Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze
[linux-3.10.git] / fs / jfs / inode.c
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19
20 #include <linux/fs.h>
21 #include <linux/mpage.h>
22 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/quotaops.h>
25 #include <linux/writeback.h>
26 #include "jfs_incore.h"
27 #include "jfs_inode.h"
28 #include "jfs_filsys.h"
29 #include "jfs_imap.h"
30 #include "jfs_extent.h"
31 #include "jfs_unicode.h"
32 #include "jfs_debug.h"
33
34
35 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
36 {
37         struct inode *inode;
38         int ret;
39
40         inode = iget_locked(sb, ino);
41         if (!inode)
42                 return ERR_PTR(-ENOMEM);
43         if (!(inode->i_state & I_NEW))
44                 return inode;
45
46         ret = diRead(inode);
47         if (ret < 0) {
48                 iget_failed(inode);
49                 return ERR_PTR(ret);
50         }
51
52         if (S_ISREG(inode->i_mode)) {
53                 inode->i_op = &jfs_file_inode_operations;
54                 inode->i_fop = &jfs_file_operations;
55                 inode->i_mapping->a_ops = &jfs_aops;
56         } else if (S_ISDIR(inode->i_mode)) {
57                 inode->i_op = &jfs_dir_inode_operations;
58                 inode->i_fop = &jfs_dir_operations;
59         } else if (S_ISLNK(inode->i_mode)) {
60                 if (inode->i_size >= IDATASIZE) {
61                         inode->i_op = &page_symlink_inode_operations;
62                         inode->i_mapping->a_ops = &jfs_aops;
63                 } else {
64                         inode->i_op = &jfs_fast_symlink_inode_operations;
65                         /*
66                          * The inline data should be null-terminated, but
67                          * don't let on-disk corruption crash the kernel
68                          */
69                         JFS_IP(inode)->i_inline[inode->i_size] = '\0';
70                 }
71         } else {
72                 inode->i_op = &jfs_file_inode_operations;
73                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
74         }
75         unlock_new_inode(inode);
76         return inode;
77 }
78
79 /*
80  * Workhorse of both fsync & write_inode
81  */
82 int jfs_commit_inode(struct inode *inode, int wait)
83 {
84         int rc = 0;
85         tid_t tid;
86         static int noisy = 5;
87
88         jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
89
90         /*
91          * Don't commit if inode has been committed since last being
92          * marked dirty, or if it has been deleted.
93          */
94         if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
95                 return 0;
96
97         if (isReadOnly(inode)) {
98                 /* kernel allows writes to devices on read-only
99                  * partitions and may think inode is dirty
100                  */
101                 if (!special_file(inode->i_mode) && noisy) {
102                         jfs_err("jfs_commit_inode(0x%p) called on "
103                                    "read-only volume", inode);
104                         jfs_err("Is remount racy?");
105                         noisy--;
106                 }
107                 return 0;
108         }
109
110         tid = txBegin(inode->i_sb, COMMIT_INODE);
111         mutex_lock(&JFS_IP(inode)->commit_mutex);
112
113         /*
114          * Retest inode state after taking commit_mutex
115          */
116         if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
117                 rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
118
119         txEnd(tid);
120         mutex_unlock(&JFS_IP(inode)->commit_mutex);
121         return rc;
122 }
123
124 int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
125 {
126         int wait = wbc->sync_mode == WB_SYNC_ALL;
127
128         if (test_cflag(COMMIT_Nolink, inode))
129                 return 0;
130         /*
131          * If COMMIT_DIRTY is not set, the inode isn't really dirty.
132          * It has been committed since the last change, but was still
133          * on the dirty inode list.
134          */
135          if (!test_cflag(COMMIT_Dirty, inode)) {
136                 /* Make sure committed changes hit the disk */
137                 jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
138                 return 0;
139          }
140
141         if (jfs_commit_inode(inode, wait)) {
142                 jfs_err("jfs_write_inode: jfs_commit_inode failed!");
143                 return -EIO;
144         } else
145                 return 0;
146 }
147
148 void jfs_evict_inode(struct inode *inode)
149 {
150         jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
151
152         if (!inode->i_nlink && !is_bad_inode(inode)) {
153                 dquot_initialize(inode);
154
155                 if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
156                         truncate_inode_pages(&inode->i_data, 0);
157
158                         if (test_cflag(COMMIT_Freewmap, inode))
159                                 jfs_free_zero_link(inode);
160
161                         diFree(inode);
162
163                         /*
164                          * Free the inode from the quota allocation.
165                          */
166                         dquot_initialize(inode);
167                         dquot_free_inode(inode);
168                 }
169         } else {
170                 truncate_inode_pages(&inode->i_data, 0);
171         }
172         end_writeback(inode);
173         dquot_drop(inode);
174 }
175
176 void jfs_dirty_inode(struct inode *inode, int flags)
177 {
178         static int noisy = 5;
179
180         if (isReadOnly(inode)) {
181                 if (!special_file(inode->i_mode) && noisy) {
182                         /* kernel allows writes to devices on read-only
183                          * partitions and may try to mark inode dirty
184                          */
185                         jfs_err("jfs_dirty_inode called on read-only volume");
186                         jfs_err("Is remount racy?");
187                         noisy--;
188                 }
189                 return;
190         }
191
192         set_cflag(COMMIT_Dirty, inode);
193 }
194
195 int jfs_get_block(struct inode *ip, sector_t lblock,
196                   struct buffer_head *bh_result, int create)
197 {
198         s64 lblock64 = lblock;
199         int rc = 0;
200         xad_t xad;
201         s64 xaddr;
202         int xflag;
203         s32 xlen = bh_result->b_size >> ip->i_blkbits;
204
205         /*
206          * Take appropriate lock on inode
207          */
208         if (create)
209                 IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
210         else
211                 IREAD_LOCK(ip, RDWRLOCK_NORMAL);
212
213         if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
214             (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
215             xaddr) {
216                 if (xflag & XAD_NOTRECORDED) {
217                         if (!create)
218                                 /*
219                                  * Allocated but not recorded, read treats
220                                  * this as a hole
221                                  */
222                                 goto unlock;
223 #ifdef _JFS_4K
224                         XADoffset(&xad, lblock64);
225                         XADlength(&xad, xlen);
226                         XADaddress(&xad, xaddr);
227 #else                           /* _JFS_4K */
228                         /*
229                          * As long as block size = 4K, this isn't a problem.
230                          * We should mark the whole page not ABNR, but how
231                          * will we know to mark the other blocks BH_New?
232                          */
233                         BUG();
234 #endif                          /* _JFS_4K */
235                         rc = extRecord(ip, &xad);
236                         if (rc)
237                                 goto unlock;
238                         set_buffer_new(bh_result);
239                 }
240
241                 map_bh(bh_result, ip->i_sb, xaddr);
242                 bh_result->b_size = xlen << ip->i_blkbits;
243                 goto unlock;
244         }
245         if (!create)
246                 goto unlock;
247
248         /*
249          * Allocate a new block
250          */
251 #ifdef _JFS_4K
252         if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
253                 goto unlock;
254         rc = extAlloc(ip, xlen, lblock64, &xad, false);
255         if (rc)
256                 goto unlock;
257
258         set_buffer_new(bh_result);
259         map_bh(bh_result, ip->i_sb, addressXAD(&xad));
260         bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
261
262 #else                           /* _JFS_4K */
263         /*
264          * We need to do whatever it takes to keep all but the last buffers
265          * in 4K pages - see jfs_write.c
266          */
267         BUG();
268 #endif                          /* _JFS_4K */
269
270       unlock:
271         /*
272          * Release lock on inode
273          */
274         if (create)
275                 IWRITE_UNLOCK(ip);
276         else
277                 IREAD_UNLOCK(ip);
278         return rc;
279 }
280
281 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
282 {
283         return block_write_full_page(page, jfs_get_block, wbc);
284 }
285
286 static int jfs_writepages(struct address_space *mapping,
287                         struct writeback_control *wbc)
288 {
289         return mpage_writepages(mapping, wbc, jfs_get_block);
290 }
291
292 static int jfs_readpage(struct file *file, struct page *page)
293 {
294         return mpage_readpage(page, jfs_get_block);
295 }
296
297 static int jfs_readpages(struct file *file, struct address_space *mapping,
298                 struct list_head *pages, unsigned nr_pages)
299 {
300         return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
301 }
302
303 static int jfs_write_begin(struct file *file, struct address_space *mapping,
304                                 loff_t pos, unsigned len, unsigned flags,
305                                 struct page **pagep, void **fsdata)
306 {
307         int ret;
308
309         ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
310                                 jfs_get_block);
311         if (unlikely(ret)) {
312                 loff_t isize = mapping->host->i_size;
313                 if (pos + len > isize)
314                         vmtruncate(mapping->host, isize);
315         }
316
317         return ret;
318 }
319
320 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
321 {
322         return generic_block_bmap(mapping, block, jfs_get_block);
323 }
324
325 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
326         const struct iovec *iov, loff_t offset, unsigned long nr_segs)
327 {
328         struct file *file = iocb->ki_filp;
329         struct inode *inode = file->f_mapping->host;
330         ssize_t ret;
331
332         ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
333                                  jfs_get_block);
334
335         /*
336          * In case of error extending write may have instantiated a few
337          * blocks outside i_size. Trim these off again.
338          */
339         if (unlikely((rw & WRITE) && ret < 0)) {
340                 loff_t isize = i_size_read(inode);
341                 loff_t end = offset + iov_length(iov, nr_segs);
342
343                 if (end > isize)
344                         vmtruncate(inode, isize);
345         }
346
347         return ret;
348 }
349
350 const struct address_space_operations jfs_aops = {
351         .readpage       = jfs_readpage,
352         .readpages      = jfs_readpages,
353         .writepage      = jfs_writepage,
354         .writepages     = jfs_writepages,
355         .write_begin    = jfs_write_begin,
356         .write_end      = nobh_write_end,
357         .bmap           = jfs_bmap,
358         .direct_IO      = jfs_direct_IO,
359 };
360
361 /*
362  * Guts of jfs_truncate.  Called with locks already held.  Can be called
363  * with directory for truncating directory index table.
364  */
365 void jfs_truncate_nolock(struct inode *ip, loff_t length)
366 {
367         loff_t newsize;
368         tid_t tid;
369
370         ASSERT(length >= 0);
371
372         if (test_cflag(COMMIT_Nolink, ip)) {
373                 xtTruncate(0, ip, length, COMMIT_WMAP);
374                 return;
375         }
376
377         do {
378                 tid = txBegin(ip->i_sb, 0);
379
380                 /*
381                  * The commit_mutex cannot be taken before txBegin.
382                  * txBegin may block and there is a chance the inode
383                  * could be marked dirty and need to be committed
384                  * before txBegin unblocks
385                  */
386                 mutex_lock(&JFS_IP(ip)->commit_mutex);
387
388                 newsize = xtTruncate(tid, ip, length,
389                                      COMMIT_TRUNCATE | COMMIT_PWMAP);
390                 if (newsize < 0) {
391                         txEnd(tid);
392                         mutex_unlock(&JFS_IP(ip)->commit_mutex);
393                         break;
394                 }
395
396                 ip->i_mtime = ip->i_ctime = CURRENT_TIME;
397                 mark_inode_dirty(ip);
398
399                 txCommit(tid, 1, &ip, 0);
400                 txEnd(tid);
401                 mutex_unlock(&JFS_IP(ip)->commit_mutex);
402         } while (newsize > length);     /* Truncate isn't always atomic */
403 }
404
405 void jfs_truncate(struct inode *ip)
406 {
407         jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
408
409         nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
410
411         IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
412         jfs_truncate_nolock(ip, ip->i_size);
413         IWRITE_UNLOCK(ip);
414 }