LIST_HEAD(super_blocks);
+EXPORT_SYMBOL_GPL(super_blocks);
+
DEFINE_SPINLOCK(sb_lock);
static char *sb_writers_name[SB_FREEZE_LEVELS] = {
total_objects = sb->s_nr_dentry_unused +
sb->s_nr_inodes_unused + fs_objects + 1;
+ if (!total_objects)
+ total_objects = 1;
if (sc->nr_to_scan) {
int dentries;
* and want to turn it into a full-blown active reference. grab_super()
* is called with sb_lock held and drops it. Returns 1 in case of
* success, 0 if we had failed (superblock contents was already dead or
- * dying when grab_super() had been called).
+ * dying when grab_super() had been called). Note that this is only
+ * called for superblocks not in rundown mode (== ones still on ->fs_supers
+ * of their type), so increment of ->s_count is OK here.
*/
static int grab_super(struct super_block *s) __releases(sb_lock)
{
- if (atomic_inc_not_zero(&s->s_active)) {
- spin_unlock(&sb_lock);
- return 1;
- }
- /* it's going away */
s->s_count++;
spin_unlock(&sb_lock);
- /* wait for it to die */
down_write(&s->s_umount);
+ if ((s->s_flags & MS_BORN) && atomic_inc_not_zero(&s->s_active)) {
+ put_super(s);
+ return 1;
+ }
up_write(&s->s_umount);
put_super(s);
return 0;
destroy_super(s);
s = NULL;
}
- down_write(&old->s_umount);
- if (unlikely(!(old->s_flags & MS_BORN))) {
- deactivate_locked_super(old);
- goto retry;
- }
return old;
}
}
if (hlist_unhashed(&sb->s_instances))
continue;
if (sb->s_bdev == bdev) {
- if (grab_super(sb)) /* drops sb_lock */
- return sb;
- else
+ if (!grab_super(sb))
goto restart;
+ up_write(&sb->s_umount);
+ return sb;
}
}
spin_unlock(&sb_lock);
smp_mb();
if (waitqueue_active(&sb->s_writers.wait))
wake_up(&sb->s_writers.wait);
+ lockdep_off();
rwsem_release(&sb->s_writers.lock_map[level-1], 1, _RET_IP_);
+ lockdep_on();
}
EXPORT_SYMBOL(__sb_end_write);
break;
}
}
+ lockdep_off();
rwsem_acquire_read(&sb->s_writers.lock_map[level-1], 0, trylock, ip);
+ lockdep_on();
}
#endif