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/exportfs.h> 15 #include <linux/slab.h> 16 #include <linux/buffer_head.h> 17 #include <linux/vfs.h> 18 19 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); 20 static int efs_fill_super(struct super_block *s, void *d, int silent); 21 22 static int efs_get_sb(struct file_system_type *fs_type, 23 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 24 { 25 return get_sb_bdev(fs_type, flags, dev_name, data, efs_fill_super, mnt); 26 } 27 28 static struct file_system_type efs_fs_type = { 29 .owner = THIS_MODULE, 30 .name = "efs", 31 .get_sb = efs_get_sb, 32 .kill_sb = kill_block_super, 33 .fs_flags = FS_REQUIRES_DEV, 34 }; 35 36 static struct pt_types sgi_pt_types[] = { 37 {0x00, "SGI vh"}, 38 {0x01, "SGI trkrepl"}, 39 {0x02, "SGI secrepl"}, 40 {0x03, "SGI raw"}, 41 {0x04, "SGI bsd"}, 42 {SGI_SYSV, "SGI sysv"}, 43 {0x06, "SGI vol"}, 44 {SGI_EFS, "SGI efs"}, 45 {0x08, "SGI lv"}, 46 {0x09, "SGI rlv"}, 47 {0x0A, "SGI xfs"}, 48 {0x0B, "SGI xfslog"}, 49 {0x0C, "SGI xlv"}, 50 {0x82, "Linux swap"}, 51 {0x83, "Linux native"}, 52 {0, NULL} 53 }; 54 55 56 static struct kmem_cache * efs_inode_cachep; 57 58 static struct inode *efs_alloc_inode(struct super_block *sb) 59 { 60 struct efs_inode_info *ei; 61 ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 62 if (!ei) 63 return NULL; 64 return &ei->vfs_inode; 65 } 66 67 static void efs_destroy_inode(struct inode *inode) 68 { 69 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 70 } 71 72 static void init_once(struct kmem_cache *cachep, void *foo) 73 { 74 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 75 76 inode_init_once(&ei->vfs_inode); 77 } 78 79 static int init_inodecache(void) 80 { 81 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 82 sizeof(struct efs_inode_info), 83 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 84 init_once); 85 if (efs_inode_cachep == NULL) 86 return -ENOMEM; 87 return 0; 88 } 89 90 static void destroy_inodecache(void) 91 { 92 kmem_cache_destroy(efs_inode_cachep); 93 } 94 95 static void efs_put_super(struct super_block *s) 96 { 97 kfree(s->s_fs_info); 98 s->s_fs_info = NULL; 99 } 100 101 static int efs_remount(struct super_block *sb, int *flags, char *data) 102 { 103 *flags |= MS_RDONLY; 104 return 0; 105 } 106 107 static const struct super_operations efs_superblock_operations = { 108 .alloc_inode = efs_alloc_inode, 109 .destroy_inode = efs_destroy_inode, 110 .put_super = efs_put_super, 111 .statfs = efs_statfs, 112 .remount_fs = efs_remount, 113 }; 114 115 static const struct export_operations efs_export_ops = { 116 .fh_to_dentry = efs_fh_to_dentry, 117 .fh_to_parent = efs_fh_to_parent, 118 .get_parent = efs_get_parent, 119 }; 120 121 static int __init init_efs_fs(void) { 122 int err; 123 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 124 err = init_inodecache(); 125 if (err) 126 goto out1; 127 err = register_filesystem(&efs_fs_type); 128 if (err) 129 goto out; 130 return 0; 131 out: 132 destroy_inodecache(); 133 out1: 134 return err; 135 } 136 137 static void __exit exit_efs_fs(void) { 138 unregister_filesystem(&efs_fs_type); 139 destroy_inodecache(); 140 } 141 142 module_init(init_efs_fs) 143 module_exit(exit_efs_fs) 144 145 static efs_block_t efs_validate_vh(struct volume_header *vh) { 146 int i; 147 __be32 cs, *ui; 148 int csum; 149 efs_block_t sblock = 0; /* shuts up gcc */ 150 struct pt_types *pt_entry; 151 int pt_type, slice = -1; 152 153 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 154 /* 155 * assume that we're dealing with a partition and allow 156 * read_super() to try and detect a valid superblock 157 * on the next block. 158 */ 159 return 0; 160 } 161 162 ui = ((__be32 *) (vh + 1)) - 1; 163 for(csum = 0; ui >= ((__be32 *) vh);) { 164 cs = *ui--; 165 csum += be32_to_cpu(cs); 166 } 167 if (csum) { 168 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 169 return 0; 170 } 171 172 #ifdef DEBUG 173 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 174 175 for(i = 0; i < NVDIR; i++) { 176 int j; 177 char name[VDNAMESIZE+1]; 178 179 for(j = 0; j < VDNAMESIZE; j++) { 180 name[j] = vh->vh_vd[i].vd_name[j]; 181 } 182 name[j] = (char) 0; 183 184 if (name[0]) { 185 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 186 name, 187 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 188 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 189 } 190 } 191 #endif 192 193 for(i = 0; i < NPARTAB; i++) { 194 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 195 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 196 if (pt_type == pt_entry->pt_type) break; 197 } 198 #ifdef DEBUG 199 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 200 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 201 i, 202 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 203 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 204 pt_type, 205 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 206 } 207 #endif 208 if (IS_EFS(pt_type)) { 209 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 210 slice = i; 211 } 212 } 213 214 if (slice == -1) { 215 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 216 #ifdef DEBUG 217 } else { 218 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 219 slice, 220 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 221 sblock); 222 #endif 223 } 224 return sblock; 225 } 226 227 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 228 229 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 230 return -1; 231 232 sb->fs_magic = be32_to_cpu(super->fs_magic); 233 sb->total_blocks = be32_to_cpu(super->fs_size); 234 sb->first_block = be32_to_cpu(super->fs_firstcg); 235 sb->group_size = be32_to_cpu(super->fs_cgfsize); 236 sb->data_free = be32_to_cpu(super->fs_tfree); 237 sb->inode_free = be32_to_cpu(super->fs_tinode); 238 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 239 sb->total_groups = be16_to_cpu(super->fs_ncg); 240 241 return 0; 242 } 243 244 static int efs_fill_super(struct super_block *s, void *d, int silent) 245 { 246 struct efs_sb_info *sb; 247 struct buffer_head *bh; 248 struct inode *root; 249 int ret = -EINVAL; 250 251 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 252 if (!sb) 253 return -ENOMEM; 254 s->s_fs_info = sb; 255 256 s->s_magic = EFS_SUPER_MAGIC; 257 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 258 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 259 EFS_BLOCKSIZE); 260 goto out_no_fs_ul; 261 } 262 263 /* read the vh (volume header) block */ 264 bh = sb_bread(s, 0); 265 266 if (!bh) { 267 printk(KERN_ERR "EFS: cannot read volume header\n"); 268 goto out_no_fs_ul; 269 } 270 271 /* 272 * if this returns zero then we didn't find any partition table. 273 * this isn't (yet) an error - just assume for the moment that 274 * the device is valid and go on to search for a superblock. 275 */ 276 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 277 brelse(bh); 278 279 if (sb->fs_start == -1) { 280 goto out_no_fs_ul; 281 } 282 283 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 284 if (!bh) { 285 printk(KERN_ERR "EFS: cannot read superblock\n"); 286 goto out_no_fs_ul; 287 } 288 289 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 290 #ifdef DEBUG 291 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 292 #endif 293 brelse(bh); 294 goto out_no_fs_ul; 295 } 296 brelse(bh); 297 298 if (!(s->s_flags & MS_RDONLY)) { 299 #ifdef DEBUG 300 printk(KERN_INFO "EFS: forcing read-only mode\n"); 301 #endif 302 s->s_flags |= MS_RDONLY; 303 } 304 s->s_op = &efs_superblock_operations; 305 s->s_export_op = &efs_export_ops; 306 root = efs_iget(s, EFS_ROOTINODE); 307 if (IS_ERR(root)) { 308 printk(KERN_ERR "EFS: get root inode failed\n"); 309 ret = PTR_ERR(root); 310 goto out_no_fs; 311 } 312 313 s->s_root = d_alloc_root(root); 314 if (!(s->s_root)) { 315 printk(KERN_ERR "EFS: get root dentry failed\n"); 316 iput(root); 317 ret = -ENOMEM; 318 goto out_no_fs; 319 } 320 321 return 0; 322 323 out_no_fs_ul: 324 out_no_fs: 325 s->s_fs_info = NULL; 326 kfree(sb); 327 return ret; 328 } 329 330 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 331 struct efs_sb_info *sb = SUPER_INFO(dentry->d_sb); 332 333 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 334 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 335 buf->f_blocks = sb->total_groups * /* total data blocks */ 336 (sb->group_size - sb->inode_blocks); 337 buf->f_bfree = sb->data_free; /* free data blocks */ 338 buf->f_bavail = sb->data_free; /* free blocks for non-root */ 339 buf->f_files = sb->total_groups * /* total inodes */ 340 sb->inode_blocks * 341 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 342 buf->f_ffree = sb->inode_free; /* free inodes */ 343 buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */ 344 buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */ 345 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 346 347 return 0; 348 } 349 350