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/exportfs.h> 12 #include <linux/slab.h> 13 #include <linux/buffer_head.h> 14 #include <linux/vfs.h> 15 16 #include "efs.h" 17 #include <linux/efs_vh.h> 18 #include <linux/efs_fs_sb.h> 19 20 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); 21 static int efs_fill_super(struct super_block *s, void *d, int silent); 22 23 static struct dentry *efs_mount(struct file_system_type *fs_type, 24 int flags, const char *dev_name, void *data) 25 { 26 return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super); 27 } 28 29 static void efs_kill_sb(struct super_block *s) 30 { 31 struct efs_sb_info *sbi = SUPER_INFO(s); 32 kill_block_super(s); 33 kfree(sbi); 34 } 35 36 static struct file_system_type efs_fs_type = { 37 .owner = THIS_MODULE, 38 .name = "efs", 39 .mount = efs_mount, 40 .kill_sb = efs_kill_sb, 41 .fs_flags = FS_REQUIRES_DEV, 42 }; 43 MODULE_ALIAS_FS("efs"); 44 45 static struct pt_types sgi_pt_types[] = { 46 {0x00, "SGI vh"}, 47 {0x01, "SGI trkrepl"}, 48 {0x02, "SGI secrepl"}, 49 {0x03, "SGI raw"}, 50 {0x04, "SGI bsd"}, 51 {SGI_SYSV, "SGI sysv"}, 52 {0x06, "SGI vol"}, 53 {SGI_EFS, "SGI efs"}, 54 {0x08, "SGI lv"}, 55 {0x09, "SGI rlv"}, 56 {0x0A, "SGI xfs"}, 57 {0x0B, "SGI xfslog"}, 58 {0x0C, "SGI xlv"}, 59 {0x82, "Linux swap"}, 60 {0x83, "Linux native"}, 61 {0, NULL} 62 }; 63 64 65 static struct kmem_cache * efs_inode_cachep; 66 67 static struct inode *efs_alloc_inode(struct super_block *sb) 68 { 69 struct efs_inode_info *ei; 70 ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 71 if (!ei) 72 return NULL; 73 return &ei->vfs_inode; 74 } 75 76 static void efs_i_callback(struct rcu_head *head) 77 { 78 struct inode *inode = container_of(head, struct inode, i_rcu); 79 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 80 } 81 82 static void efs_destroy_inode(struct inode *inode) 83 { 84 call_rcu(&inode->i_rcu, efs_i_callback); 85 } 86 87 static void init_once(void *foo) 88 { 89 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 90 91 inode_init_once(&ei->vfs_inode); 92 } 93 94 static int __init init_inodecache(void) 95 { 96 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 97 sizeof(struct efs_inode_info), 0, 98 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| 99 SLAB_ACCOUNT, init_once); 100 if (efs_inode_cachep == NULL) 101 return -ENOMEM; 102 return 0; 103 } 104 105 static void destroy_inodecache(void) 106 { 107 /* 108 * Make sure all delayed rcu free inodes are flushed before we 109 * destroy cache. 110 */ 111 rcu_barrier(); 112 kmem_cache_destroy(efs_inode_cachep); 113 } 114 115 static int efs_remount(struct super_block *sb, int *flags, char *data) 116 { 117 sync_filesystem(sb); 118 *flags |= MS_RDONLY; 119 return 0; 120 } 121 122 static const struct super_operations efs_superblock_operations = { 123 .alloc_inode = efs_alloc_inode, 124 .destroy_inode = efs_destroy_inode, 125 .statfs = efs_statfs, 126 .remount_fs = efs_remount, 127 }; 128 129 static const struct export_operations efs_export_ops = { 130 .fh_to_dentry = efs_fh_to_dentry, 131 .fh_to_parent = efs_fh_to_parent, 132 .get_parent = efs_get_parent, 133 }; 134 135 static int __init init_efs_fs(void) { 136 int err; 137 pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 138 err = init_inodecache(); 139 if (err) 140 goto out1; 141 err = register_filesystem(&efs_fs_type); 142 if (err) 143 goto out; 144 return 0; 145 out: 146 destroy_inodecache(); 147 out1: 148 return err; 149 } 150 151 static void __exit exit_efs_fs(void) { 152 unregister_filesystem(&efs_fs_type); 153 destroy_inodecache(); 154 } 155 156 module_init(init_efs_fs) 157 module_exit(exit_efs_fs) 158 159 static efs_block_t efs_validate_vh(struct volume_header *vh) { 160 int i; 161 __be32 cs, *ui; 162 int csum; 163 efs_block_t sblock = 0; /* shuts up gcc */ 164 struct pt_types *pt_entry; 165 int pt_type, slice = -1; 166 167 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 168 /* 169 * assume that we're dealing with a partition and allow 170 * read_super() to try and detect a valid superblock 171 * on the next block. 172 */ 173 return 0; 174 } 175 176 ui = ((__be32 *) (vh + 1)) - 1; 177 for(csum = 0; ui >= ((__be32 *) vh);) { 178 cs = *ui--; 179 csum += be32_to_cpu(cs); 180 } 181 if (csum) { 182 pr_warn("SGI disklabel: checksum bad, label corrupted\n"); 183 return 0; 184 } 185 186 #ifdef DEBUG 187 pr_debug("bf: \"%16s\"\n", vh->vh_bootfile); 188 189 for(i = 0; i < NVDIR; i++) { 190 int j; 191 char name[VDNAMESIZE+1]; 192 193 for(j = 0; j < VDNAMESIZE; j++) { 194 name[j] = vh->vh_vd[i].vd_name[j]; 195 } 196 name[j] = (char) 0; 197 198 if (name[0]) { 199 pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n", 200 name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 201 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 202 } 203 } 204 #endif 205 206 for(i = 0; i < NPARTAB; i++) { 207 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 208 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 209 if (pt_type == pt_entry->pt_type) break; 210 } 211 #ifdef DEBUG 212 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 213 pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 214 i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 215 (int)be32_to_cpu(vh->vh_pt[i].pt_nblks), 216 pt_type, (pt_entry->pt_name) ? 217 pt_entry->pt_name : "unknown"); 218 } 219 #endif 220 if (IS_EFS(pt_type)) { 221 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 222 slice = i; 223 } 224 } 225 226 if (slice == -1) { 227 pr_notice("partition table contained no EFS partitions\n"); 228 #ifdef DEBUG 229 } else { 230 pr_info("using slice %d (type %s, offset 0x%x)\n", slice, 231 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 232 sblock); 233 #endif 234 } 235 return sblock; 236 } 237 238 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 239 240 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 241 return -1; 242 243 sb->fs_magic = be32_to_cpu(super->fs_magic); 244 sb->total_blocks = be32_to_cpu(super->fs_size); 245 sb->first_block = be32_to_cpu(super->fs_firstcg); 246 sb->group_size = be32_to_cpu(super->fs_cgfsize); 247 sb->data_free = be32_to_cpu(super->fs_tfree); 248 sb->inode_free = be32_to_cpu(super->fs_tinode); 249 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 250 sb->total_groups = be16_to_cpu(super->fs_ncg); 251 252 return 0; 253 } 254 255 static int efs_fill_super(struct super_block *s, void *d, int silent) 256 { 257 struct efs_sb_info *sb; 258 struct buffer_head *bh; 259 struct inode *root; 260 261 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 262 if (!sb) 263 return -ENOMEM; 264 s->s_fs_info = sb; 265 266 s->s_magic = EFS_SUPER_MAGIC; 267 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 268 pr_err("device does not support %d byte blocks\n", 269 EFS_BLOCKSIZE); 270 return -EINVAL; 271 } 272 273 /* read the vh (volume header) block */ 274 bh = sb_bread(s, 0); 275 276 if (!bh) { 277 pr_err("cannot read volume header\n"); 278 return -EINVAL; 279 } 280 281 /* 282 * if this returns zero then we didn't find any partition table. 283 * this isn't (yet) an error - just assume for the moment that 284 * the device is valid and go on to search for a superblock. 285 */ 286 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 287 brelse(bh); 288 289 if (sb->fs_start == -1) { 290 return -EINVAL; 291 } 292 293 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 294 if (!bh) { 295 pr_err("cannot read superblock\n"); 296 return -EINVAL; 297 } 298 299 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 300 #ifdef DEBUG 301 pr_warn("invalid superblock at block %u\n", 302 sb->fs_start + EFS_SUPER); 303 #endif 304 brelse(bh); 305 return -EINVAL; 306 } 307 brelse(bh); 308 309 if (!(s->s_flags & MS_RDONLY)) { 310 #ifdef DEBUG 311 pr_info("forcing read-only mode\n"); 312 #endif 313 s->s_flags |= MS_RDONLY; 314 } 315 s->s_op = &efs_superblock_operations; 316 s->s_export_op = &efs_export_ops; 317 root = efs_iget(s, EFS_ROOTINODE); 318 if (IS_ERR(root)) { 319 pr_err("get root inode failed\n"); 320 return PTR_ERR(root); 321 } 322 323 s->s_root = d_make_root(root); 324 if (!(s->s_root)) { 325 pr_err("get root dentry failed\n"); 326 return -ENOMEM; 327 } 328 329 return 0; 330 } 331 332 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 333 struct super_block *sb = dentry->d_sb; 334 struct efs_sb_info *sbi = SUPER_INFO(sb); 335 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 336 337 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 338 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 339 buf->f_blocks = sbi->total_groups * /* total data blocks */ 340 (sbi->group_size - sbi->inode_blocks); 341 buf->f_bfree = sbi->data_free; /* free data blocks */ 342 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 343 buf->f_files = sbi->total_groups * /* total inodes */ 344 sbi->inode_blocks * 345 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 346 buf->f_ffree = sbi->inode_free; /* free inodes */ 347 buf->f_fsid.val[0] = (u32)id; 348 buf->f_fsid.val[1] = (u32)(id >> 32); 349 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 350 351 return 0; 352 } 353 354