--- /dev/null
+/*
+ * 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->s_flags & MS_RDONLY)) {
+ 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_truncate = 1;
+ 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 |= MS_RDONLY;
+ if (sbi->s_truncate)
+ sb->s_d_op = &sysv_dentry_operations;
+ 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_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_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");
Code Review / kvmfornfv.git / blobdiff