[Fixing typo in list address]
-------- Original Message --------
Subject: [PATCH] layout-sim: layout recall callback (forgetful client)
Date: Thu, 27 Jan 2011 17:06:06 +0200
From: Benny Halevy <bhalevy@xxxxxxxxxxx>
To: linux-nfs@xxxxxxxxxxxxxxx, nfsv4@xxxxxxxx
CC: Benny Halevy <bhalevy@xxxxxxxxxxx>
Simulate cb_layoutrecall with the forget client model.
The client responds with NFS4ERR_DELAY if there are any calls it needs
to wait for before processing the callback, or if there I/Os in flight
(simulated randomally). When the layout can be returned, the client
deleted it locally and replies synchronously with NFS4ERR_NOMATCHING_LAYOUT
instead of sending layout return.
The server sends only one CB_LAYOUT_RECALL at a time and does not process
any LAYOUTGETs while waiting on it, replying with NFS4ERR_RECALLCONFLICT.
LAYOUTRETURN stateid sequencing is enforced so that only those sent after
the client processed the layout recall callback are accepted.
The layout recall "process" is completed either on NFS4ERR_RECALLCONFLICT
or on a matching LAYOUTRETURN.
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
client.c | 37 ++++++++++++++++++++++--
layout.c | 21 +++++++++----
layout.h | 18 +++++++++++-
server.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
4 files changed, 150 insertions(+), 19 deletions(-)
diff --git a/client.c b/client.c
index 61163b5..182db7b 100644
--- a/client.c
+++ b/client.c
@@ -171,6 +171,8 @@ _reprocess_queue(void)
struct msg *m;
list_for_each_entry (m, &cl_queued.list, list) {
+ if (m->type == CB_LAYOUT_RECALL)
+ continue;
if (is_next(&m->stateid, &cl_layout.stateid) ||
(m->type == LAYOUTRETURN &&
m->stateid.type == OPEN_STATEID &&
@@ -227,6 +229,36 @@ out_free:
}
static void
+cl_recv_cb_layout_recall(struct msg *m)
+{
+ if ((m->stateid.type == OPEN_STATEID &&
+ cl_layout.stateid.type != OPEN_STATEID) ||
+ (m->stateid.seq > cl_layout.stateid.seq + 1)) {
+ dprintk(1, "%s: m=%p seq=%llu cl_layout.seq=%llu: waiting\n",
+ __func__, m,
+ llu(m->stateid.seq), llu(cl_layout.stateid.seq));
+ m->status = NFS4ERR_DELAY;
+ goto out;
+ }
+
+ BUG_ON(m->stateid.seq <= cl_layout.stateid.seq);
+ if (mynrand(10) < 3) {
+ dprintk(1, "%s: m=%p: simulating delay\n", __func__, m);
+ m->status = NFS4ERR_DELAY;
+ goto out;
+ }
+
+ /* forgetful model */
+ layout_delete(&cl_layout, &m->range);
+ cl_layout.stateid = m->stateid;
+ m->status = NFS4ERR_NOMATCHING_LAYOUT;
+
+out:
+ dprintk(1, "%s: m=%p status=%d\n", __func__, m, m->status);
+ enqueue(&srv_msg_queue, m);
+}
+
+static void
_cl_recv_msg(struct msg *m)
{
switch (m->type) {
@@ -236,10 +268,9 @@ _cl_recv_msg(struct msg *m)
case LAYOUTRETURN:
cl_recv_layoutreturn(m);
break;
-#if 0
- case CB_LAYOUTRECALL:
+ case CB_LAYOUT_RECALL:
+ cl_recv_cb_layout_recall(m);
break;
-#endif
default:
BUG_ON(true);
}
diff --git a/layout.c b/layout.c
index 94870f0..c5ad99a 100644
--- a/layout.c
+++ b/layout.c
@@ -65,7 +65,7 @@ last_byte_offset(u64 start, u64 len)
* |----------------|
*/
static inline int
-lo_seg_overlapping(struct layout_range *l1, struct layout_range *l2)
+lo_seg_overlapping(const struct layout_range *l1, const struct layout_range *l2)
{
u64 start1 = l1->offset;
u64 last1 = last_byte_offset(start1, l1->length);
@@ -82,13 +82,15 @@ lo_seg_overlapping(struct layout_range *l1, struct layout_range *l2)
}
bool
-layout_delete(struct layout *lo, struct layout_range *range)
+_lookup_layout(const char *func, struct layout *lo,
+ const struct layout_range *range,
+ bool do_delete)
{
bool found = false;
struct layout_item *pos, *next;
dprintk(1, "%s: %s: offset=%llu length=%llu iomode=%d roc=%d\n",
- __func__, lo->desc,
+ func, lo->desc,
llu(range->offset), llu(range->length),
range->iomode, range->roc);
@@ -98,9 +100,12 @@ layout_delete(struct layout *lo, struct layout_range *range)
(!range->roc || pos->range.roc) &&
lo_seg_overlapping(&pos->range, range)) {
dprintk(1, "%s: found l=%p\n", __func__, pos);
- list_del(&pos->list);
- myfree(pos);
found = true;
+ if (do_delete) {
+ list_del(&pos->list);
+ myfree(pos);
+ } else
+ break;
}
}
@@ -113,8 +118,10 @@ layout_verify(struct layout *server, struct layout *client)
bool ok = true, found;
struct layout_item *cl, *sl;
- if ((client->stateid.type != server->stateid.type) ||
- (client->stateid.seq != server->stateid.seq)) {
+ if (((client->stateid.type != server->stateid.type) ||
+ (client->stateid.seq != server->stateid.seq)) &&
+ (!server->layout_recall_msg ||
+ client->stateid.seq >= server->stateid.seq)) {
dprintk(0, "%s: cl stateid=%d:%llu srv stateid=%d:%llu\n",
__func__,
client->stateid.type, llu(client->stateid.seq),
diff --git a/layout.h b/layout.h
index bafad13..895b145 100644
--- a/layout.h
+++ b/layout.h
@@ -43,15 +43,31 @@ struct stateid {
type resets to OPEN_STATEID */
};
+struct msg;
+
struct layout {
struct stateid stateid;
struct list_head segs;
char *desc;
+ struct msg *layout_recall_msg;
};
void layout_init(struct layout *, char *desc);
void layout_insert(struct layout *, struct layout_range *);
-bool layout_delete(struct layout *, struct layout_range *);
+bool _lookup_layout(const char *func, struct layout *,
+ const struct layout_range *,
+ bool do_delete);
+
+static inline bool has_layout(struct layout *lo, const struct layout_range *range)
+{
+ return _lookup_layout(__func__, lo, range, false);
+}
+
+static inline bool layout_delete(struct layout *lo, const struct layout_range *range)
+{
+ return _lookup_layout(__func__, lo, range, true);
+}
+
bool layout_verify(struct layout *server, struct layout *client);
enum msg_type {
diff --git a/server.c b/server.c
index 1bc9978..19bb85a 100644
--- a/server.c
+++ b/server.c
@@ -5,6 +5,7 @@
* See "COPYING" for more information
*/
+#include "alloc.h"
#include "client.h"
#include "debug.h"
#include "layout.h"
@@ -63,10 +64,13 @@ verify_stateid(struct msg *m)
srv_layout.stateid.seq > 100) {
/* FIXME: use an actual limit on parallelism */
return m->status = NFS4ERR_OLD_STATEID;
- } else if (m->stateid.type == LAYOUT_STATEID &&
- m->stateid.seq > srv_layout.stateid.seq)
- return m->status = NFS4ERR_BAD_STATEID;
- /* TODO: CB_LAYOUTRECALL case */
+ } else if (m->stateid.type == LAYOUT_STATEID) {
+ if (srv_layout.layout_recall_msg &&
+ m->stateid.seq < srv_layout.layout_recall_msg->stateid.seq)
+ return m->status = NFS4ERR_OLD_STATEID;
+ else if (m->stateid.seq > srv_layout.stateid.seq)
+ return m->status = NFS4ERR_BAD_STATEID;
+ }
break;
default:
BUG_ON(true);
@@ -77,8 +81,13 @@ verify_stateid(struct msg *m)
static void
srv_recv_layoutget(struct msg *m)
{
+ if (srv_layout.layout_recall_msg) {
+ m->status = NFS4ERR_RECALLCONFLICT;
+ goto out;
+ }
+
if (verify_stateid(m))
- return;
+ goto out;
/* randomize layoutget response */
m->range.length = BLOCK_SIZE + mynrand(MAX_LO_MSG_LENGTH - BLOCK_SIZE);
@@ -87,22 +96,54 @@ srv_recv_layoutget(struct msg *m)
m->range.iomode = IOMODE_RW;
srv_set_stateid(m);
m->status = NFS4_OK;
- dump_msg(m);
layout_insert(&srv_layout, &m->range);
+out:
+ dump_msg(m);
}
static void
srv_recv_layoutreturn(struct msg *m)
{
+ struct msg *lrm;
+
if (verify_stateid(m))
return;
layout_delete(&srv_layout, &m->range);
srv_set_stateid(m);
m->status = NFS4_OK;
+ lrm = srv_layout.layout_recall_msg;
+ if (lrm && m->range.iomode == lrm->range.iomode &&
+ m->range.offset == lrm->range.offset &&
+ m->range.length && lrm->range.length) {
+ srv_layout.layout_recall_msg = NULL;
+ myfree(lrm);
+ }
dump_msg(m);
}
+static void
+srv_recv_cb_layout_recall(struct msg *m)
+{
+ BUG_ON(m != srv_layout.layout_recall_msg);
+ dump_msg(m);
+ switch (m->status) {
+ case NFS4_OK:
+ case NFS4ERR_DELAY:
+ dprintk(1, "%s: m=%p: layout_recall resent\n",
+ __func__, srv_layout.layout_recall_msg);
+ enqueue(&cl_msg_queue, srv_layout.layout_recall_msg);
+ break;
+ case NFS4ERR_NOMATCHING_LAYOUT:
+ layout_delete(&cl_layout, &m->range);
+ srv_layout.layout_recall_msg = NULL;
+ myfree(m);
+ break;
+ default:
+ BUG_ON(true);
+ }
+}
+
void
srv_recv_msg(void)
{
@@ -121,15 +162,51 @@ srv_recv_msg(void)
case LAYOUTRETURN:
srv_recv_layoutreturn(m);
break;
+ case CB_LAYOUT_RECALL:
+ srv_recv_cb_layout_recall(m);
+ return;
default:
BUG_ON(true);
}
enqueue(&cl_msg_queue, m);
}
+static void
+srv_recall_layout(void)
+{
+ struct msg *m;
+
+ if (srv_layout.layout_recall_msg) {
+ dprintk(1, "%s: m=%p layout_recall already in progress: status=%d\n",
+ __func__,
+ srv_layout.layout_recall_msg,
+ srv_layout.layout_recall_msg->status);
+ return;
+ }
+
+ dprintk(1, "%s\n", __func__);
+ m = myzalloc(sizeof(*m));
+ m->type = CB_LAYOUT_RECALL;
+ m->range.offset = mynrand(MAX_LO_MSG_OFFSET) & ~BLOCK_MASK;
+ m->range.length = BLOCK_SIZE + mynrand(MAX_LO_MSG_LENGTH - BLOCK_SIZE);
+ m->range.iomode = IOMODE_READ + mynrand(3);
+ /* bump server stateid.seq */
+ srv_layout.stateid.seq++;
+ m->stateid = srv_layout.stateid;
+ m->status = -1;
+ srv_layout.layout_recall_msg = m;
+ dump_msg(m);
+
+ enqueue(&cl_msg_queue, m);
+}
+
+struct rand_event srv_events[] = {
+ { 75, srv_recv_msg },
+ { 25, srv_recall_layout },
+};
+
void
srv_draw_event(void)
{
- srv_recv_msg();
+ rand_call(srv_events);
}
-
--
1.7.3.4
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