dlm: fix missing dir remove
I don't know exactly how, but in some cases, a dir
record is not removed, or a new one is created when
it shouldn't be. The result is that the dir node
lookup returns a master node where the rsb does not
exist. In this case, The master node will repeatedly
return -EBADR for requests, and the lock requests will
be stuck.
Until all possible ways for this to happen can be
eliminated, a simple and effective way to recover from
this situation is for the supposed master node to send
a standard remove message to the dir node when it
receives a request for a resource it has no rsb for.
Signed-off-by: David Teigland <teigland@redhat.com>
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 04e3f15..b569507 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -4000,12 +4000,70 @@
return error;
}
+static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
+{
+ char name[DLM_RESNAME_MAXLEN + 1];
+ struct dlm_message *ms;
+ struct dlm_mhandle *mh;
+ struct dlm_rsb *r;
+ uint32_t hash, b;
+ int rv, dir_nodeid;
+
+ memset(name, 0, sizeof(name));
+ memcpy(name, ms_name, len);
+
+ hash = jhash(name, len, 0);
+ b = hash & (ls->ls_rsbtbl_size - 1);
+
+ dir_nodeid = dlm_hash2nodeid(ls, hash);
+
+ log_error(ls, "send_repeat_remove dir %d %s", dir_nodeid, name);
+
+ spin_lock(&ls->ls_rsbtbl[b].lock);
+ rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r);
+ if (!rv) {
+ spin_unlock(&ls->ls_rsbtbl[b].lock);
+ log_error(ls, "repeat_remove on keep %s", name);
+ return;
+ }
+
+ rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r);
+ if (!rv) {
+ spin_unlock(&ls->ls_rsbtbl[b].lock);
+ log_error(ls, "repeat_remove on toss %s", name);
+ return;
+ }
+
+ /* use ls->remove_name2 to avoid conflict with shrink? */
+
+ spin_lock(&ls->ls_remove_spin);
+ ls->ls_remove_len = len;
+ memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
+ spin_unlock(&ls->ls_remove_spin);
+ spin_unlock(&ls->ls_rsbtbl[b].lock);
+
+ rv = _create_message(ls, sizeof(struct dlm_message) + len,
+ dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
+ if (rv)
+ return;
+
+ memcpy(ms->m_extra, name, len);
+ ms->m_hash = hash;
+
+ send_message(mh, ms);
+
+ spin_lock(&ls->ls_remove_spin);
+ ls->ls_remove_len = 0;
+ memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
+ spin_unlock(&ls->ls_remove_spin);
+}
+
static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)
{
struct dlm_lkb *lkb;
struct dlm_rsb *r;
int from_nodeid;
- int error, namelen;
+ int error, namelen = 0;
from_nodeid = ms->m_header.h_nodeid;
@@ -4073,13 +4131,21 @@
delayed in being sent/arriving/being processed on the dir node.
Another node would repeatedly lookup up the master, and the dir
node would continue returning our nodeid until our send_remove
- took effect. */
+ took effect.
+
+ We send another remove message in case our previous send_remove
+ was lost/ignored/missed somehow. */
if (error != -ENOTBLK) {
log_limit(ls, "receive_request %x from %d %d",
ms->m_lkid, from_nodeid, error);
}
+ if (namelen && error == -EBADR) {
+ send_repeat_remove(ls, ms->m_extra, namelen);
+ msleep(1000);
+ }
+
setup_stub_lkb(ls, ms);
send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error);
return error;