| /* |
| * 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/locks.h> |
| #include <linux/efs_fs.h> |
| #include <linux/efs_vh.h> |
| #include <linux/efs_fs_sb.h> |
| |
| static DECLARE_FSTYPE_DEV(efs_fs_type, "efs", efs_read_super); |
| |
| static struct super_operations efs_superblock_operations = { |
| read_inode: efs_read_inode, |
| statfs: efs_statfs, |
| }; |
| |
| static int __init init_efs_fs(void) { |
| printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); |
| return register_filesystem(&efs_fs_type); |
| } |
| |
| static void __exit exit_efs_fs(void) { |
| unregister_filesystem(&efs_fs_type); |
| } |
| |
| EXPORT_NO_SYMBOLS; |
| |
| module_init(init_efs_fs) |
| module_exit(exit_efs_fs) |
| |
| static efs_block_t efs_validate_vh(struct volume_header *vh) { |
| int i; |
| unsigned int cs, csum, *ui; |
| 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 = ((unsigned int *) (vh + 1)) - 1; |
| for(csum = 0; ui >= ((unsigned int *) vh);) { |
| cs = *ui--; |
| csum += be32_to_cpu(cs); |
| } |
| if (csum) { |
| printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); |
| return 0; |
| } |
| |
| #ifdef DEBUG |
| printk(KERN_DEBUG "EFS: 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]) { |
| printk(KERN_DEBUG "EFS: 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)) { |
| printk(KERN_DEBUG "EFS: 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) { |
| printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); |
| #ifdef DEBUG |
| } else { |
| printk(KERN_INFO "EFS: 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; |
| } |
| |
| struct super_block *efs_read_super(struct super_block *s, void *d, int silent) { |
| kdev_t dev = s->s_dev; |
| struct efs_sb_info *sb; |
| struct buffer_head *bh; |
| |
| sb = SUPER_INFO(s); |
| |
| s->s_magic = EFS_SUPER_MAGIC; |
| s->s_blocksize = EFS_BLOCKSIZE; |
| s->s_blocksize_bits = EFS_BLOCKSIZE_BITS; |
| set_blocksize(dev, EFS_BLOCKSIZE); |
| |
| /* read the vh (volume header) block */ |
| bh = sb_bread(s, 0); |
| |
| if (!bh) { |
| printk(KERN_ERR "EFS: cannot read volume header\n"); |
| goto out_no_fs_ul; |
| } |
| |
| /* |
| * 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) { |
| goto out_no_fs_ul; |
| } |
| |
| bh = sb_bread(s, sb->fs_start + EFS_SUPER); |
| if (!bh) { |
| printk(KERN_ERR "EFS: cannot read superblock\n"); |
| goto out_no_fs_ul; |
| } |
| |
| if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { |
| #ifdef DEBUG |
| printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); |
| #endif |
| brelse(bh); |
| goto out_no_fs_ul; |
| } |
| brelse(bh); |
| |
| if (!(s->s_flags & MS_RDONLY)) { |
| #ifdef DEBUG |
| printk(KERN_INFO "EFS: forcing read-only mode\n"); |
| #endif |
| s->s_flags |= MS_RDONLY; |
| } |
| s->s_op = &efs_superblock_operations; |
| s->s_root = d_alloc_root(iget(s, EFS_ROOTINODE)); |
| |
| if (!(s->s_root)) { |
| printk(KERN_ERR "EFS: get root inode failed\n"); |
| goto out_no_fs; |
| } |
| |
| return(s); |
| |
| out_no_fs_ul: |
| out_no_fs: |
| return(NULL); |
| } |
| |
| int efs_statfs(struct super_block *s, struct statfs *buf) { |
| struct efs_sb_info *sb = SUPER_INFO(s); |
| |
| buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ |
| buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ |
| buf->f_blocks = sb->total_groups * /* total data blocks */ |
| (sb->group_size - sb->inode_blocks); |
| buf->f_bfree = sb->data_free; /* free data blocks */ |
| buf->f_bavail = sb->data_free; /* free blocks for non-root */ |
| buf->f_files = sb->total_groups * /* total inodes */ |
| sb->inode_blocks * |
| (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); |
| buf->f_ffree = sb->inode_free; /* free inodes */ |
| buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */ |
| buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */ |
| buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ |
| |
| return 0; |
| } |
| |