xref: /openbmc/linux/fs/ubifs/journal.c (revision 545e4006)
1 /*
2  * This file is part of UBIFS.
3  *
4  * Copyright (C) 2006-2008 Nokia Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published by
8  * the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program; if not, write to the Free Software Foundation, Inc., 51
17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18  *
19  * Authors: Artem Bityutskiy (Битюцкий Артём)
20  *          Adrian Hunter
21  */
22 
23 /*
24  * This file implements UBIFS journal.
25  *
26  * The journal consists of 2 parts - the log and bud LEBs. The log has fixed
27  * length and position, while a bud logical eraseblock is any LEB in the main
28  * area. Buds contain file system data - data nodes, inode nodes, etc. The log
29  * contains only references to buds and some other stuff like commit
30  * start node. The idea is that when we commit the journal, we do
31  * not copy the data, the buds just become indexed. Since after the commit the
32  * nodes in bud eraseblocks become leaf nodes of the file system index tree, we
33  * use term "bud". Analogy is obvious, bud eraseblocks contain nodes which will
34  * become leafs in the future.
35  *
36  * The journal is multi-headed because we want to write data to the journal as
37  * optimally as possible. It is nice to have nodes belonging to the same inode
38  * in one LEB, so we may write data owned by different inodes to different
39  * journal heads, although at present only one data head is used.
40  *
41  * For recovery reasons, the base head contains all inode nodes, all directory
42  * entry nodes and all truncate nodes. This means that the other heads contain
43  * only data nodes.
44  *
45  * Bud LEBs may be half-indexed. For example, if the bud was not full at the
46  * time of commit, the bud is retained to continue to be used in the journal,
47  * even though the "front" of the LEB is now indexed. In that case, the log
48  * reference contains the offset where the bud starts for the purposes of the
49  * journal.
50  *
51  * The journal size has to be limited, because the larger is the journal, the
52  * longer it takes to mount UBIFS (scanning the journal) and the more memory it
53  * takes (indexing in the TNC).
54  *
55  * All the journal write operations like 'ubifs_jnl_update()' here, which write
56  * multiple UBIFS nodes to the journal at one go, are atomic with respect to
57  * unclean reboots. Should the unclean reboot happen, the recovery code drops
58  * all the nodes.
59  */
60 
61 #include "ubifs.h"
62 
63 /**
64  * zero_ino_node_unused - zero out unused fields of an on-flash inode node.
65  * @ino: the inode to zero out
66  */
67 static inline void zero_ino_node_unused(struct ubifs_ino_node *ino)
68 {
69 	memset(ino->padding1, 0, 4);
70 	memset(ino->padding2, 0, 26);
71 }
72 
73 /**
74  * zero_dent_node_unused - zero out unused fields of an on-flash directory
75  *                         entry node.
76  * @dent: the directory entry to zero out
77  */
78 static inline void zero_dent_node_unused(struct ubifs_dent_node *dent)
79 {
80 	dent->padding1 = 0;
81 	memset(dent->padding2, 0, 4);
82 }
83 
84 /**
85  * zero_data_node_unused - zero out unused fields of an on-flash data node.
86  * @data: the data node to zero out
87  */
88 static inline void zero_data_node_unused(struct ubifs_data_node *data)
89 {
90 	memset(data->padding, 0, 2);
91 }
92 
93 /**
94  * zero_trun_node_unused - zero out unused fields of an on-flash truncation
95  *                         node.
96  * @trun: the truncation node to zero out
97  */
98 static inline void zero_trun_node_unused(struct ubifs_trun_node *trun)
99 {
100 	memset(trun->padding, 0, 12);
101 }
102 
103 /**
104  * reserve_space - reserve space in the journal.
105  * @c: UBIFS file-system description object
106  * @jhead: journal head number
107  * @len: node length
108  *
109  * This function reserves space in journal head @head. If the reservation
110  * succeeded, the journal head stays locked and later has to be unlocked using
111  * 'release_head()'. 'write_node()' and 'write_head()' functions also unlock
112  * it. Returns zero in case of success, %-EAGAIN if commit has to be done, and
113  * other negative error codes in case of other failures.
114  */
115 static int reserve_space(struct ubifs_info *c, int jhead, int len)
116 {
117 	int err = 0, err1, retries = 0, avail, lnum, offs, free, squeeze;
118 	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
119 
120 	/*
121 	 * Typically, the base head has smaller nodes written to it, so it is
122 	 * better to try to allocate space at the ends of eraseblocks. This is
123 	 * what the squeeze parameter does.
124 	 */
125 	squeeze = (jhead == BASEHD);
126 again:
127 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
128 
129 	if (c->ro_media) {
130 		err = -EROFS;
131 		goto out_unlock;
132 	}
133 
134 	avail = c->leb_size - wbuf->offs - wbuf->used;
135 	if (wbuf->lnum != -1 && avail >= len)
136 		return 0;
137 
138 	/*
139 	 * Write buffer wasn't seek'ed or there is no enough space - look for an
140 	 * LEB with some empty space.
141 	 */
142 	lnum = ubifs_find_free_space(c, len, &free, squeeze);
143 	if (lnum >= 0) {
144 		/* Found an LEB, add it to the journal head */
145 		offs = c->leb_size - free;
146 		err = ubifs_add_bud_to_log(c, jhead, lnum, offs);
147 		if (err)
148 			goto out_return;
149 		/* A new bud was successfully allocated and added to the log */
150 		goto out;
151 	}
152 
153 	err = lnum;
154 	if (err != -ENOSPC)
155 		goto out_unlock;
156 
157 	/*
158 	 * No free space, we have to run garbage collector to make
159 	 * some. But the write-buffer mutex has to be unlocked because
160 	 * GC also takes it.
161 	 */
162 	dbg_jnl("no free space  jhead %d, run GC", jhead);
163 	mutex_unlock(&wbuf->io_mutex);
164 
165 	lnum = ubifs_garbage_collect(c, 0);
166 	if (lnum < 0) {
167 		err = lnum;
168 		if (err != -ENOSPC)
169 			return err;
170 
171 		/*
172 		 * GC could not make a free LEB. But someone else may
173 		 * have allocated new bud for this journal head,
174 		 * because we dropped @wbuf->io_mutex, so try once
175 		 * again.
176 		 */
177 		dbg_jnl("GC couldn't make a free LEB for jhead %d", jhead);
178 		if (retries++ < 2) {
179 			dbg_jnl("retry (%d)", retries);
180 			goto again;
181 		}
182 
183 		dbg_jnl("return -ENOSPC");
184 		return err;
185 	}
186 
187 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
188 	dbg_jnl("got LEB %d for jhead %d", lnum, jhead);
189 	avail = c->leb_size - wbuf->offs - wbuf->used;
190 
191 	if (wbuf->lnum != -1 && avail >= len) {
192 		/*
193 		 * Someone else has switched the journal head and we have
194 		 * enough space now. This happens when more then one process is
195 		 * trying to write to the same journal head at the same time.
196 		 */
197 		dbg_jnl("return LEB %d back, already have LEB %d:%d",
198 			lnum, wbuf->lnum, wbuf->offs + wbuf->used);
199 		err = ubifs_return_leb(c, lnum);
200 		if (err)
201 			goto out_unlock;
202 		return 0;
203 	}
204 
205 	err = ubifs_add_bud_to_log(c, jhead, lnum, 0);
206 	if (err)
207 		goto out_return;
208 	offs = 0;
209 
210 out:
211 	err = ubifs_wbuf_seek_nolock(wbuf, lnum, offs, UBI_SHORTTERM);
212 	if (err)
213 		goto out_unlock;
214 
215 	return 0;
216 
217 out_unlock:
218 	mutex_unlock(&wbuf->io_mutex);
219 	return err;
220 
221 out_return:
222 	/* An error occurred and the LEB has to be returned to lprops */
223 	ubifs_assert(err < 0);
224 	err1 = ubifs_return_leb(c, lnum);
225 	if (err1 && err == -EAGAIN)
226 		/*
227 		 * Return original error code only if it is not %-EAGAIN,
228 		 * which is not really an error. Otherwise, return the error
229 		 * code of 'ubifs_return_leb()'.
230 		 */
231 		err = err1;
232 	mutex_unlock(&wbuf->io_mutex);
233 	return err;
234 }
235 
236 /**
237  * write_node - write node to a journal head.
238  * @c: UBIFS file-system description object
239  * @jhead: journal head
240  * @node: node to write
241  * @len: node length
242  * @lnum: LEB number written is returned here
243  * @offs: offset written is returned here
244  *
245  * This function writes a node to reserved space of journal head @jhead.
246  * Returns zero in case of success and a negative error code in case of
247  * failure.
248  */
249 static int write_node(struct ubifs_info *c, int jhead, void *node, int len,
250 		      int *lnum, int *offs)
251 {
252 	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
253 
254 	ubifs_assert(jhead != GCHD);
255 
256 	*lnum = c->jheads[jhead].wbuf.lnum;
257 	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
258 
259 	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
260 	ubifs_prepare_node(c, node, len, 0);
261 
262 	return ubifs_wbuf_write_nolock(wbuf, node, len);
263 }
264 
265 /**
266  * write_head - write data to a journal head.
267  * @c: UBIFS file-system description object
268  * @jhead: journal head
269  * @buf: buffer to write
270  * @len: length to write
271  * @lnum: LEB number written is returned here
272  * @offs: offset written is returned here
273  * @sync: non-zero if the write-buffer has to by synchronized
274  *
275  * This function is the same as 'write_node()' but it does not assume the
276  * buffer it is writing is a node, so it does not prepare it (which means
277  * initializing common header and calculating CRC).
278  */
279 static int write_head(struct ubifs_info *c, int jhead, void *buf, int len,
280 		      int *lnum, int *offs, int sync)
281 {
282 	int err;
283 	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
284 
285 	ubifs_assert(jhead != GCHD);
286 
287 	*lnum = c->jheads[jhead].wbuf.lnum;
288 	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
289 	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
290 
291 	err = ubifs_wbuf_write_nolock(wbuf, buf, len);
292 	if (err)
293 		return err;
294 	if (sync)
295 		err = ubifs_wbuf_sync_nolock(wbuf);
296 	return err;
297 }
298 
299 /**
300  * make_reservation - reserve journal space.
301  * @c: UBIFS file-system description object
302  * @jhead: journal head
303  * @len: how many bytes to reserve
304  *
305  * This function makes space reservation in journal head @jhead. The function
306  * takes the commit lock and locks the journal head, and the caller has to
307  * unlock the head and finish the reservation with 'finish_reservation()'.
308  * Returns zero in case of success and a negative error code in case of
309  * failure.
310  *
311  * Note, the journal head may be unlocked as soon as the data is written, while
312  * the commit lock has to be released after the data has been added to the
313  * TNC.
314  */
315 static int make_reservation(struct ubifs_info *c, int jhead, int len)
316 {
317 	int err, cmt_retries = 0, nospc_retries = 0;
318 
319 again:
320 	down_read(&c->commit_sem);
321 	err = reserve_space(c, jhead, len);
322 	if (!err)
323 		return 0;
324 	up_read(&c->commit_sem);
325 
326 	if (err == -ENOSPC) {
327 		/*
328 		 * GC could not make any progress. We should try to commit
329 		 * once because it could make some dirty space and GC would
330 		 * make progress, so make the error -EAGAIN so that the below
331 		 * will commit and re-try.
332 		 */
333 		if (nospc_retries++ < 2) {
334 			dbg_jnl("no space, retry");
335 			err = -EAGAIN;
336 		}
337 
338 		/*
339 		 * This means that the budgeting is incorrect. We always have
340 		 * to be able to write to the media, because all operations are
341 		 * budgeted. Deletions are not budgeted, though, but we reserve
342 		 * an extra LEB for them.
343 		 */
344 	}
345 
346 	if (err != -EAGAIN)
347 		goto out;
348 
349 	/*
350 	 * -EAGAIN means that the journal is full or too large, or the above
351 	 * code wants to do one commit. Do this and re-try.
352 	 */
353 	if (cmt_retries > 128) {
354 		/*
355 		 * This should not happen unless the journal size limitations
356 		 * are too tough.
357 		 */
358 		ubifs_err("stuck in space allocation");
359 		err = -ENOSPC;
360 		goto out;
361 	} else if (cmt_retries > 32)
362 		ubifs_warn("too many space allocation re-tries (%d)",
363 			   cmt_retries);
364 
365 	dbg_jnl("-EAGAIN, commit and retry (retried %d times)",
366 		cmt_retries);
367 	cmt_retries += 1;
368 
369 	err = ubifs_run_commit(c);
370 	if (err)
371 		return err;
372 	goto again;
373 
374 out:
375 	ubifs_err("cannot reserve %d bytes in jhead %d, error %d",
376 		  len, jhead, err);
377 	if (err == -ENOSPC) {
378 		/* This are some budgeting problems, print useful information */
379 		down_write(&c->commit_sem);
380 		spin_lock(&c->space_lock);
381 		dbg_dump_stack();
382 		dbg_dump_budg(c);
383 		spin_unlock(&c->space_lock);
384 		dbg_dump_lprops(c);
385 		cmt_retries = dbg_check_lprops(c);
386 		up_write(&c->commit_sem);
387 	}
388 	return err;
389 }
390 
391 /**
392  * release_head - release a journal head.
393  * @c: UBIFS file-system description object
394  * @jhead: journal head
395  *
396  * This function releases journal head @jhead which was locked by
397  * the 'make_reservation()' function. It has to be called after each successful
398  * 'make_reservation()' invocation.
399  */
400 static inline void release_head(struct ubifs_info *c, int jhead)
401 {
402 	mutex_unlock(&c->jheads[jhead].wbuf.io_mutex);
403 }
404 
405 /**
406  * finish_reservation - finish a reservation.
407  * @c: UBIFS file-system description object
408  *
409  * This function finishes journal space reservation. It must be called after
410  * 'make_reservation()'.
411  */
412 static void finish_reservation(struct ubifs_info *c)
413 {
414 	up_read(&c->commit_sem);
415 }
416 
417 /**
418  * get_dent_type - translate VFS inode mode to UBIFS directory entry type.
419  * @mode: inode mode
420  */
421 static int get_dent_type(int mode)
422 {
423 	switch (mode & S_IFMT) {
424 	case S_IFREG:
425 		return UBIFS_ITYPE_REG;
426 	case S_IFDIR:
427 		return UBIFS_ITYPE_DIR;
428 	case S_IFLNK:
429 		return UBIFS_ITYPE_LNK;
430 	case S_IFBLK:
431 		return UBIFS_ITYPE_BLK;
432 	case S_IFCHR:
433 		return UBIFS_ITYPE_CHR;
434 	case S_IFIFO:
435 		return UBIFS_ITYPE_FIFO;
436 	case S_IFSOCK:
437 		return UBIFS_ITYPE_SOCK;
438 	default:
439 		BUG();
440 	}
441 	return 0;
442 }
443 
444 /**
445  * pack_inode - pack an inode node.
446  * @c: UBIFS file-system description object
447  * @ino: buffer in which to pack inode node
448  * @inode: inode to pack
449  * @last: indicates the last node of the group
450  * @last_reference: non-zero if this is a deletion inode
451  */
452 static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino,
453 		       const struct inode *inode, int last,
454 		       int last_reference)
455 {
456 	int data_len = 0;
457 	struct ubifs_inode *ui = ubifs_inode(inode);
458 
459 	ino->ch.node_type = UBIFS_INO_NODE;
460 	ino_key_init_flash(c, &ino->key, inode->i_ino);
461 	ino->creat_sqnum = cpu_to_le64(ui->creat_sqnum);
462 	ino->atime_sec  = cpu_to_le64(inode->i_atime.tv_sec);
463 	ino->atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
464 	ino->ctime_sec  = cpu_to_le64(inode->i_ctime.tv_sec);
465 	ino->ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
466 	ino->mtime_sec  = cpu_to_le64(inode->i_mtime.tv_sec);
467 	ino->mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
468 	ino->uid   = cpu_to_le32(inode->i_uid);
469 	ino->gid   = cpu_to_le32(inode->i_gid);
470 	ino->mode  = cpu_to_le32(inode->i_mode);
471 	ino->flags = cpu_to_le32(ui->flags);
472 	ino->size  = cpu_to_le64(ui->ui_size);
473 	ino->nlink = cpu_to_le32(inode->i_nlink);
474 	ino->compr_type  = cpu_to_le16(ui->compr_type);
475 	ino->data_len    = cpu_to_le32(ui->data_len);
476 	ino->xattr_cnt   = cpu_to_le32(ui->xattr_cnt);
477 	ino->xattr_size  = cpu_to_le32(ui->xattr_size);
478 	ino->xattr_names = cpu_to_le32(ui->xattr_names);
479 	zero_ino_node_unused(ino);
480 
481 	/*
482 	 * Drop the attached data if this is a deletion inode, the data is not
483 	 * needed anymore.
484 	 */
485 	if (!last_reference) {
486 		memcpy(ino->data, ui->data, ui->data_len);
487 		data_len = ui->data_len;
488 	}
489 
490 	ubifs_prep_grp_node(c, ino, UBIFS_INO_NODE_SZ + data_len, last);
491 }
492 
493 /**
494  * mark_inode_clean - mark UBIFS inode as clean.
495  * @c: UBIFS file-system description object
496  * @ui: UBIFS inode to mark as clean
497  *
498  * This helper function marks UBIFS inode @ui as clean by cleaning the
499  * @ui->dirty flag and releasing its budget. Note, VFS may still treat the
500  * inode as dirty and try to write it back, but 'ubifs_write_inode()' would
501  * just do nothing.
502  */
503 static void mark_inode_clean(struct ubifs_info *c, struct ubifs_inode *ui)
504 {
505 	if (ui->dirty)
506 		ubifs_release_dirty_inode_budget(c, ui);
507 	ui->dirty = 0;
508 }
509 
510 /**
511  * ubifs_jnl_update - update inode.
512  * @c: UBIFS file-system description object
513  * @dir: parent inode or host inode in case of extended attributes
514  * @nm: directory entry name
515  * @inode: inode to update
516  * @deletion: indicates a directory entry deletion i.e unlink or rmdir
517  * @xent: non-zero if the directory entry is an extended attribute entry
518  *
519  * This function updates an inode by writing a directory entry (or extended
520  * attribute entry), the inode itself, and the parent directory inode (or the
521  * host inode) to the journal.
522  *
523  * The function writes the host inode @dir last, which is important in case of
524  * extended attributes. Indeed, then we guarantee that if the host inode gets
525  * synchronized (with 'fsync()'), and the write-buffer it sits in gets flushed,
526  * the extended attribute inode gets flushed too. And this is exactly what the
527  * user expects - synchronizing the host inode synchronizes its extended
528  * attributes. Similarly, this guarantees that if @dir is synchronized, its
529  * directory entry corresponding to @nm gets synchronized too.
530  *
531  * If the inode (@inode) or the parent directory (@dir) are synchronous, this
532  * function synchronizes the write-buffer.
533  *
534  * This function marks the @dir and @inode inodes as clean and returns zero on
535  * success. In case of failure, a negative error code is returned.
536  */
537 int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
538 		     const struct qstr *nm, const struct inode *inode,
539 		     int deletion, int xent)
540 {
541 	int err, dlen, ilen, len, lnum, ino_offs, dent_offs;
542 	int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir);
543 	int last_reference = !!(deletion && inode->i_nlink == 0);
544 	struct ubifs_inode *ui = ubifs_inode(inode);
545 	struct ubifs_inode *dir_ui = ubifs_inode(dir);
546 	struct ubifs_dent_node *dent;
547 	struct ubifs_ino_node *ino;
548 	union ubifs_key dent_key, ino_key;
549 
550 	dbg_jnl("ino %lu, dent '%.*s', data len %d in dir ino %lu",
551 		inode->i_ino, nm->len, nm->name, ui->data_len, dir->i_ino);
552 	ubifs_assert(dir_ui->data_len == 0);
553 	ubifs_assert(mutex_is_locked(&dir_ui->ui_mutex));
554 
555 	dlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
556 	ilen = UBIFS_INO_NODE_SZ;
557 
558 	/*
559 	 * If the last reference to the inode is being deleted, then there is
560 	 * no need to attach and write inode data, it is being deleted anyway.
561 	 * And if the inode is being deleted, no need to synchronize
562 	 * write-buffer even if the inode is synchronous.
563 	 */
564 	if (!last_reference) {
565 		ilen += ui->data_len;
566 		sync |= IS_SYNC(inode);
567 	}
568 
569 	aligned_dlen = ALIGN(dlen, 8);
570 	aligned_ilen = ALIGN(ilen, 8);
571 	len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ;
572 	dent = kmalloc(len, GFP_NOFS);
573 	if (!dent)
574 		return -ENOMEM;
575 
576 	/* Make reservation before allocating sequence numbers */
577 	err = make_reservation(c, BASEHD, len);
578 	if (err)
579 		goto out_free;
580 
581 	if (!xent) {
582 		dent->ch.node_type = UBIFS_DENT_NODE;
583 		dent_key_init(c, &dent_key, dir->i_ino, nm);
584 	} else {
585 		dent->ch.node_type = UBIFS_XENT_NODE;
586 		xent_key_init(c, &dent_key, dir->i_ino, nm);
587 	}
588 
589 	key_write(c, &dent_key, dent->key);
590 	dent->inum = deletion ? 0 : cpu_to_le64(inode->i_ino);
591 	dent->type = get_dent_type(inode->i_mode);
592 	dent->nlen = cpu_to_le16(nm->len);
593 	memcpy(dent->name, nm->name, nm->len);
594 	dent->name[nm->len] = '\0';
595 	zero_dent_node_unused(dent);
596 	ubifs_prep_grp_node(c, dent, dlen, 0);
597 
598 	ino = (void *)dent + aligned_dlen;
599 	pack_inode(c, ino, inode, 0, last_reference);
600 	ino = (void *)ino + aligned_ilen;
601 	pack_inode(c, ino, dir, 1, 0);
602 
603 	if (last_reference) {
604 		err = ubifs_add_orphan(c, inode->i_ino);
605 		if (err) {
606 			release_head(c, BASEHD);
607 			goto out_finish;
608 		}
609 	}
610 
611 	err = write_head(c, BASEHD, dent, len, &lnum, &dent_offs, sync);
612 	if (err)
613 		goto out_release;
614 	if (!sync) {
615 		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
616 
617 		ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
618 		ubifs_wbuf_add_ino_nolock(wbuf, dir->i_ino);
619 	}
620 	release_head(c, BASEHD);
621 	kfree(dent);
622 
623 	if (deletion) {
624 		err = ubifs_tnc_remove_nm(c, &dent_key, nm);
625 		if (err)
626 			goto out_ro;
627 		err = ubifs_add_dirt(c, lnum, dlen);
628 	} else
629 		err = ubifs_tnc_add_nm(c, &dent_key, lnum, dent_offs, dlen, nm);
630 	if (err)
631 		goto out_ro;
632 
633 	/*
634 	 * Note, we do not remove the inode from TNC even if the last reference
635 	 * to it has just been deleted, because the inode may still be opened.
636 	 * Instead, the inode has been added to orphan lists and the orphan
637 	 * subsystem will take further care about it.
638 	 */
639 	ino_key_init(c, &ino_key, inode->i_ino);
640 	ino_offs = dent_offs + aligned_dlen;
641 	err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, ilen);
642 	if (err)
643 		goto out_ro;
644 
645 	ino_key_init(c, &ino_key, dir->i_ino);
646 	ino_offs += aligned_ilen;
647 	err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, UBIFS_INO_NODE_SZ);
648 	if (err)
649 		goto out_ro;
650 
651 	finish_reservation(c);
652 	spin_lock(&ui->ui_lock);
653 	ui->synced_i_size = ui->ui_size;
654 	spin_unlock(&ui->ui_lock);
655 	mark_inode_clean(c, ui);
656 	mark_inode_clean(c, dir_ui);
657 	return 0;
658 
659 out_finish:
660 	finish_reservation(c);
661 out_free:
662 	kfree(dent);
663 	return err;
664 
665 out_release:
666 	release_head(c, BASEHD);
667 out_ro:
668 	ubifs_ro_mode(c, err);
669 	if (last_reference)
670 		ubifs_delete_orphan(c, inode->i_ino);
671 	finish_reservation(c);
672 	return err;
673 }
674 
675 /**
676  * ubifs_jnl_write_data - write a data node to the journal.
677  * @c: UBIFS file-system description object
678  * @inode: inode the data node belongs to
679  * @key: node key
680  * @buf: buffer to write
681  * @len: data length (must not exceed %UBIFS_BLOCK_SIZE)
682  *
683  * This function writes a data node to the journal. Returns %0 if the data node
684  * was successfully written, and a negative error code in case of failure.
685  */
686 int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
687 			 const union ubifs_key *key, const void *buf, int len)
688 {
689 	struct ubifs_data_node *data;
690 	int err, lnum, offs, compr_type, out_len;
691 	int dlen = UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR;
692 	struct ubifs_inode *ui = ubifs_inode(inode);
693 
694 	dbg_jnl("ino %lu, blk %u, len %d, key %s", key_inum(c, key),
695 		key_block(c, key), len, DBGKEY(key));
696 	ubifs_assert(len <= UBIFS_BLOCK_SIZE);
697 
698 	data = kmalloc(dlen, GFP_NOFS);
699 	if (!data)
700 		return -ENOMEM;
701 
702 	data->ch.node_type = UBIFS_DATA_NODE;
703 	key_write(c, key, &data->key);
704 	data->size = cpu_to_le32(len);
705 	zero_data_node_unused(data);
706 
707 	if (!(ui->flags && UBIFS_COMPR_FL))
708 		/* Compression is disabled for this inode */
709 		compr_type = UBIFS_COMPR_NONE;
710 	else
711 		compr_type = ui->compr_type;
712 
713 	out_len = dlen - UBIFS_DATA_NODE_SZ;
714 	ubifs_compress(buf, len, &data->data, &out_len, &compr_type);
715 	ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
716 
717 	dlen = UBIFS_DATA_NODE_SZ + out_len;
718 	data->compr_type = cpu_to_le16(compr_type);
719 
720 	/* Make reservation before allocating sequence numbers */
721 	err = make_reservation(c, DATAHD, dlen);
722 	if (err)
723 		goto out_free;
724 
725 	err = write_node(c, DATAHD, data, dlen, &lnum, &offs);
726 	if (err)
727 		goto out_release;
728 	ubifs_wbuf_add_ino_nolock(&c->jheads[DATAHD].wbuf, key_inum(c, key));
729 	release_head(c, DATAHD);
730 
731 	err = ubifs_tnc_add(c, key, lnum, offs, dlen);
732 	if (err)
733 		goto out_ro;
734 
735 	finish_reservation(c);
736 	kfree(data);
737 	return 0;
738 
739 out_release:
740 	release_head(c, DATAHD);
741 out_ro:
742 	ubifs_ro_mode(c, err);
743 	finish_reservation(c);
744 out_free:
745 	kfree(data);
746 	return err;
747 }
748 
749 /**
750  * ubifs_jnl_write_inode - flush inode to the journal.
751  * @c: UBIFS file-system description object
752  * @inode: inode to flush
753  * @deletion: inode has been deleted
754  *
755  * This function writes inode @inode to the journal. If the inode is
756  * synchronous, it also synchronizes the write-buffer. Returns zero in case of
757  * success and a negative error code in case of failure.
758  */
759 int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode,
760 			  int deletion)
761 {
762 	int err, len, lnum, offs, sync = 0;
763 	struct ubifs_ino_node *ino;
764 	struct ubifs_inode *ui = ubifs_inode(inode);
765 
766 	dbg_jnl("ino %lu%s", inode->i_ino,
767 		deletion ? " (last reference)" : "");
768 	if (deletion)
769 		ubifs_assert(inode->i_nlink == 0);
770 
771 	len = UBIFS_INO_NODE_SZ;
772 	/*
773 	 * If the inode is being deleted, do not write the attached data. No
774 	 * need to synchronize the write-buffer either.
775 	 */
776 	if (!deletion) {
777 		len += ui->data_len;
778 		sync = IS_SYNC(inode);
779 	}
780 	ino = kmalloc(len, GFP_NOFS);
781 	if (!ino)
782 		return -ENOMEM;
783 
784 	/* Make reservation before allocating sequence numbers */
785 	err = make_reservation(c, BASEHD, len);
786 	if (err)
787 		goto out_free;
788 
789 	pack_inode(c, ino, inode, 1, deletion);
790 	err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
791 	if (err)
792 		goto out_release;
793 	if (!sync)
794 		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
795 					  inode->i_ino);
796 	release_head(c, BASEHD);
797 
798 	if (deletion) {
799 		err = ubifs_tnc_remove_ino(c, inode->i_ino);
800 		if (err)
801 			goto out_ro;
802 		ubifs_delete_orphan(c, inode->i_ino);
803 		err = ubifs_add_dirt(c, lnum, len);
804 	} else {
805 		union ubifs_key key;
806 
807 		ino_key_init(c, &key, inode->i_ino);
808 		err = ubifs_tnc_add(c, &key, lnum, offs, len);
809 	}
810 	if (err)
811 		goto out_ro;
812 
813 	finish_reservation(c);
814 	spin_lock(&ui->ui_lock);
815 	ui->synced_i_size = ui->ui_size;
816 	spin_unlock(&ui->ui_lock);
817 	kfree(ino);
818 	return 0;
819 
820 out_release:
821 	release_head(c, BASEHD);
822 out_ro:
823 	ubifs_ro_mode(c, err);
824 	finish_reservation(c);
825 out_free:
826 	kfree(ino);
827 	return err;
828 }
829 
830 /**
831  * ubifs_jnl_rename - rename a directory entry.
832  * @c: UBIFS file-system description object
833  * @old_dir: parent inode of directory entry to rename
834  * @old_dentry: directory entry to rename
835  * @new_dir: parent inode of directory entry to rename
836  * @new_dentry: new directory entry (or directory entry to replace)
837  * @sync: non-zero if the write-buffer has to be synchronized
838  *
839  * This function implements the re-name operation which may involve writing up
840  * to 3 inodes and 2 directory entries. It marks the written inodes as clean
841  * and returns zero on success. In case of failure, a negative error code is
842  * returned.
843  */
844 int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
845 		     const struct dentry *old_dentry,
846 		     const struct inode *new_dir,
847 		     const struct dentry *new_dentry, int sync)
848 {
849 	void *p;
850 	union ubifs_key key;
851 	struct ubifs_dent_node *dent, *dent2;
852 	int err, dlen1, dlen2, ilen, lnum, offs, len;
853 	const struct inode *old_inode = old_dentry->d_inode;
854 	const struct inode *new_inode = new_dentry->d_inode;
855 	int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ;
856 	int last_reference = !!(new_inode && new_inode->i_nlink == 0);
857 	int move = (old_dir != new_dir);
858 	struct ubifs_inode *uninitialized_var(new_ui);
859 
860 	dbg_jnl("dent '%.*s' in dir ino %lu to dent '%.*s' in dir ino %lu",
861 		old_dentry->d_name.len, old_dentry->d_name.name,
862 		old_dir->i_ino, new_dentry->d_name.len,
863 		new_dentry->d_name.name, new_dir->i_ino);
864 	ubifs_assert(ubifs_inode(old_dir)->data_len == 0);
865 	ubifs_assert(ubifs_inode(new_dir)->data_len == 0);
866 	ubifs_assert(mutex_is_locked(&ubifs_inode(old_dir)->ui_mutex));
867 	ubifs_assert(mutex_is_locked(&ubifs_inode(new_dir)->ui_mutex));
868 
869 	dlen1 = UBIFS_DENT_NODE_SZ + new_dentry->d_name.len + 1;
870 	dlen2 = UBIFS_DENT_NODE_SZ + old_dentry->d_name.len + 1;
871 	if (new_inode) {
872 		new_ui = ubifs_inode(new_inode);
873 		ubifs_assert(mutex_is_locked(&new_ui->ui_mutex));
874 		ilen = UBIFS_INO_NODE_SZ;
875 		if (!last_reference)
876 			ilen += new_ui->data_len;
877 	} else
878 		ilen = 0;
879 
880 	aligned_dlen1 = ALIGN(dlen1, 8);
881 	aligned_dlen2 = ALIGN(dlen2, 8);
882 	len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8);
883 	if (old_dir != new_dir)
884 		len += plen;
885 	dent = kmalloc(len, GFP_NOFS);
886 	if (!dent)
887 		return -ENOMEM;
888 
889 	/* Make reservation before allocating sequence numbers */
890 	err = make_reservation(c, BASEHD, len);
891 	if (err)
892 		goto out_free;
893 
894 	/* Make new dent */
895 	dent->ch.node_type = UBIFS_DENT_NODE;
896 	dent_key_init_flash(c, &dent->key, new_dir->i_ino, &new_dentry->d_name);
897 	dent->inum = cpu_to_le64(old_inode->i_ino);
898 	dent->type = get_dent_type(old_inode->i_mode);
899 	dent->nlen = cpu_to_le16(new_dentry->d_name.len);
900 	memcpy(dent->name, new_dentry->d_name.name, new_dentry->d_name.len);
901 	dent->name[new_dentry->d_name.len] = '\0';
902 	zero_dent_node_unused(dent);
903 	ubifs_prep_grp_node(c, dent, dlen1, 0);
904 
905 	/* Make deletion dent */
906 	dent2 = (void *)dent + aligned_dlen1;
907 	dent2->ch.node_type = UBIFS_DENT_NODE;
908 	dent_key_init_flash(c, &dent2->key, old_dir->i_ino,
909 			    &old_dentry->d_name);
910 	dent2->inum = 0;
911 	dent2->type = DT_UNKNOWN;
912 	dent2->nlen = cpu_to_le16(old_dentry->d_name.len);
913 	memcpy(dent2->name, old_dentry->d_name.name, old_dentry->d_name.len);
914 	dent2->name[old_dentry->d_name.len] = '\0';
915 	zero_dent_node_unused(dent2);
916 	ubifs_prep_grp_node(c, dent2, dlen2, 0);
917 
918 	p = (void *)dent2 + aligned_dlen2;
919 	if (new_inode) {
920 		pack_inode(c, p, new_inode, 0, last_reference);
921 		p += ALIGN(ilen, 8);
922 	}
923 
924 	if (!move)
925 		pack_inode(c, p, old_dir, 1, 0);
926 	else {
927 		pack_inode(c, p, old_dir, 0, 0);
928 		p += ALIGN(plen, 8);
929 		pack_inode(c, p, new_dir, 1, 0);
930 	}
931 
932 	if (last_reference) {
933 		err = ubifs_add_orphan(c, new_inode->i_ino);
934 		if (err) {
935 			release_head(c, BASEHD);
936 			goto out_finish;
937 		}
938 	}
939 
940 	err = write_head(c, BASEHD, dent, len, &lnum, &offs, sync);
941 	if (err)
942 		goto out_release;
943 	if (!sync) {
944 		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
945 
946 		ubifs_wbuf_add_ino_nolock(wbuf, new_dir->i_ino);
947 		ubifs_wbuf_add_ino_nolock(wbuf, old_dir->i_ino);
948 		if (new_inode)
949 			ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
950 						  new_inode->i_ino);
951 	}
952 	release_head(c, BASEHD);
953 
954 	dent_key_init(c, &key, new_dir->i_ino, &new_dentry->d_name);
955 	err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &new_dentry->d_name);
956 	if (err)
957 		goto out_ro;
958 
959 	err = ubifs_add_dirt(c, lnum, dlen2);
960 	if (err)
961 		goto out_ro;
962 
963 	dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
964 	err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
965 	if (err)
966 		goto out_ro;
967 
968 	offs += aligned_dlen1 + aligned_dlen2;
969 	if (new_inode) {
970 		ino_key_init(c, &key, new_inode->i_ino);
971 		err = ubifs_tnc_add(c, &key, lnum, offs, ilen);
972 		if (err)
973 			goto out_ro;
974 		offs += ALIGN(ilen, 8);
975 	}
976 
977 	ino_key_init(c, &key, old_dir->i_ino);
978 	err = ubifs_tnc_add(c, &key, lnum, offs, plen);
979 	if (err)
980 		goto out_ro;
981 
982 	if (old_dir != new_dir) {
983 		offs += ALIGN(plen, 8);
984 		ino_key_init(c, &key, new_dir->i_ino);
985 		err = ubifs_tnc_add(c, &key, lnum, offs, plen);
986 		if (err)
987 			goto out_ro;
988 	}
989 
990 	finish_reservation(c);
991 	if (new_inode) {
992 		mark_inode_clean(c, new_ui);
993 		spin_lock(&new_ui->ui_lock);
994 		new_ui->synced_i_size = new_ui->ui_size;
995 		spin_unlock(&new_ui->ui_lock);
996 	}
997 	mark_inode_clean(c, ubifs_inode(old_dir));
998 	if (move)
999 		mark_inode_clean(c, ubifs_inode(new_dir));
1000 	kfree(dent);
1001 	return 0;
1002 
1003 out_release:
1004 	release_head(c, BASEHD);
1005 out_ro:
1006 	ubifs_ro_mode(c, err);
1007 	if (last_reference)
1008 		ubifs_delete_orphan(c, new_inode->i_ino);
1009 out_finish:
1010 	finish_reservation(c);
1011 out_free:
1012 	kfree(dent);
1013 	return err;
1014 }
1015 
1016 /**
1017  * recomp_data_node - re-compress a truncated data node.
1018  * @dn: data node to re-compress
1019  * @new_len: new length
1020  *
1021  * This function is used when an inode is truncated and the last data node of
1022  * the inode has to be re-compressed and re-written.
1023  */
1024 static int recomp_data_node(struct ubifs_data_node *dn, int *new_len)
1025 {
1026 	void *buf;
1027 	int err, len, compr_type, out_len;
1028 
1029 	out_len = le32_to_cpu(dn->size);
1030 	buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
1031 	if (!buf)
1032 		return -ENOMEM;
1033 
1034 	len = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
1035 	compr_type = le16_to_cpu(dn->compr_type);
1036 	err = ubifs_decompress(&dn->data, len, buf, &out_len, compr_type);
1037 	if (err)
1038 		goto out;
1039 
1040 	ubifs_compress(buf, *new_len, &dn->data, &out_len, &compr_type);
1041 	ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
1042 	dn->compr_type = cpu_to_le16(compr_type);
1043 	dn->size = cpu_to_le32(*new_len);
1044 	*new_len = UBIFS_DATA_NODE_SZ + out_len;
1045 out:
1046 	kfree(buf);
1047 	return err;
1048 }
1049 
1050 /**
1051  * ubifs_jnl_truncate - update the journal for a truncation.
1052  * @c: UBIFS file-system description object
1053  * @inode: inode to truncate
1054  * @old_size: old size
1055  * @new_size: new size
1056  *
1057  * When the size of a file decreases due to truncation, a truncation node is
1058  * written, the journal tree is updated, and the last data block is re-written
1059  * if it has been affected. The inode is also updated in order to synchronize
1060  * the new inode size.
1061  *
1062  * This function marks the inode as clean and returns zero on success. In case
1063  * of failure, a negative error code is returned.
1064  */
1065 int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
1066 		       loff_t old_size, loff_t new_size)
1067 {
1068 	union ubifs_key key, to_key;
1069 	struct ubifs_ino_node *ino;
1070 	struct ubifs_trun_node *trun;
1071 	struct ubifs_data_node *uninitialized_var(dn);
1072 	int err, dlen, len, lnum, offs, bit, sz, sync = IS_SYNC(inode);
1073 	struct ubifs_inode *ui = ubifs_inode(inode);
1074 	ino_t inum = inode->i_ino;
1075 	unsigned int blk;
1076 
1077 	dbg_jnl("ino %lu, size %lld -> %lld", inum, old_size, new_size);
1078 	ubifs_assert(!ui->data_len);
1079 	ubifs_assert(S_ISREG(inode->i_mode));
1080 	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
1081 
1082 	sz = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ +
1083 	     UBIFS_MAX_DATA_NODE_SZ * WORST_COMPR_FACTOR;
1084 	ino = kmalloc(sz, GFP_NOFS);
1085 	if (!ino)
1086 		return -ENOMEM;
1087 
1088 	trun = (void *)ino + UBIFS_INO_NODE_SZ;
1089 	trun->ch.node_type = UBIFS_TRUN_NODE;
1090 	trun->inum = cpu_to_le32(inum);
1091 	trun->old_size = cpu_to_le64(old_size);
1092 	trun->new_size = cpu_to_le64(new_size);
1093 	zero_trun_node_unused(trun);
1094 
1095 	dlen = new_size & (UBIFS_BLOCK_SIZE - 1);
1096 	if (dlen) {
1097 		/* Get last data block so it can be truncated */
1098 		dn = (void *)trun + UBIFS_TRUN_NODE_SZ;
1099 		blk = new_size >> UBIFS_BLOCK_SHIFT;
1100 		data_key_init(c, &key, inum, blk);
1101 		dbg_jnl("last block key %s", DBGKEY(&key));
1102 		err = ubifs_tnc_lookup(c, &key, dn);
1103 		if (err == -ENOENT)
1104 			dlen = 0; /* Not found (so it is a hole) */
1105 		else if (err)
1106 			goto out_free;
1107 		else {
1108 			if (le32_to_cpu(dn->size) <= dlen)
1109 				dlen = 0; /* Nothing to do */
1110 			else {
1111 				int compr_type = le16_to_cpu(dn->compr_type);
1112 
1113 				if (compr_type != UBIFS_COMPR_NONE) {
1114 					err = recomp_data_node(dn, &dlen);
1115 					if (err)
1116 						goto out_free;
1117 				} else {
1118 					dn->size = cpu_to_le32(dlen);
1119 					dlen += UBIFS_DATA_NODE_SZ;
1120 				}
1121 				zero_data_node_unused(dn);
1122 			}
1123 		}
1124 	}
1125 
1126 	/* Must make reservation before allocating sequence numbers */
1127 	len = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ;
1128 	if (dlen)
1129 		len += dlen;
1130 	err = make_reservation(c, BASEHD, len);
1131 	if (err)
1132 		goto out_free;
1133 
1134 	pack_inode(c, ino, inode, 0, 0);
1135 	ubifs_prep_grp_node(c, trun, UBIFS_TRUN_NODE_SZ, dlen ? 0 : 1);
1136 	if (dlen)
1137 		ubifs_prep_grp_node(c, dn, dlen, 1);
1138 
1139 	err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
1140 	if (err)
1141 		goto out_release;
1142 	if (!sync)
1143 		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, inum);
1144 	release_head(c, BASEHD);
1145 
1146 	if (dlen) {
1147 		sz = offs + UBIFS_INO_NODE_SZ + UBIFS_TRUN_NODE_SZ;
1148 		err = ubifs_tnc_add(c, &key, lnum, sz, dlen);
1149 		if (err)
1150 			goto out_ro;
1151 	}
1152 
1153 	ino_key_init(c, &key, inum);
1154 	err = ubifs_tnc_add(c, &key, lnum, offs, UBIFS_INO_NODE_SZ);
1155 	if (err)
1156 		goto out_ro;
1157 
1158 	err = ubifs_add_dirt(c, lnum, UBIFS_TRUN_NODE_SZ);
1159 	if (err)
1160 		goto out_ro;
1161 
1162 	bit = new_size & (UBIFS_BLOCK_SIZE - 1);
1163 	blk = (new_size >> UBIFS_BLOCK_SHIFT) + (bit ? 1 : 0);
1164 	data_key_init(c, &key, inum, blk);
1165 
1166 	bit = old_size & (UBIFS_BLOCK_SIZE - 1);
1167 	blk = (old_size >> UBIFS_BLOCK_SHIFT) - (bit ? 0: 1);
1168 	data_key_init(c, &to_key, inum, blk);
1169 
1170 	err = ubifs_tnc_remove_range(c, &key, &to_key);
1171 	if (err)
1172 		goto out_ro;
1173 
1174 	finish_reservation(c);
1175 	spin_lock(&ui->ui_lock);
1176 	ui->synced_i_size = ui->ui_size;
1177 	spin_unlock(&ui->ui_lock);
1178 	mark_inode_clean(c, ui);
1179 	kfree(ino);
1180 	return 0;
1181 
1182 out_release:
1183 	release_head(c, BASEHD);
1184 out_ro:
1185 	ubifs_ro_mode(c, err);
1186 	finish_reservation(c);
1187 out_free:
1188 	kfree(ino);
1189 	return err;
1190 }
1191 
1192 #ifdef CONFIG_UBIFS_FS_XATTR
1193 
1194 /**
1195  * ubifs_jnl_delete_xattr - delete an extended attribute.
1196  * @c: UBIFS file-system description object
1197  * @host: host inode
1198  * @inode: extended attribute inode
1199  * @nm: extended attribute entry name
1200  *
1201  * This function delete an extended attribute which is very similar to
1202  * un-linking regular files - it writes a deletion xentry, a deletion inode and
1203  * updates the target inode. Returns zero in case of success and a negative
1204  * error code in case of failure.
1205  */
1206 int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
1207 			   const struct inode *inode, const struct qstr *nm)
1208 {
1209 	int err, xlen, hlen, len, lnum, xent_offs, aligned_xlen;
1210 	struct ubifs_dent_node *xent;
1211 	struct ubifs_ino_node *ino;
1212 	union ubifs_key xent_key, key1, key2;
1213 	int sync = IS_DIRSYNC(host);
1214 	struct ubifs_inode *host_ui = ubifs_inode(host);
1215 
1216 	dbg_jnl("host %lu, xattr ino %lu, name '%s', data len %d",
1217 		host->i_ino, inode->i_ino, nm->name,
1218 		ubifs_inode(inode)->data_len);
1219 	ubifs_assert(inode->i_nlink == 0);
1220 	ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
1221 
1222 	/*
1223 	 * Since we are deleting the inode, we do not bother to attach any data
1224 	 * to it and assume its length is %UBIFS_INO_NODE_SZ.
1225 	 */
1226 	xlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
1227 	aligned_xlen = ALIGN(xlen, 8);
1228 	hlen = host_ui->data_len + UBIFS_INO_NODE_SZ;
1229 	len = aligned_xlen + UBIFS_INO_NODE_SZ + ALIGN(hlen, 8);
1230 
1231 	xent = kmalloc(len, GFP_NOFS);
1232 	if (!xent)
1233 		return -ENOMEM;
1234 
1235 	/* Make reservation before allocating sequence numbers */
1236 	err = make_reservation(c, BASEHD, len);
1237 	if (err) {
1238 		kfree(xent);
1239 		return err;
1240 	}
1241 
1242 	xent->ch.node_type = UBIFS_XENT_NODE;
1243 	xent_key_init(c, &xent_key, host->i_ino, nm);
1244 	key_write(c, &xent_key, xent->key);
1245 	xent->inum = 0;
1246 	xent->type = get_dent_type(inode->i_mode);
1247 	xent->nlen = cpu_to_le16(nm->len);
1248 	memcpy(xent->name, nm->name, nm->len);
1249 	xent->name[nm->len] = '\0';
1250 	zero_dent_node_unused(xent);
1251 	ubifs_prep_grp_node(c, xent, xlen, 0);
1252 
1253 	ino = (void *)xent + aligned_xlen;
1254 	pack_inode(c, ino, inode, 0, 1);
1255 	ino = (void *)ino + UBIFS_INO_NODE_SZ;
1256 	pack_inode(c, ino, host, 1, 0);
1257 
1258 	err = write_head(c, BASEHD, xent, len, &lnum, &xent_offs, sync);
1259 	if (!sync && !err)
1260 		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, host->i_ino);
1261 	release_head(c, BASEHD);
1262 	kfree(xent);
1263 	if (err)
1264 		goto out_ro;
1265 
1266 	/* Remove the extended attribute entry from TNC */
1267 	err = ubifs_tnc_remove_nm(c, &xent_key, nm);
1268 	if (err)
1269 		goto out_ro;
1270 	err = ubifs_add_dirt(c, lnum, xlen);
1271 	if (err)
1272 		goto out_ro;
1273 
1274 	/*
1275 	 * Remove all nodes belonging to the extended attribute inode from TNC.
1276 	 * Well, there actually must be only one node - the inode itself.
1277 	 */
1278 	lowest_ino_key(c, &key1, inode->i_ino);
1279 	highest_ino_key(c, &key2, inode->i_ino);
1280 	err = ubifs_tnc_remove_range(c, &key1, &key2);
1281 	if (err)
1282 		goto out_ro;
1283 	err = ubifs_add_dirt(c, lnum, UBIFS_INO_NODE_SZ);
1284 	if (err)
1285 		goto out_ro;
1286 
1287 	/* And update TNC with the new host inode position */
1288 	ino_key_init(c, &key1, host->i_ino);
1289 	err = ubifs_tnc_add(c, &key1, lnum, xent_offs + len - hlen, hlen);
1290 	if (err)
1291 		goto out_ro;
1292 
1293 	finish_reservation(c);
1294 	spin_lock(&host_ui->ui_lock);
1295 	host_ui->synced_i_size = host_ui->ui_size;
1296 	spin_unlock(&host_ui->ui_lock);
1297 	mark_inode_clean(c, host_ui);
1298 	return 0;
1299 
1300 out_ro:
1301 	ubifs_ro_mode(c, err);
1302 	finish_reservation(c);
1303 	return err;
1304 }
1305 
1306 /**
1307  * ubifs_jnl_change_xattr - change an extended attribute.
1308  * @c: UBIFS file-system description object
1309  * @inode: extended attribute inode
1310  * @host: host inode
1311  *
1312  * This function writes the updated version of an extended attribute inode and
1313  * the host inode tho the journal (to the base head). The host inode is written
1314  * after the extended attribute inode in order to guarantee that the extended
1315  * attribute will be flushed when the inode is synchronized by 'fsync()' and
1316  * consequently, the write-buffer is synchronized. This function returns zero
1317  * in case of success and a negative error code in case of failure.
1318  */
1319 int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode,
1320 			   const struct inode *host)
1321 {
1322 	int err, len1, len2, aligned_len, aligned_len1, lnum, offs;
1323 	struct ubifs_inode *host_ui = ubifs_inode(inode);
1324 	struct ubifs_ino_node *ino;
1325 	union ubifs_key key;
1326 	int sync = IS_DIRSYNC(host);
1327 
1328 	dbg_jnl("ino %lu, ino %lu", host->i_ino, inode->i_ino);
1329 	ubifs_assert(host->i_nlink > 0);
1330 	ubifs_assert(inode->i_nlink > 0);
1331 	ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
1332 
1333 	len1 = UBIFS_INO_NODE_SZ + host_ui->data_len;
1334 	len2 = UBIFS_INO_NODE_SZ + ubifs_inode(inode)->data_len;
1335 	aligned_len1 = ALIGN(len1, 8);
1336 	aligned_len = aligned_len1 + ALIGN(len2, 8);
1337 
1338 	ino = kmalloc(aligned_len, GFP_NOFS);
1339 	if (!ino)
1340 		return -ENOMEM;
1341 
1342 	/* Make reservation before allocating sequence numbers */
1343 	err = make_reservation(c, BASEHD, aligned_len);
1344 	if (err)
1345 		goto out_free;
1346 
1347 	pack_inode(c, ino, host, 0, 0);
1348 	pack_inode(c, (void *)ino + aligned_len1, inode, 1, 0);
1349 
1350 	err = write_head(c, BASEHD, ino, aligned_len, &lnum, &offs, 0);
1351 	if (!sync && !err) {
1352 		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
1353 
1354 		ubifs_wbuf_add_ino_nolock(wbuf, host->i_ino);
1355 		ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
1356 	}
1357 	release_head(c, BASEHD);
1358 	if (err)
1359 		goto out_ro;
1360 
1361 	ino_key_init(c, &key, host->i_ino);
1362 	err = ubifs_tnc_add(c, &key, lnum, offs, len1);
1363 	if (err)
1364 		goto out_ro;
1365 
1366 	ino_key_init(c, &key, inode->i_ino);
1367 	err = ubifs_tnc_add(c, &key, lnum, offs + aligned_len1, len2);
1368 	if (err)
1369 		goto out_ro;
1370 
1371 	finish_reservation(c);
1372 	spin_lock(&host_ui->ui_lock);
1373 	host_ui->synced_i_size = host_ui->ui_size;
1374 	spin_unlock(&host_ui->ui_lock);
1375 	mark_inode_clean(c, host_ui);
1376 	kfree(ino);
1377 	return 0;
1378 
1379 out_ro:
1380 	ubifs_ro_mode(c, err);
1381 	finish_reservation(c);
1382 out_free:
1383 	kfree(ino);
1384 	return err;
1385 }
1386 
1387 #endif /* CONFIG_UBIFS_FS_XATTR */
1388