Commit 3e7b1919 authored by Ian Kent's avatar Ian Kent Committed by Linus Torvalds
Browse files

[PATCH] autofs4: atomic var underflow 



Fix accidental underflow of the atomic counter.

Signed-off-by: default avatarIan Kent <raven@themaw.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 871f9434

fs/autofs4/autofs_i.h

+1 −1
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ struct autofs_wait_queue { 
	pid_t tgid;

	/* This is for status reporting upon return */

	int status;

	atomic_t notified;

	atomic_t notify;

	atomic_t wait_ctr;

};

fs/autofs4/waitq.c

+4 −2
Original line number Diff line number Diff line
@@ -263,7 +263,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, 
		wq->tgid = current->tgid;

		wq->status = -EINTR; /* Status return if interrupted */

		atomic_set(&wq->wait_ctr, 2);

		atomic_set(&wq->notified, 1);

		atomic_set(&wq->notify, 1);

		mutex_unlock(&sbi->wq_mutex);

	} else {

		atomic_inc(&wq->wait_ctr);
@@ -273,9 +273,11 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, 
			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);

	}



	if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) {

	if (notify != NFY_NONE && atomic_read(&wq->notify)) {

		int type;



		atomic_dec(&wq->notify);



		if (sbi->version < 5) {

			if (notify == NFY_MOUNT)

				type = autofs_ptype_missing;