Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 5a46d7f..8efd14e 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2016 CNEX Labs
  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
@@ -25,8 +26,7 @@
  * issued.
  */
 static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
-				sector_t lba, struct ppa_addr ppa,
-				int bio_iter, bool advanced_bio)
+				sector_t lba, struct ppa_addr ppa)
 {
 #ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a cache address */
@@ -34,94 +34,100 @@
 	BUG_ON(!pblk_addr_in_cache(ppa));
 #endif
 
-	return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa,
-						bio_iter, advanced_bio);
+	return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa);
 }
 
-static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
+static int pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
 				 struct bio *bio, sector_t blba,
-				 unsigned long *read_bitmap)
+				 bool *from_cache)
 {
-	struct pblk_sec_meta *meta_list = rqd->meta_list;
-	struct ppa_addr ppas[PBLK_MAX_REQ_ADDRS];
-	int nr_secs = rqd->nr_ppas;
-	bool advanced_bio = false;
-	int i, j = 0;
-
-	pblk_lookup_l2p_seq(pblk, ppas, blba, nr_secs);
-
-	for (i = 0; i < nr_secs; i++) {
-		struct ppa_addr p = ppas[i];
-		sector_t lba = blba + i;
+	void *meta_list = rqd->meta_list;
+	int nr_secs, i;
 
 retry:
-		if (pblk_ppa_empty(p)) {
-			WARN_ON(test_and_set_bit(i, read_bitmap));
-			meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
+	nr_secs = pblk_lookup_l2p_seq(pblk, rqd->ppa_list, blba, rqd->nr_ppas,
+					from_cache);
 
-			if (unlikely(!advanced_bio)) {
-				bio_advance(bio, (i) * PBLK_EXPOSED_PAGE_SIZE);
-				advanced_bio = true;
+	if (!*from_cache)
+		goto end;
+
+	for (i = 0; i < nr_secs; i++) {
+		struct pblk_sec_meta *meta = pblk_get_meta(pblk, meta_list, i);
+		sector_t lba = blba + i;
+
+		if (pblk_ppa_empty(rqd->ppa_list[i])) {
+			__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+			meta->lba = addr_empty;
+		} else if (pblk_addr_in_cache(rqd->ppa_list[i])) {
+			/*
+			 * Try to read from write buffer. The address is later
+			 * checked on the write buffer to prevent retrieving
+			 * overwritten data.
+			 */
+			if (!pblk_read_from_cache(pblk, bio, lba,
+							rqd->ppa_list[i])) {
+				if (i == 0) {
+					/*
+					 * We didn't call with bio_advance()
+					 * yet, so we can just retry.
+					 */
+					goto retry;
+				} else {
+					/*
+					 * We already call bio_advance()
+					 * so we cannot retry and we need
+					 * to quit that function in order
+					 * to allow caller to handle the bio
+					 * splitting in the current sector
+					 * position.
+					 */
+					nr_secs = i;
+					goto end;
+				}
 			}
-
-			goto next;
-		}
-
-		/* Try to read from write buffer. The address is later checked
-		 * on the write buffer to prevent retrieving overwritten data.
-		 */
-		if (pblk_addr_in_cache(p)) {
-			if (!pblk_read_from_cache(pblk, bio, lba, p, i,
-								advanced_bio)) {
-				pblk_lookup_l2p_seq(pblk, &p, lba, 1);
-				goto retry;
-			}
-			WARN_ON(test_and_set_bit(i, read_bitmap));
-			meta_list[i].lba = cpu_to_le64(lba);
-			advanced_bio = true;
+			meta->lba = cpu_to_le64(lba);
 #ifdef CONFIG_NVM_PBLK_DEBUG
 			atomic_long_inc(&pblk->cache_reads);
 #endif
-		} else {
-			/* Read from media non-cached sectors */
-			rqd->ppa_list[j++] = p;
 		}
-
-next:
-		if (advanced_bio)
-			bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
+		bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
 	}
 
+end:
 	if (pblk_io_aligned(pblk, nr_secs))
-		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_SEQUENTIAL);
-	else
-		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+		rqd->is_seq = 1;
 
 #ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(nr_secs, &pblk->inflight_reads);
 #endif
+
+	return nr_secs;
 }
 
 
 static void pblk_read_check_seq(struct pblk *pblk, struct nvm_rq *rqd,
 				sector_t blba)
 {
-	struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
+	void *meta_list = rqd->meta_list;
 	int nr_lbas = rqd->nr_ppas;
 	int i;
 
+	if (!pblk_is_oob_meta_supported(pblk))
+		return;
+
 	for (i = 0; i < nr_lbas; i++) {
-		u64 lba = le64_to_cpu(meta_lba_list[i].lba);
+		struct pblk_sec_meta *meta = pblk_get_meta(pblk, meta_list, i);
+		u64 lba = le64_to_cpu(meta->lba);
 
 		if (lba == ADDR_EMPTY)
 			continue;
 
 		if (lba != blba + i) {
 #ifdef CONFIG_NVM_PBLK_DEBUG
-			struct ppa_addr *p;
+			struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
 
-			p = (nr_lbas == 1) ? &rqd->ppa_list[i] : &rqd->ppa_addr;
-			print_ppa(pblk, p, "seq", i);
+			print_ppa(pblk, &ppa_list[i], "seq", i);
 #endif
 			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
 							lba, (u64)blba + i);
@@ -136,28 +142,31 @@
 static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
 				 u64 *lba_list, int nr_lbas)
 {
-	struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
+	void *meta_lba_list = rqd->meta_list;
 	int i, j;
 
+	if (!pblk_is_oob_meta_supported(pblk))
+		return;
+
 	for (i = 0, j = 0; i < nr_lbas; i++) {
+		struct pblk_sec_meta *meta = pblk_get_meta(pblk,
+							   meta_lba_list, j);
 		u64 lba = lba_list[i];
 		u64 meta_lba;
 
 		if (lba == ADDR_EMPTY)
 			continue;
 
-		meta_lba = le64_to_cpu(meta_lba_list[j].lba);
+		meta_lba = le64_to_cpu(meta->lba);
 
 		if (lba != meta_lba) {
 #ifdef CONFIG_NVM_PBLK_DEBUG
-			struct ppa_addr *p;
-			int nr_ppas = rqd->nr_ppas;
+			struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
 
-			p = (nr_ppas == 1) ? &rqd->ppa_list[j] : &rqd->ppa_addr;
-			print_ppa(pblk, p, "seq", j);
+			print_ppa(pblk, &ppa_list[j], "rnd", j);
 #endif
 			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
-								lba, meta_lba);
+							meta_lba, lba);
 			WARN_ON(1);
 		}
 
@@ -167,28 +176,12 @@
 	WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n");
 }
 
-static void pblk_read_put_rqd_kref(struct pblk *pblk, struct nvm_rq *rqd)
+static void pblk_end_user_read(struct bio *bio, int error)
 {
-	struct ppa_addr *ppa_list;
-	int i;
-
-	ppa_list = (rqd->nr_ppas > 1) ? rqd->ppa_list : &rqd->ppa_addr;
-
-	for (i = 0; i < rqd->nr_ppas; i++) {
-		struct ppa_addr ppa = ppa_list[i];
-		struct pblk_line *line;
-
-		line = &pblk->lines[pblk_ppa_to_line(ppa)];
-		kref_put(&line->ref, pblk_line_put_wq);
-	}
-}
-
-static void pblk_end_user_read(struct bio *bio)
-{
-#ifdef CONFIG_NVM_PBLK_DEBUG
-	WARN_ONCE(bio->bi_status, "pblk: corrupted read bio\n");
-#endif
-	bio_endio(bio);
+	if (error && error != NVM_RSP_WARN_HIGHECC)
+		bio_io_error(bio);
+	else
+		bio_endio(bio);
 }
 
 static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
@@ -205,12 +198,10 @@
 		pblk_log_read_err(pblk, rqd);
 
 	pblk_read_check_seq(pblk, rqd, r_ctx->lba);
-
-	if (int_bio)
-		bio_put(int_bio);
+	bio_put(int_bio);
 
 	if (put_line)
-		pblk_read_put_rqd_kref(pblk, rqd);
+		pblk_rq_to_line_put(pblk, rqd);
 
 #ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
@@ -227,187 +218,17 @@
 	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 	struct bio *bio = (struct bio *)r_ctx->private;
 
-	pblk_end_user_read(bio);
+	pblk_end_user_read(bio, rqd->error);
 	__pblk_end_io_read(pblk, rqd, true);
 }
 
-static void pblk_end_partial_read(struct nvm_rq *rqd)
-{
-	struct pblk *pblk = rqd->private;
-	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
-	struct pblk_pr_ctx *pr_ctx = r_ctx->private;
-	struct bio *new_bio = rqd->bio;
-	struct bio *bio = pr_ctx->orig_bio;
-	struct bio_vec src_bv, dst_bv;
-	struct pblk_sec_meta *meta_list = rqd->meta_list;
-	int bio_init_idx = pr_ctx->bio_init_idx;
-	unsigned long *read_bitmap = pr_ctx->bitmap;
-	int nr_secs = pr_ctx->orig_nr_secs;
-	int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
-	__le64 *lba_list_mem, *lba_list_media;
-	void *src_p, *dst_p;
-	int hole, i;
-
-	if (unlikely(nr_holes == 1)) {
-		struct ppa_addr ppa;
-
-		ppa = rqd->ppa_addr;
-		rqd->ppa_list = pr_ctx->ppa_ptr;
-		rqd->dma_ppa_list = pr_ctx->dma_ppa_list;
-		rqd->ppa_list[0] = ppa;
-	}
-
-	/* Re-use allocated memory for intermediate lbas */
-	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
-	lba_list_media = (((void *)rqd->ppa_list) + 2 * pblk_dma_ppa_size);
-
-	for (i = 0; i < nr_secs; i++) {
-		lba_list_media[i] = meta_list[i].lba;
-		meta_list[i].lba = lba_list_mem[i];
-	}
-
-	/* Fill the holes in the original bio */
-	i = 0;
-	hole = find_first_zero_bit(read_bitmap, nr_secs);
-	do {
-		int line_id = pblk_ppa_to_line(rqd->ppa_list[i]);
-		struct pblk_line *line = &pblk->lines[line_id];
-
-		kref_put(&line->ref, pblk_line_put);
-
-		meta_list[hole].lba = lba_list_media[i];
-
-		src_bv = new_bio->bi_io_vec[i++];
-		dst_bv = bio->bi_io_vec[bio_init_idx + hole];
-
-		src_p = kmap_atomic(src_bv.bv_page);
-		dst_p = kmap_atomic(dst_bv.bv_page);
-
-		memcpy(dst_p + dst_bv.bv_offset,
-			src_p + src_bv.bv_offset,
-			PBLK_EXPOSED_PAGE_SIZE);
-
-		kunmap_atomic(src_p);
-		kunmap_atomic(dst_p);
-
-		mempool_free(src_bv.bv_page, &pblk->page_bio_pool);
-
-		hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
-	} while (hole < nr_secs);
-
-	bio_put(new_bio);
-	kfree(pr_ctx);
-
-	/* restore original request */
-	rqd->bio = NULL;
-	rqd->nr_ppas = nr_secs;
-
-	bio_endio(bio);
-	__pblk_end_io_read(pblk, rqd, false);
-}
-
-static int pblk_setup_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
-			    unsigned int bio_init_idx,
-			    unsigned long *read_bitmap,
-			    int nr_holes)
-{
-	struct pblk_sec_meta *meta_list = rqd->meta_list;
-	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
-	struct pblk_pr_ctx *pr_ctx;
-	struct bio *new_bio, *bio = r_ctx->private;
-	__le64 *lba_list_mem;
-	int nr_secs = rqd->nr_ppas;
-	int i;
-
-	/* Re-use allocated memory for intermediate lbas */
-	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
-
-	new_bio = bio_alloc(GFP_KERNEL, nr_holes);
-
-	if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
-		goto fail_bio_put;
-
-	if (nr_holes != new_bio->bi_vcnt) {
-		WARN_ONCE(1, "pblk: malformed bio\n");
-		goto fail_free_pages;
-	}
-
-	pr_ctx = kmalloc(sizeof(struct pblk_pr_ctx), GFP_KERNEL);
-	if (!pr_ctx)
-		goto fail_free_pages;
-
-	for (i = 0; i < nr_secs; i++)
-		lba_list_mem[i] = meta_list[i].lba;
-
-	new_bio->bi_iter.bi_sector = 0; /* internal bio */
-	bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
-
-	rqd->bio = new_bio;
-	rqd->nr_ppas = nr_holes;
-	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
-
-	pr_ctx->ppa_ptr = NULL;
-	pr_ctx->orig_bio = bio;
-	bitmap_copy(pr_ctx->bitmap, read_bitmap, NVM_MAX_VLBA);
-	pr_ctx->bio_init_idx = bio_init_idx;
-	pr_ctx->orig_nr_secs = nr_secs;
-	r_ctx->private = pr_ctx;
-
-	if (unlikely(nr_holes == 1)) {
-		pr_ctx->ppa_ptr = rqd->ppa_list;
-		pr_ctx->dma_ppa_list = rqd->dma_ppa_list;
-		rqd->ppa_addr = rqd->ppa_list[0];
-	}
-	return 0;
-
-fail_free_pages:
-	pblk_bio_free_pages(pblk, new_bio, 0, new_bio->bi_vcnt);
-fail_bio_put:
-	bio_put(new_bio);
-
-	return -ENOMEM;
-}
-
-static int pblk_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
-				 unsigned int bio_init_idx,
-				 unsigned long *read_bitmap, int nr_secs)
-{
-	int nr_holes;
-	int ret;
-
-	nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
-
-	if (pblk_setup_partial_read(pblk, rqd, bio_init_idx, read_bitmap,
-				    nr_holes))
-		return NVM_IO_ERR;
-
-	rqd->end_io = pblk_end_partial_read;
-
-	ret = pblk_submit_io(pblk, rqd);
-	if (ret) {
-		bio_put(rqd->bio);
-		pblk_err(pblk, "partial read IO submission failed\n");
-		goto err;
-	}
-
-	return NVM_IO_OK;
-
-err:
-	pblk_err(pblk, "failed to perform partial read\n");
-
-	/* Free allocated pages in new bio */
-	pblk_bio_free_pages(pblk, rqd->bio, 0, rqd->bio->bi_vcnt);
-	__pblk_end_io_read(pblk, rqd, false);
-	return NVM_IO_ERR;
-}
-
 static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd, struct bio *bio,
-			 sector_t lba, unsigned long *read_bitmap)
+			 sector_t lba, bool *from_cache)
 {
-	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct pblk_sec_meta *meta = pblk_get_meta(pblk, rqd->meta_list, 0);
 	struct ppa_addr ppa;
 
-	pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+	pblk_lookup_l2p_seq(pblk, &ppa, lba, 1, from_cache);
 
 #ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_inc(&pblk->inflight_reads);
@@ -415,8 +236,9 @@
 
 retry:
 	if (pblk_ppa_empty(ppa)) {
-		WARN_ON(test_and_set_bit(0, read_bitmap));
-		meta_list[0].lba = cpu_to_le64(ADDR_EMPTY);
+		__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
+
+		meta->lba = addr_empty;
 		return;
 	}
 
@@ -424,13 +246,12 @@
 	 * write buffer to prevent retrieving overwritten data.
 	 */
 	if (pblk_addr_in_cache(ppa)) {
-		if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0, 1)) {
-			pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
+		if (!pblk_read_from_cache(pblk, bio, lba, ppa)) {
+			pblk_lookup_l2p_seq(pblk, &ppa, lba, 1, from_cache);
 			goto retry;
 		}
 
-		WARN_ON(test_and_set_bit(0, read_bitmap));
-		meta_list[0].lba = cpu_to_le64(lba);
+		meta->lba = cpu_to_le64(lba);
 
 #ifdef CONFIG_NVM_PBLK_DEBUG
 		atomic_long_inc(&pblk->cache_reads);
@@ -438,121 +259,101 @@
 	} else {
 		rqd->ppa_addr = ppa;
 	}
-
-	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
 }
 
-int pblk_submit_read(struct pblk *pblk, struct bio *bio)
+void pblk_submit_read(struct pblk *pblk, struct bio *bio)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct request_queue *q = dev->q;
 	sector_t blba = pblk_get_lba(bio);
 	unsigned int nr_secs = pblk_get_secs(bio);
+	bool from_cache;
 	struct pblk_g_ctx *r_ctx;
 	struct nvm_rq *rqd;
-	unsigned int bio_init_idx;
-	DECLARE_BITMAP(read_bitmap, NVM_MAX_VLBA);
-	int ret = NVM_IO_ERR;
-
-	/* logic error: lba out-of-bounds. Ignore read request */
-	if (blba >= pblk->rl.nr_secs || nr_secs > PBLK_MAX_REQ_ADDRS) {
-		WARN(1, "pblk: read lba out of bounds (lba:%llu, nr:%d)\n",
-					(unsigned long long)blba, nr_secs);
-		return NVM_IO_ERR;
-	}
+	struct bio *int_bio, *split_bio;
 
 	generic_start_io_acct(q, REQ_OP_READ, bio_sectors(bio),
 			      &pblk->disk->part0);
 
-	bitmap_zero(read_bitmap, nr_secs);
-
 	rqd = pblk_alloc_rqd(pblk, PBLK_READ);
 
 	rqd->opcode = NVM_OP_PREAD;
 	rqd->nr_ppas = nr_secs;
-	rqd->bio = NULL; /* cloned bio if needed */
 	rqd->private = pblk;
 	rqd->end_io = pblk_end_io_read;
 
 	r_ctx = nvm_rq_to_pdu(rqd);
 	r_ctx->start_time = jiffies;
 	r_ctx->lba = blba;
-	r_ctx->private = bio; /* original bio */
 
-	/* Save the index for this bio's start. This is needed in case
-	 * we need to fill a partial read.
+	if (pblk_alloc_rqd_meta(pblk, rqd)) {
+		bio_io_error(bio);
+		pblk_free_rqd(pblk, rqd, PBLK_READ);
+		return;
+	}
+
+	/* Clone read bio to deal internally with:
+	 * -read errors when reading from drive
+	 * -bio_advance() calls during cache reads
 	 */
-	bio_init_idx = pblk_get_bi_idx(bio);
+	int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set);
 
-	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-							&rqd->dma_meta_list);
-	if (!rqd->meta_list) {
-		pblk_err(pblk, "not able to allocate ppa list\n");
-		goto fail_rqd_free;
-	}
+	if (nr_secs > 1)
+		nr_secs = pblk_read_ppalist_rq(pblk, rqd, int_bio, blba,
+						&from_cache);
+	else
+		pblk_read_rq(pblk, rqd, int_bio, blba, &from_cache);
 
-	if (nr_secs > 1) {
-		rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
-		rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
+split_retry:
+	r_ctx->private = bio; /* original bio */
+	rqd->bio = int_bio; /* internal bio */
 
-		pblk_read_ppalist_rq(pblk, rqd, bio, blba, read_bitmap);
-	} else {
-		pblk_read_rq(pblk, rqd, bio, blba, read_bitmap);
-	}
-
-	if (bitmap_full(read_bitmap, nr_secs)) {
+	if (from_cache && nr_secs == rqd->nr_ppas) {
+		/* All data was read from cache, we can complete the IO. */
+		pblk_end_user_read(bio, 0);
 		atomic_inc(&pblk->inflight_io);
 		__pblk_end_io_read(pblk, rqd, false);
-		return NVM_IO_DONE;
-	}
+	} else if (nr_secs != rqd->nr_ppas) {
+		/* The read bio request could be partially filled by the write
+		 * buffer, but there are some holes that need to be read from
+		 * the drive. In order to handle this, we will use block layer
+		 * mechanism to split this request in to smaller ones and make
+		 * a chain of it.
+		 */
+		split_bio = bio_split(bio, nr_secs * NR_PHY_IN_LOG, GFP_KERNEL,
+					&pblk_bio_set);
+		bio_chain(split_bio, bio);
+		generic_make_request(bio);
 
-	/* All sectors are to be read from the device */
-	if (bitmap_empty(read_bitmap, rqd->nr_ppas)) {
-		struct bio *int_bio = NULL;
+		/* New bio contains first N sectors of the previous one, so
+		 * we can continue to use existing rqd, but we need to shrink
+		 * the number of PPAs in it. New bio is also guaranteed that
+		 * it contains only either data from cache or from drive, newer
+		 * mix of them.
+		 */
+		bio = split_bio;
+		rqd->nr_ppas = nr_secs;
+		if (rqd->nr_ppas == 1)
+			rqd->ppa_addr = rqd->ppa_list[0];
 
-		/* Clone read bio to deal with read errors internally */
+		/* Recreate int_bio - existing might have some needed internal
+		 * fields modified already.
+		 */
+		bio_put(int_bio);
 		int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set);
-		if (!int_bio) {
-			pblk_err(pblk, "could not clone read bio\n");
-			goto fail_end_io;
-		}
-
-		rqd->bio = int_bio;
-
-		if (pblk_submit_io(pblk, rqd)) {
-			pblk_err(pblk, "read IO submission failed\n");
-			ret = NVM_IO_ERR;
-			goto fail_end_io;
-		}
-
-		return NVM_IO_OK;
+		goto split_retry;
+	} else if (pblk_submit_io(pblk, rqd, NULL)) {
+		/* Submitting IO to drive failed, let's report an error */
+		rqd->error = -ENODEV;
+		pblk_end_io_read(rqd);
 	}
-
-	/* The read bio request could be partially filled by the write buffer,
-	 * but there are some holes that need to be read from the drive.
-	 */
-	ret = pblk_partial_read_bio(pblk, rqd, bio_init_idx, read_bitmap,
-				    nr_secs);
-	if (ret)
-		goto fail_meta_free;
-
-	return NVM_IO_OK;
-
-fail_meta_free:
-	nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
-fail_rqd_free:
-	pblk_free_rqd(pblk, rqd, PBLK_READ);
-	return ret;
-fail_end_io:
-	__pblk_end_io_read(pblk, rqd, false);
-	return ret;
 }
 
 static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
 			      struct pblk_line *line, u64 *lba_list,
 			      u64 *paddr_list_gc, unsigned int nr_secs)
 {
-	struct ppa_addr ppa_list_l2p[PBLK_MAX_REQ_ADDRS];
+	struct ppa_addr ppa_list_l2p[NVM_MAX_VLBA];
 	struct ppa_addr ppa_gc;
 	int valid_secs = 0;
 	int i;
@@ -590,7 +391,7 @@
 		goto out;
 
 	/* logic error: lba out-of-bounds */
-	if (lba >= pblk->rl.nr_secs) {
+	if (lba >= pblk->capacity) {
 		WARN(1, "pblk: read lba out of bounds\n");
 		goto out;
 	}
@@ -616,24 +417,16 @@
 
 int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 {
-	struct nvm_tgt_dev *dev = pblk->dev;
-	struct nvm_geo *geo = &dev->geo;
-	struct bio *bio;
 	struct nvm_rq rqd;
-	int data_len;
 	int ret = NVM_IO_OK;
 
 	memset(&rqd, 0, sizeof(struct nvm_rq));
 
-	rqd.meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
-							&rqd.dma_meta_list);
-	if (!rqd.meta_list)
-		return -ENOMEM;
+	ret = pblk_alloc_rqd_meta(pblk, &rqd);
+	if (ret)
+		return ret;
 
 	if (gc_rq->nr_secs > 1) {
-		rqd.ppa_list = rqd.meta_list + pblk_dma_meta_size;
-		rqd.dma_ppa_list = rqd.dma_meta_list + pblk_dma_meta_size;
-
 		gc_rq->secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, gc_rq->line,
 							gc_rq->lba_list,
 							gc_rq->paddr_list,
@@ -649,27 +442,12 @@
 	if (!(gc_rq->secs_to_gc))
 		goto out;
 
-	data_len = (gc_rq->secs_to_gc) * geo->csecs;
-	bio = pblk_bio_map_addr(pblk, gc_rq->data, gc_rq->secs_to_gc, data_len,
-						PBLK_VMALLOC_META, GFP_KERNEL);
-	if (IS_ERR(bio)) {
-		pblk_err(pblk, "could not allocate GC bio (%lu)\n",
-				PTR_ERR(bio));
-		goto err_free_dma;
-	}
-
-	bio->bi_iter.bi_sector = 0; /* internal bio */
-	bio_set_op_attrs(bio, REQ_OP_READ, 0);
-
 	rqd.opcode = NVM_OP_PREAD;
 	rqd.nr_ppas = gc_rq->secs_to_gc;
-	rqd.flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
-	rqd.bio = bio;
 
-	if (pblk_submit_io_sync(pblk, &rqd)) {
+	if (pblk_submit_io_sync(pblk, &rqd, gc_rq->data)) {
 		ret = -EIO;
-		pblk_err(pblk, "GC read request failed\n");
-		goto err_free_bio;
+		goto err_free_dma;
 	}
 
 	pblk_read_check_rand(pblk, &rqd, gc_rq->lba_list, gc_rq->nr_secs);
@@ -690,12 +468,10 @@
 #endif
 
 out:
-	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+	pblk_free_rqd_meta(pblk, &rqd);
 	return ret;
 
-err_free_bio:
-	bio_put(bio);
 err_free_dma:
-	nvm_dev_dma_free(dev->parent, rqd.meta_list, rqd.dma_meta_list);
+	pblk_free_rqd_meta(pblk, &rqd);
 	return ret;
 }