util.c

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/*
 *  linux/fs/ufs/util.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <[email protected]>
 * Charles University, Faculty of Mathematics and Physics
 */
 
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>

#include "ufs_fs.h"
#include "ufs.h"
#include "swab.h"
#include "util.h"

struct ufs_buffer_head * _ubh_bread_ (struct ufs_sb_private_info * uspi,
    struct super_block *sb, u64 fragment, u64 size)
{
    struct ufs_buffer_head * ubh;
    unsigned i, j ;
    u64  count = 0;
    if (size & ~uspi->s_fmask)
        return NULL;
    count = size >> uspi->s_fshift;
    if (count > UFS_MAXFRAG)
        return NULL;
    ubh = (struct ufs_buffer_head *)
        kmalloc (sizeof (struct ufs_buffer_head), GFP_NOFS);
    if (!ubh)
        return NULL;
    ubh->fragment = fragment;
    ubh->count = count;
    for (i = 0; i < count; i++)
        if (!(ubh->bh[i] = sb_bread(sb, fragment + i)))
            goto failed;
    for (; i < UFS_MAXFRAG; i++)
        ubh->bh[i] = NULL;
    return ubh;
failed:
    for (j = 0; j < i; j++)
        brelse (ubh->bh[j]);
    kfree(ubh);
    return NULL;
}

struct ufs_buffer_head * ubh_bread_uspi (struct ufs_sb_private_info * uspi,
    struct super_block *sb, u64 fragment, u64 size)
{
    unsigned i, j;
    u64 count = 0;
    if (size & ~uspi->s_fmask)
        return NULL;
    count = size >> uspi->s_fshift;
    if (count <= 0 || count > UFS_MAXFRAG)
        return NULL;
    USPI_UBH(uspi)->fragment = fragment;
    USPI_UBH(uspi)->count = count;
    for (i = 0; i < count; i++)
        if (!(USPI_UBH(uspi)->bh[i] = sb_bread(sb, fragment + i)))
            goto failed;
    for (; i < UFS_MAXFRAG; i++)
        USPI_UBH(uspi)->bh[i] = NULL;
    return USPI_UBH(uspi);
failed:
    for (j = 0; j < i; j++)
        brelse (USPI_UBH(uspi)->bh[j]);
    return NULL;
}

void ubh_brelse (struct ufs_buffer_head * ubh)
{
    unsigned i;
    if (!ubh)
        return;
    for (i = 0; i < ubh->count; i++)
        brelse (ubh->bh[i]);
    kfree (ubh);
}

void ubh_brelse_uspi (struct ufs_sb_private_info * uspi)
{
    unsigned i;
    if (!USPI_UBH(uspi))
        return;
    for ( i = 0; i < USPI_UBH(uspi)->count; i++ ) {
        brelse (USPI_UBH(uspi)->bh[i]);
        USPI_UBH(uspi)->bh[i] = NULL;
    }
}

void ubh_mark_buffer_dirty (struct ufs_buffer_head * ubh)
{
    unsigned i;
    if (!ubh)
        return;
    for ( i = 0; i < ubh->count; i++ )
        mark_buffer_dirty (ubh->bh[i]);
}

void ubh_mark_buffer_uptodate (struct ufs_buffer_head * ubh, int flag)
{
    unsigned i;
    if (!ubh)
        return;
    if (flag) {
        for ( i = 0; i < ubh->count; i++ )
            set_buffer_uptodate (ubh->bh[i]);
    } else {
        for ( i = 0; i < ubh->count; i++ )
            clear_buffer_uptodate (ubh->bh[i]);
    }
}

void ubh_sync_block(struct ufs_buffer_head *ubh)
{
    if (ubh) {
        unsigned i;

        for (i = 0; i < ubh->count; i++)
            write_dirty_buffer(ubh->bh[i], WRITE);

        for (i = 0; i < ubh->count; i++)
            wait_on_buffer(ubh->bh[i]);
    }
}

void ubh_bforget (struct ufs_buffer_head * ubh)
{
    unsigned i;
    if (!ubh) 
        return;
    for ( i = 0; i < ubh->count; i++ ) if ( ubh->bh[i] ) 
        bforget (ubh->bh[i]);
}
 
int ubh_buffer_dirty (struct ufs_buffer_head * ubh)
{
    unsigned i;
    unsigned result = 0;
    if (!ubh)
        return 0;
    for ( i = 0; i < ubh->count; i++ )
        result |= buffer_dirty(ubh->bh[i]);
    return result;
}

void _ubh_ubhcpymem_(struct ufs_sb_private_info * uspi, 
    unsigned char * mem, struct ufs_buffer_head * ubh, unsigned size)
{
    unsigned len, bhno;
    if (size > (ubh->count << uspi->s_fshift))
        size = ubh->count << uspi->s_fshift;
    bhno = 0;
    while (size) {
        len = min_t(unsigned int, size, uspi->s_fsize);
        memcpy (mem, ubh->bh[bhno]->b_data, len);
        mem += uspi->s_fsize;
        size -= len;
        bhno++;
    }
}

void _ubh_memcpyubh_(struct ufs_sb_private_info * uspi, 
    struct ufs_buffer_head * ubh, unsigned char * mem, unsigned size)
{
    unsigned len, bhno;
    if (size > (ubh->count << uspi->s_fshift))
        size = ubh->count << uspi->s_fshift;
    bhno = 0;
    while (size) {
        len = min_t(unsigned int, size, uspi->s_fsize);
        memcpy (ubh->bh[bhno]->b_data, mem, len);
        mem += uspi->s_fsize;
        size -= len;
        bhno++;
    }
}

dev_t
ufs_get_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi)
{
    __u32 fs32;
    dev_t dev;

    if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
        fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[1]);
    else
        fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[0]);
    switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
    case UFS_ST_SUNx86:
    case UFS_ST_SUN:
        if ((fs32 & 0xffff0000) == 0 ||
            (fs32 & 0xffff0000) == 0xffff0000)
            dev = old_decode_dev(fs32 & 0x7fff);
        else
            dev = MKDEV(sysv_major(fs32), sysv_minor(fs32));
        break;

    default:
        dev = old_decode_dev(fs32);
        break;
    }
    return dev;
}

void
ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev)
{
    __u32 fs32;

    switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
    case UFS_ST_SUNx86:
    case UFS_ST_SUN:
        fs32 = sysv_encode_dev(dev);
        if ((fs32 & 0xffff8000) == 0) {
            fs32 = old_encode_dev(dev);
        }
        break;

    default:
        fs32 = old_encode_dev(dev);
        break;
    }
    if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
        ufsi->i_u1.i_data[1] = cpu_to_fs32(sb, fs32);
    else
        ufsi->i_u1.i_data[0] = cpu_to_fs32(sb, fs32);
}

struct page *ufs_get_locked_page(struct address_space *mapping,
                 pgoff_t index)
{
    struct page *page;

    page = find_lock_page(mapping, index);
    if (!page) {
        page = read_mapping_page(mapping, index, NULL);

        if (IS_ERR(page)) {
            printk(KERN_ERR "ufs_change_blocknr: "
                   "read_mapping_page error: ino %lu, index: %lu\n",
                   mapping->host->i_ino, index);
            goto out;
        }

        lock_page(page);

        if (unlikely(page->mapping == NULL)) {
            /* Truncate got there first */
            unlock_page(page);
            page_cache_release(page);
            page = NULL;
            goto out;
        }

        if (!PageUptodate(page) || PageError(page)) {
            unlock_page(page);
            page_cache_release(page);

            printk(KERN_ERR "ufs_change_blocknr: "
                   "can not read page: ino %lu, index: %lu\n",
                   mapping->host->i_ino, index);

            page = ERR_PTR(-EIO);
        }
    }
out:
    return page;
}