From 42d36115d25725fb551250c8f70602a12aa8dee2 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Sat, 10 Feb 2007 01:43:57 -0800 Subject: [PATCH] uml: watchdog driver locking Replace BKL use with a spinlock. Also fix the control so that open doesn't return holding a lock. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/harddog_kern.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c index 64ff22aa077..94bbcb5b922 100644 --- a/arch/um/drivers/harddog_kern.c +++ b/arch/um/drivers/harddog_kern.c @@ -44,12 +44,13 @@ #include #include #include +#include #include #include "mconsole.h" MODULE_LICENSE("GPL"); -/* Locked by the BKL in harddog_open and harddog_release */ +static DEFINE_SPINLOCK(lock); static int timer_alive; static int harddog_in_fd = -1; static int harddog_out_fd = -1; @@ -62,12 +63,12 @@ extern int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock); static int harddog_open(struct inode *inode, struct file *file) { - int err; + int err = -EBUSY; char *sock = NULL; - lock_kernel(); + spin_lock(&lock); if(timer_alive) - return -EBUSY; + goto err; #ifdef CONFIG_HARDDOG_NOWAYOUT __module_get(THIS_MODULE); #endif @@ -76,11 +77,15 @@ static int harddog_open(struct inode *inode, struct file *file) sock = mconsole_notify_socket(); #endif err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock); - if(err) return(err); + if(err) + goto err; timer_alive = 1; - unlock_kernel(); + spin_unlock(&lock); return nonseekable_open(inode, file); +err: + spin_unlock(&lock); + return err; } extern void stop_watchdog(int in_fd, int out_fd); @@ -90,14 +95,16 @@ static int harddog_release(struct inode *inode, struct file *file) /* * Shut off the timer. */ - lock_kernel(); + + spin_lock(&lock); stop_watchdog(harddog_in_fd, harddog_out_fd); harddog_in_fd = -1; harddog_out_fd = -1; timer_alive=0; - unlock_kernel(); + spin_unlock(&lock); + return 0; } -- cgit