5d026c7242
Adds support for qnx6fs readonly support to the linux kernel. * Mount option The option mmi_fs can be used to mount Harman Becker/Audi MMI 3G HDD qnx6fs filesystems. * Documentation A high level filesystem stucture description can be found in the Documentation/filesystems directory. (qnx6.txt) * Additional features - Active (stable) superblock selection - Superblock checksum check (enforced) - Supports mount of qnx6 filesystems with to host different endianess - Automatic endianess detection - Longfilename support (with non-enfocing crc check) - All blocksizes (512, 1024, 2048 and 4096 supported) Signed-off-by: Kai Bankett <chaosman@ontika.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
151 lines
3.9 KiB
C
151 lines
3.9 KiB
C
/*
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* QNX6 file system, Linux implementation.
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*
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* Version : 1.0.0
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*
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* History :
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*
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* 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
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*
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*/
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#include <linux/buffer_head.h>
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#include <linux/slab.h>
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#include <linux/crc32.h>
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#include "qnx6.h"
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static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,
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struct qnx6_mmi_super_block *sb)
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{
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qsb->sb_magic = sb->sb_magic;
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qsb->sb_checksum = sb->sb_checksum;
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qsb->sb_serial = sb->sb_serial;
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qsb->sb_blocksize = sb->sb_blocksize;
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qsb->sb_num_inodes = sb->sb_num_inodes;
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qsb->sb_free_inodes = sb->sb_free_inodes;
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qsb->sb_num_blocks = sb->sb_num_blocks;
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qsb->sb_free_blocks = sb->sb_free_blocks;
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/* the rest of the superblock is the same */
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memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));
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memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));
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memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));
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}
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struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent)
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{
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struct buffer_head *bh1, *bh2 = NULL;
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struct qnx6_mmi_super_block *sb1, *sb2;
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struct qnx6_super_block *qsb = NULL;
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struct qnx6_sb_info *sbi;
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__u64 offset;
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/* Check the superblock signatures
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start with the first superblock */
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bh1 = sb_bread(s, 0);
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if (!bh1) {
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printk(KERN_ERR "qnx6: Unable to read first mmi superblock\n");
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return NULL;
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}
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sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
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sbi = QNX6_SB(s);
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if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {
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if (!silent) {
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printk(KERN_ERR "qnx6: wrong signature (magic) in"
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" superblock #1.\n");
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goto out;
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}
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}
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/* checksum check - start at byte 8 and end at byte 512 */
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if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
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crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
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printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
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goto out;
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}
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/* calculate second superblock blocknumber */
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offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA /
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fs32_to_cpu(sbi, sb1->sb_blocksize);
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/* set new blocksize */
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if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
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printk(KERN_ERR "qnx6: unable to set blocksize\n");
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goto out;
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}
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/* blocksize invalidates bh - pull it back in */
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brelse(bh1);
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bh1 = sb_bread(s, 0);
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if (!bh1)
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goto out;
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sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
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/* read second superblock */
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bh2 = sb_bread(s, offset);
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if (!bh2) {
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printk(KERN_ERR "qnx6: unable to read the second superblock\n");
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goto out;
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}
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sb2 = (struct qnx6_mmi_super_block *)bh2->b_data;
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if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
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if (!silent)
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printk(KERN_ERR "qnx6: wrong signature (magic) in"
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" superblock #2.\n");
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goto out;
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}
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/* checksum check - start at byte 8 and end at byte 512 */
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if (fs32_to_cpu(sbi, sb2->sb_checksum)
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!= crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
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printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
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goto out;
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}
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qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
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if (!qsb) {
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printk(KERN_ERR "qnx6: unable to allocate memory.\n");
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goto out;
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}
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if (fs64_to_cpu(sbi, sb1->sb_serial) >
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fs64_to_cpu(sbi, sb2->sb_serial)) {
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/* superblock #1 active */
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qnx6_mmi_copy_sb(qsb, sb1);
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#ifdef CONFIG_QNX6FS_DEBUG
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qnx6_superblock_debug(qsb, s);
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#endif
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memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));
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sbi->sb_buf = bh1;
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sbi->sb = (struct qnx6_super_block *)bh1->b_data;
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brelse(bh2);
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printk(KERN_INFO "qnx6: superblock #1 active\n");
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} else {
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/* superblock #2 active */
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qnx6_mmi_copy_sb(qsb, sb2);
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#ifdef CONFIG_QNX6FS_DEBUG
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qnx6_superblock_debug(qsb, s);
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#endif
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memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));
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sbi->sb_buf = bh2;
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sbi->sb = (struct qnx6_super_block *)bh2->b_data;
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brelse(bh1);
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printk(KERN_INFO "qnx6: superblock #2 active\n");
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}
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kfree(qsb);
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/* offset for mmi_fs is just SUPERBLOCK_AREA bytes */
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sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;
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/* success */
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return sbi->sb;
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out:
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if (bh1 != NULL)
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brelse(bh1);
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if (bh2 != NULL)
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brelse(bh2);
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return NULL;
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}
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