From b8831a1d2c78c03b8193ab3acf56664fa3457265 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Sat, 10 Feb 2007 01:44:17 -0800 Subject: [PATCH] [PATCH] uml: locking fixes in the ubd driver Some small locking and formatting fixes in the ubd driver. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/ubd_kern.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index d863482cdd2..da0badcd755 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -131,7 +131,6 @@ static struct block_device_operations ubd_blops = { /* Protected by ubd_lock */ static int fake_major = MAJOR_NR; - static struct gendisk *ubd_gendisk[MAX_DEV]; static struct gendisk *fake_gendisk[MAX_DEV]; @@ -142,10 +141,6 @@ static struct gendisk *fake_gendisk[MAX_DEV]; #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ .cl = 1 }) #endif - -/* Not protected - changed only in ubd_setup_common and then only to - * to enable O_SYNC. - */ static struct openflags global_openflags = OPEN_FLAGS; struct cow { @@ -197,6 +192,7 @@ struct ubd { .lock = SPIN_LOCK_UNLOCKED, \ } +/* Protected by ubd_lock */ struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; /* Only changed by fake_ide_setup which is a setup */ @@ -288,7 +284,7 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out) struct ubd *ubd_dev; struct openflags flags = global_openflags; char *backing_file; - int n, err, i; + int n, err = 0, i; if(index_out) *index_out = -1; n = *str; @@ -299,15 +295,16 @@ static int ubd_setup_common(char *str, int *index_out, char **error_out) str++; if(!strcmp(str, "sync")){ global_openflags = of_sync(global_openflags); - return 0; + goto out1; } + + err = -EINVAL; major = simple_strtoul(str, &end, 0); if((*end != '\0') || (end == str)){ *error_out = "Didn't parse major number"; - return -EINVAL; + goto out1; } - err = -EINVAL; mutex_lock(&ubd_lock); if(fake_major != MAJOR_NR){ *error_out = "Can't assign a fake major twice"; @@ -473,12 +470,6 @@ static void do_ubd_request(request_queue_t * q); /* Only changed by ubd_init, which is an initcall. */ int thread_fd = -1; -/* Changed by ubd_handler, which is serialized because interrupts only - * happen on CPU 0. - * XXX: currently unused. - */ -static int intr_count = 0; - /* call ubd_finish if you need to serialize */ static void __ubd_finish(struct request *req, int error) { @@ -518,7 +509,6 @@ static void ubd_handler(void) int n; do_ubd = 0; - intr_count++; n = os_read_file(thread_fd, &req, sizeof(req)); if(n != sizeof(req)){ printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " @@ -637,8 +627,7 @@ static int ubd_open_dev(struct ubd *ubd_dev) } static int ubd_disk_register(int major, u64 size, int unit, - struct gendisk **disk_out) - + struct gendisk **disk_out) { struct gendisk *disk; @@ -840,7 +829,7 @@ out: } /* All these are called by mconsole in process context and without - * ubd-specific locks. + * ubd-specific locks. The structure itself is const except for .list. */ static struct mc_device ubd_mc = { .list = LIST_HEAD_INIT(ubd_mc.list), @@ -863,13 +852,17 @@ static int __init ubd0_init(void) { struct ubd *ubd_dev = &ubd_devs[0]; + mutex_lock(&ubd_lock); if(ubd_dev->file == NULL) ubd_dev->file = "root_fs"; + mutex_unlock(&ubd_lock); + return(0); } __initcall(ubd0_init); +/* Used in ubd_init, which is an initcall */ static struct platform_driver ubd_driver = { .driver = { .name = DRIVER_NAME, @@ -892,12 +885,14 @@ static int __init ubd_init(void) return -1; } platform_driver_register(&ubd_driver); + mutex_lock(&ubd_lock); for (i = 0; i < MAX_DEV; i++){ err = ubd_add(i, &error); if(err) printk(KERN_ERR "Failed to initialize ubd device %d :" "%s\n", i, error); } + mutex_unlock(&ubd_lock); return 0; } @@ -1129,7 +1124,7 @@ static int ubd_ioctl(struct inode * inode, struct file * file, sizeof(ubd_id))) return(-EFAULT); return(0); - + case CDROMVOLREAD: if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) return(-EFAULT); -- 2.41.0