btrfs: factor check and flush helpers from __btrfsic_submit_bio

Split out two helpers to make __btrfsic_submit_bio more readable.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/check-integrity.c

@@ -2633,41 +2633,26 @@ static struct btrfsic_dev_state *btrfsic_dev_state_lookup(dev_t dev)
 						  &btrfsic_dev_state_hashtable);
 }
 
-static void __btrfsic_submit_bio(struct bio *bio)
+static void btrfsic_check_write_bio(struct bio *bio, struct btrfsic_dev_state *dev_state)
 {
-	struct btrfsic_dev_state *dev_state;
-
-	if (!btrfsic_is_initialized)
-		return;
-
-	mutex_lock(&btrfsic_mutex);
-	/* since btrfsic_submit_bio() is also called before
-	 * btrfsic_mount(), this might return NULL */
-	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev->bd_dev);
-	if (NULL != dev_state &&
-	    (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
-		int i = 0;
-		u64 dev_bytenr;
-		u64 cur_bytenr;
-		struct bio_vec bvec;
+	unsigned int segs = bio_segments(bio);
+	u64 dev_bytenr = 512 * bio->bi_iter.bi_sector;
+	u64 cur_bytenr = dev_bytenr;
 	struct bvec_iter iter;
-		int bio_is_patched;
+	struct bio_vec bvec;
 	char **mapped_datav;
-		unsigned int segs = bio_segments(bio);
+	int bio_is_patched = 0;
+	int i = 0;
 
-		dev_bytenr = 512 * bio->bi_iter.bi_sector;
-		bio_is_patched = 0;
-		if (dev_state->state->print_mask &
-		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
-			pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
+	if (dev_state->state->print_mask & BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
+		pr_info(
+"submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
 		       bio_op(bio), bio->bi_opf, segs,
 		       bio->bi_iter.bi_sector, dev_bytenr, bio->bi_bdev);
 
-		mapped_datav = kmalloc_array(segs,
-					     sizeof(*mapped_datav), GFP_NOFS);
+	mapped_datav = kmalloc_array(segs, sizeof(*mapped_datav), GFP_NOFS);
 	if (!mapped_datav)
-			goto leave;
-		cur_bytenr = dev_bytenr;
+		return;
 
 	bio_for_each_segment(bvec, bio, iter) {
 		BUG_ON(bvec.bv_len != PAGE_SIZE);
@@ -2680,24 +2665,19 @@ static void __btrfsic_submit_bio(struct bio *bio)
 			       i, cur_bytenr, bvec.bv_len, bvec.bv_offset);
 		cur_bytenr += bvec.bv_len;
 	}
-		btrfsic_process_written_block(dev_state, dev_bytenr,
-					      mapped_datav, segs,
-					      bio, &bio_is_patched,
-					      bio->bi_opf);
+
+	btrfsic_process_written_block(dev_state, dev_bytenr, mapped_datav, segs,
+				      bio, &bio_is_patched, bio->bi_opf);
 	kfree(mapped_datav);
-	} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
-		if (dev_state->state->print_mask &
-		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
+}
+
+static void btrfsic_check_flush_bio(struct bio *bio, struct btrfsic_dev_state *dev_state)
+{
+	if (dev_state->state->print_mask & BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
 		pr_info("submit_bio(rw=%d,0x%x FLUSH, bdev=%p)\n",
 		       bio_op(bio), bio->bi_opf, bio->bi_bdev);
-		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
-			if ((dev_state->state->print_mask &
-			     (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
-			      BTRFSIC_PRINT_MASK_VERBOSE)))
-				pr_info(
-"btrfsic_submit_bio(%pg) with FLUSH but dummy block already in use (ignored)!\n",
-				       dev_state->bdev);
-		} else {
+
+	if (dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
 		struct btrfsic_block *const block =
 			&dev_state->dummy_block_for_bio_bh_flush;
 
@@ -2711,9 +2691,34 @@ static void __btrfsic_submit_bio(struct bio *bio)
 		block->next_in_same_bio = NULL;
 		bio->bi_private = block;
 		bio->bi_end_io = btrfsic_bio_end_io;
+	} else if ((dev_state->state->print_mask &
+		   (BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH |
+		    BTRFSIC_PRINT_MASK_VERBOSE))) {
+		pr_info(
+"btrfsic_submit_bio(%pg) with FLUSH but dummy block already in use (ignored)!\n",
+		       dev_state->bdev);
 	}
+}
+
+static void __btrfsic_submit_bio(struct bio *bio)
+{
+	struct btrfsic_dev_state *dev_state;
+
+	if (!btrfsic_is_initialized)
+		return;
+
+	/*
+	 * We can be called before btrfsic_mount, so there might not be a
+	 * dev_state.
+	 */
+	dev_state = btrfsic_dev_state_lookup(bio->bi_bdev->bd_dev);
+	mutex_lock(&btrfsic_mutex);
+	if (dev_state) {
+		if (bio_op(bio) == REQ_OP_WRITE && bio_has_data(bio))
+			btrfsic_check_write_bio(bio, dev_state);
+		else if (bio->bi_opf & REQ_PREFLUSH)
+			btrfsic_check_flush_bio(bio, dev_state);
 	}
-leave:
 	mutex_unlock(&btrfsic_mutex);
 }