check in the original version of dde linux26.

3 files changed, 3540 insertions, 0 deletions

diff --git a/libdde_linux26/lib/src/block/.svn/text-base/blk-core.c.svn-base b/libdde_linux26/lib/src/block/.svn/text-base/blk-core.c.svn-base
new file mode 100644
index 00000000..92241e50
--- /dev/null
+++ b/libdde_linux26/lib/src/block/.svn/text-base/blk-core.c.svn-base
@@ -0,0 +1,2173 @@
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright (C) 1994,      Karl Keyte: Added support for disk statistics
+ * Elevator latency, (C) 2000  Andrea Arcangeli <andrea@suse.de> SuSE
+ * Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de>
+ * kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au>
+ *	-  July2000
+ * bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001
+ */
+
+/*
+ * This handles all read/write requests to block devices
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/kernel_stat.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/blktrace_api.h>
+#include <linux/fault-inject.h>
+#include <trace/block.h>
+
+#include "blk.h"
+
+DEFINE_TRACE(block_plug);
+DEFINE_TRACE(block_unplug_io);
+DEFINE_TRACE(block_unplug_timer);
+DEFINE_TRACE(block_getrq);
+DEFINE_TRACE(block_sleeprq);
+DEFINE_TRACE(block_rq_requeue);
+DEFINE_TRACE(block_bio_backmerge);
+DEFINE_TRACE(block_bio_frontmerge);
+DEFINE_TRACE(block_bio_queue);
+DEFINE_TRACE(block_rq_complete);
+DEFINE_TRACE(block_remap);	/* Also used in drivers/md/dm.c */
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_remap);
+
+static int __make_request(struct request_queue *q, struct bio *bio);
+
+/*
+ * For the allocated request tables
+ */
+static struct kmem_cache *request_cachep;
+
+/*
+ * For queue allocation
+ */
+struct kmem_cache *blk_requestq_cachep;
+
+/*
+ * Controlling structure to kblockd
+ */
+static struct workqueue_struct *kblockd_workqueue;
+
+static void drive_stat_acct(struct request *rq, int new_io)
+{
+	struct gendisk *disk = rq->rq_disk;
+	struct hd_struct *part;
+	int rw = rq_data_dir(rq);
+	int cpu;
+
+	if (!blk_fs_request(rq) || !disk || !blk_do_io_stat(disk->queue))
+		return;
+
+	cpu = part_stat_lock();
+	part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
+
+	if (!new_io)
+		part_stat_inc(cpu, part, merges[rw]);
+	else {
+		part_round_stats(cpu, part);
+		part_inc_in_flight(part);
+	}
+
+	part_stat_unlock();
+}
+
+void blk_queue_congestion_threshold(struct request_queue *q)
+{
+	int nr;
+
+	nr = q->nr_requests - (q->nr_requests / 8) + 1;
+	if (nr > q->nr_requests)
+		nr = q->nr_requests;
+	q->nr_congestion_on = nr;
+
+	nr = q->nr_requests - (q->nr_requests / 8) - (q->nr_requests / 16) - 1;
+	if (nr < 1)
+		nr = 1;
+	q->nr_congestion_off = nr;
+}
+
+/**
+ * blk_get_backing_dev_info - get the address of a queue's backing_dev_info
+ * @bdev:	device
+ *
+ * Locates the passed device's request queue and returns the address of its
+ * backing_dev_info
+ *
+ * Will return NULL if the request queue cannot be located.
+ */
+struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
+{
+	struct backing_dev_info *ret = NULL;
+	struct request_queue *q = bdev_get_queue(bdev);
+
+	if (q)
+		ret = &q->backing_dev_info;
+	return ret;
+}
+EXPORT_SYMBOL(blk_get_backing_dev_info);
+
+void blk_rq_init(struct request_queue *q, struct request *rq)
+{
+	memset(rq, 0, sizeof(*rq));
+
+	INIT_LIST_HEAD(&rq->queuelist);
+	INIT_LIST_HEAD(&rq->timeout_list);
+	rq->cpu = -1;
+	rq->q = q;
+	rq->sector = rq->hard_sector = (sector_t) -1;
+	INIT_HLIST_NODE(&rq->hash);
+	RB_CLEAR_NODE(&rq->rb_node);
+	rq->cmd = rq->__cmd;
+	rq->tag = -1;
+	rq->ref_count = 1;
+}
+EXPORT_SYMBOL(blk_rq_init);
+
+static void req_bio_endio(struct request *rq, struct bio *bio,
+			  unsigned int nbytes, int error)
+{
+	struct request_queue *q = rq->q;
+
+	if (&q->bar_rq != rq) {
+		if (error)
+			clear_bit(BIO_UPTODATE, &bio->bi_flags);
+		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+			error = -EIO;
+
+		if (unlikely(nbytes > bio->bi_size)) {
+			printk(KERN_ERR "%s: want %u bytes done, %u left\n",
+			       __func__, nbytes, bio->bi_size);
+			nbytes = bio->bi_size;
+		}
+
+		if (unlikely(rq->cmd_flags & REQ_QUIET))
+			set_bit(BIO_QUIET, &bio->bi_flags);
+
+		bio->bi_size -= nbytes;
+		bio->bi_sector += (nbytes >> 9);
+
+		if (bio_integrity(bio))
+			bio_integrity_advance(bio, nbytes);
+
+		if (bio->bi_size == 0)
+			bio_endio(bio, error);
+	} else {
+
+		/*
+		 * Okay, this is the barrier request in progress, just
+		 * record the error;
+		 */
+		if (error && !q->orderr)
+			q->orderr = error;
+	}
+}
+
+void blk_dump_rq_flags(struct request *rq, char *msg)
+{
+	int bit;
+
+	printk(KERN_INFO "%s: dev %s: type=%x, flags=%x\n", msg,
+		rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type,
+		rq->cmd_flags);
+
+	printk(KERN_INFO "  sector %llu, nr/cnr %lu/%u\n",
+						(unsigned long long)rq->sector,
+						rq->nr_sectors,
+						rq->current_nr_sectors);
+	printk(KERN_INFO "  bio %p, biotail %p, buffer %p, data %p, len %u\n",
+						rq->bio, rq->biotail,
+						rq->buffer, rq->data,
+						rq->data_len);
+
+	if (blk_pc_request(rq)) {
+		printk(KERN_INFO "  cdb: ");
+		for (bit = 0; bit < BLK_MAX_CDB; bit++)
+			printk("%02x ", rq->cmd[bit]);
+		printk("\n");
+	}
+}
+EXPORT_SYMBOL(blk_dump_rq_flags);
+
+/*
+ * "plug" the device if there are no outstanding requests: this will
+ * force the transfer to start only after we have put all the requests
+ * on the list.
+ *
+ * This is called with interrupts off and no requests on the queue and
+ * with the queue lock held.
+ */
+void blk_plug_device(struct request_queue *q)
+{
+	WARN_ON(!irqs_disabled());
+
+	/*
+	 * don't plug a stopped queue, it must be paired with blk_start_queue()
+	 * which will restart the queueing
+	 */
+	if (blk_queue_stopped(q))
+		return;
+
+	if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) {
+		mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
+		trace_block_plug(q);
+	}
+}
+EXPORT_SYMBOL(blk_plug_device);
+
+/**
+ * blk_plug_device_unlocked - plug a device without queue lock held
+ * @q:    The &struct request_queue to plug
+ *
+ * Description:
+ *   Like @blk_plug_device(), but grabs the queue lock and disables
+ *   interrupts.
+ **/
+void blk_plug_device_unlocked(struct request_queue *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	blk_plug_device(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_plug_device_unlocked);
+
+/*
+ * remove the queue from the plugged list, if present. called with
+ * queue lock held and interrupts disabled.
+ */
+int blk_remove_plug(struct request_queue *q)
+{
+	WARN_ON(!irqs_disabled());
+
+	if (!queue_flag_test_and_clear(QUEUE_FLAG_PLUGGED, q))
+		return 0;
+
+	del_timer(&q->unplug_timer);
+	return 1;
+}
+EXPORT_SYMBOL(blk_remove_plug);
+
+/*
+ * remove the plug and let it rip..
+ */
+void __generic_unplug_device(struct request_queue *q)
+{
+	if (unlikely(blk_queue_stopped(q)))
+		return;
+	if (!blk_remove_plug(q) && !blk_queue_nonrot(q))
+		return;
+
+	q->request_fn(q);
+}
+
+/**
+ * generic_unplug_device - fire a request queue
+ * @q:    The &struct request_queue in question
+ *
+ * Description:
+ *   Linux uses plugging to build bigger requests queues before letting
+ *   the device have at them. If a queue is plugged, the I/O scheduler
+ *   is still adding and merging requests on the queue. Once the queue
+ *   gets unplugged, the request_fn defined for the queue is invoked and
+ *   transfers started.
+ **/
+void generic_unplug_device(struct request_queue *q)
+{
+	if (blk_queue_plugged(q)) {
+		spin_lock_irq(q->queue_lock);
+		__generic_unplug_device(q);
+		spin_unlock_irq(q->queue_lock);
+	}
+}
+EXPORT_SYMBOL(generic_unplug_device);
+
+static void blk_backing_dev_unplug(struct backing_dev_info *bdi,
+				   struct page *page)
+{
+	struct request_queue *q = bdi->unplug_io_data;
+
+	blk_unplug(q);
+}
+
+void blk_unplug_work(struct work_struct *work)
+{
+	struct request_queue *q =
+		container_of(work, struct request_queue, unplug_work);
+
+	trace_block_unplug_io(q);
+	q->unplug_fn(q);
+}
+
+void blk_unplug_timeout(unsigned long data)
+{
+	struct request_queue *q = (struct request_queue *)data;
+
+	trace_block_unplug_timer(q);
+	kblockd_schedule_work(q, &q->unplug_work);
+}
+
+void blk_unplug(struct request_queue *q)
+{
+	/*
+	 * devices don't necessarily have an ->unplug_fn defined
+	 */
+	if (q->unplug_fn) {
+		trace_block_unplug_io(q);
+		q->unplug_fn(q);
+	}
+}
+EXPORT_SYMBOL(blk_unplug);
+
+static void blk_invoke_request_fn(struct request_queue *q)
+{
+	if (unlikely(blk_queue_stopped(q)))
+		return;
+
+	/*
+	 * one level of recursion is ok and is much faster than kicking
+	 * the unplug handling
+	 */
+	if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
+		q->request_fn(q);
+		queue_flag_clear(QUEUE_FLAG_REENTER, q);
+	} else {
+		queue_flag_set(QUEUE_FLAG_PLUGGED, q);
+		kblockd_schedule_work(q, &q->unplug_work);
+	}
+}
+
+/**
+ * blk_start_queue - restart a previously stopped queue
+ * @q:    The &struct request_queue in question
+ *
+ * Description:
+ *   blk_start_queue() will clear the stop flag on the queue, and call
+ *   the request_fn for the queue if it was in a stopped state when
+ *   entered. Also see blk_stop_queue(). Queue lock must be held.
+ **/
+void blk_start_queue(struct request_queue *q)
+{
+	WARN_ON(!irqs_disabled());
+
+	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+	blk_invoke_request_fn(q);
+}
+EXPORT_SYMBOL(blk_start_queue);
+
+/**
+ * blk_stop_queue - stop a queue
+ * @q:    The &struct request_queue in question
+ *
+ * Description:
+ *   The Linux block layer assumes that a block driver will consume all
+ *   entries on the request queue when the request_fn strategy is called.
+ *   Often this will not happen, because of hardware limitations (queue
+ *   depth settings). If a device driver gets a 'queue full' response,
+ *   or if it simply chooses not to queue more I/O at one point, it can
+ *   call this function to prevent the request_fn from being called until
+ *   the driver has signalled it's ready to go again. This happens by calling
+ *   blk_start_queue() to restart queue operations. Queue lock must be held.
+ **/
+void blk_stop_queue(struct request_queue *q)
+{
+	blk_remove_plug(q);
+	queue_flag_set(QUEUE_FLAG_STOPPED, q);
+}
+EXPORT_SYMBOL(blk_stop_queue);
+
+/**
+ * blk_sync_queue - cancel any pending callbacks on a queue
+ * @q: the queue
+ *
+ * Description:
+ *     The block layer may perform asynchronous callback activity
+ *     on a queue, such as calling the unplug function after a timeout.
+ *     A block device may call blk_sync_queue to ensure that any
+ *     such activity is cancelled, thus allowing it to release resources
+ *     that the callbacks might use. The caller must already have made sure
+ *     that its ->make_request_fn will not re-add plugging prior to calling
+ *     this function.
+ *
+ */
+void blk_sync_queue(struct request_queue *q)
+{
+	del_timer_sync(&q->unplug_timer);
+	del_timer_sync(&q->timeout);
+	cancel_work_sync(&q->unplug_work);
+}
+EXPORT_SYMBOL(blk_sync_queue);
+
+/**
+ * __blk_run_queue - run a single device queue
+ * @q:	The queue to run
+ *
+ * Description:
+ *    See @blk_run_queue. This variant must be called with the queue lock
+ *    held and interrupts disabled.
+ *
+ */
+void __blk_run_queue(struct request_queue *q)
+{
+	blk_remove_plug(q);
+
+	/*
+	 * Only recurse once to avoid overrunning the stack, let the unplug
+	 * handling reinvoke the handler shortly if we already got there.
+	 */
+	if (!elv_queue_empty(q))
+		blk_invoke_request_fn(q);
+}
+EXPORT_SYMBOL(__blk_run_queue);
+
+/**
+ * blk_run_queue - run a single device queue
+ * @q: The queue to run
+ *
+ * Description:
+ *    Invoke request handling on this queue, if it has pending work to do.
+ *    May be used to restart queueing when a request has completed. Also
+ *    See @blk_start_queueing.
+ *
+ */
+void blk_run_queue(struct request_queue *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	__blk_run_queue(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_run_queue);
+
+void blk_put_queue(struct request_queue *q)
+{
+	kobject_put(&q->kobj);
+}
+
+void blk_cleanup_queue(struct request_queue *q)
+{
+	/*
+	 * We know we have process context here, so we can be a little
+	 * cautious and ensure that pending block actions on this device
+	 * are done before moving on. Going into this function, we should
+	 * not have processes doing IO to this device.
+	 */
+	blk_sync_queue(q);
+
+	mutex_lock(&q->sysfs_lock);
+	queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
+	mutex_unlock(&q->sysfs_lock);
+
+	if (q->elevator)
+		elevator_exit(q->elevator);
+
+	blk_put_queue(q);
+}
+EXPORT_SYMBOL(blk_cleanup_queue);
+
+static int blk_init_free_list(struct request_queue *q)
+{
+	struct request_list *rl = &q->rq;
+
+	rl->count[READ] = rl->count[WRITE] = 0;
+	rl->starved[READ] = rl->starved[WRITE] = 0;
+	rl->elvpriv = 0;
+	init_waitqueue_head(&rl->wait[READ]);
+	init_waitqueue_head(&rl->wait[WRITE]);
+
+	rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
+				mempool_free_slab, request_cachep, q->node);
+
+	if (!rl->rq_pool)
+		return -ENOMEM;
+
+	return 0;
+}
+
+struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
+{
+	return blk_alloc_queue_node(gfp_mask, -1);
+}
+EXPORT_SYMBOL(blk_alloc_queue);
+
+struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
+{
+	struct request_queue *q;
+	int err;
+
+	q = kmem_cache_alloc_node(blk_requestq_cachep,
+				gfp_mask | __GFP_ZERO, node_id);
+	if (!q)
+		return NULL;
+
+	q->backing_dev_info.unplug_io_fn = blk_backing_dev_unplug;
+	q->backing_dev_info.unplug_io_data = q;
+	err = bdi_init(&q->backing_dev_info);
+	if (err) {
+		kmem_cache_free(blk_requestq_cachep, q);
+		return NULL;
+	}
+
+	init_timer(&q->unplug_timer);
+	setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
+	INIT_LIST_HEAD(&q->timeout_list);
+	INIT_WORK(&q->unplug_work, blk_unplug_work);
+
+	kobject_init(&q->kobj, &blk_queue_ktype);
+
+	mutex_init(&q->sysfs_lock);
+	spin_lock_init(&q->__queue_lock);
+
+	return q;
+}
+EXPORT_SYMBOL(blk_alloc_queue_node);
+
+/**
+ * blk_init_queue  - prepare a request queue for use with a block device
+ * @rfn:  The function to be called to process requests that have been
+ *        placed on the queue.
+ * @lock: Request queue spin lock
+ *
+ * Description:
+ *    If a block device wishes to use the standard request handling procedures,
+ *    which sorts requests and coalesces adjacent requests, then it must
+ *    call blk_init_queue().  The function @rfn will be called when there
+ *    are requests on the queue that need to be processed.  If the device
+ *    supports plugging, then @rfn may not be called immediately when requests
+ *    are available on the queue, but may be called at some time later instead.
+ *    Plugged queues are generally unplugged when a buffer belonging to one
+ *    of the requests on the queue is needed, or due to memory pressure.
+ *
+ *    @rfn is not required, or even expected, to remove all requests off the
+ *    queue, but only as many as it can handle at a time.  If it does leave
+ *    requests on the queue, it is responsible for arranging that the requests
+ *    get dealt with eventually.
+ *
+ *    The queue spin lock must be held while manipulating the requests on the
+ *    request queue; this lock will be taken also from interrupt context, so irq
+ *    disabling is needed for it.
+ *
+ *    Function returns a pointer to the initialized request queue, or %NULL if
+ *    it didn't succeed.
+ *
+ * Note:
+ *    blk_init_queue() must be paired with a blk_cleanup_queue() call
+ *    when the block device is deactivated (such as at module unload).
+ **/
+
+struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock)
+{
+	return blk_init_queue_node(rfn, lock, -1);
+}
+EXPORT_SYMBOL(blk_init_queue);
+
+struct request_queue *
+blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
+{
+	struct request_queue *q = blk_alloc_queue_node(GFP_KERNEL, node_id);
+
+	if (!q)
+		return NULL;
+
+	q->node = node_id;
+	if (blk_init_free_list(q)) {
+		kmem_cache_free(blk_requestq_cachep, q);
+		return NULL;
+	}
+
+	/*
+	 * if caller didn't supply a lock, they get per-queue locking with
+	 * our embedded lock
+	 */
+	if (!lock)
+		lock = &q->__queue_lock;
+
+	q->request_fn		= rfn;
+	q->prep_rq_fn		= NULL;
+	q->unplug_fn		= generic_unplug_device;
+	q->queue_flags		= QUEUE_FLAG_DEFAULT;
+	q->queue_lock		= lock;
+
+	blk_queue_segment_boundary(q, BLK_SEG_BOUNDARY_MASK);
+
+	blk_queue_make_request(q, __make_request);
+	blk_queue_max_segment_size(q, MAX_SEGMENT_SIZE);
+
+	blk_queue_max_hw_segments(q, MAX_HW_SEGMENTS);
+	blk_queue_max_phys_segments(q, MAX_PHYS_SEGMENTS);
+
+	q->sg_reserved_size = INT_MAX;
+
+	blk_set_cmd_filter_defaults(&q->cmd_filter);
+
+	/*
+	 * all done
+	 */
+	if (!elevator_init(q, NULL)) {
+		blk_queue_congestion_threshold(q);
+		return q;
+	}
+
+	blk_put_queue(q);
+	return NULL;
+}
+EXPORT_SYMBOL(blk_init_queue_node);
+
+int blk_get_queue(struct request_queue *q)
+{
+	if (likely(!test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
+		kobject_get(&q->kobj);
+		return 0;
+	}
+
+	return 1;
+}
+
+static inline void blk_free_request(struct request_queue *q, struct request *rq)
+{
+	if (rq->cmd_flags & REQ_ELVPRIV)
+		elv_put_request(q, rq);
+	mempool_free(rq, q->rq.rq_pool);
+}
+
+static struct request *
+blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
+{
+	struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
+
+	if (!rq)
+		return NULL;
+
+	blk_rq_init(q, rq);
+
+	rq->cmd_flags = rw | REQ_ALLOCED;
+
+	if (priv) {
+		if (unlikely(elv_set_request(q, rq, gfp_mask))) {
+			mempool_free(rq, q->rq.rq_pool);
+			return NULL;
+		}
+		rq->cmd_flags |= REQ_ELVPRIV;
+	}
+
+	return rq;
+}
+
+/*
+ * ioc_batching returns true if the ioc is a valid batching request and
+ * should be given priority access to a request.
+ */
+static inline int ioc_batching(struct request_queue *q, struct io_context *ioc)
+{
+	if (!ioc)
+		return 0;
+
+	/*
+	 * Make sure the process is able to allocate at least 1 request
+	 * even if the batch times out, otherwise we could theoretically
+	 * lose wakeups.
+	 */
+	return ioc->nr_batch_requests == q->nr_batching ||
+		(ioc->nr_batch_requests > 0
+		&& time_before(jiffies, ioc->last_waited + BLK_BATCH_TIME));
+}
+
+/*
+ * ioc_set_batching sets ioc to be a new "batcher" if it is not one. This
+ * will cause the process to be a "batcher" on all queues in the system. This
+ * is the behaviour we want though - once it gets a wakeup it should be given
+ * a nice run.
+ */
+static void ioc_set_batching(struct request_queue *q, struct io_context *ioc)
+{
+	if (!ioc || ioc_batching(q, ioc))
+		return;
+
+	ioc->nr_batch_requests = q->nr_batching;
+	ioc->last_waited = jiffies;
+}
+
+static void __freed_request(struct request_queue *q, int rw)
+{
+	struct request_list *rl = &q->rq;
+
+	if (rl->count[rw] < queue_congestion_off_threshold(q))
+		blk_clear_queue_congested(q, rw);
+
+	if (rl->count[rw] + 1 <= q->nr_requests) {
+		if (waitqueue_active(&rl->wait[rw]))
+			wake_up(&rl->wait[rw]);
+
+		blk_clear_queue_full(q, rw);
+	}
+}
+
+/*
+ * A request has just been released.  Account for it, update the full and
+ * congestion status, wake up any waiters.   Called under q->queue_lock.
+ */
+static void freed_request(struct request_queue *q, int rw, int priv)
+{
+	struct request_list *rl = &q->rq;
+
+	rl->count[rw]--;
+	if (priv)
+		rl->elvpriv--;
+
+	__freed_request(q, rw);
+
+	if (unlikely(rl->starved[rw ^ 1]))
+		__freed_request(q, rw ^ 1);
+}
+
+#define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist)
+/*
+ * Get a free request, queue_lock must be held.
+ * Returns NULL on failure, with queue_lock held.
+ * Returns !NULL on success, with queue_lock *not held*.
+ */
+static struct request *get_request(struct request_queue *q, int rw_flags,
+				   struct bio *bio, gfp_t gfp_mask)
+{
+	struct request *rq = NULL;
+	struct request_list *rl = &q->rq;
+	struct io_context *ioc = NULL;
+	const int rw = rw_flags & 0x01;
+	int may_queue, priv;
+
+	may_queue = elv_may_queue(q, rw_flags);
+	if (may_queue == ELV_MQUEUE_NO)
+		goto rq_starved;
+
+	if (rl->count[rw]+1 >= queue_congestion_on_threshold(q)) {
+		if (rl->count[rw]+1 >= q->nr_requests) {
+			ioc = current_io_context(GFP_ATOMIC, q->node);
+			/*
+			 * The queue will fill after this allocation, so set
+			 * it as full, and mark this process as "batching".
+			 * This process will be allowed to complete a batch of
+			 * requests, others will be blocked.
+			 */
+			if (!blk_queue_full(q, rw)) {
+				ioc_set_batching(q, ioc);
+				blk_set_queue_full(q, rw);
+			} else {
+				if (may_queue != ELV_MQUEUE_MUST
+						&& !ioc_batching(q, ioc)) {
+					/*
+					 * The queue is full and the allocating
+					 * process is not a "batcher", and not
+					 * exempted by the IO scheduler
+					 */
+					goto out;
+				}
+			}
+		}
+		blk_set_queue_congested(q, rw);
+	}
+
+	/*
+	 * Only allow batching queuers to allocate up to 50% over the defined
+	 * limit of requests, otherwise we could have thousands of requests
+	 * allocated with any setting of ->nr_requests
+	 */
+	if (rl->count[rw] >= (3 * q->nr_requests / 2))
+		goto out;
+
+	rl->count[rw]++;
+	rl->starved[rw] = 0;
+
+	priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+	if (priv)
+		rl->elvpriv++;
+
+	spin_unlock_irq(q->queue_lock);
+
+	rq = blk_alloc_request(q, rw_flags, priv, gfp_mask);
+	if (unlikely(!rq)) {
+		/*
+		 * Allocation failed presumably due to memory. Undo anything
+		 * we might have messed up.
+		 *
+		 * Allocating task should really be put onto the front of the
+		 * wait queue, but this is pretty rare.
+		 */
+		spin_lock_irq(q->queue_lock);
+		freed_request(q, rw, priv);
+
+		/*
+		 * in the very unlikely event that allocation failed and no
+		 * requests for this direction was pending, mark us starved
+		 * so that freeing of a request in the other direction will
+		 * notice us. another possible fix would be to split the
+		 * rq mempool into READ and WRITE
+		 */
+rq_starved:
+		if (unlikely(rl->count[rw] == 0))
+			rl->starved[rw] = 1;
+
+		goto out;
+	}
+
+	/*
+	 * ioc may be NULL here, and ioc_batching will be false. That's
+	 * OK, if the queue is under the request limit then requests need
+	 * not count toward the nr_batch_requests limit. There will always
+	 * be some limit enforced by BLK_BATCH_TIME.
+	 */
+	if (ioc_batching(q, ioc))
+		ioc->nr_batch_requests--;
+
+	trace_block_getrq(q, bio, rw);
+out:
+	return rq;
+}
+
+/*
+ * No available requests for this queue, unplug the device and wait for some
+ * requests to become available.
+ *
+ * Called with q->queue_lock held, and returns with it unlocked.
+ */
+static struct request *get_request_wait(struct request_queue *q, int rw_flags,
+					struct bio *bio)
+{
+	const int rw = rw_flags & 0x01;
+	struct request *rq;
+
+	rq = get_request(q, rw_flags, bio, GFP_NOIO);
+	while (!rq) {
+		DEFINE_WAIT(wait);
+		struct io_context *ioc;
+		struct request_list *rl = &q->rq;
+
+		prepare_to_wait_exclusive(&rl->wait[rw], &wait,
+				TASK_UNINTERRUPTIBLE);
+
+		trace_block_sleeprq(q, bio, rw);
+
+		__generic_unplug_device(q);
+		spin_unlock_irq(q->queue_lock);
+		io_schedule();
+
+		/*
+		 * After sleeping, we become a "batching" process and
+		 * will be able to allocate at least one request, and
+		 * up to a big batch of them for a small period time.
+		 * See ioc_batching, ioc_set_batching
+		 */
+		ioc = current_io_context(GFP_NOIO, q->node);
+		ioc_set_batching(q, ioc);
+
+		spin_lock_irq(q->queue_lock);
+		finish_wait(&rl->wait[rw], &wait);
+
+		rq = get_request(q, rw_flags, bio, GFP_NOIO);
+	};
+
+	return rq;
+}
+
+struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
+{
+	struct request *rq;
+
+	BUG_ON(rw != READ && rw != WRITE);
+
+	spin_lock_irq(q->queue_lock);
+	if (gfp_mask & __GFP_WAIT) {
+		rq = get_request_wait(q, rw, NULL);
+	} else {
+		rq = get_request(q, rw, NULL, gfp_mask);
+		if (!rq)
+			spin_unlock_irq(q->queue_lock);
+	}
+	/* q->queue_lock is unlocked at this point */
+
+	return rq;
+}
+EXPORT_SYMBOL(blk_get_request);
+
+/**
+ * blk_start_queueing - initiate dispatch of requests to device
+ * @q:		request queue to kick into gear
+ *
+ * This is basically a helper to remove the need to know whether a queue
+ * is plugged or not if someone just wants to initiate dispatch of requests
+ * for this queue. Should be used to start queueing on a device outside
+ * of ->request_fn() context. Also see @blk_run_queue.
+ *
+ * The queue lock must be held with interrupts disabled.
+ */
+void blk_start_queueing(struct request_queue *q)
+{
+	if (!blk_queue_plugged(q)) {
+		if (unlikely(blk_queue_stopped(q)))
+			return;
+		q->request_fn(q);
+	} else
+		__generic_unplug_device(q);
+}
+EXPORT_SYMBOL(blk_start_queueing);
+
+/**
+ * blk_requeue_request - put a request back on queue
+ * @q:		request queue where request should be inserted
+ * @rq:		request to be inserted
+ *
+ * Description:
+ *    Drivers often keep queueing requests until the hardware cannot accept
+ *    more, when that condition happens we need to put the request back
+ *    on the queue. Must be called with queue lock held.
+ */
+void blk_requeue_request(struct request_queue *q, struct request *rq)
+{
+	blk_delete_timer(rq);
+	blk_clear_rq_complete(rq);
+	trace_block_rq_requeue(q, rq);
+
+	if (blk_rq_tagged(rq))
+		blk_queue_end_tag(q, rq);
+
+	elv_requeue_request(q, rq);
+}
+EXPORT_SYMBOL(blk_requeue_request);
+
+/**
+ * blk_insert_request - insert a special request into a request queue
+ * @q:		request queue where request should be inserted
+ * @rq:		request to be inserted
+ * @at_head:	insert request at head or tail of queue
+ * @data:	private data
+ *
+ * Description:
+ *    Many block devices need to execute commands asynchronously, so they don't
+ *    block the whole kernel from preemption during request execution.  This is
+ *    accomplished normally by inserting aritficial requests tagged as
+ *    REQ_TYPE_SPECIAL in to the corresponding request queue, and letting them
+ *    be scheduled for actual execution by the request queue.
+ *
+ *    We have the option of inserting the head or the tail of the queue.
+ *    Typically we use the tail for new ioctls and so forth.  We use the head
+ *    of the queue for things like a QUEUE_FULL message from a device, or a
+ *    host that is unable to accept a particular command.
+ */
+void blk_insert_request(struct request_queue *q, struct request *rq,
+			int at_head, void *data)
+{
+	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+	unsigned long flags;
+
+	/*
+	 * tell I/O scheduler that this isn't a regular read/write (ie it
+	 * must not attempt merges on this) and that it acts as a soft
+	 * barrier
+	 */
+	rq->cmd_type = REQ_TYPE_SPECIAL;
+	rq->cmd_flags |= REQ_SOFTBARRIER;
+
+	rq->special = data;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+
+	/*
+	 * If command is tagged, release the tag
+	 */
+	if (blk_rq_tagged(rq))
+		blk_queue_end_tag(q, rq);
+
+	drive_stat_acct(rq, 1);
+	__elv_add_request(q, rq, where, 0);
+	blk_start_queueing(q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_insert_request);
+
+/*
+ * add-request adds a request to the linked list.
+ * queue lock is held and interrupts disabled, as we muck with the
+ * request queue list.
+ */
+static inline void add_request(struct request_queue *q, struct request *req)
+{
+	drive_stat_acct(req, 1);
+
+	/*
+	 * elevator indicated where it wants this request to be
+	 * inserted at elevator_merge time
+	 */
+	__elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
+}
+
+static void part_round_stats_single(int cpu, struct hd_struct *part,
+				    unsigned long now)
+{
+	if (now == part->stamp)
+		return;
+
+	if (part->in_flight) {
+		__part_stat_add(cpu, part, time_in_queue,
+				part->in_flight * (now - part->stamp));
+		__part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+	}
+	part->stamp = now;
+}
+
+/**
+ * part_round_stats() - Round off the performance stats on a struct disk_stats.
+ * @cpu: cpu number for stats access
+ * @part: target partition
+ *
+ * The average IO queue length and utilisation statistics are maintained
+ * by observing the current state of the queue length and the amount of
+ * time it has been in this state for.
+ *
+ * Normally, that accounting is done on IO completion, but that can result
+ * in more than a second's worth of IO being accounted for within any one
+ * second, leading to >100% utilisation.  To deal with that, we call this
+ * function to do a round-off before returning the results when reading
+ * /proc/diskstats.  This accounts immediately for all queue usage up to
+ * the current jiffies and restarts the counters again.
+ */
+void part_round_stats(int cpu, struct hd_struct *part)
+{
+	unsigned long now = jiffies;
+
+	if (part->partno)
+		part_round_stats_single(cpu, &part_to_disk(part)->part0, now);
+	part_round_stats_single(cpu, part, now);
+}
+EXPORT_SYMBOL_GPL(part_round_stats);
+
+/*
+ * queue lock must be held
+ */
+void __blk_put_request(struct request_queue *q, struct request *req)
+{
+	if (unlikely(!q))
+		return;
+	if (unlikely(--req->ref_count))
+		return;
+
+	elv_completed_request(q, req);
+
+	/*
+	 * Request may not have originated from ll_rw_blk. if not,
+	 * it didn't come out of our reserved rq pools
+	 */
+	if (req->cmd_flags & REQ_ALLOCED) {
+		int rw = rq_data_dir(req);
+		int priv = req->cmd_flags & REQ_ELVPRIV;
+
+		BUG_ON(!list_empty(&req->queuelist));
+		BUG_ON(!hlist_unhashed(&req->hash));
+
+		blk_free_request(q, req);
+		freed_request(q, rw, priv);
+	}
+}
+EXPORT_SYMBOL_GPL(__blk_put_request);
+
+void blk_put_request(struct request *req)
+{
+	unsigned long flags;
+	struct request_queue *q = req->q;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	__blk_put_request(q, req);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_put_request);
+
+void init_request_from_bio(struct request *req, struct bio *bio)
+{
+	req->cpu = bio->bi_comp_cpu;
+	req->cmd_type = REQ_TYPE_FS;
+
+	/*
+	 * inherit FAILFAST from bio (for read-ahead, and explicit FAILFAST)
+	 */
+	if (bio_rw_ahead(bio))
+		req->cmd_flags |= (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
+				   REQ_FAILFAST_DRIVER);
+	if (bio_failfast_dev(bio))
+		req->cmd_flags |= REQ_FAILFAST_DEV;
+	if (bio_failfast_transport(bio))
+		req->cmd_flags |= REQ_FAILFAST_TRANSPORT;
+	if (bio_failfast_driver(bio))
+		req->cmd_flags |= REQ_FAILFAST_DRIVER;
+
+	/*
+	 * REQ_BARRIER implies no merging, but lets make it explicit
+	 */
+	if (unlikely(bio_discard(bio))) {
+		req->cmd_flags |= REQ_DISCARD;
+		if (bio_barrier(bio))
+			req->cmd_flags |= REQ_SOFTBARRIER;
+		req->q->prepare_discard_fn(req->q, req);
+	} else if (unlikely(bio_barrier(bio)))
+		req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+
+	if (bio_sync(bio))
+		req->cmd_flags |= REQ_RW_SYNC;
+	if (bio_unplug(bio))
+		req->cmd_flags |= REQ_UNPLUG;
+	if (bio_rw_meta(bio))
+		req->cmd_flags |= REQ_RW_META;
+
+	req->errors = 0;
+	req->hard_sector = req->sector = bio->bi_sector;
+	req->ioprio = bio_prio(bio);
+	req->start_time = jiffies;
+	blk_rq_bio_prep(req->q, req, bio);
+}
+
+static int __make_request(struct request_queue *q, struct bio *bio)
+{
+	struct request *req;
+	int el_ret, nr_sectors;
+	const unsigned short prio = bio_prio(bio);
+	const int sync = bio_sync(bio);
+	const int unplug = bio_unplug(bio);
+	int rw_flags;
+
+	nr_sectors = bio_sectors(bio);
+
+	/*
+	 * low level driver can indicate that it wants pages above a
+	 * certain limit bounced to low memory (ie for highmem, or even
+	 * ISA dma in theory)
+	 */
+	blk_queue_bounce(q, &bio);
+
+	spin_lock_irq(q->queue_lock);
+
+	if (unlikely(bio_barrier(bio)) || elv_queue_empty(q))
+		goto get_rq;
+
+	el_ret = elv_merge(q, &req, bio);
+	switch (el_ret) {
+	case ELEVATOR_BACK_MERGE:
+		BUG_ON(!rq_mergeable(req));
+
+		if (!ll_back_merge_fn(q, req, bio))
+			break;
+
+		trace_block_bio_backmerge(q, bio);
+
+		req->biotail->bi_next = bio;
+		req->biotail = bio;
+		req->nr_sectors = req->hard_nr_sectors += nr_sectors;
+		req->ioprio = ioprio_best(req->ioprio, prio);
+		if (!blk_rq_cpu_valid(req))
+			req->cpu = bio->bi_comp_cpu;
+		drive_stat_acct(req, 0);
+		if (!attempt_back_merge(q, req))
+			elv_merged_request(q, req, el_ret);
+		goto out;
+
+	case ELEVATOR_FRONT_MERGE:
+		BUG_ON(!rq_mergeable(req));
+
+		if (!ll_front_merge_fn(q, req, bio))
+			break;
+
+		trace_block_bio_frontmerge(q, bio);
+
+		bio->bi_next = req->bio;
+		req->bio = bio;
+
+		/*
+		 * may not be valid. if the low level driver said
+		 * it didn't need a bounce buffer then it better
+		 * not touch req->buffer either...
+		 */
+		req->buffer = bio_data(bio);
+		req->current_nr_sectors = bio_cur_sectors(bio);
+		req->hard_cur_sectors = req->current_nr_sectors;
+		req->sector = req->hard_sector = bio->bi_sector;
+		req->nr_sectors = req->hard_nr_sectors += nr_sectors;
+		req->ioprio = ioprio_best(req->ioprio, prio);
+		if (!blk_rq_cpu_valid(req))
+			req->cpu = bio->bi_comp_cpu;
+		drive_stat_acct(req, 0);
+		if (!attempt_front_merge(q, req))
+			elv_merged_request(q, req, el_ret);
+		goto out;
+
+	/* ELV_NO_MERGE: elevator says don't/can't merge. */
+	default:
+		;
+	}
+
+get_rq:
+	/*
+	 * This sync check and mask will be re-done in init_request_from_bio(),
+	 * but we need to set it earlier to expose the sync flag to the
+	 * rq allocator and io schedulers.
+	 */
+	rw_flags = bio_data_dir(bio);
+	if (sync)
+		rw_flags |= REQ_RW_SYNC;
+
+	/*
+	 * Grab a free request. This is might sleep but can not fail.
+	 * Returns with the queue unlocked.
+	 */
+	req = get_request_wait(q, rw_flags, bio);
+
+	/*
+	 * After dropping the lock and possibly sleeping here, our request
+	 * may now be mergeable after it had proven unmergeable (above).
+	 * We don't worry about that case for efficiency. It won't happen
+	 * often, and the elevators are able to handle it.
+	 */
+	init_request_from_bio(req, bio);
+
+	spin_lock_irq(q->queue_lock);
+	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
+	    bio_flagged(bio, BIO_CPU_AFFINE))
+		req->cpu = blk_cpu_to_group(smp_processor_id());
+	if (!blk_queue_nonrot(q) && elv_queue_empty(q))
+		blk_plug_device(q);
+	add_request(q, req);
+out:
+	if (unplug || blk_queue_nonrot(q))
+		__generic_unplug_device(q);
+	spin_unlock_irq(q->queue_lock);
+	return 0;
+}
+
+/*
+ * If bio->bi_dev is a partition, remap the location
+ */
+static inline void blk_partition_remap(struct bio *bio)
+{
+	struct block_device *bdev = bio->bi_bdev;
+
+	if (bio_sectors(bio) && bdev != bdev->bd_contains) {
+		struct hd_struct *p = bdev->bd_part;
+
+		bio->bi_sector += p->start_sect;
+		bio->bi_bdev = bdev->bd_contains;
+
+		trace_block_remap(bdev_get_queue(bio->bi_bdev), bio,
+				    bdev->bd_dev, bio->bi_sector,
+				    bio->bi_sector - p->start_sect);
+	}
+}
+
+static void handle_bad_sector(struct bio *bio)
+{
+	char b[BDEVNAME_SIZE];
+
+	printk(KERN_INFO "attempt to access beyond end of device\n");
+	printk(KERN_INFO "%s: rw=%ld, want=%Lu, limit=%Lu\n",
+			bdevname(bio->bi_bdev, b),
+			bio->bi_rw,
+			(unsigned long long)bio->bi_sector + bio_sectors(bio),
+			(long long)(bio->bi_bdev->bd_inode->i_size >> 9));
+
+	set_bit(BIO_EOF, &bio->bi_flags);
+}
+
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+
+static DECLARE_FAULT_ATTR(fail_make_request);
+
+static int __init setup_fail_make_request(char *str)
+{
+	return setup_fault_attr(&fail_make_request, str);
+}
+__setup("fail_make_request=", setup_fail_make_request);
+
+static int should_fail_request(struct bio *bio)
+{
+	struct hd_struct *part = bio->bi_bdev->bd_part;
+
+	if (part_to_disk(part)->part0.make_it_fail || part->make_it_fail)
+		return should_fail(&fail_make_request, bio->bi_size);
+
+	return 0;
+}
+
+static int __init fail_make_request_debugfs(void)
+{
+	return init_fault_attr_dentries(&fail_make_request,
+					"fail_make_request");
+}
+
+late_initcall(fail_make_request_debugfs);
+
+#else /* CONFIG_FAIL_MAKE_REQUEST */
+
+static inline int should_fail_request(struct bio *bio)
+{
+	return 0;
+}
+
+#endif /* CONFIG_FAIL_MAKE_REQUEST */
+
+/*
+ * Check whether this bio extends beyond the end of the device.
+ */
+static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
+{
+	sector_t maxsector;
+
+	if (!nr_sectors)
+		return 0;
+
+	/* Test device or partition size, when known. */
+	maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
+	if (maxsector) {
+		sector_t sector = bio->bi_sector;
+
+		if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
+			/*
+			 * This may well happen - the kernel calls bread()
+			 * without checking the size of the device, e.g., when
+			 * mounting a device.
+			 */
+			handle_bad_sector(bio);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * generic_make_request - hand a buffer to its device driver for I/O
+ * @bio:  The bio describing the location in memory and on the device.
+ *
+ * generic_make_request() is used to make I/O requests of block
+ * devices. It is passed a &struct bio, which describes the I/O that needs
+ * to be done.
+ *
+ * generic_make_request() does not return any status.  The
+ * success/failure status of the request, along with notification of
+ * completion, is delivered asynchronously through the bio->bi_end_io
+ * function described (one day) else where.
+ *
+ * The caller of generic_make_request must make sure that bi_io_vec
+ * are set to describe the memory buffer, and that bi_dev and bi_sector are
+ * set to describe the device address, and the
+ * bi_end_io and optionally bi_private are set to describe how
+ * completion notification should be signaled.
+ *
+ * generic_make_request and the drivers it calls may use bi_next if this
+ * bio happens to be merged with someone else, and may change bi_dev and
+ * bi_sector for remaps as it sees fit.  So the values of these fields
+ * should NOT be depended on after the call to generic_make_request.
+ */
+static inline void __generic_make_request(struct bio *bio)
+{
+	struct request_queue *q;
+	sector_t old_sector;
+	int ret, nr_sectors = bio_sectors(bio);
+	dev_t old_dev;
+	int err = -EIO;
+
+	might_sleep();
+
+	if (bio_check_eod(bio, nr_sectors))
+		goto end_io;
+
+	/*
+	 * Resolve the mapping until finished. (drivers are
+	 * still free to implement/resolve their own stacking
+	 * by explicitly returning 0)
+	 *
+	 * NOTE: we don't repeat the blk_size check for each new device.
+	 * Stacking drivers are expected to know what they are doing.
+	 */
+	old_sector = -1;
+	old_dev = 0;
+	do {
+		char b[BDEVNAME_SIZE];
+
+		q = bdev_get_queue(bio->bi_bdev);
+		if (unlikely(!q)) {
+			printk(KERN_ERR
+			       "generic_make_request: Trying to access "
+				"nonexistent block-device %s (%Lu)\n",
+				bdevname(bio->bi_bdev, b),
+				(long long) bio->bi_sector);
+			goto end_io;
+		}
+
+		if (unlikely(nr_sectors > q->max_hw_sectors)) {
+			printk(KERN_ERR "bio too big device %s (%u > %u)\n",
+				bdevname(bio->bi_bdev, b),
+				bio_sectors(bio),
+				q->max_hw_sectors);
+			goto end_io;
+		}
+
+		if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
+			goto end_io;
+
+		if (should_fail_request(bio))
+			goto end_io;
+
+		/*
+		 * If this device has partitions, remap block n
+		 * of partition p to block n+start(p) of the disk.
+		 */
+		blk_partition_remap(bio);
+
+		if (bio_integrity_enabled(bio) && bio_integrity_prep(bio))
+			goto end_io;
+
+		if (old_sector != -1)
+			trace_block_remap(q, bio, old_dev, bio->bi_sector,
+					    old_sector);
+
+		trace_block_bio_queue(q, bio);
+
+		old_sector = bio->bi_sector;
+		old_dev = bio->bi_bdev->bd_dev;
+
+		if (bio_check_eod(bio, nr_sectors))
+			goto end_io;
+
+		if (bio_discard(bio) && !q->prepare_discard_fn) {
+			err = -EOPNOTSUPP;
+			goto end_io;
+		}
+		if (bio_barrier(bio) && bio_has_data(bio) &&
+		    (q->next_ordered == QUEUE_ORDERED_NONE)) {
+			err = -EOPNOTSUPP;
+			goto end_io;
+		}
+
+		ret = q->make_request_fn(q, bio);
+	} while (ret);
+
+	return;
+
+end_io:
+	bio_endio(bio, err);
+}
+
+/*
+ * We only want one ->make_request_fn to be active at a time,
+ * else stack usage with stacked devices could be a problem.
+ * So use current->bio_{list,tail} to keep a list of requests
+ * submited by a make_request_fn function.
+ * current->bio_tail is also used as a flag to say if
+ * generic_make_request is currently active in this task or not.
+ * If it is NULL, then no make_request is active.  If it is non-NULL,
+ * then a make_request is active, and new requests should be added
+ * at the tail
+ */
+void generic_make_request(struct bio *bio)
+{
+	if (current->bio_tail) {
+		/* make_request is active */
+		*(current->bio_tail) = bio;
+		bio->bi_next = NULL;
+		current->bio_tail = &bio->bi_next;
+		return;
+	}
+	/* following loop may be a bit non-obvious, and so deserves some
+	 * explanation.
+	 * Before entering the loop, bio->bi_next is NULL (as all callers
+	 * ensure that) so we have a list with a single bio.
+	 * We pretend that we have just taken it off a longer list, so
+	 * we assign bio_list to the next (which is NULL) and bio_tail
+	 * to &bio_list, thus initialising the bio_list of new bios to be
+	 * added.  __generic_make_request may indeed add some more bios
+	 * through a recursive call to generic_make_request.  If it
+	 * did, we find a non-NULL value in bio_list and re-enter the loop
+	 * from the top.  In this case we really did just take the bio
+	 * of the top of the list (no pretending) and so fixup bio_list and
+	 * bio_tail or bi_next, and call into __generic_make_request again.
+	 *
+	 * The loop was structured like this to make only one call to
+	 * __generic_make_request (which is important as it is large and
+	 * inlined) and to keep the structure simple.
+	 */
+	BUG_ON(bio->bi_next);
+	do {
+		current->bio_list = bio->bi_next;
+		if (bio->bi_next == NULL)
+			current->bio_tail = &current->bio_list;
+		else
+			bio->bi_next = NULL;
+		__generic_make_request(bio);
+		bio = current->bio_list;
+	} while (bio);
+	current->bio_tail = NULL; /* deactivate */
+}
+EXPORT_SYMBOL(generic_make_request);
+
+/**
+ * submit_bio - submit a bio to the block device layer for I/O
+ * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead)
+ * @bio: The &struct bio which describes the I/O
+ *
+ * submit_bio() is very similar in purpose to generic_make_request(), and
+ * uses that function to do most of the work. Both are fairly rough
+ * interfaces; @bio must be presetup and ready for I/O.
+ *
+ */
+void submit_bio(int rw, struct bio *bio)
+{
+	int count = bio_sectors(bio);
+
+	bio->bi_rw |= rw;
+
+	/*
+	 * If it's a regular read/write or a barrier with data attached,
+	 * go through the normal accounting stuff before submission.
+	 */
+	if (bio_has_data(bio)) {
+		if (rw & WRITE) {
+			count_vm_events(PGPGOUT, count);
+		} else {
+			task_io_account_read(bio->bi_size);
+			count_vm_events(PGPGIN, count);
+		}
+
+		if (unlikely(block_dump)) {
+			char b[BDEVNAME_SIZE];
+			printk(KERN_DEBUG "%s(%d): %s block %Lu on %s\n",
+			current->comm, task_pid_nr(current),
+				(rw & WRITE) ? "WRITE" : "READ",
+				(unsigned long long)bio->bi_sector,
+				bdevname(bio->bi_bdev, b));
+		}
+	}
+
+	generic_make_request(bio);
+}
+EXPORT_SYMBOL(submit_bio);
+
+/**
+ * blk_rq_check_limits - Helper function to check a request for the queue limit
+ * @q:  the queue
+ * @rq: the request being checked
+ *
+ * Description:
+ *    @rq may have been made based on weaker limitations of upper-level queues
+ *    in request stacking drivers, and it may violate the limitation of @q.
+ *    Since the block layer and the underlying device driver trust @rq
+ *    after it is inserted to @q, it should be checked against @q before
+ *    the insertion using this generic function.
+ *
+ *    This function should also be useful for request stacking drivers
+ *    in some cases below, so export this fuction.
+ *    Request stacking drivers like request-based dm may change the queue
+ *    limits while requests are in the queue (e.g. dm's table swapping).
+ *    Such request stacking drivers should check those requests agaist
+ *    the new queue limits again when they dispatch those requests,
+ *    although such checkings are also done against the old queue limits
+ *    when submitting requests.
+ */
+int blk_rq_check_limits(struct request_queue *q, struct request *rq)
+{
+	if (rq->nr_sectors > q->max_sectors ||
+	    rq->data_len > q->max_hw_sectors << 9) {
+		printk(KERN_ERR "%s: over max size limit.\n", __func__);
+		return -EIO;
+	}
+
+	/*
+	 * queue's settings related to segment counting like q->bounce_pfn
+	 * may differ from that of other stacking queues.
+	 * Recalculate it to check the request correctly on this queue's
+	 * limitation.
+	 */
+	blk_recalc_rq_segments(rq);
+	if (rq->nr_phys_segments > q->max_phys_segments ||
+	    rq->nr_phys_segments > q->max_hw_segments) {
+		printk(KERN_ERR "%s: over max segments limit.\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_rq_check_limits);
+
+/**
+ * blk_insert_cloned_request - Helper for stacking drivers to submit a request
+ * @q:  the queue to submit the request
+ * @rq: the request being queued
+ */
+int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
+{
+	unsigned long flags;
+
+	if (blk_rq_check_limits(q, rq))
+		return -EIO;
+
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+	if (rq->rq_disk && rq->rq_disk->part0.make_it_fail &&
+	    should_fail(&fail_make_request, blk_rq_bytes(rq)))
+		return -EIO;
+#endif
+
+	spin_lock_irqsave(q->queue_lock, flags);
+
+	/*
+	 * Submitting request must be dequeued before calling this function
+	 * because it will be linked to another request_queue
+	 */
+	BUG_ON(blk_queued_rq(rq));
+
+	drive_stat_acct(rq, 1);
+	__elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 0);
+
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
+
+/**
+ * blkdev_dequeue_request - dequeue request and start timeout timer
+ * @req: request to dequeue
+ *
+ * Dequeue @req and start timeout timer on it.  This hands off the
+ * request to the driver.
+ *
+ * Block internal functions which don't want to start timer should
+ * call elv_dequeue_request().
+ */
+void blkdev_dequeue_request(struct request *req)
+{
+	elv_dequeue_request(req->q, req);
+
+	/*
+	 * We are now handing the request to the hardware, add the
+	 * timeout handler.
+	 */
+	blk_add_timer(req);
+}
+EXPORT_SYMBOL(blkdev_dequeue_request);
+
+static void blk_account_io_completion(struct request *req, unsigned int bytes)
+{
+	struct gendisk *disk = req->rq_disk;
+
+	if (!disk || !blk_do_io_stat(disk->queue))
+		return;
+
+	if (blk_fs_request(req)) {
+		const int rw = rq_data_dir(req);
+		struct hd_struct *part;
+		int cpu;
+
+		cpu = part_stat_lock();
+		part = disk_map_sector_rcu(req->rq_disk, req->sector);
+		part_stat_add(cpu, part, sectors[rw], bytes >> 9);
+		part_stat_unlock();
+	}
+}
+
+static void blk_account_io_done(struct request *req)
+{
+	struct gendisk *disk = req->rq_disk;
+
+	if (!disk || !blk_do_io_stat(disk->queue))
+		return;
+
+	/*
+	 * Account IO completion.  bar_rq isn't accounted as a normal
+	 * IO on queueing nor completion.  Accounting the containing
+	 * request is enough.
+	 */
+	if (blk_fs_request(req) && req != &req->q->bar_rq) {
+		unsigned long duration = jiffies - req->start_time;
+		const int rw = rq_data_dir(req);
+		struct hd_struct *part;
+		int cpu;
+
+		cpu = part_stat_lock();
+		part = disk_map_sector_rcu(disk, req->sector);
+
+		part_stat_inc(cpu, part, ios[rw]);
+		part_stat_add(cpu, part, ticks[rw], duration);
+		part_round_stats(cpu, part);
+		part_dec_in_flight(part);
+
+		part_stat_unlock();
+	}
+}
+
+/**
+ * __end_that_request_first - end I/O on a request
+ * @req:      the request being processed
+ * @error:    %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @req, and sets it up
+ *     for the next range of segments (if any) in the cluster.
+ *
+ * Return:
+ *     %0 - we are done with this request, call end_that_request_last()
+ *     %1 - still buffers pending for this request
+ **/
+static int __end_that_request_first(struct request *req, int error,
+				    int nr_bytes)
+{
+	int total_bytes, bio_nbytes, next_idx = 0;
+	struct bio *bio;
+
+	trace_block_rq_complete(req->q, req);
+
+	/*
+	 * for a REQ_TYPE_BLOCK_PC request, we want to carry any eventual
+	 * sense key with us all the way through
+	 */
+	if (!blk_pc_request(req))
+		req->errors = 0;
+
+	if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) {
+		printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu\n",
+				req->rq_disk ? req->rq_disk->disk_name : "?",
+				(unsigned long long)req->sector);
+	}
+
+	blk_account_io_completion(req, nr_bytes);
+
+	total_bytes = bio_nbytes = 0;
+	while ((bio = req->bio) != NULL) {
+		int nbytes;
+
+		if (nr_bytes >= bio->bi_size) {
+			req->bio = bio->bi_next;
+			nbytes = bio->bi_size;
+			req_bio_endio(req, bio, nbytes, error);
+			next_idx = 0;
+			bio_nbytes = 0;
+		} else {
+			int idx = bio->bi_idx + next_idx;
+
+			if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
+				blk_dump_rq_flags(req, "__end_that");
+				printk(KERN_ERR "%s: bio idx %d >= vcnt %d\n",
+				       __func__, bio->bi_idx, bio->bi_vcnt);
+				break;
+			}
+
+			nbytes = bio_iovec_idx(bio, idx)->bv_len;
+			BIO_BUG_ON(nbytes > bio->bi_size);
+
+			/*
+			 * not a complete bvec done
+			 */
+			if (unlikely(nbytes > nr_bytes)) {
+				bio_nbytes += nr_bytes;
+				total_bytes += nr_bytes;
+				break;
+			}
+
+			/*
+			 * advance to the next vector
+			 */
+			next_idx++;
+			bio_nbytes += nbytes;
+		}
+
+		total_bytes += nbytes;
+		nr_bytes -= nbytes;
+
+		bio = req->bio;
+		if (bio) {
+			/*
+			 * end more in this run, or just return 'not-done'
+			 */
+			if (unlikely(nr_bytes <= 0))
+				break;
+		}
+	}
+
+	/*
+	 * completely done
+	 */
+	if (!req->bio)
+		return 0;
+
+	/*
+	 * if the request wasn't completed, update state
+	 */
+	if (bio_nbytes) {
+		req_bio_endio(req, bio, bio_nbytes, error);
+		bio->bi_idx += next_idx;
+		bio_iovec(bio)->bv_offset += nr_bytes;
+		bio_iovec(bio)->bv_len -= nr_bytes;
+	}
+
+	blk_recalc_rq_sectors(req, total_bytes >> 9);
+	blk_recalc_rq_segments(req);
+	return 1;
+}
+
+/*
+ * queue lock must be held
+ */
+static void end_that_request_last(struct request *req, int error)
+{
+	if (blk_rq_tagged(req))
+		blk_queue_end_tag(req->q, req);
+
+	if (blk_queued_rq(req))
+		elv_dequeue_request(req->q, req);
+
+#ifndef DDE_LINUX
+	if (unlikely(laptop_mode) && blk_fs_request(req))
+		laptop_io_completion();
+#endif
+
+	blk_delete_timer(req);
+
+	blk_account_io_done(req);
+
+	if (req->end_io)
+		req->end_io(req, error);
+	else {
+		if (blk_bidi_rq(req))
+			__blk_put_request(req->next_rq->q, req->next_rq);
+
+		__blk_put_request(req->q, req);
+	}
+}
+
+/**
+ * blk_rq_bytes - Returns bytes left to complete in the entire request
+ * @rq: the request being processed
+ **/
+unsigned int blk_rq_bytes(struct request *rq)
+{
+	if (blk_fs_request(rq))
+		return rq->hard_nr_sectors << 9;
+
+	return rq->data_len;
+}
+EXPORT_SYMBOL_GPL(blk_rq_bytes);
+
+/**
+ * blk_rq_cur_bytes - Returns bytes left to complete in the current segment
+ * @rq: the request being processed
+ **/
+unsigned int blk_rq_cur_bytes(struct request *rq)
+{
+	if (blk_fs_request(rq))
+		return rq->current_nr_sectors << 9;
+
+	if (rq->bio)
+		return rq->bio->bi_size;
+
+	return rq->data_len;
+}
+EXPORT_SYMBOL_GPL(blk_rq_cur_bytes);
+
+/**
+ * end_request - end I/O on the current segment of the request
+ * @req:	the request being processed
+ * @uptodate:	error value or %0/%1 uptodate flag
+ *
+ * Description:
+ *     Ends I/O on the current segment of a request. If that is the only
+ *     remaining segment, the request is also completed and freed.
+ *
+ *     This is a remnant of how older block drivers handled I/O completions.
+ *     Modern drivers typically end I/O on the full request in one go, unless
+ *     they have a residual value to account for. For that case this function
+ *     isn't really useful, unless the residual just happens to be the
+ *     full current segment. In other words, don't use this function in new
+ *     code. Use blk_end_request() or __blk_end_request() to end a request.
+ **/
+void end_request(struct request *req, int uptodate)
+{
+	int error = 0;
+
+	if (uptodate <= 0)
+		error = uptodate ? uptodate : -EIO;
+
+	__blk_end_request(req, error, req->hard_cur_sectors << 9);
+}
+EXPORT_SYMBOL(end_request);
+
+static int end_that_request_data(struct request *rq, int error,
+				 unsigned int nr_bytes, unsigned int bidi_bytes)
+{
+	if (rq->bio) {
+		if (__end_that_request_first(rq, error, nr_bytes))
+			return 1;
+
+		/* Bidi request must be completed as a whole */
+		if (blk_bidi_rq(rq) &&
+		    __end_that_request_first(rq->next_rq, error, bidi_bytes))
+			return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * blk_end_io - Generic end_io function to complete a request.
+ * @rq:           the request being processed
+ * @error:        %0 for success, < %0 for error
+ * @nr_bytes:     number of bytes to complete @rq
+ * @bidi_bytes:   number of bytes to complete @rq->next_rq
+ * @drv_callback: function called between completion of bios in the request
+ *                and completion of the request.
+ *                If the callback returns non %0, this helper returns without
+ *                completion of the request.
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ *     %0 - we are done with this request
+ *     %1 - this request is not freed yet, it still has pending buffers.
+ **/
+static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
+		      unsigned int bidi_bytes,
+		      int (drv_callback)(struct request *))
+{
+	struct request_queue *q = rq->q;
+	unsigned long flags = 0UL;
+
+	if (end_that_request_data(rq, error, nr_bytes, bidi_bytes))
+		return 1;
+
+	/* Special feature for tricky drivers */
+	if (drv_callback && drv_callback(rq))
+		return 1;
+
+#ifndef DDE_LINUX
+	add_disk_randomness(rq->rq_disk);
+#endif
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	end_that_request_last(rq, error);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+	return 0;
+}
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq:       the request being processed
+ * @error:    %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
+ **/
+int blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+	return blk_end_io(rq, error, nr_bytes, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(blk_end_request);
+
+/**
+ * __blk_end_request - Helper function for drivers to complete the request.
+ * @rq:       the request being processed
+ * @error:    %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Must be called with queue lock held unlike blk_end_request().
+ *
+ * Return:
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
+ **/
+int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+	if (rq->bio && __end_that_request_first(rq, error, nr_bytes))
+		return 1;
+
+#ifndef DDE_LINUX
+	add_disk_randomness(rq->rq_disk);
+#endif
+
+	end_that_request_last(rq, error);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__blk_end_request);
+
+/**
+ * blk_end_bidi_request - Helper function for drivers to complete bidi request.
+ * @rq:         the bidi request being processed
+ * @error:      %0 for success, < %0 for error
+ * @nr_bytes:   number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ *
+ * Return:
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
+ **/
+int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes,
+			 unsigned int bidi_bytes)
+{
+	return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL);
+}
+EXPORT_SYMBOL_GPL(blk_end_bidi_request);
+
+/**
+ * blk_update_request - Special helper function for request stacking drivers
+ * @rq:           the request being processed
+ * @error:        %0 for success, < %0 for error
+ * @nr_bytes:     number of bytes to complete @rq
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq, but doesn't complete
+ *     the request structure even if @rq doesn't have leftover.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ *     This special helper function is only for request stacking drivers
+ *     (e.g. request-based dm) so that they can handle partial completion.
+ *     Actual device drivers should use blk_end_request instead.
+ */
+void blk_update_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+	if (!end_that_request_data(rq, error, nr_bytes, 0)) {
+		/*
+		 * These members are not updated in end_that_request_data()
+		 * when all bios are completed.
+		 * Update them so that the request stacking driver can find
+		 * how many bytes remain in the request later.
+		 */
+		rq->nr_sectors = rq->hard_nr_sectors = 0;
+		rq->current_nr_sectors = rq->hard_cur_sectors = 0;
+	}
+}
+EXPORT_SYMBOL_GPL(blk_update_request);
+
+/**
+ * blk_end_request_callback - Special helper function for tricky drivers
+ * @rq:           the request being processed
+ * @error:        %0 for success, < %0 for error
+ * @nr_bytes:     number of bytes to complete
+ * @drv_callback: function called between completion of bios in the request
+ *                and completion of the request.
+ *                If the callback returns non %0, this helper returns without
+ *                completion of the request.
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ *     This special helper function is used only for existing tricky drivers.
+ *     (e.g. cdrom_newpc_intr() of ide-cd)
+ *     This interface will be removed when such drivers are rewritten.
+ *     Don't use this interface in other places anymore.
+ *
+ * Return:
+ *     %0 - we are done with this request
+ *     %1 - this request is not freed yet.
+ *          this request still has pending buffers or
+ *          the driver doesn't want to finish this request yet.
+ **/
+int blk_end_request_callback(struct request *rq, int error,
+			     unsigned int nr_bytes,
+			     int (drv_callback)(struct request *))
+{
+	return blk_end_io(rq, error, nr_bytes, 0, drv_callback);
+}
+EXPORT_SYMBOL_GPL(blk_end_request_callback);
+
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+		     struct bio *bio)
+{
+	/* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
+	   we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
+	rq->cmd_flags |= (bio->bi_rw & 3);
+
+	if (bio_has_data(bio)) {
+		rq->nr_phys_segments = bio_phys_segments(q, bio);
+		rq->buffer = bio_data(bio);
+	}
+	rq->current_nr_sectors = bio_cur_sectors(bio);
+	rq->hard_cur_sectors = rq->current_nr_sectors;
+	rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio);
+	rq->data_len = bio->bi_size;
+
+	rq->bio = rq->biotail = bio;
+
+	if (bio->bi_bdev)
+		rq->rq_disk = bio->bi_bdev->bd_disk;
+}
+
+/**
+ * blk_lld_busy - Check if underlying low-level drivers of a device are busy
+ * @q : the queue of the device being checked
+ *
+ * Description:
+ *    Check if underlying low-level drivers of a device are busy.
+ *    If the drivers want to export their busy state, they must set own
+ *    exporting function using blk_queue_lld_busy() first.
+ *
+ *    Basically, this function is used only by request stacking drivers
+ *    to stop dispatching requests to underlying devices when underlying
+ *    devices are busy.  This behavior helps more I/O merging on the queue
+ *    of the request stacking driver and prevents I/O throughput regression
+ *    on burst I/O load.
+ *
+ * Return:
+ *    0 - Not busy (The request stacking driver should dispatch request)
+ *    1 - Busy (The request stacking driver should stop dispatching request)
+ */
+int blk_lld_busy(struct request_queue *q)
+{
+	if (q->lld_busy_fn)
+		return q->lld_busy_fn(q);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_lld_busy);
+
+int kblockd_schedule_work(struct request_queue *q, struct work_struct *work)
+{
+	return queue_work(kblockd_workqueue, work);
+}
+EXPORT_SYMBOL(kblockd_schedule_work);
+
+int __init blk_dev_init(void)
+{
+	kblockd_workqueue = create_workqueue("kblockd");
+	if (!kblockd_workqueue)
+		panic("Failed to create kblockd\n");
+
+	request_cachep = kmem_cache_create("blkdev_requests",
+			sizeof(struct request), 0, SLAB_PANIC, NULL);
+
+	blk_requestq_cachep = kmem_cache_create("blkdev_queue",
+			sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
+
+	return 0;
+}
+
diff --git a/libdde_linux26/lib/src/block/.svn/text-base/blk.h.svn-base b/libdde_linux26/lib/src/block/.svn/text-base/blk.h.svn-base
new file mode 100644
index 00000000..0dce92c3
--- /dev/null
+++ b/libdde_linux26/lib/src/block/.svn/text-base/blk.h.svn-base
@@ -0,0 +1,119 @@
+#ifndef BLK_INTERNAL_H
+#define BLK_INTERNAL_H
+
+/* Amount of time in which a process may batch requests */
+#define BLK_BATCH_TIME	(HZ/50UL)
+
+/* Number of requests a "batching" process may submit */
+#define BLK_BATCH_REQ	32
+
+extern struct kmem_cache *blk_requestq_cachep;
+extern struct kobj_type blk_queue_ktype;
+
+void init_request_from_bio(struct request *req, struct bio *bio);
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+			struct bio *bio);
+void __blk_queue_free_tags(struct request_queue *q);
+
+void blk_unplug_work(struct work_struct *work);
+void blk_unplug_timeout(unsigned long data);
+void blk_rq_timed_out_timer(unsigned long data);
+void blk_delete_timer(struct request *);
+void blk_add_timer(struct request *);
+void __generic_unplug_device(struct request_queue *);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+	REQ_ATOM_COMPLETE = 0,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them suceeds
+ */
+static inline int blk_mark_rq_complete(struct request *rq)
+{
+	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_complete(struct request *rq)
+{
+	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+				const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+	return 0;
+}
+#endif
+
+struct io_context *current_io_context(gfp_t gfp_flags, int node);
+
+int ll_back_merge_fn(struct request_queue *q, struct request *req,
+		     struct bio *bio);
+int ll_front_merge_fn(struct request_queue *q, struct request *req, 
+		      struct bio *bio);
+int attempt_back_merge(struct request_queue *q, struct request *rq);
+int attempt_front_merge(struct request_queue *q, struct request *rq);
+void blk_recalc_rq_segments(struct request *rq);
+void blk_recalc_rq_sectors(struct request *rq, int nsect);
+
+void blk_queue_congestion_threshold(struct request_queue *q);
+
+int blk_dev_init(void);
+
+/*
+ * Return the threshold (number of used requests) at which the queue is
+ * considered to be congested.  It include a little hysteresis to keep the
+ * context switch rate down.
+ */
+static inline int queue_congestion_on_threshold(struct request_queue *q)
+{
+	return q->nr_congestion_on;
+}
+
+/*
+ * The threshold at which a queue is considered to be uncongested
+ */
+static inline int queue_congestion_off_threshold(struct request_queue *q)
+{
+	return q->nr_congestion_off;
+}
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+#define rq_for_each_integrity_segment(bvl, _rq, _iter)		\
+	__rq_for_each_bio(_iter.bio, _rq)			\
+		bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
+
+#endif /* BLK_DEV_INTEGRITY */
+
+static inline int blk_cpu_to_group(int cpu)
+{
+#ifdef CONFIG_SCHED_MC
+	const struct cpumask *mask = cpu_coregroup_mask(cpu);
+	return cpumask_first(mask);
+#elif defined(CONFIG_SCHED_SMT)
+	return first_cpu(per_cpu(cpu_sibling_map, cpu));
+#else
+	return cpu;
+#endif
+}
+
+static inline int blk_do_io_stat(struct request_queue *q)
+{
+	if (q)
+		return blk_queue_io_stat(q);
+
+	return 0;
+}
+
+#endif
diff --git a/libdde_linux26/lib/src/block/.svn/text-base/genhd.c.svn-base b/libdde_linux26/lib/src/block/.svn/text-base/genhd.c.svn-base
new file mode 100644
index 00000000..921cebff
--- /dev/null
+++ b/libdde_linux26/lib/src/block/.svn/text-base/genhd.c.svn-base
@@ -0,0 +1,1248 @@
+/*
+ *  gendisk handling
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/kobj_map.h>
+#include <linux/buffer_head.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+
+#include "blk.h"
+#ifdef DDE_LINUX
+#include "local.h"
+#endif
+
+static DEFINE_MUTEX(block_class_lock);
+#ifndef CONFIG_SYSFS_DEPRECATED
+struct kobject *block_depr;
+#endif
+
+/* for extended dynamic devt allocation, currently only one major is used */
+#define MAX_EXT_DEVT		(1 << MINORBITS)
+
+/* For extended devt allocation.  ext_devt_mutex prevents look up
+ * results from going away underneath its user.
+ */
+static DEFINE_MUTEX(ext_devt_mutex);
+static DEFINE_IDR(ext_devt_idr);
+
+static struct device_type disk_type;
+
+/**
+ * disk_get_part - get partition
+ * @disk: disk to look partition from
+ * @partno: partition number
+ *
+ * Look for partition @partno from @disk.  If found, increment
+ * reference count and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Pointer to the found partition on success, NULL if not found.
+ */
+struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
+{
+	struct hd_struct *part = NULL;
+	struct disk_part_tbl *ptbl;
+
+	if (unlikely(partno < 0))
+		return NULL;
+
+	rcu_read_lock();
+
+	ptbl = rcu_dereference(disk->part_tbl);
+	if (likely(partno < ptbl->len)) {
+		part = rcu_dereference(ptbl->part[partno]);
+		if (part)
+			get_device(part_to_dev(part));
+	}
+
+	rcu_read_unlock();
+
+	return part;
+}
+EXPORT_SYMBOL_GPL(disk_get_part);
+
+/**
+ * disk_part_iter_init - initialize partition iterator
+ * @piter: iterator to initialize
+ * @disk: disk to iterate over
+ * @flags: DISK_PITER_* flags
+ *
+ * Initialize @piter so that it iterates over partitions of @disk.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
+			  unsigned int flags)
+{
+	struct disk_part_tbl *ptbl;
+
+	rcu_read_lock();
+	ptbl = rcu_dereference(disk->part_tbl);
+
+	piter->disk = disk;
+	piter->part = NULL;
+
+	if (flags & DISK_PITER_REVERSE)
+		piter->idx = ptbl->len - 1;
+	else if (flags & DISK_PITER_INCL_PART0)
+		piter->idx = 0;
+	else
+		piter->idx = 1;
+
+	piter->flags = flags;
+
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_init);
+
+/**
+ * disk_part_iter_next - proceed iterator to the next partition and return it
+ * @piter: iterator of interest
+ *
+ * Proceed @piter to the next partition and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
+{
+	struct disk_part_tbl *ptbl;
+	int inc, end;
+
+	/* put the last partition */
+	disk_put_part(piter->part);
+	piter->part = NULL;
+
+	/* get part_tbl */
+	rcu_read_lock();
+	ptbl = rcu_dereference(piter->disk->part_tbl);
+
+	/* determine iteration parameters */
+	if (piter->flags & DISK_PITER_REVERSE) {
+		inc = -1;
+		if (piter->flags & DISK_PITER_INCL_PART0)
+			end = -1;
+		else
+			end = 0;
+	} else {
+		inc = 1;
+		end = ptbl->len;
+	}
+
+	/* iterate to the next partition */
+	for (; piter->idx != end; piter->idx += inc) {
+		struct hd_struct *part;
+
+		part = rcu_dereference(ptbl->part[piter->idx]);
+		if (!part)
+			continue;
+		if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
+			continue;
+
+		get_device(part_to_dev(part));
+		piter->part = part;
+		piter->idx += inc;
+		break;
+	}
+
+	rcu_read_unlock();
+
+	return piter->part;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_next);
+
+/**
+ * disk_part_iter_exit - finish up partition iteration
+ * @piter: iter of interest
+ *
+ * Called when iteration is over.  Cleans up @piter.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_exit(struct disk_part_iter *piter)
+{
+	disk_put_part(piter->part);
+	piter->part = NULL;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_exit);
+
+static inline int sector_in_part(struct hd_struct *part, sector_t sector)
+{
+	return part->start_sect <= sector &&
+		sector < part->start_sect + part->nr_sects;
+}
+
+/**
+ * disk_map_sector_rcu - map sector to partition
+ * @disk: gendisk of interest
+ * @sector: sector to map
+ *
+ * Find out which partition @sector maps to on @disk.  This is
+ * primarily used for stats accounting.
+ *
+ * CONTEXT:
+ * RCU read locked.  The returned partition pointer is valid only
+ * while preemption is disabled.
+ *
+ * RETURNS:
+ * Found partition on success, part0 is returned if no partition matches
+ */
+struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
+{
+	struct disk_part_tbl *ptbl;
+	struct hd_struct *part;
+	int i;
+
+	ptbl = rcu_dereference(disk->part_tbl);
+
+	part = rcu_dereference(ptbl->last_lookup);
+	if (part && sector_in_part(part, sector))
+		return part;
+
+	for (i = 1; i < ptbl->len; i++) {
+		part = rcu_dereference(ptbl->part[i]);
+
+		if (part && sector_in_part(part, sector)) {
+			rcu_assign_pointer(ptbl->last_lookup, part);
+			return part;
+		}
+	}
+	return &disk->part0;
+}
+EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
+
+/*
+ * Can be deleted altogether. Later.
+ *
+ */
+static struct blk_major_name {
+	struct blk_major_name *next;
+	int major;
+	char name[16];
+} *major_names[BLKDEV_MAJOR_HASH_SIZE];
+
+/* index in the above - for now: assume no multimajor ranges */
+static inline int major_to_index(int major)
+{
+	return major % BLKDEV_MAJOR_HASH_SIZE;
+}
+
+#ifdef CONFIG_PROC_FS
+void blkdev_show(struct seq_file *seqf, off_t offset)
+{
+	struct blk_major_name *dp;
+
+	if (offset < BLKDEV_MAJOR_HASH_SIZE) {
+		mutex_lock(&block_class_lock);
+		for (dp = major_names[offset]; dp; dp = dp->next)
+			seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
+		mutex_unlock(&block_class_lock);
+	}
+}
+#endif /* CONFIG_PROC_FS */
+
+/**
+ * register_blkdev - register a new block device
+ *
+ * @major: the requested major device number [1..255]. If @major=0, try to
+ *         allocate any unused major number.
+ * @name: the name of the new block device as a zero terminated string
+ *
+ * The @name must be unique within the system.
+ *
+ * The return value depends on the @major input parameter.
+ *  - if a major device number was requested in range [1..255] then the
+ *    function returns zero on success, or a negative error code
+ *  - if any unused major number was requested with @major=0 parameter
+ *    then the return value is the allocated major number in range
+ *    [1..255] or a negative error code otherwise
+ */
+int register_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n, *p;
+	int index, ret = 0;
+
+	mutex_lock(&block_class_lock);
+
+	/* temporary */
+	if (major == 0) {
+		for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
+			if (major_names[index] == NULL)
+				break;
+		}
+
+		if (index == 0) {
+			printk("register_blkdev: failed to get major for %s\n",
+			       name);
+			ret = -EBUSY;
+			goto out;
+		}
+		major = index;
+		ret = major;
+	}
+
+	p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
+	if (p == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	p->major = major;
+	strlcpy(p->name, name, sizeof(p->name));
+	p->next = NULL;
+	index = major_to_index(major);
+
+	for (n = &major_names[index]; *n; n = &(*n)->next) {
+		if ((*n)->major == major)
+			break;
+	}
+	if (!*n)
+		*n = p;
+	else
+		ret = -EBUSY;
+
+	if (ret < 0) {
+		printk("register_blkdev: cannot get major %d for %s\n",
+		       major, name);
+		kfree(p);
+	}
+out:
+	mutex_unlock(&block_class_lock);
+	return ret;
+}
+
+EXPORT_SYMBOL(register_blkdev);
+
+void unregister_blkdev(unsigned int major, const char *name)
+{
+	struct blk_major_name **n;
+	struct blk_major_name *p = NULL;
+	int index = major_to_index(major);
+
+	mutex_lock(&block_class_lock);
+	for (n = &major_names[index]; *n; n = &(*n)->next)
+		if ((*n)->major == major)
+			break;
+	if (!*n || strcmp((*n)->name, name)) {
+		WARN_ON(1);
+	} else {
+		p = *n;
+		*n = p->next;
+	}
+	mutex_unlock(&block_class_lock);
+	kfree(p);
+}
+
+EXPORT_SYMBOL(unregister_blkdev);
+
+static struct kobj_map *bdev_map;
+
+/**
+ * blk_mangle_minor - scatter minor numbers apart
+ * @minor: minor number to mangle
+ *
+ * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
+ * is enabled.  Mangling twice gives the original value.
+ *
+ * RETURNS:
+ * Mangled value.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+static int blk_mangle_minor(int minor)
+{
+#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
+	int i;
+
+	for (i = 0; i < MINORBITS / 2; i++) {
+		int low = minor & (1 << i);
+		int high = minor & (1 << (MINORBITS - 1 - i));
+		int distance = MINORBITS - 1 - 2 * i;
+
+		minor ^= low | high;	/* clear both bits */
+		low <<= distance;	/* swap the positions */
+		high >>= distance;
+		minor |= low | high;	/* and set */
+	}
+#endif
+	return minor;
+}
+
+/**
+ * blk_alloc_devt - allocate a dev_t for a partition
+ * @part: partition to allocate dev_t for
+ * @devt: out parameter for resulting dev_t
+ *
+ * Allocate a dev_t for block device.
+ *
+ * RETURNS:
+ * 0 on success, allocated dev_t is returned in *@devt.  -errno on
+ * failure.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
+{
+	struct gendisk *disk = part_to_disk(part);
+	int idx, rc;
+
+	/* in consecutive minor range? */
+	if (part->partno < disk->minors) {
+		*devt = MKDEV(disk->major, disk->first_minor + part->partno);
+		return 0;
+	}
+
+	/* allocate ext devt */
+	do {
+		if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL))
+			return -ENOMEM;
+		rc = idr_get_new(&ext_devt_idr, part, &idx);
+	} while (rc == -EAGAIN);
+
+	if (rc)
+		return rc;
+
+	if (idx > MAX_EXT_DEVT) {
+		idr_remove(&ext_devt_idr, idx);
+		return -EBUSY;
+	}
+
+	*devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
+	return 0;
+}
+
+/**
+ * blk_free_devt - free a dev_t
+ * @devt: dev_t to free
+ *
+ * Free @devt which was allocated using blk_alloc_devt().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void blk_free_devt(dev_t devt)
+{
+	might_sleep();
+
+	if (devt == MKDEV(0, 0))
+		return;
+
+	if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
+		mutex_lock(&ext_devt_mutex);
+		idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+		mutex_unlock(&ext_devt_mutex);
+	}
+}
+
+static char *bdevt_str(dev_t devt, char *buf)
+{
+	if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
+		char tbuf[BDEVT_SIZE];
+		snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
+		snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
+	} else
+		snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
+
+	return buf;
+}
+
+/*
+ * Register device numbers dev..(dev+range-1)
+ * range must be nonzero
+ * The hash chain is sorted on range, so that subranges can override.
+ */
+void blk_register_region(dev_t devt, unsigned long range, struct module *module,
+			 struct kobject *(*probe)(dev_t, int *, void *),
+			 int (*lock)(dev_t, void *), void *data)
+{
+	kobj_map(bdev_map, devt, range, module, probe, lock, data);
+}
+
+EXPORT_SYMBOL(blk_register_region);
+
+void blk_unregister_region(dev_t devt, unsigned long range)
+{
+	kobj_unmap(bdev_map, devt, range);
+}
+
+EXPORT_SYMBOL(blk_unregister_region);
+
+static struct kobject *exact_match(dev_t devt, int *partno, void *data)
+{
+	struct gendisk *p = data;
+
+	return &disk_to_dev(p)->kobj;
+}
+
+static int exact_lock(dev_t devt, void *data)
+{
+	struct gendisk *p = data;
+
+	if (!get_disk(p))
+		return -1;
+	return 0;
+}
+
+#ifndef DDE_LINUX
+/**
+ * add_disk - add partitioning information to kernel list
+ * @disk: per-device partitioning information
+ *
+ * This function registers the partitioning information in @disk
+ * with the kernel.
+ *
+ * FIXME: error handling
+ */
+void add_disk(struct gendisk *disk)
+{
+	struct backing_dev_info *bdi;
+	dev_t devt;
+	int retval;
+
+	/* minors == 0 indicates to use ext devt from part0 and should
+	 * be accompanied with EXT_DEVT flag.  Make sure all
+	 * parameters make sense.
+	 */
+	WARN_ON(disk->minors && !(disk->major || disk->first_minor));
+	WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
+
+	disk->flags |= GENHD_FL_UP;
+
+	retval = blk_alloc_devt(&disk->part0, &devt);
+	if (retval) {
+		WARN_ON(1);
+		return;
+	}
+	disk_to_dev(disk)->devt = devt;
+
+	/* ->major and ->first_minor aren't supposed to be
+	 * dereferenced from here on, but set them just in case.
+	 */
+	disk->major = MAJOR(devt);
+	disk->first_minor = MINOR(devt);
+
+	blk_register_region(disk_devt(disk), disk->minors, NULL,
+			    exact_match, exact_lock, disk);
+	register_disk(disk);
+	blk_register_queue(disk);
+
+	bdi = &disk->queue->backing_dev_info;
+	bdi_register_dev(bdi, disk_devt(disk));
+	retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
+				   "bdi");
+	WARN_ON(retval);
+}
+
+EXPORT_SYMBOL(add_disk);
+EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
+#endif
+
+void unlink_gendisk(struct gendisk *disk)
+{
+	sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
+	bdi_unregister(&disk->queue->backing_dev_info);
+	blk_unregister_queue(disk);
+	blk_unregister_region(disk_devt(disk), disk->minors);
+}
+
+#ifndef DDE_LINUX
+/**
+ * get_gendisk - get partitioning information for a given device
+ * @devt: device to get partitioning information for
+ * @partno: returned partition index
+ *
+ * This function gets the structure containing partitioning
+ * information for the given device @devt.
+ */
+struct gendisk *get_gendisk(dev_t devt, int *partno)
+{
+	struct gendisk *disk = NULL;
+
+	if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
+		struct kobject *kobj;
+
+		kobj = kobj_lookup(bdev_map, devt, partno);
+		if (kobj)
+			disk = dev_to_disk(kobj_to_dev(kobj));
+	} else {
+		struct hd_struct *part;
+
+		mutex_lock(&ext_devt_mutex);
+		part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+		if (part && get_disk(part_to_disk(part))) {
+			*partno = part->partno;
+			disk = part_to_disk(part);
+		}
+		mutex_unlock(&ext_devt_mutex);
+	}
+
+	return disk;
+}
+#endif
+
+/**
+ * bdget_disk - do bdget() by gendisk and partition number
+ * @disk: gendisk of interest
+ * @partno: partition number
+ *
+ * Find partition @partno from @disk, do bdget() on it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Resulting block_device on success, NULL on failure.
+ */
+struct block_device *bdget_disk(struct gendisk *disk, int partno)
+{
+	struct hd_struct *part;
+	struct block_device *bdev = NULL;
+
+	part = disk_get_part(disk, partno);
+	if (part)
+		bdev = bdget(part_devt(part));
+	disk_put_part(part);
+
+	return bdev;
+}
+EXPORT_SYMBOL(bdget_disk);
+
+/*
+ * print a full list of all partitions - intended for places where the root
+ * filesystem can't be mounted and thus to give the victim some idea of what
+ * went wrong
+ */
+void __init printk_all_partitions(void)
+{
+	struct class_dev_iter iter;
+	struct device *dev;
+
+	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+	while ((dev = class_dev_iter_next(&iter))) {
+		struct gendisk *disk = dev_to_disk(dev);
+		struct disk_part_iter piter;
+		struct hd_struct *part;
+		char name_buf[BDEVNAME_SIZE];
+		char devt_buf[BDEVT_SIZE];
+
+		/*
+		 * Don't show empty devices or things that have been
+		 * surpressed
+		 */
+		if (get_capacity(disk) == 0 ||
+		    (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
+			continue;
+
+		/*
+		 * Note, unlike /proc/partitions, I am showing the
+		 * numbers in hex - the same format as the root=
+		 * option takes.
+		 */
+		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+		while ((part = disk_part_iter_next(&piter))) {
+			bool is_part0 = part == &disk->part0;
+
+			printk("%s%s %10llu %s", is_part0 ? "" : "  ",
+			       bdevt_str(part_devt(part), devt_buf),
+			       (unsigned long long)part->nr_sects >> 1,
+			       disk_name(disk, part->partno, name_buf));
+			if (is_part0) {
+				if (disk->driverfs_dev != NULL &&
+				    disk->driverfs_dev->driver != NULL)
+					printk(" driver: %s\n",
+					      disk->driverfs_dev->driver->name);
+				else
+					printk(" (driver?)\n");
+			} else
+				printk("\n");
+		}
+		disk_part_iter_exit(&piter);
+	}
+	class_dev_iter_exit(&iter);
+}
+
+#ifdef CONFIG_PROC_FS
+/* iterator */
+static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
+{
+	loff_t skip = *pos;
+	struct class_dev_iter *iter;
+	struct device *dev;
+
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return ERR_PTR(-ENOMEM);
+
+	seqf->private = iter;
+	class_dev_iter_init(iter, &block_class, NULL, &disk_type);
+	do {
+		dev = class_dev_iter_next(iter);
+		if (!dev)
+			return NULL;
+	} while (skip--);
+
+	return dev_to_disk(dev);
+}
+
+static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
+{
+	struct device *dev;
+
+	(*pos)++;
+	dev = class_dev_iter_next(seqf->private);
+	if (dev)
+		return dev_to_disk(dev);
+
+	return NULL;
+}
+
+static void disk_seqf_stop(struct seq_file *seqf, void *v)
+{
+	struct class_dev_iter *iter = seqf->private;
+
+	/* stop is called even after start failed :-( */
+	if (iter) {
+		class_dev_iter_exit(iter);
+		kfree(iter);
+	}
+}
+
+static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
+{
+	static void *p;
+
+	p = disk_seqf_start(seqf, pos);
+	if (!IS_ERR(p) && p && !*pos)
+		seq_puts(seqf, "major minor  #blocks  name\n\n");
+	return p;
+}
+
+static int show_partition(struct seq_file *seqf, void *v)
+{
+	struct gendisk *sgp = v;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+	char buf[BDEVNAME_SIZE];
+
+	/* Don't show non-partitionable removeable devices or empty devices */
+	if (!get_capacity(sgp) || (!disk_partitionable(sgp) &&
+				   (sgp->flags & GENHD_FL_REMOVABLE)))
+		return 0;
+	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
+		return 0;
+
+	/* show the full disk and all non-0 size partitions of it */
+	disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
+	while ((part = disk_part_iter_next(&piter)))
+		seq_printf(seqf, "%4d  %7d %10llu %s\n",
+			   MAJOR(part_devt(part)), MINOR(part_devt(part)),
+			   (unsigned long long)part->nr_sects >> 1,
+			   disk_name(sgp, part->partno, buf));
+	disk_part_iter_exit(&piter);
+
+	return 0;
+}
+
+static const struct seq_operations partitions_op = {
+	.start	= show_partition_start,
+	.next	= disk_seqf_next,
+	.stop	= disk_seqf_stop,
+	.show	= show_partition
+};
+
+static int partitions_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &partitions_op);
+}
+
+static const struct file_operations proc_partitions_operations = {
+	.open		= partitions_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+#endif
+
+
+static struct kobject *base_probe(dev_t devt, int *partno, void *data)
+{
+	if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
+		/* Make old-style 2.4 aliases work */
+		request_module("block-major-%d", MAJOR(devt));
+	return NULL;
+}
+
+static int __init genhd_device_init(void)
+{
+	int error;
+
+	block_class.dev_kobj = sysfs_dev_block_kobj;
+	error = class_register(&block_class);
+	if (unlikely(error))
+		return error;
+	bdev_map = kobj_map_init(base_probe, &block_class_lock);
+	blk_dev_init();
+
+	register_blkdev(BLOCK_EXT_MAJOR, "blkext");
+
+#ifndef CONFIG_SYSFS_DEPRECATED
+	/* create top-level block dir */
+	block_depr = kobject_create_and_add("block", NULL);
+#endif
+	return 0;
+}
+
+subsys_initcall(genhd_device_init);
+
+static ssize_t disk_range_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%d\n", disk->minors);
+}
+
+static ssize_t disk_ext_range_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%d\n", disk_max_parts(disk));
+}
+
+static ssize_t disk_removable_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%d\n",
+		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+}
+
+static ssize_t disk_ro_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
+}
+
+static ssize_t disk_capability_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	return sprintf(buf, "%x\n", disk->flags);
+}
+
+static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
+static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
+static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
+static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
+static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
+static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+static struct device_attribute dev_attr_fail =
+	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+static struct device_attribute dev_attr_fail_timeout =
+	__ATTR(io-timeout-fail,  S_IRUGO|S_IWUSR, part_timeout_show,
+		part_timeout_store);
+#endif
+
+static struct attribute *disk_attrs[] = {
+	&dev_attr_range.attr,
+	&dev_attr_ext_range.attr,
+	&dev_attr_removable.attr,
+	&dev_attr_ro.attr,
+	&dev_attr_size.attr,
+	&dev_attr_capability.attr,
+	&dev_attr_stat.attr,
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+	&dev_attr_fail.attr,
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+	&dev_attr_fail_timeout.attr,
+#endif
+	NULL
+};
+
+static struct attribute_group disk_attr_group = {
+	.attrs = disk_attrs,
+};
+
+static struct attribute_group *disk_attr_groups[] = {
+	&disk_attr_group,
+	NULL
+};
+
+static void disk_free_ptbl_rcu_cb(struct rcu_head *head)
+{
+	struct disk_part_tbl *ptbl =
+		container_of(head, struct disk_part_tbl, rcu_head);
+
+	kfree(ptbl);
+}
+
+/**
+ * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
+ * @disk: disk to replace part_tbl for
+ * @new_ptbl: new part_tbl to install
+ *
+ * Replace disk->part_tbl with @new_ptbl in RCU-safe way.  The
+ * original ptbl is freed using RCU callback.
+ *
+ * LOCKING:
+ * Matching bd_mutx locked.
+ */
+static void disk_replace_part_tbl(struct gendisk *disk,
+				  struct disk_part_tbl *new_ptbl)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+
+	rcu_assign_pointer(disk->part_tbl, new_ptbl);
+
+	if (old_ptbl) {
+		rcu_assign_pointer(old_ptbl->last_lookup, NULL);
+#ifndef DDE_LINUX
+		call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb);
+#else
+		disk_free_ptbl_rcu_cb(&old_ptbl->rcu_head);
+#endif
+	}
+}
+
+/**
+ * disk_expand_part_tbl - expand disk->part_tbl
+ * @disk: disk to expand part_tbl for
+ * @partno: expand such that this partno can fit in
+ *
+ * Expand disk->part_tbl such that @partno can fit in.  disk->part_tbl
+ * uses RCU to allow unlocked dereferencing for stats and other stuff.
+ *
+ * LOCKING:
+ * Matching bd_mutex locked, might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int disk_expand_part_tbl(struct gendisk *disk, int partno)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+	struct disk_part_tbl *new_ptbl;
+	int len = old_ptbl ? old_ptbl->len : 0;
+	int target = partno + 1;
+	size_t size;
+	int i;
+
+	/* disk_max_parts() is zero during initialization, ignore if so */
+	if (disk_max_parts(disk) && target > disk_max_parts(disk))
+		return -EINVAL;
+
+	if (target <= len)
+		return 0;
+
+	size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
+	new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
+	if (!new_ptbl)
+		return -ENOMEM;
+
+	INIT_RCU_HEAD(&new_ptbl->rcu_head);
+	new_ptbl->len = target;
+
+	for (i = 0; i < len; i++)
+		rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
+
+	disk_replace_part_tbl(disk, new_ptbl);
+	return 0;
+}
+
+static void disk_release(struct device *dev)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	kfree(disk->random);
+	disk_replace_part_tbl(disk, NULL);
+	free_part_stats(&disk->part0);
+	kfree(disk);
+}
+struct class block_class = {
+	.name		= "block",
+};
+
+static struct device_type disk_type = {
+	.name		= "disk",
+	.groups		= disk_attr_groups,
+	.release	= disk_release,
+};
+
+#ifdef CONFIG_PROC_FS
+/*
+ * aggregate disk stat collector.  Uses the same stats that the sysfs
+ * entries do, above, but makes them available through one seq_file.
+ *
+ * The output looks suspiciously like /proc/partitions with a bunch of
+ * extra fields.
+ */
+static int diskstats_show(struct seq_file *seqf, void *v)
+{
+	struct gendisk *gp = v;
+	struct disk_part_iter piter;
+	struct hd_struct *hd;
+	char buf[BDEVNAME_SIZE];
+	int cpu;
+
+	/*
+	if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
+		seq_puts(seqf,	"major minor name"
+				"     rio rmerge rsect ruse wio wmerge "
+				"wsect wuse running use aveq"
+				"\n\n");
+	*/
+ 
+	disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0);
+	while ((hd = disk_part_iter_next(&piter))) {
+		cpu = part_stat_lock();
+		part_round_stats(cpu, hd);
+		part_stat_unlock();
+		seq_printf(seqf, "%4d %7d %s %lu %lu %llu "
+			   "%u %lu %lu %llu %u %u %u %u\n",
+			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
+			   disk_name(gp, hd->partno, buf),
+			   part_stat_read(hd, ios[0]),
+			   part_stat_read(hd, merges[0]),
+			   (unsigned long long)part_stat_read(hd, sectors[0]),
+			   jiffies_to_msecs(part_stat_read(hd, ticks[0])),
+			   part_stat_read(hd, ios[1]),
+			   part_stat_read(hd, merges[1]),
+			   (unsigned long long)part_stat_read(hd, sectors[1]),
+			   jiffies_to_msecs(part_stat_read(hd, ticks[1])),
+			   hd->in_flight,
+			   jiffies_to_msecs(part_stat_read(hd, io_ticks)),
+			   jiffies_to_msecs(part_stat_read(hd, time_in_queue))
+			);
+	}
+	disk_part_iter_exit(&piter);
+ 
+	return 0;
+}
+
+static const struct seq_operations diskstats_op = {
+	.start	= disk_seqf_start,
+	.next	= disk_seqf_next,
+	.stop	= disk_seqf_stop,
+	.show	= diskstats_show
+};
+
+static int diskstats_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &diskstats_op);
+}
+
+static const struct file_operations proc_diskstats_operations = {
+	.open		= diskstats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init proc_genhd_init(void)
+{
+	proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
+	proc_create("partitions", 0, NULL, &proc_partitions_operations);
+	return 0;
+}
+module_init(proc_genhd_init);
+#endif /* CONFIG_PROC_FS */
+
+static void media_change_notify_thread(struct work_struct *work)
+{
+	struct gendisk *gd = container_of(work, struct gendisk, async_notify);
+	char event[] = "MEDIA_CHANGE=1";
+	char *envp[] = { event, NULL };
+
+	/*
+	 * set enviroment vars to indicate which event this is for
+	 * so that user space will know to go check the media status.
+	 */
+	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
+	put_device(gd->driverfs_dev);
+}
+
+#if 0
+void genhd_media_change_notify(struct gendisk *disk)
+{
+	get_device(disk->driverfs_dev);
+	schedule_work(&disk->async_notify);
+}
+EXPORT_SYMBOL_GPL(genhd_media_change_notify);
+#endif  /*  0  */
+
+dev_t blk_lookup_devt(const char *name, int partno)
+{
+	dev_t devt = MKDEV(0, 0);
+	struct class_dev_iter iter;
+	struct device *dev;
+
+	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+	while ((dev = class_dev_iter_next(&iter))) {
+		struct gendisk *disk = dev_to_disk(dev);
+		struct hd_struct *part;
+
+		if (strcmp(dev_name(dev), name))
+			continue;
+
+		if (partno < disk->minors) {
+			/* We need to return the right devno, even
+			 * if the partition doesn't exist yet.
+			 */
+			devt = MKDEV(MAJOR(dev->devt),
+				     MINOR(dev->devt) + partno);
+			break;
+		}
+		part = disk_get_part(disk, partno);
+		if (part) {
+			devt = part_devt(part);
+			disk_put_part(part);
+			break;
+		}
+		disk_put_part(part);
+	}
+	class_dev_iter_exit(&iter);
+	return devt;
+}
+EXPORT_SYMBOL(blk_lookup_devt);
+
+struct gendisk *alloc_disk(int minors)
+{
+	return alloc_disk_node(minors, -1);
+}
+EXPORT_SYMBOL(alloc_disk);
+
+struct gendisk *alloc_disk_node(int minors, int node_id)
+{
+	struct gendisk *disk;
+
+	disk = kmalloc_node(sizeof(struct gendisk),
+				GFP_KERNEL | __GFP_ZERO, node_id);
+	if (disk) {
+		if (!init_part_stats(&disk->part0)) {
+			kfree(disk);
+			return NULL;
+		}
+		disk->node_id = node_id;
+		if (disk_expand_part_tbl(disk, 0)) {
+			free_part_stats(&disk->part0);
+			kfree(disk);
+			return NULL;
+		}
+		disk->part_tbl->part[0] = &disk->part0;
+
+		disk->minors = minors;
+#ifndef DDE_LINUX
+		rand_initialize_disk(disk);
+#endif
+		disk_to_dev(disk)->class = &block_class;
+		disk_to_dev(disk)->type = &disk_type;
+		device_initialize(disk_to_dev(disk));
+		INIT_WORK(&disk->async_notify,
+			media_change_notify_thread);
+	}
+	return disk;
+}
+EXPORT_SYMBOL(alloc_disk_node);
+
+struct kobject *get_disk(struct gendisk *disk)
+{
+	struct module *owner;
+	struct kobject *kobj;
+
+	if (!disk->fops)
+		return NULL;
+	owner = disk->fops->owner;
+	if (owner && !try_module_get(owner))
+		return NULL;
+	kobj = kobject_get(&disk_to_dev(disk)->kobj);
+	if (kobj == NULL) {
+		module_put(owner);
+		return NULL;
+	}
+	return kobj;
+
+}
+
+EXPORT_SYMBOL(get_disk);
+
+void put_disk(struct gendisk *disk)
+{
+	if (disk)
+		kobject_put(&disk_to_dev(disk)->kobj);
+}
+
+EXPORT_SYMBOL(put_disk);
+
+void set_device_ro(struct block_device *bdev, int flag)
+{
+	bdev->bd_part->policy = flag;
+}
+
+EXPORT_SYMBOL(set_device_ro);
+
+void set_disk_ro(struct gendisk *disk, int flag)
+{
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+
+	disk_part_iter_init(&piter, disk,
+			    DISK_PITER_INCL_EMPTY | DISK_PITER_INCL_PART0);
+	while ((part = disk_part_iter_next(&piter)))
+		part->policy = flag;
+	disk_part_iter_exit(&piter);
+}
+
+EXPORT_SYMBOL(set_disk_ro);
+
+int bdev_read_only(struct block_device *bdev)
+{
+	if (!bdev)
+		return 0;
+	return bdev->bd_part->policy;
+}
+
+EXPORT_SYMBOL(bdev_read_only);
+
+int invalidate_partition(struct gendisk *disk, int partno)
+{
+	int res = 0;
+	struct block_device *bdev = bdget_disk(disk, partno);
+	if (bdev) {
+		fsync_bdev(bdev);
+		res = __invalidate_device(bdev);
+		bdput(bdev);
+	}
+	return res;
+}
+
+EXPORT_SYMBOL(invalidate_partition);