[mirror_ubuntu-artful-kernel.git] / fs / nfsd / blocklayout.c

/*
 * Copyright (c) 2014-2016 Christoph Hellwig.
 */
#include <linux/exportfs.h>
#include <linux/iomap.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/pr.h>

#include <linux/nfsd/debug.h>
#include <scsi/scsi_proto.h>
#include <scsi/scsi_common.h>

#include "blocklayoutxdr.h"
#include "pnfs.h"

#define NFSDDBG_FACILITY	NFSDDBG_PNFS


static __be32
nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
		struct nfsd4_layoutget *args)
{
	struct nfsd4_layout_seg *seg = &args->lg_seg;
	struct super_block *sb = inode->i_sb;
	u32 block_size = (1 << inode->i_blkbits);
	struct pnfs_block_extent *bex;
	struct iomap iomap;
	u32 device_generation = 0;
	int error;

	if (seg->offset & (block_size - 1)) {
		dprintk("pnfsd: I/O misaligned\n");
		goto out_layoutunavailable;
	}

	/*
	 * Some clients barf on non-zero block numbers for NONE or INVALID
	 * layouts, so make sure to zero the whole structure.
	 */
	error = -ENOMEM;
	bex = kzalloc(sizeof(*bex), GFP_KERNEL);
	if (!bex)
		goto out_error;
	args->lg_content = bex;

	error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
					    &iomap, seg->iomode != IOMODE_READ,
					    &device_generation);
	if (error) {
		if (error == -ENXIO)
			goto out_layoutunavailable;
		goto out_error;
	}

	if (iomap.length < args->lg_minlength) {
		dprintk("pnfsd: extent smaller than minlength\n");
		goto out_layoutunavailable;
	}

	switch (iomap.type) {
	case IOMAP_MAPPED:
		if (seg->iomode == IOMODE_READ)
			bex->es = PNFS_BLOCK_READ_DATA;
		else
			bex->es = PNFS_BLOCK_READWRITE_DATA;
		bex->soff = (iomap.blkno << 9);
		break;
	case IOMAP_UNWRITTEN:
		if (seg->iomode & IOMODE_RW) {
			/*
			 * Crack monkey special case from section 2.3.1.
			 */
			if (args->lg_minlength == 0) {
				dprintk("pnfsd: no soup for you!\n");
				goto out_layoutunavailable;
			}

			bex->es = PNFS_BLOCK_INVALID_DATA;
			bex->soff = (iomap.blkno << 9);
			break;
		}
		/*FALLTHRU*/
	case IOMAP_HOLE:
		if (seg->iomode == IOMODE_READ) {
			bex->es = PNFS_BLOCK_NONE_DATA;
			break;
		}
		/*FALLTHRU*/
	case IOMAP_DELALLOC:
	default:
		WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
		goto out_layoutunavailable;
	}

	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
	if (error)
		goto out_error;
	bex->foff = iomap.offset;
	bex->len = iomap.length;

	seg->offset = iomap.offset;
	seg->length = iomap.length;

	dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
	return 0;

out_error:
	seg->length = 0;
	return nfserrno(error);
out_layoutunavailable:
	seg->length = 0;
	return nfserr_layoutunavailable;
}

static __be32
nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
		struct iomap *iomaps, int nr_iomaps)
{
	loff_t new_size = lcp->lc_last_wr + 1;
	struct iattr iattr = { .ia_valid = 0 };
	int error;

	if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
	    timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
		lcp->lc_mtime = current_time(inode);
	iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;

	if (new_size > i_size_read(inode)) {
		iattr.ia_valid |= ATTR_SIZE;
		iattr.ia_size = new_size;
	}

	error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
			nr_iomaps, &iattr);
	kfree(iomaps);
	return nfserrno(error);
}

#ifdef CONFIG_NFSD_BLOCKLAYOUT
static int
nfsd4_block_get_device_info_simple(struct super_block *sb,
		struct nfsd4_getdeviceinfo *gdp)
{
	struct pnfs_block_deviceaddr *dev;
	struct pnfs_block_volume *b;

	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
		      sizeof(struct pnfs_block_volume), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;
	gdp->gd_device = dev;

	dev->nr_volumes = 1;
	b = &dev->volumes[0];

	b->type = PNFS_BLOCK_VOLUME_SIMPLE;
	b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
	return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
			&b->simple.offset);
}

static __be32
nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
		struct svc_rqst *rqstp,
		struct nfs4_client *clp,
		struct nfsd4_getdeviceinfo *gdp)
{
	if (sb->s_bdev != sb->s_bdev->bd_contains)
		return nfserr_inval;
	return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
}

static __be32
nfsd4_block_proc_layoutcommit(struct inode *inode,
		struct nfsd4_layoutcommit *lcp)
{
	struct iomap *iomaps;
	int nr_iomaps;

	nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
			lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
	if (nr_iomaps < 0)
		return nfserrno(nr_iomaps);

	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
}

const struct nfsd4_layout_ops bl_layout_ops = {
	/*
	 * Pretend that we send notification to the client.  This is a blatant
	 * lie to force recent Linux clients to cache our device IDs.
	 * We rarely ever change the device ID, so the harm of leaking deviceids
	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
	 * in this regard, but I filed errata 4119 for this a while ago, and
	 * hopefully the Linux client will eventually start caching deviceids
	 * without this again.
	 */
	.notify_types		=
			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
	.proc_getdeviceinfo	= nfsd4_block_proc_getdeviceinfo,
	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
	.proc_layoutget		= nfsd4_block_proc_layoutget,
	.encode_layoutget	= nfsd4_block_encode_layoutget,
	.proc_layoutcommit	= nfsd4_block_proc_layoutcommit,
};
#endif /* CONFIG_NFSD_BLOCKLAYOUT */

#ifdef CONFIG_NFSD_SCSILAYOUT
static int nfsd4_scsi_identify_device(struct block_device *bdev,
		struct pnfs_block_volume *b)
{
	struct request_queue *q = bdev->bd_disk->queue;
	struct request *rq;
	size_t bufflen = 252, len, id_len;
	u8 *buf, *d, type, assoc;
	int error;

	buf = kzalloc(bufflen, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	rq = blk_get_request(q, READ, GFP_KERNEL);
	if (IS_ERR(rq)) {
		error = -ENOMEM;
		goto out_free_buf;
	}
	blk_rq_set_block_pc(rq);

	error = blk_rq_map_kern(q, rq, buf, bufflen, GFP_KERNEL);
	if (error)
		goto out_put_request;

	rq->cmd[0] = INQUIRY;
	rq->cmd[1] = 1;
	rq->cmd[2] = 0x83;
	rq->cmd[3] = bufflen >> 8;
	rq->cmd[4] = bufflen & 0xff;
	rq->cmd_len = COMMAND_SIZE(INQUIRY);

	error = blk_execute_rq(rq->q, NULL, rq, 1);
	if (error) {
		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
			rq->errors);
		goto out_put_request;
	}

	len = (buf[2] << 8) + buf[3] + 4;
	if (len > bufflen) {
		pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
			len);
		goto out_put_request;
	}

	d = buf + 4;
	for (d = buf + 4; d < buf + len; d += id_len + 4) {
		id_len = d[3];
		type = d[1] & 0xf;
		assoc = (d[1] >> 4) & 0x3;

		/*
		 * We only care about a EUI-64 and NAA designator types
		 * with LU association.
		 */
		if (assoc != 0x00)
			continue;
		if (type != 0x02 && type != 0x03)
			continue;
		if (id_len != 8 && id_len != 12 && id_len != 16)
			continue;

		b->scsi.code_set = PS_CODE_SET_BINARY;
		b->scsi.designator_type = type == 0x02 ?
			PS_DESIGNATOR_EUI64 : PS_DESIGNATOR_NAA;
		b->scsi.designator_len = id_len;
		memcpy(b->scsi.designator, d + 4, id_len);

		/*
		 * If we found a 8 or 12 byte descriptor continue on to
		 * see if a 16 byte one is available.  If we find a
		 * 16 byte descriptor we're done.
		 */
		if (id_len == 16)
			break;
	}

out_put_request:
	blk_put_request(rq);
out_free_buf:
	kfree(buf);
	return error;
}

#define NFSD_MDS_PR_KEY		0x0100000000000000ULL

/*
 * We use the client ID as a unique key for the reservations.
 * This allows us to easily fence a client when recalls fail.
 */
static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
{
	return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id;
}

static int
nfsd4_block_get_device_info_scsi(struct super_block *sb,
		struct nfs4_client *clp,
		struct nfsd4_getdeviceinfo *gdp)
{
	struct pnfs_block_deviceaddr *dev;
	struct pnfs_block_volume *b;
	const struct pr_ops *ops;
	int error;

	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
		      sizeof(struct pnfs_block_volume), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;
	gdp->gd_device = dev;

	dev->nr_volumes = 1;
	b = &dev->volumes[0];

	b->type = PNFS_BLOCK_VOLUME_SCSI;
	b->scsi.pr_key = nfsd4_scsi_pr_key(clp);

	error = nfsd4_scsi_identify_device(sb->s_bdev, b);
	if (error)
		return error;

	ops = sb->s_bdev->bd_disk->fops->pr_ops;
	if (!ops) {
		pr_err("pNFS: device %s does not support PRs.\n",
			sb->s_id);
		return -EINVAL;
	}

	error = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
	if (error) {
		pr_err("pNFS: failed to register key for device %s.\n",
			sb->s_id);
		return -EINVAL;
	}

	error = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
			PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
	if (error) {
		pr_err("pNFS: failed to reserve device %s.\n",
			sb->s_id);
		return -EINVAL;
	}

	return 0;
}

static __be32
nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
		struct svc_rqst *rqstp,
		struct nfs4_client *clp,
		struct nfsd4_getdeviceinfo *gdp)
{
	if (sb->s_bdev != sb->s_bdev->bd_contains)
		return nfserr_inval;
	return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
}
static __be32
nfsd4_scsi_proc_layoutcommit(struct inode *inode,
		struct nfsd4_layoutcommit *lcp)
{
	struct iomap *iomaps;
	int nr_iomaps;

	nr_iomaps = nfsd4_scsi_decode_layoutupdate(lcp->lc_up_layout,
			lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
	if (nr_iomaps < 0)
		return nfserrno(nr_iomaps);

	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
}

static void
nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
{
	struct nfs4_client *clp = ls->ls_stid.sc_client;
	struct block_device *bdev = ls->ls_file->f_path.mnt->mnt_sb->s_bdev;

	bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
			nfsd4_scsi_pr_key(clp), 0, true);
}

const struct nfsd4_layout_ops scsi_layout_ops = {
	/*
	 * Pretend that we send notification to the client.  This is a blatant
	 * lie to force recent Linux clients to cache our device IDs.
	 * We rarely ever change the device ID, so the harm of leaking deviceids
	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
	 * in this regard, but I filed errata 4119 for this a while ago, and
	 * hopefully the Linux client will eventually start caching deviceids
	 * without this again.
	 */
	.notify_types		=
			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
	.proc_getdeviceinfo	= nfsd4_scsi_proc_getdeviceinfo,
	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
	.proc_layoutget		= nfsd4_block_proc_layoutget,
	.encode_layoutget	= nfsd4_block_encode_layoutget,
	.proc_layoutcommit	= nfsd4_scsi_proc_layoutcommit,
	.fence_client		= nfsd4_scsi_fence_client,
};
#endif /* CONFIG_NFSD_SCSILAYOUT */
Commit	Line	Data
8650b8a0	1	/*
f99d4fbd	2	* Copyright (c) 2014-2016 Christoph Hellwig.
8650b8a0 CH	3	*/
8650b8a0 CH	4	#include <linux/exportfs.h>
199a31c6	5	#include <linux/iomap.h>
8650b8a0 CH	6	#include <linux/genhd.h>
8650b8a0 CH	7	#include <linux/slab.h>
f99d4fbd	8	#include <linux/pr.h>
8650b8a0 CH	9
8650b8a0 CH	10	#include <linux/nfsd/debug.h>
f99d4fbd CH	11	#include <scsi/scsi_proto.h>
f99d4fbd CH	12	#include <scsi/scsi_common.h>
8650b8a0 CH	13
	14	#include "blocklayoutxdr.h"
	15	#include "pnfs.h"
	16
	17	#define NFSDDBG_FACILITY NFSDDBG_PNFS
	18
	19
8650b8a0 CH	20	static __be32
	21	nfsd4_block_proc_layoutget(struct inode inode, const struct svc_fh fhp,
	22	struct nfsd4_layoutget *args)
	23	{
	24	struct nfsd4_layout_seg *seg = &args->lg_seg;
	25	struct super_block *sb = inode->i_sb;
	26	u32 block_size = (1 << inode->i_blkbits);
	27	struct pnfs_block_extent *bex;
	28	struct iomap iomap;
	29	u32 device_generation = 0;
	30	int error;
	31
8650b8a0 CH	32	if (seg->offset & (block_size - 1)) {
	33	dprintk("pnfsd: I/O misaligned\n");
	34	goto out_layoutunavailable;
	35	}
	36
	37	/*
	38	* Some clients barf on non-zero block numbers for NONE or INVALID
	39	* layouts, so make sure to zero the whole structure.
	40	*/
	41	error = -ENOMEM;
	42	bex = kzalloc(sizeof(*bex), GFP_KERNEL);
	43	if (!bex)
	44	goto out_error;
	45	args->lg_content = bex;
	46
	47	error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
	48	&iomap, seg->iomode != IOMODE_READ,
	49	&device_generation);
	50	if (error) {
	51	if (error == -ENXIO)
	52	goto out_layoutunavailable;
	53	goto out_error;
	54	}
	55
	56	if (iomap.length < args->lg_minlength) {
	57	dprintk("pnfsd: extent smaller than minlength\n");
	58	goto out_layoutunavailable;
	59	}
	60
	61	switch (iomap.type) {
	62	case IOMAP_MAPPED:
	63	if (seg->iomode == IOMODE_READ)
	64	bex->es = PNFS_BLOCK_READ_DATA;
	65	else
	66	bex->es = PNFS_BLOCK_READWRITE_DATA;
	67	bex->soff = (iomap.blkno << 9);
	68	break;
	69	case IOMAP_UNWRITTEN:
	70	if (seg->iomode & IOMODE_RW) {
	71	/*
	72	* Crack monkey special case from section 2.3.1.
	73	*/
	74	if (args->lg_minlength == 0) {
	75	dprintk("pnfsd: no soup for you!\n");
	76	goto out_layoutunavailable;
	77	}
	78
	79	bex->es = PNFS_BLOCK_INVALID_DATA;
	80	bex->soff = (iomap.blkno << 9);
	81	break;
	82	}
	83	/FALLTHRU/
	84	case IOMAP_HOLE:
	85	if (seg->iomode == IOMODE_READ) {
	86	bex->es = PNFS_BLOCK_NONE_DATA;
	87	break;
	88	}
	89	/FALLTHRU/
	90	case IOMAP_DELALLOC:
	91	default:
	92	WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
	93	goto out_layoutunavailable;
	94	}
	95
96	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
97	if (error)
98	goto out_error;
99	bex->foff = iomap.offset;
100	bex->len = iomap.length;
101
102	seg->offset = iomap.offset;
103	seg->length = iomap.length;
104
85369523	105	dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
8650b8a0 CH	106	return 0;
	107
	108	out_error:
	109	seg->length = 0;
	110	return nfserrno(error);
	111	out_layoutunavailable:
	112	seg->length = 0;
	113	return nfserr_layoutunavailable;
	114	}
	115
	116	static __be32
368248ee CH	117	nfsd4_block_commit_blocks(struct inode inode, struct nfsd4_layoutcommit lcp,
368248ee CH	118	struct iomap *iomaps, int nr_iomaps)
8650b8a0 CH	119	{
	120	loff_t new_size = lcp->lc_last_wr + 1;
	121	struct iattr iattr = { .ia_valid = 0 };
8650b8a0 CH	122	int error;
8650b8a0 CH	123
8650b8a0 CH	124	if (lcp->lc_mtime.tv_nsec == UTIME_NOW \|\|
8650b8a0 CH	125	timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
c2050a45	126	lcp->lc_mtime = current_time(inode);
8650b8a0 CH	127	iattr.ia_valid \|= ATTR_ATIME \| ATTR_CTIME \| ATTR_MTIME;
	128	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
	129
	130	if (new_size > i_size_read(inode)) {
	131	iattr.ia_valid \|= ATTR_SIZE;
	132	iattr.ia_size = new_size;
	133	}
	134
	135	error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
	136	nr_iomaps, &iattr);
	137	kfree(iomaps);
	138	return nfserrno(error);
	139	}
	140
368248ee CH	141	#ifdef CONFIG_NFSD_BLOCKLAYOUT
	142	static int
	143	nfsd4_block_get_device_info_simple(struct super_block *sb,
	144	struct nfsd4_getdeviceinfo *gdp)
	145	{
	146	struct pnfs_block_deviceaddr *dev;
	147	struct pnfs_block_volume *b;
	148
	149	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
	150	sizeof(struct pnfs_block_volume), GFP_KERNEL);
	151	if (!dev)
	152	return -ENOMEM;
	153	gdp->gd_device = dev;
	154
	155	dev->nr_volumes = 1;
	156	b = &dev->volumes[0];
	157
	158	b->type = PNFS_BLOCK_VOLUME_SIMPLE;
	159	b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
	160	return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
	161	&b->simple.offset);
	162	}
	163
	164	static __be32
	165	nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
d7c920d1	166	struct svc_rqst *rqstp,
f99d4fbd	167	struct nfs4_client *clp,
368248ee CH	168	struct nfsd4_getdeviceinfo *gdp)
	169	{
	170	if (sb->s_bdev != sb->s_bdev->bd_contains)
	171	return nfserr_inval;
	172	return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
	173	}
	174
	175	static __be32
	176	nfsd4_block_proc_layoutcommit(struct inode *inode,
	177	struct nfsd4_layoutcommit *lcp)
	178	{
	179	struct iomap *iomaps;
	180	int nr_iomaps;
	181
	182	nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
	183	lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
	184	if (nr_iomaps < 0)
	185	return nfserrno(nr_iomaps);
	186
	187	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
	188	}
	189
8650b8a0	190	const struct nfsd4_layout_ops bl_layout_ops = {
40cdc7a5 CH	191	/*
	192	* Pretend that we send notification to the client. This is a blatant
	193	* lie to force recent Linux clients to cache our device IDs.
	194	* We rarely ever change the device ID, so the harm of leaking deviceids
	195	* for a while isn't too bad. Unfortunately RFC5661 is a complete mess
	196	* in this regard, but I filed errata 4119 for this a while ago, and
	197	* hopefully the Linux client will eventually start caching deviceids
	198	* without this again.
	199	*/
	200	.notify_types =
	201	NOTIFY_DEVICEID4_DELETE \| NOTIFY_DEVICEID4_CHANGE,
8650b8a0 CH	202	.proc_getdeviceinfo = nfsd4_block_proc_getdeviceinfo,
	203	.encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo,
	204	.proc_layoutget = nfsd4_block_proc_layoutget,
	205	.encode_layoutget = nfsd4_block_encode_layoutget,
	206	.proc_layoutcommit = nfsd4_block_proc_layoutcommit,
	207	};
368248ee	208	#endif /* CONFIG_NFSD_BLOCKLAYOUT */
f99d4fbd CH	209
	210	#ifdef CONFIG_NFSD_SCSILAYOUT
	211	static int nfsd4_scsi_identify_device(struct block_device *bdev,
	212	struct pnfs_block_volume *b)
	213	{
	214	struct request_queue *q = bdev->bd_disk->queue;
	215	struct request *rq;
	216	size_t bufflen = 252, len, id_len;
	217	u8 buf, d, type, assoc;
	218	int error;
	219
	220	buf = kzalloc(bufflen, GFP_KERNEL);
	221	if (!buf)
	222	return -ENOMEM;
	223
	224	rq = blk_get_request(q, READ, GFP_KERNEL);
	225	if (IS_ERR(rq)) {
	226	error = -ENOMEM;
	227	goto out_free_buf;
	228	}
	229	blk_rq_set_block_pc(rq);
	230
	231	error = blk_rq_map_kern(q, rq, buf, bufflen, GFP_KERNEL);
	232	if (error)
	233	goto out_put_request;
	234
	235	rq->cmd[0] = INQUIRY;
	236	rq->cmd[1] = 1;
	237	rq->cmd[2] = 0x83;
	238	rq->cmd[3] = bufflen >> 8;
	239	rq->cmd[4] = bufflen & 0xff;
	240	rq->cmd_len = COMMAND_SIZE(INQUIRY);
	241
	242	error = blk_execute_rq(rq->q, NULL, rq, 1);
	243	if (error) {
	244	pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
	245	rq->errors);
	246	goto out_put_request;
	247	}
	248
	249	len = (buf[2] << 8) + buf[3] + 4;
	250	if (len > bufflen) {
	251	pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
	252	len);
	253	goto out_put_request;
	254	}
	255
	256	d = buf + 4;
	257	for (d = buf + 4; d < buf + len; d += id_len + 4) {
	258	id_len = d[3];
	259	type = d[1] & 0xf;
	260	assoc = (d[1] >> 4) & 0x3;
	261
	262	/*
	263	* We only care about a EUI-64 and NAA designator types
	264	* with LU association.
	265	*/
	266	if (assoc != 0x00)
	267	continue;
	268	if (type != 0x02 && type != 0x03)
	269	continue;
	270	if (id_len != 8 && id_len != 12 && id_len != 16)
	271	continue;
	272
273	b->scsi.code_set = PS_CODE_SET_BINARY;
274	b->scsi.designator_type = type == 0x02 ?
275	PS_DESIGNATOR_EUI64 : PS_DESIGNATOR_NAA;
276	b->scsi.designator_len = id_len;
277	memcpy(b->scsi.designator, d + 4, id_len);
278
279	/*
280	* If we found a 8 or 12 byte descriptor continue on to
281	* see if a 16 byte one is available. If we find a
282	* 16 byte descriptor we're done.
283	*/
284	if (id_len == 16)
285	break;
286	}
287
288	out_put_request:
289	blk_put_request(rq);
290	out_free_buf:
291	kfree(buf);
292	return error;
293	}
294
eee93016	295	#define NFSD_MDS_PR_KEY 0x0100000000000000ULL
f99d4fbd CH	296
	297	/*
	298	* We use the client ID as a unique key for the reservations.
	299	* This allows us to easily fence a client when recalls fail.
	300	*/
	301	static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
	302	{
	303	return ((u64)clp->cl_clientid.cl_boot << 32) \| clp->cl_clientid.cl_id;
	304	}
	305
	306	static int
	307	nfsd4_block_get_device_info_scsi(struct super_block *sb,
	308	struct nfs4_client *clp,
	309	struct nfsd4_getdeviceinfo *gdp)
	310	{
	311	struct pnfs_block_deviceaddr *dev;
	312	struct pnfs_block_volume *b;
	313	const struct pr_ops *ops;
	314	int error;
	315
	316	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
	317	sizeof(struct pnfs_block_volume), GFP_KERNEL);
	318	if (!dev)
	319	return -ENOMEM;
	320	gdp->gd_device = dev;
	321
	322	dev->nr_volumes = 1;
	323	b = &dev->volumes[0];
	324
	325	b->type = PNFS_BLOCK_VOLUME_SCSI;
	326	b->scsi.pr_key = nfsd4_scsi_pr_key(clp);
	327
	328	error = nfsd4_scsi_identify_device(sb->s_bdev, b);
	329	if (error)
	330	return error;
	331
	332	ops = sb->s_bdev->bd_disk->fops->pr_ops;
	333	if (!ops) {
	334	pr_err("pNFS: device %s does not support PRs.\n",
	335	sb->s_id);
	336	return -EINVAL;
	337	}
	338
	339	error = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
	340	if (error) {
	341	pr_err("pNFS: failed to register key for device %s.\n",
	342	sb->s_id);
	343	return -EINVAL;
	344	}
	345
	346	error = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
	347	PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
	348	if (error) {
	349	pr_err("pNFS: failed to reserve device %s.\n",
	350	sb->s_id);
	351	return -EINVAL;
	352	}
	353
	354	return 0;
	355	}
	356
	357	static __be32
	358	nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
d7c920d1	359	struct svc_rqst *rqstp,
f99d4fbd CH	360	struct nfs4_client *clp,
	361	struct nfsd4_getdeviceinfo *gdp)
	362	{
	363	if (sb->s_bdev != sb->s_bdev->bd_contains)
	364	return nfserr_inval;
	365	return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
	366	}
	367	static __be32
	368	nfsd4_scsi_proc_layoutcommit(struct inode *inode,
	369	struct nfsd4_layoutcommit *lcp)
	370	{
	371	struct iomap *iomaps;
	372	int nr_iomaps;
	373
	374	nr_iomaps = nfsd4_scsi_decode_layoutupdate(lcp->lc_up_layout,
	375	lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
	376	if (nr_iomaps < 0)
	377	return nfserrno(nr_iomaps);
	378
	379	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
	380	}
	381
	382	static void
	383	nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
	384	{
	385	struct nfs4_client *clp = ls->ls_stid.sc_client;
	386	struct block_device *bdev = ls->ls_file->f_path.mnt->mnt_sb->s_bdev;
	387
	388	bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
	389	nfsd4_scsi_pr_key(clp), 0, true);
	390	}
	391
	392	const struct nfsd4_layout_ops scsi_layout_ops = {
	393	/*
	394	* Pretend that we send notification to the client. This is a blatant
	395	* lie to force recent Linux clients to cache our device IDs.
	396	* We rarely ever change the device ID, so the harm of leaking deviceids
	397	* for a while isn't too bad. Unfortunately RFC5661 is a complete mess
	398	* in this regard, but I filed errata 4119 for this a while ago, and
	399	* hopefully the Linux client will eventually start caching deviceids
	400	* without this again.
	401	*/
	402	.notify_types =
	403	NOTIFY_DEVICEID4_DELETE \| NOTIFY_DEVICEID4_CHANGE,
	404	.proc_getdeviceinfo = nfsd4_scsi_proc_getdeviceinfo,
	405	.encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo,
	406	.proc_layoutget = nfsd4_block_proc_layoutget,
	407	.encode_layoutget = nfsd4_block_encode_layoutget,
	408	.proc_layoutcommit = nfsd4_scsi_proc_layoutcommit,
	409	.fence_client = nfsd4_scsi_fence_client,
	410	};
	411	#endif /* CONFIG_NFSD_SCSILAYOUT */