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 struct file_system_type efs_fs_type = { 30 .owner = THIS_MODULE, 31 .name = "efs", 32 .mount = efs_mount, 33 .kill_sb = kill_block_super, 34 .fs_flags = FS_REQUIRES_DEV, 35 }; 36 37 static struct pt_types sgi_pt_types[] = { 38 {0x00, "SGI vh"}, 39 {0x01, "SGI trkrepl"}, 40 {0x02, "SGI secrepl"}, 41 {0x03, "SGI raw"}, 42 {0x04, "SGI bsd"}, 43 {SGI_SYSV, "SGI sysv"}, 44 {0x06, "SGI vol"}, 45 {SGI_EFS, "SGI efs"}, 46 {0x08, "SGI lv"}, 47 {0x09, "SGI rlv"}, 48 {0x0A, "SGI xfs"}, 49 {0x0B, "SGI xfslog"}, 50 {0x0C, "SGI xlv"}, 51 {0x82, "Linux swap"}, 52 {0x83, "Linux native"}, 53 {0, NULL} 54 }; 55 56 57 static struct kmem_cache * efs_inode_cachep; 58 59 static struct inode *efs_alloc_inode(struct super_block *sb) 60 { 61 struct efs_inode_info *ei; 62 ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 63 if (!ei) 64 return NULL; 65 return &ei->vfs_inode; 66 } 67 68 static void efs_i_callback(struct rcu_head *head) 69 { 70 struct inode *inode = container_of(head, struct inode, i_rcu); 71 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 72 } 73 74 static void efs_destroy_inode(struct inode *inode) 75 { 76 call_rcu(&inode->i_rcu, efs_i_callback); 77 } 78 79 static void init_once(void *foo) 80 { 81 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 82 83 inode_init_once(&ei->vfs_inode); 84 } 85 86 static int init_inodecache(void) 87 { 88 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 89 sizeof(struct efs_inode_info), 90 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 91 init_once); 92 if (efs_inode_cachep == NULL) 93 return -ENOMEM; 94 return 0; 95 } 96 97 static void destroy_inodecache(void) 98 { 99 /* 100 * Make sure all delayed rcu free inodes are flushed before we 101 * destroy cache. 102 */ 103 rcu_barrier(); 104 kmem_cache_destroy(efs_inode_cachep); 105 } 106 107 static void efs_put_super(struct super_block *s) 108 { 109 kfree(s->s_fs_info); 110 s->s_fs_info = NULL; 111 } 112 113 static int efs_remount(struct super_block *sb, int *flags, char *data) 114 { 115 *flags |= MS_RDONLY; 116 return 0; 117 } 118 119 static const struct super_operations efs_superblock_operations = { 120 .alloc_inode = efs_alloc_inode, 121 .destroy_inode = efs_destroy_inode, 122 .put_super = efs_put_super, 123 .statfs = efs_statfs, 124 .remount_fs = efs_remount, 125 }; 126 127 static const struct export_operations efs_export_ops = { 128 .fh_to_dentry = efs_fh_to_dentry, 129 .fh_to_parent = efs_fh_to_parent, 130 .get_parent = efs_get_parent, 131 }; 132 133 static int __init init_efs_fs(void) { 134 int err; 135 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 136 err = init_inodecache(); 137 if (err) 138 goto out1; 139 err = register_filesystem(&efs_fs_type); 140 if (err) 141 goto out; 142 return 0; 143 out: 144 destroy_inodecache(); 145 out1: 146 return err; 147 } 148 149 static void __exit exit_efs_fs(void) { 150 unregister_filesystem(&efs_fs_type); 151 destroy_inodecache(); 152 } 153 154 module_init(init_efs_fs) 155 module_exit(exit_efs_fs) 156 157 static efs_block_t efs_validate_vh(struct volume_header *vh) { 158 int i; 159 __be32 cs, *ui; 160 int csum; 161 efs_block_t sblock = 0; /* shuts up gcc */ 162 struct pt_types *pt_entry; 163 int pt_type, slice = -1; 164 165 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 166 /* 167 * assume that we're dealing with a partition and allow 168 * read_super() to try and detect a valid superblock 169 * on the next block. 170 */ 171 return 0; 172 } 173 174 ui = ((__be32 *) (vh + 1)) - 1; 175 for(csum = 0; ui >= ((__be32 *) vh);) { 176 cs = *ui--; 177 csum += be32_to_cpu(cs); 178 } 179 if (csum) { 180 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 181 return 0; 182 } 183 184 #ifdef DEBUG 185 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 186 187 for(i = 0; i < NVDIR; i++) { 188 int j; 189 char name[VDNAMESIZE+1]; 190 191 for(j = 0; j < VDNAMESIZE; j++) { 192 name[j] = vh->vh_vd[i].vd_name[j]; 193 } 194 name[j] = (char) 0; 195 196 if (name[0]) { 197 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 198 name, 199 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 200 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 201 } 202 } 203 #endif 204 205 for(i = 0; i < NPARTAB; i++) { 206 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 207 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 208 if (pt_type == pt_entry->pt_type) break; 209 } 210 #ifdef DEBUG 211 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 212 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 213 i, 214 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 215 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 216 pt_type, 217 (pt_entry->pt_name) ? 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 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 228 #ifdef DEBUG 229 } else { 230 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 231 slice, 232 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 233 sblock); 234 #endif 235 } 236 return sblock; 237 } 238 239 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 240 241 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 242 return -1; 243 244 sb->fs_magic = be32_to_cpu(super->fs_magic); 245 sb->total_blocks = be32_to_cpu(super->fs_size); 246 sb->first_block = be32_to_cpu(super->fs_firstcg); 247 sb->group_size = be32_to_cpu(super->fs_cgfsize); 248 sb->data_free = be32_to_cpu(super->fs_tfree); 249 sb->inode_free = be32_to_cpu(super->fs_tinode); 250 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 251 sb->total_groups = be16_to_cpu(super->fs_ncg); 252 253 return 0; 254 } 255 256 static int efs_fill_super(struct super_block *s, void *d, int silent) 257 { 258 struct efs_sb_info *sb; 259 struct buffer_head *bh; 260 struct inode *root; 261 int ret = -EINVAL; 262 263 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 264 if (!sb) 265 return -ENOMEM; 266 s->s_fs_info = sb; 267 268 s->s_magic = EFS_SUPER_MAGIC; 269 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 270 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 271 EFS_BLOCKSIZE); 272 goto out_no_fs_ul; 273 } 274 275 /* read the vh (volume header) block */ 276 bh = sb_bread(s, 0); 277 278 if (!bh) { 279 printk(KERN_ERR "EFS: cannot read volume header\n"); 280 goto out_no_fs_ul; 281 } 282 283 /* 284 * if this returns zero then we didn't find any partition table. 285 * this isn't (yet) an error - just assume for the moment that 286 * the device is valid and go on to search for a superblock. 287 */ 288 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 289 brelse(bh); 290 291 if (sb->fs_start == -1) { 292 goto out_no_fs_ul; 293 } 294 295 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 296 if (!bh) { 297 printk(KERN_ERR "EFS: cannot read superblock\n"); 298 goto out_no_fs_ul; 299 } 300 301 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 302 #ifdef DEBUG 303 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 304 #endif 305 brelse(bh); 306 goto out_no_fs_ul; 307 } 308 brelse(bh); 309 310 if (!(s->s_flags & MS_RDONLY)) { 311 #ifdef DEBUG 312 printk(KERN_INFO "EFS: forcing read-only mode\n"); 313 #endif 314 s->s_flags |= MS_RDONLY; 315 } 316 s->s_op = &efs_superblock_operations; 317 s->s_export_op = &efs_export_ops; 318 root = efs_iget(s, EFS_ROOTINODE); 319 if (IS_ERR(root)) { 320 printk(KERN_ERR "EFS: get root inode failed\n"); 321 ret = PTR_ERR(root); 322 goto out_no_fs; 323 } 324 325 s->s_root = d_make_root(root); 326 if (!(s->s_root)) { 327 printk(KERN_ERR "EFS: get root dentry failed\n"); 328 ret = -ENOMEM; 329 goto out_no_fs; 330 } 331 332 return 0; 333 334 out_no_fs_ul: 335 out_no_fs: 336 s->s_fs_info = NULL; 337 kfree(sb); 338 return ret; 339 } 340 341 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 342 struct super_block *sb = dentry->d_sb; 343 struct efs_sb_info *sbi = SUPER_INFO(sb); 344 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 345 346 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 347 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 348 buf->f_blocks = sbi->total_groups * /* total data blocks */ 349 (sbi->group_size - sbi->inode_blocks); 350 buf->f_bfree = sbi->data_free; /* free data blocks */ 351 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 352 buf->f_files = sbi->total_groups * /* total inodes */ 353 sbi->inode_blocks * 354 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 355 buf->f_ffree = sbi->inode_free; /* free inodes */ 356 buf->f_fsid.val[0] = (u32)id; 357 buf->f_fsid.val[1] = (u32)(id >> 32); 358 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 359 360 return 0; 361 } 362 363