Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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 
 13 #include "affs.h"
 14 
 15 extern struct inode_operations affs_symlink_inode_operations;
 16 extern struct timezone sys_tz;
 17 
 18 void
 19 affs_read_inode(struct inode *inode)
 20 {
 21         struct super_block      *sb = inode->i_sb;
 22         struct affs_sb_info     *sbi = AFFS_SB(sb);
 23         struct buffer_head      *bh;
 24         struct affs_head        *head;
 25         struct affs_tail        *tail;
 26         u32                      block;
 27         u32                      size;
 28         u32                      prot;
 29         u16                      id;
 30 
 31         pr_debug("AFFS: read_inode(%lu)\n",inode->i_ino);
 32 
 33         block = inode->i_ino;
 34         bh = affs_bread(sb, block);
 35         if (!bh) {
 36                 affs_warning(sb, "read_inode", "Cannot read block %d", block);
 37                 goto bad_inode;
 38         }
 39         if (affs_checksum_block(sb, bh) || be32_to_cpu(AFFS_HEAD(bh)->ptype) != T_SHORT) {
 40                 affs_warning(sb,"read_inode",
 41                            "Checksum or type (ptype=%d) error on inode %d",
 42                            AFFS_HEAD(bh)->ptype, block);
 43                 goto bad_inode;
 44         }
 45 
 46         head = AFFS_HEAD(bh);
 47         tail = AFFS_TAIL(sb, bh);
 48         prot = be32_to_cpu(tail->protect);
 49 
 50         inode->i_size = 0;
 51         inode->i_nlink = 1;
 52         inode->i_mode = 0;
 53         AFFS_I(inode)->i_extcnt = 1;
 54         AFFS_I(inode)->i_ext_last = ~1;
 55         AFFS_I(inode)->i_protect = prot;
 56         AFFS_I(inode)->i_opencnt = 0;
 57         AFFS_I(inode)->i_blkcnt = 0;
 58         AFFS_I(inode)->i_lc = NULL;
 59         AFFS_I(inode)->i_lc_size = 0;
 60         AFFS_I(inode)->i_lc_shift = 0;
 61         AFFS_I(inode)->i_lc_mask = 0;
 62         AFFS_I(inode)->i_ac = NULL;
 63         AFFS_I(inode)->i_ext_bh = NULL;
 64         AFFS_I(inode)->mmu_private = 0;
 65         AFFS_I(inode)->i_lastalloc = 0;
 66         AFFS_I(inode)->i_pa_cnt = 0;
 67 
 68         if (sbi->s_flags & SF_SETMODE)
 69                 inode->i_mode = sbi->s_mode;
 70         else
 71                 inode->i_mode = prot_to_mode(prot);
 72 
 73         id = be16_to_cpu(tail->uid);
 74         if (id == 0 || sbi->s_flags & SF_SETUID)
 75                 inode->i_uid = sbi->s_uid;
 76         else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
 77                 inode->i_uid = 0;
 78         else
 79                 inode->i_uid = id;
 80 
 81         id = be16_to_cpu(tail->gid);
 82         if (id == 0 || sbi->s_flags & SF_SETGID)
 83                 inode->i_gid = sbi->s_gid;
 84         else if (id == 0xFFFF && sbi->s_flags & SF_MUFS)
 85                 inode->i_gid = 0;
 86         else
 87                 inode->i_gid = id;
 88 
 89         switch (be32_to_cpu(tail->stype)) {
 90         case ST_ROOT:
 91                 inode->i_uid = sbi->s_uid;
 92                 inode->i_gid = sbi->s_gid;
 93                 /* fall through */
 94         case ST_USERDIR:
 95                 if (be32_to_cpu(tail->stype) == ST_USERDIR ||
 96                     sbi->s_flags & SF_SETMODE) {
 97                         if (inode->i_mode & S_IRUSR)
 98                                 inode->i_mode |= S_IXUSR;
 99                         if (inode->i_mode & S_IRGRP)
100                                 inode->i_mode |= S_IXGRP;
101                         if (inode->i_mode & S_IROTH)
102                                 inode->i_mode |= S_IXOTH;
103                         inode->i_mode |= S_IFDIR;
104                 } else
105                         inode->i_mode = S_IRUGO | S_IXUGO | S_IWUSR | S_IFDIR;
106                 if (tail->link_chain)
107                         inode->i_nlink = 2;
108                 /* Maybe it should be controlled by mount parameter? */
109                 //inode->i_mode |= S_ISVTX;
110                 inode->i_op = &affs_dir_inode_operations;
111                 inode->i_fop = &affs_dir_operations;
112                 break;
113         case ST_LINKDIR:
114 #if 0
115                 affs_warning(sb, "read_inode", "inode is LINKDIR");
116                 goto bad_inode;
117 #else
118                 inode->i_mode |= S_IFDIR;
119                 inode->i_op = NULL;
120                 inode->i_fop = NULL;
121                 break;
122 #endif
123         case ST_LINKFILE:
124                 affs_warning(sb, "read_inode", "inode is LINKFILE");
125                 goto bad_inode;
126         case ST_FILE:
127                 size = be32_to_cpu(tail->size);
128                 inode->i_mode |= S_IFREG;
129                 AFFS_I(inode)->mmu_private = inode->i_size = size;
130                 if (inode->i_size) {
131                         AFFS_I(inode)->i_blkcnt = (size - 1) /
132                                                sbi->s_data_blksize + 1;
133                         AFFS_I(inode)->i_extcnt = (AFFS_I(inode)->i_blkcnt - 1) /
134                                                sbi->s_hashsize + 1;
135                 }
136                 if (tail->link_chain)
137                         inode->i_nlink = 2;
138                 inode->i_mapping->a_ops = (sbi->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
139                 inode->i_op = &affs_file_inode_operations;
140                 inode->i_fop = &affs_file_operations;
141                 break;
142         case ST_SOFTLINK:
143                 inode->i_mode |= S_IFLNK;
144                 inode->i_op = &affs_symlink_inode_operations;
145                 inode->i_data.a_ops = &affs_symlink_aops;
146                 break;
147         }
148 
149         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec
150                        = (be32_to_cpu(tail->change.days) * (24 * 60 * 60) +
151                          be32_to_cpu(tail->change.mins) * 60 +
152                          be32_to_cpu(tail->change.ticks) / 50 +
153                          ((8 * 365 + 2) * 24 * 60 * 60)) +
154                          sys_tz.tz_minuteswest * 60;
155         inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_atime.tv_nsec = 0;
156         affs_brelse(bh);
157         return;
158 
159 bad_inode:
160         make_bad_inode(inode);
161         affs_brelse(bh);
162         return;
163 }
164 
165 int
166 affs_write_inode(struct inode *inode, int unused)
167 {
168         struct super_block      *sb = inode->i_sb;
169         struct buffer_head      *bh;
170         struct affs_tail        *tail;
171         uid_t                    uid;
172         gid_t                    gid;
173 
174         pr_debug("AFFS: write_inode(%lu)\n",inode->i_ino);
175 
176         if (!inode->i_nlink)
177                 // possibly free block
178                 return 0;
179         bh = affs_bread(sb, inode->i_ino);
180         if (!bh) {
181                 affs_error(sb,"write_inode","Cannot read block %lu",inode->i_ino);
182                 return -EIO;
183         }
184         tail = AFFS_TAIL(sb, bh);
185         if (tail->stype == cpu_to_be32(ST_ROOT)) {
186                 secs_to_datestamp(inode->i_mtime.tv_sec,&AFFS_ROOT_TAIL(sb, bh)->root_change);
187         } else {
188                 tail->protect = cpu_to_be32(AFFS_I(inode)->i_protect);
189                 tail->size = cpu_to_be32(inode->i_size);
190                 secs_to_datestamp(inode->i_mtime.tv_sec,&tail->change);
191                 if (!(inode->i_ino == AFFS_SB(sb)->s_root_block)) {
192                         uid = inode->i_uid;
193                         gid = inode->i_gid;
194                         if (AFFS_SB(sb)->s_flags & SF_MUFS) {
195                                 if (inode->i_uid == 0 || inode->i_uid == 0xFFFF)
196                                         uid = inode->i_uid ^ ~0;
197                                 if (inode->i_gid == 0 || inode->i_gid == 0xFFFF)
198                                         gid = inode->i_gid ^ ~0;
199                         }
200                         if (!(AFFS_SB(sb)->s_flags & SF_SETUID))
201                                 tail->uid = cpu_to_be16(uid);
202                         if (!(AFFS_SB(sb)->s_flags & SF_SETGID))
203                                 tail->gid = cpu_to_be16(gid);
204                 }
205         }
206         affs_fix_checksum(sb, bh);
207         mark_buffer_dirty_inode(bh, inode);
208         affs_brelse(bh);
209         affs_free_prealloc(inode);
210         return 0;
211 }
212 
213 int
214 affs_notify_change(struct dentry *dentry, struct iattr *attr)
215 {
216         struct inode *inode = dentry->d_inode;
217         int error;
218 
219         pr_debug("AFFS: notify_change(%lu,0x%x)\n",inode->i_ino,attr->ia_valid);
220 
221         error = inode_change_ok(inode,attr);
222         if (error)
223                 goto out;
224 
225         if (((attr->ia_valid & ATTR_UID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETUID)) ||
226             ((attr->ia_valid & ATTR_GID) && (AFFS_SB(inode->i_sb)->s_flags & SF_SETGID)) ||
227             ((attr->ia_valid & ATTR_MODE) &&
228              (AFFS_SB(inode->i_sb)->s_flags & (SF_SETMODE | SF_IMMUTABLE)))) {
229                 if (!(AFFS_SB(inode->i_sb)->s_flags & SF_QUIET))
230                         error = -EPERM;
231                 goto out;
232         }
233 
234         error = inode_setattr(inode, attr);
235         if (!error && (attr->ia_valid & ATTR_MODE))
236                 mode_to_prot(inode);
237 out:
238         return error;
239 }
240 
241 void
242 affs_put_inode(struct inode *inode)
243 {
244         pr_debug("AFFS: put_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
245         affs_free_prealloc(inode);
246         if (atomic_read(&inode->i_count) == 1) {
247                 down(&inode->i_sem);
248                 if (inode->i_size != AFFS_I(inode)->mmu_private)
249                         affs_truncate(inode);
250                 up(&inode->i_sem);
251         }
252 }
253 
254 void
255 affs_delete_inode(struct inode *inode)
256 {
257         pr_debug("AFFS: delete_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
258         inode->i_size = 0;
259         if (S_ISREG(inode->i_mode))
260                 affs_truncate(inode);
261         clear_inode(inode);
262         affs_free_block(inode->i_sb, inode->i_ino);
263 }
264 
265 void
266 affs_clear_inode(struct inode *inode)
267 {
268         unsigned long cache_page = (unsigned long) AFFS_I(inode)->i_lc;
269 
270         pr_debug("AFFS: clear_inode(ino=%lu, nlink=%u)\n", inode->i_ino, inode->i_nlink);
271         if (cache_page) {
272                 pr_debug("AFFS: freeing ext cache\n");
273                 AFFS_I(inode)->i_lc = NULL;
274                 AFFS_I(inode)->i_ac = NULL;
275                 free_page(cache_page);
276         }
277         affs_brelse(AFFS_I(inode)->i_ext_bh);
278         AFFS_I(inode)->i_ext_last = ~1;
279         AFFS_I(inode)->i_ext_bh = NULL;
280 }
281 
282 struct inode *
283 affs_new_inode(struct inode *dir)
284 {
285         struct super_block      *sb = dir->i_sb;
286         struct inode            *inode;
287         u32                      block;
288         struct buffer_head      *bh;
289 
290         if (!(inode = new_inode(sb)))
291                 goto err_inode;
292 
293         if (!(block = affs_alloc_block(dir, dir->i_ino)))
294                 goto err_block;
295 
296         bh = affs_getzeroblk(sb, block);
297         if (!bh)
298                 goto err_bh;
299         mark_buffer_dirty_inode(bh, inode);
300         affs_brelse(bh);
301 
302         inode->i_uid     = current->fsuid;
303         inode->i_gid     = current->fsgid;
304         inode->i_ino     = block;
305         inode->i_nlink   = 1;
306         inode->i_mtime   = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
307         AFFS_I(inode)->i_opencnt = 0;
308         AFFS_I(inode)->i_blkcnt = 0;
309         AFFS_I(inode)->i_lc = NULL;
310         AFFS_I(inode)->i_lc_size = 0;
311         AFFS_I(inode)->i_lc_shift = 0;
312         AFFS_I(inode)->i_lc_mask = 0;
313         AFFS_I(inode)->i_ac = NULL;
314         AFFS_I(inode)->i_ext_bh = NULL;
315         AFFS_I(inode)->mmu_private = 0;
316         AFFS_I(inode)->i_protect = 0;
317         AFFS_I(inode)->i_lastalloc = 0;
318         AFFS_I(inode)->i_pa_cnt = 0;
319         AFFS_I(inode)->i_extcnt = 1;
320         AFFS_I(inode)->i_ext_last = ~1;
321 
322         insert_inode_hash(inode);
323 
324         return inode;
325 
326 err_bh:
327         affs_free_block(sb, block);
328 err_block:
329         iput(inode);
330 err_inode:
331         return NULL;
332 }
333 
334 /*
335  * Add an entry to a directory. Create the header block
336  * and insert it into the hash table.
337  */
338 
339 int
340 affs_add_entry(struct inode *dir, struct inode *inode, struct dentry *dentry, s32 type)
341 {
342         struct super_block *sb = dir->i_sb;
343         struct buffer_head *inode_bh = NULL;
344         struct buffer_head *bh = NULL;
345         u32 block = 0;
346         int retval;
347 
348         pr_debug("AFFS: add_entry(dir=%u, inode=%u, \"%*s\", type=%d)\n", (u32)dir->i_ino,
349                  (u32)inode->i_ino, (int)dentry->d_name.len, dentry->d_name.name, type);
350 
351         retval = -EIO;
352         bh = affs_bread(sb, inode->i_ino);
353         if (!bh)
354                 goto done;
355 
356         affs_lock_link(inode);
357         switch (type) {
358         case ST_LINKFILE:
359         case ST_LINKDIR:
360                 inode_bh = bh;
361                 retval = -ENOSPC;
362                 block = affs_alloc_block(dir, dir->i_ino);
363                 if (!block)
364                         goto err;
365                 retval = -EIO;
366                 bh = affs_getzeroblk(sb, block);
367                 if (!bh)
368                         goto err;
369                 break;
370         default:
371                 break;
372         }
373 
374         AFFS_HEAD(bh)->ptype = cpu_to_be32(T_SHORT);
375         AFFS_HEAD(bh)->key = cpu_to_be32(bh->b_blocknr);
376         affs_copy_name(AFFS_TAIL(sb, bh)->name, dentry);
377         AFFS_TAIL(sb, bh)->stype = cpu_to_be32(type);
378         AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
379 
380         if (inode_bh) {
381                 __be32 chain;
382                 chain = AFFS_TAIL(sb, inode_bh)->link_chain;
383                 AFFS_TAIL(sb, bh)->original = cpu_to_be32(inode->i_ino);
384                 AFFS_TAIL(sb, bh)->link_chain = chain;
385                 AFFS_TAIL(sb, inode_bh)->link_chain = cpu_to_be32(block);
386                 affs_adjust_checksum(inode_bh, block - be32_to_cpu(chain));
387                 mark_buffer_dirty_inode(inode_bh, inode);
388                 inode->i_nlink = 2;
389                 atomic_inc(&inode->i_count);
390         }
391         affs_fix_checksum(sb, bh);
392         mark_buffer_dirty_inode(bh, inode);
393         dentry->d_fsdata = (void *)(long)bh->b_blocknr;
394 
395         affs_lock_dir(dir);
396         retval = affs_insert_hash(dir, bh);
397         mark_buffer_dirty_inode(bh, inode);
398         affs_unlock_dir(dir);
399         affs_unlock_link(inode);
400 
401         d_instantiate(dentry, inode);
402 done:
403         affs_brelse(inode_bh);
404         affs_brelse(bh);
405         return retval;
406 err:
407         if (block)
408                 affs_free_block(sb, block);
409         affs_unlock_link(inode);
410         goto done;
411 }
412 
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