mutex_unlock(&ls->ls_orphans_mutex);

- /* TODO: propogate to master if needed */
- return 0;
+ set_unlock_args(0, ua, &args);
+
+ error = cancel_lock(ls, lkb, &args);
+ if (error == -DLM_ECANCEL)
+ error = 0;
+ return error;
}

/* The force flag allows the unlock to go ahead even if the lkb isn't
granted.
@@ -3853,10 +4167,6 @@ static int unlock_proc_lock(struct dlm_ls *ls,
struct dlm_lkb *lkb)
struct dlm_args args;
int error;

- /* FIXME: we need to handle the case where the lkb is in limbo
- while the rsb is being looked up, currently we assert in
- _unlock_lock/is_remote because rsb nodeid is -1. */
-
set_unlock_args(DLM_LKF_FORCEUNLOCK, ua, &args);

error = unlock_lock(ls, lkb, &args);
@@ -3865,6 +4175,31 @@ static int unlock_proc_lock(struct dlm_ls *ls,
struct dlm_lkb *lkb)
return error;
}

+/* We have to release clear_proc_locks mutex before calling
unlock_proc_lock()
+ (which does lock_rsb) due to deadlock with receiving a message that
does
+ lock_rsb followed by dlm_user_add_ast() */
+
+static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
+ struct dlm_user_proc *proc)
+{
+ struct dlm_lkb *lkb = NULL;
+
+ mutex_lock(&ls->ls_clear_proc_locks);
+ if (list_empty(&proc->locks))
+ goto out;
+
+ lkb = list_entry(proc->locks.next, struct dlm_lkb, lkb_ownqueue);
+ list_del_init(&lkb->lkb_ownqueue);
+
+ if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
+ lkb->lkb_flags |= DLM_IFL_ORPHAN;
+ else
+ lkb->lkb_flags |= DLM_IFL_DEAD;
+ out:
+ mutex_unlock(&ls->ls_clear_proc_locks);
+ return lkb;
+}
+
/* The ls_clear_proc_locks mutex protects against dlm_user_add_asts()
which
1) references lkb->ua which we free here and 2) adds lkbs to
proc->asts,
which we clear here. */
@@ -3880,18 +4215,15 @@ void dlm_clear_proc_locks(struct dlm_ls *ls,
struct dlm_user_proc *proc)
struct dlm_lkb *lkb, *safe;

lock_recovery(ls);
- mutex_lock(&ls->ls_clear_proc_locks);

- list_for_each_entry_safe(lkb, safe, &proc->locks, lkb_ownqueue) {
- list_del_init(&lkb->lkb_ownqueue);
-
- if (lkb->lkb_exflags & DLM_LKF_PERSISTENT) {
- lkb->lkb_flags |= DLM_IFL_ORPHAN;
+ while (1) {
+ lkb = del_proc_lock(ls, proc);
+ if (!lkb)
+ break;
+ if (lkb->lkb_exflags & DLM_LKF_PERSISTENT)
orphan_proc_lock(ls, lkb);
- } else {
- lkb->lkb_flags |= DLM_IFL_DEAD;
+ else
unlock_proc_lock(ls, lkb);
- }

/* this removes the reference for the proc->locks list
added by dlm_user_request, it may result in the lkb
@@ -3900,6 +4232,8 @@ void dlm_clear_proc_locks(struct dlm_ls *ls,
struct dlm_user_proc *proc)
dlm_put_lkb(lkb);
}

+ mutex_lock(&ls->ls_clear_proc_locks);
+
/* in-progress unlocks */
list_for_each_entry_safe(lkb, safe, &proc->unlocking, lkb_ownqueue) {
list_del_init(&lkb->lkb_ownqueue);
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index f40817b..f607ca2 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -2,7 +2,7 @@

*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights
reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2007 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
@@ -459,6 +459,8 @@ static int new_lockspace(char *name, int namelen,
void **lockspace,

INIT_LIST_HEAD(&ls->ls_waiters);
mutex_init(&ls->ls_waiters_mutex);
+ INIT_LIST_HEAD(&ls->ls_orphans);
+ mutex_init(&ls->ls_orphans_mutex);

INIT_LIST_HEAD(&ls->ls_nodes);
INIT_LIST_HEAD(&ls->ls_nodes_gone);
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 27a75ce..c978c67 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2006-2007 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
@@ -128,35 +128,30 @@ static void compat_output(struct dlm_lock_result
*res,
}
#endif

+/* we could possibly check if the cancel of an orphan has resulted in
the lkb
+ being removed and then remove that lkb from the orphans list and
free it */

void dlm_user_add_ast(struct dlm_lkb *lkb, int type)
{
struct dlm_ls *ls;
struct dlm_user_args *ua;
struct dlm_user_proc *proc;
- int remove_ownqueue = 0;
+ int eol = 0, ast_type;

- /* dlm_clear_proc_locks() sets ORPHAN/DEAD flag on each
- lkb before dealing with it. We need to check this
- flag before taking ls_clear_proc_locks mutex because if
- it's set, dlm_clear_proc_locks() holds the mutex. */
-
- if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) {
- /* log_print("user_add_ast skip1 %x", lkb->lkb_flags); */
+ if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
return;
- }

ls = lkb->lkb_resource->res_ls;
mutex_lock(&ls->ls_clear_proc_locks);

/* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed
- lkb->ua so we can't try to use it. */
+ lkb->ua so we can't try to use it. This second check is necessary
+ for cases where a completion ast is received for an operation that
+ began before clear_proc_locks did its cancel/unlock. */

- if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) {
- /* log_print("user_add_ast skip2 %x", lkb->lkb_flags); */
+ if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
goto out;
- }

DLM_ASSERT(lkb->lkb_astparam, dlm_print_lkb(lkb););
ua = (struct dlm_user_args *)lkb->lkb_astparam;
@@ -166,28 +161,42 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int
type)
goto out;

spin_lock(&proc->asts_spin);
- if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) {
+
+ ast_type = lkb->lkb_ast_type;
+ lkb->lkb_ast_type |= type;
+
+ if (!ast_type) {
kref_get(&lkb->lkb_ref);
list_add_tail(&lkb->lkb_astqueue, &proc->asts);
- lkb->lkb_ast_type |= type;
wake_up_interruptible(&proc->wait);
}
-
- /* noqueue requests that fail may need to be removed from the
- proc's locks list, there should be a better way of detecting
- this situation than checking all these things... */
-
- if (type == AST_COMP && lkb->lkb_grmode == DLM_LOCK_IV &&
- ua->lksb.sb_status == -EAGAIN && !list_empty(&lkb->lkb_ownqueue))
- remove_ownqueue = 1;
-
- /* unlocks or cancels of waiting requests need to be removed from the
- proc's unlocking list, again there must be a better way... */
-
- if (ua->lksb.sb_status == -DLM_EUNLOCK ||
+ if (type == AST_COMP && (ast_type & AST_COMP))
+ log_debug(ls, "ast overlap %x status %x %x",
+ lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags);
+
+ /* Figure out if this lock is at the end of its life and no longer
+ available for the application to use. The lkb still exists until
+ the final ast is read. A lock becomes EOL in three situations:
+ 1. a noqueue request fails with EAGAIN
+ 2. an unlock completes with EUNLOCK
+ 3. a cancel of a waiting request completes with ECANCEL
+ An EOL lock needs to be removed from the process's list of locks.
+ And we can't allow any new operation on an EOL lock. This is
+ not related to the lifetime of the lkb struct which is managed
+ entirely by refcount. */
+
+ if (type == AST_COMP &&
+ lkb->lkb_grmode == DLM_LOCK_IV &&
+ ua->lksb.sb_status == -EAGAIN)
+ eol = 1;
+ else if (ua->lksb.sb_status == -DLM_EUNLOCK ||
(ua->lksb.sb_status == -DLM_ECANCEL &&
lkb->lkb_grmode == DLM_LOCK_IV))
- remove_ownqueue = 1;
+ eol = 1;
+ if (eol) {
+ lkb->lkb_ast_type &= ~AST_BAST;
+ lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
+ }

/* We want to copy the lvb to userspace when the completion
ast is read if the status is 0, the lock has an lvb and
@@ -204,11 +213,13 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int
type)

spin_unlock(&proc->asts_spin);

- if (remove_ownqueue) {
+ if (eol) {
spin_lock(&ua->proc->locks_spin);
- list_del_init(&lkb->lkb_ownqueue);
+ if (!list_empty(&lkb->lkb_ownqueue)) {
+ list_del_init(&lkb->lkb_ownqueue);
+ dlm_put_lkb(lkb);
+ }
spin_unlock(&ua->proc->locks_spin);
- dlm_put_lkb(lkb);
}
out:
mutex_unlock(&ls->ls_clear_proc_locks);
--
1.5.1.2