[Ocfs2-devel] [PATCH v2 1/2] ocfs2: dlmfs: not clear USER_LOCK_ATTACHED when destroy lock - Junxiao Bi via Ocfs2-devel

From: Junxiao Bi via Ocfs2-devel <ocfs2-devel@oss.oracle.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH v2 1/2] ocfs2: dlmfs: not clear USER_LOCK_ATTACHED when destroy lock
Date: Wed, 18 May 2022 16:52:23 -0700	[thread overview]
Message-ID: <20220518235224.87100-1-junxiao.bi@oracle.com> (raw)

The following function is the only place that check USER_LOCK_ATTACHED,
this flag is set when lock request is granted through user_ast() and
only the following function will clear it.

Checking of this flag here is to make sure ocfs2_dlm_unlock is not
issued if this lock is never granted. For example, lock file is created
and then get removed, open file never happens.

Clearing the flag here is not necessary because this is the only function
that checks it, if another flow is executing user_dlm_destroy_lock(), it
will bail out at the beginning because of USER_LOCK_IN_TEARDOWN and never
check USER_LOCK_ATTACHED.
Drop the clear, so we don't need take care it for the following
error handling patch.

int user_dlm_destroy_lock(struct user_lock_res *lockres)
{
    ...

    status = 0;
    if (!(lockres->l_flags & USER_LOCK_ATTACHED)) {
        spin_unlock(&lockres->l_lock);
        goto bail;
    }

    lockres->l_flags &= ~USER_LOCK_ATTACHED;
    lockres->l_flags |= USER_LOCK_BUSY;
    spin_unlock(&lockres->l_lock);

	status = ocfs2_dlm_unlock(conn, &lockres->l_lksb, DLM_LKF_VALBLK);
    if (status) {
        user_log_dlm_error("ocfs2_dlm_unlock", status, lockres);
        goto bail;
    }
	...
}

V1 discussion with Joseph:
https://lore.kernel.org/all/7b620c53-0c45-da2c-829e-26195cbe7d4e@linux.alibaba.com/T/

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
---
 fs/ocfs2/dlmfs/userdlm.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/ocfs2/dlmfs/userdlm.c b/fs/ocfs2/dlmfs/userdlm.c
index 29f183a15798..af0be612589c 100644
--- a/fs/ocfs2/dlmfs/userdlm.c
+++ b/fs/ocfs2/dlmfs/userdlm.c
@@ -619,7 +619,6 @@ int user_dlm_destroy_lock(struct user_lock_res *lockres)
 		goto bail;
 	}
 
-	lockres->l_flags &= ~USER_LOCK_ATTACHED;
 	lockres->l_flags |= USER_LOCK_BUSY;
 	spin_unlock(&lockres->l_lock);
 
-- 
2.24.3 (Apple Git-128)


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