fs/hfs/super.c

   1 /*
   2  *  linux/fs/hfs/super.c
   3  *
   4  * Copyright (C) 1995-1997  Paul H. Hargrove
   5  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   6  * This file may be distributed under the terms of the GNU General Public License.
   7  *
   8  * This file contains hfs_read_super(), some of the super_ops and
   9  * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
  10  * inode.c since they deal with inodes.
  11  *
  12  * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/blkdev.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/fs_context.h>
  19 #include <linux/fs_parser.h>
  20 #include <linux/mount.h>
  21 #include <linux/init.h>
  22 #include <linux/nls.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/slab.h>
  25 #include <linux/vfs.h>
  26
  27 #include "hfs_fs.h"
  28 #include "btree.h"
  29
  30 static struct kmem_cache *hfs_inode_cachep;
  31
  32 MODULE_DESCRIPTION("Apple Macintosh file system support");
  33 MODULE_LICENSE("GPL");
  34
  35 static int hfs_sync_fs(struct super_block *sb, int wait)
  36 {
  37         hfs_mdb_commit(sb);
  38         return 0;
  39 }
  40
  41 /*
  42  * hfs_put_super()
  43  *
  44  * This is the put_super() entry in the super_operations structure for
  45  * HFS filesystems.  The purpose is to release the resources
  46  * associated with the superblock sb.
  47  */
  48 static void hfs_put_super(struct super_block *sb)
  49 {
  50         cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
  51         hfs_mdb_close(sb);
  52         /* release the MDB's resources */
  53         hfs_mdb_put(sb);
  54 }
  55
  56 static void flush_mdb(struct work_struct *work)
  57 {
  58         struct hfs_sb_info *sbi;
  59         struct super_block *sb;
  60
  61         sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
  62         sb = sbi->sb;
  63
  64         spin_lock(&sbi->work_lock);
  65         sbi->work_queued = 0;
  66         spin_unlock(&sbi->work_lock);
  67
  68         hfs_mdb_commit(sb);
  69 }
  70
  71 void hfs_mark_mdb_dirty(struct super_block *sb)
  72 {
  73         struct hfs_sb_info *sbi = HFS_SB(sb);
  74         unsigned long delay;
  75
  76         if (sb_rdonly(sb))
  77                 return;
  78
  79         spin_lock(&sbi->work_lock);
  80         if (!sbi->work_queued) {
  81                 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
  82                 queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
  83                 sbi->work_queued = 1;
  84         }
  85         spin_unlock(&sbi->work_lock);
  86 }
  87
  88 /*
  89  * hfs_statfs()
  90  *
  91  * This is the statfs() entry in the super_operations structure for
  92  * HFS filesystems.  The purpose is to return various data about the
  93  * filesystem.
  94  *
  95  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  96  */
  97 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  98 {
  99         struct super_block *sb = dentry->d_sb;
 100         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 101
 102         buf->f_type = HFS_SUPER_MAGIC;
 103         buf->f_bsize = sb->s_blocksize;
 104         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
 105         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
 106         buf->f_bavail = buf->f_bfree;
 107         buf->f_files = HFS_SB(sb)->fs_ablocks;
 108         buf->f_ffree = HFS_SB(sb)->free_ablocks;
 109         buf->f_fsid = u64_to_fsid(id);
 110         buf->f_namelen = HFS_NAMELEN;
 111
 112         return 0;
 113 }
 114
 115 static int hfs_reconfigure(struct fs_context *fc)
 116 {
 117         struct super_block *sb = fc->root->d_sb;
 118
 119         sync_filesystem(sb);
 120         fc->sb_flags |= SB_NODIRATIME;
 121         if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
 122                 return 0;
 123
 124         if (!(fc->sb_flags & SB_RDONLY)) {
 125                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
 126                         pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
 127                         sb->s_flags |= SB_RDONLY;
 128                         fc->sb_flags |= SB_RDONLY;
 129                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
 130                         pr_warn("filesystem is marked locked, leaving read-only.\n");
 131                         sb->s_flags |= SB_RDONLY;
 132                         fc->sb_flags |= SB_RDONLY;
 133                 }
 134         }
 135         return 0;
 136 }
 137
 138 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
 139 {
 140         struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 141
 142         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
 143                 seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
 144         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
 145                 seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
 146         seq_printf(seq, ",uid=%u,gid=%u",
 147                         from_kuid_munged(&init_user_ns, sbi->s_uid),
 148                         from_kgid_munged(&init_user_ns, sbi->s_gid));
 149         if (sbi->s_file_umask != 0133)
 150                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
 151         if (sbi->s_dir_umask != 0022)
 152                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
 153         if (sbi->part >= 0)
 154                 seq_printf(seq, ",part=%u", sbi->part);
 155         if (sbi->session >= 0)
 156                 seq_printf(seq, ",session=%u", sbi->session);
 157         if (sbi->nls_disk)
 158                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
 159         if (sbi->nls_io)
 160                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
 161         if (sbi->s_quiet)
 162                 seq_printf(seq, ",quiet");
 163         return 0;
 164 }
 165
 166 static struct inode *hfs_alloc_inode(struct super_block *sb)
 167 {
 168         struct hfs_inode_info *i;
 169
 170         i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
 171         return i ? &i->vfs_inode : NULL;
 172 }
 173
 174 static void hfs_free_inode(struct inode *inode)
 175 {
 176         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
 177 }
 178
 179 static const struct super_operations hfs_super_operations = {
 180         .alloc_inode    = hfs_alloc_inode,
 181         .free_inode     = hfs_free_inode,
 182         .write_inode    = hfs_write_inode,
 183         .evict_inode    = hfs_evict_inode,
 184         .put_super      = hfs_put_super,
 185         .sync_fs        = hfs_sync_fs,
 186         .statfs         = hfs_statfs,
 187         .show_options   = hfs_show_options,
 188 };
 189
 190 enum {
 191         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
 192         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
 193         opt_codepage, opt_iocharset,
 194 };
 195
 196 static const struct fs_parameter_spec hfs_param_spec[] = {
 197         fsparam_u32     ("uid",         opt_uid),
 198         fsparam_u32     ("gid",         opt_gid),
 199         fsparam_u32oct  ("umask",       opt_umask),
 200         fsparam_u32oct  ("file_umask",  opt_file_umask),
 201         fsparam_u32oct  ("dir_umask",   opt_dir_umask),
 202         fsparam_u32     ("part",        opt_part),
 203         fsparam_u32     ("session",     opt_session),
 204         fsparam_string  ("type",        opt_type),
 205         fsparam_string  ("creator",     opt_creator),
 206         fsparam_flag    ("quiet",       opt_quiet),
 207         fsparam_string  ("codepage",    opt_codepage),
 208         fsparam_string  ("iocharset",   opt_iocharset),
 209         {}
 210 };
 211
 212 /*
 213  * hfs_parse_param()
 214  *
 215  * This function is called by the vfs to parse the mount options.
 216  */
 217 static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 218 {
 219         struct hfs_sb_info *hsb = fc->s_fs_info;
 220         struct fs_parse_result result;
 221         int opt;
 222
 223         /* hfs does not honor any fs-specific options on remount */
 224         if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
 225                 return 0;
 226
 227         opt = fs_parse(fc, hfs_param_spec, param, &result);
 228         if (opt < 0)
 229                 return opt;
 230
 231         switch (opt) {
 232         case opt_uid:
 233                 hsb->s_uid = result.uid;
 234                 break;
 235         case opt_gid:
 236                 hsb->s_gid = result.gid;
 237                 break;
 238         case opt_umask:
 239                 hsb->s_file_umask = (umode_t)result.uint_32;
 240                 hsb->s_dir_umask = (umode_t)result.uint_32;
 241                 break;
 242         case opt_file_umask:
 243                 hsb->s_file_umask = (umode_t)result.uint_32;
 244                 break;
 245         case opt_dir_umask:
 246                 hsb->s_dir_umask = (umode_t)result.uint_32;
 247                 break;
 248         case opt_part:
 249                 hsb->part = result.uint_32;
 250                 break;
 251         case opt_session:
 252                 hsb->session = result.uint_32;
 253                 break;
 254         case opt_type:
 255                 if (strlen(param->string) != 4) {
 256                         pr_err("type requires a 4 character value\n");
 257                         return -EINVAL;
 258                 }
 259                 memcpy(&hsb->s_type, param->string, 4);
 260                 break;
 261         case opt_creator:
 262                 if (strlen(param->string) != 4) {
 263                         pr_err("creator requires a 4 character value\n");
 264                         return -EINVAL;
 265                 }
 266                 memcpy(&hsb->s_creator, param->string, 4);
 267                 break;
 268         case opt_quiet:
 269                 hsb->s_quiet = 1;
 270                 break;
 271         case opt_codepage:
 272                 if (hsb->nls_disk) {
 273                         pr_err("unable to change codepage\n");
 274                         return -EINVAL;
 275                 }
 276                 hsb->nls_disk = load_nls(param->string);
 277                 if (!hsb->nls_disk) {
 278                         pr_err("unable to load codepage \"%s\"\n",
 279                                         param->string);
 280                         return -EINVAL;
 281                 }
 282                 break;
 283         case opt_iocharset:
 284                 if (hsb->nls_io) {
 285                         pr_err("unable to change iocharset\n");
 286                         return -EINVAL;
 287                 }
 288                 hsb->nls_io = load_nls(param->string);
 289                 if (!hsb->nls_io) {
 290                         pr_err("unable to load iocharset \"%s\"\n",
 291                                         param->string);
 292                         return -EINVAL;
 293                 }
 294                 break;
 295         default:
 296                 return -EINVAL;
 297         }
 298
 299         return 0;
 300 }
 301
 302 /*
 303  * hfs_read_super()
 304  *
 305  * This is the function that is responsible for mounting an HFS
 306  * filesystem.  It performs all the tasks necessary to get enough data
 307  * from the disk to read the root inode.  This includes parsing the
 308  * mount options, dealing with Macintosh partitions, reading the
 309  * superblock and the allocation bitmap blocks, calling
 310  * hfs_btree_init() to get the necessary data about the extents and
 311  * catalog B-trees and, finally, reading the root inode into memory.
 312  */
 313 static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
 314 {
 315         struct hfs_sb_info *sbi = HFS_SB(sb);
 316         struct hfs_find_data fd;
 317         hfs_cat_rec rec;
 318         struct inode *root_inode;
 319         int silent = fc->sb_flags & SB_SILENT;
 320         int res;
 321
 322         /* load_nls_default does not fail */
 323         if (sbi->nls_disk && !sbi->nls_io)
 324                 sbi->nls_io = load_nls_default();
 325         sbi->s_dir_umask &= 0777;
 326         sbi->s_file_umask &= 0577;
 327
 328         spin_lock_init(&sbi->work_lock);
 329         INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
 330
 331         sbi->sb = sb;
 332         sb->s_op = &hfs_super_operations;
 333         sb->s_xattr = hfs_xattr_handlers;
 334         sb->s_flags |= SB_NODIRATIME;
 335         mutex_init(&sbi->bitmap_lock);
 336
 337         res = hfs_mdb_get(sb);
 338         if (res) {
 339                 if (!silent)
 340                         pr_warn("can't find a HFS filesystem on dev %s\n",
 341                                 hfs_mdb_name(sb));
 342                 res = -EINVAL;
 343                 goto bail;
 344         }
 345
 346         /* try to get the root inode */
 347         res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 348         if (res)
 349                 goto bail_no_root;
 350         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
 351         if (!res) {
 352                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
 353                         res =  -EIO;
 354                         goto bail_hfs_find;
 355                 }
 356                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
 357         }
 358         if (res)
 359                 goto bail_hfs_find;
 360         res = -EINVAL;
 361         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
 362         hfs_find_exit(&fd);
 363         if (!root_inode)
 364                 goto bail_no_root;
 365
 366         sb->s_d_op = &hfs_dentry_operations;
 367         res = -ENOMEM;
 368         sb->s_root = d_make_root(root_inode);
 369         if (!sb->s_root)
 370                 goto bail_no_root;
 371
 372         /* everything's okay */
 373         return 0;
 374
 375 bail_hfs_find:
 376         hfs_find_exit(&fd);
 377 bail_no_root:
 378         pr_err("get root inode failed\n");
 379 bail:
 380         hfs_mdb_put(sb);
 381         return res;
 382 }
 383
 384 static int hfs_get_tree(struct fs_context *fc)
 385 {
 386         return get_tree_bdev(fc, hfs_fill_super);
 387 }
 388
 389 static void hfs_free_fc(struct fs_context *fc)
 390 {
 391         kfree(fc->s_fs_info);
 392 }
 393
 394 static const struct fs_context_operations hfs_context_ops = {
 395         .parse_param    = hfs_parse_param,
 396         .get_tree       = hfs_get_tree,
 397         .reconfigure    = hfs_reconfigure,
 398         .free           = hfs_free_fc,
 399 };
 400
 401 static int hfs_init_fs_context(struct fs_context *fc)
 402 {
 403         struct hfs_sb_info *hsb;
 404
 405         hsb = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
 406         if (!hsb)
 407                 return -ENOMEM;
 408
 409         fc->s_fs_info = hsb;
 410         fc->ops = &hfs_context_ops;
 411
 412         if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
 413                 /* initialize options with defaults */
 414                 hsb->s_uid = current_uid();
 415                 hsb->s_gid = current_gid();
 416                 hsb->s_file_umask = 0133;
 417                 hsb->s_dir_umask = 0022;
 418                 hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 419                 hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
 420                 hsb->s_quiet = 0;
 421                 hsb->part = -1;
 422                 hsb->session = -1;
 423         }
 424
 425         return 0;
 426 }
 427
 428 static struct file_system_type hfs_fs_type = {
 429         .owner          = THIS_MODULE,
 430         .name           = "hfs",
 431         .kill_sb        = kill_block_super,
 432         .fs_flags       = FS_REQUIRES_DEV,
 433         .init_fs_context = hfs_init_fs_context,
 434 };
 435 MODULE_ALIAS_FS("hfs");
 436
 437 static void hfs_init_once(void *p)
 438 {
 439         struct hfs_inode_info *i = p;
 440
 441         inode_init_once(&i->vfs_inode);
 442 }
 443
 444 static int __init init_hfs_fs(void)
 445 {
 446         int err;
 447
 448         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
 449                 sizeof(struct hfs_inode_info), 0,
 450                 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
 451         if (!hfs_inode_cachep)
 452                 return -ENOMEM;
 453         err = register_filesystem(&hfs_fs_type);
 454         if (err)
 455                 kmem_cache_destroy(hfs_inode_cachep);
 456         return err;
 457 }
 458
 459 static void __exit exit_hfs_fs(void)
 460 {
 461         unregister_filesystem(&hfs_fs_type);
 462
 463         /*
 464          * Make sure all delayed rcu free inodes are flushed before we
 465          * destroy cache.
 466          */
 467         rcu_barrier();
 468         kmem_cache_destroy(hfs_inode_cachep);
 469 }
 470
 471 module_init(init_hfs_fs)
 472 module_exit(exit_hfs_fs)