drivers/nvdimm/blk.c - linux - Git at Google

 /*
  * NVDIMM Block Window Driver
  * Copyright (c) 2014, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  */

 #include <linux/blkdev.h>
 #include <linux/fs.h>
 #include <linux/genhd.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/nd.h>
 #include <linux/sizes.h>
 #include "nd.h"

 static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
 {
 	return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
 }

 static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
 {
 	return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
 }

 static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
 {
 	return nsblk->lbasize - nsblk_meta_size(nsblk);
 }

 static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
 				resource_size_t ns_offset, unsigned int len)
 {
 	int i;

 	for (i = 0; i < nsblk->num_resources; i++) {
 		if (ns_offset < resource_size(nsblk->res[i])) {
 			if (ns_offset + len > resource_size(nsblk->res[i])) {
 				dev_WARN_ONCE(&nsblk->common.dev, 1,
 					"illegal request\n");
 				return SIZE_MAX;
 			}
 			return nsblk->res[i]->start + ns_offset;
 		}
 		ns_offset -= resource_size(nsblk->res[i]);
 	}

 	dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
 	return SIZE_MAX;
 }

 static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
 {
 	struct nd_region *nd_region;
 	struct device *parent;

 	parent = nsblk->common.dev.parent;
 	nd_region = container_of(parent, struct nd_region, dev);
 	return container_of(nd_region, struct nd_blk_region, nd_region);
 }

 #ifdef CONFIG_BLK_DEV_INTEGRITY
 static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
 		struct bio_integrity_payload *bip, u64 lba, int rw)
 {
 	struct nd_blk_region *ndbr = to_ndbr(nsblk);
 	unsigned int len = nsblk_meta_size(nsblk);
 	resource_size_t	dev_offset, ns_offset;
 	u32 internal_lbasize, sector_size;
 	int err = 0;

 	internal_lbasize = nsblk_internal_lbasize(nsblk);
 	sector_size = nsblk_sector_size(nsblk);
 	ns_offset = lba * internal_lbasize + sector_size;
 	dev_offset = to_dev_offset(nsblk, ns_offset, len);
 	if (dev_offset == SIZE_MAX)
 		return -EIO;

 	while (len) {
 		unsigned int cur_len;
 		struct bio_vec bv;
 		void *iobuf;

 		bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
 		/*
 		 * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
 		 * .bv_offset already adjusted for iter->bi_bvec_done, and we
 		 * can use those directly
 		 */

 		cur_len = min(len, bv.bv_len);
 		iobuf = kmap_atomic(bv.bv_page);
 		err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
 				cur_len, rw);
 		kunmap_atomic(iobuf);
 		if (err)
 			return err;

 		len -= cur_len;
 		dev_offset += cur_len;
 		bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
 	}

 	return err;
 }

 #else /* CONFIG_BLK_DEV_INTEGRITY */
 static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
 		struct bio_integrity_payload *bip, u64 lba, int rw)
 {
 	return 0;
 }
 #endif

 static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
 		struct bio_integrity_payload *bip, struct page *page,
 		unsigned int len, unsigned int off, int rw, sector_t sector)
 {
 	struct nd_blk_region *ndbr = to_ndbr(nsblk);
 	resource_size_t	dev_offset, ns_offset;
 	u32 internal_lbasize, sector_size;
 	int err = 0;
 	void *iobuf;
 	u64 lba;

 	internal_lbasize = nsblk_internal_lbasize(nsblk);
 	sector_size = nsblk_sector_size(nsblk);
 	while (len) {
 		unsigned int cur_len;

 		/*
 		 * If we don't have an integrity payload, we don't have to
 		 * split the bvec into sectors, as this would cause unnecessary
 		 * Block Window setup/move steps. the do_io routine is capable
 		 * of handling len <= PAGE_SIZE.
 		 */
 		cur_len = bip ? min(len, sector_size) : len;

 		lba = div_u64(sector << SECTOR_SHIFT, sector_size);
 		ns_offset = lba * internal_lbasize;
 		dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
 		if (dev_offset == SIZE_MAX)
 			return -EIO;

 		iobuf = kmap_atomic(page);
 		err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
 		kunmap_atomic(iobuf);
 		if (err)
 			return err;

 		if (bip) {
 			err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
 			if (err)
 				return err;
 		}
 		len -= cur_len;
 		off += cur_len;
 		sector += sector_size >> SECTOR_SHIFT;
 	}

 	return err;
 }

 static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
 {
 	struct bio_integrity_payload *bip;
 	struct nd_namespace_blk *nsblk;
 	struct bvec_iter iter;
 	unsigned long start;
 	struct bio_vec bvec;
 	int err = 0, rw;
 	bool do_acct;

 	/*
 	 * bio_integrity_enabled also checks if the bio already has an
 	 * integrity payload attached. If it does, we *don't* do a
 	 * bio_integrity_prep here - the payload has been generated by
 	 * another kernel subsystem, and we just pass it through.
 	 */
 	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
 		bio->bi_status = BLK_STS_IOERR;
 		goto out;
 	}

 	bip = bio_integrity(bio);
 	nsblk = q->queuedata;
 	rw = bio_data_dir(bio);
 	do_acct = nd_iostat_start(bio, &start);
 	bio_for_each_segment(bvec, bio, iter) {
 		unsigned int len = bvec.bv_len;

 		BUG_ON(len > PAGE_SIZE);
 		err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
 				bvec.bv_offset, rw, iter.bi_sector);
 		if (err) {
 			dev_dbg(&nsblk->common.dev,
 					"io error in %s sector %lld, len %d,\n",
 					(rw == READ) ? "READ" : "WRITE",
 					(unsigned long long) iter.bi_sector, len);
 			bio->bi_status = errno_to_blk_status(err);
 			break;
 		}
 	}
 	if (do_acct)
 		nd_iostat_end(bio, start);

  out:
 	bio_endio(bio);
 	return BLK_QC_T_NONE;
 }

 static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
 		resource_size_t offset, void *iobuf, size_t n, int rw,
 		unsigned long flags)
 {
 	struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
 	struct nd_blk_region *ndbr = to_ndbr(nsblk);
 	resource_size_t	dev_offset;

 	dev_offset = to_dev_offset(nsblk, offset, n);

 	if (unlikely(offset + n > nsblk->size)) {
 		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 		return -EFAULT;
 	}

 	if (dev_offset == SIZE_MAX)
 		return -EIO;

 	return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
 }

 static const struct block_device_operations nd_blk_fops = {
 	.owner = THIS_MODULE,
 	.revalidate_disk = nvdimm_revalidate_disk,
 };

 static void nd_blk_release_queue(void *q)
 {
 	blk_cleanup_queue(q);
 }

 static void nd_blk_release_disk(void *disk)
 {
 	del_gendisk(disk);
 	put_disk(disk);
 }

 static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
 {
 	struct device *dev = &nsblk->common.dev;
 	resource_size_t available_disk_size;
 	struct request_queue *q;
 	struct gendisk *disk;
 	u64 internal_nlba;

 	internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
 	available_disk_size = internal_nlba * nsblk_sector_size(nsblk);

 	q = blk_alloc_queue(GFP_KERNEL);
 	if (!q)
 		return -ENOMEM;
 	if (devm_add_action_or_reset(dev, nd_blk_release_queue, q))
 		return -ENOMEM;

 	blk_queue_make_request(q, nd_blk_make_request);
 	blk_queue_max_hw_sectors(q, UINT_MAX);
 	blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
 	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
 	q->queuedata = nsblk;

 	disk = alloc_disk(0);
 	if (!disk)
 		return -ENOMEM;

 	disk->first_minor	= 0;
 	disk->fops		= &nd_blk_fops;
 	disk->queue		= q;
 	disk->flags		= GENHD_FL_EXT_DEVT;
 	nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
 	set_capacity(disk, 0);
 	device_add_disk(dev, disk);

 	if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
 		return -ENOMEM;

 	if (nsblk_meta_size(nsblk)) {
 		int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));

 		if (rc)
 			return rc;
 	}

 	set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
 	revalidate_disk(disk);
 	return 0;
 }

 static int nd_blk_probe(struct device *dev)
 {
 	struct nd_namespace_common *ndns;
 	struct nd_namespace_blk *nsblk;

 	ndns = nvdimm_namespace_common_probe(dev);
 	if (IS_ERR(ndns))
 		return PTR_ERR(ndns);

 	nsblk = to_nd_namespace_blk(&ndns->dev);
 	nsblk->size = nvdimm_namespace_capacity(ndns);
 	dev_set_drvdata(dev, nsblk);

 	ndns->rw_bytes = nsblk_rw_bytes;
 	if (is_nd_btt(dev))
 		return nvdimm_namespace_attach_btt(ndns);
 	else if (nd_btt_probe(dev, ndns) == 0) {
 		/* we'll come back as btt-blk */
 		return -ENXIO;
 	} else
 		return nsblk_attach_disk(nsblk);
 }

 static int nd_blk_remove(struct device *dev)
 {
 	if (is_nd_btt(dev))
 		nvdimm_namespace_detach_btt(to_nd_btt(dev));
 	return 0;
 }

 static struct nd_device_driver nd_blk_driver = {
 	.probe = nd_blk_probe,
 	.remove = nd_blk_remove,
 	.drv = {
 		.name = "nd_blk",
 	},
 	.type = ND_DRIVER_NAMESPACE_BLK,
 };

 static int __init nd_blk_init(void)
 {
 	return nd_driver_register(&nd_blk_driver);
 }

 static void __exit nd_blk_exit(void)
 {
 	driver_unregister(&nd_blk_driver.drv);
 }

 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
 module_init(nd_blk_init);
 module_exit(nd_blk_exit);
	/*
	* NVDIMM Block Window Driver
	* Copyright (c) 2014, Intel Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*/

	#include <linux/blkdev.h>
	#include <linux/fs.h>
	#include <linux/genhd.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/nd.h>
	#include <linux/sizes.h>
	#include "nd.h"

	static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
	{
	return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
	}

	static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
	{
	return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
	}

	static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
	{
	return nsblk->lbasize - nsblk_meta_size(nsblk);
	}

	static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
	resource_size_t ns_offset, unsigned int len)
	{
	int i;

	for (i = 0; i < nsblk->num_resources; i++) {
	if (ns_offset < resource_size(nsblk->res[i])) {
	if (ns_offset + len > resource_size(nsblk->res[i])) {
	dev_WARN_ONCE(&nsblk->common.dev, 1,
	"illegal request\n");
	return SIZE_MAX;
	}
	return nsblk->res[i]->start + ns_offset;
	}
	ns_offset -= resource_size(nsblk->res[i]);
	}

	dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
	return SIZE_MAX;
	}

	static struct nd_blk_region to_ndbr(struct nd_namespace_blk nsblk)
	{
	struct nd_region *nd_region;
	struct device *parent;

	parent = nsblk->common.dev.parent;
	nd_region = container_of(parent, struct nd_region, dev);
	return container_of(nd_region, struct nd_blk_region, nd_region);
	}

	#ifdef CONFIG_BLK_DEV_INTEGRITY
	static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
	struct bio_integrity_payload *bip, u64 lba, int rw)
	{
	struct nd_blk_region *ndbr = to_ndbr(nsblk);
	unsigned int len = nsblk_meta_size(nsblk);
	resource_size_t dev_offset, ns_offset;
	u32 internal_lbasize, sector_size;
	int err = 0;

	internal_lbasize = nsblk_internal_lbasize(nsblk);
	sector_size = nsblk_sector_size(nsblk);
	ns_offset = lba * internal_lbasize + sector_size;
	dev_offset = to_dev_offset(nsblk, ns_offset, len);
	if (dev_offset == SIZE_MAX)
	return -EIO;

	while (len) {
	unsigned int cur_len;
	struct bio_vec bv;
	void *iobuf;

	bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
	/*
	* The 'bv' obtained from bvec_iter_bvec has its .bv_len and
	* .bv_offset already adjusted for iter->bi_bvec_done, and we
	* can use those directly
	*/

	cur_len = min(len, bv.bv_len);
	iobuf = kmap_atomic(bv.bv_page);
	err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
	cur_len, rw);
	kunmap_atomic(iobuf);
	if (err)
	return err;

	len -= cur_len;
	dev_offset += cur_len;
	bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
	}

	return err;
	}

	#else /* CONFIG_BLK_DEV_INTEGRITY */
	static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
	struct bio_integrity_payload *bip, u64 lba, int rw)
	{
	return 0;
	}
	#endif

	static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
	struct bio_integrity_payload bip, struct page page,
	unsigned int len, unsigned int off, int rw, sector_t sector)
	{
	struct nd_blk_region *ndbr = to_ndbr(nsblk);
	resource_size_t dev_offset, ns_offset;
	u32 internal_lbasize, sector_size;
	int err = 0;
	void *iobuf;
	u64 lba;

	internal_lbasize = nsblk_internal_lbasize(nsblk);
	sector_size = nsblk_sector_size(nsblk);
	while (len) {
	unsigned int cur_len;

	/*
	* If we don't have an integrity payload, we don't have to
	* split the bvec into sectors, as this would cause unnecessary
	* Block Window setup/move steps. the do_io routine is capable
	* of handling len <= PAGE_SIZE.
	*/
	cur_len = bip ? min(len, sector_size) : len;

	lba = div_u64(sector << SECTOR_SHIFT, sector_size);
	ns_offset = lba * internal_lbasize;
	dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
	if (dev_offset == SIZE_MAX)
	return -EIO;

	iobuf = kmap_atomic(page);
	err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
	kunmap_atomic(iobuf);
	if (err)
	return err;

	if (bip) {
	err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
	if (err)
	return err;
	}
	len -= cur_len;
	off += cur_len;
	sector += sector_size >> SECTOR_SHIFT;
	}

	return err;
	}

	static blk_qc_t nd_blk_make_request(struct request_queue q, struct bio bio)
	{
	struct bio_integrity_payload *bip;
	struct nd_namespace_blk *nsblk;
	struct bvec_iter iter;
	unsigned long start;
	struct bio_vec bvec;
	int err = 0, rw;
	bool do_acct;

	/*
	* bio_integrity_enabled also checks if the bio already has an
	* integrity payload attached. If it does, we don't do a
	* bio_integrity_prep here - the payload has been generated by
	* another kernel subsystem, and we just pass it through.
	*/
	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
	bio->bi_status = BLK_STS_IOERR;
	goto out;
	}

	bip = bio_integrity(bio);
	nsblk = q->queuedata;
	rw = bio_data_dir(bio);
	do_acct = nd_iostat_start(bio, &start);
	bio_for_each_segment(bvec, bio, iter) {
	unsigned int len = bvec.bv_len;

	BUG_ON(len > PAGE_SIZE);
	err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
	bvec.bv_offset, rw, iter.bi_sector);
	if (err) {
	dev_dbg(&nsblk->common.dev,
	"io error in %s sector %lld, len %d,\n",
	(rw == READ) ? "READ" : "WRITE",
	(unsigned long long) iter.bi_sector, len);
	bio->bi_status = errno_to_blk_status(err);
	break;
	}
	}
	if (do_acct)
	nd_iostat_end(bio, start);

	out:
	bio_endio(bio);
	return BLK_QC_T_NONE;
	}

	static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
	resource_size_t offset, void *iobuf, size_t n, int rw,
	unsigned long flags)
	{
	struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
	struct nd_blk_region *ndbr = to_ndbr(nsblk);
	resource_size_t dev_offset;

	dev_offset = to_dev_offset(nsblk, offset, n);

	if (unlikely(offset + n > nsblk->size)) {
	dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
	return -EFAULT;
	}

	if (dev_offset == SIZE_MAX)
	return -EIO;

	return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
	}

	static const struct block_device_operations nd_blk_fops = {
	.owner = THIS_MODULE,
	.revalidate_disk = nvdimm_revalidate_disk,
	};

	static void nd_blk_release_queue(void *q)
	{
	blk_cleanup_queue(q);
	}

	static void nd_blk_release_disk(void *disk)
	{
	del_gendisk(disk);
	put_disk(disk);
	}

	static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
	{
	struct device *dev = &nsblk->common.dev;
	resource_size_t available_disk_size;
	struct request_queue *q;
	struct gendisk *disk;
	u64 internal_nlba;

	internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
	available_disk_size = internal_nlba * nsblk_sector_size(nsblk);

	q = blk_alloc_queue(GFP_KERNEL);
	if (!q)
	return -ENOMEM;
	if (devm_add_action_or_reset(dev, nd_blk_release_queue, q))
	return -ENOMEM;

	blk_queue_make_request(q, nd_blk_make_request);
	blk_queue_max_hw_sectors(q, UINT_MAX);
	blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
	q->queuedata = nsblk;

	disk = alloc_disk(0);
	if (!disk)
	return -ENOMEM;

	disk->first_minor = 0;
	disk->fops = &nd_blk_fops;
	disk->queue = q;
	disk->flags = GENHD_FL_EXT_DEVT;
	nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
	set_capacity(disk, 0);
	device_add_disk(dev, disk);

	if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
	return -ENOMEM;

	if (nsblk_meta_size(nsblk)) {
	int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));

	if (rc)
	return rc;
	}

	set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
	revalidate_disk(disk);
	return 0;
	}

	static int nd_blk_probe(struct device *dev)
	{
	struct nd_namespace_common *ndns;
	struct nd_namespace_blk *nsblk;

	ndns = nvdimm_namespace_common_probe(dev);
	if (IS_ERR(ndns))
	return PTR_ERR(ndns);

	nsblk = to_nd_namespace_blk(&ndns->dev);
	nsblk->size = nvdimm_namespace_capacity(ndns);
	dev_set_drvdata(dev, nsblk);

	ndns->rw_bytes = nsblk_rw_bytes;
	if (is_nd_btt(dev))
	return nvdimm_namespace_attach_btt(ndns);
	else if (nd_btt_probe(dev, ndns) == 0) {
	/* we'll come back as btt-blk */
	return -ENXIO;
	} else
	return nsblk_attach_disk(nsblk);
	}

	static int nd_blk_remove(struct device *dev)
	{
	if (is_nd_btt(dev))
	nvdimm_namespace_detach_btt(to_nd_btt(dev));
	return 0;
	}

	static struct nd_device_driver nd_blk_driver = {
	.probe = nd_blk_probe,
	.remove = nd_blk_remove,
	.drv = {
	.name = "nd_blk",
	},
	.type = ND_DRIVER_NAMESPACE_BLK,
	};

	static int __init nd_blk_init(void)
	{
	return nd_driver_register(&nd_blk_driver);
	}

	static void __exit nd_blk_exit(void)
	{
	driver_unregister(&nd_blk_driver.drv);
	}

	MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
	module_init(nd_blk_init);
	module_exit(nd_blk_exit);