osd_ore.h

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/*
 * 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;
};

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