linux/fs/ocfs2/dlmfs
Junxiao Bi 0b6d14e3db ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock
The following function is the only place that checks 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 of
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/

Link: https://lkml.kernel.org/r/20220518235224.87100-1-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-25 13:05:42 -07:00
..
dlmfs.c fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
Makefile ocfs2: make local header paths relative to C files 2020-01-31 10:30:36 -08:00
userdlm.c ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock 2022-05-25 13:05:42 -07:00
userdlm.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00