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[PATCH] md: fix some locking and module refcounting issues with md's use of sysfs

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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 <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown
2005-11-08 21:39:39 -08:00
committed by Linus Torvalds
parent 3855ad9f39
commit 96de1e663c
2 changed files with 46 additions and 46 deletions
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30
drivers/md/raid5.c
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@@ -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;
}