/*
* Copyright (C) 2011
* Boaz Harrosh <[email protected]>
*
* Public Declarations of the ORE API
*
* This file is part of the ORE (Object Raid Engine) library.
*
* ORE is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation. (GPL v2)
*
* ORE 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 the ORE; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __ORE_H__
#define __ORE_H__

#include <scsi/osd_initiator.h>
#include <scsi/osd_attributes.h>
#include <scsi/osd_sec.h>
#include <linux/pnfs_osd_xdr.h>
#include <linux/bug.h>

struct ore_comp {
struct osd_obj_id obj;
u8 cred[OSD_CAP_LEN];
};

struct ore_layout {
/* Our way of looking at the data_map */
enum pnfs_osd_raid_algorithm4
raid_algorithm;
unsigned stripe_unit;
unsigned mirrors_p1;

unsigned group_width;
unsigned parity;
u64 group_depth;
unsigned group_count;

/* Cached often needed calculations filled in by
* ore_verify_layout
*/
unsigned long max_io_length; /* Max length that should be passed to
* ore_get_rw_state
*/
};

struct ore_dev {
struct osd_dev *od;
};

struct ore_components {
unsigned first_dev; /* First logical device no */
unsigned numdevs; /* Num of devices in array */
/* If @single_comp == EC_SINGLE_COMP, @comps points to a single
* component. else there are @numdevs components
*/
enum EC_COMP_USAGE {
EC_SINGLE_COMP = 0, EC_MULTPLE_COMPS = 0xffffffff
} single_comp;
struct ore_comp *comps;

/* Array of pointers to ore_dev-* . User will usually have these pointed
* too a bigger struct which contain an "ore_dev ored" member and use
* container_of(oc->ods[i], struct foo_dev, ored) to access the bigger
* structure.
*/
struct ore_dev **ods;
};

/* ore_comp_dev Recievies a logical device index */
static inline struct osd_dev *ore_comp_dev(
const struct ore_components *oc, unsigned i)
{
BUG_ON((i < oc->first_dev) || (oc->first_dev + oc->numdevs <= i));
return oc->ods[i - oc->first_dev]->od;
}

static inline void ore_comp_set_dev(
struct ore_components *oc, unsigned i, struct osd_dev *od)
{
oc->ods[i - oc->first_dev]->od = od;
}

struct ore_striping_info {
u64 offset;
u64 obj_offset;
u64 length;
u64 first_stripe_start; /* only used in raid writes */
u64 M; /* for truncate */
unsigned bytes_in_stripe;
unsigned dev;
unsigned par_dev;
unsigned unit_off;
unsigned cur_pg;
unsigned cur_comp;
unsigned maxdevUnits;
};

struct ore_io_state;
typedef void (*ore_io_done_fn)(struct ore_io_state *ios, void *private);
struct _ore_r4w_op {
/* @Priv given here is passed ios->private */
struct page * (*get_page)(void *priv, u64 page_index, bool *uptodate);
void (*put_page)(void *priv, struct page *page);
};

struct ore_io_state {
struct kref kref;
struct ore_striping_info si;

void *private;
ore_io_done_fn done;

struct ore_layout *layout;
struct ore_components *oc;

/* Global read/write IO*/
loff_t offset;
unsigned long length;
void *kern_buff;

struct page **pages;
unsigned nr_pages;
unsigned pgbase;
unsigned pages_consumed;

/* Attributes */
unsigned in_attr_len;
struct osd_attr *in_attr;
unsigned out_attr_len;
struct osd_attr *out_attr;

bool reading;

/* House keeping of Parity pages */
bool extra_part_alloc;
struct page **parity_pages;
unsigned max_par_pages;
unsigned cur_par_page;
unsigned sgs_per_dev;
struct __stripe_pages_2d *sp2d;
struct ore_io_state *ios_read_4_write;
const struct _ore_r4w_op *r4w;

/* Variable array of size numdevs */
unsigned numdevs;
struct ore_per_dev_state {
struct osd_request *or;
struct bio *bio;
loff_t offset;
unsigned length;
unsigned last_sgs_total;
unsigned dev;
struct osd_sg_entry *sglist;
unsigned cur_sg;
} per_dev[];
};

static inline unsigned ore_io_state_size(unsigned numdevs)
{
return sizeof(struct ore_io_state) +
sizeof(struct ore_per_dev_state) * numdevs;
}

/* ore.c */
int ore_verify_layout(unsigned total_comps, struct ore_layout *layout);
void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
u64 length, struct ore_striping_info *si);
int ore_get_rw_state(struct ore_layout *layout, struct ore_components *comps,
bool is_reading, u64 offset, u64 length,
struct ore_io_state **ios);
int ore_get_io_state(struct ore_layout *layout, struct ore_components *comps,
struct ore_io_state **ios);
void ore_put_io_state(struct ore_io_state *ios);

typedef void (*ore_on_dev_error)(struct ore_io_state *ios, struct ore_dev *od,
unsigned dev_index, enum osd_err_priority oep,
u64 dev_offset, u64 dev_len);
int ore_check_io(struct ore_io_state *ios, ore_on_dev_error rep);

int ore_create(struct ore_io_state *ios);
int ore_remove(struct ore_io_state *ios);
int ore_write(struct ore_io_state *ios);
int ore_read(struct ore_io_state *ios);
int ore_truncate(struct ore_layout *layout, struct ore_components *comps,
u64 size);

int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr);

extern const struct osd_attr g_attr_logical_length;

#endif