1 files changed, 354 insertions, 0 deletions
diff --git a/fs/efs/super.c b/fs/efs/super.c
new file mode 100644
index 000000000..6ffb7ba15
--- /dev/null
+++ b/fs/efs/super.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * super.c
+ *
+ * Copyright (c) 1999 Al Smith
+ *
+ * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/exportfs.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+
+#include "efs.h"
+#include <linux/efs_vh.h>
+#include <linux/efs_fs_sb.h>
+
+static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int efs_fill_super(struct super_block *s, void *d, int silent);
+
+static struct dentry *efs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
+}
+
+static void efs_kill_sb(struct super_block *s)
+{
+	struct efs_sb_info *sbi = SUPER_INFO(s);
+	kill_block_super(s);
+	kfree(sbi);
+}
+
+static struct file_system_type efs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "efs",
+	.mount		= efs_mount,
+	.kill_sb	= efs_kill_sb,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("efs");
+
+static struct pt_types sgi_pt_types[] = {
+	{0x00,		"SGI vh"},
+	{0x01,		"SGI trkrepl"},
+	{0x02,		"SGI secrepl"},
+	{0x03,		"SGI raw"},
+	{0x04,		"SGI bsd"},
+	{SGI_SYSV,	"SGI sysv"},
+	{0x06,		"SGI vol"},
+	{SGI_EFS,	"SGI efs"},
+	{0x08,		"SGI lv"},
+	{0x09,		"SGI rlv"},
+	{0x0A,		"SGI xfs"},
+	{0x0B,		"SGI xfslog"},
+	{0x0C,		"SGI xlv"},
+	{0x82,		"Linux swap"},
+	{0x83,		"Linux native"},
+	{0,		NULL}
+};
+
+
+static struct kmem_cache * efs_inode_cachep;
+
+static struct inode *efs_alloc_inode(struct super_block *sb)
+{
+	struct efs_inode_info *ei;
+	ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void efs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
+}
+
+static void efs_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, efs_i_callback);
+}
+
+static void init_once(void *foo)
+{
+	struct efs_inode_info *ei = (struct efs_inode_info *) foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	efs_inode_cachep = kmem_cache_create("efs_inode_cache",
+				sizeof(struct efs_inode_info), 0,
+				SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
+				SLAB_ACCOUNT, init_once);
+	if (efs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(efs_inode_cachep);
+}
+
+static int efs_remount(struct super_block *sb, int *flags, char *data)
+{
+	sync_filesystem(sb);
+	*flags |= SB_RDONLY;
+	return 0;
+}
+
+static const struct super_operations efs_superblock_operations = {
+	.alloc_inode	= efs_alloc_inode,
+	.destroy_inode	= efs_destroy_inode,
+	.statfs		= efs_statfs,
+	.remount_fs	= efs_remount,
+};
+
+static const struct export_operations efs_export_ops = {
+	.fh_to_dentry	= efs_fh_to_dentry,
+	.fh_to_parent	= efs_fh_to_parent,
+	.get_parent	= efs_get_parent,
+};
+
+static int __init init_efs_fs(void) {
+	int err;
+	pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
+	err = init_inodecache();
+	if (err)
+		goto out1;
+	err = register_filesystem(&efs_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+out1:
+	return err;
+}
+
+static void __exit exit_efs_fs(void) {
+	unregister_filesystem(&efs_fs_type);
+	destroy_inodecache();
+}
+
+module_init(init_efs_fs)
+module_exit(exit_efs_fs)
+
+static efs_block_t efs_validate_vh(struct volume_header *vh) {
+	int		i;
+	__be32		cs, *ui;
+	int		csum;
+	efs_block_t	sblock = 0; /* shuts up gcc */
+	struct pt_types	*pt_entry;
+	int		pt_type, slice = -1;
+
+	if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
+		/*
+		 * assume that we're dealing with a partition and allow
+		 * read_super() to try and detect a valid superblock
+		 * on the next block.
+		 */
+		return 0;
+	}
+
+	ui = ((__be32 *) (vh + 1)) - 1;
+	for(csum = 0; ui >= ((__be32 *) vh);) {
+		cs = *ui--;
+		csum += be32_to_cpu(cs);
+	}
+	if (csum) {
+		pr_warn("SGI disklabel: checksum bad, label corrupted\n");
+		return 0;
+	}
+
+#ifdef DEBUG
+	pr_debug("bf: \"%16s\"\n", vh->vh_bootfile);
+
+	for(i = 0; i < NVDIR; i++) {
+		int	j;
+		char	name[VDNAMESIZE+1];
+
+		for(j = 0; j < VDNAMESIZE; j++) {
+			name[j] = vh->vh_vd[i].vd_name[j];
+		}
+		name[j] = (char) 0;
+
+		if (name[0]) {
+			pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n",
+				name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
+				(int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
+		}
+	}
+#endif
+
+	for(i = 0; i < NPARTAB; i++) {
+		pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
+		for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
+			if (pt_type == pt_entry->pt_type) break;
+		}
+#ifdef DEBUG
+		if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
+			pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
+				 i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
+				 (int)be32_to_cpu(vh->vh_pt[i].pt_nblks),
+				 pt_type, (pt_entry->pt_name) ?
+				 pt_entry->pt_name : "unknown");
+		}
+#endif
+		if (IS_EFS(pt_type)) {
+			sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
+			slice = i;
+		}
+	}
+
+	if (slice == -1) {
+		pr_notice("partition table contained no EFS partitions\n");
+#ifdef DEBUG
+	} else {
+		pr_info("using slice %d (type %s, offset 0x%x)\n", slice,
+			(pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
+			sblock);
+#endif
+	}
+	return sblock;
+}
+
+static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
+
+	if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
+		return -1;
+
+	sb->fs_magic     = be32_to_cpu(super->fs_magic);
+	sb->total_blocks = be32_to_cpu(super->fs_size);
+	sb->first_block  = be32_to_cpu(super->fs_firstcg);
+	sb->group_size   = be32_to_cpu(super->fs_cgfsize);
+	sb->data_free    = be32_to_cpu(super->fs_tfree);
+	sb->inode_free   = be32_to_cpu(super->fs_tinode);
+	sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
+	sb->total_groups = be16_to_cpu(super->fs_ncg);
+    
+	return 0;    
+}
+
+static int efs_fill_super(struct super_block *s, void *d, int silent)
+{
+	struct efs_sb_info *sb;
+	struct buffer_head *bh;
+	struct inode *root;
+
+ 	sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
+	if (!sb)
+		return -ENOMEM;
+	s->s_fs_info = sb;
+ 
+	s->s_magic		= EFS_SUPER_MAGIC;
+	if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
+		pr_err("device does not support %d byte blocks\n",
+			EFS_BLOCKSIZE);
+		return -EINVAL;
+	}
+  
+	/* read the vh (volume header) block */
+	bh = sb_bread(s, 0);
+
+	if (!bh) {
+		pr_err("cannot read volume header\n");
+		return -EIO;
+	}
+
+	/*
+	 * if this returns zero then we didn't find any partition table.
+	 * this isn't (yet) an error - just assume for the moment that
+	 * the device is valid and go on to search for a superblock.
+	 */
+	sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
+	brelse(bh);
+
+	if (sb->fs_start == -1) {
+		return -EINVAL;
+	}
+
+	bh = sb_bread(s, sb->fs_start + EFS_SUPER);
+	if (!bh) {
+		pr_err("cannot read superblock\n");
+		return -EIO;
+	}
+		
+	if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
+#ifdef DEBUG
+		pr_warn("invalid superblock at block %u\n",
+			sb->fs_start + EFS_SUPER);
+#endif
+		brelse(bh);
+		return -EINVAL;
+	}
+	brelse(bh);
+
+	if (!sb_rdonly(s)) {
+#ifdef DEBUG
+		pr_info("forcing read-only mode\n");
+#endif
+		s->s_flags |= SB_RDONLY;
+	}
+	s->s_op   = &efs_superblock_operations;
+	s->s_export_op = &efs_export_ops;
+	root = efs_iget(s, EFS_ROOTINODE);
+	if (IS_ERR(root)) {
+		pr_err("get root inode failed\n");
+		return PTR_ERR(root);
+	}
+
+	s->s_root = d_make_root(root);
+	if (!(s->s_root)) {
+		pr_err("get root dentry failed\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
+	struct super_block *sb = dentry->d_sb;
+	struct efs_sb_info *sbi = SUPER_INFO(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type    = EFS_SUPER_MAGIC;	/* efs magic number */
+	buf->f_bsize   = EFS_BLOCKSIZE;		/* blocksize */
+	buf->f_blocks  = sbi->total_groups *	/* total data blocks */
+			(sbi->group_size - sbi->inode_blocks);
+	buf->f_bfree   = sbi->data_free;	/* free data blocks */
+	buf->f_bavail  = sbi->data_free;	/* free blocks for non-root */
+	buf->f_files   = sbi->total_groups *	/* total inodes */
+			sbi->inode_blocks *
+			(EFS_BLOCKSIZE / sizeof(struct efs_dinode));
+	buf->f_ffree   = sbi->inode_free;	/* free inodes */
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+	buf->f_namelen = EFS_MAXNAMELEN;	/* max filename length */
+
+	return 0;
+}
+