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 = (struct efs_inode_info *)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_inodecache(void) 95 { 96 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 97 sizeof(struct efs_inode_info), 98 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 99 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 *flags |= MS_RDONLY; 118 return 0; 119 } 120 121 static const struct super_operations efs_superblock_operations = { 122 .alloc_inode = efs_alloc_inode, 123 .destroy_inode = efs_destroy_inode, 124 .statfs = efs_statfs, 125 .remount_fs = efs_remount, 126 }; 127 128 static const struct export_operations efs_export_ops = { 129 .fh_to_dentry = efs_fh_to_dentry, 130 .fh_to_parent = efs_fh_to_parent, 131 .get_parent = efs_get_parent, 132 }; 133 134 static int __init init_efs_fs(void) { 135 int err; 136 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 137 err = init_inodecache(); 138 if (err) 139 goto out1; 140 err = register_filesystem(&efs_fs_type); 141 if (err) 142 goto out; 143 return 0; 144 out: 145 destroy_inodecache(); 146 out1: 147 return err; 148 } 149 150 static void __exit exit_efs_fs(void) { 151 unregister_filesystem(&efs_fs_type); 152 destroy_inodecache(); 153 } 154 155 module_init(init_efs_fs) 156 module_exit(exit_efs_fs) 157 158 static efs_block_t efs_validate_vh(struct volume_header *vh) { 159 int i; 160 __be32 cs, *ui; 161 int csum; 162 efs_block_t sblock = 0; /* shuts up gcc */ 163 struct pt_types *pt_entry; 164 int pt_type, slice = -1; 165 166 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 167 /* 168 * assume that we're dealing with a partition and allow 169 * read_super() to try and detect a valid superblock 170 * on the next block. 171 */ 172 return 0; 173 } 174 175 ui = ((__be32 *) (vh + 1)) - 1; 176 for(csum = 0; ui >= ((__be32 *) vh);) { 177 cs = *ui--; 178 csum += be32_to_cpu(cs); 179 } 180 if (csum) { 181 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 182 return 0; 183 } 184 185 #ifdef DEBUG 186 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 187 188 for(i = 0; i < NVDIR; i++) { 189 int j; 190 char name[VDNAMESIZE+1]; 191 192 for(j = 0; j < VDNAMESIZE; j++) { 193 name[j] = vh->vh_vd[i].vd_name[j]; 194 } 195 name[j] = (char) 0; 196 197 if (name[0]) { 198 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 199 name, 200 (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 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 214 i, 215 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 216 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 217 pt_type, 218 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 219 } 220 #endif 221 if (IS_EFS(pt_type)) { 222 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 223 slice = i; 224 } 225 } 226 227 if (slice == -1) { 228 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 229 #ifdef DEBUG 230 } else { 231 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 232 slice, 233 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 234 sblock); 235 #endif 236 } 237 return sblock; 238 } 239 240 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 241 242 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 243 return -1; 244 245 sb->fs_magic = be32_to_cpu(super->fs_magic); 246 sb->total_blocks = be32_to_cpu(super->fs_size); 247 sb->first_block = be32_to_cpu(super->fs_firstcg); 248 sb->group_size = be32_to_cpu(super->fs_cgfsize); 249 sb->data_free = be32_to_cpu(super->fs_tfree); 250 sb->inode_free = be32_to_cpu(super->fs_tinode); 251 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 252 sb->total_groups = be16_to_cpu(super->fs_ncg); 253 254 return 0; 255 } 256 257 static int efs_fill_super(struct super_block *s, void *d, int silent) 258 { 259 struct efs_sb_info *sb; 260 struct buffer_head *bh; 261 struct inode *root; 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 return -EINVAL; 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 return -EINVAL; 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 return -EINVAL; 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 return -EINVAL; 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 return -EINVAL; 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 return PTR_ERR(root); 322 } 323 324 s->s_root = d_make_root(root); 325 if (!(s->s_root)) { 326 printk(KERN_ERR "EFS: get root dentry failed\n"); 327 return -ENOMEM; 328 } 329 330 return 0; 331 } 332 333 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 334 struct super_block *sb = dentry->d_sb; 335 struct efs_sb_info *sbi = SUPER_INFO(sb); 336 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 337 338 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 339 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 340 buf->f_blocks = sbi->total_groups * /* total data blocks */ 341 (sbi->group_size - sbi->inode_blocks); 342 buf->f_bfree = sbi->data_free; /* free data blocks */ 343 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 344 buf->f_files = sbi->total_groups * /* total inodes */ 345 sbi->inode_blocks * 346 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 347 buf->f_ffree = sbi->inode_free; /* free inodes */ 348 buf->f_fsid.val[0] = (u32)id; 349 buf->f_fsid.val[1] = (u32)(id >> 32); 350 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 351 352 return 0; 353 } 354 355