gfs2: make gfs2_holder.gh_owner_pid be a struct pid *

The gl_owner_pid field is used to get the holder task by its pid and check
whether the current is a holder, so make it in a proper manner, i.e.  via the
struct pid * manipulations.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/gfs2/glock.c

@@ -399,7 +399,7 @@ void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
 	INIT_LIST_HEAD(&gh->gh_list);
 	gh->gh_gl = gl;
 	gh->gh_ip = (unsigned long)__builtin_return_address(0);
-	gh->gh_owner_pid = current->pid;
+	gh->gh_owner_pid = get_pid(task_pid(current));
 	gh->gh_state = state;
 	gh->gh_flags = flags;
 	gh->gh_error = 0;
@@ -433,6 +433,7 @@ void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *
 
 void gfs2_holder_uninit(struct gfs2_holder *gh)
 {
+	put_pid(gh->gh_owner_pid);
 	gfs2_glock_put(gh->gh_gl);
 	gh->gh_gl = NULL;
 	gh->gh_ip = 0;
@@ -1045,7 +1046,7 @@ static int glock_wait_internal(struct gfs2_holder *gh)
 }
 
 static inline struct gfs2_holder *
-find_holder_by_owner(struct list_head *head, pid_t pid)
+find_holder_by_owner(struct list_head *head, struct pid *pid)
 {
 	struct gfs2_holder *gh;
 
@@ -1082,7 +1083,7 @@ static void add_to_queue(struct gfs2_holder *gh)
 	struct gfs2_glock *gl = gh->gh_gl;
 	struct gfs2_holder *existing;
 
-	BUG_ON(!gh->gh_owner_pid);
+	BUG_ON(gh->gh_owner_pid == NULL);
 	if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
 		BUG();
 
@@ -1092,12 +1093,14 @@ static void add_to_queue(struct gfs2_holder *gh)
 		if (existing) {
 			print_symbol(KERN_WARNING "original: %s\n", 
 				     existing->gh_ip);
-			printk(KERN_INFO "pid : %d\n", existing->gh_owner_pid);
+			printk(KERN_INFO "pid : %d\n",
+					pid_nr(existing->gh_owner_pid));
 			printk(KERN_INFO "lock type : %d lock state : %d\n",
 			       existing->gh_gl->gl_name.ln_type, 
 			       existing->gh_gl->gl_state);
 			print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
-			printk(KERN_INFO "pid : %d\n", gh->gh_owner_pid);
+			printk(KERN_INFO "pid : %d\n",
+					pid_nr(gh->gh_owner_pid));
 			printk(KERN_INFO "lock type : %d lock state : %d\n",
 			       gl->gl_name.ln_type, gl->gl_state);
 			BUG();
@@ -1798,8 +1801,9 @@ static int dump_holder(struct glock_iter *gi, char *str,
 
 	print_dbg(gi, "  %s\n", str);
 	if (gh->gh_owner_pid) {
-		print_dbg(gi, "    owner = %ld ", (long)gh->gh_owner_pid);
-		gh_owner = find_task_by_pid(gh->gh_owner_pid);
+		print_dbg(gi, "    owner = %ld ",
+				(long)pid_nr(gh->gh_owner_pid));
+		gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
 		if (gh_owner)
 			print_dbg(gi, "(%s)\n", gh_owner->comm);
 		else

fs/gfs2/glock.h

@@ -36,11 +36,13 @@ static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
 {
 	struct gfs2_holder *gh;
 	int locked = 0;
+	struct pid *pid;
 
 	/* Look in glock's list of holders for one with current task as owner */
 	spin_lock(&gl->gl_spin);
+	pid = task_pid(current);
 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
-		if (gh->gh_owner_pid == current->pid) {
+		if (gh->gh_owner_pid == pid) {
 			locked = 1;
 			break;
 		}

fs/gfs2/incore.h

@@ -151,7 +151,7 @@ struct gfs2_holder {
 	struct list_head gh_list;
 
 	struct gfs2_glock *gh_gl;
-	pid_t gh_owner_pid;
+	struct pid *gh_owner_pid;
 	unsigned int gh_state;
 	unsigned gh_flags;