1 files changed, 0 insertions, 455 deletions
diff --git a/ANDROID_3.4.5/block/blk-flush.c b/ANDROID_3.4.5/block/blk-flush.c
deleted file mode 100644
index 720ad607..00000000
--- a/ANDROID_3.4.5/block/blk-flush.c
+++ /dev/null
@@ -1,455 +0,0 @@
-/*
- * Functions to sequence FLUSH and FUA writes.
- *
- * Copyright (C) 2011		Max Planck Institute for Gravitational Physics
- * Copyright (C) 2011		Tejun Heo <tj@kernel.org>
- *
- * This file is released under the GPLv2.
- *
- * REQ_{FLUSH|FUA} requests are decomposed to sequences consisted of three
- * optional steps - PREFLUSH, DATA and POSTFLUSH - according to the request
- * properties and hardware capability.
- *
- * If a request doesn't have data, only REQ_FLUSH makes sense, which
- * indicates a simple flush request.  If there is data, REQ_FLUSH indicates
- * that the device cache should be flushed before the data is executed, and
- * REQ_FUA means that the data must be on non-volatile media on request
- * completion.
- *
- * If the device doesn't have writeback cache, FLUSH and FUA don't make any
- * difference.  The requests are either completed immediately if there's no
- * data or executed as normal requests otherwise.
- *
- * If the device has writeback cache and supports FUA, REQ_FLUSH is
- * translated to PREFLUSH but REQ_FUA is passed down directly with DATA.
- *
- * If the device has writeback cache and doesn't support FUA, REQ_FLUSH is
- * translated to PREFLUSH and REQ_FUA to POSTFLUSH.
- *
- * The actual execution of flush is double buffered.  Whenever a request
- * needs to execute PRE or POSTFLUSH, it queues at
- * q->flush_queue[q->flush_pending_idx].  Once certain criteria are met, a
- * flush is issued and the pending_idx is toggled.  When the flush
- * completes, all the requests which were pending are proceeded to the next
- * step.  This allows arbitrary merging of different types of FLUSH/FUA
- * requests.
- *
- * Currently, the following conditions are used to determine when to issue
- * flush.
- *
- * C1. At any given time, only one flush shall be in progress.  This makes
- *     double buffering sufficient.
- *
- * C2. Flush is deferred if any request is executing DATA of its sequence.
- *     This avoids issuing separate POSTFLUSHes for requests which shared
- *     PREFLUSH.
- *
- * C3. The second condition is ignored if there is a request which has
- *     waited longer than FLUSH_PENDING_TIMEOUT.  This is to avoid
- *     starvation in the unlikely case where there are continuous stream of
- *     FUA (without FLUSH) requests.
- *
- * For devices which support FUA, it isn't clear whether C2 (and thus C3)
- * is beneficial.
- *
- * Note that a sequenced FLUSH/FUA request with DATA is completed twice.
- * Once while executing DATA and again after the whole sequence is
- * complete.  The first completion updates the contained bio but doesn't
- * finish it so that the bio submitter is notified only after the whole
- * sequence is complete.  This is implemented by testing REQ_FLUSH_SEQ in
- * req_bio_endio().
- *
- * The above peculiarity requires that each FLUSH/FUA request has only one
- * bio attached to it, which is guaranteed as they aren't allowed to be
- * merged in the usual way.
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-/* FLUSH/FUA sequences */
-enum {
-	REQ_FSEQ_PREFLUSH	= (1 << 0), /* pre-flushing in progress */
-	REQ_FSEQ_DATA		= (1 << 1), /* data write in progress */
-	REQ_FSEQ_POSTFLUSH	= (1 << 2), /* post-flushing in progress */
-	REQ_FSEQ_DONE		= (1 << 3),
-
-	REQ_FSEQ_ACTIONS	= REQ_FSEQ_PREFLUSH | REQ_FSEQ_DATA |
-				  REQ_FSEQ_POSTFLUSH,
-
-	/*
-	 * If flush has been pending longer than the following timeout,
-	 * it's issued even if flush_data requests are still in flight.
-	 */
-	FLUSH_PENDING_TIMEOUT	= 5 * HZ,
-};
-
-static bool blk_kick_flush(struct request_queue *q);
-
-static unsigned int blk_flush_policy(unsigned int fflags, struct request *rq)
-{
-	unsigned int policy = 0;
-
-	if (blk_rq_sectors(rq))
-		policy |= REQ_FSEQ_DATA;
-
-	if (fflags & REQ_FLUSH) {
-		if (rq->cmd_flags & REQ_FLUSH)
-			policy |= REQ_FSEQ_PREFLUSH;
-		if (!(fflags & REQ_FUA) && (rq->cmd_flags & REQ_FUA))
-			policy |= REQ_FSEQ_POSTFLUSH;
-	}
-	return policy;
-}
-
-static unsigned int blk_flush_cur_seq(struct request *rq)
-{
-	return 1 << ffz(rq->flush.seq);
-}
-
-static void blk_flush_restore_request(struct request *rq)
-{
-	/*
-	 * After flush data completion, @rq->bio is %NULL but we need to
-	 * complete the bio again.  @rq->biotail is guaranteed to equal the
-	 * original @rq->bio.  Restore it.
-	 */
-	rq->bio = rq->biotail;
-
-	/* make @rq a normal request */
-	rq->cmd_flags &= ~REQ_FLUSH_SEQ;
-	rq->end_io = rq->flush.saved_end_io;
-}
-
-/**
- * blk_flush_complete_seq - complete flush sequence
- * @rq: FLUSH/FUA request being sequenced
- * @seq: sequences to complete (mask of %REQ_FSEQ_*, can be zero)
- * @error: whether an error occurred
- *
- * @rq just completed @seq part of its flush sequence, record the
- * completion and trigger the next step.
- *
- * CONTEXT:
- * spin_lock_irq(q->queue_lock)
- *
- * RETURNS:
- * %true if requests were added to the dispatch queue, %false otherwise.
- */
-static bool blk_flush_complete_seq(struct request *rq, unsigned int seq,
-				   int error)
-{
-	struct request_queue *q = rq->q;
-	struct list_head *pending = &q->flush_queue[q->flush_pending_idx];
-	bool queued = false;
-
-	BUG_ON(rq->flush.seq & seq);
-	rq->flush.seq |= seq;
-
-	if (likely(!error))
-		seq = blk_flush_cur_seq(rq);
-	else
-		seq = REQ_FSEQ_DONE;
-
-	switch (seq) {
-	case REQ_FSEQ_PREFLUSH:
-	case REQ_FSEQ_POSTFLUSH:
-		/* queue for flush */
-		if (list_empty(pending))
-			q->flush_pending_since = jiffies;
-		list_move_tail(&rq->flush.list, pending);
-		break;
-
-	case REQ_FSEQ_DATA:
-		list_move_tail(&rq->flush.list, &q->flush_data_in_flight);
-		list_add(&rq->queuelist, &q->queue_head);
-		queued = true;
-		break;
-
-	case REQ_FSEQ_DONE:
-		/*
-		 * @rq was previously adjusted by blk_flush_issue() for
-		 * flush sequencing and may already have gone through the
-		 * flush data request completion path.  Restore @rq for
-		 * normal completion and end it.
-		 */
-		BUG_ON(!list_empty(&rq->queuelist));
-		list_del_init(&rq->flush.list);
-		blk_flush_restore_request(rq);
-		__blk_end_request_all(rq, error);
-		break;
-
-	default:
-		BUG();
-	}
-
-	return blk_kick_flush(q) | queued;
-}
-
-static void flush_end_io(struct request *flush_rq, int error)
-{
-	struct request_queue *q = flush_rq->q;
-	struct list_head *running = &q->flush_queue[q->flush_running_idx];
-	bool queued = false;
-	struct request *rq, *n;
-
-	BUG_ON(q->flush_pending_idx == q->flush_running_idx);
-
-	/* account completion of the flush request */
-	q->flush_running_idx ^= 1;
-	elv_completed_request(q, flush_rq);
-
-	/* and push the waiting requests to the next stage */
-	list_for_each_entry_safe(rq, n, running, flush.list) {
-		unsigned int seq = blk_flush_cur_seq(rq);
-
-		BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH);
-		queued |= blk_flush_complete_seq(rq, seq, error);
-	}
-
-	/*
-	 * Kick the queue to avoid stall for two cases:
-	 * 1. Moving a request silently to empty queue_head may stall the
-	 * queue.
-	 * 2. When flush request is running in non-queueable queue, the
-	 * queue is hold. Restart the queue after flush request is finished
-	 * to avoid stall.
-	 * This function is called from request completion path and calling
-	 * directly into request_fn may confuse the driver.  Always use
-	 * kblockd.
-	 */
-	if (queued || q->flush_queue_delayed)
-		blk_run_queue_async(q);
-	q->flush_queue_delayed = 0;
-}
-
-/**
- * blk_kick_flush - consider issuing flush request
- * @q: request_queue being kicked
- *
- * Flush related states of @q have changed, consider issuing flush request.
- * Please read the comment at the top of this file for more info.
- *
- * CONTEXT:
- * spin_lock_irq(q->queue_lock)
- *
- * RETURNS:
- * %true if flush was issued, %false otherwise.
- */
-static bool blk_kick_flush(struct request_queue *q)
-{
-	struct list_head *pending = &q->flush_queue[q->flush_pending_idx];
-	struct request *first_rq =
-		list_first_entry(pending, struct request, flush.list);
-
-	/* C1 described at the top of this file */
-	if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending))
-		return false;
-
-	/* C2 and C3 */
-	if (!list_empty(&q->flush_data_in_flight) &&
-	    time_before(jiffies,
-			q->flush_pending_since + FLUSH_PENDING_TIMEOUT))
-		return false;
-
-	/*
-	 * Issue flush and toggle pending_idx.  This makes pending_idx
-	 * different from running_idx, which means flush is in flight.
-	 */
-	blk_rq_init(q, &q->flush_rq);
-	q->flush_rq.cmd_type = REQ_TYPE_FS;
-	q->flush_rq.cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ;
-	q->flush_rq.rq_disk = first_rq->rq_disk;
-	q->flush_rq.end_io = flush_end_io;
-
-	q->flush_pending_idx ^= 1;
-	list_add_tail(&q->flush_rq.queuelist, &q->queue_head);
-	return true;
-}
-
-static void flush_data_end_io(struct request *rq, int error)
-{
-	struct request_queue *q = rq->q;
-
-	/*
-	 * After populating an empty queue, kick it to avoid stall.  Read
-	 * the comment in flush_end_io().
-	 */
-	if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error))
-		blk_run_queue_async(q);
-}
-
-/**
- * blk_insert_flush - insert a new FLUSH/FUA request
- * @rq: request to insert
- *
- * To be called from __elv_add_request() for %ELEVATOR_INSERT_FLUSH insertions.
- * @rq is being submitted.  Analyze what needs to be done and put it on the
- * right queue.
- *
- * CONTEXT:
- * spin_lock_irq(q->queue_lock)
- */
-void blk_insert_flush(struct request *rq)
-{
-	struct request_queue *q = rq->q;
-	unsigned int fflags = q->flush_flags;	/* may change, cache */
-	unsigned int policy = blk_flush_policy(fflags, rq);
-
-	/*
-	 * @policy now records what operations need to be done.  Adjust
-	 * REQ_FLUSH and FUA for the driver.
-	 */
-	rq->cmd_flags &= ~REQ_FLUSH;
-	if (!(fflags & REQ_FUA))
-		rq->cmd_flags &= ~REQ_FUA;
-
-	/*
-	 * An empty flush handed down from a stacking driver may
-	 * translate into nothing if the underlying device does not
-	 * advertise a write-back cache.  In this case, simply
-	 * complete the request.
-	 */
-	if (!policy) {
-		__blk_end_bidi_request(rq, 0, 0, 0);
-		return;
-	}
-
-	BUG_ON(rq->bio != rq->biotail); /*assumes zero or single bio rq */
-
-	/*
-	 * If there's data but flush is not necessary, the request can be
-	 * processed directly without going through flush machinery.  Queue
-	 * for normal execution.
-	 */
-	if ((policy & REQ_FSEQ_DATA) &&
-	    !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
-		list_add_tail(&rq->queuelist, &q->queue_head);
-		return;
-	}
-
-	/*
-	 * @rq should go through flush machinery.  Mark it part of flush
-	 * sequence and submit for further processing.
-	 */
-	memset(&rq->flush, 0, sizeof(rq->flush));
-	INIT_LIST_HEAD(&rq->flush.list);
-	rq->cmd_flags |= REQ_FLUSH_SEQ;
-	rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
-	rq->end_io = flush_data_end_io;
-
-	blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0);
-}
-
-/**
- * blk_abort_flushes - @q is being aborted, abort flush requests
- * @q: request_queue being aborted
- *
- * To be called from elv_abort_queue().  @q is being aborted.  Prepare all
- * FLUSH/FUA requests for abortion.
- *
- * CONTEXT:
- * spin_lock_irq(q->queue_lock)
- */
-void blk_abort_flushes(struct request_queue *q)
-{
-	struct request *rq, *n;
-	int i;
-
-	/*
-	 * Requests in flight for data are already owned by the dispatch
-	 * queue or the device driver.  Just restore for normal completion.
-	 */
-	list_for_each_entry_safe(rq, n, &q->flush_data_in_flight, flush.list) {
-		list_del_init(&rq->flush.list);
-		blk_flush_restore_request(rq);
-	}
-
-	/*
-	 * We need to give away requests on flush queues.  Restore for
-	 * normal completion and put them on the dispatch queue.
-	 */
-	for (i = 0; i < ARRAY_SIZE(q->flush_queue); i++) {
-		list_for_each_entry_safe(rq, n, &q->flush_queue[i],
-					 flush.list) {
-			list_del_init(&rq->flush.list);
-			blk_flush_restore_request(rq);
-			list_add_tail(&rq->queuelist, &q->queue_head);
-		}
-	}
-}
-
-static void bio_end_flush(struct bio *bio, int err)
-{
-	if (err)
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
-	if (bio->bi_private)
-		complete(bio->bi_private);
-	bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev:	blockdev to issue flush for
- * @gfp_mask:	memory allocation flags (for bio_alloc)
- * @error_sector:	error sector
- *
- * Description:
- *    Issue a flush for the block device in question. Caller can supply
- *    room for storing the error offset in case of a flush error, if they
- *    wish to. If WAIT flag is not passed then caller may check only what
- *    request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
-		sector_t *error_sector)
-{
-	DECLARE_COMPLETION_ONSTACK(wait);
-	struct request_queue *q;
-	struct bio *bio;
-	int ret = 0;
-
-	if (bdev->bd_disk == NULL)
-		return -ENXIO;
-
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
-	/*
-	 * some block devices may not have their queue correctly set up here
-	 * (e.g. loop device without a backing file) and so issuing a flush
-	 * here will panic. Ensure there is a request function before issuing
-	 * the flush.
-	 */
-	if (!q->make_request_fn)
-		return -ENXIO;
-
-	bio = bio_alloc(gfp_mask, 0);
-	bio->bi_end_io = bio_end_flush;
-	bio->bi_bdev = bdev;
-	bio->bi_private = &wait;
-
-	bio_get(bio);
-	submit_bio(WRITE_FLUSH, bio);
-	wait_for_completion(&wait);
-
-	/*
-	 * The driver must store the error location in ->bi_sector, if
-	 * it supports it. For non-stacked drivers, this should be
-	 * copied from blk_rq_pos(rq).
-	 */
-	if (error_sector)
-               *error_sector = bio->bi_sector;
-
-	if (!bio_flagged(bio, BIO_UPTODATE))
-		ret = -EIO;
-
-	bio_put(bio);
-	return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);