From 96de1e663cda65ba9275afb1bc007f34e5068ba1 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 8 Nov 2005 21:39:39 -0800 Subject: [PATCH] md: fix some locking and module refcounting issues with md's use of sysfs 1/ I really should be using the __ATTR macros for defining attributes, so that the .owner field get set properly, otherwise modules can be removed while sysfs files are open. This also involves some name changes of _show routines. 2/ Always lock the mddev (against reconfiguration) for all sysfs attribute access. This easily avoid certain races and is completely consistant with other interfaces (ioctl and /proc/mdstat both always lock against reconfiguration). 3/ raid5 attributes must check that the 'conf' structure actually exists (the array could have been stopped while an attribute file was open). 4/ A missing 'kfree' from when the raid5_conf_t was converted to have a kobject embedded, and then converted back again. Signed-off-by: Neil Brown Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/raid5.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 51003b008de..e2a40283e32 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1746,7 +1746,10 @@ static ssize_t raid5_show_stripe_cache_size(mddev_t *mddev, char *page) { raid5_conf_t *conf = mddev_to_conf(mddev); - return sprintf(page, "%d\n", conf->max_nr_stripes); + if (conf) + return sprintf(page, "%d\n", conf->max_nr_stripes); + else + return 0; } static ssize_t @@ -1757,6 +1760,8 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) int new; if (len >= PAGE_SIZE) return -EINVAL; + if (!conf) + return -ENODEV; new = simple_strtoul(page, &end, 10); if (!*page || (*end && *end != '\n') ) @@ -1777,23 +1782,23 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) return len; } -static struct md_sysfs_entry raid5_stripecache_size = { - .attr = {.name = "stripe_cache_size", .mode = S_IRUGO | S_IWUSR }, - .show = raid5_show_stripe_cache_size, - .store = raid5_store_stripe_cache_size, -}; +static struct md_sysfs_entry +raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, + raid5_show_stripe_cache_size, + raid5_store_stripe_cache_size); static ssize_t -raid5_show_stripe_cache_active(mddev_t *mddev, char *page) +stripe_cache_active_show(mddev_t *mddev, char *page) { raid5_conf_t *conf = mddev_to_conf(mddev); - return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); + if (conf) + return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); + else + return 0; } -static struct md_sysfs_entry raid5_stripecache_active = { - .attr = {.name = "stripe_cache_active", .mode = S_IRUGO}, - .show = raid5_show_stripe_cache_active, -}; +static struct md_sysfs_entry +raid5_stripecache_active = __ATTR_RO(stripe_cache_active); static struct attribute *raid5_attrs[] = { &raid5_stripecache_size.attr, @@ -1981,6 +1986,7 @@ static int stop(mddev_t *mddev) free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ sysfs_remove_group(&mddev->kobj, &raid5_attrs_group); + kfree(conf); mddev->private = NULL; return 0; } -- cgit v1.2.3