1 /* 2 * super.c 3 * 4 * Copyright (c) 1999 Al Smith 5 * 6 * Portions derived from work (c) 1995,1996 Christian Vogelgsang. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/efs_fs.h> 12 #include <linux/efs_vh.h> 13 #include <linux/efs_fs_sb.h> 14 #include <linux/slab.h> 15 #include <linux/buffer_head.h> 16 #include <linux/vfs.h> 17 18 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); 19 static int efs_fill_super(struct super_block *s, void *d, int silent); 20 21 static int efs_get_sb(struct file_system_type *fs_type, 22 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 23 { 24 return get_sb_bdev(fs_type, flags, dev_name, data, efs_fill_super, mnt); 25 } 26 27 static struct file_system_type efs_fs_type = { 28 .owner = THIS_MODULE, 29 .name = "efs", 30 .get_sb = efs_get_sb, 31 .kill_sb = kill_block_super, 32 .fs_flags = FS_REQUIRES_DEV, 33 }; 34 35 static struct pt_types sgi_pt_types[] = { 36 {0x00, "SGI vh"}, 37 {0x01, "SGI trkrepl"}, 38 {0x02, "SGI secrepl"}, 39 {0x03, "SGI raw"}, 40 {0x04, "SGI bsd"}, 41 {SGI_SYSV, "SGI sysv"}, 42 {0x06, "SGI vol"}, 43 {SGI_EFS, "SGI efs"}, 44 {0x08, "SGI lv"}, 45 {0x09, "SGI rlv"}, 46 {0x0A, "SGI xfs"}, 47 {0x0B, "SGI xfslog"}, 48 {0x0C, "SGI xlv"}, 49 {0x82, "Linux swap"}, 50 {0x83, "Linux native"}, 51 {0, NULL} 52 }; 53 54 55 static struct kmem_cache * efs_inode_cachep; 56 57 static struct inode *efs_alloc_inode(struct super_block *sb) 58 { 59 struct efs_inode_info *ei; 60 ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 61 if (!ei) 62 return NULL; 63 return &ei->vfs_inode; 64 } 65 66 static void efs_destroy_inode(struct inode *inode) 67 { 68 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 69 } 70 71 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 72 { 73 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 74 75 inode_init_once(&ei->vfs_inode); 76 } 77 78 static int init_inodecache(void) 79 { 80 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 81 sizeof(struct efs_inode_info), 82 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 83 init_once, NULL); 84 if (efs_inode_cachep == NULL) 85 return -ENOMEM; 86 return 0; 87 } 88 89 static void destroy_inodecache(void) 90 { 91 kmem_cache_destroy(efs_inode_cachep); 92 } 93 94 static void efs_put_super(struct super_block *s) 95 { 96 kfree(s->s_fs_info); 97 s->s_fs_info = NULL; 98 } 99 100 static int efs_remount(struct super_block *sb, int *flags, char *data) 101 { 102 *flags |= MS_RDONLY; 103 return 0; 104 } 105 106 static const struct super_operations efs_superblock_operations = { 107 .alloc_inode = efs_alloc_inode, 108 .destroy_inode = efs_destroy_inode, 109 .read_inode = efs_read_inode, 110 .put_super = efs_put_super, 111 .statfs = efs_statfs, 112 .remount_fs = efs_remount, 113 }; 114 115 static struct export_operations efs_export_ops = { 116 .get_parent = efs_get_parent, 117 }; 118 119 static int __init init_efs_fs(void) { 120 int err; 121 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 122 err = init_inodecache(); 123 if (err) 124 goto out1; 125 err = register_filesystem(&efs_fs_type); 126 if (err) 127 goto out; 128 return 0; 129 out: 130 destroy_inodecache(); 131 out1: 132 return err; 133 } 134 135 static void __exit exit_efs_fs(void) { 136 unregister_filesystem(&efs_fs_type); 137 destroy_inodecache(); 138 } 139 140 module_init(init_efs_fs) 141 module_exit(exit_efs_fs) 142 143 static efs_block_t efs_validate_vh(struct volume_header *vh) { 144 int i; 145 __be32 cs, *ui; 146 int csum; 147 efs_block_t sblock = 0; /* shuts up gcc */ 148 struct pt_types *pt_entry; 149 int pt_type, slice = -1; 150 151 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 152 /* 153 * assume that we're dealing with a partition and allow 154 * read_super() to try and detect a valid superblock 155 * on the next block. 156 */ 157 return 0; 158 } 159 160 ui = ((__be32 *) (vh + 1)) - 1; 161 for(csum = 0; ui >= ((__be32 *) vh);) { 162 cs = *ui--; 163 csum += be32_to_cpu(cs); 164 } 165 if (csum) { 166 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 167 return 0; 168 } 169 170 #ifdef DEBUG 171 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 172 173 for(i = 0; i < NVDIR; i++) { 174 int j; 175 char name[VDNAMESIZE+1]; 176 177 for(j = 0; j < VDNAMESIZE; j++) { 178 name[j] = vh->vh_vd[i].vd_name[j]; 179 } 180 name[j] = (char) 0; 181 182 if (name[0]) { 183 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 184 name, 185 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 186 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 187 } 188 } 189 #endif 190 191 for(i = 0; i < NPARTAB; i++) { 192 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 193 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 194 if (pt_type == pt_entry->pt_type) break; 195 } 196 #ifdef DEBUG 197 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 198 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 199 i, 200 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 201 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 202 pt_type, 203 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 204 } 205 #endif 206 if (IS_EFS(pt_type)) { 207 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 208 slice = i; 209 } 210 } 211 212 if (slice == -1) { 213 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 214 #ifdef DEBUG 215 } else { 216 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 217 slice, 218 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 219 sblock); 220 #endif 221 } 222 return sblock; 223 } 224 225 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 226 227 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 228 return -1; 229 230 sb->fs_magic = be32_to_cpu(super->fs_magic); 231 sb->total_blocks = be32_to_cpu(super->fs_size); 232 sb->first_block = be32_to_cpu(super->fs_firstcg); 233 sb->group_size = be32_to_cpu(super->fs_cgfsize); 234 sb->data_free = be32_to_cpu(super->fs_tfree); 235 sb->inode_free = be32_to_cpu(super->fs_tinode); 236 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 237 sb->total_groups = be16_to_cpu(super->fs_ncg); 238 239 return 0; 240 } 241 242 static int efs_fill_super(struct super_block *s, void *d, int silent) 243 { 244 struct efs_sb_info *sb; 245 struct buffer_head *bh; 246 struct inode *root; 247 248 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 249 if (!sb) 250 return -ENOMEM; 251 s->s_fs_info = sb; 252 253 s->s_magic = EFS_SUPER_MAGIC; 254 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 255 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 256 EFS_BLOCKSIZE); 257 goto out_no_fs_ul; 258 } 259 260 /* read the vh (volume header) block */ 261 bh = sb_bread(s, 0); 262 263 if (!bh) { 264 printk(KERN_ERR "EFS: cannot read volume header\n"); 265 goto out_no_fs_ul; 266 } 267 268 /* 269 * if this returns zero then we didn't find any partition table. 270 * this isn't (yet) an error - just assume for the moment that 271 * the device is valid and go on to search for a superblock. 272 */ 273 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 274 brelse(bh); 275 276 if (sb->fs_start == -1) { 277 goto out_no_fs_ul; 278 } 279 280 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 281 if (!bh) { 282 printk(KERN_ERR "EFS: cannot read superblock\n"); 283 goto out_no_fs_ul; 284 } 285 286 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 287 #ifdef DEBUG 288 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 289 #endif 290 brelse(bh); 291 goto out_no_fs_ul; 292 } 293 brelse(bh); 294 295 if (!(s->s_flags & MS_RDONLY)) { 296 #ifdef DEBUG 297 printk(KERN_INFO "EFS: forcing read-only mode\n"); 298 #endif 299 s->s_flags |= MS_RDONLY; 300 } 301 s->s_op = &efs_superblock_operations; 302 s->s_export_op = &efs_export_ops; 303 root = iget(s, EFS_ROOTINODE); 304 s->s_root = d_alloc_root(root); 305 306 if (!(s->s_root)) { 307 printk(KERN_ERR "EFS: get root inode failed\n"); 308 iput(root); 309 goto out_no_fs; 310 } 311 312 return 0; 313 314 out_no_fs_ul: 315 out_no_fs: 316 s->s_fs_info = NULL; 317 kfree(sb); 318 return -EINVAL; 319 } 320 321 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 322 struct efs_sb_info *sb = SUPER_INFO(dentry->d_sb); 323 324 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 325 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 326 buf->f_blocks = sb->total_groups * /* total data blocks */ 327 (sb->group_size - sb->inode_blocks); 328 buf->f_bfree = sb->data_free; /* free data blocks */ 329 buf->f_bavail = sb->data_free; /* free blocks for non-root */ 330 buf->f_files = sb->total_groups * /* total inodes */ 331 sb->inode_blocks * 332 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 333 buf->f_ffree = sb->inode_free; /* free inodes */ 334 buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */ 335 buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */ 336 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 337 338 return 0; 339 } 340 341