Commit b8da9b10 authored by Luo Longjun's avatar Luo Longjun Committed by Jeff Layton
Browse files

fs/locks: print full locks information 



Commit fd7732e0 ("fs/locks: create a tree of dependent requests.")
has put blocked locks into a tree.

So, with a for loop, we can't check all locks information.

To solve this problem, we should traverse the tree.

Signed-off-by: default avatarLuo Longjun <luolongjun@huawei.com>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
parent a38fd874

fs/locks.c

+56 −9
Original line number Diff line number Diff line
@@ -2828,7 +2828,7 @@ struct locks_iterator { 
};



static void lock_get_status(struct seq_file *f, struct file_lock *fl,

			    loff_t id, char *pfx)

			    loff_t id, char *pfx, int repeat)

{

	struct inode *inode = NULL;

	unsigned int fl_pid;
@@ -2844,7 +2844,11 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, 
	if (fl->fl_file != NULL)

		inode = locks_inode(fl->fl_file);



	seq_printf(f, "%lld:%s ", id, pfx);

	seq_printf(f, "%lld: ", id);



	if (repeat)

		seq_printf(f, "%*s", repeat - 1 + (int)strlen(pfx), pfx);



	if (IS_POSIX(fl)) {

		if (fl->fl_flags & FL_ACCESS)

			seq_puts(f, "ACCESS");
@@ -2906,21 +2910,64 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, 
	}

}



static struct file_lock *get_next_blocked_member(struct file_lock *node)

{

	struct file_lock *tmp;



	/* NULL node or root node */

	if (node == NULL || node->fl_blocker == NULL)

		return NULL;



	/* Next member in the linked list could be itself */

	tmp = list_next_entry(node, fl_blocked_member);

	if (list_entry_is_head(tmp, &node->fl_blocker->fl_blocked_requests, fl_blocked_member)

		|| tmp == node) {

		return NULL;

	}



	return tmp;

}



static int locks_show(struct seq_file *f, void *v)

{

	struct locks_iterator *iter = f->private;

	struct file_lock *fl, *bfl;

	struct file_lock *cur, *tmp;

	struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb);

	int level = 0;



	fl = hlist_entry(v, struct file_lock, fl_link);

	cur = hlist_entry(v, struct file_lock, fl_link);



	if (locks_translate_pid(fl, proc_pidns) == 0)

	if (locks_translate_pid(cur, proc_pidns) == 0)

		return 0;



	lock_get_status(f, fl, iter->li_pos, "");

	/* View this crossed linked list as a binary tree, the first member of fl_blocked_requests

	 * is the left child of current node, the next silibing in fl_blocked_member is the

	 * right child, we can alse get the parent of current node from fl_blocker, so this

	 * question becomes traversal of a binary tree

	 */

	while (cur != NULL) {

		if (level)

			lock_get_status(f, cur, iter->li_pos, "-> ", level);

		else

			lock_get_status(f, cur, iter->li_pos, "", level);



	list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member)

		lock_get_status(f, bfl, iter->li_pos, " ->");

		if (!list_empty(&cur->fl_blocked_requests)) {

			/* Turn left */

			cur = list_first_entry_or_null(&cur->fl_blocked_requests,

				struct file_lock, fl_blocked_member);

			level++;

		} else {

			/* Turn right */

			tmp = get_next_blocked_member(cur);

			/* Fall back to parent node */

			while (tmp == NULL && cur->fl_blocker != NULL) {

				cur = cur->fl_blocker;

				level--;

				tmp = get_next_blocked_member(cur);

			}

			cur = tmp;

		}

	}



	return 0;

}
@@ -2941,7 +2988,7 @@ static void __show_fd_locks(struct seq_file *f, 


		(*id)++;

		seq_puts(f, "lock:\t");

		lock_get_status(f, fl, *id, "");

		lock_get_status(f, fl, *id, "", 0);

	}

}