CRED: Wrap task credential accesses in the AFFS filesystem
[linux-2.6.git] / fs / affs / inode.c
1 /*
2  *  linux/fs/affs/inode.c
3  *
4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
5  *
6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
7  *
8  *  (C) 1992  Eric Youngdale Modified for ISO9660 filesystem.
9  *
10  *  (C) 1991  Linus Torvalds - minix filesystem
11  */
12 #include <linux/sched.h>
13 #include "affs.h"
14
15 extern const struct inode_operations affs_symlink_inode_operations;
16 extern struct timezone sys_tz;
17
18 struct inode *affs_iget(struct super_block *sb, unsigned long ino)
19 {
20         struct affs_sb_info     *sbi = AFFS_SB(sb);
21         struct buffer_head      *bh;
22         struct affs_head        *head;
23         struct affs_tail        *tail;
24         struct inode            *inode;
25         u32                      block;
26         u32                      size;
27         u32                      prot;
28         u16                      id;
29
30         inode = iget_locked(sb, ino);
31         if (!inode)
32                 return ERR_PTR(-ENOMEM);
33         if (!(inode->i_state & I_NEW))
34                 return inode;
35
36         pr_debug("AFFS: affs_iget(%lu)\n", inode->i_ino);
37
38         block = inode->i_ino;
39         bh = affs_bread(sb, block);
40         if (!bh) {
41                 affs_warning(sb, "read_inode", "Cannot read block %d", block);
42                 goto bad_inode;
43         }
44         if (affs_checksum_block(sb, bh) || be32_to_cpu(AFFS_HEAD(bh)->ptype) != T_SHORT) {
45                 affs_warning(sb,"read_inode",
46                            "Checksum or type (ptype=%d) error on inode %d",
47                            AFFS_HEAD(bh)->ptype, block);
48                 goto bad_inode;
49         }
50
51         head = AFFS_HEAD(bh);
52         tail = AFFS_TAIL(sb, bh);
53         prot = be32_to_cpu(tail->protect);
54
55         inode->i_size = 0;
56         inode->i_nlink = 1;
57         inode->i_mode = 0;
58         AFFS_I(inode)->i_extcnt = 1;
59         AFFS_I(inode)->i_ext_last = ~1;
60         AFFS_I(inode)->i_protect = prot;
61         atomic_set(&AFFS_I(inode)->i_opencnt, 0);
62         AFFS_I(inode)->i_blkcnt = 0;
63         AFFS_I(inode)->i_lc = NULL;
64         AFFS_I(inode)->i_lc_size = 0;
65         AFFS_I(inode)->i_lc_shift = 0;
66         AFFS_I(inode)->i_lc_mask = 0;
67         AFFS_I(inode)->i_ac = NULL;
68         AFFS_I(inode)->i_ext_bh = NULL;
69         AFFS_I(inode)->mmu_private = 0;
70         AFFS_I(inode)->i_lastalloc = 0;
71         AFFS_I(inode)->i_pa_cnt = 0;
72
73         if (sbi->s_flags & SF_SETMODE)
74                 inode->i_mode = sbi->s_mode;
75         else
76                 inode->i_mode = prot_to_mode(prot);
77
78         id = be16_to_cpu(tail->uid);
79         if (id == 0 || sbi->s_flags & SF_SETUID)
80                 inode->i_uid = sbi->s_uid;
81         else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
82                 inode->i_uid = 0;
83         else
84                 inode->i_uid = id;
85
86         id = be16_to_cpu(tail->gid);
87         if (id == 0 || sbi->s_flags & SF_SETGID)
88                 inode->i_gid = sbi->s_gid;
89         else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
90                 inode->i_gid = 0;
91         else
92                 inode->i_gid = id;
93
94         switch (be32_to_cpu(tail->stype)) {
95         case ST_ROOT:
96                 inode->i_uid = sbi->s_uid;
97                 inode->i_gid = sbi->s_gid;
98                 /* fall through */
99         case ST_USERDIR:
100                 if (be32_to_cpu(tail->stype) == ST_USERDIR ||
101                     sbi->s_flags & SF_SETMODE) {
102                         if (inode->i_mode & S_IRUSR)
103                                 inode->i_mode |= S_IXUSR;
104                         if (inode->i_mode & S_IRGRP)
105                                 inode->i_mode |= S_IXGRP;
106                         if (inode->i_mode & S_IROTH)
107                                 inode->i_mode |= S_IXOTH;
108                         inode->i_mode |= S_IFDIR;
109                 } else
110                         inode->i_mode = S_IRUGO | S_IXUGO | S_IWUSR | S_IFDIR;
111                 /* Maybe it should be controlled by mount parameter? */
112                 //inode->i_mode |= S_ISVTX;
113                 inode->i_op = &affs_dir_inode_operations;
114                 inode->i_fop = &affs_dir_operations;
115                 break;
116         case ST_LINKDIR:
117 #if 0
118                 affs_warning(sb, "read_inode", "inode is LINKDIR");
119                 goto bad_inode;
120 #else
121                 inode->i_mode |= S_IFDIR;
122                 inode->i_op = NULL;
123                 inode->i_fop = NULL;
124                 break;
125 #endif
126         case ST_LINKFILE:
127                 affs_warning(sb, "read_inode", "inode is LINKFILE");
128                 goto bad_inode;
129         case ST_FILE:
130                 size = be32_to_cpu(tail->size);
131                 inode->i_mode |= S_IFREG;
132                 AFFS_I(inode)->mmu_private = inode->i_size = size;
133                 if (inode->i_size) {
134                         AFFS_I(inode)->i_blkcnt = (size - 1) /
135                                                sbi->s_data_blksize + 1;
136                         AFFS_I(inode)->i_extcnt = (AFFS_I(inode)->i_blkcnt - 1) /
137                                                sbi->s_hashsize + 1;
138                 }
139                 if (tail->link_chain)
140                         inode->i_nlink = 2;
141                 inode->i_mapping->a_ops = (sbi->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
142                 inode->i_op = &affs_file_inode_operations;
143                 inode->i_fop = &affs_file_operations;
144                 break;
145         case ST_SOFTLINK:
146                 inode->i_mode |= S_IFLNK;
147                 inode->i_op = &affs_symlink_inode_operations;
148                 inode->i_data.a_ops = &affs_symlink_aops;
149                 break;
150         }
151
152         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec
153                        = (be32_to_cpu(tail->change.days) * (24 * 60 * 60) +
154                          be32_to_cpu(tail->change.mins) * 60 +
155                          be32_to_cpu(tail->change.ticks) / 50 +
156                          ((8 * 365 + 2) * 24 * 60 * 60)) +
157                          sys_tz.tz_minuteswest * 60;
158         inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_atime.tv_nsec = 0;
159         affs_brelse(bh);
160         unlock_new_inode(inode);
161         return inode;
162
163 bad_inode:
164         affs_brelse(bh);
165         iget_failed(inode);
166         return ERR_PTR(-EIO);
167 }
168
169 int
170 affs_write_inode(struct inode *inode, int unused)
171 {
172         struct super_block      *sb = inode->i_sb;
173         struct buffer_head      *bh;
174         struct affs_tail        *tail;
175         uid_t                    uid;
176         gid_t                    gid;
177
178         pr_debug("AFFS: write_inode(%lu)\n",inode->i_ino);
179
180         if (!inode->i_nlink)
181                 // possibly free block
182                 return 0;
183         bh = affs_bread(sb, inode->i_ino);
184         if (!bh) {
185                 affs_error(sb,"write_inode","Cannot read block %lu",inode->i_ino);
186                 return -EIO;
187         }
188         tail = AFFS_TAIL(sb, bh);
189         if (tail->stype == cpu_to_be32(ST_ROOT)) {
190                 secs_to_datestamp(inode->i_mtime.tv_sec,&AFFS_ROOT_TAIL(sb, bh)->root_change);
191         } else {
192                 tail->protect = cpu_to_be32(AFFS_I(inode)->i_protect);
193                 tail->size = cpu_to_be32(inode->i_size);
194                 secs_to_datestamp(inode->i_mtime.tv_sec,&tail->change);
195                 if (!(inode->i_ino == AFFS_SB(sb)->s_root_block)) {
196                         uid = inode->i_uid;
197                         gid = inode->i_gid;
198                         if (AFFS_SB(sb)->s_flags & SF_MUFS) {
199                                 if (inode->i_uid == 0 || inode->i_uid == 0xFFFF)
200                                         uid = inode->i_uid ^ ~0;
201                                 if (inode->i_gid == 0 || inode->i_gid == 0xFFFF)
202                                         gid = inode->i_gid ^ ~0;
203                         }
204                         if (!(AFFS_SB(sb)->s_flags & SF_SETUID))
205                                 tail->uid = cpu_to_be16(uid);
206                         if (!(AFFS_SB(sb)->s_flags & SF_SETGID))
207                                 tail->gid = cpu_to_be16(gid);
208                 }
209         }
210         affs_fix_checksum(sb, bh);
211         mark_buffer_dirty_inode(bh, inode);
212         affs_brelse(bh);
213         affs_free_prealloc(inode);
214         return 0;
215 }
216
217 int
218 affs_notify_change(struct dentry *dentry, struct iattr *attr)
219 {
220         struct inode *inode = dentry->d_inode;
221         int error;
222
223         pr_debug("AFFS: notify_change(%lu,0x%x)\n",inode->i_ino,attr->ia_valid);
224
225         error = inode_change_ok(inode,attr);
226         if (error)
227                 goto out;
228
229         if (((attr->ia_valid & ATTR_UID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETUID)) ||
230             ((attr->ia_valid & ATTR_GID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETGID)) ||
231             ((attr->ia_valid & ATTR_MODE) &&
232              (AFFS_SB(inode->i_sb)->s_flags & (SF_SETMODE | SF_IMMUTABLE)))) {
233                 if (!(AFFS_SB(inode->i_sb)->s_flags & SF_QUIET))
234                         error = -EPERM;
235                 goto out;
236         }
237
238         error = inode_setattr(inode, attr);
239         if (!error && (attr->ia_valid & ATTR_MODE))
240                 mode_to_prot(inode);
241 out:
242         return error;
243 }
244
245 void
246 affs_delete_inode(struct inode *inode)
247 {
248         pr_debug("AFFS: delete_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
249         truncate_inode_pages(&inode->i_data, 0);
250         inode->i_size = 0;
251         affs_truncate(inode);
252         clear_inode(inode);
253         affs_free_block(inode->i_sb, inode->i_ino);
254 }
255
256 void
257 affs_clear_inode(struct inode *inode)
258 {
259         unsigned long cache_page;
260
261         pr_debug("AFFS: clear_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
262
263         affs_free_prealloc(inode);
264         cache_page = (unsigned long)AFFS_I(inode)->i_lc;
265         if (cache_page) {
266                 pr_debug("AFFS: freeing ext cache\n");
267                 AFFS_I(inode)->i_lc = NULL;
268                 AFFS_I(inode)->i_ac = NULL;
269                 free_page(cache_page);
270         }
271         affs_brelse(AFFS_I(inode)->i_ext_bh);
272         AFFS_I(inode)->i_ext_last = ~1;
273         AFFS_I(inode)->i_ext_bh = NULL;
274 }
275
276 struct inode *
277 affs_new_inode(struct inode *dir)
278 {
279         struct super_block      *sb = dir->i_sb;
280         struct inode            *inode;
281         u32                      block;
282         struct buffer_head      *bh;
283
284         if (!(inode = new_inode(sb)))
285                 goto err_inode;
286
287         if (!(block = affs_alloc_block(dir, dir->i_ino)))
288                 goto err_block;
289
290         bh = affs_getzeroblk(sb, block);
291         if (!bh)
292                 goto err_bh;
293         mark_buffer_dirty_inode(bh, inode);
294         affs_brelse(bh);
295
296         inode->i_uid     = current_fsuid();
297         inode->i_gid     = current_fsgid();
298         inode->i_ino     = block;
299         inode->i_nlink   = 1;
300         inode->i_mtime   = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
301         atomic_set(&AFFS_I(inode)->i_opencnt, 0);
302         AFFS_I(inode)->i_blkcnt = 0;
303         AFFS_I(inode)->i_lc = NULL;
304         AFFS_I(inode)->i_lc_size = 0;
305         AFFS_I(inode)->i_lc_shift = 0;
306         AFFS_I(inode)->i_lc_mask = 0;
307         AFFS_I(inode)->i_ac = NULL;
308         AFFS_I(inode)->i_ext_bh = NULL;
309         AFFS_I(inode)->mmu_private = 0;
310         AFFS_I(inode)->i_protect = 0;
311         AFFS_I(inode)->i_lastalloc = 0;
312         AFFS_I(inode)->i_pa_cnt = 0;
313         AFFS_I(inode)->i_extcnt = 1;
314         AFFS_I(inode)->i_ext_last = ~1;
315
316         insert_inode_hash(inode);
317
318         return inode;
319
320 err_bh:
321         affs_free_block(sb, block);
322 err_block:
323         iput(inode);
324 err_inode:
325         return NULL;
326 }
327
328 /*
329  * Add an entry to a directory. Create the header block
330  * and insert it into the hash table.
331  */
332
333 int
334 affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type)
335 {
336         struct super_block *sb = dir->i_sb;
337         struct buffer_head *inode_bh = NULL;
338         struct buffer_head *bh = NULL;
339         u32 block = 0;
340         int retval;
341
342         pr_debug("AFFS: add_entry(dir=%u, inode=%u, \"%*s\", type=%d)\n", (u32)dir->i_ino,
343                  (u32)inode->i_ino, (int)dentry->d_name.len, dentry->d_name.name, type);
344
345         retval = -EIO;
346         bh = affs_bread(sb, inode->i_ino);
347         if (!bh)
348                 goto done;
349
350         affs_lock_link(inode);
351         switch (type) {
352         case ST_LINKFILE:
353         case ST_LINKDIR:
354                 retval = -ENOSPC;
355                 block = affs_alloc_block(dir, dir->i_ino);
356                 if (!block)
357                         goto err;
358                 retval = -EIO;
359                 inode_bh = bh;
360                 bh = affs_getzeroblk(sb, block);
361                 if (!bh)
362                         goto err;
363                 break;
364         default:
365                 break;
366         }
367
368         AFFS_HEAD(bh)->ptype = cpu_to_be32(T_SHORT);
369         AFFS_HEAD(bh)->key = cpu_to_be32(bh->b_blocknr);
370         affs_copy_name(AFFS_TAIL(sb, bh)->name, dentry);
371         AFFS_TAIL(sb, bh)->stype = cpu_to_be32(type);
372         AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
373
374         if (inode_bh) {
375                 __be32 chain;
376                 chain = AFFS_TAIL(sb, inode_bh)->link_chain;
377                 AFFS_TAIL(sb, bh)->original = cpu_to_be32(inode->i_ino);
378                 AFFS_TAIL(sb, bh)->link_chain = chain;
379                 AFFS_TAIL(sb, inode_bh)->link_chain = cpu_to_be32(block);
380                 affs_adjust_checksum(inode_bh, block - be32_to_cpu(chain));
381                 mark_buffer_dirty_inode(inode_bh, inode);
382                 inode->i_nlink = 2;
383                 atomic_inc(&inode->i_count);
384         }
385         affs_fix_checksum(sb, bh);
386         mark_buffer_dirty_inode(bh, inode);
387         dentry->d_fsdata = (void *)(long)bh->b_blocknr;
388
389         affs_lock_dir(dir);
390         retval = affs_insert_hash(dir, bh);
391         mark_buffer_dirty_inode(bh, inode);
392         affs_unlock_dir(dir);
393         affs_unlock_link(inode);
394
395         d_instantiate(dentry, inode);
396 done:
397         affs_brelse(inode_bh);
398         affs_brelse(bh);
399         return retval;
400 err:
401         if (block)
402                 affs_free_block(sb, block);
403         affs_unlock_link(inode);
404         goto done;
405 }