1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * super.c 4 * 5 * Copyright (c) 1999 Al Smith 6 * 7 * Portions derived from work (c) 1995,1996 Christian Vogelgsang. 8 */ 9 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/exportfs.h> 13 #include <linux/slab.h> 14 #include <linux/buffer_head.h> 15 #include <linux/vfs.h> 16 17 #include "efs.h" 18 #include <linux/efs_vh.h> 19 #include <linux/efs_fs_sb.h> 20 21 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf); 22 static int efs_fill_super(struct super_block *s, void *d, int silent); 23 24 static struct dentry *efs_mount(struct file_system_type *fs_type, 25 int flags, const char *dev_name, void *data) 26 { 27 return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super); 28 } 29 30 static void efs_kill_sb(struct super_block *s) 31 { 32 struct efs_sb_info *sbi = SUPER_INFO(s); 33 kill_block_super(s); 34 kfree(sbi); 35 } 36 37 static struct file_system_type efs_fs_type = { 38 .owner = THIS_MODULE, 39 .name = "efs", 40 .mount = efs_mount, 41 .kill_sb = efs_kill_sb, 42 .fs_flags = FS_REQUIRES_DEV, 43 }; 44 MODULE_ALIAS_FS("efs"); 45 46 static struct pt_types sgi_pt_types[] = { 47 {0x00, "SGI vh"}, 48 {0x01, "SGI trkrepl"}, 49 {0x02, "SGI secrepl"}, 50 {0x03, "SGI raw"}, 51 {0x04, "SGI bsd"}, 52 {SGI_SYSV, "SGI sysv"}, 53 {0x06, "SGI vol"}, 54 {SGI_EFS, "SGI efs"}, 55 {0x08, "SGI lv"}, 56 {0x09, "SGI rlv"}, 57 {0x0A, "SGI xfs"}, 58 {0x0B, "SGI xfslog"}, 59 {0x0C, "SGI xlv"}, 60 {0x82, "Linux swap"}, 61 {0x83, "Linux native"}, 62 {0, NULL} 63 }; 64 65 66 static struct kmem_cache * efs_inode_cachep; 67 68 static struct inode *efs_alloc_inode(struct super_block *sb) 69 { 70 struct efs_inode_info *ei; 71 ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); 72 if (!ei) 73 return NULL; 74 return &ei->vfs_inode; 75 } 76 77 static void efs_free_inode(struct inode *inode) 78 { 79 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode)); 80 } 81 82 static void init_once(void *foo) 83 { 84 struct efs_inode_info *ei = (struct efs_inode_info *) foo; 85 86 inode_init_once(&ei->vfs_inode); 87 } 88 89 static int __init init_inodecache(void) 90 { 91 efs_inode_cachep = kmem_cache_create("efs_inode_cache", 92 sizeof(struct efs_inode_info), 0, 93 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| 94 SLAB_ACCOUNT, init_once); 95 if (efs_inode_cachep == NULL) 96 return -ENOMEM; 97 return 0; 98 } 99 100 static void destroy_inodecache(void) 101 { 102 /* 103 * Make sure all delayed rcu free inodes are flushed before we 104 * destroy cache. 105 */ 106 rcu_barrier(); 107 kmem_cache_destroy(efs_inode_cachep); 108 } 109 110 static int efs_remount(struct super_block *sb, int *flags, char *data) 111 { 112 sync_filesystem(sb); 113 *flags |= SB_RDONLY; 114 return 0; 115 } 116 117 static const struct super_operations efs_superblock_operations = { 118 .alloc_inode = efs_alloc_inode, 119 .free_inode = efs_free_inode, 120 .statfs = efs_statfs, 121 .remount_fs = efs_remount, 122 }; 123 124 static const struct export_operations efs_export_ops = { 125 .fh_to_dentry = efs_fh_to_dentry, 126 .fh_to_parent = efs_fh_to_parent, 127 .get_parent = efs_get_parent, 128 }; 129 130 static int __init init_efs_fs(void) { 131 int err; 132 pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n"); 133 err = init_inodecache(); 134 if (err) 135 goto out1; 136 err = register_filesystem(&efs_fs_type); 137 if (err) 138 goto out; 139 return 0; 140 out: 141 destroy_inodecache(); 142 out1: 143 return err; 144 } 145 146 static void __exit exit_efs_fs(void) { 147 unregister_filesystem(&efs_fs_type); 148 destroy_inodecache(); 149 } 150 151 module_init(init_efs_fs) 152 module_exit(exit_efs_fs) 153 154 static efs_block_t efs_validate_vh(struct volume_header *vh) { 155 int i; 156 __be32 cs, *ui; 157 int csum; 158 efs_block_t sblock = 0; /* shuts up gcc */ 159 struct pt_types *pt_entry; 160 int pt_type, slice = -1; 161 162 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) { 163 /* 164 * assume that we're dealing with a partition and allow 165 * read_super() to try and detect a valid superblock 166 * on the next block. 167 */ 168 return 0; 169 } 170 171 ui = ((__be32 *) (vh + 1)) - 1; 172 for(csum = 0; ui >= ((__be32 *) vh);) { 173 cs = *ui--; 174 csum += be32_to_cpu(cs); 175 } 176 if (csum) { 177 pr_warn("SGI disklabel: checksum bad, label corrupted\n"); 178 return 0; 179 } 180 181 #ifdef DEBUG 182 pr_debug("bf: \"%16s\"\n", vh->vh_bootfile); 183 184 for(i = 0; i < NVDIR; i++) { 185 int j; 186 char name[VDNAMESIZE+1]; 187 188 for(j = 0; j < VDNAMESIZE; j++) { 189 name[j] = vh->vh_vd[i].vd_name[j]; 190 } 191 name[j] = (char) 0; 192 193 if (name[0]) { 194 pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n", 195 name, (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 pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n", 209 i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn), 210 (int)be32_to_cpu(vh->vh_pt[i].pt_nblks), 211 pt_type, (pt_entry->pt_name) ? 212 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 pr_notice("partition table contained no EFS partitions\n"); 223 #ifdef DEBUG 224 } else { 225 pr_info("using slice %d (type %s, offset 0x%x)\n", slice, 226 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown", 227 sblock); 228 #endif 229 } 230 return sblock; 231 } 232 233 static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) { 234 235 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) 236 return -1; 237 238 sb->fs_magic = be32_to_cpu(super->fs_magic); 239 sb->total_blocks = be32_to_cpu(super->fs_size); 240 sb->first_block = be32_to_cpu(super->fs_firstcg); 241 sb->group_size = be32_to_cpu(super->fs_cgfsize); 242 sb->data_free = be32_to_cpu(super->fs_tfree); 243 sb->inode_free = be32_to_cpu(super->fs_tinode); 244 sb->inode_blocks = be16_to_cpu(super->fs_cgisize); 245 sb->total_groups = be16_to_cpu(super->fs_ncg); 246 247 return 0; 248 } 249 250 static int efs_fill_super(struct super_block *s, void *d, int silent) 251 { 252 struct efs_sb_info *sb; 253 struct buffer_head *bh; 254 struct inode *root; 255 256 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL); 257 if (!sb) 258 return -ENOMEM; 259 s->s_fs_info = sb; 260 s->s_time_min = 0; 261 s->s_time_max = U32_MAX; 262 263 s->s_magic = EFS_SUPER_MAGIC; 264 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) { 265 pr_err("device does not support %d byte blocks\n", 266 EFS_BLOCKSIZE); 267 return -EINVAL; 268 } 269 270 /* read the vh (volume header) block */ 271 bh = sb_bread(s, 0); 272 273 if (!bh) { 274 pr_err("cannot read volume header\n"); 275 return -EIO; 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 return -EINVAL; 288 } 289 290 bh = sb_bread(s, sb->fs_start + EFS_SUPER); 291 if (!bh) { 292 pr_err("cannot read superblock\n"); 293 return -EIO; 294 } 295 296 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) { 297 #ifdef DEBUG 298 pr_warn("invalid superblock at block %u\n", 299 sb->fs_start + EFS_SUPER); 300 #endif 301 brelse(bh); 302 return -EINVAL; 303 } 304 brelse(bh); 305 306 if (!sb_rdonly(s)) { 307 #ifdef DEBUG 308 pr_info("forcing read-only mode\n"); 309 #endif 310 s->s_flags |= SB_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 pr_err("get root inode failed\n"); 317 return PTR_ERR(root); 318 } 319 320 s->s_root = d_make_root(root); 321 if (!(s->s_root)) { 322 pr_err("get root dentry failed\n"); 323 return -ENOMEM; 324 } 325 326 return 0; 327 } 328 329 static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) { 330 struct super_block *sb = dentry->d_sb; 331 struct efs_sb_info *sbi = SUPER_INFO(sb); 332 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 333 334 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */ 335 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */ 336 buf->f_blocks = sbi->total_groups * /* total data blocks */ 337 (sbi->group_size - sbi->inode_blocks); 338 buf->f_bfree = sbi->data_free; /* free data blocks */ 339 buf->f_bavail = sbi->data_free; /* free blocks for non-root */ 340 buf->f_files = sbi->total_groups * /* total inodes */ 341 sbi->inode_blocks * 342 (EFS_BLOCKSIZE / sizeof(struct efs_dinode)); 343 buf->f_ffree = sbi->inode_free; /* free inodes */ 344 buf->f_fsid.val[0] = (u32)id; 345 buf->f_fsid.val[1] = (u32)(id >> 32); 346 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */ 347 348 return 0; 349 } 350 351