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/efs_fs.h> 12 #include <linux/efs_vh.h> 13 #include <linux/efs_fs_sb.h> 14 #include <linux/slab.h> 15 #include <linux/buffer_head.h> 16 #include <linux/vfs.h> 17 18 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); 19 static int efs_fill_super(struct super_block *s, void *d, int silent); 20 21 static int efs_get_sb(struct file_system_type *fs_type, 22 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 23 { 24 return get_sb_bdev(fs_type, flags, dev_name, data, efs_fill_super, mnt); 25 } 26 27 static struct file_system_type efs_fs_type = { 28 .owner = THIS_MODULE, 29 .name = "efs", 30 .get_sb = efs_get_sb, 31 .kill_sb = kill_block_super, 32 .fs_flags = FS_REQUIRES_DEV, 33 }; 34 35 static struct pt_types sgi_pt_types[] = { 36 {0x00, "SGI vh"}, 37 {0x01, "SGI trkrepl"}, 38 {0x02, "SGI secrepl"}, 39 {0x03, "SGI raw"}, 40 {0x04, "SGI bsd"}, 41 {SGI_SYSV, "SGI sysv"}, 42 {0x06, "SGI vol"}, 43 {SGI_EFS, "SGI efs"}, 44 {0x08, "SGI lv"}, 45 {0x09, "SGI rlv"}, 46 {0x0A, "SGI xfs"}, 47 {0x0B, "SGI xfslog"}, 48 {0x0C, "SGI xlv"}, 49 {0x82, "Linux swap"}, 50 {0x83, "Linux native"}, 51 {0, NULL} 52 }; 53 54 55 static struct kmem_cache * efs_inode_cachep; 56 57 static struct inode *efs_alloc_inode(struct super_block *sb) 58 { 59 struct efs_inode_info *ei; 60 ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 61 if (!ei) 62 return NULL; 63 return &ei->vfs_inode; 64 } 65 66 static void efs_destroy_inode(struct inode *inode) 67 { 68 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 69 } 70 71 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 72 { 73 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 74 75 if (flags & SLAB_CTOR_CONSTRUCTOR) 76 inode_init_once(&ei->vfs_inode); 77 } 78 79 static int init_inodecache(void) 80 { 81 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 82 sizeof(struct efs_inode_info), 83 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, 84 init_once, NULL); 85 if (efs_inode_cachep == NULL) 86 return -ENOMEM; 87 return 0; 88 } 89 90 static void destroy_inodecache(void) 91 { 92 kmem_cache_destroy(efs_inode_cachep); 93 } 94 95 static void efs_put_super(struct super_block *s) 96 { 97 kfree(s->s_fs_info); 98 s->s_fs_info = NULL; 99 } 100 101 static int efs_remount(struct super_block *sb, int *flags, char *data) 102 { 103 *flags |= MS_RDONLY; 104 return 0; 105 } 106 107 static const struct super_operations efs_superblock_operations = { 108 .alloc_inode = efs_alloc_inode, 109 .destroy_inode = efs_destroy_inode, 110 .read_inode = efs_read_inode, 111 .put_super = efs_put_super, 112 .statfs = efs_statfs, 113 .remount_fs = efs_remount, 114 }; 115 116 static struct export_operations efs_export_ops = { 117 .get_parent = efs_get_parent, 118 }; 119 120 static int __init init_efs_fs(void) { 121 int err; 122 printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 123 err = init_inodecache(); 124 if (err) 125 goto out1; 126 err = register_filesystem(&efs_fs_type); 127 if (err) 128 goto out; 129 return 0; 130 out: 131 destroy_inodecache(); 132 out1: 133 return err; 134 } 135 136 static void __exit exit_efs_fs(void) { 137 unregister_filesystem(&efs_fs_type); 138 destroy_inodecache(); 139 } 140 141 module_init(init_efs_fs) 142 module_exit(exit_efs_fs) 143 144 static efs_block_t efs_validate_vh(struct volume_header *vh) { 145 int i; 146 __be32 cs, *ui; 147 int csum; 148 efs_block_t sblock = 0; /* shuts up gcc */ 149 struct pt_types *pt_entry; 150 int pt_type, slice = -1; 151 152 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 153 /* 154 * assume that we're dealing with a partition and allow 155 * read_super() to try and detect a valid superblock 156 * on the next block. 157 */ 158 return 0; 159 } 160 161 ui = ((__be32 *) (vh + 1)) - 1; 162 for(csum = 0; ui >= ((__be32 *) vh);) { 163 cs = *ui--; 164 csum += be32_to_cpu(cs); 165 } 166 if (csum) { 167 printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n"); 168 return 0; 169 } 170 171 #ifdef DEBUG 172 printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile); 173 174 for(i = 0; i < NVDIR; i++) { 175 int j; 176 char name[VDNAMESIZE+1]; 177 178 for(j = 0; j < VDNAMESIZE; j++) { 179 name[j] = vh->vh_vd[i].vd_name[j]; 180 } 181 name[j] = (char) 0; 182 183 if (name[0]) { 184 printk(KERN_DEBUG "EFS: vh: %8s block: 0x%08x size: 0x%08x\n", 185 name, 186 (int) be32_to_cpu(vh->vh_vd[i].vd_lbn), 187 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes)); 188 } 189 } 190 #endif 191 192 for(i = 0; i < NPARTAB; i++) { 193 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type); 194 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) { 195 if (pt_type == pt_entry->pt_type) break; 196 } 197 #ifdef DEBUG 198 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) { 199 printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 200 i, 201 (int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 202 (int) be32_to_cpu(vh->vh_pt[i].pt_nblks), 203 pt_type, 204 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown"); 205 } 206 #endif 207 if (IS_EFS(pt_type)) { 208 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn); 209 slice = i; 210 } 211 } 212 213 if (slice == -1) { 214 printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n"); 215 #ifdef DEBUG 216 } else { 217 printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n", 218 slice, 219 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 220 sblock); 221 #endif 222 } 223 return sblock; 224 } 225 226 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 227 228 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 229 return -1; 230 231 sb->fs_magic = be32_to_cpu(super->fs_magic); 232 sb->total_blocks = be32_to_cpu(super->fs_size); 233 sb->first_block = be32_to_cpu(super->fs_firstcg); 234 sb->group_size = be32_to_cpu(super->fs_cgfsize); 235 sb->data_free = be32_to_cpu(super->fs_tfree); 236 sb->inode_free = be32_to_cpu(super->fs_tinode); 237 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 238 sb->total_groups = be16_to_cpu(super->fs_ncg); 239 240 return 0; 241 } 242 243 static int efs_fill_super(struct super_block *s, void *d, int silent) 244 { 245 struct efs_sb_info *sb; 246 struct buffer_head *bh; 247 struct inode *root; 248 249 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 250 if (!sb) 251 return -ENOMEM; 252 s->s_fs_info = sb; 253 254 s->s_magic = EFS_SUPER_MAGIC; 255 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 256 printk(KERN_ERR "EFS: device does not support %d byte blocks\n", 257 EFS_BLOCKSIZE); 258 goto out_no_fs_ul; 259 } 260 261 /* read the vh (volume header) block */ 262 bh = sb_bread(s, 0); 263 264 if (!bh) { 265 printk(KERN_ERR "EFS: cannot read volume header\n"); 266 goto out_no_fs_ul; 267 } 268 269 /* 270 * if this returns zero then we didn't find any partition table. 271 * this isn't (yet) an error - just assume for the moment that 272 * the device is valid and go on to search for a superblock. 273 */ 274 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data); 275 brelse(bh); 276 277 if (sb->fs_start == -1) { 278 goto out_no_fs_ul; 279 } 280 281 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 282 if (!bh) { 283 printk(KERN_ERR "EFS: cannot read superblock\n"); 284 goto out_no_fs_ul; 285 } 286 287 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 288 #ifdef DEBUG 289 printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER); 290 #endif 291 brelse(bh); 292 goto out_no_fs_ul; 293 } 294 brelse(bh); 295 296 if (!(s->s_flags & MS_RDONLY)) { 297 #ifdef DEBUG 298 printk(KERN_INFO "EFS: forcing read-only mode\n"); 299 #endif 300 s->s_flags |= MS_RDONLY; 301 } 302 s->s_op = &efs_superblock_operations; 303 s->s_export_op = &efs_export_ops; 304 root = iget(s, EFS_ROOTINODE); 305 s->s_root = d_alloc_root(root); 306 307 if (!(s->s_root)) { 308 printk(KERN_ERR "EFS: get root inode failed\n"); 309 iput(root); 310 goto out_no_fs; 311 } 312 313 return 0; 314 315 out_no_fs_ul: 316 out_no_fs: 317 s->s_fs_info = NULL; 318 kfree(sb); 319 return -EINVAL; 320 } 321 322 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 323 struct efs_sb_info *sb = SUPER_INFO(dentry->d_sb); 324 325 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 326 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 327 buf->f_blocks = sb->total_groups * /* total data blocks */ 328 (sb->group_size - sb->inode_blocks); 329 buf->f_bfree = sb->data_free; /* free data blocks */ 330 buf->f_bavail = sb->data_free; /* free blocks for non-root */ 331 buf->f_files = sb->total_groups * /* total inodes */ 332 sb->inode_blocks * 333 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 334 buf->f_ffree = sb->inode_free; /* free inodes */ 335 buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */ 336 buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */ 337 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 338 339 return 0; 340 } 341 342