From 889746917193ab3007a779d65231510715b20fb6 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:14 -0400 Subject: 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 Signed-off-by: Al Viro --- fs/locks.c | 45 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 36 insertions(+), 9 deletions(-) (limited to 'fs/locks.c') diff --git a/fs/locks.c b/fs/locks.c index 1d6cb28816be..89d898bce166 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 *fl) +{ + list_add_tail(&fl->fl_link, &file_lock_list); +} + +static inline void +locks_delete_global_locks(struct file_lock *fl) +{ + list_del_init(&fl->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); -- cgit v1.2.1