Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  fs: Add exofs to Kernel build
  exofs: Documentation
  exofs: export_operations
  exofs: super_operations and file_system_type
  exofs: dir_inode and directory operations
  exofs: address_space_operations
  exofs: symlink_inode and fast_symlink_inode operations
  exofs: file and file_inode operations
  exofs: Kbuild, Headers and osd utils

14 files changed, 3597 insertions, 0 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index cef8b18ceaa..ae3b34a2ea6 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -169,6 +169,8 @@ source "fs/romfs/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
 
+source "fs/exofs/Kconfig"
+
 endif # MISC_FILESYSTEMS
 
 menuconfig NETWORK_FILESYSTEMS
diff --git a/fs/Makefile b/fs/Makefile
index b5cd8e18dd9..15f73014a20 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -120,3 +120,4 @@ obj-$(CONFIG_DEBUG_FS)		+= debugfs/
 obj-$(CONFIG_OCFS2_FS)		+= ocfs2/
 obj-$(CONFIG_BTRFS_FS)		+= btrfs/
 obj-$(CONFIG_GFS2_FS)           += gfs2/
+obj-$(CONFIG_EXOFS_FS)          += exofs/
diff --git a/fs/exofs/BUGS b/fs/exofs/BUGS
new file mode 100644
index 00000000000..1b2d4c63a57
--- /dev/null
+++ b/fs/exofs/BUGS
@@ -0,0 +1,3 @@
+- Out-of-space may cause a severe problem if the object (and directory entry)
+  were written, but the inode attributes failed. Then if the filesystem was
+  unmounted and mounted the kernel can get into an endless loop doing a readdir.
diff --git a/fs/exofs/Kbuild b/fs/exofs/Kbuild
new file mode 100644
index 00000000000..cc2d22db119
--- /dev/null
+++ b/fs/exofs/Kbuild
@@ -0,0 +1,16 @@
+#
+# Kbuild for the EXOFS module
+#
+# Copyright (C) 2008 Panasas Inc.  All rights reserved.
+#
+# Authors:
+#   Boaz Harrosh <bharrosh@panasas.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2
+#
+# Kbuild - Gets included from the Kernels Makefile and build system
+#
+
+exofs-y := osd.o inode.o file.o symlink.o namei.o dir.o super.o
+obj-$(CONFIG_EXOFS_FS) += exofs.o
diff --git a/fs/exofs/Kconfig b/fs/exofs/Kconfig
new file mode 100644
index 00000000000..86194b2f799
--- /dev/null
+++ b/fs/exofs/Kconfig
@@ -0,0 +1,13 @@
+config EXOFS_FS
+	tristate "exofs: OSD based file system support"
+	depends on SCSI_OSD_ULD
+	help
+	  EXOFS is a file system that uses an OSD storage device,
+	  as its backing storage.
+
+# Debugging-related stuff
+config EXOFS_DEBUG
+	bool "Enable debugging"
+	depends on EXOFS_FS
+	help
+	  This option enables EXOFS debug prints.
diff --git a/fs/exofs/common.h b/fs/exofs/common.h
new file mode 100644
index 00000000000..b1512c4bb8c
--- /dev/null
+++ b/fs/exofs/common.h
@@ -0,0 +1,184 @@
+/*
+ * common.h - Common definitions for both Kernel and user-mode utilities
+ *
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
+ * Copyright (C) 2005, 2006
+ * International Business Machines
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <bharrosh@panasas.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
+ */
+
+#ifndef __EXOFS_COM_H__
+#define __EXOFS_COM_H__
+
+#include <linux/types.h>
+
+#include <scsi/osd_attributes.h>
+#include <scsi/osd_initiator.h>
+#include <scsi/osd_sec.h>
+
+/****************************************************************************
+ * Object ID related defines
+ * NOTE: inode# = object ID - EXOFS_OBJ_OFF
+ ****************************************************************************/
+#define EXOFS_MIN_PID   0x10000	/* Smallest partition ID */
+#define EXOFS_OBJ_OFF	0x10000	/* offset for objects */
+#define EXOFS_SUPER_ID	0x10000	/* object ID for on-disk superblock */
+#define EXOFS_ROOT_ID	0x10002	/* object ID for root directory */
+
+/* exofs Application specific page/attribute */
+# define EXOFS_APAGE_FS_DATA	(OSD_APAGE_APP_DEFINED_FIRST + 3)
+# define EXOFS_ATTR_INODE_DATA	1
+
+/*
+ * The maximum number of files we can have is limited by the size of the
+ * inode number.  This is the largest object ID that the file system supports.
+ * Object IDs 0, 1, and 2 are always in use (see above defines).
+ */
+enum {
+	EXOFS_MAX_INO_ID = (sizeof(ino_t) * 8 == 64) ? ULLONG_MAX :
+					(1ULL << (sizeof(ino_t) * 8ULL - 1ULL)),
+	EXOFS_MAX_ID	 = (EXOFS_MAX_INO_ID - 1 - EXOFS_OBJ_OFF),
+};
+
+/****************************************************************************
+ * Misc.
+ ****************************************************************************/
+#define EXOFS_BLKSHIFT	12
+#define EXOFS_BLKSIZE	(1UL << EXOFS_BLKSHIFT)
+
+/****************************************************************************
+ * superblock-related things
+ ****************************************************************************/
+#define EXOFS_SUPER_MAGIC	0x5DF5
+
+/*
+ * The file system control block - stored in an object's data (mainly, the one
+ * with ID EXOFS_SUPER_ID).  This is where the in-memory superblock is stored
+ * on disk.  Right now it just has a magic value, which is basically a sanity
+ * check on our ability to communicate with the object store.
+ */
+struct exofs_fscb {
+	__le64  s_nextid;	/* Highest object ID used */
+	__le32  s_numfiles;	/* Number of files on fs */
+	__le16  s_magic;	/* Magic signature */
+	__le16  s_newfs;	/* Non-zero if this is a new fs */
+};
+
+/****************************************************************************
+ * inode-related things
+ ****************************************************************************/
+#define EXOFS_IDATA		5
+
+/*
+ * The file control block - stored in an object's attributes.  This is where
+ * the in-memory inode is stored on disk.
+ */
+struct exofs_fcb {
+	__le64  i_size;			/* Size of the file */
+	__le16  i_mode;         	/* File mode */
+	__le16  i_links_count;  	/* Links count */
+	__le32  i_uid;          	/* Owner Uid */
+	__le32  i_gid;          	/* Group Id */
+	__le32  i_atime;        	/* Access time */
+	__le32  i_ctime;        	/* Creation time */
+	__le32  i_mtime;        	/* Modification time */
+	__le32  i_flags;        	/* File flags (unused for now)*/
+	__le32  i_generation;   	/* File version (for NFS) */
+	__le32  i_data[EXOFS_IDATA];	/* Short symlink names and device #s */
+};
+
+#define EXOFS_INO_ATTR_SIZE	sizeof(struct exofs_fcb)
+
+/* This is the Attribute the fcb is stored in */
+static const struct __weak osd_attr g_attr_inode_data = ATTR_DEF(
+	EXOFS_APAGE_FS_DATA,
+	EXOFS_ATTR_INODE_DATA,
+	EXOFS_INO_ATTR_SIZE);
+
+/****************************************************************************
+ * dentry-related things
+ ****************************************************************************/
+#define EXOFS_NAME_LEN	255
+
+/*
+ * The on-disk directory entry
+ */
+struct exofs_dir_entry {
+	__le64		inode_no;		/* inode number           */
+	__le16		rec_len;		/* directory entry length */
+	u8		name_len;		/* name length            */
+	u8		file_type;		/* umm...file type        */
+	char		name[EXOFS_NAME_LEN];	/* file name              */
+};
+
+enum {
+	EXOFS_FT_UNKNOWN,
+	EXOFS_FT_REG_FILE,
+	EXOFS_FT_DIR,
+	EXOFS_FT_CHRDEV,
+	EXOFS_FT_BLKDEV,
+	EXOFS_FT_FIFO,
+	EXOFS_FT_SOCK,
+	EXOFS_FT_SYMLINK,
+	EXOFS_FT_MAX
+};
+
+#define EXOFS_DIR_PAD			4
+#define EXOFS_DIR_ROUND			(EXOFS_DIR_PAD - 1)
+#define EXOFS_DIR_REC_LEN(name_len) \
+	(((name_len) + offsetof(struct exofs_dir_entry, name)  + \
+	  EXOFS_DIR_ROUND) & ~EXOFS_DIR_ROUND)
+
+/*************************
+ * function declarations *
+ *************************/
+/* osd.c                 */
+void exofs_make_credential(u8 cred_a[OSD_CAP_LEN],
+			   const struct osd_obj_id *obj);
+
+int exofs_check_ok_resid(struct osd_request *or, u64 *in_resid, u64 *out_resid);
+static inline int exofs_check_ok(struct osd_request *or)
+{
+	return exofs_check_ok_resid(or, NULL, NULL);
+}
+int exofs_sync_op(struct osd_request *or, int timeout, u8 *cred);
+int exofs_async_op(struct osd_request *or,
+	osd_req_done_fn *async_done, void *caller_context, u8 *cred);
+
+int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr);
+
+int osd_req_read_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void *buff, u64 len);
+
+int osd_req_write_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void *buff, u64 len);
+
+#endif /*ifndef __EXOFS_COM_H__*/
diff --git a/fs/exofs/dir.c b/fs/exofs/dir.c
new file mode 100644
index 00000000000..65b0c8c776a
--- /dev/null
+++ b/fs/exofs/dir.c
@@ -0,0 +1,672 @@
+/*
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
+ * Copyright (C) 2005, 2006
+ * International Business Machines
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <bharrosh@panasas.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 "exofs.h"
+
+static inline unsigned exofs_chunk_size(struct inode *inode)
+{
+	return inode->i_sb->s_blocksize;
+}
+
+static inline void exofs_put_page(struct page *page)
+{
+	kunmap(page);
+	page_cache_release(page);
+}
+
+/* Accesses dir's inode->i_size must be called under inode lock */
+static inline unsigned long dir_pages(struct inode *inode)
+{
+	return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+}
+
+static unsigned exofs_last_byte(struct inode *inode, unsigned long page_nr)
+{
+	loff_t last_byte = inode->i_size;
+
+	last_byte -= page_nr << PAGE_CACHE_SHIFT;
+	if (last_byte > PAGE_CACHE_SIZE)
+		last_byte = PAGE_CACHE_SIZE;
+	return last_byte;
+}
+
+static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *dir = mapping->host;
+	int err = 0;
+
+	dir->i_version++;
+
+	if (!PageUptodate(page))
+		SetPageUptodate(page);
+
+	if (pos+len > dir->i_size) {
+		i_size_write(dir, pos+len);
+		mark_inode_dirty(dir);
+	}
+	set_page_dirty(page);
+
+	if (IS_DIRSYNC(dir))
+		err = write_one_page(page, 1);
+	else
+		unlock_page(page);
+
+	return err;
+}
+
+static void exofs_check_page(struct page *page)
+{
+	struct inode *dir = page->mapping->host;
+	unsigned chunk_size = exofs_chunk_size(dir);
+	char *kaddr = page_address(page);
+	unsigned offs, rec_len;
+	unsigned limit = PAGE_CACHE_SIZE;
+	struct exofs_dir_entry *p;
+	char *error;
+
+	/* if the page is the last one in the directory */
+	if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
+		limit = dir->i_size & ~PAGE_CACHE_MASK;
+		if (limit & (chunk_size - 1))
+			goto Ebadsize;
+		if (!limit)
+			goto out;
+	}
+	for (offs = 0; offs <= limit - EXOFS_DIR_REC_LEN(1); offs += rec_len) {
+		p = (struct exofs_dir_entry *)(kaddr + offs);
+		rec_len = le16_to_cpu(p->rec_len);
+
+		if (rec_len < EXOFS_DIR_REC_LEN(1))
+			goto Eshort;
+		if (rec_len & 3)
+			goto Ealign;
+		if (rec_len < EXOFS_DIR_REC_LEN(p->name_len))
+			goto Enamelen;
+		if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1))
+			goto Espan;
+	}
+	if (offs != limit)
+		goto Eend;
+out:
+	SetPageChecked(page);
+	return;
+
+Ebadsize:
+	EXOFS_ERR("ERROR [exofs_check_page]: "
+		"size of directory #%lu is not a multiple of chunk size",
+		dir->i_ino
+	);
+	goto fail;
+Eshort:
+	error = "rec_len is smaller than minimal";
+	goto bad_entry;
+Ealign:
+	error = "unaligned directory entry";
+	goto bad_entry;
+Enamelen:
+	error = "rec_len is too small for name_len";
+	goto bad_entry;
+Espan:
+	error = "directory entry across blocks";
+	goto bad_entry;
+bad_entry:
+	EXOFS_ERR(
+		"ERROR [exofs_check_page]: bad entry in directory #%lu: %s - "
+		"offset=%lu, inode=%llu, rec_len=%d, name_len=%d",
+		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+		_LLU(le64_to_cpu(p->inode_no)),
+		rec_len, p->name_len);
+	goto fail;
+Eend:
+	p = (struct exofs_dir_entry *)(kaddr + offs);
+	EXOFS_ERR("ERROR [exofs_check_page]: "
+		"entry in directory #%lu spans the page boundary"
+		"offset=%lu, inode=%llu",
+		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+		_LLU(le64_to_cpu(p->inode_no)));
+fail:
+	SetPageChecked(page);
+	SetPageError(page);
+}
+
+static struct page *exofs_get_page(struct inode *dir, unsigned long n)
+{
+	struct address_space *mapping = dir->i_mapping;
+	struct page *page = read_mapping_page(mapping, n, NULL);
+
+	if (!IS_ERR(page)) {
+		kmap(page);
+		if (!PageChecked(page))
+			exofs_check_page(page);
+		if (PageError(page))
+			goto fail;
+	}
+	return page;
+
+fail:
+	exofs_put_page(page);
+	return ERR_PTR(-EIO);
+}
+
+static inline int exofs_match(int len, const unsigned char *name,
+					struct exofs_dir_entry *de)
+{
+	if (len != de->name_len)
+		return 0;
+	if (!de->inode_no)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+static inline
+struct exofs_dir_entry *exofs_next_entry(struct exofs_dir_entry *p)
+{
+	return (struct exofs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len));
+}
+
+static inline unsigned
+exofs_validate_entry(char *base, unsigned offset, unsigned mask)
+{
+	struct exofs_dir_entry *de = (struct exofs_dir_entry *)(base + offset);
+	struct exofs_dir_entry *p =
+			(struct exofs_dir_entry *)(base + (offset&mask));
+	while ((char *)p < (char *)de) {
+		if (p->rec_len == 0)
+			break;
+		p = exofs_next_entry(p);
+	}
+	return (char *)p - base;
+}
+
+static unsigned char exofs_filetype_table[EXOFS_FT_MAX] = {
+	[EXOFS_FT_UNKNOWN]	= DT_UNKNOWN,
+	[EXOFS_FT_REG_FILE]	= DT_REG,
+	[EXOFS_FT_DIR]		= DT_DIR,
+	[EXOFS_FT_CHRDEV]	= DT_CHR,
+	[EXOFS_FT_BLKDEV]	= DT_BLK,
+	[EXOFS_FT_FIFO]		= DT_FIFO,
+	[EXOFS_FT_SOCK]		= DT_SOCK,
+	[EXOFS_FT_SYMLINK]	= DT_LNK,
+};
+
+#define S_SHIFT 12
+static unsigned char exofs_type_by_mode[S_IFMT >> S_SHIFT] = {
+	[S_IFREG >> S_SHIFT]	= EXOFS_FT_REG_FILE,
+	[S_IFDIR >> S_SHIFT]	= EXOFS_FT_DIR,
+	[S_IFCHR >> S_SHIFT]	= EXOFS_FT_CHRDEV,
+	[S_IFBLK >> S_SHIFT]	= EXOFS_FT_BLKDEV,
+	[S_IFIFO >> S_SHIFT]	= EXOFS_FT_FIFO,
+	[S_IFSOCK >> S_SHIFT]	= EXOFS_FT_SOCK,
+	[S_IFLNK >> S_SHIFT]	= EXOFS_FT_SYMLINK,
+};
+
+static inline
+void exofs_set_de_type(struct exofs_dir_entry *de, struct inode *inode)
+{
+	mode_t mode = inode->i_mode;
+	de->file_type = exofs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
+}
+
+static int
+exofs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	loff_t pos = filp->f_pos;
+	struct inode *inode = filp->f_path.dentry->d_inode;
+	unsigned int offset = pos & ~PAGE_CACHE_MASK;
+	unsigned long n = pos >> PAGE_CACHE_SHIFT;
+	unsigned long npages = dir_pages(inode);
+	unsigned chunk_mask = ~(exofs_chunk_size(inode)-1);
+	unsigned char *types = NULL;
+	int need_revalidate = (filp->f_version != inode->i_version);
+
+	if (pos > inode->i_size - EXOFS_DIR_REC_LEN(1))
+		return 0;
+
+	types = exofs_filetype_table;
+
+	for ( ; n < npages; n++, offset = 0) {
+		char *kaddr, *limit;
+		struct exofs_dir_entry *de;
+		struct page *page = exofs_get_page(inode, n);
+
+		if (IS_ERR(page)) {
+			EXOFS_ERR("ERROR: "
+				   "bad page in #%lu",
+				   inode->i_ino);
+			filp->f_pos += PAGE_CACHE_SIZE - offset;
+			return PTR_ERR(page);
+		}
+		kaddr = page_address(page);
+		if (unlikely(need_revalidate)) {
+			if (offset) {
+				offset = exofs_validate_entry(kaddr, offset,
+								chunk_mask);
+				filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
+			}
+			filp->f_version = inode->i_version;
+			need_revalidate = 0;
+		}
+		de = (struct exofs_dir_entry *)(kaddr + offset);
+		limit = kaddr + exofs_last_byte(inode, n) -
+							EXOFS_DIR_REC_LEN(1);
+		for (; (char *)de <= limit; de = exofs_next_entry(de)) {
+			if (de->rec_len == 0) {
+				EXOFS_ERR("ERROR: "
+					"zero-length directory entry");
+				exofs_put_page(page);
+				return -EIO;
+			}
+			if (de->inode_no) {
+				int over;
+				unsigned char d_type = DT_UNKNOWN;
+
+				if (types && de->file_type < EXOFS_FT_MAX)
+					d_type = types[de->file_type];
+
+				offset = (char *)de - kaddr;
+				over = filldir(dirent, de->name, de->name_len,
+						(n<<PAGE_CACHE_SHIFT) | offset,
+						le64_to_cpu(de->inode_no),
+						d_type);
+				if (over) {
+					exofs_put_page(page);
+					return 0;
+				}
+			}
+			filp->f_pos += le16_to_cpu(de->rec_len);
+		}
+		exofs_put_page(page);
+	}
+
+	return 0;
+}
+
+struct exofs_dir_entry *exofs_find_entry(struct inode *dir,
+			struct dentry *dentry, struct page **res_page)
+{
+	const unsigned char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	unsigned reclen = EXOFS_DIR_REC_LEN(namelen);
+	unsigned long start, n;
+	unsigned long npages = dir_pages(dir);
+	struct page *page = NULL;
+	struct exofs_i_info *oi = exofs_i(dir);
+	struct exofs_dir_entry *de;
+
+	if (npages == 0)
+		goto out;
+
+	*res_page = NULL;
+
+	start = oi->i_dir_start_lookup;
+	if (start >= npages)
+		start = 0;
+	n = start;
+	do {
+		char *kaddr;
+		page = exofs_get_page(dir, n);
+		if (!IS_ERR(page)) {
+			kaddr = page_address(page);
+			de = (struct exofs_dir_entry *) kaddr;
+			kaddr += exofs_last_byte(dir, n) - reclen;
+			while ((char *) de <= kaddr) {
+				if (de->rec_len == 0) {
+					EXOFS_ERR(
+						"ERROR: exofs_find_entry: "
+						"zero-length directory entry");
+					exofs_put_page(page);
+					goto out;
+				}
+				if (exofs_match(namelen, name, de))
+					goto found;
+				de = exofs_next_entry(de);
+			}
+			exofs_put_page(page);
+		}
+		if (++n >= npages)
+			n = 0;
+	} while (n != start);
+out:
+	return NULL;
+
+found:
+	*res_page = page;
+	oi->i_dir_start_lookup = n;
+	return de;
+}
+
+struct exofs_dir_entry *exofs_dotdot(struct inode *dir, struct page **p)
+{
+	struct page *page = exofs_get_page(dir, 0);
+	struct exofs_dir_entry *de = NULL;
+
+	if (!IS_ERR(page)) {
+		de = exofs_next_entry(
+				(struct exofs_dir_entry *)page_address(page));
+		*p = page;
+	}
+	return de;
+}
+
+ino_t exofs_parent_ino(struct dentry *child)
+{
+	struct page *page;
+	struct exofs_dir_entry *de;
+	ino_t ino;
+
+	de = exofs_dotdot(child->d_inode, &page);
+	if (!de)
+		return 0;
+
+	ino = le64_to_cpu(de->inode_no);
+	exofs_put_page(page);
+	return ino;
+}
+
+ino_t exofs_inode_by_name(struct inode *dir, struct dentry *dentry)
+{
+	ino_t res = 0;
+	struct exofs_dir_entry *de;
+	struct page *page;
+
+	de = exofs_find_entry(dir, dentry, &page);
+	if (de) {
+		res = le64_to_cpu(de->inode_no);
+		exofs_put_page(page);
+	}
+	return res;
+}
+
+int exofs_set_link(struct inode *dir, struct exofs_dir_entry *de,
+			struct page *page, struct inode *inode)
+{
+	loff_t pos = page_offset(page) +
+			(char *) de - (char *) page_address(page);
+	unsigned len = le16_to_cpu(de->rec_len);
+	int err;
+
+	lock_page(page);
+	err = exofs_write_begin(NULL, page->mapping, pos, len,
+				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+	if (err)
+		EXOFS_ERR("exofs_set_link: exofs_write_begin FAILD => %d\n",
+			  err);
+
+	de->inode_no = cpu_to_le64(inode->i_ino);
+	exofs_set_de_type(de, inode);
+	if (likely(!err))
+		err = exofs_commit_chunk(page, pos, len);
+	exofs_put_page(page);
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(dir);
+	return err;
+}
+
+int exofs_add_link(struct dentry *dentry, struct inode *inode)
+{
+	struct inode *dir = dentry->d_parent->d_inode;
+	const unsigned char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	unsigned chunk_size = exofs_chunk_size(dir);
+	unsigned reclen = EXOFS_DIR_REC_LEN(namelen);
+	unsigned short rec_len, name_len;
+	struct page *page = NULL;
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+	struct exofs_dir_entry *de;
+	unsigned long npages = dir_pages(dir);
+	unsigned long n;
+	char *kaddr;
+	loff_t pos;
+	int err;
+
+	for (n = 0; n <= npages; n++) {
+		char *dir_end;
+
+		page = exofs_get_page(dir, n);
+		err = PTR_ERR(page);
+		if (IS_ERR(page))
+			goto out;
+		lock_page(page);
+		kaddr = page_address(page);
+		dir_end = kaddr + exofs_last_byte(dir, n);
+		de = (struct exofs_dir_entry *)kaddr;
+		kaddr += PAGE_CACHE_SIZE - reclen;
+		while ((char *)de <= kaddr) {
+			if ((char *)de == dir_end) {
+				name_len = 0;
+				rec_len = chunk_size;
+				de->rec_len = cpu_to_le16(chunk_size);
+				de->inode_no = 0;
+				goto got_it;
+			}
+			if (de->rec_len == 0) {
+				EXOFS_ERR("ERROR: exofs_add_link: "
+					"zero-length directory entry");
+				err = -EIO;
+				goto out_unlock;
+			}
+			err = -EEXIST;
+			if (exofs_match(namelen, name, de))
+				goto out_unlock;
+			name_len = EXOFS_DIR_REC_LEN(de->name_len);
+			rec_len = le16_to_cpu(de->rec_len);
+			if (!de->inode_no && rec_len >= reclen)
+				goto got_it;
+			if (rec_len >= name_len + reclen)
+				goto got_it;
+			de = (struct exofs_dir_entry *) ((char *) de + rec_len);
+		}
+		unlock_page(page);
+		exofs_put_page(page);
+	}
+
+	EXOFS_ERR("exofs_add_link: BAD dentry=%p or inode=%p", dentry, inode);
+	return -EINVAL;
+
+got_it:
+	pos = page_offset(page) +
+		(char *)de - (char *)page_address(page);
+	err = exofs_write_begin(NULL, page->mapping, pos, rec_len, 0,
+							&page, NULL);
+	if (err)
+		goto out_unlock;
+	if (de->inode_no) {
+		struct exofs_dir_entry *de1 =
+			(struct exofs_dir_entry *)((char *)de + name_len);
+		de1->rec_len = cpu_to_le16(rec_len - name_len);
+		de->rec_len = cpu_to_le16(name_len);
+		de = de1;
+	}
+	de->name_len = namelen;
+	memcpy(de->name, name, namelen);
+	de->inode_no = cpu_to_le64(inode->i_ino);
+	exofs_set_de_type(de, inode);
+	err = exofs_commit_chunk(page, pos, rec_len);
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+	mark_inode_dirty(dir);
+	sbi->s_numfiles++;
+
+out_put:
+	exofs_put_page(page);
+out:
+	return err;
+out_unlock:
+	unlock_page(page);
+	goto out_put;
+}
+
+int exofs_delete_entry(struct exofs_dir_entry *dir, struct page *page)
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
+	char *kaddr = page_address(page);
+	unsigned from = ((char *)dir - kaddr) & ~(exofs_chunk_size(inode)-1);
+	unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len);
+	loff_t pos;
+	struct exofs_dir_entry *pde = NULL;
+	struct exofs_dir_entry *de = (struct exofs_dir_entry *) (kaddr + from);
+	int err;
+
+	while (de < dir) {
+		if (de->rec_len == 0) {
+			EXOFS_ERR("ERROR: exofs_delete_entry:"
+				"zero-length directory entry");
+			err = -EIO;
+			goto out;
+		}
+		pde = de;
+		de = exofs_next_entry(de);
+	}
+	if (pde)
+		from = (char *)pde - (char *)page_address(page);
+	pos = page_offset(page) + from;
+	lock_page(page);
+	err = exofs_write_begin(NULL, page->mapping, pos, to - from, 0,
+							&page, NULL);
+	if (err)
+		EXOFS_ERR("exofs_delete_entry: exofs_write_begin FAILD => %d\n",
+			  err);
+	if (pde)
+		pde->rec_len = cpu_to_le16(to - from);
+	dir->inode_no = 0;
+	if (likely(!err))
+		err = exofs_commit_chunk(page, pos, to - from);
+	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+	mark_inode_dirty(inode);
+	sbi->s_numfiles--;
+out:
+	exofs_put_page(page);
+	return err;
+}
+
+/* kept aligned on 4 bytes */
+#define THIS_DIR ".\0\0"
+#define PARENT_DIR "..\0"
+
+int exofs_make_empty(struct inode *inode, struct inode *parent)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page = grab_cache_page(mapping, 0);
+	unsigned chunk_size = exofs_chunk_size(inode);
+	struct exofs_dir_entry *de;
+	int err;
+	void *kaddr;
+
+	if (!page)
+		return -ENOMEM;
+
+	err = exofs_write_begin(NULL, page->mapping, 0, chunk_size, 0,
+							&page, NULL);
+	if (err) {
+		unlock_page(page);
+		goto fail;
+	}
+
+	kaddr = kmap_atomic(page, KM_USER0);
+	de = (struct exofs_dir_entry *)kaddr;
+	de->name_len = 1;
+	de->rec_len = cpu_to_le16(EXOFS_DIR_REC_LEN(1));
+	memcpy(de->name, THIS_DIR, sizeof(THIS_DIR));
+	de->inode_no = cpu_to_le64(inode->i_ino);
+	exofs_set_de_type(de, inode);
+
+	de = (struct exofs_dir_entry *)(kaddr + EXOFS_DIR_REC_LEN(1));
+	de->name_len = 2;
+	de->rec_len = cpu_to_le16(chunk_size - EXOFS_DIR_REC_LEN(1));
+	de->inode_no = cpu_to_le64(parent->i_ino);
+	memcpy(de->name, PARENT_DIR, sizeof(PARENT_DIR));
+	exofs_set_de_type(de, inode);
+	kunmap_atomic(page, KM_USER0);
+	err = exofs_commit_chunk(page, 0, chunk_size);
+fail:
+	page_cache_release(page);
+	return err;
+}
+
+int exofs_empty_dir(struct inode *inode)
+{
+	struct page *page = NULL;
+	unsigned long i, npages = dir_pages(inode);
+
+	for (i = 0; i < npages; i++) {
+		char *kaddr;
+		struct exofs_dir_entry *de;
+		page = exofs_get_page(inode, i);
+
+		if (IS_ERR(page))
+			continue;
+
+		kaddr = page_address(page);
+		de = (struct exofs_dir_entry *)kaddr;
+		kaddr += exofs_last_byte(inode, i) - EXOFS_DIR_REC_LEN(1);
+
+		while ((char *)de <= kaddr) {
+			if (de->rec_len == 0) {
+				EXOFS_ERR("ERROR: exofs_empty_dir: "
+					  "zero-length directory entry"
+					  "kaddr=%p, de=%p\n", kaddr, de);
+				goto not_empty;
+			}
+			if (de->inode_no != 0) {
+				/* check for . and .. */
+				if (de->name[0] != '.')
+					goto not_empty;
+				if (de->name_len > 2)
+					goto not_empty;
+				if (de->name_len < 2) {
+					if (le64_to_cpu(de->inode_no) !=
+					    inode->i_ino)
+						goto not_empty;
+				} else if (de->name[1] != '.')
+					goto not_empty;
+			}
+			de = exofs_next_entry(de);
+		}
+		exofs_put_page(page);
+	}
+	return 1;
+
+not_empty:
+	exofs_put_page(page);
+	return 0;
+}
+
+const struct file_operations exofs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.readdir	= exofs_readdir,
+};
diff --git a/fs/exofs/exofs.h b/fs/exofs/exofs.h
new file mode 100644
index 00000000000..0fd4c785967
--- /dev/null
+++ b/fs/exofs/exofs.h
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2005, 2006
+ * Avishay Traeger (avishay@gmail.com) (avishay@il.ibm.com)
+ * Copyright (C) 2005, 2006
+ * International Business Machines
+ * Copyright (C) 2008, 2009
+ * Boaz Harrosh <bharrosh@panasas.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/fs.h>
+#include <linux/time.h>
+#include "common.h"
+
+#ifndef __EXOFS_H__
+#define __EXOFS_H__
+
+#define EXOFS_ERR(fmt, a...) printk(KERN_ERR "exofs: " fmt, ##a)
+
+#ifdef CONFIG_EXOFS_DEBUG
+#define EXOFS_DBGMSG(fmt, a...) \
+	printk(KERN_NOTICE "exofs @%s:%d: " fmt, __func__, __LINE__, ##a)
+#else
+#define EXOFS_DBGMSG(fmt, a...) \
+	do { if (0) printk(fmt, ##a); } while (0)
+#endif
+
+/* u64 has problems with printk this will cast it to unsigned long long */
+#define _LLU(x) (unsigned long long)(x)
+
+/*
+ * our extension to the in-memory superblock
+ */
+struct exofs_sb_info {
+	struct osd_dev	*s_dev;			/* returned by get_osd_dev    */
+	osd_id		s_pid;			/* partition ID of file system*/
+	int		s_timeout;		/* timeout for OSD operations */
+	uint64_t	s_nextid;		/* highest object ID used     */
+	uint32_t	s_numfiles;		/* number of files on fs      */
+	spinlock_t	s_next_gen_lock;	/* spinlock for gen # update  */
+	u32		s_next_generation;	/* next gen # to use          */
+	atomic_t	s_curr_pending;		/* number of pending commands */
+	uint8_t		s_cred[OSD_CAP_LEN];	/* all-powerful credential    */
+};
+
+/*
+ * our extension to the in-memory inode
+ */
+struct exofs_i_info {
+	unsigned long  i_flags;            /* various atomic flags            */
+	uint32_t       i_data[EXOFS_IDATA];/*short symlink names and device #s*/
+	uint32_t       i_dir_start_lookup; /