diff options
Diffstat (limited to 'fs/qnx6/super_mmi.c')
| -rw-r--r-- | fs/qnx6/super_mmi.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/fs/qnx6/super_mmi.c b/fs/qnx6/super_mmi.c new file mode 100644 index 000000000000..29c32cba62d6 --- /dev/null +++ b/fs/qnx6/super_mmi.c @@ -0,0 +1,150 @@ +/* + * 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) { + printk(KERN_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) { + printk(KERN_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)) { + printk(KERN_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))) { + printk(KERN_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) { + printk(KERN_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) + printk(KERN_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)) { + printk(KERN_ERR "qnx6: superblock #1 checksum error\n"); + goto out; + } + + qsb = kmalloc(sizeof(*qsb), GFP_KERNEL); + if (!qsb) { + printk(KERN_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); + printk(KERN_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); + printk(KERN_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; +} |