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1// SPDX-License-Identifier: GPL-2.02/*3 * QNX6 file system, Linux implementation.4 *5 * Version : 1.0.06 *7 * History :8 *9 * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.10 *11 */12 13#include <linux/buffer_head.h>14#include <linux/slab.h>15#include <linux/crc32.h>16#include "qnx6.h"17 18static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,19 struct qnx6_mmi_super_block *sb)20{21 qsb->sb_magic = sb->sb_magic;22 qsb->sb_checksum = sb->sb_checksum;23 qsb->sb_serial = sb->sb_serial;24 qsb->sb_blocksize = sb->sb_blocksize;25 qsb->sb_num_inodes = sb->sb_num_inodes;26 qsb->sb_free_inodes = sb->sb_free_inodes;27 qsb->sb_num_blocks = sb->sb_num_blocks;28 qsb->sb_free_blocks = sb->sb_free_blocks;29 30 /* the rest of the superblock is the same */31 memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));32 memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));33 memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));34}35 36struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent)37{38 struct buffer_head *bh1, *bh2 = NULL;39 struct qnx6_mmi_super_block *sb1, *sb2;40 struct qnx6_super_block *qsb = NULL;41 struct qnx6_sb_info *sbi;42 __u64 offset;43 44 /* Check the superblock signatures45 start with the first superblock */46 bh1 = sb_bread(s, 0);47 if (!bh1) {48 pr_err("Unable to read first mmi superblock\n");49 return NULL;50 }51 sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;52 sbi = QNX6_SB(s);53 if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {54 if (!silent) {55 pr_err("wrong signature (magic) in superblock #1.\n");56 goto out;57 }58 }59 60 /* checksum check - start at byte 8 and end at byte 512 */61 if (fs32_to_cpu(sbi, sb1->sb_checksum) !=62 crc32_be(0, (char *)(bh1->b_data + 8), 504)) {63 pr_err("superblock #1 checksum error\n");64 goto out;65 }66 67 /* calculate second superblock blocknumber */68 offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA /69 fs32_to_cpu(sbi, sb1->sb_blocksize);70 71 /* set new blocksize */72 if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {73 pr_err("unable to set blocksize\n");74 goto out;75 }76 /* blocksize invalidates bh - pull it back in */77 brelse(bh1);78 bh1 = sb_bread(s, 0);79 if (!bh1)80 goto out;81 sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;82 83 /* read second superblock */84 bh2 = sb_bread(s, offset);85 if (!bh2) {86 pr_err("unable to read the second superblock\n");87 goto out;88 }89 sb2 = (struct qnx6_mmi_super_block *)bh2->b_data;90 if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {91 if (!silent)92 pr_err("wrong signature (magic) in superblock #2.\n");93 goto out;94 }95 96 /* checksum check - start at byte 8 and end at byte 512 */97 if (fs32_to_cpu(sbi, sb2->sb_checksum)98 != crc32_be(0, (char *)(bh2->b_data + 8), 504)) {99 pr_err("superblock #1 checksum error\n");100 goto out;101 }102 103 qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);104 if (!qsb) {105 pr_err("unable to allocate memory.\n");106 goto out;107 }108 109 if (fs64_to_cpu(sbi, sb1->sb_serial) >110 fs64_to_cpu(sbi, sb2->sb_serial)) {111 /* superblock #1 active */112 qnx6_mmi_copy_sb(qsb, sb1);113#ifdef CONFIG_QNX6FS_DEBUG114 qnx6_superblock_debug(qsb, s);115#endif116 memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));117 118 sbi->sb_buf = bh1;119 sbi->sb = (struct qnx6_super_block *)bh1->b_data;120 brelse(bh2);121 pr_info("superblock #1 active\n");122 } else {123 /* superblock #2 active */124 qnx6_mmi_copy_sb(qsb, sb2);125#ifdef CONFIG_QNX6FS_DEBUG126 qnx6_superblock_debug(qsb, s);127#endif128 memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));129 130 sbi->sb_buf = bh2;131 sbi->sb = (struct qnx6_super_block *)bh2->b_data;132 brelse(bh1);133 pr_info("superblock #2 active\n");134 }135 kfree(qsb);136 137 /* offset for mmi_fs is just SUPERBLOCK_AREA bytes */138 sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;139 140 /* success */141 return sbi->sb;142 143out:144 if (bh1 != NULL)145 brelse(bh1);146 if (bh2 != NULL)147 brelse(bh2);148 return NULL;149}150