Al Smith's new EFS code, which seems to work and things (missed one)

1 files changed, 232 insertions, 0 deletions

diff --git a/fs/efs/super.c b/fs/efs/super.c
new file mode 100644
index 000000000..f897a2ebb
--- /dev/null
+++ b/fs/efs/super.c
@@ -0,0 +1,232 @@
+/*
+ * super.c
+ *
+ * Copyright (c) 1999 Al Smith
+ *
+ * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
+ */
+
+#include <linux/module.h>
+#include <linux/efs.h>
+
+void			efs_read_inode(struct inode *);
+void			efs_put_super(struct super_block *);
+int			efs_statfs(struct super_block *, struct statfs *, int);
+struct super_block *	efs_read_super(struct super_block *, void *, int);
+
+static struct file_system_type efs_fs_type = {
+	"efs",			/* filesystem name */
+	FS_REQUIRES_DEV,	/* fs_flags */
+	efs_read_super,		/* entry function pointer */
+	NULL 			/* next */
+};
+
+static struct super_operations efs_superblock_operations = {
+	efs_read_inode,	/* read_inode */
+	NULL,		/* write_inode */
+	NULL,		/* put_inode */
+	NULL,		/* delete_inode */
+	NULL,		/* notify_change */
+	efs_put_super,	/* put_super */
+	NULL,		/* write_super */
+	efs_statfs,	/* statfs */
+	NULL		/* remount */
+};
+
+int init_module(void) {
+	return register_filesystem(&efs_fs_type);
+}
+
+void cleanup_module(void) {
+	unregister_filesystem(&efs_fs_type);
+}
+
+static long efs_validate_vh(struct volume_header *vh, int slice) {
+	int	i, j;
+	int32_t	sblock = 0;
+	int	type;
+	char	name[VDNAMESIZE+1];
+
+	if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
+		printk("EFS: invalid volume descriptor\n");
+		return 0;
+	}
+
+#ifdef DEBUG
+	printk("EFS: bf: %16s\n", vh->vh_bootfile);
+#endif
+
+	for(i = 0; i < NVDIR; i++) {
+		for(j = 0; j < VDNAMESIZE; j++) {
+			name[j] = vh->vh_vd[i].vd_name[j];
+		}
+		name[j] = (char) 0;
+
+#ifdef DEBUG
+		if (name[0]) {
+			printk("EFS: vh: 0x%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++) {
+		type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
+#ifdef DEBUG
+		printk("EFS: pt: start: %08d size: %08d type: %08d\n",
+			(int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
+			(int) be32_to_cpu(vh->vh_pt[i].pt_nblks),
+			type);
+#endif
+		if (slice == i && (type == 5 || type == 7)) {
+			sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
+		} else if (slice == -1 && sblock == 0) {
+			if (type == 5 || type == 7) {
+				sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
+				slice = i;
+			}
+		}
+	}
+
+	if (sblock) {
+		printk("EFS: using slice %d (offset 0x%x)\n", slice, sblock);
+	} else if (slice != -1) {
+		printk("EFS: no efs filesystem found on slice %d\n", slice);
+	}
+	return(sblock);
+}
+
+static int efs_validate_super(struct efs_spb *sb, struct efs *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->inode_blocks = be16_to_cpu(super->fs_cgisize);
+	sb->total_groups = be16_to_cpu(super->fs_ncg);
+    
+	return 0;    
+}
+
+struct super_block *efs_read_super(struct super_block *s, void *d, int verbose) {
+	int slice = -1;
+	kdev_t dev = s->s_dev;
+	struct inode *root_inode;
+	struct efs_spb *spb;
+	struct buffer_head *bh;
+
+	if (d) {
+		/* parse mount option */
+		if (!strncmp(d, "slice=", 6)) {
+			slice = simple_strtoul(d+6, NULL, 10);
+		} else if (strcmp(d, "")) {
+			printk("EFS: invalid mount option\n");
+			return(NULL);
+		}
+	}
+
+	MOD_INC_USE_COUNT;
+	lock_super(s);
+  
+	/* approx 230 bytes available in this union */
+ 	spb = (struct efs_spb *) &(s->u.generic_sbp);
+
+	set_blocksize(dev, EFS_BLOCKSIZE);
+  
+	/* read the vh (volume header) block */
+	bh = bread(dev, 0, EFS_BLOCKSIZE);
+
+	if (!bh) {
+		printk("EFS: cannot read volume header\n");
+		goto out_no_fs_ul;
+	}
+
+	spb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data, slice);
+	brelse(bh);
+
+	if(!spb->fs_start) {
+		printk("EFS: invalid volume descriptor\n");
+		goto out_no_fs_ul;
+	}
+
+	bh = bread(dev, spb->fs_start + EFS_SUPER, EFS_BLOCKSIZE);
+	if (!bh) {
+		printk("EFS: unable to read superblock\n");
+		goto out_no_fs_ul;
+	}
+		
+	if (efs_validate_super(spb, (struct efs *) bh->b_data)) {
+		printk("EFS: invalid superblock\n");
+		brelse(bh);
+		goto out_no_fs_ul;
+	}
+  
+	s->s_magic		= EFS_SUPER_MAGIC;
+	s->s_blocksize		= EFS_BLOCKSIZE;
+	s->s_blocksize_bits	= EFS_BLOCKSIZE_BITS;
+	if (!(s->s_flags & MS_RDONLY)) {
+#ifdef DEBUG
+		printk("EFS: forcing read-only: RW access not supported\n");
+#endif
+		s->s_flags |= MS_RDONLY;
+	}
+	s->s_op			= &efs_superblock_operations;
+	s->s_dev		= dev;
+	s->s_root		= NULL;
+
+	root_inode = iget(s, EFS_ROOTINODE);
+	if (root_inode) {
+		s->s_root = d_alloc_root(root_inode, NULL);
+		if (!(s->s_root)) {
+			iput(root_inode);
+		}
+	}
+	unlock_super(s);
+  
+	if(!(s->s_root)) {
+		printk("EFS: not mounted\n");
+		goto out_no_fs;
+	}
+
+	if(check_disk_change(s->s_dev)) {
+		printk("EFS: device changed\n");
+		goto out_no_fs;
+	}
+
+	return(s);
+
+out_no_fs_ul:
+	unlock_super(s);
+out_no_fs:
+	s->s_dev = 0;
+	MOD_DEC_USE_COUNT;
+	return(NULL);
+}
+
+void efs_put_super(struct super_block *s) {
+	s->s_dev = 0;
+	MOD_DEC_USE_COUNT;
+}
+
+int efs_statfs(struct super_block *s, struct statfs *buf, int bufsiz) {
+	struct statfs tmp;
+	struct efs_spb *sbp = (struct efs_spb *)&s->u.generic_sbp;
+
+	tmp.f_type    = EFS_SUPER_MAGIC;
+	tmp.f_bsize   = EFS_BLOCKSIZE;
+	tmp.f_blocks  = sbp->total_blocks;
+	tmp.f_bfree   = 0;
+	tmp.f_bavail  = 0;
+	tmp.f_files   = 0; /* ? */
+	tmp.f_ffree   = 0;
+	tmp.f_fsid.val[0] = (sbp->fs_magic >> 16) & 0xffff;
+	tmp.f_fsid.val[1] =  sbp->fs_magic        & 0xffff;
+	tmp.f_namelen = EFS_MAXNAMELEN;
+
+	return copy_to_user(buf, &tmp, bufsiz) ? -EFAULT : 0;
+}
+