Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | [PATCH] Module Alias back compat code | Date | Fri, 19 Dec 2003 14:08:47 +1100 |
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The provides backwards compat for old char and block aliases.
MODULE_ALIAS_BLOCK() and MODULE_ALIAS_CHAR() define aliases of form "XXX-<major>-<minor>", so we should probe for modules using this form. Unfortunately in 2.4, block aliases were "XXX-<major>" and char aliases were of both forms.
Ideally, all modules would now be using MODULE_ALIAS() macros to define their aliases, and the old configuration files wouldn't matter as much. Unfortunately, this hasn't happened, so we make request_module() return the exit status of modprobe, and then do fallback when probing for char and block devices.
Please apply. Rusty.
Name: Backwards Compatibility For Old block and char Aliases Author: Rusty Russell Status: Tested on 2.6.0
D: MODULE_ALIAS_BLOCK() and MODULE_ALIAS_CHAR() define aliases of form D: "XXX-<major>-<minor>", so we should probe for modules using this D: form. Unfortunately in 2.4, block aliases were "XXX-<major>" and D: char aliases were of both forms. D: D: Ideally, all modules would now be using MODULE_ALIAS() macros to D: define their aliases, and the old configuration files wouldn't D: matter as much. Unfortunately, this hasn't happened, so we make D: request_module() return the exit status of modprobe, and then D: do fallback when probing for char and block devices.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1494-linux-2.6.0/drivers/block/genhd.c .1494-linux-2.6.0.updated/drivers/block/genhd.c --- .1494-linux-2.6.0/drivers/block/genhd.c 2003-10-09 18:02:51.000000000 +1000 +++ .1494-linux-2.6.0.updated/drivers/block/genhd.c 2003-12-19 13:40:15.000000000 +1100 @@ -296,7 +296,9 @@ extern int blk_dev_init(void); static struct kobject *base_probe(dev_t dev, int *part, void *data) { - request_module("block-major-%d", MAJOR(dev)); + if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0) + /* Make old-style 2.4 aliases work */ + request_module("block-major-%d", MAJOR(dev)); return NULL; } diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1494-linux-2.6.0/fs/char_dev.c .1494-linux-2.6.0.updated/fs/char_dev.c --- .1494-linux-2.6.0/fs/char_dev.c 2003-11-24 15:42:32.000000000 +1100 +++ .1494-linux-2.6.0.updated/fs/char_dev.c 2003-12-19 13:40:23.000000000 +1100 @@ -434,7 +434,9 @@ void cdev_init(struct cdev *cdev, struct static struct kobject *base_probe(dev_t dev, int *part, void *data) { - request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)); + if (request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0) + /* Make old-style 2.4 aliases work */ + request_module("char-major-%d", MAJOR(dev)); return NULL; } diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1494-linux-2.6.0/include/linux/kmod.h .1494-linux-2.6.0.updated/include/linux/kmod.h --- .1494-linux-2.6.0/include/linux/kmod.h 2003-09-22 10:28:12.000000000 +1000 +++ .1494-linux-2.6.0.updated/include/linux/kmod.h 2003-12-19 13:26:50.000000000 +1100 @@ -24,6 +24,8 @@ #include <linux/compiler.h> #ifdef CONFIG_KMOD +/* modprobe exit status on success, -ve on error. Return value + * usually useless though. */ extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); #else static inline int request_module(const char * name, ...) { return -ENOSYS; } diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1494-linux-2.6.0/kernel/kmod.c .1494-linux-2.6.0.updated/kernel/kmod.c --- .1494-linux-2.6.0/kernel/kmod.c 2003-10-26 14:52:50.000000000 +1100 +++ .1494-linux-2.6.0.updated/kernel/kmod.c 2003-12-19 13:25:48.000000000 +1100 @@ -182,16 +182,21 @@ static int wait_for_helper(void *data) { struct subprocess_info *sub_info = data; pid_t pid; + struct k_sigaction sa; + + /* Install a handler: if SIGCLD isn't handled sys_wait4 won't + * populate the status, but will return -ECHILD. */ + sa.sa.sa_handler = SIG_IGN; + sa.sa.sa_flags = 0; + siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); + do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); + allow_signal(SIGCHLD); - sub_info->retval = 0; pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD); if (pid < 0) sub_info->retval = pid; else - /* We don't have a SIGCHLD signal handler, so this - * always returns -ECHILD, but the important thing is - * that it blocks. */ - sys_wait4(pid, NULL, 0, NULL); + sys_wait4(pid, &sub_info->retval, 0, NULL); complete(sub_info->complete); return 0; -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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