exofs: Kbuild, Headers and osd utils

This patch includes osd infrastructure that will be used later by
the file system.

Also the declarations of constants, on disk structures,
and prototypes.

And the Kbuild+Kconfig files needed to build the exofs module.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/osd.c b/fs/exofs/osd.c
new file mode 100644
index 0000000..b249ae9
--- /dev/null
+++ b/fs/exofs/osd.c
@@ -0,0 +1,153 @@
+/*
+ * 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>
+ *
+ * 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 <scsi/scsi_device.h>
+#include <scsi/osd_sense.h>
+
+#include "exofs.h"
+
+int exofs_check_ok_resid(struct osd_request *or, u64 *in_resid, u64 *out_resid)
+{
+	struct osd_sense_info osi;
+	int ret = osd_req_decode_sense(or, &osi);
+
+	if (ret) { /* translate to Linux codes */
+		if (osi.additional_code == scsi_invalid_field_in_cdb) {
+			if (osi.cdb_field_offset == OSD_CFO_STARTING_BYTE)
+				ret = -EFAULT;
+			if (osi.cdb_field_offset == OSD_CFO_OBJECT_ID)
+				ret = -ENOENT;
+			else
+				ret = -EINVAL;
+		} else if (osi.additional_code == osd_quota_error)
+			ret = -ENOSPC;
+		else
+			ret = -EIO;
+	}
+
+	/* FIXME: should be include in osd_sense_info */
+	if (in_resid)
+		*in_resid = or->in.req ? or->in.req->data_len : 0;
+
+	if (out_resid)
+		*out_resid = or->out.req ? or->out.req->data_len : 0;
+
+	return ret;
+}
+
+void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
+{
+	osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
+}
+
+/*
+ * Perform a synchronous OSD operation.
+ */
+int exofs_sync_op(struct osd_request *or, int timeout, uint8_t *credential)
+{
+	int ret;
+
+	or->timeout = timeout;
+	ret = osd_finalize_request(or, 0, credential, NULL);
+	if (ret) {
+		EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
+		return ret;
+	}
+
+	ret = osd_execute_request(or);
+
+	if (ret)
+		EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
+	/* osd_req_decode_sense(or, ret); */
+	return ret;
+}
+
+/*
+ * Perform an asynchronous OSD operation.
+ */
+int exofs_async_op(struct osd_request *or, osd_req_done_fn *async_done,
+		   void *caller_context, u8 *cred)
+{
+	int ret;
+
+	ret = osd_finalize_request(or, 0, cred, NULL);
+	if (ret) {
+		EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
+		return ret;
+	}
+
+	ret = osd_execute_request_async(or, async_done, caller_context);
+
+	if (ret)
+		EXOFS_DBGMSG("osd_execute_request_async() => %d\n", ret);
+	return ret;
+}
+
+int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr)
+{
+	struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
+	void *iter = NULL;
+	int nelem;
+
+	do {
+		nelem = 1;
+		osd_req_decode_get_attr_list(or, &cur_attr, &nelem, &iter);
+		if ((cur_attr.attr_page == attr->attr_page) &&
+		    (cur_attr.attr_id == attr->attr_id)) {
+			attr->len = cur_attr.len;
+			attr->val_ptr = cur_attr.val_ptr;
+			return 0;
+		}
+	} while (iter);
+
+	return -EIO;
+}
+
+int osd_req_read_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void* buff, u64 len)
+{
+	struct request_queue *req_q = or->osd_dev->scsi_device->request_queue;
+	struct bio *bio = bio_map_kern(req_q, buff, len, GFP_KERNEL);
+
+	if (!bio)
+		return -ENOMEM;
+
+	osd_req_read(or, obj, bio, offset);
+	return 0;
+}
+
+int osd_req_write_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void* buff, u64 len)
+{
+	struct request_queue *req_q = or->osd_dev->scsi_device->request_queue;
+	struct bio *bio = bio_map_kern(req_q, buff, len, GFP_KERNEL);
+
+	if (!bio)
+		return -ENOMEM;
+
+	osd_req_write(or, obj, bio, offset);
+	return 0;
+}