1 files changed, 427 insertions, 959 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index cbb1797149d5..5228f201d3d5 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -35,7 +35,6 @@
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/bio.h>		/* struct bio */
-#include <linux/buffer_head.h>	/* various write calls */
 #include <linux/prefetch.h>
 #include <linux/pagevec.h>
 
@@ -50,40 +49,16 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
 
-static void print_page(struct page *page)
+static bool is_hole(struct pnfs_block_extent *be)
 {
-	dprintk("PRINTPAGE page %p\n", page);
-	dprintk("	PagePrivate %d\n", PagePrivate(page));
-	dprintk("	PageUptodate %d\n", PageUptodate(page));
-	dprintk("	PageError %d\n", PageError(page));
-	dprintk("	PageDirty %d\n", PageDirty(page));
-	dprintk("	PageReferenced %d\n", PageReferenced(page));
-	dprintk("	PageLocked %d\n", PageLocked(page));
-	dprintk("	PageWriteback %d\n", PageWriteback(page));
-	dprintk("	PageMappedToDisk %d\n", PageMappedToDisk(page));
-	dprintk("\n");
-}
-
-/* Given the be associated with isect, determine if page data needs to be
- * initialized.
- */
-static int is_hole(struct pnfs_block_extent *be, sector_t isect)
-{
-	if (be->be_state == PNFS_BLOCK_NONE_DATA)
-		return 1;
-	else if (be->be_state != PNFS_BLOCK_INVALID_DATA)
-		return 0;
-	else
-		return !bl_is_sector_init(be->be_inval, isect);
-}
-
-/* Given the be associated with isect, determine if page data can be
- * written to disk.
- */
-static int is_writable(struct pnfs_block_extent *be, sector_t isect)
-{
-	return (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
-		be->be_state == PNFS_BLOCK_INVALID_DATA);
+	switch (be->be_state) {
+	case PNFS_BLOCK_NONE_DATA:
+		return true;
+	case PNFS_BLOCK_INVALID_DATA:
+		return be->be_tag ? false : true;
+	default:
+		return false;
+	}
 }
 
 /* The data we are handed might be spread across several bios.  We need
@@ -91,9 +66,8 @@ static int is_writable(struct pnfs_block_extent *be, sector_t isect)
  */
 struct parallel_io {
 	struct kref refcnt;
-	void (*pnfs_callback) (void *data, int num_se);
+	void (*pnfs_callback) (void *data);
 	void *data;
-	int bse_count;
 };
 
 static inline struct parallel_io *alloc_parallel(void *data)
@@ -104,7 +78,6 @@ static inline struct parallel_io *alloc_parallel(void *data)
 	if (rv) {
 		rv->data = data;
 		kref_init(&rv->refcnt);
-		rv->bse_count = 0;
 	}
 	return rv;
 }
@@ -119,7 +92,7 @@ static void destroy_parallel(struct kref *kref)
 	struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
 
 	dprintk("%s enter\n", __func__);
-	p->pnfs_callback(p->data, p->bse_count);
+	p->pnfs_callback(p->data);
 	kfree(p);
 }
 
@@ -141,10 +114,9 @@ bl_submit_bio(int rw, struct bio *bio)
 	return NULL;
 }
 
-static struct bio *bl_alloc_init_bio(int npg, sector_t isect,
-				     struct pnfs_block_extent *be,
-				     void (*end_io)(struct bio *, int err),
-				     struct parallel_io *par)
+static struct bio *
+bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector,
+		void (*end_io)(struct bio *, int err), struct parallel_io *par)
 {
 	struct bio *bio;
 
@@ -156,58 +128,64 @@ static struct bio *bl_alloc_init_bio(int npg, sector_t isect,
 	}
 
 	if (bio) {
-		bio->bi_iter.bi_sector = isect - be->be_f_offset +
-			be->be_v_offset;
-		bio->bi_bdev = be->be_mdev;
+		bio->bi_iter.bi_sector = disk_sector;
+		bio->bi_bdev = bdev;
 		bio->bi_end_io = end_io;
 		bio->bi_private = par;
 	}
 	return bio;
 }
 
-static struct bio *do_add_page_to_bio(struct bio *bio, int npg, int rw,
-				      sector_t isect, struct page *page,
-				      struct pnfs_block_extent *be,
-				      void (*end_io)(struct bio *, int err),
-				      struct parallel_io *par,
-				      unsigned int offset, int len)
+static struct bio *
+do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect,
+		struct page *page, struct pnfs_block_dev_map *map,
+		struct pnfs_block_extent *be,
+		void (*end_io)(struct bio *, int err),
+		struct parallel_io *par, unsigned int offset, int *len)
 {
-	isect = isect + (offset >> SECTOR_SHIFT);
+	struct pnfs_block_dev *dev =
+		container_of(be->be_device, struct pnfs_block_dev, node);
+	u64 disk_addr, end;
+
 	dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
-		npg, rw, (unsigned long long)isect, offset, len);
+		npg, rw, (unsigned long long)isect, offset, *len);
+
+	/* translate to device offset */
+	isect += be->be_v_offset;
+	isect -= be->be_f_offset;
+
+	/* translate to physical disk offset */
+	disk_addr = (u64)isect << SECTOR_SHIFT;
+	if (disk_addr < map->start || disk_addr >= map->start + map->len) {
+		if (!dev->map(dev, disk_addr, map))
+			return ERR_PTR(-EIO);
+		bio = bl_submit_bio(rw, bio);
+	}
+	disk_addr += map->disk_offset;
+	disk_addr -= map->start;
+
+	/* limit length to what the device mapping allows */
+	end = disk_addr + *len;
+	if (end >= map->start + map->len)
+		*len = map->start + map->len - disk_addr;
+
 retry:
 	if (!bio) {
-		bio = bl_alloc_init_bio(npg, isect, be, end_io, par);
+		bio = bl_alloc_init_bio(npg, map->bdev,
+				disk_addr >> SECTOR_SHIFT, end_io, par);
 		if (!bio)
 			return ERR_PTR(-ENOMEM);
 	}
-	if (bio_add_page(bio, page, len, offset) < len) {
+	if (bio_add_page(bio, page, *len, offset) < *len) {
 		bio = bl_submit_bio(rw, bio);
 		goto retry;
 	}
 	return bio;
 }
 
-static struct bio *bl_add_page_to_bio(struct bio *bio, int npg, int rw,
-				      sector_t isect, struct page *page,
-				      struct pnfs_block_extent *be,
-				      void (*end_io)(struct bio *, int err),
-				      struct parallel_io *par)
-{
-	return do_add_page_to_bio(bio, npg, rw, isect, page, be,
-				  end_io, par, 0, PAGE_CACHE_SIZE);
-}
-
-/* This is basically copied from mpage_end_io_read */
 static void bl_end_io_read(struct bio *bio, int err)
 {
 	struct parallel_io *par = bio->bi_private;
-	struct bio_vec *bvec;
-	int i;
-
-	if (!err)
-		bio_for_each_segment_all(bvec, bio, i)
-			SetPageUptodate(bvec->bv_page);
 
 	if (err) {
 		struct nfs_pgio_header *header = par->data;
@@ -216,6 +194,7 @@ static void bl_end_io_read(struct bio *bio, int err)
 			header->pnfs_error = -EIO;
 		pnfs_set_lo_fail(header->lseg);
 	}
+
 	bio_put(bio);
 	put_parallel(par);
 }
@@ -231,7 +210,7 @@ static void bl_read_cleanup(struct work_struct *work)
 }
 
 static void
-bl_end_par_io_read(void *data, int unused)
+bl_end_par_io_read(void *data)
 {
 	struct nfs_pgio_header *hdr = data;
 
@@ -241,88 +220,78 @@ bl_end_par_io_read(void *data, int unused)
 }
 
 static enum pnfs_try_status
-bl_read_pagelist(struct nfs_pgio_header *hdr)
+bl_read_pagelist(struct nfs_pgio_header *header)
 {
-	struct nfs_pgio_header *header = hdr;
-	int i, hole;
+	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
+	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
 	struct bio *bio = NULL;
-	struct pnfs_block_extent *be = NULL, *cow_read = NULL;
+	struct pnfs_block_extent be;
 	sector_t isect, extent_length = 0;
 	struct parallel_io *par;
-	loff_t f_offset = hdr->args.offset;
-	size_t bytes_left = hdr->args.count;
+	loff_t f_offset = header->args.offset;
+	size_t bytes_left = header->args.count;
 	unsigned int pg_offset, pg_len;
-	struct page **pages = hdr->args.pages;
-	int pg_index = hdr->args.pgbase >> PAGE_CACHE_SHIFT;
+	struct page **pages = header->args.pages;
+	int pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT;
 	const bool is_dio = (header->dreq != NULL);
+	struct blk_plug plug;
+	int i;
 
 	dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
-		hdr->page_array.npages, f_offset,
-		(unsigned int)hdr->args.count);
+		header->page_array.npages, f_offset,
+		(unsigned int)header->args.count);
 
-	par = alloc_parallel(hdr);
+	par = alloc_parallel(header);
 	if (!par)
-		goto use_mds;
+		return PNFS_NOT_ATTEMPTED;
 	par->pnfs_callback = bl_end_par_io_read;
-	/* At this point, we can no longer jump to use_mds */
+
+	blk_start_plug(&plug);
 
 	isect = (sector_t) (f_offset >> SECTOR_SHIFT);
 	/* Code assumes extents are page-aligned */
-	for (i = pg_index; i < hdr->page_array.npages; i++) {
-		if (!extent_length) {
+	for (i = pg_index; i < header->page_array.npages; i++) {
+		if (extent_length <= 0) {
 			/* We've used up the previous extent */
-			bl_put_extent(be);
-			bl_put_extent(cow_read);
 			bio = bl_submit_bio(READ, bio);
+
 			/* Get the next one */
-			be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
-					     isect, &cow_read);
-			if (!be) {
+			if (!ext_tree_lookup(bl, isect, &be, false)) {
 				header->pnfs_error = -EIO;
 				goto out;
 			}
-			extent_length = be->be_length -
-				(isect - be->be_f_offset);
-			if (cow_read) {
-				sector_t cow_length = cow_read->be_length -
-					(isect - cow_read->be_f_offset);
-				extent_length = min(extent_length, cow_length);
-			}
+			extent_length = be.be_length - (isect - be.be_f_offset);
 		}
 
+		pg_offset = f_offset & ~PAGE_CACHE_MASK;
 		if (is_dio) {
-			pg_offset = f_offset & ~PAGE_CACHE_MASK;
 			if (pg_offset + bytes_left > PAGE_CACHE_SIZE)
 				pg_len = PAGE_CACHE_SIZE - pg_offset;
 			else
 				pg_len = bytes_left;
-
-			f_offset += pg_len;
-			bytes_left -= pg_len;
-			isect += (pg_offset >> SECTOR_SHIFT);
 		} else {
-			pg_offset = 0;
+			BUG_ON(pg_offset != 0);
 			pg_len = PAGE_CACHE_SIZE;
 		}
 
-		hole = is_hole(be, isect);
-		if (hole && !cow_read) {
+		isect += (pg_offset >> SECTOR_SHIFT);
+		extent_length -= (pg_offset >> SECTOR_SHIFT);
+
+		if (is_hole(&be)) {
 			bio = bl_submit_bio(READ, bio);
 			/* Fill hole w/ zeroes w/o accessing device */
 			dprintk("%s Zeroing page for hole\n", __func__);
 			zero_user_segment(pages[i], pg_offset, pg_len);
-			print_page(pages[i]);
-			SetPageUptodate(pages[i]);
-		} else {
-			struct pnfs_block_extent *be_read;
 
-			be_read = (hole && cow_read) ? cow_read : be;
+			/* invalidate map */
+			map.start = NFS4_MAX_UINT64;
+		} else {
 			bio = do_add_page_to_bio(bio,
-						 hdr->page_array.npages - i,
+						 header->page_array.npages - i,
 						 READ,
-						 isect, pages[i], be_read,
+						 isect, pages[i], &map, &be,
 						 bl_end_io_read, par,
-						 pg_offset, pg_len);
+						 pg_offset, &pg_len);
 			if (IS_ERR(bio)) {
 				header->pnfs_error = PTR_ERR(bio);
 				bio = NULL;
@@ -330,75 +299,21 @@ bl_read_pagelist(struct nfs_pgio_header *hdr)
 			}
 		}
 		isect += (pg_len >> SECTOR_SHIFT);
-		extent_length -= PAGE_CACHE_SECTORS;
+		extent_length -= (pg_len >> SECTOR_SHIFT);
+		f_offset += pg_len;
+		bytes_left -= pg_len;
 	}
 	if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
-		hdr->res.eof = 1;
-		hdr->res.count = header->inode->i_size - hdr->args.offset;
+		header->res.eof = 1;
+		header->res.count = header->inode->i_size - header->args.offset;
 	} else {
-		hdr->res.count = (isect << SECTOR_SHIFT) - hdr->args.offset;
+		header->res.count = (isect << SECTOR_SHIFT) - header->args.offset;
 	}
 out:
-	bl_put_extent(be);
-	bl_put_extent(cow_read);
 	bl_submit_bio(READ, bio);
+	blk_finish_plug(&plug);
 	put_parallel(par);
 	return PNFS_ATTEMPTED;
-
- use_mds:
-	dprintk("Giving up and using normal NFS\n");
-	return PNFS_NOT_ATTEMPTED;
-}
-
-static void mark_extents_written(struct pnfs_block_layout *bl,
-				 __u64 offset, __u32 count)
-{
-	sector_t isect, end;
-	struct pnfs_block_extent *be;
-	struct pnfs_block_short_extent *se;
-
-	dprintk("%s(%llu, %u)\n", __func__, offset, count);
-	if (count == 0)
-		return;
-	isect = (offset & (long)(PAGE_CACHE_MASK)) >> SECTOR_SHIFT;
-	end = (offset + count + PAGE_CACHE_SIZE - 1) & (long)(PAGE_CACHE_MASK);
-	end >>= SECTOR_SHIFT;
-	while (isect < end) {
-		sector_t len;
-		be = bl_find_get_extent(bl, isect, NULL);
-		BUG_ON(!be); /* FIXME */
-		len = min(end, be->be_f_offset + be->be_length) - isect;
-		if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
-			se = bl_pop_one_short_extent(be->be_inval);
-			BUG_ON(!se);
-			bl_mark_for_commit(be, isect, len, se);
-		}
-		isect += len;
-		bl_put_extent(be);
-	}
-}
-
-static void bl_end_io_write_zero(struct bio *bio, int err)
-{
-	struct parallel_io *par = bio->bi_private;
-	struct bio_vec *bvec;
-	int i;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		/* This is the zeroing page we added */
-		end_page_writeback(bvec->bv_page);
-		page_cache_release(bvec->bv_page);
-	}
-
-	if (unlikely(err)) {
-		struct nfs_pgio_header *header = par->data;
-
-		if (!header->pnfs_error)
-			header->pnfs_error = -EIO;
-		pnfs_set_lo_fail(header->lseg);
-	}
-	bio_put(bio);
-	put_parallel(par);
 }
 
 static void bl_end_io_write(struct bio *bio, int err)
@@ -421,533 +336,118 @@ static void bl_end_io_write(struct bio *bio, int err)
  */
 static void bl_write_cleanup(struct work_struct *work)
 {
-	struct rpc_task *task;
-	struct nfs_pgio_header *hdr;
+	struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work);
+	struct nfs_pgio_header *hdr =
+			container_of(task, struct nfs_pgio_header, task);
+
 	dprintk("%s enter\n", __func__);
-	task = container_of(work, struct rpc_task, u.tk_work);
-	hdr = container_of(task, struct nfs_pgio_header, task);
+
 	if (likely(!hdr->pnfs_error)) {
-		/* Marks for LAYOUTCOMMIT */
-		mark_extents_written(BLK_LSEG2EXT(hdr->lseg),
-				     hdr->args.offset, hdr->args.count);
+		struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg);
+		u64 start = hdr->args.offset & (loff_t)PAGE_CACHE_MASK;
+		u64 end = (hdr->args.offset + hdr->args.count +
+			PAGE_CACHE_SIZE - 1) & (loff_t)PAGE_CACHE_MASK;
+
+		ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
+					(end - start) >> SECTOR_SHIFT);
 	}
+
 	pnfs_ld_write_done(hdr);
 }
 
 /* Called when last of bios associated with a bl_write_pagelist call finishes */
-static void bl_end_par_io_write(void *data, int num_se)
+static void bl_end_par_io_write(void *data)
 {
 	struct nfs_pgio_header *hdr = data;
 
-	if (unlikely(hdr->pnfs_error)) {
-		bl_free_short_extents(&BLK_LSEG2EXT(hdr->lseg)->bl_inval,
-					num_se);
-	}
-
 	hdr->task.tk_status = hdr->pnfs_error;
 	hdr->verf.committed = NFS_FILE_SYNC;
 	INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup);
 	schedule_work(&hdr->task.u.tk_work);
 }
 
-/* FIXME STUB - mark intersection of layout and page as bad, so is not
- * used again.
- */
-static void mark_bad_read(void)
-{
-	return;
-}
-
-/*
- * map_block:  map a requested I/0 block (isect) into an offset in the LVM
- * block_device
- */
-static void
-map_block(struct buffer_head *bh, sector_t isect, struct pnfs_block_extent *be)
-{
-	dprintk("%s enter be=%p\n", __func__, be);
-
-	set_buffer_mapped(bh);
-	bh->b_bdev = be->be_mdev;
-	bh->b_blocknr = (isect - be->be_f_offset + be->be_v_offset) >>
-	    (be->be_mdev->bd_inode->i_blkbits - SECTOR_SHIFT);
-
-	dprintk("%s isect %llu, bh->b_blocknr %ld, using bsize %Zd\n",
-		__func__, (unsigned long long)isect, (long)bh->b_blocknr,
-		bh->b_size);
-	return;
-}
-
-static void
-bl_read_single_end_io(struct bio *bio, int error)
-{
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct page *page = bvec->bv_page;
-
-	/* Only one page in bvec */
-	unlock_page(page);
-}
-
-static int
-bl_do_readpage_sync(struct page *page, struct pnfs_block_extent *be,
-		    unsigned int offset, unsigned int len)
-{
-	struct bio *bio;
-	struct page *shadow_page;
-	sector_t isect;
-	char *kaddr, *kshadow_addr;
-	int ret = 0;
-
-	dprintk("%s: offset %u len %u\n", __func__, offset, len);
-
-	shadow_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
-	if (shadow_page == NULL)
-		return -ENOMEM;
-
-	bio = bio_alloc(GFP_NOIO, 1);
-	if (bio == NULL)
-		return -ENOMEM;
-
-	isect = (page->index << PAGE_CACHE_SECTOR_SHIFT) +
-		(offset / SECTOR_SIZE);
-
-	bio->bi_iter.bi_sector = isect - be->be_f_offset + be->be_v_offset;
-	bio->bi_bdev = be->be_mdev;
-	bio->bi_end_io = bl_read_single_end_io;
-
-	lock_page(shadow_page);
-	if (bio_add_page(bio, shadow_page,
-			 SECTOR_SIZE, round_down(offset, SECTOR_SIZE)) == 0) {
-		unlock_page(shadow_page);
-		bio_put(bio);
-		return -EIO;
-	}
-
-	submit_bio(READ, bio);
-	wait_on_page_locked(shadow_page);
-	if (unlikely(!test_bit(BIO_UPTODATE, &bio->bi_flags))) {
-		ret = -EIO;
-	} else {
-		kaddr = kmap_atomic(page);
-		kshadow_addr = kmap_atomic(shadow_page);
-		memcpy(kaddr + offset, kshadow_addr + offset, len);
-		kunmap_atomic(kshadow_addr);
-		kunmap_atomic(kaddr);
-	}
-	__free_page(shadow_page);
-	bio_put(bio);
-
-	return ret;
-}
-
-static int
-bl_read_partial_page_sync(struct page *page, struct pnfs_block_extent *be,
-			  unsigned int dirty_offset, unsigned int dirty_len,
-			  bool full_page)
-{
-	int ret = 0;
-	unsigned int start, end;
-
-	if (full_page) {
-		start = 0;
-		end = PAGE_CACHE_SIZE;
-	} else {
-		start = round_down(dirty_offset, SECTOR_SIZE);
-		end = round_up(dirty_offset + dirty_len, SECTOR_SIZE);
-	}
-
-	dprintk("%s: offset %u len %d\n", __func__, dirty_offset, dirty_len);
-	if (!be) {
-		zero_user_segments(page, start, dirty_offset,
-				   dirty_offset + dirty_len, end);
-		if (start == 0 && end == PAGE_CACHE_SIZE &&
-		    trylock_page(page)) {
-			SetPageUptodate(page);
-			unlock_page(page);
-		}
-		return ret;
-	}
-
-	if (start != dirty_offset)
-		ret = bl_do_readpage_sync(page, be, start, dirty_offset - start);
-
-	if (!ret && (dirty_offset + dirty_len < end))
-		ret = bl_do_readpage_sync(page, be, dirty_offset + dirty_len,
-					  end - dirty_offset - dirty_len);
-
-	return ret;
-}
-
-/* Given an unmapped page, zero it or read in page for COW, page is locked
- * by caller.
- */
-static int
-init_page_for_write(struct page *page, struct pnfs_block_extent *cow_read)
-{
-	struct buffer_head *bh = NULL;
-	int ret = 0;
-	sector_t isect;
-
-	dprintk("%s enter, %p\n", __func__, page);
-	BUG_ON(PageUptodate(page));
-	if (!cow_read) {
-		zero_user_segment(page, 0, PAGE_SIZE);
-		SetPageUptodate(page);
-		goto cleanup;
-	}
-
-	bh = alloc_page_buffers(page, PAGE_CACHE_SIZE, 0);
-	if (!bh) {
-		ret = -ENOMEM;
-		goto cleanup;
-	}
-
-	isect = (sector_t) page->index << PAGE_CACHE_SECTOR_SHIFT;
-	map_block(bh, isect, cow_read);
-	if (!bh_uptodate_or_lock(bh))
-		ret = bh_submit_read(bh);
-	if (ret)
-		goto cleanup;
-	SetPageUptodate(page);
-
-cleanup:
-	if (bh)
-		free_buffer_head(bh);
-	if (ret) {
-		/* Need to mark layout with bad read...should now
-		 * just use nfs4 for reads and writes.
-		 */
-		mark_bad_read();
-	}
-	return ret;
-}
-
-/* Find or create a zeroing page marked being writeback.
- * Return ERR_PTR on error, NULL to indicate skip this page and page itself
- * to indicate write out.
- */
-static struct page *
-bl_find_get_zeroing_page(struct inode *inode, pgoff_t index,
-			struct pnfs_block_extent *cow_read)
-{
-	struct page *page;
-	int locked = 0;
-	page = find_get_page(inode->i_mapping, index);
-	if (page)
-		goto check_page;
-
-	page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
-	if (unlikely(!page)) {
-		dprintk("%s oom\n", __func__);
-		return ERR_PTR(-ENOMEM);
-	}
-	locked = 1;
-
-check_page:
-	/* PageDirty: Other will write this out
-	 * PageWriteback: Other is writing this out
-	 * PageUptodate: It was read before
-	 */
-	if (PageDirty(page) || PageWriteback(page)) {
-		print_page(page);
-		if (locked)
-			unlock_page(page);
-		page_cache_release(page);
-		return NULL;
-	}
-
-	if (!locked) {
-		lock_page(page);
-		locked = 1;
-		goto check_page;
-	}
-	if (!PageUptodate(page)) {
-		/* New page, readin or zero it */
-		init_page_for_write(page, cow_read);
-	}
-	set_page_writeback(page);
-	unlock_page(page);
-
-	return page;
-}
-
 static enum pnfs_try_status
 bl_write_pagelist(struct nfs_pgio_header *header, int sync)
 {
-	int i, ret, npg_zero, pg_index, last = 0;
+	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
+	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
 	struct bio *bio = NULL;
-	struct pnfs_block_extent *be = NULL, *cow_read = NULL;
-	sector_t isect, last_isect = 0, extent_length = 0;
+	struct pnfs_block_extent be;
+	sector_t isect, extent_length = 0;
 	struct parallel_io *par = NULL;
 	loff_t offset = header->args.offset;
 	size_t count = header->args.count;
-	unsigned int pg_offset, pg_len, saved_len;
 	struct page **pages = header->args.pages;
-	struct page *page;
-	pgoff_t index;
-	u64 temp;
-	int npg_per_block =
-	    NFS_SERVER(header->inode)->pnfs_blksize >> PAGE_CACHE_SHIFT;
+	int pg_index = pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT;
+	unsigned int pg_len;
+	struct blk_plug plug;
+	int i;
 
 	dprintk("%s enter, %Zu@%lld\n", __func__, count, offset);
 
-	if (header->dreq != NULL &&
-	    (!IS_ALIGNED(offset, NFS_SERVER(header->inode)->pnfs_blksize) ||
-	     !IS_ALIGNED(count, NFS_SERVER(header->inode)->pnfs_blksize))) {
-		dprintk("pnfsblock nonblock aligned DIO writes. Resend MDS\n");
-		goto out_mds;
-	}
 	/* At this point, header->page_aray is a (sequential) list of nfs_pages.
 	 * We want to write each, and if there is an error set pnfs_error
 	 * to have it redone using nfs.
 	 */
 	par = alloc_parallel(header);
 	if (!par)
-		goto out_mds;
+		return PNFS_NOT_ATTEMPTED;
 	par->pnfs_callback = bl_end_par_io_write;
-	/* At this point, have to be more careful with error handling */
 
-	isect = (sector_t) ((offset & (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
-	be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg), isect, &cow_read);
-	if (!be || !is_writable(be, isect)) {
-		dprintk("%s no matching extents!\n", __func__);
-		goto out_mds;
-	}
+	blk_start_plug(&plug);
 
-	/* First page inside INVALID extent */
-	if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
-		if (likely(!bl_push_one_short_extent(be->be_inval)))
-			par->bse_count++;
-		else
-			goto out_mds;
-		temp = offset >> PAGE_CACHE_SHIFT;
-		npg_zero = do_div(temp, npg_per_block);
-		isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
-				     (long)PAGE_CACHE_MASK) >> SECTOR_SHIFT);
-		extent_length = be->be_length - (isect - be->be_f_offset);
-
-fill_invalid_ext:
-		dprintk("%s need to zero %d pages\n", __func__, npg_zero);
-		for (;npg_zero > 0; npg_zero--) {
-			if (bl_is_sector_init(be->be_inval, isect)) {
-				dprintk("isect %llu already init\n",
-					(unsigned long long)isect);
-				goto next_page;
-			}
-			/* page ref released in bl_end_io_write_zero */
-			index = isect >> PAGE_CACHE_SECTOR_SHIFT;
-			dprintk("%s zero %dth page: index %lu isect %llu\n",
-				__func__, npg_zero, index,
-				(unsigned long long)isect);
-			page = bl_find_get_zeroing_page(header->inode, index,
-							cow_read);
-			if (unlikely(IS_ERR(page))) {
-				header->pnfs_error = PTR_ERR(page);
-				goto out;
-			} else if (page == NULL)
-				goto next_page;
-
-			ret = bl_mark_sectors_init(be->be_inval, isect,
-						       PAGE_CACHE_SECTORS);
-			if (unlikely(ret)) {
-				dprintk("%s bl_mark_sectors_init fail %d\n",
-					__func__, ret);
-				end_page_writeback(page);
-				page_cache_release(page);
-				header->pnfs_error = ret;
-				goto out;
-			}
-			if (likely(!bl_push_one_short_extent(be->be_inval)))
-				par->bse_count++;
-			else {
-				end_page_writeback(page);
-				page_cache_release(page);
-				header->pnfs_error = -ENOMEM;
-				goto out;
-			}
-			/* FIXME: This should be done in bi_end_io */
-			mark_extents_written(BLK_LSEG2EXT(header->lseg),
-					     page->index << PAGE_CACHE_SHIFT,
-					     PAGE_CACHE_SIZE);
-
-			bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
-						 isect, page, be,
-						 bl_end_io_write_zero, par);
-			if (IS_ERR(bio)) {
-				header->pnfs_error = PTR_ERR(bio);
-				bio = NULL;
-				goto out;
-			}
-next_page:
-			isect += PAGE_CACHE_SECTORS;
-			extent_length -= PAGE_CACHE_SECTORS;
-		}
-		if (last)
-			goto write_done;
-	}
-	bio = bl_submit_bio(WRITE, bio);
+	/* we always write out the whole page */
+	offset = offset & (loff_t)PAGE_CACHE_MASK;
+	isect = offset >> SECTOR_SHIFT;
 
-	/* Middle pages */
-	pg_index = header->args.pgbase >> PAGE_CACHE_SHIFT;
 	for (i = pg_index; i < header->page_array.npages; i++) {
-		if (!extent_length) {
+		if (extent_length <= 0) {
 			/* We've used up the previous extent */
-			bl_put_extent(be);
-			bl_put_extent(cow_read);
 			bio = bl_submit_bio(WRITE, bio);
 			/* Get the next one */
-			be = bl_find_get_extent(BLK_LSEG2EXT(header->lseg),
-					     isect, &cow_read);
-			if (!be || !is_writable(be, isect)) {
+			if (!ext_tree_lookup(bl, isect, &be, true)) {
 				header->pnfs_error = -EINVAL;
 				goto out;
 			}
-			if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
-				if (likely(!bl_push_one_short_extent(
-								be->be_inval)))
-					par->bse_count++;
-				else {
-					header->pnfs_error = -ENOMEM;
-					goto out;
-				}
-			}
-			extent_length = be->be_length -
-			    (isect - be->be_f_offset);
-		}
-
-		dprintk("%s offset %lld count %Zu\n", __func__, offset, count);
-		pg_offset = offset & ~PAGE_CACHE_MASK;
-		if (pg_offset + count > PAGE_CACHE_SIZE)
-			pg_len = PAGE_CACHE_SIZE - pg_offset;
-		else
-			pg_len = count;
-
-		saved_len = pg_len;
-		if (be->be_state == PNFS_BLOCK_INVALID_DATA &&
-		    !bl_is_sector_init(be->be_inval, isect)) {
-			ret = bl_read_partial_page_sync(pages[i], cow_read,
-							pg_offset, pg_len, true);
-			if (ret) {
-				dprintk("%s bl_read_partial_page_sync fail %d\n",
-					__func__, ret);
-				header->pnfs_error = ret;
-				goto out;
-			}
-
-			ret = bl_mark_sectors_init(be->be_inval, isect,
-						       PAGE_CACHE_SECTORS);
-			if (unlikely(ret)) {
-				dprintk("%s bl_mark_sectors_init fail %d\n",
-					__func__, ret);
-				header->pnfs_error = ret;
-				goto out;
-			}
 
-			/* Expand to full page write */
-			pg_offset = 0;
-			pg_len = PAGE_CACHE_SIZE;
-		} else if  ((pg_offset & (SECTOR_SIZE - 1)) ||
-			    (pg_len & (SECTOR_SIZE - 1))){
-			/* ahh, nasty case. We have to do sync full sector
-			 * read-modify-write cycles.
-			 */
-			unsigned int saved_offset = pg_offset;
-			ret = bl_read_partial_page_sync(pages[i], be, pg_offset,
-							pg_len, false);
-			pg_offset = round_down(pg_offset, SECTOR_SIZE);
-			pg_len = round_up(saved_offset + pg_len, SECTOR_SIZE)
-				 - pg_offset;
+			extent_length = be.be_length - (isect - be.be_f_offset);
 		}
 
-
+		pg_len = PAGE_CACHE_SIZE;
 		bio = do_add_page_to_bio(bio, header->page_array.npages - i,
-					 WRITE,
-					 isect, pages[i], be,
+					 WRITE, isect, pages[i], &map, &be,
 					 bl_end_io_write, par,
-					 pg_offset, pg_len);
+					 0, &pg_len);
 		if (IS_ERR(bio)) {
 			header->pnfs_error = PTR_ERR(bio);
 			bio = NULL;
 			goto out;
 		}
-		offset += saved_len;
-		count -= saved_len;
-		isect += PAGE_CACHE_SECTORS;
-		last_isect = isect;
-		extent_length -= PAGE_CACHE_SECTORS;
-	}
 
-	/* Last page inside INVALID extent */
-	if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
-		bio = bl_submit_bio(WRITE, bio);
-		temp = last_isect >> PAGE_CACHE_SECTOR_SHIFT;
-		npg_zero = npg_per_block - do_div(temp, npg_per_block);
-		if (npg_zero < npg_per_block) {
-			last = 1;
-			goto fill_invalid_ext;
-		}
+		offset += pg_len;
+		count -= pg_len;
+		isect += (pg_len >> SECTOR_SHIFT);
+		extent_length -= (pg_len >> SECTOR_SHIFT);
 	}
 
-write_done:
 	header->res.count = header->args.count;
 out:
-	bl_put_extent(be);
-	bl_put_extent(cow_read);
 	bl_submit_bio(WRITE, bio);
+	blk_finish_plug(&plug);
 	put_parallel(par);
 	return PNFS_ATTEMPTED;
-out_mds:
-	bl_put_extent(be);
-	bl_put_extent(cow_read);
-	kfree(par);
-	return PNFS_NOT_ATTEMPTED;
-}
-
-/* FIXME - range ignored */
-static void
-release_extents(struct pnfs_block_layout *bl, struct pnfs_layout_range *range)
-{
-	int i;
-	struct pnfs_block_extent *be;
-
-	spin_lock(&bl->bl_ext_lock);
-	for (i = 0; i < EXTENT_LISTS; i++) {
-		while (!list_empty(&bl->bl_extents[i])) {
-			be = list_first_entry(&bl->bl_extents[i],
-					      struct pnfs_block_extent,
-					      be_node);
-			list_del(&be->be_node);
-			bl_put_extent(be);
-		}
-	}
-	spin_unlock(&bl->bl_ext_lock);
-}
-
-static void
-release_inval_marks(struct pnfs_inval_markings *marks)
-{
-	struct pnfs_inval_tracking *pos, *temp;
-	struct pnfs_block_short_extent *se, *stemp;
-
-	list_for_each_entry_safe(pos, temp, &marks->im_tree.mtt_stub, it_link) {
-		list_del(&pos->it_link);
-		kfree(pos);
-	}
-
-	list_for_each_entry_safe(se, stemp, &marks->im_extents, bse_node) {
-		list_del(&se->bse_node);
-		kfree(se);
-	}
-	return;
 }
 
 static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
 {
 	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+	int err;
 
 	dprintk("%s enter\n", __func__);
-	release_extents(bl, NULL);
-	release_inval_marks(&bl->bl_inval);
+
+	err = ext_tree_remove(bl, true, 0, LLONG_MAX);
+	WARN_ON(err);
+
 	kfree(bl);
 }
 
@@ -960,14 +460,11 @@ static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
 	bl = kzalloc(sizeof(*bl), gfp_flags);
 	if (!bl)
 		return NULL;
+
+	bl->bl_ext_rw = RB_ROOT;
+	bl->bl_ext_ro = RB_ROOT;
 	spin_lock_init(&bl->bl_ext_lock);
-	INIT_LIST_HEAD(&bl->bl_extents[0]);
-	INIT_LIST_HEAD(&bl->bl_extents[1]);
-	INIT_LIST_HEAD(&bl->bl_commit);
-	INIT_LIST_HEAD(&bl->bl_committing);
-	bl->bl_count = 0;
-	bl->bl_blocksize = NFS_SERVER(inode)->pnfs_blksize >> SECTOR_SHIFT;
-	BL_INIT_INVAL_MARKS(&bl->bl_inval, bl->bl_blocksize);
+
 	return &bl->bl_layout;
 }
 
@@ -977,215 +474,318 @@ static void bl_free_lseg(struct pnfs_layout_segment *lseg)
 	kfree(lseg);
 }
 
-/* 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;
+/* Tracks info needed to ensure extents in layout obey constraints of spec */
+struct layout_verification {
+	u32 mode;	/* R or RW */
+	u64 start;	/* Expected start of next non-COW extent */
+	u64 inval;	/* Start of INVAL coverage */
+	u64 cowread;	/* End of COW read coverage */
+};
 
-	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);
-	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);
+/* Verify the extent meets the layout requirements of the pnfs-block draft,
+ * section 2.3.1.
+ */
+static int verify_extent(struct pnfs_block_extent *be,
+			 struct layout_verification *lv)
+{
+	if (lv->mode == IOMODE_READ) {
+		if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
+		    be->be_state == PNFS_BLOCK_INVALID_DATA)
+			return -EIO;
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		return 0;
 	}
-	return lseg;
+	/* lv->mode == IOMODE_RW */
+	if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		if (lv->cowread > lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		lv->inval = lv->start;
+		return 0;
+	} else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		return 0;
+	} else if (be->be_state == PNFS_BLOCK_READ_DATA) {
+		if (be->be_f_offset > lv->start)
+			return -EIO;
+		if (be->be_f_offset < lv->inval)
+			return -EIO;
+		if (be->be_f_offset < lv->cowread)
+			return -EIO;
+		/* It looks like you might want to min this with lv->start,
+		 * but you really don't.
+		 */
+		lv->inval = lv->inval + be->be_length;
+		lv->cowread = be->be_f_offset + be->be_length;
+		return 0;
+	} else
+		return -EIO;
 }
 
-static void
-bl_encode_layoutcommit(struct pnfs_layout_hdr *lo, struct xdr_stream *xdr,
-		       const struct nfs4_layoutcommit_args *arg)
+static int decode_sector_number(__be32 **rp, sector_t *sp)
 {
-	dprintk("%s enter\n", __func__);
-	encode_pnfs_block_layoutupdate(BLK_LO2EXT(lo), xdr, arg);
+	uint64_t s;
+
+	*rp = xdr_decode_hyper(*rp, &s);
+	if (s & 0x1ff) {
+		printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);
+		return -1;
+	}
+	*sp = s >> SECTOR_SHIFT;
+	return 0;
 }
 
-static void
-bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
+static int
+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_layout_hdr *lo = NFS_I(lcdata->args.inode)->layout;
+	struct pnfs_block_extent *be;
+	struct nfs4_deviceid id;
+	int error;
+	__be32 *p;
 
-	dprintk("%s enter\n", __func__);
-	clean_pnfs_block_layoutupdate(BLK_LO2EXT(lo), &lcdata->args, lcdata->res.status);
-}
+	p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
+	if (!p)
+		return -EIO;
 
-static void free_blk_mountid(struct block_mount_id *mid)
-{
-	if (mid) {
-		struct pnfs_block_dev *dev, *tmp;
+	be = kzalloc(sizeof(*be), GFP_NOFS);
+	if (!be)
+		return -ENOMEM;
 
-		/* No need to take bm_lock as we are last user freeing bm_devlist */
-		list_for_each_entry_safe(dev, tmp, &mid->bm_devlist, bm_node) {
-			list_del(&dev->bm_node);
-			bl_free_block_dev(dev);
-		}
-		kfree(mid);
+	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;
 }
 
-/* This is mostly copied from the filelayout_get_device_info function.
- * It seems much of this should be at the generic pnfs level.
- */
-static struct pnfs_block_dev *
-nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
-			struct nfs4_deviceid *d_id)
+static struct pnfs_layout_segment *
+bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
+		gfp_t gfp_mask)
 {
-	struct pnfs_device *dev;
-	struct pnfs_block_dev *rv;
-	u32 max_resp_sz;
-	int max_pages;
-	struct page **pages = NULL;
-	int i, rc;
+	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__);
+
+	lseg = kzalloc(sizeof(*lseg), gfp_mask);
+	if (!lseg)
+		return ERR_PTR(-ENOMEM);
+
+	status = -ENOMEM;
+	scratch = alloc_page(gfp_mask);
+	if (!scratch)
+		goto out;
+
+	xdr_init_decode_pages(&xdr, &buf,
+			lgr->layoutp->pages, lgr->layoutp->len);
+	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
+
+	status = -EIO;
+	p = xdr_inline_decode(&xdr, 4);
+	if (unlikely(!p))
+		goto out_free_scratch;
+
+	count = be32_to_cpup(p++);
+	dprintk("%s: number of extents %d\n", __func__, count);
 
 	/*
-	 * Use the session max response size as the basis for setting
-	 * GETDEVICEINFO's maxcount
+	 * Decode individual extents, putting them in temporary staging area
+	 * until whole layout is decoded to make error recovery easier.
 	 */
-	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
-	max_pages = nfs_page_array_len(0, max_resp_sz);
-	dprintk("%s max_resp_sz %u max_pages %d\n",
-		__func__, max_resp_sz, max_pages);
-
-	dev = kmalloc(sizeof(*dev), GFP_NOFS);
-	if (!dev) {
-		dprintk("%s kmalloc failed\n", __func__);
-		return ERR_PTR(-ENOMEM);
+	for (i = 0; i < count; i++) {
+		status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
+		if (status)
+			goto process_extents;
 	}
 
-	pages = kcalloc(max_pages, sizeof(struct page *), GFP_NOFS);
-	if (pages == NULL) {
-		kfree(dev);
-		return ERR_PTR(-ENOMEM);
+	if (lgr->range.offset + lgr->range.length !=
+			lv.start << SECTOR_SHIFT) {
+		dprintk("%s Final length mismatch\n", __func__);
+		status = -EIO;
+		goto process_extents;
 	}
-	for (i = 0; i < max_pages; i++) {
-		pages[i] = alloc_page(GFP_NOFS);
-		if (!pages[i]) {
-			rv = ERR_PTR(-ENOMEM);
-			goto out_free;
-		}
+
+	if (lv.start < lv.cowread) {
+		dprintk("%s Final uncovered COW extent\n", __func__);
+		status = -EIO;
 	}
 
-	memcpy(&dev->dev_id, d_id, sizeof(*d_id));
-	dev->layout_type = LAYOUT_BLOCK_VOLUME;
-	dev->pages = pages;
-	dev->pgbase = 0;
-	dev->pglen = PAGE_SIZE * max_pages;
-	dev->mincount = 0;
-	dev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
-
-	dprintk("%s: dev_id: %s\n", __func__, dev->dev_id.data);
-	rc = nfs4_proc_getdeviceinfo(server, dev, NULL);
-	dprintk("%s getdevice info returns %d\n", __func__, rc);
-	if (rc) {
-		rv = ERR_PTR(rc);
-		goto out_free;
+process_extents:
+	while (!list_empty(&extents)) {
+		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);
+		}
 	}
 
-	rv = nfs4_blk_decode_device(server, dev);
- out_free:
-	for (i = 0; i < max_pages; i++)
-		__free_page(pages[i]);
-	kfree(pages);
-	kfree(dev);
-	return rv;
+out_free_scratch:
+	__free_page(scratch);
+out:
+	dprintk("%s returns %d\n", __func__, status);
+	if (status) {
+		kfree(lseg);
+		return ERR_PTR(status);
+	}
+	return lseg;
 }
 
-static int
-bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
+static void
+bl_return_range(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_range *range)
 {
-	struct block_mount_id *b_mt_id = NULL;
-	struct pnfs_devicelist *dlist = NULL;
-	struct pnfs_block_dev *bdev;
-	LIST_HEAD(block_disklist);
-	int status, i;
-
-	dprintk("%s enter\n", __func__);
+	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+	sector_t offset = range->offset >> SECTOR_SHIFT, end;
 
-	if (server->pnfs_blksize == 0) {
-		dprintk("%s Server did not return blksize\n", __func__);
-		return -EINVAL;
-	}
-	b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS);
-	if (!b_mt_id) {
-		status = -ENOMEM;
-		goto out_error;
-	}
-	/* Initialize nfs4 block layout mount id */
-	spin_lock_init(&b_mt_id->bm_lock);
-	INIT_LIST_HEAD(&b_mt_id->bm_devlist);
-
-	dlist = kmalloc(sizeof(struct pnfs_devicelist), GFP_NOFS);
-	if (!dlist) {
-		status = -ENOMEM;
-		goto out_error;
+	if (range->offset % 8) {
+		dprintk("%s: offset %lld not block size aligned\n",
+			__func__, range->offset);
+		return;
 	}
-	dlist->eof = 0;
-	while (!dlist->eof) {
-		status = nfs4_proc_getdevicelist(server, fh, dlist);
-		if (status)
-			goto out_error;
-		dprintk("%s GETDEVICELIST numdevs=%i, eof=%i\n",
-			__func__, dlist->num_devs, dlist->eof);
-		for (i = 0; i < dlist->num_devs; i++) {
-			bdev = nfs4_blk_get_deviceinfo(server, fh,
-						       &dlist->dev_id[i]);
-			if (IS_ERR(bdev)) {
-				status = PTR_ERR(bdev);
-				goto out_error;
-			}
-			spin_lock(&b_mt_id->bm_lock);
-			list_add(&bdev->bm_node, &b_mt_id->bm_devlist);
-			spin_unlock(&b_mt_id->bm_lock);
+
+	if (range->length != NFS4_MAX_UINT64) {
+		if (range->length % 8) {
+			dprintk("%s: length %lld not block size aligned\n",
+				__func__, range->length);
+			return;
 		}
-	}
-	dprintk("%s SUCCESS\n", __func__);
-	server->pnfs_ld_data = b_mt_id;
 
- out_return:
-	kfree(dlist);
-	return status;
+		end = offset + (range->length >> SECTOR_SHIFT);
+	} else {
+		end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
+	}
 
- out_error:
-	free_blk_mountid(b_mt_id);
-	goto out_return;
+	ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
 }
 
 static int
-bl_clear_layoutdriver(struct nfs_server *server)
+bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
+{
+	return ext_tree_prepare_commit(arg);
+}
+
+static void
+bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
 {
-	struct block_mount_id *b_mt_id = server->pnfs_ld_data;
+	ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
+}
 
+static int
+bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
+{
 	dprintk("%s enter\n", __func__);
-	free_blk_mountid(b_mt_id);
-	dprintk("%s RETURNS\n", __func__);
+
+	if (server->pnfs_blksize == 0) {
+		dprintk("%s Server did not return blksize\n", __func__);
+		return -EINVAL;
+	}
+	if (server->pnfs_blksize > PAGE_SIZE) {
+		printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
+			__func__, server->pnfs_blksize);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
 static bool
-is_aligned_req(struct nfs_page *req, unsigned int alignment)
+is_aligned_req(struct nfs_pageio_descriptor *pgio,
+		struct nfs_page *req, unsigned int alignment)
 {
-	return IS_ALIGNED(req->wb_offset, alignment) &&
-	       IS_ALIGNED(req->wb_bytes, alignment);
+	/*
+	 * Always accept buffered writes, higher layers take care of the
+	 * right alignment.
+	 */
+	if (pgio->pg_dreq == NULL)
+		return true;
+
+	if (!IS_ALIGNED(req->wb_offset, alignment))
+		return false;
+
+	if (IS_ALIGNED(req->wb_bytes, alignment))
+		return true;
+
+	if (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode)) {
+		/*
+		 * If the write goes up to the inode size, just write
+		 * the full page.  Data past the inode size is
+		 * guaranteed to be zeroed by the higher level client
+		 * code, and this behaviour is mandated by RFC 5663
+		 * section 2.3.2.
+		 */
+		return true;
+	}
+
+	return false;
 }
 
 static void
 bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 {
-	if (pgio->pg_dreq != NULL &&
-	    !is_aligned_req(req, SECTOR_SIZE))
+	if (!is_aligned_req(pgio, req, SECTOR_SIZE)) {
 		nfs_pageio_reset_read_mds(pgio);
-	else
-		pnfs_generic_pg_init_read(pgio, req);
+		return;
+	}
+
+	pnfs_generic_pg_init_read(pgio, req);
 }
 
 /*
@@ -1196,10 +796,8 @@ static size_t
 bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 		struct nfs_page *req)
 {
-	if (pgio->pg_dreq != NULL &&
-	    !is_aligned_req(req, SECTOR_SIZE))
+	if (!is_aligned_req(pgio, req, SECTOR_SIZE))
 		return 0;
-
 	return pnfs_generic_pg_test(pgio, prev, req);
 }
 
@@ -1229,19 +827,20 @@ static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
 static void
 bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
 {
-	if (pgio->pg_dreq != NULL &&
-	    !is_aligned_req(req, PAGE_CACHE_SIZE)) {
+	u64 wb_size;
+
+	if (!is_aligned_req(pgio, req, PAGE_SIZE)) {
 		nfs_pageio_reset_write_mds(pgio);
-	} else {
-		u64 wb_size;
-		if (pgio->pg_dreq == NULL)
-			wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
-						      req->wb_index);
-		else
-			wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
-
-		pnfs_generic_pg_init_write(pgio, req, wb_size);
+		return;
 	}
+
+	if (pgio->pg_dreq == NULL)
+		wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
+					      req->wb_index);
+	else
+		wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
+	pnfs_generic_pg_init_write(pgio, req, wb_size);
 }
 
 /*
@@ -1252,10 +851,8 @@ static size_t
 bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 		 struct nfs_page *req)
 {
-	if (pgio->pg_dreq != NULL &&
-	    !is_aligned_req(req, PAGE_CACHE_SIZE))
+	if (!is_aligned_req(pgio, req, PAGE_SIZE))
 		return 0;
-
 	return pnfs_generic_pg_test(pgio, prev, req);
 }
 
@@ -1275,146 +872,24 @@ static struct pnfs_layoutdriver_type blocklayout_type = {
 	.id				= LAYOUT_BLOCK_VOLUME,
 	.name				= "LAYOUT_BLOCK_VOLUME",
 	.owner				= THIS_MODULE,
+	.flags				= PNFS_LAYOUTRET_ON_SETATTR |
+					  PNFS_READ_WHOLE_PAGE,
 	.read_pagelist			= bl_read_pagelist,
 	.write_pagelist			= bl_write_pagelist,
 	.alloc_layout_hdr		= bl_alloc_layout_hdr,
 	.free_layout_hdr		= bl_free_layout_hdr,
 	.alloc_lseg			= bl_alloc_lseg,
 	.free_lseg			= bl_free_lseg,
-	.encode_layoutcommit		= bl_encode_layoutcommit,
+	.return_range			= bl_return_range,
+	.prepare_layoutcommit		= bl_prepare_layoutcommit,
 	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
 	.set_layoutdriver		= bl_set_layoutdriver,
-	.clear_layoutdriver		= bl_clear_layoutdriver,
+	.alloc_deviceid_node		= bl_alloc_deviceid_node,
+	.free_deviceid_node		= bl_free_deviceid_node,
 	.pg_read_ops			= &bl_pg_read_ops,
 	.pg_write_ops			= &bl_pg_write_ops,
 };
 
-static const struct rpc_pipe_ops bl_upcall_ops = {
-	.upcall		= rpc_pipe_generic_upcall,
-	.downcall	= bl_pipe_downcall,
-	.destroy_msg	= bl_pipe_destroy_msg,
-};
-
-static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
-					    struct rpc_pipe *pipe)
-{
-	struct dentry *dir, *dentry;
-
-	dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
-	if (dir == NULL)
-		return ERR_PTR(-ENOENT);
-	dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
-	dput(dir);
-	return dentry;
-}
-
-static void nfs4blocklayout_unregister_sb(struct super_block *sb,
-					  struct rpc_pipe *pipe)
-{
-	if (pipe->dentry)
-		rpc_unlink(pipe->dentry);
-}
-
-static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
-			   void *ptr)
-{
-	struct super_block *sb = ptr;
-	struct net *net = sb->s_fs_info;
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct dentry *dentry;
-	int ret = 0;
-
-	if (!try_module_get(THIS_MODULE))
-		return 0;
-
-	if (nn->bl_device_pipe == NULL) {
-		module_put(THIS_MODULE);
-		return 0;
-	}
-
-	switch (event) {
-	case RPC_PIPEFS_MOUNT:
-		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
-		if (IS_ERR(dentry)) {
-			ret = PTR_ERR(dentry);
-			break;
-		}
-		nn->bl_device_pipe->dentry = dentry;
-		break;
-	case RPC_PIPEFS_UMOUNT:
-		if (nn->bl_device_pipe->dentry)
-			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
-		break;
-	default:
-		ret = -ENOTSUPP;
-		break;
-	}
-	module_put(THIS_MODULE);
-	return ret;
-}
-
-static struct notifier_block nfs4blocklayout_block = {
-	.notifier_call = rpc_pipefs_event,
-};
-
-static struct dentry *nfs4blocklayout_register_net(struct net *net,
-						   struct rpc_pipe *pipe)
-{
-	struct super_block *pipefs_sb;
-	struct dentry *dentry;
-
-	pipefs_sb = rpc_get_sb_net(net);
-	if (!pipefs_sb)
-		return NULL;
-	dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
-	rpc_put_sb_net(net);
-	return dentry;
-}
-
-static void nfs4blocklayout_unregister_net(struct net *net,
-					   struct rpc_pipe *pipe)
-{
-	struct super_block *pipefs_sb;
-
-	pipefs_sb = rpc_get_sb_net(net);
-	if (pipefs_sb) {
-		nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
-		rpc_put_sb_net(net);
-	}
-}
-
-static int nfs4blocklayout_net_init(struct net *net)
-{
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct dentry *dentry;
-
-	init_waitqueue_head(&nn->bl_wq);
-	nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
-	if (IS_ERR(nn->bl_device_pipe))
-		return PTR_ERR(nn->bl_device_pipe);
-	dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
-	if (IS_ERR(dentry)) {
-		rpc_destroy_pipe_data(nn->bl_device_pipe);
-		return PTR_ERR(dentry);
-	}
-	nn->bl_device_pipe->dentry = dentry;
-	return 0;
-}
-
-static void nfs4blocklayout_net_exit(struct net *net)
-{
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-
-	nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
-	rpc_destroy_pipe_data(nn->bl_device_pipe);
-	nn->bl_device_pipe = NULL;
-}
-
-static struct pernet_operations nfs4blocklayout_net_ops = {
-	.init = nfs4blocklayout_net_init,
-	.exit = nfs4blocklayout_net_exit,
-};
-
 static int __init nfs4blocklayout_init(void)
 {
 	int ret;
@@ -1424,20 +899,14 @@ static int __init nfs4blocklayout_init(void)
 	ret = pnfs_register_layoutdriver(&blocklayout_type);
 	if (ret)
 		goto out;
-
-	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
+	ret = bl_init_pipefs();
 	if (ret)
-		goto out_remove;
-	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
-	if (ret)
-		goto out_notifier;
-out:
-	return ret;
+		goto out_unregister;
+	return 0;
 
-out_notifier:
-	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
-out_remove:
+out_unregister:
 	pnfs_unregister_layoutdriver(&blocklayout_type);
+out:
 	return ret;
 }
 
@@ -1446,8 +915,7 @@ static void __exit nfs4blocklayout_exit(void)
 	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
 	       __func__);
 
-	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
-	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
+	bl_cleanup_pipefs();
 	pnfs_unregister_layoutdriver(&blocklayout_type);
 }