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/*
* QNX6 file system, Linux implementation.
*
* Version : 1.0.0
*
* History :
*
* 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
*
*/
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include "qnx6.h"
static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,
struct qnx6_mmi_super_block *sb)
{
qsb->sb_magic = sb->sb_magic;
qsb->sb_checksum = sb->sb_checksum;
qsb->sb_serial = sb->sb_serial;
qsb->sb_blocksize = sb->sb_blocksize;
qsb->sb_num_inodes = sb->sb_num_inodes;
qsb->sb_free_inodes = sb->sb_free_inodes;
qsb->sb_num_blocks = sb->sb_num_blocks;
qsb->sb_free_blocks = sb->sb_free_blocks;
/* the rest of the superblock is the same */
memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));
memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));
memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));
}
struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent)
{
struct buffer_head *bh1, *bh2 = NULL;
struct qnx6_mmi_super_block *sb1, *sb2;
struct qnx6_super_block *qsb = NULL;
struct qnx6_sb_info *sbi;
__u64 offset;
/* Check the superblock signatures
start with the first superblock */
bh1 = sb_bread(s, 0);
if (!bh1) {
pr_err("qnx6: Unable to read first mmi superblock\n");
return NULL;
}
sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
sbi = QNX6_SB(s);
if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {
if (!silent) {
pr_err("qnx6: wrong signature (magic) in superblock #1.\n");
goto out;
}
}
/* checksum check - start at byte 8 and end at byte 512 */
if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
pr_err("qnx6: superblock #1 checksum error\n");
goto out;
}
/* calculate second superblock blocknumber */
offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA /
fs32_to_cpu(sbi, sb1->sb_blocksize);
/* set new blocksize */
if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
pr_err("qnx6: unable to set blocksize\n");
goto out;
}
/* blocksize invalidates bh - pull it back in */
brelse(bh1);
bh1 = sb_bread(s, 0);
if (!bh1)
goto out;
sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
/* read second superblock */
bh2 = sb_bread(s, offset);
if (!bh2) {
pr_err("qnx6: unable to read the second superblock\n");
goto out;
}
sb2 = (struct qnx6_mmi_super_block *)bh2->b_data;
if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
if (!silent)
pr_err("qnx6: wrong signature (magic) in superblock #2.\n");
goto out;
}
/* checksum check - start at byte 8 and end at byte 512 */
if (fs32_to_cpu(sbi, sb2->sb_checksum)
!= crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
pr_err("qnx6: superblock #1 checksum error\n");
goto out;
}
qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
if (!qsb) {
pr_err("qnx6: unable to allocate memory.\n");
goto out;
}
if (fs64_to_cpu(sbi, sb1->sb_serial) >
fs64_to_cpu(sbi, sb2->sb_serial)) {
/* superblock #1 active */
qnx6_mmi_copy_sb(qsb, sb1);
#ifdef CONFIG_QNX6FS_DEBUG
qnx6_superblock_debug(qsb, s);
#endif
memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));
sbi->sb_buf = bh1;
sbi->sb = (struct qnx6_super_block *)bh1->b_data;
brelse(bh2);
pr_info("qnx6: superblock #1 active\n");
} else {
/* superblock #2 active */
qnx6_mmi_copy_sb(qsb, sb2);
#ifdef CONFIG_QNX6FS_DEBUG
qnx6_superblock_debug(qsb, s);
#endif
memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));
sbi->sb_buf = bh2;
sbi->sb = (struct qnx6_super_block *)bh2->b_data;
brelse(bh1);
pr_info("qnx6: superblock #2 active\n");
}
kfree(qsb);
/* offset for mmi_fs is just SUPERBLOCK_AREA bytes */
sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;
/* success */
return sbi->sb;
out:
if (bh1 != NULL)
brelse(bh1);
if (bh2 != NULL)
brelse(bh2);
return NULL;
}
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