Commit 3db835dd authored by fuyuanli's avatar fuyuanli Committed by Jon Mason
Browse files

ntb: Add mutex to make link_event_callback executed linearly. 



Since the CPU selected by schedule_work is uncertain, multiple link_event
callbacks may be executed at same time. For example, after peer's link is
up, it is down quickly before local link_work completed. If link_cleanup
is added to the workqueue of another CPU, then link_work and link_cleanup
may be executed at the same time. So add a mutex to prevent them from being
executed concurrently.

Signed-off-by: default avatarfuyuanli <fuyuanli@didiglobal.com>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent eb4431bf

drivers/ntb/ntb_transport.c

+7 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ 
#include <linux/slab.h>

#include <linux/types.h>

#include <linux/uaccess.h>

#include <linux/mutex.h>

#include "linux/ntb.h"

#include "linux/ntb_transport.h"
@@ -241,6 +242,9 @@ struct ntb_transport_ctx { 
	struct work_struct link_cleanup;



	struct dentry *debugfs_node_dir;



	/* Make sure workq of link event be executed serially */

	struct mutex link_event_lock;

};



enum {
@@ -1024,6 +1028,7 @@ static void ntb_transport_link_cleanup_work(struct work_struct *work) 
	struct ntb_transport_ctx *nt =

		container_of(work, struct ntb_transport_ctx, link_cleanup);



	guard(mutex)(&nt->link_event_lock);

	ntb_transport_link_cleanup(nt);

}
@@ -1047,6 +1052,8 @@ static void ntb_transport_link_work(struct work_struct *work) 
	u32 val;

	int rc = 0, i, spad;



	guard(mutex)(&nt->link_event_lock);



	/* send the local info, in the opposite order of the way we read it */



	if (nt->use_msi) {