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0001 /*
0002  *  linux/fs/hfs/super.c
0003  *
0004  * Copyright (C) 1995-1997  Paul H. Hargrove
0005  * (C) 2003 Ardis Technologies <roman@ardistech.com>
0006  * This file may be distributed under the terms of the GNU General Public License.
0007  *
0008  * This file contains hfs_read_super(), some of the super_ops and
0009  * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
0010  * inode.c since they deal with inodes.
0011  *
0012  * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
0013  */
0014 
0015 #include <linux/module.h>
0016 #include <linux/blkdev.h>
0017 #include <linux/backing-dev.h>
0018 #include <linux/mount.h>
0019 #include <linux/init.h>
0020 #include <linux/nls.h>
0021 #include <linux/parser.h>
0022 #include <linux/seq_file.h>
0023 #include <linux/slab.h>
0024 #include <linux/vfs.h>
0025 
0026 #include "hfs_fs.h"
0027 #include "btree.h"
0028 
0029 static struct kmem_cache *hfs_inode_cachep;
0030 
0031 MODULE_LICENSE("GPL");
0032 
0033 static int hfs_sync_fs(struct super_block *sb, int wait)
0034 {
0035     hfs_mdb_commit(sb);
0036     return 0;
0037 }
0038 
0039 /*
0040  * hfs_put_super()
0041  *
0042  * This is the put_super() entry in the super_operations structure for
0043  * HFS filesystems.  The purpose is to release the resources
0044  * associated with the superblock sb.
0045  */
0046 static void hfs_put_super(struct super_block *sb)
0047 {
0048     cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
0049     hfs_mdb_close(sb);
0050     /* release the MDB's resources */
0051     hfs_mdb_put(sb);
0052 }
0053 
0054 static void flush_mdb(struct work_struct *work)
0055 {
0056     struct hfs_sb_info *sbi;
0057     struct super_block *sb;
0058 
0059     sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
0060     sb = sbi->sb;
0061 
0062     spin_lock(&sbi->work_lock);
0063     sbi->work_queued = 0;
0064     spin_unlock(&sbi->work_lock);
0065 
0066     hfs_mdb_commit(sb);
0067 }
0068 
0069 void hfs_mark_mdb_dirty(struct super_block *sb)
0070 {
0071     struct hfs_sb_info *sbi = HFS_SB(sb);
0072     unsigned long delay;
0073 
0074     if (sb_rdonly(sb))
0075         return;
0076 
0077     spin_lock(&sbi->work_lock);
0078     if (!sbi->work_queued) {
0079         delay = msecs_to_jiffies(dirty_writeback_interval * 10);
0080         queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
0081         sbi->work_queued = 1;
0082     }
0083     spin_unlock(&sbi->work_lock);
0084 }
0085 
0086 /*
0087  * hfs_statfs()
0088  *
0089  * This is the statfs() entry in the super_operations structure for
0090  * HFS filesystems.  The purpose is to return various data about the
0091  * filesystem.
0092  *
0093  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
0094  */
0095 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
0096 {
0097     struct super_block *sb = dentry->d_sb;
0098     u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
0099 
0100     buf->f_type = HFS_SUPER_MAGIC;
0101     buf->f_bsize = sb->s_blocksize;
0102     buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
0103     buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
0104     buf->f_bavail = buf->f_bfree;
0105     buf->f_files = HFS_SB(sb)->fs_ablocks;
0106     buf->f_ffree = HFS_SB(sb)->free_ablocks;
0107     buf->f_fsid = u64_to_fsid(id);
0108     buf->f_namelen = HFS_NAMELEN;
0109 
0110     return 0;
0111 }
0112 
0113 static int hfs_remount(struct super_block *sb, int *flags, char *data)
0114 {
0115     sync_filesystem(sb);
0116     *flags |= SB_NODIRATIME;
0117     if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
0118         return 0;
0119     if (!(*flags & SB_RDONLY)) {
0120         if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
0121             pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
0122             sb->s_flags |= SB_RDONLY;
0123             *flags |= SB_RDONLY;
0124         } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
0125             pr_warn("filesystem is marked locked, leaving read-only.\n");
0126             sb->s_flags |= SB_RDONLY;
0127             *flags |= SB_RDONLY;
0128         }
0129     }
0130     return 0;
0131 }
0132 
0133 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
0134 {
0135     struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
0136 
0137     if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
0138         seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
0139     if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
0140         seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
0141     seq_printf(seq, ",uid=%u,gid=%u",
0142             from_kuid_munged(&init_user_ns, sbi->s_uid),
0143             from_kgid_munged(&init_user_ns, sbi->s_gid));
0144     if (sbi->s_file_umask != 0133)
0145         seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
0146     if (sbi->s_dir_umask != 0022)
0147         seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
0148     if (sbi->part >= 0)
0149         seq_printf(seq, ",part=%u", sbi->part);
0150     if (sbi->session >= 0)
0151         seq_printf(seq, ",session=%u", sbi->session);
0152     if (sbi->nls_disk)
0153         seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
0154     if (sbi->nls_io)
0155         seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
0156     if (sbi->s_quiet)
0157         seq_printf(seq, ",quiet");
0158     return 0;
0159 }
0160 
0161 static struct inode *hfs_alloc_inode(struct super_block *sb)
0162 {
0163     struct hfs_inode_info *i;
0164 
0165     i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
0166     return i ? &i->vfs_inode : NULL;
0167 }
0168 
0169 static void hfs_free_inode(struct inode *inode)
0170 {
0171     kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
0172 }
0173 
0174 static const struct super_operations hfs_super_operations = {
0175     .alloc_inode    = hfs_alloc_inode,
0176     .free_inode = hfs_free_inode,
0177     .write_inode    = hfs_write_inode,
0178     .evict_inode    = hfs_evict_inode,
0179     .put_super  = hfs_put_super,
0180     .sync_fs    = hfs_sync_fs,
0181     .statfs     = hfs_statfs,
0182     .remount_fs     = hfs_remount,
0183     .show_options   = hfs_show_options,
0184 };
0185 
0186 enum {
0187     opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
0188     opt_part, opt_session, opt_type, opt_creator, opt_quiet,
0189     opt_codepage, opt_iocharset,
0190     opt_err
0191 };
0192 
0193 static const match_table_t tokens = {
0194     { opt_uid, "uid=%u" },
0195     { opt_gid, "gid=%u" },
0196     { opt_umask, "umask=%o" },
0197     { opt_file_umask, "file_umask=%o" },
0198     { opt_dir_umask, "dir_umask=%o" },
0199     { opt_part, "part=%u" },
0200     { opt_session, "session=%u" },
0201     { opt_type, "type=%s" },
0202     { opt_creator, "creator=%s" },
0203     { opt_quiet, "quiet" },
0204     { opt_codepage, "codepage=%s" },
0205     { opt_iocharset, "iocharset=%s" },
0206     { opt_err, NULL }
0207 };
0208 
0209 static inline int match_fourchar(substring_t *arg, u32 *result)
0210 {
0211     if (arg->to - arg->from != 4)
0212         return -EINVAL;
0213     memcpy(result, arg->from, 4);
0214     return 0;
0215 }
0216 
0217 /*
0218  * parse_options()
0219  *
0220  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
0221  * This function is called by hfs_read_super() to parse the mount options.
0222  */
0223 static int parse_options(char *options, struct hfs_sb_info *hsb)
0224 {
0225     char *p;
0226     substring_t args[MAX_OPT_ARGS];
0227     int tmp, token;
0228 
0229     /* initialize the sb with defaults */
0230     hsb->s_uid = current_uid();
0231     hsb->s_gid = current_gid();
0232     hsb->s_file_umask = 0133;
0233     hsb->s_dir_umask = 0022;
0234     hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
0235     hsb->s_quiet = 0;
0236     hsb->part = -1;
0237     hsb->session = -1;
0238 
0239     if (!options)
0240         return 1;
0241 
0242     while ((p = strsep(&options, ",")) != NULL) {
0243         if (!*p)
0244             continue;
0245 
0246         token = match_token(p, tokens, args);
0247         switch (token) {
0248         case opt_uid:
0249             if (match_int(&args[0], &tmp)) {
0250                 pr_err("uid requires an argument\n");
0251                 return 0;
0252             }
0253             hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
0254             if (!uid_valid(hsb->s_uid)) {
0255                 pr_err("invalid uid %d\n", tmp);
0256                 return 0;
0257             }
0258             break;
0259         case opt_gid:
0260             if (match_int(&args[0], &tmp)) {
0261                 pr_err("gid requires an argument\n");
0262                 return 0;
0263             }
0264             hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
0265             if (!gid_valid(hsb->s_gid)) {
0266                 pr_err("invalid gid %d\n", tmp);
0267                 return 0;
0268             }
0269             break;
0270         case opt_umask:
0271             if (match_octal(&args[0], &tmp)) {
0272                 pr_err("umask requires a value\n");
0273                 return 0;
0274             }
0275             hsb->s_file_umask = (umode_t)tmp;
0276             hsb->s_dir_umask = (umode_t)tmp;
0277             break;
0278         case opt_file_umask:
0279             if (match_octal(&args[0], &tmp)) {
0280                 pr_err("file_umask requires a value\n");
0281                 return 0;
0282             }
0283             hsb->s_file_umask = (umode_t)tmp;
0284             break;
0285         case opt_dir_umask:
0286             if (match_octal(&args[0], &tmp)) {
0287                 pr_err("dir_umask requires a value\n");
0288                 return 0;
0289             }
0290             hsb->s_dir_umask = (umode_t)tmp;
0291             break;
0292         case opt_part:
0293             if (match_int(&args[0], &hsb->part)) {
0294                 pr_err("part requires an argument\n");
0295                 return 0;
0296             }
0297             break;
0298         case opt_session:
0299             if (match_int(&args[0], &hsb->session)) {
0300                 pr_err("session requires an argument\n");
0301                 return 0;
0302             }
0303             break;
0304         case opt_type:
0305             if (match_fourchar(&args[0], &hsb->s_type)) {
0306                 pr_err("type requires a 4 character value\n");
0307                 return 0;
0308             }
0309             break;
0310         case opt_creator:
0311             if (match_fourchar(&args[0], &hsb->s_creator)) {
0312                 pr_err("creator requires a 4 character value\n");
0313                 return 0;
0314             }
0315             break;
0316         case opt_quiet:
0317             hsb->s_quiet = 1;
0318             break;
0319         case opt_codepage:
0320             if (hsb->nls_disk) {
0321                 pr_err("unable to change codepage\n");
0322                 return 0;
0323             }
0324             p = match_strdup(&args[0]);
0325             if (p)
0326                 hsb->nls_disk = load_nls(p);
0327             if (!hsb->nls_disk) {
0328                 pr_err("unable to load codepage \"%s\"\n", p);
0329                 kfree(p);
0330                 return 0;
0331             }
0332             kfree(p);
0333             break;
0334         case opt_iocharset:
0335             if (hsb->nls_io) {
0336                 pr_err("unable to change iocharset\n");
0337                 return 0;
0338             }
0339             p = match_strdup(&args[0]);
0340             if (p)
0341                 hsb->nls_io = load_nls(p);
0342             if (!hsb->nls_io) {
0343                 pr_err("unable to load iocharset \"%s\"\n", p);
0344                 kfree(p);
0345                 return 0;
0346             }
0347             kfree(p);
0348             break;
0349         default:
0350             return 0;
0351         }
0352     }
0353 
0354     if (hsb->nls_disk && !hsb->nls_io) {
0355         hsb->nls_io = load_nls_default();
0356         if (!hsb->nls_io) {
0357             pr_err("unable to load default iocharset\n");
0358             return 0;
0359         }
0360     }
0361     hsb->s_dir_umask &= 0777;
0362     hsb->s_file_umask &= 0577;
0363 
0364     return 1;
0365 }
0366 
0367 /*
0368  * hfs_read_super()
0369  *
0370  * This is the function that is responsible for mounting an HFS
0371  * filesystem.  It performs all the tasks necessary to get enough data
0372  * from the disk to read the root inode.  This includes parsing the
0373  * mount options, dealing with Macintosh partitions, reading the
0374  * superblock and the allocation bitmap blocks, calling
0375  * hfs_btree_init() to get the necessary data about the extents and
0376  * catalog B-trees and, finally, reading the root inode into memory.
0377  */
0378 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
0379 {
0380     struct hfs_sb_info *sbi;
0381     struct hfs_find_data fd;
0382     hfs_cat_rec rec;
0383     struct inode *root_inode;
0384     int res;
0385 
0386     sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
0387     if (!sbi)
0388         return -ENOMEM;
0389 
0390     sbi->sb = sb;
0391     sb->s_fs_info = sbi;
0392     spin_lock_init(&sbi->work_lock);
0393     INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
0394 
0395     res = -EINVAL;
0396     if (!parse_options((char *)data, sbi)) {
0397         pr_err("unable to parse mount options\n");
0398         goto bail;
0399     }
0400 
0401     sb->s_op = &hfs_super_operations;
0402     sb->s_xattr = hfs_xattr_handlers;
0403     sb->s_flags |= SB_NODIRATIME;
0404     mutex_init(&sbi->bitmap_lock);
0405 
0406     res = hfs_mdb_get(sb);
0407     if (res) {
0408         if (!silent)
0409             pr_warn("can't find a HFS filesystem on dev %s\n",
0410                 hfs_mdb_name(sb));
0411         res = -EINVAL;
0412         goto bail;
0413     }
0414 
0415     /* try to get the root inode */
0416     res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
0417     if (res)
0418         goto bail_no_root;
0419     res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
0420     if (!res) {
0421         if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
0422             res =  -EIO;
0423             goto bail_hfs_find;
0424         }
0425         hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
0426     }
0427     if (res)
0428         goto bail_hfs_find;
0429     res = -EINVAL;
0430     root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
0431     hfs_find_exit(&fd);
0432     if (!root_inode)
0433         goto bail_no_root;
0434 
0435     sb->s_d_op = &hfs_dentry_operations;
0436     res = -ENOMEM;
0437     sb->s_root = d_make_root(root_inode);
0438     if (!sb->s_root)
0439         goto bail_no_root;
0440 
0441     /* everything's okay */
0442     return 0;
0443 
0444 bail_hfs_find:
0445     hfs_find_exit(&fd);
0446 bail_no_root:
0447     pr_err("get root inode failed\n");
0448 bail:
0449     hfs_mdb_put(sb);
0450     return res;
0451 }
0452 
0453 static struct dentry *hfs_mount(struct file_system_type *fs_type,
0454               int flags, const char *dev_name, void *data)
0455 {
0456     return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
0457 }
0458 
0459 static struct file_system_type hfs_fs_type = {
0460     .owner      = THIS_MODULE,
0461     .name       = "hfs",
0462     .mount      = hfs_mount,
0463     .kill_sb    = kill_block_super,
0464     .fs_flags   = FS_REQUIRES_DEV,
0465 };
0466 MODULE_ALIAS_FS("hfs");
0467 
0468 static void hfs_init_once(void *p)
0469 {
0470     struct hfs_inode_info *i = p;
0471 
0472     inode_init_once(&i->vfs_inode);
0473 }
0474 
0475 static int __init init_hfs_fs(void)
0476 {
0477     int err;
0478 
0479     hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
0480         sizeof(struct hfs_inode_info), 0,
0481         SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
0482     if (!hfs_inode_cachep)
0483         return -ENOMEM;
0484     err = register_filesystem(&hfs_fs_type);
0485     if (err)
0486         kmem_cache_destroy(hfs_inode_cachep);
0487     return err;
0488 }
0489 
0490 static void __exit exit_hfs_fs(void)
0491 {
0492     unregister_filesystem(&hfs_fs_type);
0493 
0494     /*
0495      * Make sure all delayed rcu free inodes are flushed before we
0496      * destroy cache.
0497      */
0498     rcu_barrier();
0499     kmem_cache_destroy(hfs_inode_cachep);
0500 }
0501 
0502 module_init(init_hfs_fs)
0503 module_exit(exit_hfs_fs)
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