->write_super lock_super pushdown
[linux-2.6/kvm.git] / fs / adfs / super.c
blob0ec5aaf47aa7757380b206feabf8d6eef39c03a1
1 /*
2 * linux/fs/adfs/super.c
4 * Copyright (C) 1997-1999 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/module.h>
11 #include <linux/errno.h>
12 #include <linux/fs.h>
13 #include <linux/adfs_fs.h>
14 #include <linux/slab.h>
15 #include <linux/time.h>
16 #include <linux/stat.h>
17 #include <linux/string.h>
18 #include <linux/init.h>
19 #include <linux/buffer_head.h>
20 #include <linux/vfs.h>
21 #include <linux/parser.h>
22 #include <linux/bitops.h>
23 #include <linux/mount.h>
24 #include <linux/seq_file.h>
26 #include <asm/uaccess.h>
27 #include <asm/system.h>
29 #include <stdarg.h>
31 #include "adfs.h"
32 #include "dir_f.h"
33 #include "dir_fplus.h"
35 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
36 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
38 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
40 char error_buf[128];
41 va_list args;
43 va_start(args, fmt);
44 vsnprintf(error_buf, sizeof(error_buf), fmt, args);
45 va_end(args);
47 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
48 sb->s_id, function ? ": " : "",
49 function ? function : "", error_buf);
52 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
54 int i;
56 /* sector size must be 256, 512 or 1024 bytes */
57 if (dr->log2secsize != 8 &&
58 dr->log2secsize != 9 &&
59 dr->log2secsize != 10)
60 return 1;
62 /* idlen must be at least log2secsize + 3 */
63 if (dr->idlen < dr->log2secsize + 3)
64 return 1;
66 /* we cannot have such a large disc that we
67 * are unable to represent sector offsets in
68 * 32 bits. This works out at 2.0 TB.
70 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
71 return 1;
73 /* idlen must be no greater than 19 v2 [1.0] */
74 if (dr->idlen > 19)
75 return 1;
77 /* reserved bytes should be zero */
78 for (i = 0; i < sizeof(dr->unused52); i++)
79 if (dr->unused52[i] != 0)
80 return 1;
82 return 0;
85 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
87 unsigned int v0, v1, v2, v3;
88 int i;
90 v0 = v1 = v2 = v3 = 0;
91 for (i = sb->s_blocksize - 4; i; i -= 4) {
92 v0 += map[i] + (v3 >> 8);
93 v3 &= 0xff;
94 v1 += map[i + 1] + (v0 >> 8);
95 v0 &= 0xff;
96 v2 += map[i + 2] + (v1 >> 8);
97 v1 &= 0xff;
98 v3 += map[i + 3] + (v2 >> 8);
99 v2 &= 0xff;
101 v0 += v3 >> 8;
102 v1 += map[1] + (v0 >> 8);
103 v2 += map[2] + (v1 >> 8);
104 v3 += map[3] + (v2 >> 8);
106 return v0 ^ v1 ^ v2 ^ v3;
109 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
111 unsigned char crosscheck = 0, zonecheck = 1;
112 int i;
114 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
115 unsigned char *map;
117 map = dm[i].dm_bh->b_data;
119 if (adfs_calczonecheck(sb, map) != map[0]) {
120 adfs_error(sb, "zone %d fails zonecheck", i);
121 zonecheck = 0;
123 crosscheck ^= map[3];
125 if (crosscheck != 0xff)
126 adfs_error(sb, "crosscheck != 0xff");
127 return crosscheck == 0xff && zonecheck;
130 static void adfs_put_super(struct super_block *sb)
132 int i;
133 struct adfs_sb_info *asb = ADFS_SB(sb);
135 lock_kernel();
137 for (i = 0; i < asb->s_map_size; i++)
138 brelse(asb->s_map[i].dm_bh);
139 kfree(asb->s_map);
140 kfree(asb);
141 sb->s_fs_info = NULL;
143 unlock_kernel();
146 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
148 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
150 if (asb->s_uid != 0)
151 seq_printf(seq, ",uid=%u", asb->s_uid);
152 if (asb->s_gid != 0)
153 seq_printf(seq, ",gid=%u", asb->s_gid);
154 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
155 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
156 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
157 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
159 return 0;
162 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
164 static const match_table_t tokens = {
165 {Opt_uid, "uid=%u"},
166 {Opt_gid, "gid=%u"},
167 {Opt_ownmask, "ownmask=%o"},
168 {Opt_othmask, "othmask=%o"},
169 {Opt_err, NULL}
172 static int parse_options(struct super_block *sb, char *options)
174 char *p;
175 struct adfs_sb_info *asb = ADFS_SB(sb);
176 int option;
178 if (!options)
179 return 0;
181 while ((p = strsep(&options, ",")) != NULL) {
182 substring_t args[MAX_OPT_ARGS];
183 int token;
184 if (!*p)
185 continue;
187 token = match_token(p, tokens, args);
188 switch (token) {
189 case Opt_uid:
190 if (match_int(args, &option))
191 return -EINVAL;
192 asb->s_uid = option;
193 break;
194 case Opt_gid:
195 if (match_int(args, &option))
196 return -EINVAL;
197 asb->s_gid = option;
198 break;
199 case Opt_ownmask:
200 if (match_octal(args, &option))
201 return -EINVAL;
202 asb->s_owner_mask = option;
203 break;
204 case Opt_othmask:
205 if (match_octal(args, &option))
206 return -EINVAL;
207 asb->s_other_mask = option;
208 break;
209 default:
210 printk("ADFS-fs: unrecognised mount option \"%s\" "
211 "or missing value\n", p);
212 return -EINVAL;
215 return 0;
218 static int adfs_remount(struct super_block *sb, int *flags, char *data)
220 *flags |= MS_NODIRATIME;
221 return parse_options(sb, data);
224 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
226 struct super_block *sb = dentry->d_sb;
227 struct adfs_sb_info *sbi = ADFS_SB(sb);
228 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
230 buf->f_type = ADFS_SUPER_MAGIC;
231 buf->f_namelen = sbi->s_namelen;
232 buf->f_bsize = sb->s_blocksize;
233 buf->f_blocks = sbi->s_size;
234 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size;
235 buf->f_bavail =
236 buf->f_bfree = adfs_map_free(sb);
237 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
238 buf->f_fsid.val[0] = (u32)id;
239 buf->f_fsid.val[1] = (u32)(id >> 32);
241 return 0;
244 static struct kmem_cache *adfs_inode_cachep;
246 static struct inode *adfs_alloc_inode(struct super_block *sb)
248 struct adfs_inode_info *ei;
249 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
250 if (!ei)
251 return NULL;
252 return &ei->vfs_inode;
255 static void adfs_destroy_inode(struct inode *inode)
257 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
260 static void init_once(void *foo)
262 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
264 inode_init_once(&ei->vfs_inode);
267 static int init_inodecache(void)
269 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
270 sizeof(struct adfs_inode_info),
271 0, (SLAB_RECLAIM_ACCOUNT|
272 SLAB_MEM_SPREAD),
273 init_once);
274 if (adfs_inode_cachep == NULL)
275 return -ENOMEM;
276 return 0;
279 static void destroy_inodecache(void)
281 kmem_cache_destroy(adfs_inode_cachep);
284 static const struct super_operations adfs_sops = {
285 .alloc_inode = adfs_alloc_inode,
286 .destroy_inode = adfs_destroy_inode,
287 .write_inode = adfs_write_inode,
288 .put_super = adfs_put_super,
289 .statfs = adfs_statfs,
290 .remount_fs = adfs_remount,
291 .show_options = adfs_show_options,
294 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
296 struct adfs_discmap *dm;
297 unsigned int map_addr, zone_size, nzones;
298 int i, zone;
299 struct adfs_sb_info *asb = ADFS_SB(sb);
301 nzones = asb->s_map_size;
302 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
303 map_addr = (nzones >> 1) * zone_size -
304 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
305 map_addr = signed_asl(map_addr, asb->s_map2blk);
307 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
309 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
310 if (dm == NULL) {
311 adfs_error(sb, "not enough memory");
312 return NULL;
315 for (zone = 0; zone < nzones; zone++, map_addr++) {
316 dm[zone].dm_startbit = 0;
317 dm[zone].dm_endbit = zone_size;
318 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
319 dm[zone].dm_bh = sb_bread(sb, map_addr);
321 if (!dm[zone].dm_bh) {
322 adfs_error(sb, "unable to read map");
323 goto error_free;
327 /* adjust the limits for the first and last map zones */
328 i = zone - 1;
329 dm[0].dm_startblk = 0;
330 dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
331 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
332 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
333 (ADFS_DR_SIZE_BITS - i * zone_size);
335 if (adfs_checkmap(sb, dm))
336 return dm;
338 adfs_error(sb, "map corrupted");
340 error_free:
341 while (--zone >= 0)
342 brelse(dm[zone].dm_bh);
344 kfree(dm);
345 return NULL;
348 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
350 unsigned long discsize;
352 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
353 discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
355 return discsize;
358 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
360 struct adfs_discrecord *dr;
361 struct buffer_head *bh;
362 struct object_info root_obj;
363 unsigned char *b_data;
364 struct adfs_sb_info *asb;
365 struct inode *root;
367 sb->s_flags |= MS_NODIRATIME;
369 asb = kzalloc(sizeof(*asb), GFP_KERNEL);
370 if (!asb)
371 return -ENOMEM;
372 sb->s_fs_info = asb;
374 /* set default options */
375 asb->s_uid = 0;
376 asb->s_gid = 0;
377 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
378 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
380 if (parse_options(sb, data))
381 goto error;
383 sb_set_blocksize(sb, BLOCK_SIZE);
384 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
385 adfs_error(sb, "unable to read superblock");
386 goto error;
389 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
391 if (adfs_checkbblk(b_data)) {
392 if (!silent)
393 printk("VFS: Can't find an adfs filesystem on dev "
394 "%s.\n", sb->s_id);
395 goto error_free_bh;
398 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
401 * Do some sanity checks on the ADFS disc record
403 if (adfs_checkdiscrecord(dr)) {
404 if (!silent)
405 printk("VPS: Can't find an adfs filesystem on dev "
406 "%s.\n", sb->s_id);
407 goto error_free_bh;
410 brelse(bh);
411 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
412 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
413 if (!bh) {
414 adfs_error(sb, "couldn't read superblock on "
415 "2nd try.");
416 goto error;
418 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
419 if (adfs_checkbblk(b_data)) {
420 adfs_error(sb, "disc record mismatch, very weird!");
421 goto error_free_bh;
423 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
424 } else {
425 if (!silent)
426 printk(KERN_ERR "VFS: Unsupported blocksize on dev "
427 "%s.\n", sb->s_id);
428 goto error;
432 * blocksize on this device should now be set to the ADFS log2secsize
435 sb->s_magic = ADFS_SUPER_MAGIC;
436 asb->s_idlen = dr->idlen;
437 asb->s_map_size = dr->nzones | (dr->nzones_high << 8);
438 asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
439 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits);
440 asb->s_version = dr->format_version;
441 asb->s_log2sharesize = dr->log2sharesize;
443 asb->s_map = adfs_read_map(sb, dr);
444 if (!asb->s_map)
445 goto error_free_bh;
447 brelse(bh);
450 * set up enough so that we can read an inode
452 sb->s_op = &adfs_sops;
454 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
456 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
457 root_obj.name_len = 0;
458 root_obj.loadaddr = 0;
459 root_obj.execaddr = 0;
460 root_obj.size = ADFS_NEWDIR_SIZE;
461 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
462 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
465 * If this is a F+ disk with variable length directories,
466 * get the root_size from the disc record.
468 if (asb->s_version) {
469 root_obj.size = le32_to_cpu(dr->root_size);
470 asb->s_dir = &adfs_fplus_dir_ops;
471 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
472 } else {
473 asb->s_dir = &adfs_f_dir_ops;
474 asb->s_namelen = ADFS_F_NAME_LEN;
477 root = adfs_iget(sb, &root_obj);
478 sb->s_root = d_alloc_root(root);
479 if (!sb->s_root) {
480 int i;
481 iput(root);
482 for (i = 0; i < asb->s_map_size; i++)
483 brelse(asb->s_map[i].dm_bh);
484 kfree(asb->s_map);
485 adfs_error(sb, "get root inode failed\n");
486 goto error;
487 } else
488 sb->s_root->d_op = &adfs_dentry_operations;
489 return 0;
491 error_free_bh:
492 brelse(bh);
493 error:
494 sb->s_fs_info = NULL;
495 kfree(asb);
496 return -EINVAL;
499 static int adfs_get_sb(struct file_system_type *fs_type,
500 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
502 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
503 mnt);
506 static struct file_system_type adfs_fs_type = {
507 .owner = THIS_MODULE,
508 .name = "adfs",
509 .get_sb = adfs_get_sb,
510 .kill_sb = kill_block_super,
511 .fs_flags = FS_REQUIRES_DEV,
514 static int __init init_adfs_fs(void)
516 int err = init_inodecache();
517 if (err)
518 goto out1;
519 err = register_filesystem(&adfs_fs_type);
520 if (err)
521 goto out;
522 return 0;
523 out:
524 destroy_inodecache();
525 out1:
526 return err;
529 static void __exit exit_adfs_fs(void)
531 unregister_filesystem(&adfs_fs_type);
532 destroy_inodecache();
535 module_init(init_adfs_fs)
536 module_exit(exit_adfs_fs)