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

Pull block fixes from Jens Axboe:
 "Here's the second round of block updates for this merge window.

  It's a mix of fixes for changes that went in previously in this round,
  and fixes in general.  This pull request contains:

   - Fixes for loop from Christoph

   - A bdi vs gendisk lifetime fix from Dan, worth two cookies.

   - A blk-mq timeout fix, when on frozen queues.  From Gabriel.

   - Writeback fix from Jan, ensuring that __writeback_single_inode()
     does the right thing.

   - Fix for bio->bi_rw usage in f2fs from me.

   - Error path deadlock fix in blk-mq sysfs registration from me.

   - Floppy O_ACCMODE fix from Jiri.

   - Fix to the new bio op methods from Mike.

     One more followup will be coming here, ensuring that we don't
     propagate the block types outside of block.  That, and a rename of
     bio->bi_rw is coming right after -rc1 is cut.

   - Various little fixes"

* 'for-linus' of git://git.kernel.dk/linux-block:
  mm/block: convert rw_page users to bio op use
  loop: make do_req_filebacked more robust
  loop: don't try to use AIO for discards
  blk-mq: fix deadlock in blk_mq_register_disk() error path
  Include: blkdev: Removed duplicate 'struct request;' declaration.
  Fixup direct bi_rw modifiers
  block: fix bdi vs gendisk lifetime mismatch
  blk-mq: Allow timeouts to run while queue is freezing
  nbd: fix race in ioctl
  block: fix use-after-free in seq file
  f2fs: drop bio->bi_rw manual assignment
  block: add missing group association in bio-cloning functions
  blkcg: kill unused field nr_undestroyed_grps
  writeback: Write dirty times for WB_SYNC_ALL writeback
  floppy: fix open(O_ACCMODE) for ioctl-only open

block/bio.c

@@ -583,6 +583,8 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
 	bio->bi_rw = bio_src->bi_rw;
 	bio->bi_iter = bio_src->bi_iter;
 	bio->bi_io_vec = bio_src->bi_io_vec;
+
+	bio_clone_blkcg_association(bio, bio_src);
 }
 EXPORT_SYMBOL(__bio_clone_fast);
 
@@ -687,6 +689,8 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
 		}
 	}
 
+	bio_clone_blkcg_association(bio, bio_src);
+
 	return bio;
 }
 EXPORT_SYMBOL(bio_clone_bioset);
@@ -2004,6 +2008,17 @@ void bio_disassociate_task(struct bio *bio)
 	}
 }
 
+/**
+ * bio_clone_blkcg_association - clone blkcg association from src to dst bio
+ * @dst: destination bio
+ * @src: source bio
+ */
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
+{
+	if (src->bi_css)
+		WARN_ON(bio_associate_blkcg(dst, src->bi_css));
+}
+
 #endif /* CONFIG_BLK_CGROUP */
 
 static void __init biovec_init_slabs(void)

block/blk-mq-sysfs.c

@@ -380,15 +380,13 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
 	return ret;
 }
 
-void blk_mq_unregister_disk(struct gendisk *disk)
+static void __blk_mq_unregister_disk(struct gendisk *disk)
 {
 	struct request_queue *q = disk->queue;
 	struct blk_mq_hw_ctx *hctx;
 	struct blk_mq_ctx *ctx;
 	int i, j;
 
-	blk_mq_disable_hotplug();
-
 	queue_for_each_hw_ctx(q, hctx, i) {
 		blk_mq_unregister_hctx(hctx);
 
@@ -405,6 +403,12 @@ void blk_mq_unregister_disk(struct gendisk *disk)
 	kobject_put(&disk_to_dev(disk)->kobj);
 
 	q->mq_sysfs_init_done = false;
+}
+
+void blk_mq_unregister_disk(struct gendisk *disk)
+{
+	blk_mq_disable_hotplug();
+	__blk_mq_unregister_disk(disk);
 	blk_mq_enable_hotplug();
 }
 
@@ -450,7 +454,7 @@ int blk_mq_register_disk(struct gendisk *disk)
 	}
 
 	if (ret)
-		blk_mq_unregister_disk(disk);
+		__blk_mq_unregister_disk(disk);
 	else
 		q->mq_sysfs_init_done = true;
 out:

block/blk-mq.c

@@ -672,7 +672,20 @@ static void blk_mq_timeout_work(struct work_struct *work)
 	};
 	int i;
 
-	if (blk_queue_enter(q, true))
+	/* A deadlock might occur if a request is stuck requiring a
+	 * timeout at the same time a queue freeze is waiting
+	 * completion, since the timeout code would not be able to
+	 * acquire the queue reference here.
+	 *
+	 * That's why we don't use blk_queue_enter here; instead, we use
+	 * percpu_ref_tryget directly, because we need to be able to
+	 * obtain a reference even in the short window between the queue
+	 * starting to freeze, by dropping the first reference in
+	 * blk_mq_freeze_queue_start, and the moment the last request is
+	 * consumed, marked by the instant q_usage_counter reaches
+	 * zero.
+	 */
+	if (!percpu_ref_tryget(&q->q_usage_counter))
 		return;
 
 	blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);

block/blk-throttle.c

@@ -145,11 +145,6 @@ struct throtl_data
 	/* Total Number of queued bios on READ and WRITE lists */
 	unsigned int nr_queued[2];
 
-	/*
-	 * number of total undestroyed groups
-	 */
-	unsigned int nr_undestroyed_grps;
-
 	/* Work for dispatching throttled bios */
 	struct work_struct dispatch_work;
 };

block/genhd.c

@@ -614,7 +614,7 @@ void device_add_disk(struct device *parent, struct gendisk *disk)
 
 	/* Register BDI before referencing it from bdev */
 	bdi = &disk->queue->backing_dev_info;
-	bdi_register_dev(bdi, disk_devt(disk));
+	bdi_register_owner(bdi, disk_to_dev(disk));
 
 	blk_register_region(disk_devt(disk), disk->minors, NULL,
 			    exact_match, exact_lock, disk);
@@ -856,6 +856,7 @@ static void disk_seqf_stop(struct seq_file *seqf, void *v)
 	if (iter) {
 		class_dev_iter_exit(iter);
 		kfree(iter);
+		seqf->private = NULL;
 	}
 }
 

drivers/block/brd.c

@@ -300,20 +300,20 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
  * Process a single bvec of a bio.
  */
 static int brd_do_bvec(struct brd_device *brd, struct page *page,
-			unsigned int len, unsigned int off, int rw,
+			unsigned int len, unsigned int off, int op,
 			sector_t sector)
 {
 	void *mem;
 	int err = 0;
 
-	if (rw != READ) {
+	if (op_is_write(op)) {
 		err = copy_to_brd_setup(brd, sector, len);
 		if (err)
 			goto out;
 	}
 
 	mem = kmap_atomic(page);
-	if (rw == READ) {
+	if (!op_is_write(op)) {
 		copy_from_brd(mem + off, brd, sector, len);
 		flush_dcache_page(page);
 	} else {
@@ -330,7 +330,6 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct block_device *bdev = bio->bi_bdev;
 	struct brd_device *brd = bdev->bd_disk->private_data;
-	int rw;
 	struct bio_vec bvec;
 	sector_t sector;
 	struct bvec_iter iter;
@@ -347,14 +346,12 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
 		goto out;
 	}
 
-	rw = bio_data_dir(bio);
-
 	bio_for_each_segment(bvec, bio, iter) {
 		unsigned int len = bvec.bv_len;
 		int err;
 
 		err = brd_do_bvec(brd, bvec.bv_page, len,
-					bvec.bv_offset, rw, sector);
+					bvec.bv_offset, bio_op(bio), sector);
 		if (err)
 			goto io_error;
 		sector += len >> SECTOR_SHIFT;
@@ -369,11 +366,11 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
 }
 
 static int brd_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, int rw)
+		       struct page *page, int op)
 {
 	struct brd_device *brd = bdev->bd_disk->private_data;
-	int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, rw, sector);
-	page_endio(page, rw & WRITE, err);
+	int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, op, sector);
+	page_endio(page, op, err);
 	return err;
 }
 

drivers/block/floppy.c

@@ -3663,11 +3663,6 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 
 	opened_bdev[drive] = bdev;
 
-	if (!(mode & (FMODE_READ|FMODE_WRITE))) {
-		res = -EINVAL;
-		goto out;
-	}
-
 	res = -ENXIO;
 
 	if (!floppy_track_buffer) {
@@ -3711,6 +3706,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 	if (UFDCS->rawcmd == 1)
 		UFDCS->rawcmd = 2;
 
+	if (mode & (FMODE_READ|FMODE_WRITE)) {
 		UDRS->last_checked = 0;
 		clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
 		check_disk_change(bdev);
@@ -3718,6 +3714,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 			goto out;
 		if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
 			goto out;
+	}
 
 	res = -EROFS;
 

drivers/block/loop.c

@@ -510,14 +510,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 	return 0;
 }
 
-
-static inline int lo_rw_simple(struct loop_device *lo,
-		struct request *rq, loff_t pos, bool rw)
+static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 {
 	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
-
-	if (cmd->use_aio)
-		return lo_rw_aio(lo, cmd, pos, rw);
+	loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
 
 	/*
 	 * lo_write_simple and lo_read_simple should have been covered
@@ -528,37 +524,30 @@ static inline int lo_rw_simple(struct loop_device *lo,
 	 * of the req at one time. And direct read IO doesn't need to
 	 * run flush_dcache_page().
 	 */
-	if (rw == WRITE)
-		return lo_write_simple(lo, rq, pos);
-	else
-		return lo_read_simple(lo, rq, pos);
-}
-
-static int do_req_filebacked(struct loop_device *lo, struct request *rq)
-{
-	loff_t pos;
-	int ret;
-
-	pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
-
-	if (op_is_write(req_op(rq))) {
-		if (req_op(rq) == REQ_OP_FLUSH)
-			ret = lo_req_flush(lo, rq);
-		else if (req_op(rq) == REQ_OP_DISCARD)
-			ret = lo_discard(lo, rq, pos);
-		else if (lo->transfer)
-			ret = lo_write_transfer(lo, rq, pos);
+	switch (req_op(rq)) {
+	case REQ_OP_FLUSH:
+		return lo_req_flush(lo, rq);
+	case REQ_OP_DISCARD:
+		return lo_discard(lo, rq, pos);
+	case REQ_OP_WRITE:
+		if (lo->transfer)
+			return lo_write_transfer(lo, rq, pos);
+		else if (cmd->use_aio)
+			return lo_rw_aio(lo, cmd, pos, WRITE);
 		else
-			ret = lo_rw_simple(lo, rq, pos, WRITE);
-
-	} else {
+			return lo_write_simple(lo, rq, pos);
+	case REQ_OP_READ:
 		if (lo->transfer)
-			ret = lo_read_transfer(lo, rq, pos);
+			return lo_read_transfer(lo, rq, pos);
+		else if (cmd->use_aio)
+			return lo_rw_aio(lo, cmd, pos, READ);
 		else
-			ret = lo_rw_simple(lo, rq, pos, READ);
+			return lo_read_simple(lo, rq, pos);
+	default:
+		WARN_ON_ONCE(1);
+		return -EIO;
+		break;
 	}
-
-	return ret;
 }
 
 struct switch_request {
@@ -1659,11 +1648,15 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (lo->lo_state != Lo_bound)
 		return -EIO;
 
-	if (lo->use_dio && (req_op(cmd->rq) != REQ_OP_FLUSH ||
-	    req_op(cmd->rq) == REQ_OP_DISCARD))
-		cmd->use_aio = true;
-	else
+	switch (req_op(cmd->rq)) {
+	case REQ_OP_FLUSH:
+	case REQ_OP_DISCARD:
 		cmd->use_aio = false;
+		break;
+	default:
+		cmd->use_aio = lo->use_dio;
+		break;
+	}
 
 	queue_kthread_work(&lo->worker, &cmd->work);
 

drivers/block/nbd.c

@@ -451,14 +451,9 @@ static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)
 
 	sk_set_memalloc(nbd->sock->sk);
 
-	nbd->task_recv = current;
-
 	ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
 	if (ret) {
 		dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
-
-		nbd->task_recv = NULL;
-
 		return ret;
 	}
 
@@ -477,9 +472,6 @@ static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)
 	nbd_size_clear(nbd, bdev);
 
 	device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
-
-	nbd->task_recv = NULL;
-
 	return ret;
 }
 
@@ -788,6 +780,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 		if (!nbd->sock)
 			return -EINVAL;
 
+		/* We have to claim the device under the lock */
+		nbd->task_recv = current;
 		mutex_unlock(&nbd->tx_lock);
 
 		nbd_parse_flags(nbd, bdev);
@@ -796,6 +790,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 				     nbd_name(nbd));
 		if (IS_ERR(thread)) {
 			mutex_lock(&nbd->tx_lock);
+			nbd->task_recv = NULL;
 			return PTR_ERR(thread);
 		}
 
@@ -805,6 +800,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 		kthread_stop(thread);
 
 		mutex_lock(&nbd->tx_lock);
+		nbd->task_recv = NULL;
 
 		sock_shutdown(nbd);
 		nbd_clear_que(nbd);

drivers/block/zram/zram_drv.c

@@ -843,15 +843,15 @@ static void zram_bio_discard(struct zram *zram, u32 index,
 }
 
 static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
-			int offset, int rw)
+			int offset, int op)
 {
 	unsigned long start_time = jiffies;
 	int ret;
 
-	generic_start_io_acct(rw, bvec->bv_len >> SECTOR_SHIFT,
+	generic_start_io_acct(op, bvec->bv_len >> SECTOR_SHIFT,
 			&zram->disk->part0);
 
-	if (rw == READ) {
+	if (!op_is_write(op)) {
 		atomic64_inc(&zram->stats.num_reads);
 		ret = zram_bvec_read(zram, bvec, index, offset);
 	} else {
@@ -859,10 +859,10 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
 		ret = zram_bvec_write(zram, bvec, index, offset);
 	}
 
-	generic_end_io_acct(rw, &zram->disk->part0, start_time);
+	generic_end_io_acct(op, &zram->disk->part0, start_time);
 
 	if (unlikely(ret)) {
-		if (rw == READ)
+		if (!op_is_write(op))
 			atomic64_inc(&zram->stats.failed_reads);
 		else
 			atomic64_inc(&zram->stats.failed_writes);
@@ -873,7 +873,7 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
 
 static void __zram_make_request(struct zram *zram, struct bio *bio)
 {
-	int offset, rw;
+	int offset;
 	u32 index;
 	struct bio_vec bvec;
 	struct bvec_iter iter;
@@ -888,7 +888,6 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
 		return;
 	}
 
-	rw = bio_data_dir(bio);
 	bio_for_each_segment(bvec, bio, iter) {
 		int max_transfer_size = PAGE_SIZE - offset;
 
@@ -903,15 +902,18 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
 			bv.bv_len = max_transfer_size;
 			bv.bv_offset = bvec.bv_offset;
 
-			if (zram_bvec_rw(zram, &bv, index, offset, rw) < 0)
+			if (zram_bvec_rw(zram, &bv, index, offset,
+					 bio_op(bio)) < 0)
 				goto out;
 
 			bv.bv_len = bvec.bv_len - max_transfer_size;
 			bv.bv_offset += max_transfer_size;
-			if (zram_bvec_rw(zram, &bv, index + 1, 0, rw) < 0)
+			if (zram_bvec_rw(zram, &bv, index + 1, 0,
+					 bio_op(bio)) < 0)
 				goto out;
 		} else
-			if (zram_bvec_rw(zram, &bvec, index, offset, rw) < 0)
+			if (zram_bvec_rw(zram, &bvec, index, offset,
+					 bio_op(bio)) < 0)
 				goto out;
 
 		update_position(&index, &offset, &bvec);
@@ -968,7 +970,7 @@ static void zram_slot_free_notify(struct block_device *bdev,
 }
 
 static int zram_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, int rw)
+		       struct page *page, int op)
 {
 	int offset, err = -EIO;
 	u32 index;
@@ -992,7 +994,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
 	bv.bv_len = PAGE_SIZE;
 	bv.bv_offset = 0;
 
-	err = zram_bvec_rw(zram, &bv, index, offset, rw);
+	err = zram_bvec_rw(zram, &bv, index, offset, op);
 put_zram:
 	zram_meta_put(zram);
 out:
@@ -1005,7 +1007,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
 	 * (e.g., SetPageError, set_page_dirty and extra works).
 	 */
 	if (err == 0)
-		page_endio(page, rw, 0);
+		page_endio(page, op, 0);
 	return err;
 }
 

drivers/nvdimm/btt.c

@@ -1133,11 +1133,11 @@ static int btt_write_pg(struct btt *btt, struct bio_integrity_payload *bip,
 
 static int btt_do_bvec(struct btt *btt, struct bio_integrity_payload *bip,
 			struct page *page, unsigned int len, unsigned int off,
-			int rw, sector_t sector)
+			int op, sector_t sector)
 {
 	int ret;
 
-	if (rw == READ) {
+	if (!op_is_write(op)) {
 		ret = btt_read_pg(btt, bip, page, off, sector, len);
 		flush_dcache_page(page);
 	} else {
@@ -1155,7 +1155,7 @@ static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
 	struct bvec_iter iter;
 	unsigned long start;
 	struct bio_vec bvec;
-	int err = 0, rw;
+	int err = 0;
 	bool do_acct;
 
 	/*
@@ -1170,7 +1170,6 @@ static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
 	}
 
 	do_acct = nd_iostat_start(bio, &start);
-	rw = bio_data_dir(bio);
 	bio_for_each_segment(bvec, bio, iter) {
 		unsigned int len = bvec.bv_len;
 
@@ -1181,11 +1180,12 @@ static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
 		BUG_ON(len % btt->sector_size);
 
 		err = btt_do_bvec(btt, bip, bvec.bv_page, len, bvec.bv_offset,
-				rw, iter.bi_sector);
+				  bio_op(bio), iter.bi_sector);
 		if (err) {
 			dev_info(&btt->nd_btt->dev,
 					"io error in %s sector %lld, len %d,\n",
-					(rw == READ) ? "READ" : "WRITE",
+					(op_is_write(bio_op(bio))) ? "WRITE" :
+					"READ",
 					(unsigned long long) iter.bi_sector, len);
 			bio->bi_error = err;
 			break;
@@ -1200,12 +1200,12 @@ static blk_qc_t btt_make_request(struct request_queue *q, struct bio *bio)
 }
 
 static int btt_rw_page(struct block_device *bdev, sector_t sector,
-		struct page *page, int rw)
+		struct page *page, int op)
 {
 	struct btt *btt = bdev->bd_disk->private_data;
 
-	btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, rw, sector);
-	page_endio(page, rw & WRITE, 0);
+	btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, op, sector);
+	page_endio(page, op, 0);
 	return 0;
 }
 

drivers/nvdimm/pmem.c

@@ -67,7 +67,7 @@ static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
 }
 
 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
-			unsigned int len, unsigned int off, int rw,
+			unsigned int len, unsigned int off, int op,
 			sector_t sector)
 {
 	int rc = 0;
@@ -79,7 +79,7 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
 	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
 		bad_pmem = true;
 
-	if (rw == READ) {
+	if (!op_is_write(op)) {
 		if (unlikely(bad_pmem))
 			rc = -EIO;
 		else {
@@ -134,7 +134,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 	do_acct = nd_iostat_start(bio, &start);
 	bio_for_each_segment(bvec, bio, iter) {
 		rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
-				bvec.bv_offset, bio_data_dir(bio),
+				bvec.bv_offset, bio_op(bio),
 				iter.bi_sector);
 		if (rc) {
 			bio->bi_error = rc;
@@ -152,12 +152,12 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 }
 
 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, int rw)
+		       struct page *page, int op)
 {
 	struct pmem_device *pmem = bdev->bd_queue->queuedata;
 	int rc;
 
-	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
+	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, op, sector);
 
 	/*
 	 * The ->rw_page interface is subtle and tricky.  The core
@@ -166,7 +166,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 	 * caused by double completion.
 	 */
 	if (rc == 0)
-		page_endio(page, rw & WRITE, 0);
+		page_endio(page, op, 0);
 
 	return rc;
 }

fs/block_dev.c

@@ -416,7 +416,8 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
 	result = blk_queue_enter(bdev->bd_queue, false);
 	if (result)
 		return result;
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ);
+	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
+			      REQ_OP_READ);
 	blk_queue_exit(bdev->bd_queue);
 	return result;
 }
@@ -445,7 +446,6 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 			struct page *page, struct writeback_control *wbc)
 {
 	int result;
-	int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE;
 	const struct block_device_operations *ops = bdev->bd_disk->fops;
 
 	if (!ops->rw_page || bdev_get_integrity(bdev))
@@ -455,7 +455,8 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 		return result;
 
 	set_page_writeback(page);
-	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw);
+	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
+			      REQ_OP_WRITE);
 	if (result)
 		end_page_writeback(page);
 	else

fs/btrfs/extent_io.c

@@ -2049,7 +2049,7 @@ int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
 		return -EIO;
 	}
 	bio->bi_bdev = dev->bdev;
-	bio->bi_rw = WRITE_SYNC;
+	bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_SYNC);
 	bio_add_page(bio, page, length, pg_offset);
 
 	if (btrfsic_submit_bio_wait(bio)) {
@@ -2697,12 +2697,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
 		btrfs_bio->csum = NULL;
 		btrfs_bio->csum_allocated = NULL;
 		btrfs_bio->end_io = NULL;
-
-#ifdef CONFIG_BLK_CGROUP
-		/* FIXME, put this into bio_clone_bioset */
-		if (bio->bi_css)
-			bio_associate_blkcg(new, bio->bi_css);
-#endif
 	}
 	return new;
 }

fs/f2fs/data.c

@@ -245,7 +245,6 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 		bio_put(bio);
 		return -EFAULT;
 	}
-	bio->bi_rw = fio->op_flags;
 	bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
 	__submit_bio(fio->sbi, bio, fio->type);

fs/fs-writeback.c

@@ -1327,6 +1327,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
 	dirty = inode->i_state & I_DIRTY;
 	if (inode->i_state & I_DIRTY_TIME) {
 		if ((dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) ||
+		    wbc->sync_mode == WB_SYNC_ALL ||
 		    unlikely(inode->i_state & I_DIRTY_TIME_EXPIRED) ||
 		    unlikely(time_after(jiffies,
 					(inode->dirtied_time_when +

fs/mpage.c

@@ -50,7 +50,7 @@ static void mpage_end_io(struct bio *bio)
 
 	bio_for_each_segment_all(bv, bio, i) {
 		struct page *page = bv->bv_page;
-		page_endio(page, bio_data_dir(bio), bio->bi_error);
+		page_endio(page, bio_op(bio), bio->bi_error);
 	}
 
 	bio_put(bio);

include/linux/backing-dev-defs.h

@@ -163,6 +163,7 @@ struct backing_dev_info {
 	wait_queue_head_t wb_waitq;
 
 	struct device *dev;
+	struct device *owner;
 
 	struct timer_list laptop_mode_wb_timer;
 

include/linux/backing-dev.h

@@ -24,6 +24,7 @@ __printf(3, 4)
 int bdi_register(struct backing_dev_info *bdi, struct device *parent,
 		const char *fmt, ...);
 int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
+int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner);
 void bdi_unregister(struct backing_dev_info *bdi);
 
 int __must_check bdi_setup_and_register(struct backing_dev_info *, char *);

include/linux/bio.h

@@ -470,11 +470,14 @@ extern unsigned int bvec_nr_vecs(unsigned short idx);
 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
 int bio_associate_current(struct bio *bio);
 void bio_disassociate_task(struct bio *bio);
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
 #else	/* CONFIG_BLK_CGROUP */
 static inline int bio_associate_blkcg(struct bio *bio,
 			struct cgroup_subsys_state *blkcg_css) { return 0; }
 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
 static inline void bio_disassociate_task(struct bio *bio) { }
+static inline void bio_clone_blkcg_association(struct bio *dst,
+			struct bio *src) { }
 #endif	/* CONFIG_BLK_CGROUP */
 
 #ifdef CONFIG_HIGHMEM

include/linux/blk_types.h

@@ -18,6 +18,17 @@ struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
 typedef void (bio_destructor_t) (struct bio *);
 
+enum req_op {
+	REQ_OP_READ,
+	REQ_OP_WRITE,
+	REQ_OP_DISCARD,		/* request to discard sectors */
+	REQ_OP_SECURE_ERASE,	/* request to securely erase sectors */
+	REQ_OP_WRITE_SAME,	/* write same block many times */
+	REQ_OP_FLUSH,		/* request for cache flush */
+};
+
+#define REQ_OP_BITS 3
+
 #ifdef CONFIG_BLOCK
 /*
  * main unit of I/O for the block layer and lower layers (ie drivers and
@@ -228,17 +239,6 @@ enum rq_flag_bits {
 #define REQ_HASHED		(1ULL << __REQ_HASHED)
 #define REQ_MQ_INFLIGHT		(1ULL << __REQ_MQ_INFLIGHT)
 
-enum req_op {
-	REQ_OP_READ,
-	REQ_OP_WRITE,
-	REQ_OP_DISCARD,		/* request to discard sectors */
-	REQ_OP_SECURE_ERASE,	/* request to securely erase sectors */
-	REQ_OP_WRITE_SAME,	/* write same block many times */
-	REQ_OP_FLUSH,		/* request for cache flush */
-};
-
-#define REQ_OP_BITS 3
-
 typedef unsigned int blk_qc_t;
 #define BLK_QC_T_NONE	-1U
 #define BLK_QC_T_SHIFT	16

include/linux/blkdev.h

@@ -47,7 +47,6 @@ struct pr_ops;
  */
 #define BLKCG_MAX_POLS		2
 
-struct request;
 typedef void (rq_end_io_fn)(struct request *, int);
 
 #define BLK_RL_SYNCFULL		(1U << 0)
@@ -1673,7 +1672,7 @@ struct blk_dax_ctl {
 struct block_device_operations {
 	int (*open) (struct block_device *, fmode_t);
 	void (*release) (struct gendisk *, fmode_t);
-	int (*rw_page)(struct block_device *, sector_t, struct page *, int rw);
+	int (*rw_page)(struct block_device *, sector_t, struct page *, int op);
 	int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
 	long (*direct_access)(struct block_device *, sector_t, void **, pfn_t *,

include/linux/fs.h

@@ -2480,12 +2480,13 @@ extern void init_special_inode(struct inode *, umode_t, dev_t);
 extern void make_bad_inode(struct inode *);
 extern bool is_bad_inode(struct inode *);
 
-#ifdef CONFIG_BLOCK
 static inline bool op_is_write(unsigned int op)
 {
 	return op == REQ_OP_READ ? false : true;
 }
 
+#ifdef CONFIG_BLOCK
+
 /*
  * return data direction, READ or WRITE
  */

include/linux/pagemap.h

@@ -510,7 +510,7 @@ static inline void wait_on_page_writeback(struct page *page)
 extern void end_page_writeback(struct page *page);
 void wait_for_stable_page(struct page *page);
 
-void page_endio(struct page *page, int rw, int err);
+void page_endio(struct page *page, int op, int err);
 
 /*
  * Add an arbitrary waiter to a page's wait queue

mm/backing-dev.c

@@ -825,6 +825,20 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
 }
 EXPORT_SYMBOL(bdi_register_dev);
 
+int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner)
+{
+	int rc;
+
+	rc = bdi_register(bdi, NULL, "%u:%u", MAJOR(owner->devt),
+			MINOR(owner->devt));
+	if (rc)
+		return rc;
+	bdi->owner = owner;
+	get_device(owner);
+	return 0;
+}
+EXPORT_SYMBOL(bdi_register_owner);
+
 /*
  * Remove bdi from bdi_list, and ensure that it is no longer visible
  */
@@ -849,6 +863,11 @@ void bdi_unregister(struct backing_dev_info *bdi)
 		device_unregister(bdi->dev);
 		bdi->dev = NULL;
 	}
+
+	if (bdi->owner) {
+		put_device(bdi->owner);
+		bdi->owner = NULL;
+	}
 }
 
 void bdi_exit(struct backing_dev_info *bdi)

mm/filemap.c

@@ -887,9 +887,9 @@ EXPORT_SYMBOL(end_page_writeback);
  * After completing I/O on a page, call this routine to update the page
  * flags appropriately
  */
-void page_endio(struct page *page, int rw, int err)
+void page_endio(struct page *page, int op, int err)
 {
-	if (rw == READ) {
+	if (!op_is_write(op)) {
 		if (!err) {
 			SetPageUptodate(page);
 		} else {
@@ -897,7 +897,7 @@ void page_endio(struct page *page, int rw, int err)
 			SetPageError(page);
 		}
 		unlock_page(page);
-	} else { /* rw == WRITE */
+	} else {
 		if (err) {
 			SetPageError(page);
 			if (page->mapping)