From 7c53e847ff5e97f033fdd31f71949807633d506b Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Thu, 24 Aug 2023 16:51:42 -0400 Subject: [PATCH] dlm: fix plock lookup when using multiple lockspaces All posix lock ops, for all lockspaces (gfs2 file systems) are sent to userspace (dlm_controld) through a single misc device. The dlm_controld daemon reads the ops from the misc device and sends them to other cluster nodes using separate, per-lockspace cluster api communication channels. The ops for a single lockspace are ordered at this level, so that the results are received in the same sequence that the requests were sent. When the results are sent back to the kernel via the misc device, they are again funneled through the single misc device for all lockspaces. When the dlm code in the kernel processes the results from the misc device, these results will be returned in the same sequence that the requests were sent, on a per-lockspace basis. A recent change in this request/reply matching code missed the "per-lockspace" check (fsid comparison) when matching request and reply, so replies could be incorrectly matched to requests from other lockspaces. Cc: stable@vger.kernel.org Reported-by: Barry Marson Fixes: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace") Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/plock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c index 00e1d802a81c..e6b4c1a21446 100644 --- a/fs/dlm/plock.c +++ b/fs/dlm/plock.c @@ -556,7 +556,8 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, op = plock_lookup_waiter(&info); } else { list_for_each_entry(iter, &recv_list, list) { - if (!iter->info.wait) { + if (!iter->info.wait && + iter->info.fsid == info.fsid) { op = iter; break; } @@ -568,8 +569,7 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, if (info.wait) WARN_ON(op->info.optype != DLM_PLOCK_OP_LOCK); else - WARN_ON(op->info.fsid != info.fsid || - op->info.number != info.number || + WARN_ON(op->info.number != info.number || op->info.owner != info.owner || op->info.optype != info.optype);