[linux.git] / fs / qnx6 / super_mmi.c

/*
 * QNX6 file system, Linux implementation.
 *
 * Version : 1.0.0
 *
 * History :
 *
 * 01-02-2012 by Kai Bankett ([email protected]) : 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;
}
Commit	Line	Data
5d026c72 KB	1	/*
	2	* QNX6 file system, Linux implementation.
	3	*
	4	* Version : 1.0.0
	5	*
	6	* History :
	7	*
	8	* 01-02-2012 by Kai Bankett ([email protected]) : first release.
	9	*
	10	*/
	11
	12	#include <linux/buffer_head.h>
	13	#include <linux/slab.h>
	14	#include <linux/crc32.h>
	15	#include "qnx6.h"
	16
	17	static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,
	18	struct qnx6_mmi_super_block *sb)
	19	{
	20	qsb->sb_magic = sb->sb_magic;
	21	qsb->sb_checksum = sb->sb_checksum;
	22	qsb->sb_serial = sb->sb_serial;
	23	qsb->sb_blocksize = sb->sb_blocksize;
	24	qsb->sb_num_inodes = sb->sb_num_inodes;
	25	qsb->sb_free_inodes = sb->sb_free_inodes;
	26	qsb->sb_num_blocks = sb->sb_num_blocks;
	27	qsb->sb_free_blocks = sb->sb_free_blocks;
	28
	29	/* the rest of the superblock is the same */
	30	memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));
	31	memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));
	32	memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));
	33	}
	34
	35	struct qnx6_super_block qnx6_mmi_fill_super(struct super_block s, int silent)
	36	{
	37	struct buffer_head bh1, bh2 = NULL;
	38	struct qnx6_mmi_super_block sb1, sb2;
	39	struct qnx6_super_block *qsb = NULL;
	40	struct qnx6_sb_info *sbi;
	41	__u64 offset;
	42
	43	/* Check the superblock signatures
	44	start with the first superblock */
	45	bh1 = sb_bread(s, 0);
	46	if (!bh1) {
	47	printk(KERN_ERR "qnx6: Unable to read first mmi superblock\n");
	48	return NULL;
	49	}
	50	sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
	51	sbi = QNX6_SB(s);
	52	if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {
	53	if (!silent) {
	54	printk(KERN_ERR "qnx6: wrong signature (magic) in"
	55	" 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	printk(KERN_ERR "qnx6: 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	printk(KERN_ERR "qnx6: 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	printk(KERN_ERR "qnx6: 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	printk(KERN_ERR "qnx6: wrong signature (magic) in"
93	" superblock #2.\n");
94	goto out;
95	}
96
97	/* checksum check - start at byte 8 and end at byte 512 */
98	if (fs32_to_cpu(sbi, sb2->sb_checksum)
99	!= crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
100	printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
101	goto out;
102	}
103
104	qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
105	if (!qsb) {
106	printk(KERN_ERR "qnx6: unable to allocate memory.\n");
107	goto out;
108	}
109
110	if (fs64_to_cpu(sbi, sb1->sb_serial) >
111	fs64_to_cpu(sbi, sb2->sb_serial)) {
112	/* superblock #1 active */
113	qnx6_mmi_copy_sb(qsb, sb1);
114	#ifdef CONFIG_QNX6FS_DEBUG
115	qnx6_superblock_debug(qsb, s);
116	#endif
117	memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));
118
119	sbi->sb_buf = bh1;
120	sbi->sb = (struct qnx6_super_block *)bh1->b_data;
121	brelse(bh2);
122	printk(KERN_INFO "qnx6: superblock #1 active\n");
123	} else {
124	/* superblock #2 active */
125	qnx6_mmi_copy_sb(qsb, sb2);
126	#ifdef CONFIG_QNX6FS_DEBUG
127	qnx6_superblock_debug(qsb, s);
128	#endif
129	memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));
130
131	sbi->sb_buf = bh2;
132	sbi->sb = (struct qnx6_super_block *)bh2->b_data;
133	brelse(bh1);
134	printk(KERN_INFO "qnx6: superblock #2 active\n");
135	}
136	kfree(qsb);
137
138	/* offset for mmi_fs is just SUPERBLOCK_AREA bytes */
139	sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;
140
141	/* success */
142	return sbi->sb;
143
144	out:
145	if (bh1 != NULL)
146	brelse(bh1);
147	if (bh2 != NULL)
148	brelse(bh2);
149	return NULL;
150	}