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1// SPDX-License-Identifier: GPL-2.02/*3 * super.c4 *5 * Copyright (c) 1999 Al Smith6 *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#include <linux/blkdev.h>17#include <linux/fs_context.h>18#include <linux/fs_parser.h>19#include "efs.h"20#include <linux/efs_vh.h>21#include <linux/efs_fs_sb.h>22 23static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);24static int efs_init_fs_context(struct fs_context *fc);25 26static void efs_kill_sb(struct super_block *s)27{28 struct efs_sb_info *sbi = SUPER_INFO(s);29 kill_block_super(s);30 kfree(sbi);31}32 33static struct pt_types sgi_pt_types[] = {34 {0x00, "SGI vh"},35 {0x01, "SGI trkrepl"},36 {0x02, "SGI secrepl"},37 {0x03, "SGI raw"},38 {0x04, "SGI bsd"},39 {SGI_SYSV, "SGI sysv"},40 {0x06, "SGI vol"},41 {SGI_EFS, "SGI efs"},42 {0x08, "SGI lv"},43 {0x09, "SGI rlv"},44 {0x0A, "SGI xfs"},45 {0x0B, "SGI xfslog"},46 {0x0C, "SGI xlv"},47 {0x82, "Linux swap"},48 {0x83, "Linux native"},49 {0, NULL}50};51 52enum {53 Opt_explicit_open,54};55 56static const struct fs_parameter_spec efs_param_spec[] = {57 fsparam_flag ("explicit-open", Opt_explicit_open),58 {}59};60 61/*62 * File system definition and registration.63 */64static struct file_system_type efs_fs_type = {65 .owner = THIS_MODULE,66 .name = "efs",67 .kill_sb = efs_kill_sb,68 .fs_flags = FS_REQUIRES_DEV,69 .init_fs_context = efs_init_fs_context,70 .parameters = efs_param_spec,71};72MODULE_ALIAS_FS("efs");73 74static struct kmem_cache * efs_inode_cachep;75 76static struct inode *efs_alloc_inode(struct super_block *sb)77{78 struct efs_inode_info *ei;79 ei = alloc_inode_sb(sb, efs_inode_cachep, GFP_KERNEL);80 if (!ei)81 return NULL;82 return &ei->vfs_inode;83}84 85static void efs_free_inode(struct inode *inode)86{87 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));88}89 90static void init_once(void *foo)91{92 struct efs_inode_info *ei = (struct efs_inode_info *) foo;93 94 inode_init_once(&ei->vfs_inode);95}96 97static int __init init_inodecache(void)98{99 efs_inode_cachep = kmem_cache_create("efs_inode_cache",100 sizeof(struct efs_inode_info), 0,101 SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,102 init_once);103 if (efs_inode_cachep == NULL)104 return -ENOMEM;105 return 0;106}107 108static void destroy_inodecache(void)109{110 /*111 * Make sure all delayed rcu free inodes are flushed before we112 * destroy cache.113 */114 rcu_barrier();115 kmem_cache_destroy(efs_inode_cachep);116}117 118static const struct super_operations efs_superblock_operations = {119 .alloc_inode = efs_alloc_inode,120 .free_inode = efs_free_inode,121 .statfs = efs_statfs,122};123 124static const struct export_operations efs_export_ops = {125 .encode_fh = generic_encode_ino32_fh,126 .fh_to_dentry = efs_fh_to_dentry,127 .fh_to_parent = efs_fh_to_parent,128 .get_parent = efs_get_parent,129};130 131static int __init init_efs_fs(void) {132 int err;133 pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");134 err = init_inodecache();135 if (err)136 goto out1;137 err = register_filesystem(&efs_fs_type);138 if (err)139 goto out;140 return 0;141out:142 destroy_inodecache();143out1:144 return err;145}146 147static void __exit exit_efs_fs(void) {148 unregister_filesystem(&efs_fs_type);149 destroy_inodecache();150}151 152module_init(init_efs_fs)153module_exit(exit_efs_fs)154 155static efs_block_t efs_validate_vh(struct volume_header *vh) {156 int i;157 __be32 cs, *ui;158 int csum;159 efs_block_t sblock = 0; /* shuts up gcc */160 struct pt_types *pt_entry;161 int pt_type, slice = -1;162 163 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {164 /*165 * assume that we're dealing with a partition and allow166 * read_super() to try and detect a valid superblock167 * on the next block.168 */169 return 0;170 }171 172 ui = ((__be32 *) (vh + 1)) - 1;173 for(csum = 0; ui >= ((__be32 *) vh);) {174 cs = *ui--;175 csum += be32_to_cpu(cs);176 }177 if (csum) {178 pr_warn("SGI disklabel: checksum bad, label corrupted\n");179 return 0;180 }181 182#ifdef DEBUG183 pr_debug("bf: \"%16s\"\n", vh->vh_bootfile);184 185 for(i = 0; i < NVDIR; i++) {186 int j;187 char name[VDNAMESIZE+1];188 189 for(j = 0; j < VDNAMESIZE; j++) {190 name[j] = vh->vh_vd[i].vd_name[j];191 }192 name[j] = (char) 0;193 194 if (name[0]) {195 pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n",196 name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),197 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));198 }199 }200#endif201 202 for(i = 0; i < NPARTAB; i++) {203 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);204 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {205 if (pt_type == pt_entry->pt_type) break;206 }207#ifdef DEBUG208 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {209 pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",210 i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn),211 (int)be32_to_cpu(vh->vh_pt[i].pt_nblks),212 pt_type, (pt_entry->pt_name) ?213 pt_entry->pt_name : "unknown");214 }215#endif216 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 pr_notice("partition table contained no EFS partitions\n");224#ifdef DEBUG225 } else {226 pr_info("using slice %d (type %s, offset 0x%x)\n", slice,227 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown",228 sblock);229#endif230 }231 return sblock;232}233 234static 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 251static int efs_fill_super(struct super_block *s, struct fs_context *fc)252{253 struct efs_sb_info *sb;254 struct buffer_head *bh;255 struct inode *root;256 257 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);258 if (!sb)259 return -ENOMEM;260 s->s_fs_info = sb;261 s->s_time_min = 0;262 s->s_time_max = U32_MAX;263 264 s->s_magic = EFS_SUPER_MAGIC;265 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {266 pr_err("device does not support %d byte blocks\n",267 EFS_BLOCKSIZE);268 return -EINVAL;269 }270 271 /* read the vh (volume header) block */272 bh = sb_bread(s, 0);273 274 if (!bh) {275 pr_err("cannot read volume header\n");276 return -EIO;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 that282 * 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 return -EINVAL;289 }290 291 bh = sb_bread(s, sb->fs_start + EFS_SUPER);292 if (!bh) {293 pr_err("cannot read superblock\n");294 return -EIO;295 }296 297 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {298#ifdef DEBUG299 pr_warn("invalid superblock at block %u\n",300 sb->fs_start + EFS_SUPER);301#endif302 brelse(bh);303 return -EINVAL;304 }305 brelse(bh);306 307 if (!sb_rdonly(s)) {308#ifdef DEBUG309 pr_info("forcing read-only mode\n");310#endif311 s->s_flags |= SB_RDONLY;312 }313 s->s_op = &efs_superblock_operations;314 s->s_export_op = &efs_export_ops;315 root = efs_iget(s, EFS_ROOTINODE);316 if (IS_ERR(root)) {317 pr_err("get root inode failed\n");318 return PTR_ERR(root);319 }320 321 s->s_root = d_make_root(root);322 if (!(s->s_root)) {323 pr_err("get root dentry failed\n");324 return -ENOMEM;325 }326 327 return 0;328}329 330static void efs_free_fc(struct fs_context *fc)331{332 kfree(fc->fs_private);333}334 335static int efs_get_tree(struct fs_context *fc)336{337 return get_tree_bdev(fc, efs_fill_super);338}339 340static int efs_parse_param(struct fs_context *fc, struct fs_parameter *param)341{342 int token;343 struct fs_parse_result result;344 345 token = fs_parse(fc, efs_param_spec, param, &result);346 if (token < 0)347 return token;348 return 0;349}350 351static int efs_reconfigure(struct fs_context *fc)352{353 sync_filesystem(fc->root->d_sb);354 355 return 0;356}357 358struct efs_context {359 unsigned long s_mount_opts;360};361 362static const struct fs_context_operations efs_context_opts = {363 .parse_param = efs_parse_param,364 .get_tree = efs_get_tree,365 .reconfigure = efs_reconfigure,366 .free = efs_free_fc,367};368 369/*370 * Set up the filesystem mount context.371 */372static int efs_init_fs_context(struct fs_context *fc)373{374 struct efs_context *ctx;375 376 ctx = kzalloc(sizeof(struct efs_context), GFP_KERNEL);377 if (!ctx)378 return -ENOMEM;379 fc->fs_private = ctx;380 fc->ops = &efs_context_opts;381 382 return 0;383}384 385static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {386 struct super_block *sb = dentry->d_sb;387 struct efs_sb_info *sbi = SUPER_INFO(sb);388 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);389 390 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */391 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */392 buf->f_blocks = sbi->total_groups * /* total data blocks */393 (sbi->group_size - sbi->inode_blocks);394 buf->f_bfree = sbi->data_free; /* free data blocks */395 buf->f_bavail = sbi->data_free; /* free blocks for non-root */396 buf->f_files = sbi->total_groups * /* total inodes */397 sbi->inode_blocks *398 (EFS_BLOCKSIZE / sizeof(struct efs_dinode));399 buf->f_ffree = sbi->inode_free; /* free inodes */400 buf->f_fsid = u64_to_fsid(id);401 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */402 403 return 0;404}405 406