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