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>
This commit is contained in:
David Teigland 2012-06-25 13:48:05 -05:00
parent c503a62103
commit 96006ea6d4

View file

@ -4000,12 +4000,70 @@ static int validate_message(struct dlm_lkb *lkb, struct dlm_message *ms)
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 @@ static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)
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;