--- block/blk-settings.c

+++ block/blk-settings.c

@@ -103,7 +103,7 @@ void blk_set_default_limits(struct queue

lim->alignment_offset = 0;

lim->io_opt = 0;

lim->misaligned = 0;

- lim->cluster = 1;

+ lim->no_cluster = 0;

}

EXPORT_SYMBOL(blk_set_default_limits);

@@ -477,6 +477,15 @@ EXPORT_SYMBOL(blk_queue_io_opt);

void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)

{

blk_stack_limits(&t->limits, &b->limits, 0);

+

+ if (!t->queue_lock)

+ WARN_ON_ONCE(1);

+ else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {

+ unsigned long flags;

+ spin_lock_irqsave(t->queue_lock, flags);

+ queue_flag_clear(QUEUE_FLAG_CLUSTER, t);

+ spin_unlock_irqrestore(t->queue_lock, flags);

+ }

}

EXPORT_SYMBOL(blk_queue_stack_limits);

@@ -552,7 +561,7 @@ int blk_stack_limits(struct queue_limits

t->io_min = max(t->io_min, b->io_min);

t->io_opt = lcm(t->io_opt, b->io_opt);

- t->cluster &= b->cluster;

+ t->no_cluster |= b->no_cluster;

/* Physical block size a multiple of the logical block size? */

if (t->physical_block_size & (t->logical_block_size - 1)) {

@@ -643,6 +652,17 @@ void disk_stack_limits(struct gendisk *d

printk(KERN_NOTICE "%s: Warning: Device %s is misaligned\n",

top, bottom);

}

+

+ if (!t->queue_lock)

+ WARN_ON_ONCE(1);

+ else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {

+ unsigned long flags;

+

+ spin_lock_irqsave(t->queue_lock, flags);

+ if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))

+ queue_flag_clear(QUEUE_FLAG_CLUSTER, t);

+ spin_unlock_irqrestore(t->queue_lock, flags);

+ }

}

EXPORT_SYMBOL(disk_stack_limits);