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authorJeff Dike <jdike@addtoit.com>2007-02-10 04:43:57 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-11 13:51:21 -0500
commit42d36115d25725fb551250c8f70602a12aa8dee2 (patch)
tree8adf4535d3f79c4a590100407f229e21c05a2080 /arch/um
parent4ea21cd9173a0ffa75dc74cc46d08dfc45654f29 (diff)
[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 <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/harddog_kern.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index 64ff22aa077b..94bbcb5b9227 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -44,12 +44,13 @@
44#include <linux/reboot.h> 44#include <linux/reboot.h>
45#include <linux/smp_lock.h> 45#include <linux/smp_lock.h>
46#include <linux/init.h> 46#include <linux/init.h>
47#include <linux/spinlock.h>
47#include <asm/uaccess.h> 48#include <asm/uaccess.h>
48#include "mconsole.h" 49#include "mconsole.h"
49 50
50MODULE_LICENSE("GPL"); 51MODULE_LICENSE("GPL");
51 52
52/* Locked by the BKL in harddog_open and harddog_release */ 53static DEFINE_SPINLOCK(lock);
53static int timer_alive; 54static int timer_alive;
54static int harddog_in_fd = -1; 55static int harddog_in_fd = -1;
55static int harddog_out_fd = -1; 56static int harddog_out_fd = -1;
@@ -62,12 +63,12 @@ extern int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock);
62 63
63static int harddog_open(struct inode *inode, struct file *file) 64static int harddog_open(struct inode *inode, struct file *file)
64{ 65{
65 int err; 66 int err = -EBUSY;
66 char *sock = NULL; 67 char *sock = NULL;
67 68
68 lock_kernel(); 69 spin_lock(&lock);
69 if(timer_alive) 70 if(timer_alive)
70 return -EBUSY; 71 goto err;
71#ifdef CONFIG_HARDDOG_NOWAYOUT 72#ifdef CONFIG_HARDDOG_NOWAYOUT
72 __module_get(THIS_MODULE); 73 __module_get(THIS_MODULE);
73#endif 74#endif
@@ -76,11 +77,15 @@ static int harddog_open(struct inode *inode, struct file *file)
76 sock = mconsole_notify_socket(); 77 sock = mconsole_notify_socket();
77#endif 78#endif
78 err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock); 79 err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock);
79 if(err) return(err); 80 if(err)
81 goto err;
80 82
81 timer_alive = 1; 83 timer_alive = 1;
82 unlock_kernel(); 84 spin_unlock(&lock);
83 return nonseekable_open(inode, file); 85 return nonseekable_open(inode, file);
86err:
87 spin_unlock(&lock);
88 return err;
84} 89}
85 90
86extern void stop_watchdog(int in_fd, int out_fd); 91extern void stop_watchdog(int in_fd, int out_fd);
@@ -90,14 +95,16 @@ static int harddog_release(struct inode *inode, struct file *file)
90 /* 95 /*
91 * Shut off the timer. 96 * Shut off the timer.
92 */ 97 */
93 lock_kernel(); 98
99 spin_lock(&lock);
94 100
95 stop_watchdog(harddog_in_fd, harddog_out_fd); 101 stop_watchdog(harddog_in_fd, harddog_out_fd);
96 harddog_in_fd = -1; 102 harddog_in_fd = -1;
97 harddog_out_fd = -1; 103 harddog_out_fd = -1;
98 104
99 timer_alive=0; 105 timer_alive=0;
100 unlock_kernel(); 106 spin_unlock(&lock);
107
101 return 0; 108 return 0;
102} 109}
103 110