exofs: Move all operations to an io_engine

In anticipation for multi-device operations, we separate osd operations
into an abstract I/O API. Currently only one device is used but later
when adding more devices, we will drive all devices in parallel according
to a "data_map" that describes how data is arranged on multiple devices.
The file system level operates, like before, as if there is one object
(inode-number) and an i_size. The io engine will split this to the same
object-number but on multiple device.

At first we introduce Mirror (raid 1) layout. But at the final outcome
we intend to fully implement the pNFS-Objects data-map, including
raid 0,4,5,6 over mirrored devices, over multiple device-groups. And
more. See: http://tools.ietf.org/html/draft-ietf-nfsv4-pnfs-obj-12

* Define an io_state based API for accessing osd storage devices
  in an abstract way.
  Usage:
	First a caller allocates an io state with:
		exofs_get_io_state(struct exofs_sb_info *sbi,
				   struct exofs_io_state** ios);

	Then calles one of:
		exofs_sbi_create(struct exofs_io_state *ios);
		exofs_sbi_remove(struct exofs_io_state *ios);
		exofs_sbi_write(struct exofs_io_state *ios);
		exofs_sbi_read(struct exofs_io_state *ios);
		exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len);

	And when done
		exofs_put_io_state(struct exofs_io_state *ios);

* Convert all source files to use this new API
* Convert from bio_alloc to bio_kmalloc
* In io engine we make use of the now fixed osd_req_decode_sense

There are no functional changes or on disk additions after this patch.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

1 files changed, 333 insertions, 53 deletions

diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
index 4372542df284..bb2f9d341fdf 100644
--- a/fs/exofs/ios.c
+++ b/fs/exofs/ios.c
@@ -23,88 +23,327 @@
  */
 
 #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)
+void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
 {
-	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;
+	osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
+}
+
+int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
+		    u64 offset, void *p, unsigned length)
+{
+	struct osd_request *or = osd_start_request(od, GFP_KERNEL);
+/*	struct osd_sense_info osi = {.key = 0};*/
+	int ret;
+
+	if (unlikely(!or)) {
+		EXOFS_DBGMSG("%s: osd_start_request failed.\n", __func__);
+		return -ENOMEM;
+	}
+	ret = osd_req_read_kern(or, obj, offset, p, length);
+	if (unlikely(ret)) {
+		EXOFS_DBGMSG("%s: osd_req_read_kern failed.\n", __func__);
+		goto out;
 	}
 
-	/* FIXME: should be include in osd_sense_info */
-	if (in_resid)
-		*in_resid = or->in.req ? or->in.req->resid_len : 0;
+	ret = osd_finalize_request(or, 0, cred, NULL);
+	if (unlikely(ret)) {
+		EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
+		goto out;
+	}
 
-	if (out_resid)
-		*out_resid = or->out.req ? or->out.req->resid_len : 0;
+	ret = osd_execute_request(or);
+	if (unlikely(ret))
+		EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
+	/* osd_req_decode_sense(or, ret); */
 
+out:
+	osd_end_request(or);
 	return ret;
 }
 
-void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
+int exofs_get_io_state(struct exofs_sb_info *sbi, struct exofs_io_state** pios)
 {
-	osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
+	struct exofs_io_state *ios;
+
+	/*TODO: Maybe use kmem_cach per sbi of size
+	 * exofs_io_state_size(sbi->s_numdevs)
+	 */
+	ios = kzalloc(exofs_io_state_size(1), GFP_KERNEL);
+	if (unlikely(!ios)) {
+		*pios = NULL;
+		return -ENOMEM;
+	}
+
+	ios->sbi = sbi;
+	ios->obj.partition = sbi->s_pid;
+	*pios = ios;
+	return 0;
 }
 
-/*
- * Perform a synchronous OSD operation.
- */
-int exofs_sync_op(struct osd_request *or, int timeout, uint8_t *credential)
+void exofs_put_io_state(struct exofs_io_state *ios)
 {
-	int ret;
+	if (ios) {
+		unsigned i;
 
-	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;
+		for (i = 0; i < ios->numdevs; i++) {
+			struct exofs_per_dev_state *per_dev = &ios->per_dev[i];
+
+			if (per_dev->or)
+				osd_end_request(per_dev->or);
+			if (per_dev->bio)
+				bio_put(per_dev->bio);
+		}
+
+		kfree(ios);
 	}
+}
 
-	ret = osd_execute_request(or);
+static void _sync_done(struct exofs_io_state *ios, void *p)
+{
+	struct completion *waiting = p;
 
-	if (ret)
-		EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
-	/* osd_req_decode_sense(or, ret); */
+	complete(waiting);
+}
+
+static void _last_io(struct kref *kref)
+{
+	struct exofs_io_state *ios = container_of(
+					kref, struct exofs_io_state, kref);
+
+	ios->done(ios, ios->private);
+}
+
+static void _done_io(struct osd_request *or, void *p)
+{
+	struct exofs_io_state *ios = p;
+
+	kref_put(&ios->kref, _last_io);
+}
+
+static int exofs_io_execute(struct exofs_io_state *ios)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	bool sync = (ios->done == NULL);
+	int i, ret;
+
+	if (sync) {
+		ios->done = _sync_done;
+		ios->private = &wait;
+	}
+
+	for (i = 0; i < ios->numdevs; i++) {
+		struct osd_request *or = ios->per_dev[i].or;
+		if (unlikely(!or))
+			continue;
+
+		ret = osd_finalize_request(or, 0, ios->cred, NULL);
+		if (unlikely(ret)) {
+			EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n",
+				     ret);
+			return ret;
+		}
+	}
+
+	kref_init(&ios->kref);
+
+	for (i = 0; i < ios->numdevs; i++) {
+		struct osd_request *or = ios->per_dev[i].or;
+		if (unlikely(!or))
+			continue;
+
+		kref_get(&ios->kref);
+		osd_execute_request_async(or, _done_io, ios);
+	}
+
+	kref_put(&ios->kref, _last_io);
+	ret = 0;
+
+	if (sync) {
+		wait_for_completion(&wait);
+		ret = exofs_check_io(ios, NULL);
+	}
 	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 exofs_check_io(struct exofs_io_state *ios, u64 *resid)
 {
-	int ret;
+	enum osd_err_priority acumulated_osd_err = 0;
+	int acumulated_lin_err = 0;
+	int i;
 
-	ret = osd_finalize_request(or, 0, cred, NULL);
-	if (ret) {
-		EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
-		return ret;
+	for (i = 0; i < ios->numdevs; i++) {
+		struct osd_sense_info osi;
+		int ret = osd_req_decode_sense(ios->per_dev[i].or, &osi);
+
+		if (likely(!ret))
+			continue;
+
+		if (unlikely(ret == -EFAULT)) {
+			EXOFS_DBGMSG("%s: EFAULT Need page clear\n", __func__);
+			/*FIXME: All the pages in this device range should:
+			 *	clear_highpage(page);
+			 */
+		}
+
+		if (osi.osd_err_pri >= acumulated_osd_err) {
+			acumulated_osd_err = osi.osd_err_pri;
+			acumulated_lin_err = ret;
+		}
+	}
+
+	/* TODO: raid specific residual calculations */
+	if (resid) {
+		if (likely(!acumulated_lin_err))
+			*resid = 0;
+		else
+			*resid = ios->length;
+	}
+
+	return acumulated_lin_err;
+}
+
+int exofs_sbi_create(struct exofs_io_state *ios)
+{
+	int i, ret;
+
+	for (i = 0; i < 1; i++) {
+		struct osd_request *or;
+
+		or = osd_start_request(ios->sbi->s_dev, GFP_KERNEL);
+		if (unlikely(!or)) {
+			EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+			ret = -ENOMEM;
+			goto out;
+		}
+		ios->per_dev[i].or = or;
+		ios->numdevs++;
+
+		osd_req_create_object(or, &ios->obj);
+	}
+	ret = exofs_io_execute(ios);
+
+out:
+	return ret;
+}
+
+int exofs_sbi_remove(struct exofs_io_state *ios)
+{
+	int i, ret;
+
+	for (i = 0; i < 1; i++) {
+		struct osd_request *or;
+
+		or = osd_start_request(ios->sbi->s_dev, GFP_KERNEL);
+		if (unlikely(!or)) {
+			EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+			ret = -ENOMEM;
+			goto out;
+		}
+		ios->per_dev[i].or = or;
+		ios->numdevs++;
+
+		osd_req_remove_object(or, &ios->obj);
+	}
+	ret = exofs_io_execute(ios);
+
+out:
+	return ret;
+}
+
+int exofs_sbi_write(struct exofs_io_state *ios)
+{
+	int i, ret;
+
+	for (i = 0; i < 1; i++) {
+		struct osd_request *or;
+
+		or = osd_start_request(ios->sbi->s_dev, GFP_KERNEL);
+		if (unlikely(!or)) {
+			EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+			ret = -ENOMEM;
+			goto out;
+		}
+		ios->per_dev[i].or = or;
+		ios->numdevs++;
+
+		if (ios->bio) {
+			struct bio *bio;
+
+			bio = ios->bio;
+
+			osd_req_write(or, &ios->obj, ios->offset, bio,
+				      ios->length);
+/*			EXOFS_DBGMSG("write sync=%d\n", sync);*/
+		} else if (ios->kern_buff) {
+			osd_req_write_kern(or, &ios->obj, ios->offset,
+					   ios->kern_buff, ios->length);
+/*			EXOFS_DBGMSG("write_kern sync=%d\n", sync);*/
+		} else {
+			osd_req_set_attributes(or, &ios->obj);
+/*			EXOFS_DBGMSG("set_attributes sync=%d\n", sync);*/
+		}
+
+		if (ios->out_attr)
+			osd_req_add_set_attr_list(or, ios->out_attr,
+						  ios->out_attr_len);
+
+		if (ios->in_attr)
+			osd_req_add_get_attr_list(or, ios->in_attr,
+						  ios->in_attr_len);
 	}
+	ret = exofs_io_execute(ios);
+
+out:
+	return ret;
+}
+
+int exofs_sbi_read(struct exofs_io_state *ios)
+{
+	int i, ret;
+
+	for (i = 0; i < 1; i++) {
+		struct osd_request *or;
+
+		or = osd_start_request(ios->sbi->s_dev, GFP_KERNEL);
+		if (unlikely(!or)) {
+			EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+			ret = -ENOMEM;
+			goto out;
+		}
+		ios->per_dev[i].or = or;
+		ios->numdevs++;
+
+		if (ios->bio) {
+			osd_req_read(or, &ios->obj, ios->offset, ios->bio,
+				     ios->length);
+/*			EXOFS_DBGMSG("read sync=%d\n", sync);*/
+		} else if (ios->kern_buff) {
+			osd_req_read_kern(or, &ios->obj, ios->offset,
+					   ios->kern_buff, ios->length);
+/*			EXOFS_DBGMSG("read_kern sync=%d\n", sync);*/
+		} else {
+			osd_req_get_attributes(or, &ios->obj);
+/*			EXOFS_DBGMSG("get_attributes sync=%d\n", sync);*/
+		}
+
+		if (ios->out_attr)
+			osd_req_add_set_attr_list(or, ios->out_attr,
+						  ios->out_attr_len);
 
-	ret = osd_execute_request_async(or, async_done, caller_context);
+		if (ios->in_attr)
+			osd_req_add_get_attr_list(or, ios->in_attr,
+						  ios->in_attr_len);
+	}
+	ret = exofs_io_execute(ios);
 
-	if (ret)
-		EXOFS_DBGMSG("osd_execute_request_async() => %d\n", ret);
+out:
 	return ret;
 }
 
-int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr)
+int extract_attr_from_ios(struct exofs_io_state *ios, struct osd_attr *attr)
 {
 	struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
 	void *iter = NULL;
@@ -112,7 +351,8 @@ int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr)
 
 	do {
 		nelem = 1;
-		osd_req_decode_get_attr_list(or, &cur_attr, &nelem, &iter);
+		osd_req_decode_get_attr_list(ios->per_dev[0].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;
@@ -123,3 +363,43 @@ int extract_attr_from_req(struct osd_request *or, struct osd_attr *attr)
 
 	return -EIO;
 }
+
+int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
+{
+	struct exofs_sb_info *sbi = oi->vfs_inode.i_sb->s_fs_info;
+	struct exofs_io_state *ios;
+	struct osd_attr attr;
+	__be64 newsize;
+	int i, ret;
+
+	if (exofs_get_io_state(sbi, &ios))
+		return -ENOMEM;
+
+	ios->obj.id = exofs_oi_objno(oi);
+	ios->cred = oi->i_cred;
+
+	newsize = cpu_to_be64(size);
+	attr = g_attr_logical_length;
+	attr.val_ptr = &newsize;
+
+	for (i = 0; i < 1; i++) {
+		struct osd_request *or;
+
+		or = osd_start_request(sbi->s_dev, GFP_KERNEL);
+		if (unlikely(!or)) {
+			EXOFS_ERR("%s: osd_start_request failed\n", __func__);
+			ret = -ENOMEM;
+			goto out;
+		}
+		ios->per_dev[i].or = or;
+		ios->numdevs++;
+
+		osd_req_set_attributes(or, &ios->obj);
+		osd_req_add_set_attr_list(or, &attr, 1);
+	}
+	ret = exofs_io_execute(ios);
+
+out:
+	exofs_put_io_state(ios);
+	return ret;
+}