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 INIT_LIST_HEAD(&inode->i_dentry); 72 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 73 } 74 75 static void efs_destroy_inode(struct inode *inode) 76 { 77 call_rcu(&inode->i_rcu, efs_i_callback); 78 } 79 80 static void init_once(void *foo) 81 { 82 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 83 84 inode_init_once(&ei->vfs_inode); 85 } 86 87 static int init_inodecache(void) 88 { 89 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 90 sizeof(struct efs_inode_info), 91 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 92 init_once); 93 if (efs_inode_cachep == NULL) 94 return -ENOMEM; 95 return 0; 96 } 97 98 static void destroy_inodecache(void) 99 { 100 kmem_cache_destroy(efs_inode_cachep); 101 } 102 103 static void efs_put_super(struct super_block *s) 104 { 105 kfree(s->s_fs_info); 106 s->s_fs_info = NULL; 107 } 108 109 static int efs_remount(struct super_block *sb, int *flags, char *data) 110 { 111 *flags |= MS_RDONLY; 112 return 0; 113 } 114 115 static const struct super_operations efs_superblock_operations = { 116 .alloc_inode = efs_alloc_inode, 117 .destroy_inode = efs_destroy_inode, 118 .put_super = efs_put_super, 119 .statfs = efs_statfs, 120 .remount_fs = efs_remount, 121 }; 122 123 static const struct export_operations efs_export_ops = { 124 .fh_to_dentry = efs_fh_to_dentry, 125 .fh_to_parent = efs_fh_to_parent, 126 .get_parent = efs_get_parent, 127 }; 128 129 static int __init init_efs_fs(void) { 130 int err; 131 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 132 err = init_inodecache(); 133 if (err) 134 goto out1; 135 err = register_filesystem(&efs_fs_type); 136 if (err) 137 goto out; 138 return 0; 139 out: 140 destroy_inodecache(); 141 out1: 142 return err; 143 } 144 145 static void __exit exit_efs_fs(void) { 146 unregister_filesystem(&efs_fs_type); 147 destroy_inodecache(); 148 } 149 150 module_init(init_efs_fs) 151 module_exit(exit_efs_fs) 152 153 static efs_block_t efs_validate_vh(struct volume_header *vh) { 154 int i; 155 __be32 cs, *ui; 156 int csum; 157 efs_block_t sblock = 0; /* shuts up gcc */ 158 struct pt_types *pt_entry; 159 int pt_type, slice = -1; 160 161 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 162 /* 163 * assume that we're dealing with a partition and allow 164 * read_super() to try and detect a valid superblock 165 * on the next block. 166 */ 167 return 0; 168 } 169 170 ui = ((__be32 *) (vh + 1)) - 1; 171 for(csum = 0; ui >= ((__be32 *) vh);) { 172 cs = *ui--; 173 csum += be32_to_cpu(cs); 174 } 175 if (csum) { 176 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 177 return 0; 178 } 179 180 #ifdef DEBUG 181 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 182 183 for(i = 0; i < NVDIR; i++) { 184 int j; 185 char name[VDNAMESIZE+1]; 186 187 for(j = 0; j < VDNAMESIZE; j++) { 188 name[j] = vh->vh_vd[i].vd_name[j]; 189 } 190 name[j] = (char) 0; 191 192 if (name[0]) { 193 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 194 name, 195 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 196 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 197 } 198 } 199 #endif 200 201 for(i = 0; i < NPARTAB; i++) { 202 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 203 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 204 if (pt_type == pt_entry->pt_type) break; 205 } 206 #ifdef DEBUG 207 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 208 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 209 i, 210 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 211 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 212 pt_type, 213 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 214 } 215 #endif 216 if (IS_EFS(pt_type)) { 217 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 218 slice = i; 219 } 220 } 221 222 if (slice == -1) { 223 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 224 #ifdef DEBUG 225 } else { 226 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 227 slice, 228 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 229 sblock); 230 #endif 231 } 232 return sblock; 233 } 234 235 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 236 237 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 238 return -1; 239 240 sb->fs_magic = be32_to_cpu(super->fs_magic); 241 sb->total_blocks = be32_to_cpu(super->fs_size); 242 sb->first_block = be32_to_cpu(super->fs_firstcg); 243 sb->group_size = be32_to_cpu(super->fs_cgfsize); 244 sb->data_free = be32_to_cpu(super->fs_tfree); 245 sb->inode_free = be32_to_cpu(super->fs_tinode); 246 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 247 sb->total_groups = be16_to_cpu(super->fs_ncg); 248 249 return 0; 250 } 251 252 static int efs_fill_super(struct super_block *s, void *d, int silent) 253 { 254 struct efs_sb_info *sb; 255 struct buffer_head *bh; 256 struct inode *root; 257 int ret = -EINVAL; 258 259 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 260 if (!sb) 261 return -ENOMEM; 262 s->s_fs_info = sb; 263 264 s->s_magic = EFS_SUPER_MAGIC; 265 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 266 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 267 EFS_BLOCKSIZE); 268 goto out_no_fs_ul; 269 } 270 271 /* read the vh (volume header) block */ 272 bh = sb_bread(s, 0); 273 274 if (!bh) { 275 printk(KERN_ERR "EFS: cannot read volume header\n"); 276 goto out_no_fs_ul; 277 } 278 279 /* 280 * if this returns zero then we didn't find any partition table. 281 * this isn't (yet) an error - just assume for the moment that 282 * the device is valid and go on to search for a superblock. 283 */ 284 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 285 brelse(bh); 286 287 if (sb->fs_start == -1) { 288 goto out_no_fs_ul; 289 } 290 291 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 292 if (!bh) { 293 printk(KERN_ERR "EFS: cannot read superblock\n"); 294 goto out_no_fs_ul; 295 } 296 297 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 298 #ifdef DEBUG 299 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 300 #endif 301 brelse(bh); 302 goto out_no_fs_ul; 303 } 304 brelse(bh); 305 306 if (!(s->s_flags & MS_RDONLY)) { 307 #ifdef DEBUG 308 printk(KERN_INFO "EFS: forcing read-only mode\n"); 309 #endif 310 s->s_flags |= MS_RDONLY; 311 } 312 s->s_op = &efs_superblock_operations; 313 s->s_export_op = &efs_export_ops; 314 root = efs_iget(s, EFS_ROOTINODE); 315 if (IS_ERR(root)) { 316 printk(KERN_ERR "EFS: get root inode failed\n"); 317 ret = PTR_ERR(root); 318 goto out_no_fs; 319 } 320 321 s->s_root = d_alloc_root(root); 322 if (!(s->s_root)) { 323 printk(KERN_ERR "EFS: get root dentry failed\n"); 324 iput(root); 325 ret = -ENOMEM; 326 goto out_no_fs; 327 } 328 329 return 0; 330 331 out_no_fs_ul: 332 out_no_fs: 333 s->s_fs_info = NULL; 334 kfree(sb); 335 return ret; 336 } 337 338 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 339 struct super_block *sb = dentry->d_sb; 340 struct efs_sb_info *sbi = SUPER_INFO(sb); 341 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 342 343 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 344 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 345 buf->f_blocks = sbi->total_groups * /* total data blocks */ 346 (sbi->group_size - sbi->inode_blocks); 347 buf->f_bfree = sbi->data_free; /* free data blocks */ 348 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 349 buf->f_files = sbi->total_groups * /* total inodes */ 350 sbi->inode_blocks * 351 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 352 buf->f_ffree = sbi->inode_free; /* free inodes */ 353 buf->f_fsid.val[0] = (u32)id; 354 buf->f_fsid.val[1] = (u32)(id >> 32); 355 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 356 357 return 0; 358 } 359 360