Root/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/mount.h>
18#include <linux/init.h>
19#include <linux/nls.h>
20#include <linux/parser.h>
21#include <linux/seq_file.h>
22#include <linux/slab.h>
23#include <linux/smp_lock.h>
24#include <linux/vfs.h>
25
26#include "hfs_fs.h"
27#include "btree.h"
28
29static struct kmem_cache *hfs_inode_cachep;
30
31MODULE_LICENSE("GPL");
32
33/*
34 * hfs_write_super()
35 *
36 * Description:
37 * This function is called by the VFS only. When the filesystem
38 * is mounted r/w it updates the MDB on disk.
39 * Input Variable(s):
40 * struct super_block *sb: Pointer to the hfs superblock
41 * Output Variable(s):
42 * NONE
43 * Returns:
44 * void
45 * Preconditions:
46 * 'sb' points to a "valid" (struct super_block).
47 * Postconditions:
48 * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
49 * (hfs_put_super() must set this flag!). Some MDB fields are updated
50 * and the MDB buffer is written to disk by calling hfs_mdb_commit().
51 */
52static void hfs_write_super(struct super_block *sb)
53{
54    lock_super(sb);
55    sb->s_dirt = 0;
56
57    /* sync everything to the buffers */
58    if (!(sb->s_flags & MS_RDONLY))
59        hfs_mdb_commit(sb);
60    unlock_super(sb);
61}
62
63static int hfs_sync_fs(struct super_block *sb, int wait)
64{
65    lock_super(sb);
66    hfs_mdb_commit(sb);
67    sb->s_dirt = 0;
68    unlock_super(sb);
69
70    return 0;
71}
72
73/*
74 * hfs_put_super()
75 *
76 * This is the put_super() entry in the super_operations structure for
77 * HFS filesystems. The purpose is to release the resources
78 * associated with the superblock sb.
79 */
80static void hfs_put_super(struct super_block *sb)
81{
82    lock_kernel();
83
84    if (sb->s_dirt)
85        hfs_write_super(sb);
86    hfs_mdb_close(sb);
87    /* release the MDB's resources */
88    hfs_mdb_put(sb);
89
90    unlock_kernel();
91}
92
93/*
94 * hfs_statfs()
95 *
96 * This is the statfs() entry in the super_operations structure for
97 * HFS filesystems. The purpose is to return various data about the
98 * filesystem.
99 *
100 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
101 */
102static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
103{
104    struct super_block *sb = dentry->d_sb;
105    u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
106
107    buf->f_type = HFS_SUPER_MAGIC;
108    buf->f_bsize = sb->s_blocksize;
109    buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
110    buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
111    buf->f_bavail = buf->f_bfree;
112    buf->f_files = HFS_SB(sb)->fs_ablocks;
113    buf->f_ffree = HFS_SB(sb)->free_ablocks;
114    buf->f_fsid.val[0] = (u32)id;
115    buf->f_fsid.val[1] = (u32)(id >> 32);
116    buf->f_namelen = HFS_NAMELEN;
117
118    return 0;
119}
120
121static int hfs_remount(struct super_block *sb, int *flags, char *data)
122{
123    *flags |= MS_NODIRATIME;
124    if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
125        return 0;
126    if (!(*flags & MS_RDONLY)) {
127        if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
128            printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
129                   "running fsck.hfs is recommended. leaving read-only.\n");
130            sb->s_flags |= MS_RDONLY;
131            *flags |= MS_RDONLY;
132        } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
133            printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
134            sb->s_flags |= MS_RDONLY;
135            *flags |= MS_RDONLY;
136        }
137    }
138    return 0;
139}
140
141static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
142{
143    struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
144
145    if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
146        seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
147    if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
148        seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
149    seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
150    if (sbi->s_file_umask != 0133)
151        seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
152    if (sbi->s_dir_umask != 0022)
153        seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
154    if (sbi->part >= 0)
155        seq_printf(seq, ",part=%u", sbi->part);
156    if (sbi->session >= 0)
157        seq_printf(seq, ",session=%u", sbi->session);
158    if (sbi->nls_disk)
159        seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
160    if (sbi->nls_io)
161        seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
162    if (sbi->s_quiet)
163        seq_printf(seq, ",quiet");
164    return 0;
165}
166
167static struct inode *hfs_alloc_inode(struct super_block *sb)
168{
169    struct hfs_inode_info *i;
170
171    i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
172    return i ? &i->vfs_inode : NULL;
173}
174
175static void hfs_destroy_inode(struct inode *inode)
176{
177    kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
178}
179
180static const struct super_operations hfs_super_operations = {
181    .alloc_inode = hfs_alloc_inode,
182    .destroy_inode = hfs_destroy_inode,
183    .write_inode = hfs_write_inode,
184    .clear_inode = hfs_clear_inode,
185    .put_super = hfs_put_super,
186    .write_super = hfs_write_super,
187    .sync_fs = hfs_sync_fs,
188    .statfs = hfs_statfs,
189    .remount_fs = hfs_remount,
190    .show_options = hfs_show_options,
191};
192
193enum {
194    opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
195    opt_part, opt_session, opt_type, opt_creator, opt_quiet,
196    opt_codepage, opt_iocharset,
197    opt_err
198};
199
200static const match_table_t tokens = {
201    { opt_uid, "uid=%u" },
202    { opt_gid, "gid=%u" },
203    { opt_umask, "umask=%o" },
204    { opt_file_umask, "file_umask=%o" },
205    { opt_dir_umask, "dir_umask=%o" },
206    { opt_part, "part=%u" },
207    { opt_session, "session=%u" },
208    { opt_type, "type=%s" },
209    { opt_creator, "creator=%s" },
210    { opt_quiet, "quiet" },
211    { opt_codepage, "codepage=%s" },
212    { opt_iocharset, "iocharset=%s" },
213    { opt_err, NULL }
214};
215
216static inline int match_fourchar(substring_t *arg, u32 *result)
217{
218    if (arg->to - arg->from != 4)
219        return -EINVAL;
220    memcpy(result, arg->from, 4);
221    return 0;
222}
223
224/*
225 * parse_options()
226 *
227 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
228 * This function is called by hfs_read_super() to parse the mount options.
229 */
230static int parse_options(char *options, struct hfs_sb_info *hsb)
231{
232    char *p;
233    substring_t args[MAX_OPT_ARGS];
234    int tmp, token;
235
236    /* initialize the sb with defaults */
237    hsb->s_uid = current_uid();
238    hsb->s_gid = current_gid();
239    hsb->s_file_umask = 0133;
240    hsb->s_dir_umask = 0022;
241    hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
242    hsb->s_quiet = 0;
243    hsb->part = -1;
244    hsb->session = -1;
245
246    if (!options)
247        return 1;
248
249    while ((p = strsep(&options, ",")) != NULL) {
250        if (!*p)
251            continue;
252
253        token = match_token(p, tokens, args);
254        switch (token) {
255        case opt_uid:
256            if (match_int(&args[0], &tmp)) {
257                printk(KERN_ERR "hfs: uid requires an argument\n");
258                return 0;
259            }
260            hsb->s_uid = (uid_t)tmp;
261            break;
262        case opt_gid:
263            if (match_int(&args[0], &tmp)) {
264                printk(KERN_ERR "hfs: gid requires an argument\n");
265                return 0;
266            }
267            hsb->s_gid = (gid_t)tmp;
268            break;
269        case opt_umask:
270            if (match_octal(&args[0], &tmp)) {
271                printk(KERN_ERR "hfs: umask requires a value\n");
272                return 0;
273            }
274            hsb->s_file_umask = (umode_t)tmp;
275            hsb->s_dir_umask = (umode_t)tmp;
276            break;
277        case opt_file_umask:
278            if (match_octal(&args[0], &tmp)) {
279                printk(KERN_ERR "hfs: file_umask requires a value\n");
280                return 0;
281            }
282            hsb->s_file_umask = (umode_t)tmp;
283            break;
284        case opt_dir_umask:
285            if (match_octal(&args[0], &tmp)) {
286                printk(KERN_ERR "hfs: dir_umask requires a value\n");
287                return 0;
288            }
289            hsb->s_dir_umask = (umode_t)tmp;
290            break;
291        case opt_part:
292            if (match_int(&args[0], &hsb->part)) {
293                printk(KERN_ERR "hfs: part requires an argument\n");
294                return 0;
295            }
296            break;
297        case opt_session:
298            if (match_int(&args[0], &hsb->session)) {
299                printk(KERN_ERR "hfs: session requires an argument\n");
300                return 0;
301            }
302            break;
303        case opt_type:
304            if (match_fourchar(&args[0], &hsb->s_type)) {
305                printk(KERN_ERR "hfs: type requires a 4 character value\n");
306                return 0;
307            }
308            break;
309        case opt_creator:
310            if (match_fourchar(&args[0], &hsb->s_creator)) {
311                printk(KERN_ERR "hfs: creator requires a 4 character value\n");
312                return 0;
313            }
314            break;
315        case opt_quiet:
316            hsb->s_quiet = 1;
317            break;
318        case opt_codepage:
319            if (hsb->nls_disk) {
320                printk(KERN_ERR "hfs: unable to change codepage\n");
321                return 0;
322            }
323            p = match_strdup(&args[0]);
324            if (p)
325                hsb->nls_disk = load_nls(p);
326            if (!hsb->nls_disk) {
327                printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
328                kfree(p);
329                return 0;
330            }
331            kfree(p);
332            break;
333        case opt_iocharset:
334            if (hsb->nls_io) {
335                printk(KERN_ERR "hfs: unable to change iocharset\n");
336                return 0;
337            }
338            p = match_strdup(&args[0]);
339            if (p)
340                hsb->nls_io = load_nls(p);
341            if (!hsb->nls_io) {
342                printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
343                kfree(p);
344                return 0;
345            }
346            kfree(p);
347            break;
348        default:
349            return 0;
350        }
351    }
352
353    if (hsb->nls_disk && !hsb->nls_io) {
354        hsb->nls_io = load_nls_default();
355        if (!hsb->nls_io) {
356            printk(KERN_ERR "hfs: unable to load default iocharset\n");
357            return 0;
358        }
359    }
360    hsb->s_dir_umask &= 0777;
361    hsb->s_file_umask &= 0577;
362
363    return 1;
364}
365
366/*
367 * hfs_read_super()
368 *
369 * This is the function that is responsible for mounting an HFS
370 * filesystem. It performs all the tasks necessary to get enough data
371 * from the disk to read the root inode. This includes parsing the
372 * mount options, dealing with Macintosh partitions, reading the
373 * superblock and the allocation bitmap blocks, calling
374 * hfs_btree_init() to get the necessary data about the extents and
375 * catalog B-trees and, finally, reading the root inode into memory.
376 */
377static int hfs_fill_super(struct super_block *sb, void *data, int silent)
378{
379    struct hfs_sb_info *sbi;
380    struct hfs_find_data fd;
381    hfs_cat_rec rec;
382    struct inode *root_inode;
383    int res;
384
385    sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
386    if (!sbi)
387        return -ENOMEM;
388    sb->s_fs_info = sbi;
389    INIT_HLIST_HEAD(&sbi->rsrc_inodes);
390
391    res = -EINVAL;
392    if (!parse_options((char *)data, sbi)) {
393        printk(KERN_ERR "hfs: unable to parse mount options.\n");
394        goto bail;
395    }
396
397    sb->s_op = &hfs_super_operations;
398    sb->s_flags |= MS_NODIRATIME;
399    mutex_init(&sbi->bitmap_lock);
400
401    res = hfs_mdb_get(sb);
402    if (res) {
403        if (!silent)
404            printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
405                hfs_mdb_name(sb));
406        res = -EINVAL;
407        goto bail;
408    }
409
410    /* try to get the root inode */
411    hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
412    res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
413    if (!res) {
414        if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
415            res = -EIO;
416            goto bail;
417        }
418        hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
419    }
420    if (res) {
421        hfs_find_exit(&fd);
422        goto bail_no_root;
423    }
424    res = -EINVAL;
425    root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
426    hfs_find_exit(&fd);
427    if (!root_inode)
428        goto bail_no_root;
429
430    res = -ENOMEM;
431    sb->s_root = d_alloc_root(root_inode);
432    if (!sb->s_root)
433        goto bail_iput;
434
435    sb->s_root->d_op = &hfs_dentry_operations;
436
437    /* everything's okay */
438    return 0;
439
440bail_iput:
441    iput(root_inode);
442bail_no_root:
443    printk(KERN_ERR "hfs: get root inode failed.\n");
444bail:
445    hfs_mdb_put(sb);
446    return res;
447}
448
449static int hfs_get_sb(struct file_system_type *fs_type,
450              int flags, const char *dev_name, void *data,
451              struct vfsmount *mnt)
452{
453    return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
454}
455
456static struct file_system_type hfs_fs_type = {
457    .owner = THIS_MODULE,
458    .name = "hfs",
459    .get_sb = hfs_get_sb,
460    .kill_sb = kill_block_super,
461    .fs_flags = FS_REQUIRES_DEV,
462};
463
464static void hfs_init_once(void *p)
465{
466    struct hfs_inode_info *i = p;
467
468    inode_init_once(&i->vfs_inode);
469}
470
471static int __init init_hfs_fs(void)
472{
473    int err;
474
475    hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
476        sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
477        hfs_init_once);
478    if (!hfs_inode_cachep)
479        return -ENOMEM;
480    err = register_filesystem(&hfs_fs_type);
481    if (err)
482        kmem_cache_destroy(hfs_inode_cachep);
483    return err;
484}
485
486static void __exit exit_hfs_fs(void)
487{
488    unregister_filesystem(&hfs_fs_type);
489    kmem_cache_destroy(hfs_inode_cachep);
490}
491
492module_init(init_hfs_fs)
493module_exit(exit_hfs_fs)
494

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