Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / qnx6 / super_mmi.c

diff --git a/kernel/fs/qnx6/super_mmi.c b/kernel/fs/qnx6/super_mmi.c
new file mode 100644 (file)
index 0000000..62aaf3e
--- /dev/null
+++ b/kernel/fs/qnx6/super_mmi.c
@@ -0,0 +1,148 @@
+/*
+ * 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("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("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("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("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("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("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("superblock #1 checksum error\n");
+               goto out;
+       }
+
+       qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
+       if (!qsb) {
+               pr_err("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("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("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;
+}