[PATCH] md: locking fix

- fix mddev_lock() usage bugs in md_attr_show() and md_attr_store().
  [they did not anticipate the possibility of getting a signal]

- remove mddev_lock_uninterruptible() [unused]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 434ca39..d7316b8 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -279,11 +279,6 @@ static inline int mddev_lock(mddev_t * mddev)
        return mutex_lock_interruptible(&mddev->reconfig_mutex);
 }
 
-static inline void mddev_lock_uninterruptible(mddev_t * mddev)
-{
-       mutex_lock(&mddev->reconfig_mutex);
-}
-
 static inline int mddev_trylock(mddev_t * mddev)
 {
        return mutex_trylock(&mddev->reconfig_mutex);
@@ -2458,9 +2453,11 @@ md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 
        if (!entry->show)
                return -EIO;
-       mddev_lock(mddev);
-       rv = entry->show(mddev, page);
-       mddev_unlock(mddev);
+       rv = mddev_lock(mddev);
+       if (!rv) {
+               rv = entry->show(mddev, page);
+               mddev_unlock(mddev);
+       }
        return rv;
 }
 
@@ -2474,9 +2471,11 @@ md_attr_store(struct kobject *kobj, struct attribute *attr,
 
        if (!entry->store)
                return -EIO;
-       mddev_lock(mddev);
-       rv = entry->store(mddev, page, length);
-       mddev_unlock(mddev);
+       rv = mddev_lock(mddev);
+       if (!rv) {
+               rv = entry->store(mddev, page, length);
+               mddev_unlock(mddev);
+       }
        return rv;
 }
 
@@ -4341,8 +4340,9 @@ static int md_seq_show(struct seq_file *seq, void *v)
                return 0;
        }
 
-       if (mddev_lock(mddev)!=0) 
+       if (mddev_lock(mddev) < 0)
                return -EINTR;
+
        if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
                seq_printf(seq, "%s : %sactive", mdname(mddev),
                                                mddev->pers ? "" : "in");