Initial import

1 files changed, 1524 insertions, 0 deletions

diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
new file mode 100644
index 000000000..786e4cc8c
--- /dev/null
+++ b/fs/exofs/inode.c
@@ -0,0 +1,1524 @@
+/*
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com)
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <ooo@electrozaur.com>
+ *
+ * Copyrights for code taken from ext2:
+ *     Copyright (C) 1992, 1993, 1994, 1995
+ *     Remy Card (card@masi.ibp.fr)
+ *     Laboratoire MASI - Institut Blaise Pascal
+ *     Universite Pierre et Marie Curie (Paris VI)
+ *     from
+ *     linux/fs/minix/inode.c
+ *     Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This file is part of exofs.
+ *
+ * exofs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.  Since it is based on ext2, and the only
+ * valid version of GPL for the Linux kernel is version 2, the only valid
+ * version of GPL for exofs is version 2.
+ *
+ * exofs is distributed in the hope that 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with exofs; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/slab.h>
+
+#include "exofs.h"
+
+#define EXOFS_DBGMSG2(M...) do {} while (0)
+
+unsigned exofs_max_io_pages(struct ore_layout *layout,
+			    unsigned expected_pages)
+{
+	unsigned pages = min_t(unsigned, expected_pages,
+			       layout->max_io_length / PAGE_SIZE);
+
+	return pages;
+}
+
+struct page_collect {
+	struct exofs_sb_info *sbi;
+	struct inode *inode;
+	unsigned expected_pages;
+	struct ore_io_state *ios;
+
+	struct page **pages;
+	unsigned alloc_pages;
+	unsigned nr_pages;
+	unsigned long length;
+	loff_t pg_first; /* keep 64bit also in 32-arches */
+	bool read_4_write; /* This means two things: that the read is sync
+			    * And the pages should not be unlocked.
+			    */
+	struct page *that_locked_page;
+};
+
+static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
+		       struct inode *inode)
+{
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+
+	pcol->sbi = sbi;
+	pcol->inode = inode;
+	pcol->expected_pages = expected_pages;
+
+	pcol->ios = NULL;
+	pcol->pages = NULL;
+	pcol->alloc_pages = 0;
+	pcol->nr_pages = 0;
+	pcol->length = 0;
+	pcol->pg_first = -1;
+	pcol->read_4_write = false;
+	pcol->that_locked_page = NULL;
+}
+
+static void _pcol_reset(struct page_collect *pcol)
+{
+	pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
+
+	pcol->pages = NULL;
+	pcol->alloc_pages = 0;
+	pcol->nr_pages = 0;
+	pcol->length = 0;
+	pcol->pg_first = -1;
+	pcol->ios = NULL;
+	pcol->that_locked_page = NULL;
+
+	/* this is probably the end of the loop but in writes
+	 * it might not end here. don't be left with nothing
+	 */
+	if (!pcol->expected_pages)
+		pcol->expected_pages =
+				exofs_max_io_pages(&pcol->sbi->layout, ~0);
+}
+
+static int pcol_try_alloc(struct page_collect *pcol)
+{
+	unsigned pages;
+
+	/* TODO: easily support bio chaining */
+	pages =  exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
+
+	for (; pages; pages >>= 1) {
+		pcol->pages = kmalloc(pages * sizeof(struct page *),
+				      GFP_KERNEL);
+		if (likely(pcol->pages)) {
+			pcol->alloc_pages = pages;
+			return 0;
+		}
+	}
+
+	EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
+		  pcol->expected_pages);
+	return -ENOMEM;
+}
+
+static void pcol_free(struct page_collect *pcol)
+{
+	kfree(pcol->pages);
+	pcol->pages = NULL;
+
+	if (pcol->ios) {
+		ore_put_io_state(pcol->ios);
+		pcol->ios = NULL;
+	}
+}
+
+static int pcol_add_page(struct page_collect *pcol, struct page *page,
+			 unsigned len)
+{
+	if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
+		return -ENOMEM;
+
+	pcol->pages[pcol->nr_pages++] = page;
+	pcol->length += len;
+	return 0;
+}
+
+enum {PAGE_WAS_NOT_IN_IO = 17};
+static int update_read_page(struct page *page, int ret)
+{
+	switch (ret) {
+	case 0:
+		/* Everything is OK */
+		SetPageUptodate(page);
+		if (PageError(page))
+			ClearPageError(page);
+		break;
+	case -EFAULT:
+		/* In this case we were trying to read something that wasn't on
+		 * disk yet - return a page full of zeroes.  This should be OK,
+		 * because the object should be empty (if there was a write
+		 * before this read, the read would be waiting with the page
+		 * locked */
+		clear_highpage(page);
+
+		SetPageUptodate(page);
+		if (PageError(page))
+			ClearPageError(page);
+		EXOFS_DBGMSG("recovered read error\n");
+		/* fall through */
+	case PAGE_WAS_NOT_IN_IO:
+		ret = 0; /* recovered error */
+		break;
+	default:
+		SetPageError(page);
+	}
+	return ret;
+}
+
+static void update_write_page(struct page *page, int ret)
+{
+	if (unlikely(ret == PAGE_WAS_NOT_IN_IO))
+		return; /* don't pass start don't collect $200 */
+
+	if (ret) {
+		mapping_set_error(page->mapping, ret);
+		SetPageError(page);
+	}
+	end_page_writeback(page);
+}
+
+/* Called at the end of reads, to optionally unlock pages and update their
+ * status.
+ */
+static int __readpages_done(struct page_collect *pcol)
+{
+	int i;
+	u64 good_bytes;
+	u64 length = 0;
+	int ret = ore_check_io(pcol->ios, NULL);
+
+	if (likely(!ret)) {
+		good_bytes = pcol->length;
+		ret = PAGE_WAS_NOT_IN_IO;
+	} else {
+		good_bytes = 0;
+	}
+
+	EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
+		     " length=0x%lx nr_pages=%u\n",
+		     pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
+		     pcol->nr_pages);
+
+	for (i = 0; i < pcol->nr_pages; i++) {
+		struct page *page = pcol->pages[i];
+		struct inode *inode = page->mapping->host;
+		int page_stat;
+
+		if (inode != pcol->inode)
+			continue; /* osd might add more pages at end */
+
+		if (likely(length < good_bytes))
+			page_stat = 0;
+		else
+			page_stat = ret;
+
+		EXOFS_DBGMSG2("    readpages_done(0x%lx, 0x%lx) %s\n",
+			  inode->i_ino, page->index,
+			  page_stat ? "bad_bytes" : "good_bytes");
+
+		ret = update_read_page(page, page_stat);
+		if (!pcol->read_4_write)
+			unlock_page(page);
+		length += PAGE_SIZE;
+	}
+
+	pcol_free(pcol);
+	EXOFS_DBGMSG2("readpages_done END\n");
+	return ret;
+}
+
+/* callback of async reads */
+static void readpages_done(struct ore_io_state *ios, void *p)
+{
+	struct page_collect *pcol = p;
+
+	__readpages_done(pcol);
+	atomic_dec(&pcol->sbi->s_curr_pending);
+	kfree(pcol);
+}
+
+static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
+{
+	int i;
+
+	for (i = 0; i < pcol->nr_pages; i++) {
+		struct page *page = pcol->pages[i];
+
+		if (rw == READ)
+			update_read_page(page, ret);
+		else
+			update_write_page(page, ret);
+
+		unlock_page(page);
+	}
+}
+
+static int _maybe_not_all_in_one_io(struct ore_io_state *ios,
+	struct page_collect *pcol_src, struct page_collect *pcol)
+{
+	/* length was wrong or offset was not page aligned */
+	BUG_ON(pcol_src->nr_pages < ios->nr_pages);
+
+	if (pcol_src->nr_pages > ios->nr_pages) {
+		struct page **src_page;
+		unsigned pages_less = pcol_src->nr_pages - ios->nr_pages;
+		unsigned long len_less = pcol_src->length - ios->length;
+		unsigned i;
+		int ret;
+
+		/* This IO was trimmed */
+		pcol_src->nr_pages = ios->nr_pages;
+		pcol_src->length = ios->length;
+
+		/* Left over pages are passed to the next io */
+		pcol->expected_pages += pages_less;
+		pcol->nr_pages = pages_less;
+		pcol->length = len_less;
+		src_page = pcol_src->pages + pcol_src->nr_pages;
+		pcol->pg_first = (*src_page)->index;
+
+		ret = pcol_try_alloc(pcol);
+		if (unlikely(ret))
+			return ret;
+
+		for (i = 0; i < pages_less; ++i)
+			pcol->pages[i] = *src_page++;
+
+		EXOFS_DBGMSG("Length was adjusted nr_pages=0x%x "
+			"pages_less=0x%x expected_pages=0x%x "
+			"next_offset=0x%llx next_len=0x%lx\n",
+			pcol_src->nr_pages, pages_less, pcol->expected_pages,
+			pcol->pg_first * PAGE_SIZE, pcol->length);
+	}
+	return 0;
+}
+
+static int read_exec(struct page_collect *pcol)
+{
+	struct exofs_i_info *oi = exofs_i(pcol->inode);
+	struct ore_io_state *ios;
+	struct page_collect *pcol_copy = NULL;
+	int ret;
+
+	if (!pcol->pages)
+		return 0;
+
+	if (!pcol->ios) {
+		int ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, true,
+					     pcol->pg_first << PAGE_CACHE_SHIFT,
+					     pcol->length, &pcol->ios);
+
+		if (ret)
+			return ret;
+	}
+
+	ios = pcol->ios;
+	ios->pages = pcol->pages;
+
+	if (pcol->read_4_write) {
+		ore_read(pcol->ios);
+		return __readpages_done(pcol);
+	}
+
+	pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
+	if (!pcol_copy) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	*pcol_copy = *pcol;
+	ios->done = readpages_done;
+	ios->private = pcol_copy;
+
+	/* pages ownership was passed to pcol_copy */
+	_pcol_reset(pcol);
+
+	ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
+	if (unlikely(ret))
+		goto err;
+
+	EXOFS_DBGMSG2("read_exec(0x%lx) offset=0x%llx length=0x%llx\n",
+		pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
+
+	ret = ore_read(ios);
+	if (unlikely(ret))
+		goto err;
+
+	atomic_inc(&pcol->sbi->s_curr_pending);
+
+	return 0;
+
+err:
+	if (!pcol_copy) /* Failed before ownership transfer */
+		pcol_copy = pcol;
+	_unlock_pcol_pages(pcol_copy, ret, READ);
+	pcol_free(pcol_copy);
+	kfree(pcol_copy);
+
+	return ret;
+}
+
+/* readpage_strip is called either directly from readpage() or by the VFS from
+ * within read_cache_pages(), to add one more page to be read. It will try to
+ * collect as many contiguous pages as posible. If a discontinuity is
+ * encountered, or it runs out of resources, it will submit the previous segment
+ * and will start a new collection. Eventually caller must submit the last
+ * segment if present.
+ */
+static int readpage_strip(void *data, struct page *page)
+{
+	struct page_collect *pcol = data;
+	struct inode *inode = pcol->inode;
+	struct exofs_i_info *oi = exofs_i(inode);
+	loff_t i_size = i_size_read(inode);
+	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	size_t len;
+	int ret;
+
+	BUG_ON(!PageLocked(page));
+
+	/* FIXME: Just for debugging, will be removed */
+	if (PageUptodate(page))
+		EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
+			  page->index);
+
+	pcol->that_locked_page = page;
+
+	if (page->index < end_index)
+		len = PAGE_CACHE_SIZE;
+	else if (page->index == end_index)
+		len = i_size & ~PAGE_CACHE_MASK;
+	else
+		len = 0;
+
+	if (!len || !obj_created(oi)) {
+		/* this will be out of bounds, or doesn't exist yet.
+		 * Current page is cleared and the request is split
+		 */
+		clear_highpage(page);
+
+		SetPageUptodate(page);
+		if (PageError(page))
+			ClearPageError(page);
+
+		if (!pcol->read_4_write)
+			unlock_page(page);
+		EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
+			     "read_4_write=%d index=0x%lx end_index=0x%lx "
+			     "splitting\n", inode->i_ino, len,
+			     pcol->read_4_write, page->index, end_index);
+
+		return read_exec(pcol);
+	}
+
+try_again:
+
+	if (unlikely(pcol->pg_first == -1)) {
+		pcol->pg_first = page->index;
+	} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
+		   page->index)) {
+		/* Discontinuity detected, split the request */
+		ret = read_exec(pcol);
+		if (unlikely(ret))
+			goto fail;
+		goto try_again;
+	}
+
+	if (!pcol->pages) {
+		ret = pcol_try_alloc(pcol);
+		if (unlikely(ret))
+			goto fail;
+	}
+
+	if (len != PAGE_CACHE_SIZE)
+		zero_user(page, len, PAGE_CACHE_SIZE - len);
+
+	EXOFS_DBGMSG2("    readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
+		     inode->i_ino, page->index, len);
+
+	ret = pcol_add_page(pcol, page, len);
+	if (ret) {
+		EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
+			  "this_len=0x%zx nr_pages=%u length=0x%lx\n",
+			  page, len, pcol->nr_pages, pcol->length);
+
+		/* split the request, and start again with current page */
+		ret = read_exec(pcol);
+		if (unlikely(ret))
+			goto fail;
+
+		goto try_again;
+	}
+
+	return 0;
+
+fail:
+	/* SetPageError(page); ??? */
+	unlock_page(page);
+	return ret;
+}
+
+static int exofs_readpages(struct file *file, struct address_space *mapping,
+			   struct list_head *pages, unsigned nr_pages)
+{
+	struct page_collect pcol;
+	int ret;
+
+	_pcol_init(&pcol, nr_pages, mapping->host);
+
+	ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
+	if (ret) {
+		EXOFS_ERR("read_cache_pages => %d\n", ret);
+		return ret;
+	}
+
+	ret = read_exec(&pcol);
+	if (unlikely(ret))
+		return ret;
+
+	return read_exec(&pcol);
+}
+
+static int _readpage(struct page *page, bool read_4_write)
+{
+	struct page_collect pcol;
+	int ret;
+
+	_pcol_init(&pcol, 1, page->mapping->host);
+
+	pcol.read_4_write = read_4_write;
+	ret = readpage_strip(&pcol, page);
+	if (ret) {
+		EXOFS_ERR("_readpage => %d\n", ret);
+		return ret;
+	}
+
+	return read_exec(&pcol);
+}
+
+/*
+ * We don't need the file
+ */
+static int exofs_readpage(struct file *file, struct page *page)
+{
+	return _readpage(page, false);
+}
+
+/* Callback for osd_write. All writes are asynchronous */
+static void writepages_done(struct ore_io_state *ios, void *p)
+{
+	struct page_collect *pcol = p;
+	int i;
+	u64  good_bytes;
+	u64  length = 0;
+	int ret = ore_check_io(ios, NULL);
+
+	atomic_dec(&pcol->sbi->s_curr_pending);
+
+	if (likely(!ret)) {
+		good_bytes = pcol->length;
+		ret = PAGE_WAS_NOT_IN_IO;
+	} else {
+		good_bytes = 0;
+	}
+
+	EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
+		     " length=0x%lx nr_pages=%u\n",
+		     pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
+		     pcol->nr_pages);
+
+	for (i = 0; i < pcol->nr_pages; i++) {
+		struct page *page = pcol->pages[i];
+		struct inode *inode = page->mapping->host;
+		int page_stat;
+
+		if (inode != pcol->inode)
+			continue; /* osd might add more pages to a bio */
+
+		if (likely(length < good_bytes))
+			page_stat = 0;
+		else
+			page_stat = ret;
+
+		update_write_page(page, page_stat);
+		unlock_page(page);
+		EXOFS_DBGMSG2("    writepages_done(0x%lx, 0x%lx) status=%d\n",
+			     inode->i_ino, page->index, page_stat);
+
+		length += PAGE_SIZE;
+	}
+
+	pcol_free(pcol);
+	kfree(pcol);
+	EXOFS_DBGMSG2("writepages_done END\n");
+}
+
+static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
+{
+	struct page_collect *pcol = priv;
+	pgoff_t index = offset / PAGE_SIZE;
+
+	if (!pcol->that_locked_page ||
+	    (pcol->that_locked_page->index != index)) {
+		struct page *page;
+		loff_t i_size = i_size_read(pcol->inode);
+
+		if (offset >= i_size) {
+			*uptodate = true;
+			EXOFS_DBGMSG2("offset >= i_size index=0x%lx\n", index);
+			return ZERO_PAGE(0);
+		}
+
+		page =  find_get_page(pcol->inode->i_mapping, index);
+		if (!page) {
+			page = find_or_create_page(pcol->inode->i_mapping,
+						   index, GFP_NOFS);
+			if (unlikely(!page)) {
+				EXOFS_DBGMSG("grab_cache_page Failed "
+					"index=0x%llx\n", _LLU(index));
+				return NULL;
+			}
+			unlock_page(page);
+		}
+		if (PageDirty(page) || PageWriteback(page))
+			*uptodate = true;
+		else
+			*uptodate = PageUptodate(page);
+		EXOFS_DBGMSG2("index=0x%lx uptodate=%d\n", index, *uptodate);
+		return page;
+	} else {
+		EXOFS_DBGMSG2("YES that_locked_page index=0x%lx\n",
+			     pcol->that_locked_page->index);
+		*uptodate = true;
+		return pcol->that_locked_page;
+	}
+}
+
+static void __r4w_put_page(void *priv, struct page *page)
+{
+	struct page_collect *pcol = priv;
+
+	if ((pcol->that_locked_page != page) && (ZERO_PAGE(0) != page)) {
+		EXOFS_DBGMSG2("index=0x%lx\n", page->index);
+		page_cache_release(page);
+		return;
+	}
+	EXOFS_DBGMSG2("that_locked_page index=0x%lx\n",
+		     ZERO_PAGE(0) == page ? -1 : page->index);
+}
+
+static const struct _ore_r4w_op _r4w_op = {
+	.get_page = &__r4w_get_page,
+	.put_page = &__r4w_put_page,
+};
+
+static int write_exec(struct page_collect *pcol)
+{
+	struct exofs_i_info *oi = exofs_i(pcol->inode);
+	struct ore_io_state *ios;
+	struct page_collect *pcol_copy = NULL;
+	int ret;
+
+	if (!pcol->pages)
+		return 0;
+
+	BUG_ON(pcol->ios);
+	ret = ore_get_rw_state(&pcol->sbi->layout, &oi->oc, false,
+				 pcol->pg_first << PAGE_CACHE_SHIFT,
+				 pcol->length, &pcol->ios);
+	if (unlikely(ret))
+		goto err;
+
+	pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
+	if (!pcol_copy) {
+		EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	*pcol_copy = *pcol;
+
+	ios = pcol->ios;
+	ios->pages = pcol_copy->pages;
+	ios->done = writepages_done;
+	ios->r4w = &_r4w_op;
+	ios->private = pcol_copy;
+
+	/* pages ownership was passed to pcol_copy */
+	_pcol_reset(pcol);
+
+	ret = _maybe_not_all_in_one_io(ios, pcol_copy, pcol);
+	if (unlikely(ret))
+		goto err;
+
+	EXOFS_DBGMSG2("write_exec(0x%lx) offset=0x%llx length=0x%llx\n",
+		pcol->inode->i_ino, _LLU(ios->offset), _LLU(ios->length));
+
+	ret = ore_write(ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("write_exec: ore_write() Failed\n");
+		goto err;
+	}
+
+	atomic_inc(&pcol->sbi->s_curr_pending);
+	return 0;
+
+err:
+	if (!pcol_copy) /* Failed before ownership transfer */
+		pcol_copy = pcol;
+	_unlock_pcol_pages(pcol_copy, ret, WRITE);
+	pcol_free(pcol_copy);
+	kfree(pcol_copy);
+
+	return ret;
+}
+
+/* writepage_strip is called either directly from writepage() or by the VFS from
+ * within write_cache_pages(), to add one more page to be written to storage.
+ * It will try to collect as many contiguous pages as possible. If a
+ * discontinuity is encountered or it runs out of resources it will submit the
+ * previous segment and will start a new collection.
+ * Eventually caller must submit the last segment if present.
+ */
+static int writepage_strip(struct page *page,
+			   struct writeback_control *wbc_unused, void *data)
+{
+	struct page_collect *pcol = data;
+	struct inode *inode = pcol->inode;
+	struct exofs_i_info *oi = exofs_i(inode);
+	loff_t i_size = i_size_read(inode);
+	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	size_t len;
+	int ret;
+
+	BUG_ON(!PageLocked(page));
+
+	ret = wait_obj_created(oi);
+	if (unlikely(ret))
+		goto fail;
+
+	if (page->index < end_index)
+		/* in this case, the page is within the limits of the file */
+		len = PAGE_CACHE_SIZE;
+	else {
+		len = i_size & ~PAGE_CACHE_MASK;
+
+		if (page->index > end_index || !len) {
+			/* in this case, the page is outside the limits
+			 * (truncate in progress)
+			 */
+			ret = write_exec(pcol);
+			if (unlikely(ret))
+				goto fail;
+			if (PageError(page))
+				ClearPageError(page);
+			unlock_page(page);
+			EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
+				     "outside the limits\n",
+				     inode->i_ino, page->index);
+			return 0;
+		}
+	}
+
+try_again:
+
+	if (unlikely(pcol->pg_first == -1)) {
+		pcol->pg_first = page->index;
+	} else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
+		   page->index)) {
+		/* Discontinuity detected, split the request */
+		ret = write_exec(pcol);
+		if (unlikely(ret))
+			goto fail;
+
+		EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
+			     inode->i_ino, page->index);
+		goto try_again;
+	}
+
+	if (!pcol->pages) {
+		ret = pcol_try_alloc(pcol);
+		if (unlikely(ret))
+			goto fail;
+	}
+
+	EXOFS_DBGMSG2("    writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
+		     inode->i_ino, page->index, len);
+
+	ret = pcol_add_page(pcol, page, len);
+	if (unlikely(ret)) {
+		EXOFS_DBGMSG2("Failed pcol_add_page "
+			     "nr_pages=%u total_length=0x%lx\n",
+			     pcol->nr_pages, pcol->length);
+
+		/* split the request, next loop will start again */
+		ret = write_exec(pcol);
+		if (unlikely(ret)) {
+			EXOFS_DBGMSG("write_exec failed => %d", ret);
+			goto fail;
+		}
+
+		goto try_again;
+	}
+
+	BUG_ON(PageWriteback(page));
+	set_page_writeback(page);
+
+	return 0;
+
+fail:
+	EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
+		     inode->i_ino, page->index, ret);
+	set_bit(AS_EIO, &page->mapping->flags);
+	unlock_page(page);
+	return ret;
+}
+
+static int exofs_writepages(struct address_space *mapping,
+		       struct writeback_control *wbc)
+{
+	struct page_collect pcol;
+	long start, end, expected_pages;
+	int ret;
+
+	start = wbc->range_start >> PAGE_CACHE_SHIFT;
+	end = (wbc->range_end == LLONG_MAX) ?
+			start + mapping->nrpages :
+			wbc->range_end >> PAGE_CACHE_SHIFT;
+
+	if (start || end)
+		expected_pages = end - start + 1;
+	else
+		expected_pages = mapping->nrpages;
+
+	if (expected_pages < 32L)
+		expected_pages = 32L;
+
+	EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
+		     "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
+		     mapping->host->i_ino, wbc->range_start, wbc->range_end,
+		     mapping->nrpages, start, end, expected_pages);
+
+	_pcol_init(&pcol, expected_pages, mapping->host);
+
+	ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
+	if (unlikely(ret)) {
+		EXOFS_ERR("write_cache_pages => %d\n", ret);
+		return ret;
+	}
+
+	ret = write_exec(&pcol);
+	if (unlikely(ret))
+		return ret;
+
+	if (wbc->sync_mode == WB_SYNC_ALL) {
+		return write_exec(&pcol); /* pump the last reminder */
+	} else if (pcol.nr_pages) {
+		/* not SYNC let the reminder join the next writeout */
+		unsigned i;
+
+		for (i = 0; i < pcol.nr_pages; i++) {
+			struct page *page = pcol.pages[i];
+
+			end_page_writeback(page);
+			set_page_dirty(page);
+			unlock_page(page);
+		}
+	}
+	return 0;
+}
+
+/*
+static int exofs_writepage(struct page *page, struct writeback_control *wbc)
+{
+	struct page_collect pcol;
+	int ret;
+
+	_pcol_init(&pcol, 1, page->mapping->host);
+
+	ret = writepage_strip(page, NULL, &pcol);
+	if (ret) {
+		EXOFS_ERR("exofs_writepage => %d\n", ret);
+		return ret;
+	}
+
+	return write_exec(&pcol);
+}
+*/
+/* i_mutex held using inode->i_size directly */
+static void _write_failed(struct inode *inode, loff_t to)
+{
+	if (to > inode->i_size)
+		truncate_pagecache(inode, inode->i_size);
+}
+
+int exofs_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
+{
+	int ret = 0;
+	struct page *page;
+
+	page = *pagep;
+	if (page == NULL) {
+		ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
+					 fsdata);
+		if (ret) {
+			EXOFS_DBGMSG("simple_write_begin failed\n");
+			goto out;
+		}
+
+		page = *pagep;
+	}
+
+	 /* read modify write */
+	if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
+		loff_t i_size = i_size_read(mapping->host);
+		pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+		size_t rlen;
+
+		if (page->index < end_index)
+			rlen = PAGE_CACHE_SIZE;
+		else if (page->index == end_index)
+			rlen = i_size & ~PAGE_CACHE_MASK;
+		else
+			rlen = 0;
+
+		if (!rlen) {
+			clear_highpage(page);
+			SetPageUptodate(page);
+			goto out;
+		}
+
+		ret = _readpage(page, true);
+		if (ret) {
+			/*SetPageError was done by _readpage. Is it ok?*/
+			unlock_page(page);
+			EXOFS_DBGMSG("__readpage failed\n");
+		}
+	}
+out:
+	if (unlikely(ret))
+		_write_failed(mapping->host, pos + len);
+
+	return ret;
+}
+
+static int exofs_write_begin_export(struct file *file,
+		struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
+{
+	*pagep = NULL;
+
+	return exofs_write_begin(file, mapping, pos, len, flags, pagep,
+					fsdata);
+}
+
+static int exofs_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	struct inode *inode = mapping->host;
+	/* According to comment in simple_write_end i_mutex is held */
+	loff_t i_size = inode->i_size;
+	int ret;
+
+	ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
+	if (unlikely(ret))
+		_write_failed(inode, pos + len);
+
+	/* TODO: once simple_write_end marks inode dirty remove */
+	if (i_size != inode->i_size)
+		mark_inode_dirty(inode);
+	return ret;
+}
+
+static int exofs_releasepage(struct page *page, gfp_t gfp)
+{
+	EXOFS_DBGMSG("page 0x%lx\n", page->index);
+	WARN_ON(1);
+	return 0;
+}
+
+static void exofs_invalidatepage(struct page *page, unsigned int offset,
+				 unsigned int length)
+{
+	EXOFS_DBGMSG("page 0x%lx offset 0x%x length 0x%x\n",
+		     page->index, offset, length);
+	WARN_ON(1);
+}
+
+
+ /* TODO: Should be easy enough to do proprly */
+static ssize_t exofs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+			       loff_t offset)
+{
+	return 0;
+}
+
+const struct address_space_operations exofs_aops = {
+	.readpage	= exofs_readpage,
+	.readpages	= exofs_readpages,
+	.writepage	= NULL,
+	.writepages	= exofs_writepages,
+	.write_begin	= exofs_write_begin_export,
+	.write_end	= exofs_write_end,
+	.releasepage	= exofs_releasepage,
+	.set_page_dirty	= __set_page_dirty_nobuffers,
+	.invalidatepage = exofs_invalidatepage,
+
+	/* Not implemented Yet */
+	.bmap		= NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
+	.direct_IO	= exofs_direct_IO,
+
+	/* With these NULL has special meaning or default is not exported */
+	.migratepage	= NULL,
+	.launder_page	= NULL,
+	.is_partially_uptodate = NULL,
+	.error_remove_page = NULL,
+};
+
+/******************************************************************************
+ * INODE OPERATIONS
+ *****************************************************************************/
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int exofs_inode_is_fast_symlink(struct inode *inode)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+
+	return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
+}
+
+static int _do_truncate(struct inode *inode, loff_t newsize)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+	int ret;
+
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+
+	ret = ore_truncate(&sbi->layout, &oi->oc, (u64)newsize);
+	if (likely(!ret))
+		truncate_setsize(inode, newsize);
+
+	EXOFS_DBGMSG2("(0x%lx) size=0x%llx ret=>%d\n",
+		     inode->i_ino, newsize, ret);
+	return ret;
+}
+
+/*
+ * Set inode attributes - update size attribute on OSD if needed,
+ *                        otherwise just call generic functions.
+ */
+int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	struct inode *inode = d_inode(dentry);
+	int error;
+
+	/* if we are about to modify an object, and it hasn't been
+	 * created yet, wait
+	 */
+	error = wait_obj_created(exofs_i(inode));
+	if (unlikely(error))
+		return error;
+
+	error = inode_change_ok(inode, iattr);
+	if (unlikely(error))
+		return error;
+
+	if ((iattr->ia_valid & ATTR_SIZE) &&
+	    iattr->ia_size != i_size_read(inode)) {
+		error = _do_truncate(inode, iattr->ia_size);
+		if (unlikely(error))
+			return error;
+	}
+
+	setattr_copy(inode, iattr);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
+	EXOFS_APAGE_FS_DATA,
+	EXOFS_ATTR_INODE_FILE_LAYOUT,
+	0);
+static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
+	EXOFS_APAGE_FS_DATA,
+	EXOFS_ATTR_INODE_DIR_LAYOUT,
+	0);
+
+/*
+ * Read the Linux inode info from the OSD, and return it as is. In exofs the
+ * inode info is in an application specific page/attribute of the osd-object.
+ */
+static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
+		    struct exofs_fcb *inode)
+{
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct osd_attr attrs[] = {
+		[0] = g_attr_inode_data,
+		[1] = g_attr_inode_file_layout,
+		[2] = g_attr_inode_dir_layout,
+	};
+	struct ore_io_state *ios;
+	struct exofs_on_disk_inode_layout *layout;
+	int ret;
+
+	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
+		return ret;
+	}
+
+	attrs[1].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
+	attrs[2].len = exofs_on_disk_inode_layout_size(sbi->oc.numdevs);
+
+	ios->in_attr = attrs;
+	ios->in_attr_len = ARRAY_SIZE(attrs);
+
+	ret = ore_read(ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
+			  _LLU(oi->one_comp.obj.id), ret);
+		memset(inode, 0, sizeof(*inode));
+		inode->i_mode = 0040000 | (0777 & ~022);
+		/* If object is lost on target we might as well enable it's
+		 * delete.
+		 */
+		ret = 0;
+		goto out;
+	}
+
+	ret = extract_attr_from_ios(ios, &attrs[0]);
+	if (ret) {
+		EXOFS_ERR("%s: extract_attr 0 of inode failed\n", __func__);
+		goto out;
+	}
+	WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
+	memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
+
+	ret = extract_attr_from_ios(ios, &attrs[1]);
+	if (ret) {
+		EXOFS_ERR("%s: extract_attr 1 of inode failed\n", __func__);
+		goto out;
+	}
+	if (attrs[1].len) {
+		layout = attrs[1].val_ptr;
+		if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
+			EXOFS_ERR("%s: unsupported files layout %d\n",
+				__func__, layout->gen_func);
+			ret = -ENOTSUPP;
+			goto out;
+		}
+	}
+
+	ret = extract_attr_from_ios(ios, &attrs[2]);
+	if (ret) {
+		EXOFS_ERR("%s: extract_attr 2 of inode failed\n", __func__);
+		goto out;
+	}
+	if (attrs[2].len) {
+		layout = attrs[2].val_ptr;
+		if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
+			EXOFS_ERR("%s: unsupported meta-data layout %d\n",
+				__func__, layout->gen_func);
+			ret = -ENOTSUPP;
+			goto out;
+		}
+	}
+
+out:
+	ore_put_io_state(ios);
+	return ret;
+}
+
+static void __oi_init(struct exofs_i_info *oi)
+{
+	init_waitqueue_head(&oi->i_wq);
+	oi->i_flags = 0;
+}
+/*
+ * Fill in an inode read from the OSD and set it up for use
+ */
+struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct exofs_i_info *oi;
+	struct exofs_fcb fcb;
+	struct inode *inode;
+	int ret;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+	oi = exofs_i(inode);
+	__oi_init(oi);
+	exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
+			 exofs_oi_objno(oi));
+
+	/* read the inode from the osd */
+	ret = exofs_get_inode(sb, oi, &fcb);
+	if (ret)
+		goto bad_inode;
+
+	set_obj_created(oi);
+
+	/* copy stuff from on-disk struct to in-memory struct */
+	inode->i_mode = le16_to_cpu(fcb.i_mode);
+	i_uid_write(inode, le32_to_cpu(fcb.i_uid));
+	i_gid_write(inode, le32_to_cpu(fcb.i_gid));
+	set_nlink(inode, le16_to_cpu(fcb.i_links_count));
+	inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
+	inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
+	inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
+	inode->i_ctime.tv_nsec =
+		inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
+	oi->i_commit_size = le64_to_cpu(fcb.i_size);
+	i_size_write(inode, oi->i_commit_size);
+	inode->i_blkbits = EXOFS_BLKSHIFT;
+	inode->i_generation = le32_to_cpu(fcb.i_generation);
+
+	oi->i_dir_start_lookup = 0;
+
+	if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
+		ret = -ESTALE;
+		goto bad_inode;
+	}
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (fcb.i_data[0])
+			inode->i_rdev =
+				old_decode_dev(le32_to_cpu(fcb.i_data[0]));
+		else
+			inode->i_rdev =
+				new_decode_dev(le32_to_cpu(fcb.i_data[1]));
+	} else {
+		memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
+	}
+
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &exofs_file_inode_operations;
+		inode->i_fop = &exofs_file_operations;
+		inode->i_mapping->a_ops = &exofs_aops;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &exofs_dir_inode_operations;
+		inode->i_fop = &exofs_dir_operations;
+		inode->i_mapping->a_ops = &exofs_aops;
+	} else if (S_ISLNK(inode->i_mode)) {
+		if (exofs_inode_is_fast_symlink(inode))
+			inode->i_op = &exofs_fast_symlink_inode_operations;
+		else {
+			inode->i_op = &exofs_symlink_inode_operations;
+			inode->i_mapping->a_ops = &exofs_aops;
+		}
+	} else {
+		inode->i_op = &exofs_special_inode_operations;
+		if (fcb.i_data[0])
+			init_special_inode(inode, inode->i_mode,
+			   old_decode_dev(le32_to_cpu(fcb.i_data[0])));
+		else
+			init_special_inode(inode, inode->i_mode,
+			   new_decode_dev(le32_to_cpu(fcb.i_data[1])));
+	}
+
+	unlock_new_inode(inode);
+	return inode;
+
+bad_inode:
+	iget_failed(inode);
+	return ERR_PTR(ret);
+}
+
+int __exofs_wait_obj_created(struct exofs_i_info *oi)
+{
+	if (!obj_created(oi)) {
+		EXOFS_DBGMSG("!obj_created\n");
+		BUG_ON(!obj_2bcreated(oi));
+		wait_event(oi->i_wq, obj_created(oi));
+		EXOFS_DBGMSG("wait_event done\n");
+	}
+	return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
+}
+
+/*
+ * Callback function from exofs_new_inode().  The important thing is that we
+ * set the obj_created flag so that other methods know that the object exists on
+ * the OSD.
+ */
+static void create_done(struct ore_io_state *ios, void *p)
+{
+	struct inode *inode = p;
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+	int ret;
+
+	ret = ore_check_io(ios, NULL);
+	ore_put_io_state(ios);
+
+	atomic_dec(&sbi->s_curr_pending);
+
+	if (unlikely(ret)) {
+		EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
+			  _LLU(exofs_oi_objno(oi)),
+			  _LLU(oi->one_comp.obj.partition));
+		/*TODO: When FS is corrupted creation can fail, object already
+		 * exist. Get rid of this asynchronous creation, if exist
+		 * increment the obj counter and try the next object. Until we
+		 * succeed. All these dangling objects will be made into lost
+		 * files by chkfs.exofs
+		 */
+	}
+
+	set_obj_created(oi);
+
+	wake_up(&oi->i_wq);
+}
+
+/*
+ * Set up a new inode and create an object for it on the OSD
+ */
+struct inode *exofs_new_inode(struct inode *dir, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct inode *inode;
+	struct exofs_i_info *oi;
+	struct ore_io_state *ios;
+	int ret;
+
+	inode = new_inode(sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	oi = exofs_i(inode);
+	__oi_init(oi);
+
+	set_obj_2bcreated(oi);
+
+	inode_init_owner(inode, dir, mode);
+	inode->i_ino = sbi->s_nextid++;
+	inode->i_blkbits = EXOFS_BLKSHIFT;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	oi->i_commit_size = inode->i_size = 0;
+	spin_lock(&sbi->s_next_gen_lock);
+	inode->i_generation = sbi->s_next_generation++;
+	spin_unlock(&sbi->s_next_gen_lock);
+	insert_inode_hash(inode);
+
+	exofs_init_comps(&oi->oc, &oi->one_comp, sb->s_fs_info,
+			 exofs_oi_objno(oi));
+	exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
+
+	mark_inode_dirty(inode);
+
+	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("exofs_new_inode: ore_get_io_state failed\n");
+		return ERR_PTR(ret);
+	}
+
+	ios->done = create_done;
+	ios->private = inode;
+
+	ret = ore_create(ios);
+	if (ret) {
+		ore_put_io_state(ios);
+		return ERR_PTR(ret);
+	}
+	atomic_inc(&sbi->s_curr_pending);
+
+	return inode;
+}
+
+/*
+ * struct to pass two arguments to update_inode's callback
+ */
+struct updatei_args {
+	struct exofs_sb_info	*sbi;
+	struct exofs_fcb	fcb;
+};
+
+/*
+ * Callback function from exofs_update_inode().
+ */
+static void updatei_done(struct ore_io_state *ios, void *p)
+{
+	struct updatei_args *args = p;
+
+	ore_put_io_state(ios);
+
+	atomic_dec(&args->sbi->s_curr_pending);
+
+	kfree(args);
+}
+
+/*
+ * Write the inode to the OSD.  Just fill up the struct, and set the attribute
+ * synchronously or asynchronously depending on the do_sync flag.
+ */
+static int exofs_update_inode(struct inode *inode, int do_sync)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct ore_io_state *ios;
+	struct osd_attr attr;
+	struct exofs_fcb *fcb;
+	struct updatei_args *args;
+	int ret;
+
+	args = kzalloc(sizeof(*args), GFP_KERNEL);
+	if (!args) {
+		EXOFS_DBGMSG("Failed kzalloc of args\n");
+		return -ENOMEM;
+	}
+
+	fcb = &args->fcb;
+
+	fcb->i_mode = cpu_to_le16(inode->i_mode);
+	fcb->i_uid = cpu_to_le32(i_uid_read(inode));
+	fcb->i_gid = cpu_to_le32(i_gid_read(inode));
+	fcb->i_links_count = cpu_to_le16(inode->i_nlink);
+	fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+	fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+	fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+	oi->i_commit_size = i_size_read(inode);
+	fcb->i_size = cpu_to_le64(oi->i_commit_size);
+	fcb->i_generation = cpu_to_le32(inode->i_generation);
+
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (old_valid_dev(inode->i_rdev)) {
+			fcb->i_data[0] =
+				cpu_to_le32(old_encode_dev(inode->i_rdev));
+			fcb->i_data[1] = 0;
+		} else {
+			fcb->i_data[0] = 0;
+			fcb->i_data[1] =
+				cpu_to_le32(new_encode_dev(inode->i_rdev));
+			fcb->i_data[2] = 0;
+		}
+	} else
+		memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
+
+	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
+		goto free_args;
+	}
+
+	attr = g_attr_inode_data;
+	attr.val_ptr = fcb;
+	ios->out_attr_len = 1;
+	ios->out_attr = &attr;
+
+	wait_obj_created(oi);
+
+	if (!do_sync) {
+		args->sbi = sbi;
+		ios->done = updatei_done;
+		ios->private = args;
+	}
+
+	ret = ore_write(ios);
+	if (!do_sync && !ret) {
+		atomic_inc(&sbi->s_curr_pending);
+		goto out; /* deallocation in updatei_done */
+	}
+
+	ore_put_io_state(ios);
+free_args:
+	kfree(args);
+out:
+	EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
+		     inode->i_ino, do_sync, ret);
+	return ret;
+}
+
+int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	/* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
+	return exofs_update_inode(inode, 1);
+}
+
+/*
+ * Callback function from exofs_delete_inode() - don't have much cleaning up to
+ * do.
+ */
+static void delete_done(struct ore_io_state *ios, void *p)
+{
+	struct exofs_sb_info *sbi = p;
+
+	ore_put_io_state(ios);
+
+	atomic_dec(&sbi->s_curr_pending);
+}
+
+/*
+ * Called when the refcount of an inode reaches zero.  We remove the object
+ * from the OSD here.  We make sure the object was created before we try and
+ * delete it.
+ */
+void exofs_evict_inode(struct inode *inode)
+{
+	struct exofs_i_info *oi = exofs_i(inode);
+	struct super_block *sb = inode->i_sb;
+	struct exofs_sb_info *sbi = sb->s_fs_info;
+	struct ore_io_state *ios;
+	int ret;
+
+	truncate_inode_pages_final(&inode->i_data);
+
+	/* TODO: should do better here */
+	if (inode->i_nlink || is_bad_inode(inode))
+		goto no_delete;
+
+	inode->i_size = 0;
+	clear_inode(inode);
+
+	/* if we are deleting an obj that hasn't been created yet, wait.
+	 * This also makes sure that create_done cannot be called with an
+	 * already evicted inode.
+	 */
+	wait_obj_created(oi);
+	/* ignore the error, attempt a remove anyway */
+
+	/* Now Remove the OSD objects */
+	ret = ore_get_io_state(&sbi->layout, &oi->oc, &ios);
+	if (unlikely(ret)) {
+		EXOFS_ERR("%s: ore_get_io_state failed\n", __func__);
+		return;
+	}
+
+	ios->done = delete_done;
+	ios->private = sbi;
+
+	ret = ore_remove(ios);
+	if (ret) {
+		EXOFS_ERR("%s: ore_remove failed\n", __func__);
+		ore_put_io_state(ios);
+		return;
+	}
+	atomic_inc(&sbi->s_curr_pending);
+
+	return;
+
+no_delete:
+	clear_inode(inode);
+}