linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * segbuf.c - NILFS segment buffer

 *

 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.

 *

 * Written by Ryusuke Konishi.

 *

 */

​

#include <linux/buffer_head.h>

#include <linux/writeback.h>

#include <linux/crc32.h>

#include <linux/backing-dev.h>

#include <linux/slab.h>

#include "page.h"

#include "segbuf.h"

​

​

struct nilfs_write_info {

    struct the_nilfs       *nilfs;

    struct bio         *bio;

    int         start, end; /* The region to be submitted */

    int         rest_blocks;

    int         max_pages;

    int         nr_vecs;

    sector_t        blocknr;

};

​

static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,

                  struct the_nilfs *nilfs);

static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);

​

struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)

{

    struct nilfs_segment_buffer *segbuf;

​

    segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);

    if (unlikely(!segbuf))

        return NULL;

​

    segbuf->sb_super = sb;

    INIT_LIST_HEAD(&segbuf->sb_list);

    INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);

    INIT_LIST_HEAD(&segbuf->sb_payload_buffers);

    segbuf->sb_super_root = NULL;

​

    init_completion(&segbuf->sb_bio_event);

    atomic_set(&segbuf->sb_err, 0);

    segbuf->sb_nbio = 0;

​

    return segbuf;

}

​

void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)

{

    kmem_cache_free(nilfs_segbuf_cachep, segbuf);

}

​

void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,

             unsigned long offset, struct the_nilfs *nilfs)

{

    segbuf->sb_segnum = segnum;

    nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,

                &segbuf->sb_fseg_end);

​

    segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;

    segbuf->sb_rest_blocks =

        segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;

}

​

/**

 * nilfs_segbuf_map_cont - map a new log behind a given log

 * @segbuf: new segment buffer

 * @prev: segment buffer containing a log to be continued

 */

void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,

               struct nilfs_segment_buffer *prev)

{

    segbuf->sb_segnum = prev->sb_segnum;

    segbuf->sb_fseg_start = prev->sb_fseg_start;

    segbuf->sb_fseg_end = prev->sb_fseg_end;

    segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;

    segbuf->sb_rest_blocks =

        segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;

}

​

void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,

                  __u64 nextnum, struct the_nilfs *nilfs)

{

    segbuf->sb_nextnum = nextnum;

    segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);