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 kmem_cache_destroy(efs_inode_cachep); 100 } 101 102 static void efs_put_super(struct super_block *s) 103 { 104 kfree(s->s_fs_info); 105 s->s_fs_info = NULL; 106 } 107 108 static int efs_remount(struct super_block *sb, int *flags, char *data) 109 { 110 *flags |= MS_RDONLY; 111 return 0; 112 } 113 114 static const struct super_operations efs_superblock_operations = { 115 .alloc_inode = efs_alloc_inode, 116 .destroy_inode = efs_destroy_inode, 117 .put_super = efs_put_super, 118 .statfs = efs_statfs, 119 .remount_fs = efs_remount, 120 }; 121 122 static const struct export_operations efs_export_ops = { 123 .fh_to_dentry = efs_fh_to_dentry, 124 .fh_to_parent = efs_fh_to_parent, 125 .get_parent = efs_get_parent, 126 }; 127 128 static int __init init_efs_fs(void) { 129 int err; 130 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 131 err = init_inodecache(); 132 if (err) 133 goto out1; 134 err = register_filesystem(&efs_fs_type); 135 if (err) 136 goto out; 137 return 0; 138 out: 139 destroy_inodecache(); 140 out1: 141 return err; 142 } 143 144 static void __exit exit_efs_fs(void) { 145 unregister_filesystem(&efs_fs_type); 146 destroy_inodecache(); 147 } 148 149 module_init(init_efs_fs) 150 module_exit(exit_efs_fs) 151 152 static efs_block_t efs_validate_vh(struct volume_header *vh) { 153 int i; 154 __be32 cs, *ui; 155 int csum; 156 efs_block_t sblock = 0; /* shuts up gcc */ 157 struct pt_types *pt_entry; 158 int pt_type, slice = -1; 159 160 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 161 /* 162 * assume that we're dealing with a partition and allow 163 * read_super() to try and detect a valid superblock 164 * on the next block. 165 */ 166 return 0; 167 } 168 169 ui = ((__be32 *) (vh + 1)) - 1; 170 for(csum = 0; ui >= ((__be32 *) vh);) { 171 cs = *ui--; 172 csum += be32_to_cpu(cs); 173 } 174 if (csum) { 175 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 176 return 0; 177 } 178 179 #ifdef DEBUG 180 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 181 182 for(i = 0; i < NVDIR; i++) { 183 int j; 184 char name[VDNAMESIZE+1]; 185 186 for(j = 0; j < VDNAMESIZE; j++) { 187 name[j] = vh->vh_vd[i].vd_name[j]; 188 } 189 name[j] = (char) 0; 190 191 if (name[0]) { 192 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 193 name, 194 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 195 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 196 } 197 } 198 #endif 199 200 for(i = 0; i < NPARTAB; i++) { 201 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 202 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 203 if (pt_type == pt_entry->pt_type) break; 204 } 205 #ifdef DEBUG 206 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 207 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 208 i, 209 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 210 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 211 pt_type, 212 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 213 } 214 #endif 215 if (IS_EFS(pt_type)) { 216 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 217 slice = i; 218 } 219 } 220 221 if (slice == -1) { 222 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 223 #ifdef DEBUG 224 } else { 225 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 226 slice, 227 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 228 sblock); 229 #endif 230 } 231 return sblock; 232 } 233 234 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 235 236 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 237 return -1; 238 239 sb->fs_magic = be32_to_cpu(super->fs_magic); 240 sb->total_blocks = be32_to_cpu(super->fs_size); 241 sb->first_block = be32_to_cpu(super->fs_firstcg); 242 sb->group_size = be32_to_cpu(super->fs_cgfsize); 243 sb->data_free = be32_to_cpu(super->fs_tfree); 244 sb->inode_free = be32_to_cpu(super->fs_tinode); 245 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 246 sb->total_groups = be16_to_cpu(super->fs_ncg); 247 248 return 0; 249 } 250 251 static int efs_fill_super(struct super_block *s, void *d, int silent) 252 { 253 struct efs_sb_info *sb; 254 struct buffer_head *bh; 255 struct inode *root; 256 int ret = -EINVAL; 257 258 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 259 if (!sb) 260 return -ENOMEM; 261 s->s_fs_info = sb; 262 263 s->s_magic = EFS_SUPER_MAGIC; 264 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 265 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 266 EFS_BLOCKSIZE); 267 goto out_no_fs_ul; 268 } 269 270 /* read the vh (volume header) block */ 271 bh = sb_bread(s, 0); 272 273 if (!bh) { 274 printk(KERN_ERR "EFS: cannot read volume header\n"); 275 goto out_no_fs_ul; 276 } 277 278 /* 279 * if this returns zero then we didn't find any partition table. 280 * this isn't (yet) an error - just assume for the moment that 281 * the device is valid and go on to search for a superblock. 282 */ 283 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 284 brelse(bh); 285 286 if (sb->fs_start == -1) { 287 goto out_no_fs_ul; 288 } 289 290 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 291 if (!bh) { 292 printk(KERN_ERR "EFS: cannot read superblock\n"); 293 goto out_no_fs_ul; 294 } 295 296 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 297 #ifdef DEBUG 298 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 299 #endif 300 brelse(bh); 301 goto out_no_fs_ul; 302 } 303 brelse(bh); 304 305 if (!(s->s_flags & MS_RDONLY)) { 306 #ifdef DEBUG 307 printk(KERN_INFO "EFS: forcing read-only mode\n"); 308 #endif 309 s->s_flags |= MS_RDONLY; 310 } 311 s->s_op = &efs_superblock_operations; 312 s->s_export_op = &efs_export_ops; 313 root = efs_iget(s, EFS_ROOTINODE); 314 if (IS_ERR(root)) { 315 printk(KERN_ERR "EFS: get root inode failed\n"); 316 ret = PTR_ERR(root); 317 goto out_no_fs; 318 } 319 320 s->s_root = d_alloc_root(root); 321 if (!(s->s_root)) { 322 printk(KERN_ERR "EFS: get root dentry failed\n"); 323 iput(root); 324 ret = -ENOMEM; 325 goto out_no_fs; 326 } 327 328 return 0; 329 330 out_no_fs_ul: 331 out_no_fs: 332 s->s_fs_info = NULL; 333 kfree(sb); 334 return ret; 335 } 336 337 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 338 struct super_block *sb = dentry->d_sb; 339 struct efs_sb_info *sbi = SUPER_INFO(sb); 340 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 341 342 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 343 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 344 buf->f_blocks = sbi->total_groups * /* total data blocks */ 345 (sbi->group_size - sbi->inode_blocks); 346 buf->f_bfree = sbi->data_free; /* free data blocks */ 347 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 348 buf->f_files = sbi->total_groups * /* total inodes */ 349 sbi->inode_blocks * 350 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 351 buf->f_ffree = sbi->inode_free; /* free inodes */ 352 buf->f_fsid.val[0] = (u32)id; 353 buf->f_fsid.val[1] = (u32)(id >> 32); 354 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 355 356 return 0; 357 } 358 359