1 files changed, 594 insertions, 0 deletions

diff --git a/fs/sysv/super.c b/fs/sysv/super.c
new file mode 100644
index 000000000..cc8e2ed15
--- /dev/null
+++ b/fs/sysv/super.c
@@ -0,0 +1,594 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/sysv/inode.c
+ *
+ *  minix/inode.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  xenix/inode.c
+ *  Copyright (C) 1992  Doug Evans
+ *
+ *  coh/inode.c
+ *  Copyright (C) 1993  Pascal Haible, Bruno Haible
+ *
+ *  sysv/inode.c
+ *  Copyright (C) 1993  Paul B. Monday
+ *
+ *  sysv/inode.c
+ *  Copyright (C) 1993  Bruno Haible
+ *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
+ *
+ *  This file contains code for read/parsing the superblock.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include "sysv.h"
+
+/*
+ * The following functions try to recognize specific filesystems.
+ *
+ * We recognize:
+ * - Xenix FS by its magic number.
+ * - SystemV FS by its magic number.
+ * - Coherent FS by its funny fname/fpack field.
+ * - SCO AFS by s_nfree == 0xffff
+ * - V7 FS has no distinguishing features.
+ *
+ * We discriminate among SystemV4 and SystemV2 FS by the assumption that
+ * the time stamp is not < 01-01-1980.
+ */
+
+enum {
+	JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60
+};
+
+static void detected_xenix(struct sysv_sb_info *sbi, unsigned *max_links)
+{
+	struct buffer_head *bh1 = sbi->s_bh1;
+	struct buffer_head *bh2 = sbi->s_bh2;
+	struct xenix_super_block * sbd1;
+	struct xenix_super_block * sbd2;
+
+	if (bh1 != bh2)
+		sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
+	else {
+		/* block size = 512, so bh1 != bh2 */
+		sbd1 = (struct xenix_super_block *) bh1->b_data;
+		sbd2 = (struct xenix_super_block *) (bh2->b_data - 512);
+	}
+
+	*max_links = XENIX_LINK_MAX;
+	sbi->s_fic_size = XENIX_NICINOD;
+	sbi->s_flc_size = XENIX_NICFREE;
+	sbi->s_sbd1 = (char *)sbd1;
+	sbi->s_sbd2 = (char *)sbd2;
+	sbi->s_sb_fic_count = &sbd1->s_ninode;
+	sbi->s_sb_fic_inodes = &sbd1->s_inode[0];
+	sbi->s_sb_total_free_inodes = &sbd2->s_tinode;
+	sbi->s_bcache_count = &sbd1->s_nfree;
+	sbi->s_bcache = &sbd1->s_free[0];
+	sbi->s_free_blocks = &sbd2->s_tfree;
+	sbi->s_sb_time = &sbd2->s_time;
+	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd1->s_isize);
+	sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize);
+}
+
+static void detected_sysv4(struct sysv_sb_info *sbi, unsigned *max_links)
+{
+	struct sysv4_super_block * sbd;
+	struct buffer_head *bh1 = sbi->s_bh1;
+	struct buffer_head *bh2 = sbi->s_bh2;
+
+	if (bh1 == bh2)
+		sbd = (struct sysv4_super_block *) (bh1->b_data + BLOCK_SIZE/2);
+	else
+		sbd = (struct sysv4_super_block *) bh2->b_data;
+
+	*max_links = SYSV_LINK_MAX;
+	sbi->s_fic_size = SYSV_NICINOD;
+	sbi->s_flc_size = SYSV_NICFREE;
+	sbi->s_sbd1 = (char *)sbd;
+	sbi->s_sbd2 = (char *)sbd;
+	sbi->s_sb_fic_count = &sbd->s_ninode;
+	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
+	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
+	sbi->s_bcache_count = &sbd->s_nfree;
+	sbi->s_bcache = &sbd->s_free[0];
+	sbi->s_free_blocks = &sbd->s_tfree;
+	sbi->s_sb_time = &sbd->s_time;
+	sbi->s_sb_state = &sbd->s_state;
+	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
+	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
+}
+
+static void detected_sysv2(struct sysv_sb_info *sbi, unsigned *max_links)
+{
+	struct sysv2_super_block *sbd;
+	struct buffer_head *bh1 = sbi->s_bh1;
+	struct buffer_head *bh2 = sbi->s_bh2;
+
+	if (bh1 == bh2)
+		sbd = (struct sysv2_super_block *) (bh1->b_data + BLOCK_SIZE/2);
+	else
+		sbd = (struct sysv2_super_block *) bh2->b_data;
+
+	*max_links = SYSV_LINK_MAX;
+	sbi->s_fic_size = SYSV_NICINOD;
+	sbi->s_flc_size = SYSV_NICFREE;
+	sbi->s_sbd1 = (char *)sbd;
+	sbi->s_sbd2 = (char *)sbd;
+	sbi->s_sb_fic_count = &sbd->s_ninode;
+	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
+	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
+	sbi->s_bcache_count = &sbd->s_nfree;
+	sbi->s_bcache = &sbd->s_free[0];
+	sbi->s_free_blocks = &sbd->s_tfree;
+	sbi->s_sb_time = &sbd->s_time;
+	sbi->s_sb_state = &sbd->s_state;
+	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
+	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
+}
+
+static void detected_coherent(struct sysv_sb_info *sbi, unsigned *max_links)
+{
+	struct coh_super_block * sbd;
+	struct buffer_head *bh1 = sbi->s_bh1;
+
+	sbd = (struct coh_super_block *) bh1->b_data;
+
+	*max_links = COH_LINK_MAX;
+	sbi->s_fic_size = COH_NICINOD;
+	sbi->s_flc_size = COH_NICFREE;
+	sbi->s_sbd1 = (char *)sbd;
+	sbi->s_sbd2 = (char *)sbd;
+	sbi->s_sb_fic_count = &sbd->s_ninode;
+	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
+	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
+	sbi->s_bcache_count = &sbd->s_nfree;
+	sbi->s_bcache = &sbd->s_free[0];
+	sbi->s_free_blocks = &sbd->s_tfree;
+	sbi->s_sb_time = &sbd->s_time;
+	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
+	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
+}
+
+static void detected_v7(struct sysv_sb_info *sbi, unsigned *max_links)
+{
+	struct buffer_head *bh2 = sbi->s_bh2;
+	struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data;
+
+	*max_links = V7_LINK_MAX;
+	sbi->s_fic_size = V7_NICINOD;
+	sbi->s_flc_size = V7_NICFREE;
+	sbi->s_sbd1 = (char *)sbd;
+	sbi->s_sbd2 = (char *)sbd;
+	sbi->s_sb_fic_count = &sbd->s_ninode;
+	sbi->s_sb_fic_inodes = &sbd->s_inode[0];
+	sbi->s_sb_total_free_inodes = &sbd->s_tinode;
+	sbi->s_bcache_count = &sbd->s_nfree;
+	sbi->s_bcache = &sbd->s_free[0];
+	sbi->s_free_blocks = &sbd->s_tfree;
+	sbi->s_sb_time = &sbd->s_time;
+	sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
+	sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
+}
+
+static int detect_xenix(struct sysv_sb_info *sbi, struct buffer_head *bh)
+{
+	struct xenix_super_block *sbd = (struct xenix_super_block *)bh->b_data;
+	if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0x2b5544))
+		sbi->s_bytesex = BYTESEX_LE;
+	else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0x2b5544))
+		sbi->s_bytesex = BYTESEX_BE;
+	else
+		return 0;
+	switch (fs32_to_cpu(sbi, sbd->s_type)) {
+	case 1:
+		sbi->s_type = FSTYPE_XENIX;
+		return 1;
+	case 2:
+		sbi->s_type = FSTYPE_XENIX;
+		return 2;
+	default:
+		return 0;
+	}
+}
+
+static int detect_sysv(struct sysv_sb_info *sbi, struct buffer_head *bh)
+{
+	struct super_block *sb = sbi->s_sb;
+	/* All relevant fields are at the same offsets in R2 and R4 */
+	struct sysv4_super_block * sbd;
+	u32 type;
+
+	sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
+	if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0xfd187e20))
+		sbi->s_bytesex = BYTESEX_LE;
+	else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0xfd187e20))
+		sbi->s_bytesex = BYTESEX_BE;
+	else
+		return 0;
+
+	type = fs32_to_cpu(sbi, sbd->s_type);
+ 
+ 	if (fs16_to_cpu(sbi, sbd->s_nfree) == 0xffff) {
+ 		sbi->s_type = FSTYPE_AFS;
+		sbi->s_forced_ro = 1;
+ 		if (!sb_rdonly(sb)) {
+ 			printk("SysV FS: SCO EAFS on %s detected, " 
+ 				"forcing read-only mode.\n", 
+ 				sb->s_id);
+ 		}
+ 		return type;
+ 	}
+ 
+	if (fs32_to_cpu(sbi, sbd->s_time) < JAN_1_1980) {
+		/* this is likely to happen on SystemV2 FS */
+		if (type > 3 || type < 1)
+			return 0;
+		sbi->s_type = FSTYPE_SYSV2;
+		return type;
+	}
+	if ((type > 3 || type < 1) && (type > 0x30 || type < 0x10))
+		return 0;
+
+	/* On Interactive Unix (ISC) Version 4.0/3.x s_type field = 0x10,
+	   0x20 or 0x30 indicates that symbolic links and the 14-character
+	   filename limit is gone. Due to lack of information about this
+           feature read-only mode seems to be a reasonable approach... -KGB */
+
+	if (type >= 0x10) {
+		printk("SysV FS: can't handle long file names on %s, "
+		       "forcing read-only mode.\n", sb->s_id);
+		sbi->s_forced_ro = 1;
+	}
+
+	sbi->s_type = FSTYPE_SYSV4;
+	return type >= 0x10 ? type >> 4 : type;
+}
+
+static int detect_coherent(struct sysv_sb_info *sbi, struct buffer_head *bh)
+{
+	struct coh_super_block * sbd;
+
+	sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
+	if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
+	    || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
+		return 0;
+	sbi->s_bytesex = BYTESEX_PDP;
+	sbi->s_type = FSTYPE_COH;
+	return 1;
+}
+
+static int detect_sysv_odd(struct sysv_sb_info *sbi, struct buffer_head *bh)
+{
+	int size = detect_sysv(sbi, bh);
+
+	return size>2 ? 0 : size;
+}
+
+static struct {
+	int block;
+	int (*test)(struct sysv_sb_info *, struct buffer_head *);
+} flavours[] = {
+	{1, detect_xenix},
+	{0, detect_sysv},
+	{0, detect_coherent},
+	{9, detect_sysv_odd},
+	{15,detect_sysv_odd},
+	{18,detect_sysv},
+};
+
+static char *flavour_names[] = {
+	[FSTYPE_XENIX]	= "Xenix",
+	[FSTYPE_SYSV4]	= "SystemV",
+	[FSTYPE_SYSV2]	= "SystemV Release 2",
+	[FSTYPE_COH]	= "Coherent",
+	[FSTYPE_V7]	= "V7",
+	[FSTYPE_AFS]	= "AFS",
+};
+
+static void (*flavour_setup[])(struct sysv_sb_info *, unsigned *) = {
+	[FSTYPE_XENIX]	= detected_xenix,
+	[FSTYPE_SYSV4]	= detected_sysv4,
+	[FSTYPE_SYSV2]	= detected_sysv2,
+	[FSTYPE_COH]	= detected_coherent,
+	[FSTYPE_V7]	= detected_v7,
+	[FSTYPE_AFS]	= detected_sysv4,
+};
+
+static int complete_read_super(struct super_block *sb, int silent, int size)
+{
+	struct sysv_sb_info *sbi = SYSV_SB(sb);
+	struct inode *root_inode;
+	char *found = flavour_names[sbi->s_type];
+	u_char n_bits = size+8;
+	int bsize = 1 << n_bits;
+	int bsize_4 = bsize >> 2;
+
+	sbi->s_firstinodezone = 2;
+
+	flavour_setup[sbi->s_type](sbi, &sb->s_max_links);
+	
+	sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
+	sbi->s_inodes_per_block = bsize >> 6;
+	sbi->s_inodes_per_block_1 = (bsize >> 6)-1;
+	sbi->s_inodes_per_block_bits = n_bits-6;
+	sbi->s_ind_per_block = bsize_4;
+	sbi->s_ind_per_block_2 = bsize_4*bsize_4;
+	sbi->s_toobig_block = 10 + bsize_4 * (1 + bsize_4 * (1 + bsize_4));
+	sbi->s_ind_per_block_bits = n_bits-2;
+
+	sbi->s_ninodes = (sbi->s_firstdatazone - sbi->s_firstinodezone)
+		<< sbi->s_inodes_per_block_bits;
+
+	if (!silent)
+		printk("VFS: Found a %s FS (block size = %ld) on device %s\n",
+		       found, sb->s_blocksize, sb->s_id);
+
+	sb->s_magic = SYSV_MAGIC_BASE + sbi->s_type;
+	/* set up enough so that it can read an inode */
+	sb->s_op = &sysv_sops;
+	if (sbi->s_forced_ro)
+		sb->s_flags |= SB_RDONLY;
+	root_inode = sysv_iget(sb, SYSV_ROOT_INO);
+	if (IS_ERR(root_inode)) {
+		printk("SysV FS: get root inode failed\n");
+		return 0;
+	}
+	sb->s_root = d_make_root(root_inode);
+	if (!sb->s_root) {
+		printk("SysV FS: get root dentry failed\n");
+		return 0;
+	}
+	return 1;
+}
+
+static int sysv_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct buffer_head *bh1, *bh = NULL;
+	struct sysv_sb_info *sbi;
+	unsigned long blocknr;
+	int size = 0, i;
+	
+	BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block));
+	BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block));
+	BUILD_BUG_ON(512 != sizeof (struct sysv2_super_block));
+	BUILD_BUG_ON(500 != sizeof (struct coh_super_block));
+	BUILD_BUG_ON(64 != sizeof (struct sysv_inode));
+
+	sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sbi->s_sb = sb;
+	sbi->s_block_base = 0;
+	mutex_init(&sbi->s_lock);
+	sb->s_fs_info = sbi;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
+	sb_set_blocksize(sb, BLOCK_SIZE);
+
+	for (i = 0; i < ARRAY_SIZE(flavours) && !size; i++) {
+		brelse(bh);
+		bh = sb_bread(sb, flavours[i].block);
+		if (!bh)
+			continue;
+		size = flavours[i].test(SYSV_SB(sb), bh);
+	}
+
+	if (!size)
+		goto Eunknown;
+
+	switch (size) {
+		case 1:
+			blocknr = bh->b_blocknr << 1;
+			brelse(bh);
+			sb_set_blocksize(sb, 512);
+			bh1 = sb_bread(sb, blocknr);
+			bh = sb_bread(sb, blocknr + 1);
+			break;
+		case 2:
+			bh1 = bh;
+			break;
+		case 3:
+			blocknr = bh->b_blocknr >> 1;
+			brelse(bh);
+			sb_set_blocksize(sb, 2048);
+			bh1 = bh = sb_bread(sb, blocknr);
+			break;
+		default:
+			goto Ebadsize;
+	}
+
+	if (bh && bh1) {
+		sbi->s_bh1 = bh1;
+		sbi->s_bh2 = bh;
+		if (complete_read_super(sb, silent, size))
+			return 0;
+	}
+
+	brelse(bh1);
+	brelse(bh);
+	sb_set_blocksize(sb, BLOCK_SIZE);
+	printk("oldfs: cannot read superblock\n");
+failed:
+	kfree(sbi);
+	return -EINVAL;
+
+Eunknown:
+	brelse(bh);
+	if (!silent)
+		printk("VFS: unable to find oldfs superblock on device %s\n",
+			sb->s_id);
+	goto failed;
+Ebadsize:
+	brelse(bh);
+	if (!silent)
+		printk("VFS: oldfs: unsupported block size (%dKb)\n",
+			1<<(size-2));
+	goto failed;
+}
+
+static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh)
+{
+	struct v7_super_block *v7sb;
+	struct sysv_inode *v7i;
+	struct buffer_head *bh2;
+	struct sysv_sb_info *sbi;
+
+	sbi = sb->s_fs_info;
+
+	/* plausibility check on superblock */
+	v7sb = (struct v7_super_block *) bh->b_data;
+	if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE ||
+	    fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD ||
+	    fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE)
+		return 0;
+
+	/* plausibility check on root inode: it is a directory,
+	   with a nonzero size that is a multiple of 16 */
+	bh2 = sb_bread(sb, 2);
+	if (bh2 == NULL)
+		return 0;
+
+	v7i = (struct sysv_inode *)(bh2->b_data + 64);
+	if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR ||
+	    (fs32_to_cpu(sbi, v7i->i_size) == 0) ||
+	    (fs32_to_cpu(sbi, v7i->i_size) & 017) ||
+	    (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES *
+	     sizeof(struct sysv_dir_entry))) {
+		brelse(bh2);
+		return 0;
+	}
+
+	brelse(bh2);
+	return 1;
+}
+
+static int v7_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct sysv_sb_info *sbi;
+	struct buffer_head *bh;
+
+	if (440 != sizeof (struct v7_super_block))
+		panic("V7 FS: bad super-block size");
+	if (64 != sizeof (struct sysv_inode))
+		panic("sysv fs: bad i-node size");
+
+	sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
+	if (!sbi)
+		return -ENOMEM;
+
+	sbi->s_sb = sb;
+	sbi->s_block_base = 0;
+	sbi->s_type = FSTYPE_V7;
+	mutex_init(&sbi->s_lock);
+	sb->s_fs_info = sbi;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
+	
+	sb_set_blocksize(sb, 512);
+
+	if ((bh = sb_bread(sb, 1)) == NULL) {
+		if (!silent)
+			printk("VFS: unable to read V7 FS superblock on "
+			       "device %s.\n", sb->s_id);
+		goto failed;
+	}
+
+	/* Try PDP-11 UNIX */
+	sbi->s_bytesex = BYTESEX_PDP;
+	if (v7_sanity_check(sb, bh))
+		goto detected;
+
+	/* Try PC/IX, v7/x86 */
+	sbi->s_bytesex = BYTESEX_LE;
+	if (v7_sanity_check(sb, bh))
+		goto detected;
+
+	goto failed;
+
+detected:
+	sbi->s_bh1 = bh;
+	sbi->s_bh2 = bh;
+	if (complete_read_super(sb, silent, 1))
+		return 0;
+
+failed:
+	printk(KERN_ERR "VFS: could not find a valid V7 on %s.\n",
+		sb->s_id);
+	brelse(bh);
+	kfree(sbi);
+	return -EINVAL;
+}
+
+/* Every kernel module contains stuff like this. */
+
+static struct dentry *sysv_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super);
+}
+
+static struct dentry *v7_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super);
+}
+
+static struct file_system_type sysv_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "sysv",
+	.mount		= sysv_mount,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("sysv");
+
+static struct file_system_type v7_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "v7",
+	.mount		= v7_mount,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("v7");
+MODULE_ALIAS("v7");
+
+static int __init init_sysv_fs(void)
+{
+	int error;
+
+	error = sysv_init_icache();
+	if (error)
+		goto out;
+	error = register_filesystem(&sysv_fs_type);
+	if (error)
+		goto destroy_icache;
+	error = register_filesystem(&v7_fs_type);
+	if (error)
+		goto unregister;
+	return 0;
+
+unregister:
+	unregister_filesystem(&sysv_fs_type);
+destroy_icache:
+	sysv_destroy_icache();
+out:
+	return error;
+}
+
+static void __exit exit_sysv_fs(void)
+{
+	unregister_filesystem(&sysv_fs_type);
+	unregister_filesystem(&v7_fs_type);
+	sysv_destroy_icache();
+}
+
+module_init(init_sysv_fs)
+module_exit(exit_sysv_fs)
+MODULE_LICENSE("GPL");