Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:
 "Another nice round of removing more code than what is added, mostly
  due to Christoph's relentless pursuit of tech debt removal/cleanups.
  This pull request contains:

   - Two series of BFQ improvements (Paolo, Jan, Jia)

   - Block iov_iter improvements (Pavel)

   - bsg error path fix (Pan)

   - blk-mq scheduler improvements (Jan)

   - -EBUSY discard fix (Jan)

   - bvec allocation improvements (Ming, Christoph)

   - bio allocation and init improvements (Christoph)

   - Store bdev pointer in bio instead of gendisk + partno (Christoph)

   - Block trace point cleanups (Christoph)

   - hard read-only vs read-only split (Christoph)

   - Block based swap cleanups (Christoph)

   - Zoned write granularity support (Damien)

   - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)"

* tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits)
  mm: simplify swapdev_block
  sd_zbc: clear zone resources for non-zoned case
  block: introduce blk_queue_clear_zone_settings()
  zonefs: use zone write granularity as block size
  block: introduce zone_write_granularity limit
  block: use blk_queue_set_zoned in add_partition()
  nullb: use blk_queue_set_zoned() to setup zoned devices
  nvme: cleanup zone information initialization
  block: document zone_append_max_bytes attribute
  block: use bi_max_vecs to find the bvec pool
  md/raid10: remove dead code in reshape_request
  block: mark the bio as cloned in bio_iov_bvec_set
  block: set BIO_NO_PAGE_REF in bio_iov_bvec_set
  block: remove a layer of indentation in bio_iov_iter_get_pages
  block: turn the nr_iovecs argument to bio_alloc* into an unsigned short
  block: remove the 1 and 4 vec bvec_slabs entries
  block: streamline bvec_alloc
  block: factor out a bvec_alloc_gfp helper
  block: move struct biovec_slab to bio.c
  block: reuse BIO_INLINE_VECS for integrity bvecs
  ...

fs/block_dev.c

@@ -126,7 +126,6 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
 		bd_abort_claiming(bdev, truncate_bdev_range);
 	return 0;
 }
-EXPORT_SYMBOL(truncate_bdev_range);
 
 static void set_init_blocksize(struct block_device *bdev)
 {
@@ -424,7 +423,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 		dio->size += bio->bi_iter.bi_size;
 		pos += bio->bi_iter.bi_size;
 
-		nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES);
+		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES);
 		if (!nr_pages) {
 			bool polled = false;
 
@@ -489,9 +488,10 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	int nr_pages;
 
-	nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1);
-	if (!nr_pages)
+	if (!iov_iter_count(iter))
 		return 0;
+
+	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES + 1);
 	if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES)
 		return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
 
@@ -688,7 +688,7 @@ int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 	 * i_mutex and doing so causes performance issues with concurrent
 	 * O_SYNC writers to a block device.
 	 */
-	error = blkdev_issue_flush(bdev, GFP_KERNEL);
+	error = blkdev_issue_flush(bdev);
 	if (error == -EOPNOTSUPP)
 		error = 0;
 
@@ -1808,13 +1808,11 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
 		return error;
 
 	/*
-	 * Invalidate again; if someone wandered in and dirtied a page,
-	 * the caller will be given -EBUSY.  The third argument is
-	 * inclusive, so the rounding here is safe.
+	 * Invalidate the page cache again; if someone wandered in and dirtied
+	 * a page, we just discard it - userspace has no way of knowing whether
+	 * the write happened before or after discard completing...
 	 */
-	return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
-					     start >> PAGE_SHIFT,
-					     end >> PAGE_SHIFT);
+	return truncate_bdev_range(bdev, file->f_mode, start, end);
 }
 
 const struct file_operations def_blk_fops = {