/*

   * Copyright (c) 2014-2016 Christoph Hellwig.

   */
  #include <linux/sunrpc/svc.h>
  #include <linux/exportfs.h>

  #include <linux/iomap.h>

  #include <linux/nfs4.h>
  
  #include "nfsd.h"
  #include "blocklayoutxdr.h"
  
  #define NFSDDBG_FACILITY	NFSDDBG_PNFS
  
  
  __be32
  nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
  		struct nfsd4_layoutget *lgp)
  {
  	struct pnfs_block_extent *b = lgp->lg_content;
  	int len = sizeof(__be32) + 5 * sizeof(__be64) + sizeof(__be32);
  	__be32 *p;
  
  	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
  	if (!p)
  		return nfserr_toosmall;
  
  	*p++ = cpu_to_be32(len);
  	*p++ = cpu_to_be32(1);		/* we always return a single extent */
  
  	p = xdr_encode_opaque_fixed(p, &b->vol_id,
  			sizeof(struct nfsd4_deviceid));
  	p = xdr_encode_hyper(p, b->foff);
  	p = xdr_encode_hyper(p, b->len);
  	p = xdr_encode_hyper(p, b->soff);
  	*p++ = cpu_to_be32(b->es);
  	return 0;
  }
  
  static int
  nfsd4_block_encode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
  {
  	__be32 *p;
  	int len;
  
  	switch (b->type) {
  	case PNFS_BLOCK_VOLUME_SIMPLE:

  		len = 4 + 4 + 8 + 4 + (XDR_QUADLEN(b->simple.sig_len) << 2);

  		p = xdr_reserve_space(xdr, len);
  		if (!p)
  			return -ETOOSMALL;
  
  		*p++ = cpu_to_be32(b->type);
  		*p++ = cpu_to_be32(1);	/* single signature */
  		p = xdr_encode_hyper(p, b->simple.offset);
  		p = xdr_encode_opaque(p, b->simple.sig, b->simple.sig_len);
  		break;

  	case PNFS_BLOCK_VOLUME_SCSI:

  		len = 4 + 4 + 4 + 4 + (XDR_QUADLEN(b->scsi.designator_len) << 2) + 8;

  		p = xdr_reserve_space(xdr, len);
  		if (!p)
  			return -ETOOSMALL;
  
  		*p++ = cpu_to_be32(b->type);
  		*p++ = cpu_to_be32(b->scsi.code_set);
  		*p++ = cpu_to_be32(b->scsi.designator_type);
  		p = xdr_encode_opaque(p, b->scsi.designator, b->scsi.designator_len);
  		p = xdr_encode_hyper(p, b->scsi.pr_key);
  		break;

  	default:
  		return -ENOTSUPP;
  	}
  
  	return len;
  }
  
  __be32
  nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
  		struct nfsd4_getdeviceinfo *gdp)
  {
  	struct pnfs_block_deviceaddr *dev = gdp->gd_device;
  	int len = sizeof(__be32), ret, i;
  	__be32 *p;
  
  	p = xdr_reserve_space(xdr, len + sizeof(__be32));
  	if (!p)
  		return nfserr_resource;
  
  	for (i = 0; i < dev->nr_volumes; i++) {
  		ret = nfsd4_block_encode_volume(xdr, &dev->volumes[i]);
  		if (ret < 0)
  			return nfserrno(ret);
  		len += ret;
  	}
  
  	/*
  	 * Fill in the overall length and number of volumes at the beginning
  	 * of the layout.
  	 */
  	*p++ = cpu_to_be32(len);
  	*p++ = cpu_to_be32(dev->nr_volumes);
  	return 0;
  }
  
  int
  nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
  		u32 block_size)
  {
  	struct iomap *iomaps;

  	u32 nr_iomaps, i;

  
  	if (len < sizeof(u32)) {
  		dprintk("%s: extent array too small: %u
  ", __func__, len);
  		return -EINVAL;
  	}

  	len -= sizeof(u32);
  	if (len % PNFS_BLOCK_EXTENT_SIZE) {
  		dprintk("%s: extent array invalid: %u
  ", __func__, len);
  		return -EINVAL;
  	}

  
  	nr_iomaps = be32_to_cpup(p++);

  	if (nr_iomaps != len / PNFS_BLOCK_EXTENT_SIZE) {

  		dprintk("%s: extent array size mismatch: %u/%u
  ",

  			__func__, len, nr_iomaps);

  		return -EINVAL;
  	}
  
  	iomaps = kcalloc(nr_iomaps, sizeof(*iomaps), GFP_KERNEL);
  	if (!iomaps) {
  		dprintk("%s: failed to allocate extent array
  ", __func__);
  		return -ENOMEM;
  	}
  
  	for (i = 0; i < nr_iomaps; i++) {
  		struct pnfs_block_extent bex;
  
  		memcpy(&bex.vol_id, p, sizeof(struct nfsd4_deviceid));
  		p += XDR_QUADLEN(sizeof(struct nfsd4_deviceid));
  
  		p = xdr_decode_hyper(p, &bex.foff);
  		if (bex.foff & (block_size - 1)) {

  			dprintk("%s: unaligned offset 0x%llx
  ",

  				__func__, bex.foff);
  			goto fail;
  		}
  		p = xdr_decode_hyper(p, &bex.len);
  		if (bex.len & (block_size - 1)) {

  			dprintk("%s: unaligned length 0x%llx
  ",

  				__func__, bex.foff);
  			goto fail;
  		}
  		p = xdr_decode_hyper(p, &bex.soff);
  		if (bex.soff & (block_size - 1)) {

  			dprintk("%s: unaligned disk offset 0x%llx
  ",

  				__func__, bex.soff);
  			goto fail;
  		}
  		bex.es = be32_to_cpup(p++);
  		if (bex.es != PNFS_BLOCK_READWRITE_DATA) {
  			dprintk("%s: incorrect extent state %d
  ",
  				__func__, bex.es);
  			goto fail;
  		}
  
  		iomaps[i].offset = bex.foff;
  		iomaps[i].length = bex.len;
  	}
  
  	*iomapp = iomaps;
  	return nr_iomaps;
  fail:
  	kfree(iomaps);
  	return -EINVAL;
  }

  
  int
  nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
  		u32 block_size)
  {
  	struct iomap *iomaps;
  	u32 nr_iomaps, expected, i;
  
  	if (len < sizeof(u32)) {
  		dprintk("%s: extent array too small: %u
  ", __func__, len);
  		return -EINVAL;
  	}
  
  	nr_iomaps = be32_to_cpup(p++);
  	expected = sizeof(__be32) + nr_iomaps * PNFS_SCSI_RANGE_SIZE;
  	if (len != expected) {
  		dprintk("%s: extent array size mismatch: %u/%u
  ",
  			__func__, len, expected);
  		return -EINVAL;
  	}
  
  	iomaps = kcalloc(nr_iomaps, sizeof(*iomaps), GFP_KERNEL);
  	if (!iomaps) {
  		dprintk("%s: failed to allocate extent array
  ", __func__);
  		return -ENOMEM;
  	}
  
  	for (i = 0; i < nr_iomaps; i++) {
  		u64 val;
  
  		p = xdr_decode_hyper(p, &val);
  		if (val & (block_size - 1)) {
  			dprintk("%s: unaligned offset 0x%llx
  ", __func__, val);
  			goto fail;
  		}
  		iomaps[i].offset = val;
  
  		p = xdr_decode_hyper(p, &val);
  		if (val & (block_size - 1)) {
  			dprintk("%s: unaligned length 0x%llx
  ", __func__, val);
  			goto fail;
  		}
  		iomaps[i].length = val;
  	}
  
  	*iomapp = iomaps;
  	return nr_iomaps;
  fail:
  	kfree(iomaps);
  	return -EINVAL;
  }