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Commit ca0fe1df authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
Browse files

pnfs/blocklayout: refactor extent processing 



Factor out a helper for all per-extent work, and merge the now trivial
functions for lseg allocation and parsing.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 9cc47541

fs/nfs/blocklayout/blocklayout.c

+105 −102
Original line number Diff line number Diff line
@@ -513,144 +513,147 @@ static int decode_sector_number(__be32 **rp, sector_t *sp) 
	return 0;

}



/* XDR decode pnfs_block_layout4 structure */

static int

nfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,

			   struct nfs4_layoutget_res *lgr, gfp_t gfp_flags)

bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,

		struct layout_verification *lv, struct list_head *extents,

		gfp_t gfp_mask)

{

	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);

	int i, status = -EIO;

	uint32_t count;

	struct pnfs_block_extent *be = NULL, *save;

	struct xdr_stream stream;

	struct xdr_buf buf;

	struct page *scratch;

	struct pnfs_block_extent *be;

	struct nfs4_deviceid id;

	int error;

	__be32 *p;



	p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);

	if (!p)

		return -EIO;



	be = kzalloc(sizeof(*be), GFP_NOFS);

	if (!be)

		return -ENOMEM;



	memcpy(&id, p, NFS4_DEVICEID4_SIZE);

	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);



	error = -EIO;

	be->be_device = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,

						lo->plh_lc_cred, gfp_mask);

	if (!be->be_device)

		goto out_free_be;



	/*

	 * The next three values are read in as bytes, but stored in the

	 * extent structure in 512-byte granularity.

	 */

	if (decode_sector_number(&p, &be->be_f_offset) < 0)

		goto out_put_deviceid;

	if (decode_sector_number(&p, &be->be_length) < 0)

		goto out_put_deviceid;

	if (decode_sector_number(&p, &be->be_v_offset) < 0)

		goto out_put_deviceid;

	be->be_state = be32_to_cpup(p++);



	error = verify_extent(be, lv);

	if (error) {

		dprintk("%s: extent verification failed\n", __func__);

		goto out_put_deviceid;

	}



	list_add_tail(&be->be_list, extents);

	return 0;



out_put_deviceid:

	nfs4_put_deviceid_node(be->be_device);

out_free_be:

	kfree(be);

	return error;

}



static struct pnfs_layout_segment *

bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,

		gfp_t gfp_mask)

{

	struct layout_verification lv = {

		.mode = lgr->range.iomode,

		.start = lgr->range.offset >> SECTOR_SHIFT,

		.inval = lgr->range.offset >> SECTOR_SHIFT,

		.cowread = lgr->range.offset >> SECTOR_SHIFT,

	};

	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);

	struct pnfs_layout_segment *lseg;

	struct xdr_buf buf;

	struct xdr_stream xdr;

	struct page *scratch;

	int status, i;

	uint32_t count;

	__be32 *p;

	LIST_HEAD(extents);



	dprintk("---> %s\n", __func__);



	scratch = alloc_page(gfp_flags);

	lseg = kzalloc(sizeof(*lseg), gfp_mask);

	if (!lseg)

		return ERR_PTR(-ENOMEM);



	status = -ENOMEM;

	scratch = alloc_page(gfp_mask);

	if (!scratch)

		return -ENOMEM;

		goto out;



	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);

	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);

	xdr_init_decode_pages(&xdr, &buf,

			lgr->layoutp->pages, lgr->layoutp->len);

	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);



	p = xdr_inline_decode(&stream, 4);

	status = -EIO;

	p = xdr_inline_decode(&xdr, 4);

	if (unlikely(!p))

		goto out_err;

		goto out_free_scratch;



	count = be32_to_cpup(p++);

	dprintk("%s: number of extents %d\n", __func__, count);



	dprintk("%s enter, number of extents %i\n", __func__, count);

	p = xdr_inline_decode(&stream, (28 + NFS4_DEVICEID4_SIZE) * count);

	if (unlikely(!p))

		goto out_err;



	/* Decode individual extents, putting them in temporary

	 * staging area until whole layout is decoded to make error

	 * recovery easier.

	/*

	 * Decode individual extents, putting them in temporary staging area

	 * until whole layout is decoded to make error recovery easier.

	 */

	for (i = 0; i < count; i++) {

		struct nfs4_deviceid id;



		be = kzalloc(sizeof(struct pnfs_block_extent), GFP_NOFS);

		if (!be) {

			status = -ENOMEM;

			goto out_err;

		status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);

		if (status)

			goto process_extents;

	}

		memcpy(&id, p, NFS4_DEVICEID4_SIZE);

		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);



		be->be_device =

			nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,

						lo->plh_lc_cred, gfp_flags);

		if (!be->be_device)

			goto out_err;



		/* The next three values are read in as bytes,

		 * but stored as 512-byte sector lengths

		 */

		if (decode_sector_number(&p, &be->be_f_offset) < 0)

			goto out_err;

		if (decode_sector_number(&p, &be->be_length) < 0)

			goto out_err;

		if (decode_sector_number(&p, &be->be_v_offset) < 0)

			goto out_err;

		be->be_state = be32_to_cpup(p++);

		if (verify_extent(be, &lv)) {

			dprintk("%s verify failed\n", __func__);

			goto out_err;

		}

		list_add_tail(&be->be_list, &extents);

	}

	if (lgr->range.offset + lgr->range.length !=

			lv.start << SECTOR_SHIFT) {

		dprintk("%s Final length mismatch\n", __func__);

		be = NULL;

		goto out_err;

		status = -EIO;

		goto process_extents;

	}



	if (lv.start < lv.cowread) {

		dprintk("%s Final uncovered COW extent\n", __func__);

		be = NULL;

		goto out_err;

	}

	/* Extents decoded properly, now try to merge them in to

	 * existing layout extents.

	 */

	list_for_each_entry_safe(be, save, &extents, be_list) {

		list_del(&be->be_list);



		status = ext_tree_insert(bl, be);

		if (status)

			goto out_free_list;

		status = -EIO;

	}

	status = 0;

 out:

	__free_page(scratch);

	dprintk("%s returns %i\n", __func__, status);

	return status;



 out_err:

	nfs4_put_deviceid_node(be->be_device);

	kfree(be);

 out_free_list:

process_extents:

	while (!list_empty(&extents)) {

		be = list_first_entry(&extents, struct pnfs_block_extent,

		struct pnfs_block_extent *be =

			list_first_entry(&extents, struct pnfs_block_extent,

					 be_list);

		list_del(&be->be_list);



		if (!status)

			status = ext_tree_insert(bl, be);



		if (status) {

			nfs4_put_deviceid_node(be->be_device);

			kfree(be);

		}

	goto out;

	}



/* We pretty much ignore lseg, and store all data layout wide, so we

 * can correctly merge.

 */

static struct pnfs_layout_segment *bl_alloc_lseg(struct pnfs_layout_hdr *lo,

						 struct nfs4_layoutget_res *lgr,

						 gfp_t gfp_flags)

{

	struct pnfs_layout_segment *lseg;

	int status;



	dprintk("%s enter\n", __func__);

	lseg = kzalloc(sizeof(*lseg), gfp_flags);

	if (!lseg)

		return ERR_PTR(-ENOMEM);

	status = nfs4_blk_process_layoutget(lo, lgr, gfp_flags);

out_free_scratch:

	__free_page(scratch);

out:

	dprintk("%s returns %d\n", __func__, status);

	if (status) {

		/* We don't want to call the full-blown bl_free_lseg,

		 * since on error extents were not touched.

		 */

		kfree(lseg);

		return ERR_PTR(status);

	}