Joseph Qi
2014-Apr-03 12:45 UTC
[Ocfs2-devel] [PATCH] ocfs2: retry once dlm_dispatch_assert_master failed with ENOMEM
Once dlm_dispatch_assert_master failed in dlm_master_requery_handler,
the only reason is ENOMEM. So just retry it instead of BUG().
Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
---
fs/ocfs2/dlm/dlmrecovery.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 7035af0..f772d64 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1685,6 +1685,7 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32
len, void *data,
hash = dlm_lockid_hash(req->name, req->namelen);
+retry:
spin_lock(&dlm->spinlock);
res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
if (res) {
@@ -1693,10 +1694,14 @@ int dlm_master_requery_handler(struct o2net_msg *msg,
u32 len, void *data,
if (master == dlm->node_num) {
int ret = dlm_dispatch_assert_master(dlm, res,
0, 0, flags);
+ /* ENOMEM returns, just retry */
if (ret < 0) {
- mlog_errno(-ENOMEM);
- /* retry!? */
- BUG();
+ spin_unlock(&res->spinlock);
+ dlm_lockres_put(res);
+ spin_unlock(&dlm->spinlock);
+ mlog_errno(ret);
+ msleep(50);
+ goto retry;
}
} else /* put.. incase we are not the master */
dlm_lockres_put(res);
--
1.8.4.3
Wengang
2014-Apr-04 01:26 UTC
[Ocfs2-devel] [PATCH] ocfs2: retry once dlm_dispatch_assert_master failed with ENOMEM
O2net is using a single threaded work queue to process network requests. Blocking in a handler would block whole network processing. As you see, the memory allocation is with GFP_NOFS, if the first try failed, the following retries may still fail. Thus it could block a while which is not good. How about to limit the retries, say, 3 or 5 times. If it still failed to get memory, return an error to peer and peer decides to retry or give up. thanks, wengang ? 2014?04?03? 20:45, Joseph Qi ??:> Once dlm_dispatch_assert_master failed in dlm_master_requery_handler, > the only reason is ENOMEM. So just retry it instead of BUG(). > > Signed-off-by: Joseph Qi <joseph.qi at huawei.com> > --- > fs/ocfs2/dlm/dlmrecovery.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c > index 7035af0..f772d64 100644 > --- a/fs/ocfs2/dlm/dlmrecovery.c > +++ b/fs/ocfs2/dlm/dlmrecovery.c > @@ -1685,6 +1685,7 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data, > > hash = dlm_lockid_hash(req->name, req->namelen); > > +retry: > spin_lock(&dlm->spinlock); > res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash); > if (res) { > @@ -1693,10 +1694,14 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data, > if (master == dlm->node_num) { > int ret = dlm_dispatch_assert_master(dlm, res, > 0, 0, flags); > + /* ENOMEM returns, just retry */ > if (ret < 0) { > - mlog_errno(-ENOMEM); > - /* retry!? */ > - BUG(); > + spin_unlock(&res->spinlock); > + dlm_lockres_put(res); > + spin_unlock(&dlm->spinlock); > + mlog_errno(ret); > + msleep(50); > + goto retry; > } > } else /* put.. incase we are not the master */ > dlm_lockres_put(res);