Commit a8449f23 authored by Alexander Aring's avatar Alexander Aring Committed by David Teigland
Browse files

dlm: add __CHECKER__ for false positives 



This patch will adds #ifndef __CHECKER__ for false positives warnings
about an imbalance lock/unlock srcu handling. Which are shown by running
sparse checks:

fs/dlm/midcomms.c:1065:20: warning: context imbalance in 'dlm_midcomms_get_mhandle' - wrong count at exit

Using __CHECKER__ will tell sparse to ignore these sections.

Those imbalances are false positive because from upper layer it is
always required to call a function in sequence, e.g. if
dlm_midcomms_get_mhandle() is successful there must be a
dlm_midcomms_commit_mhandle() call afterwards.

Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 314a5540

fs/dlm/lowcomms.c

+10 −0
Original line number Diff line number Diff line
@@ -1303,6 +1303,10 @@ static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len, 
	return msg;

}



/* avoid false positive for nodes_srcu, unlock happens in

 * dlm_lowcomms_commit_msg which is a must call if success

 */

#ifndef __CHECKER__

struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,

				     char **ppc, void (*cb)(void *data),

				     void *data)
@@ -1336,6 +1340,7 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation, 
	msg->idx = idx;

	return msg;

}

#endif



static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg)

{
@@ -1362,11 +1367,16 @@ static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg) 
	return;

}



/* avoid false positive for nodes_srcu, lock was happen in

 * dlm_lowcomms_new_msg

 */

#ifndef __CHECKER__

void dlm_lowcomms_commit_msg(struct dlm_msg *msg)

{

	_dlm_lowcomms_commit_msg(msg);

	srcu_read_unlock(&connections_srcu, msg->idx);

}

#endif



void dlm_lowcomms_put_msg(struct dlm_msg *msg)

{

fs/dlm/midcomms.c

+10 −0
Original line number Diff line number Diff line
@@ -1062,6 +1062,10 @@ static struct dlm_msg *dlm_midcomms_get_msg_3_2(struct dlm_mhandle *mh, int node 
	return msg;

}



/* avoid false positive for nodes_srcu, unlock happens in

 * dlm_midcomms_commit_mhandle which is a must call if success

 */

#ifndef __CHECKER__

struct dlm_mhandle *dlm_midcomms_get_mhandle(int nodeid, int len,

					     gfp_t allocation, char **ppc)

{
@@ -1127,6 +1131,7 @@ struct dlm_mhandle *dlm_midcomms_get_mhandle(int nodeid, int len, 
	srcu_read_unlock(&nodes_srcu, idx);

	return NULL;

}

#endif



static void dlm_midcomms_commit_msg_3_2(struct dlm_mhandle *mh)

{
@@ -1136,6 +1141,10 @@ static void dlm_midcomms_commit_msg_3_2(struct dlm_mhandle *mh) 
	dlm_lowcomms_commit_msg(mh->msg);

}



/* avoid false positive for nodes_srcu, lock was happen in

 * dlm_midcomms_get_mhandle

 */

#ifndef __CHECKER__

void dlm_midcomms_commit_mhandle(struct dlm_mhandle *mh)

{

	switch (mh->node->version) {
@@ -1157,6 +1166,7 @@ void dlm_midcomms_commit_mhandle(struct dlm_mhandle *mh) 
		break;

	}

}

#endif



int dlm_midcomms_start(void)

{