Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.

1 files changed, 82 insertions, 35 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index f0640d7f800f..7da630e25ae7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -184,7 +184,7 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
 	printk(KERN_INFO "  bio %p, biotail %p, buffer %p, len %u\n",
 	       rq->bio, rq->biotail, rq->buffer, blk_rq_bytes(rq));
 
-	if (blk_pc_request(rq)) {
+	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
 		printk(KERN_INFO "  cdb: ");
 		for (bit = 0; bit < BLK_MAX_CDB; bit++)
 			printk("%02x ", rq->cmd[bit]);
@@ -608,6 +608,7 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,
 
 	q->request_fn		= rfn;
 	q->prep_rq_fn		= NULL;
+	q->unprep_rq_fn		= NULL;
 	q->unplug_fn		= generic_unplug_device;
 	q->queue_flags		= QUEUE_FLAG_DEFAULT;
 	q->queue_lock		= lock;
@@ -1135,30 +1136,46 @@ void blk_put_request(struct request *req)
 }
 EXPORT_SYMBOL(blk_put_request);
 
+/**
+ * blk_add_request_payload - add a payload to a request
+ * @rq: request to update
+ * @page: page backing the payload
+ * @len: length of the payload.
+ *
+ * This allows to later add a payload to an already submitted request by
+ * a block driver.  The driver needs to take care of freeing the payload
+ * itself.
+ *
+ * Note that this is a quite horrible hack and nothing but handling of
+ * discard requests should ever use it.
+ */
+void blk_add_request_payload(struct request *rq, struct page *page,
+		unsigned int len)
+{
+	struct bio *bio = rq->bio;
+
+	bio->bi_io_vec->bv_page = page;
+	bio->bi_io_vec->bv_offset = 0;
+	bio->bi_io_vec->bv_len = len;
+
+	bio->bi_size = len;
+	bio->bi_vcnt = 1;
+	bio->bi_phys_segments = 1;
+
+	rq->__data_len = rq->resid_len = len;
+	rq->nr_phys_segments = 1;
+	rq->buffer = bio_data(bio);
+}
+EXPORT_SYMBOL_GPL(blk_add_request_payload);
+
 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).  FAILFAST flags are identical for req and bio.
-	 */
-	if (bio_rw_flagged(bio, BIO_RW_AHEAD))
+	req->cmd_flags |= bio->bi_rw & REQ_COMMON_MASK;
+	if (bio->bi_rw & REQ_RAHEAD)
 		req->cmd_flags |= REQ_FAILFAST_MASK;
-	else
-		req->cmd_flags |= bio->bi_rw & REQ_FAILFAST_MASK;
-
-	if (bio_rw_flagged(bio, BIO_RW_DISCARD))
-		req->cmd_flags |= REQ_DISCARD;
-	if (bio_rw_flagged(bio, BIO_RW_BARRIER))
-		req->cmd_flags |= REQ_HARDBARRIER;
-	if (bio_rw_flagged(bio, BIO_RW_SYNCIO))
-		req->cmd_flags |= REQ_RW_SYNC;
-	if (bio_rw_flagged(bio, BIO_RW_META))
-		req->cmd_flags |= REQ_RW_META;
-	if (bio_rw_flagged(bio, BIO_RW_NOIDLE))
-		req->cmd_flags |= REQ_NOIDLE;
 
 	req->errors = 0;
 	req->__sector = bio->bi_sector;
@@ -1181,12 +1198,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 	int el_ret;
 	unsigned int bytes = bio->bi_size;
 	const unsigned short prio = bio_prio(bio);
-	const bool sync = bio_rw_flagged(bio, BIO_RW_SYNCIO);
-	const bool unplug = bio_rw_flagged(bio, BIO_RW_UNPLUG);
+	const bool sync = (bio->bi_rw & REQ_SYNC);
+	const bool unplug = (bio->bi_rw & REQ_UNPLUG);
 	const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
 	int rw_flags;
 
-	if (bio_rw_flagged(bio, BIO_RW_BARRIER) &&
+	if ((bio->bi_rw & REQ_HARDBARRIER) &&
 	    (q->next_ordered == QUEUE_ORDERED_NONE)) {
 		bio_endio(bio, -EOPNOTSUPP);
 		return 0;
@@ -1200,7 +1217,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 
 	spin_lock_irq(q->queue_lock);
 
-	if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER)) || elv_queue_empty(q))
+	if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
 		goto get_rq;
 
 	el_ret = elv_merge(q, &req, bio);
@@ -1275,7 +1292,7 @@ get_rq:
 	 */
 	rw_flags = bio_data_dir(bio);
 	if (sync)
-		rw_flags |= REQ_RW_SYNC;
+		rw_flags |= REQ_SYNC;
 
 	/*
 	 * Grab a free request. This is might sleep but can not fail.
@@ -1464,7 +1481,7 @@ static inline void __generic_make_request(struct bio *bio)
 			goto end_io;
 		}
 
-		if (unlikely(!bio_rw_flagged(bio, BIO_RW_DISCARD) &&
+		if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
 			     nr_sectors > queue_max_hw_sectors(q))) {
 			printk(KERN_ERR "bio too big device %s (%u > %u)\n",
 			       bdevname(bio->bi_bdev, b),
@@ -1497,8 +1514,7 @@ static inline void __generic_make_request(struct bio *bio)
 		if (bio_check_eod(bio, nr_sectors))
 			goto end_io;
 
-		if (bio_rw_flagged(bio, BIO_RW_DISCARD) &&
-		    !blk_queue_discard(q)) {
+		if ((bio->bi_rw & REQ_DISCARD) && !blk_queue_discard(q)) {
 			err = -EOPNOTSUPP;
 			goto end_io;
 		}
@@ -1583,7 +1599,7 @@ void submit_bio(int rw, struct bio *bio)
 	 * 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) && !(rw & (1 << BIO_RW_DISCARD))) {
+	if (bio_has_data(bio) && !(rw & REQ_DISCARD)) {
 		if (rw & WRITE) {
 			count_vm_events(PGPGOUT, count);
 		} else {
@@ -1628,6 +1644,9 @@ EXPORT_SYMBOL(submit_bio);
  */
 int blk_rq_check_limits(struct request_queue *q, struct request *rq)
 {
+	if (rq->cmd_flags & REQ_DISCARD)
+		return 0;
+
 	if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
 	    blk_rq_bytes(rq) > queue_max_hw_sectors(q) << 9) {
 		printk(KERN_ERR "%s: over max size limit.\n", __func__);
@@ -1796,7 +1815,7 @@ struct request *blk_peek_request(struct request_queue *q)
 			 * sees this request (possibly after
 			 * requeueing).  Notify IO scheduler.
 			 */
-			if (blk_sorted_rq(rq))
+			if (rq->cmd_flags & REQ_SORTED)
 				elv_activate_rq(q, rq);
 
 			/*
@@ -1984,10 +2003,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 	 * TODO: tj: This is too subtle.  It would be better to let
 	 * low level drivers do what they see fit.
 	 */
-	if (blk_fs_request(req))
+	if (req->cmd_type == REQ_TYPE_FS)
 		req->errors = 0;
 
-	if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) {
+	if (error && req->cmd_type == REQ_TYPE_FS &&
+	    !(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)blk_rq_pos(req));
@@ -2074,7 +2094,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 	req->buffer = bio_data(req->bio);
 
 	/* update sector only for requests with clear definition of sector */
-	if (blk_fs_request(req) || blk_discard_rq(req))
+	if (req->cmd_type == REQ_TYPE_FS || (req->cmd_flags & REQ_DISCARD))
 		req->__sector += total_bytes >> 9;
 
 	/* mixed attributes always follow the first bio */
@@ -2111,11 +2131,32 @@ static bool blk_update_bidi_request(struct request *rq, int error,
 	    blk_update_request(rq->next_rq, error, bidi_bytes))
 		return true;
 
-	add_disk_randomness(rq->rq_disk);
+	if (blk_queue_add_random(rq->q))
+		add_disk_randomness(rq->rq_disk);
 
 	return false;
 }
 
+/**
+ * blk_unprep_request - unprepare a request
+ * @req:	the request
+ *
+ * This function makes a request ready for complete resubmission (or
+ * completion).  It happens only after all error handling is complete,
+ * so represents the appropriate moment to deallocate any resources
+ * that were allocated to the request in the prep_rq_fn.  The queue
+ * lock is held when calling this.
+ */
+void blk_unprep_request(struct request *req)
+{
+	struct request_queue *q = req->q;
+
+	req->cmd_flags &= ~REQ_DONTPREP;
+	if (q->unprep_rq_fn)
+		q->unprep_rq_fn(q, req);
+}
+EXPORT_SYMBOL_GPL(blk_unprep_request);
+
 /*
  * queue lock must be held
  */
@@ -2126,11 +2167,15 @@ static void blk_finish_request(struct request *req, int error)
 
 	BUG_ON(blk_queued_rq(req));
 
-	if (unlikely(laptop_mode) && blk_fs_request(req))
+	if (unlikely(laptop_mode) && req->cmd_type == REQ_TYPE_FS)
 		laptop_io_completion(&req->q->backing_dev_info);
 
 	blk_delete_timer(req);
 
+	if (req->cmd_flags & REQ_DONTPREP)
+		blk_unprep_request(req);
+
+
 	blk_account_io_done(req);
 
 	if (req->end_io)
@@ -2363,7 +2408,7 @@ 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 */
-	rq->cmd_flags |= bio->bi_rw & REQ_RW;
+	rq->cmd_flags |= bio->bi_rw & REQ_WRITE;
 
 	if (bio_has_data(bio)) {
 		rq->nr_phys_segments = bio_phys_segments(q, bio);
@@ -2450,6 +2495,8 @@ static void __blk_rq_prep_clone(struct request *dst, struct request *src)
 {
 	dst->cpu = src->cpu;
 	dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
+	if (src->cmd_flags & REQ_DISCARD)
+		dst->cmd_flags |= REQ_DISCARD;
 	dst->cmd_type = src->cmd_type;
 	dst->__sector = blk_rq_pos(src);
 	dst->__data_len = blk_rq_bytes(src);