linux-kernel - [PATCH v3 05/13] locks: encapsulate the fl

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1371482036-15958-6-git-send-email-jlayton@redhat.com>
Date:	Mon, 17 Jun 2013 11:13:48 -0400
From:	Jeff Layton <jlayton@...hat.com>
To:	viro@...iv.linux.org.uk, matthew@....cx, bfields@...ldses.org
Cc:	dhowells@...hat.com, sage@...tank.com, smfrench@...il.com,
	swhiteho@...hat.com, Trond.Myklebust@...app.com,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	linux-afs@...ts.infradead.org, ceph-devel@...r.kernel.org,
	linux-cifs@...r.kernel.org, samba-technical@...ts.samba.org,
	cluster-devel@...hat.com, linux-nfs@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, piastryyy@...il.com
Subject: [PATCH v3 05/13] locks: encapsulate the fl_link list handling

Move the fl_link list handling routines into a separate set of helpers.
Also ensure that locks and requests are always put on global lists
last (after fully initializing them) and are taken off before unintializing
them.

Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
 fs/locks.c |   45 ++++++++++++++++++++++++++++++++++++---------
 1 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index c186649..c0e613f 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -153,13 +153,15 @@ int lease_break_time = 45;
 #define for_each_lock(inode, lockp) \
 	for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next)
 
+/* The global file_lock_list is only used for displaying /proc/locks. */
 static LIST_HEAD(file_lock_list);
+
+/* The blocked_list is used to find POSIX lock loops for deadlock detection. */
 static LIST_HEAD(blocked_list);
+
+/* Protects the two list heads above, plus the inode->i_flock list */
 static DEFINE_SPINLOCK(file_lock_lock);
 
-/*
- * Protects the two list heads above, plus the inode->i_flock list
- */
 void lock_flocks(void)
 {
 	spin_lock(&file_lock_lock);
@@ -484,13 +486,37 @@ static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
 	return fl1->fl_owner == fl2->fl_owner;
 }
 
+static inline void
+locks_insert_global_locks(struct file_lock *waiter)
+{
+	list_add_tail(&waiter->fl_link, &file_lock_list);
+}
+
+static inline void
+locks_delete_global_locks(struct file_lock *waiter)
+{
+	list_del_init(&waiter->fl_link);
+}
+
+static inline void
+locks_insert_global_blocked(struct file_lock *waiter)
+{
+	list_add(&waiter->fl_link, &blocked_list);
+}
+
+static inline void
+locks_delete_global_blocked(struct file_lock *waiter)
+{
+	list_del_init(&waiter->fl_link);
+}
+
 /* Remove waiter from blocker's block list.
  * When blocker ends up pointing to itself then the list is empty.
  */
 static void __locks_delete_block(struct file_lock *waiter)
 {
+	locks_delete_global_blocked(waiter);
 	list_del_init(&waiter->fl_block);
-	list_del_init(&waiter->fl_link);
 	waiter->fl_next = NULL;
 }
 
@@ -512,10 +538,10 @@ static void locks_insert_block(struct file_lock *blocker,
 			       struct file_lock *waiter)
 {
 	BUG_ON(!list_empty(&waiter->fl_block));
-	list_add_tail(&waiter->fl_block, &blocker->fl_block);
 	waiter->fl_next = blocker;
+	list_add_tail(&waiter->fl_block, &blocker->fl_block);
 	if (IS_POSIX(blocker))
-		list_add(&waiter->fl_link, &blocked_list);
+		locks_insert_global_blocked(request);
 }
 
 /*
@@ -543,13 +569,13 @@ static void locks_wake_up_blocks(struct file_lock *blocker)
  */
 static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
 {
-	list_add(&fl->fl_link, &file_lock_list);
-
 	fl->fl_nspid = get_pid(task_tgid(current));
 
 	/* insert into file's list */
 	fl->fl_next = *pos;
 	*pos = fl;
+
+	locks_insert_global_locks(fl);
 }
 
 /*
@@ -562,9 +588,10 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
 {
 	struct file_lock *fl = *thisfl_p;
 
+	locks_delete_global_locks(fl);
+
 	*thisfl_p = fl->fl_next;
 	fl->fl_next = NULL;
-	list_del_init(&fl->fl_link);
 
 	if (fl->fl_nspid) {
 		put_pid(fl->fl_nspid);
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/