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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Stefan Roese9eefe2a2009-03-19 15:35:05 +01002/*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 * Copyright (C) 2006, 2007 University of Szeged, Hungary
7 *
Stefan Roese9eefe2a2009-03-19 15:35:05 +01008 * Authors: Artem Bityutskiy (Битюцкий Артём)
9 * Adrian Hunter
10 * Zoltan Sogor
11 */
12
13/*
14 * This file implements UBIFS I/O subsystem which provides various I/O-related
15 * helper functions (reading/writing/checking/validating nodes) and implements
16 * write-buffering support. Write buffers help to save space which otherwise
17 * would have been wasted for padding to the nearest minimal I/O unit boundary.
18 * Instead, data first goes to the write-buffer and is flushed when the
19 * buffer is full or when it is not used for some time (by timer). This is
20 * similar to the mechanism is used by JFFS2.
21 *
Heiko Schocherff94bc42014-06-24 10:10:04 +020022 * UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum
23 * write size (@c->max_write_size). The latter is the maximum amount of bytes
24 * the underlying flash is able to program at a time, and writing in
25 * @c->max_write_size units should presumably be faster. Obviously,
26 * @c->min_io_size <= @c->max_write_size. Write-buffers are of
27 * @c->max_write_size bytes in size for maximum performance. However, when a
28 * write-buffer is flushed, only the portion of it (aligned to @c->min_io_size
29 * boundary) which contains data is written, not the whole write-buffer,
30 * because this is more space-efficient.
31 *
32 * This optimization adds few complications to the code. Indeed, on the one
33 * hand, we want to write in optimal @c->max_write_size bytes chunks, which
34 * also means aligning writes at the @c->max_write_size bytes offsets. On the
35 * other hand, we do not want to waste space when synchronizing the write
36 * buffer, so during synchronization we writes in smaller chunks. And this makes
37 * the next write offset to be not aligned to @c->max_write_size bytes. So the
38 * have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned
39 * to @c->max_write_size bytes again. We do this by temporarily shrinking
40 * write-buffer size (@wbuf->size).
41 *
Stefan Roese9eefe2a2009-03-19 15:35:05 +010042 * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by
43 * mutexes defined inside these objects. Since sometimes upper-level code
44 * has to lock the write-buffer (e.g. journal space reservation code), many
45 * functions related to write-buffers have "nolock" suffix which means that the
46 * caller has to lock the write-buffer before calling this function.
47 *
48 * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not
49 * aligned, UBIFS starts the next node from the aligned address, and the padded
50 * bytes may contain any rubbish. In other words, UBIFS does not put padding
51 * bytes in those small gaps. Common headers of nodes store real node lengths,
52 * not aligned lengths. Indexing nodes also store real lengths in branches.
53 *
54 * UBIFS uses padding when it pads to the next min. I/O unit. In this case it
55 * uses padding nodes or padding bytes, if the padding node does not fit.
56 *
Heiko Schocherff94bc42014-06-24 10:10:04 +020057 * All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when
58 * they are read from the flash media.
Stefan Roese9eefe2a2009-03-19 15:35:05 +010059 */
60
Heiko Schocherff94bc42014-06-24 10:10:04 +020061#ifndef __UBOOT__
62#include <linux/crc32.h>
63#include <linux/slab.h>
64#else
65#include <linux/compat.h>
66#include <linux/err.h>
67#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +010068#include "ubifs.h"
69
70/**
71 * ubifs_ro_mode - switch UBIFS to read read-only mode.
72 * @c: UBIFS file-system description object
73 * @err: error code which is the reason of switching to R/O mode
74 */
75void ubifs_ro_mode(struct ubifs_info *c, int err)
76{
Heiko Schocherff94bc42014-06-24 10:10:04 +020077 if (!c->ro_error) {
78 c->ro_error = 1;
Stefan Roese9eefe2a2009-03-19 15:35:05 +010079 c->no_chk_data_crc = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +020080 c->vfs_sb->s_flags |= MS_RDONLY;
Heiko Schocher0195a7b2015-10-22 06:19:21 +020081 ubifs_warn(c, "switched to read-only mode, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +020082 dump_stack();
Stefan Roese9eefe2a2009-03-19 15:35:05 +010083 }
84}
85
Heiko Schocherff94bc42014-06-24 10:10:04 +020086/*
87 * Below are simple wrappers over UBI I/O functions which include some
88 * additional checks and UBIFS debugging stuff. See corresponding UBI function
89 * for more information.
90 */
91
92int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs,
93 int len, int even_ebadmsg)
94{
95 int err;
96
97 err = ubi_read(c->ubi, lnum, buf, offs, len);
98 /*
99 * In case of %-EBADMSG print the error message only if the
100 * @even_ebadmsg is true.
101 */
102 if (err && (err != -EBADMSG || even_ebadmsg)) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200103 ubifs_err(c, "reading %d bytes from LEB %d:%d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200104 len, lnum, offs, err);
105 dump_stack();
106 }
107 return err;
108}
109
110int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs,
111 int len)
112{
113 int err;
114
115 ubifs_assert(!c->ro_media && !c->ro_mount);
116 if (c->ro_error)
117 return -EROFS;
118 if (!dbg_is_tst_rcvry(c))
119 err = ubi_leb_write(c->ubi, lnum, buf, offs, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200120#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200121 else
122 err = dbg_leb_write(c, lnum, buf, offs, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200123#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200124 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200125 ubifs_err(c, "writing %d bytes to LEB %d:%d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200126 len, lnum, offs, err);
127 ubifs_ro_mode(c, err);
128 dump_stack();
129 }
130 return err;
131}
132
133int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len)
134{
135 int err;
136
137 ubifs_assert(!c->ro_media && !c->ro_mount);
138 if (c->ro_error)
139 return -EROFS;
140 if (!dbg_is_tst_rcvry(c))
141 err = ubi_leb_change(c->ubi, lnum, buf, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200142#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200143 else
144 err = dbg_leb_change(c, lnum, buf, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200145#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200146 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200147 ubifs_err(c, "changing %d bytes in LEB %d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200148 len, lnum, err);
149 ubifs_ro_mode(c, err);
150 dump_stack();
151 }
152 return err;
153}
154
155int ubifs_leb_unmap(struct ubifs_info *c, int lnum)
156{
157 int err;
158
159 ubifs_assert(!c->ro_media && !c->ro_mount);
160 if (c->ro_error)
161 return -EROFS;
162 if (!dbg_is_tst_rcvry(c))
163 err = ubi_leb_unmap(c->ubi, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200164#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200165 else
166 err = dbg_leb_unmap(c, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200167#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200168 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200169 ubifs_err(c, "unmap LEB %d failed, error %d", lnum, err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200170 ubifs_ro_mode(c, err);
171 dump_stack();
172 }
173 return err;
174}
175
176int ubifs_leb_map(struct ubifs_info *c, int lnum)
177{
178 int err;
179
180 ubifs_assert(!c->ro_media && !c->ro_mount);
181 if (c->ro_error)
182 return -EROFS;
183 if (!dbg_is_tst_rcvry(c))
184 err = ubi_leb_map(c->ubi, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200185#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200186 else
187 err = dbg_leb_map(c, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200188#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200189 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200190 ubifs_err(c, "mapping LEB %d failed, error %d", lnum, err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200191 ubifs_ro_mode(c, err);
192 dump_stack();
193 }
194 return err;
195}
196
197int ubifs_is_mapped(const struct ubifs_info *c, int lnum)
198{
199 int err;
200
201 err = ubi_is_mapped(c->ubi, lnum);
202 if (err < 0) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200203 ubifs_err(c, "ubi_is_mapped failed for LEB %d, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200204 lnum, err);
205 dump_stack();
206 }
207 return err;
208}
209
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100210/**
211 * ubifs_check_node - check node.
212 * @c: UBIFS file-system description object
213 * @buf: node to check
214 * @lnum: logical eraseblock number
215 * @offs: offset within the logical eraseblock
216 * @quiet: print no messages
217 * @must_chk_crc: indicates whether to always check the CRC
218 *
219 * This function checks node magic number and CRC checksum. This function also
220 * validates node length to prevent UBIFS from becoming crazy when an attacker
221 * feeds it a file-system image with incorrect nodes. For example, too large
222 * node length in the common header could cause UBIFS to read memory outside of
223 * allocated buffer when checking the CRC checksum.
224 *
225 * This function may skip data nodes CRC checking if @c->no_chk_data_crc is
226 * true, which is controlled by corresponding UBIFS mount option. However, if
227 * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is
Heiko Schocherff94bc42014-06-24 10:10:04 +0200228 * checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are
229 * mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC
230 * is checked. This is because during mounting or re-mounting from R/O mode to
231 * R/W mode we may read journal nodes (when replying the journal or doing the
232 * recovery) and the journal nodes may potentially be corrupted, so checking is
233 * required.
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100234 *
235 * This function returns zero in case of success and %-EUCLEAN in case of bad
236 * CRC or magic.
237 */
238int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
239 int offs, int quiet, int must_chk_crc)
240{
241 int err = -EINVAL, type, node_len;
242 uint32_t crc, node_crc, magic;
243 const struct ubifs_ch *ch = buf;
244
245 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
246 ubifs_assert(!(offs & 7) && offs < c->leb_size);
247
248 magic = le32_to_cpu(ch->magic);
249 if (magic != UBIFS_NODE_MAGIC) {
250 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200251 ubifs_err(c, "bad magic %#08x, expected %#08x",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100252 magic, UBIFS_NODE_MAGIC);
253 err = -EUCLEAN;
254 goto out;
255 }
256
257 type = ch->node_type;
258 if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) {
259 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200260 ubifs_err(c, "bad node type %d", type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100261 goto out;
262 }
263
264 node_len = le32_to_cpu(ch->len);
265 if (node_len + offs > c->leb_size)
266 goto out_len;
267
268 if (c->ranges[type].max_len == 0) {
269 if (node_len != c->ranges[type].len)
270 goto out_len;
271 } else if (node_len < c->ranges[type].min_len ||
272 node_len > c->ranges[type].max_len)
273 goto out_len;
274
Heiko Schocherff94bc42014-06-24 10:10:04 +0200275 if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting &&
276 !c->remounting_rw && c->no_chk_data_crc)
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100277 return 0;
278
279 crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
280 node_crc = le32_to_cpu(ch->crc);
281 if (crc != node_crc) {
282 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200283 ubifs_err(c, "bad CRC: calculated %#08x, read %#08x",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100284 crc, node_crc);
285 err = -EUCLEAN;
286 goto out;
287 }
288
289 return 0;
290
291out_len:
292 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200293 ubifs_err(c, "bad node length %d", node_len);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100294out:
295 if (!quiet) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200296 ubifs_err(c, "bad node at LEB %d:%d", lnum, offs);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200297 ubifs_dump_node(c, buf);
298 dump_stack();
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100299 }
300 return err;
301}
302
303/**
304 * ubifs_pad - pad flash space.
305 * @c: UBIFS file-system description object
306 * @buf: buffer to put padding to
307 * @pad: how many bytes to pad
308 *
309 * The flash media obliges us to write only in chunks of %c->min_io_size and
310 * when we have to write less data we add padding node to the write-buffer and
311 * pad it to the next minimal I/O unit's boundary. Padding nodes help when the
312 * media is being scanned. If the amount of wasted space is not enough to fit a
313 * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes
314 * pattern (%UBIFS_PADDING_BYTE).
315 *
316 * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
317 * used.
318 */
319void ubifs_pad(const struct ubifs_info *c, void *buf, int pad)
320{
321 uint32_t crc;
322
323 ubifs_assert(pad >= 0 && !(pad & 7));
324
325 if (pad >= UBIFS_PAD_NODE_SZ) {
326 struct ubifs_ch *ch = buf;
327 struct ubifs_pad_node *pad_node = buf;
328
329 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
330 ch->node_type = UBIFS_PAD_NODE;
331 ch->group_type = UBIFS_NO_NODE_GROUP;
332 ch->padding[0] = ch->padding[1] = 0;
333 ch->sqnum = 0;
334 ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ);
335 pad -= UBIFS_PAD_NODE_SZ;
336 pad_node->pad_len = cpu_to_le32(pad);
337 crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8);
338 ch->crc = cpu_to_le32(crc);
339 memset(buf + UBIFS_PAD_NODE_SZ, 0, pad);
340 } else if (pad > 0)
341 /* Too little space, padding node won't fit */
342 memset(buf, UBIFS_PADDING_BYTE, pad);
343}
344
345/**
346 * next_sqnum - get next sequence number.
347 * @c: UBIFS file-system description object
348 */
349static unsigned long long next_sqnum(struct ubifs_info *c)
350{
351 unsigned long long sqnum;
352
353 spin_lock(&c->cnt_lock);
354 sqnum = ++c->max_sqnum;
355 spin_unlock(&c->cnt_lock);
356
357 if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) {
358 if (sqnum >= SQNUM_WATERMARK) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200359 ubifs_err(c, "sequence number overflow %llu, end of life",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100360 sqnum);
361 ubifs_ro_mode(c, -EINVAL);
362 }
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200363 ubifs_warn(c, "running out of sequence numbers, end of life soon");
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100364 }
365
366 return sqnum;
367}
368
369/**
370 * ubifs_prepare_node - prepare node to be written to flash.
371 * @c: UBIFS file-system description object
372 * @node: the node to pad
373 * @len: node length
374 * @pad: if the buffer has to be padded
375 *
376 * This function prepares node at @node to be written to the media - it
377 * calculates node CRC, fills the common header, and adds proper padding up to
378 * the next minimum I/O unit if @pad is not zero.
379 */
380void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
381{
382 uint32_t crc;
383 struct ubifs_ch *ch = node;
384 unsigned long long sqnum = next_sqnum(c);
385
386 ubifs_assert(len >= UBIFS_CH_SZ);
387
388 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
389 ch->len = cpu_to_le32(len);
390 ch->group_type = UBIFS_NO_NODE_GROUP;
391 ch->sqnum = cpu_to_le64(sqnum);
392 ch->padding[0] = ch->padding[1] = 0;
393 crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
394 ch->crc = cpu_to_le32(crc);
395
396 if (pad) {
397 len = ALIGN(len, 8);
398 pad = ALIGN(len, c->min_io_size) - len;
399 ubifs_pad(c, node + len, pad);
400 }
401}
402
403/**
Heiko Schocherff94bc42014-06-24 10:10:04 +0200404 * ubifs_prep_grp_node - prepare node of a group to be written to flash.
405 * @c: UBIFS file-system description object
406 * @node: the node to pad
407 * @len: node length
408 * @last: indicates the last node of the group
409 *
410 * This function prepares node at @node to be written to the media - it
411 * calculates node CRC and fills the common header.
412 */
413void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last)
414{
415 uint32_t crc;
416 struct ubifs_ch *ch = node;
417 unsigned long long sqnum = next_sqnum(c);
418
419 ubifs_assert(len >= UBIFS_CH_SZ);
420
421 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
422 ch->len = cpu_to_le32(len);
423 if (last)
424 ch->group_type = UBIFS_LAST_OF_NODE_GROUP;
425 else
426 ch->group_type = UBIFS_IN_NODE_GROUP;
427 ch->sqnum = cpu_to_le64(sqnum);
428 ch->padding[0] = ch->padding[1] = 0;
429 crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
430 ch->crc = cpu_to_le32(crc);
431}
432
433#ifndef __UBOOT__
434/**
435 * wbuf_timer_callback - write-buffer timer callback function.
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200436 * @timer: timer data (write-buffer descriptor)
Heiko Schocherff94bc42014-06-24 10:10:04 +0200437 *
438 * This function is called when the write-buffer timer expires.
439 */
440static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer)
441{
442 struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer);
443
444 dbg_io("jhead %s", dbg_jhead(wbuf->jhead));
445 wbuf->need_sync = 1;
446 wbuf->c->need_wbuf_sync = 1;
447 ubifs_wake_up_bgt(wbuf->c);
448 return HRTIMER_NORESTART;
449}
450
451/**
452 * new_wbuf_timer - start new write-buffer timer.
453 * @wbuf: write-buffer descriptor
454 */
455static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
456{
457 ubifs_assert(!hrtimer_active(&wbuf->timer));
458
459 if (wbuf->no_timer)
460 return;
461 dbg_io("set timer for jhead %s, %llu-%llu millisecs",
462 dbg_jhead(wbuf->jhead),
463 div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC),
464 div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta,
465 USEC_PER_SEC));
466 hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta,
467 HRTIMER_MODE_REL);
468}
469#endif
470
471/**
472 * cancel_wbuf_timer - cancel write-buffer timer.
473 * @wbuf: write-buffer descriptor
474 */
475static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
476{
477 if (wbuf->no_timer)
478 return;
479 wbuf->need_sync = 0;
480#ifndef __UBOOT__
481 hrtimer_cancel(&wbuf->timer);
482#endif
483}
484
485/**
486 * ubifs_wbuf_sync_nolock - synchronize write-buffer.
487 * @wbuf: write-buffer to synchronize
488 *
489 * This function synchronizes write-buffer @buf and returns zero in case of
490 * success or a negative error code in case of failure.
491 *
492 * Note, although write-buffers are of @c->max_write_size, this function does
493 * not necessarily writes all @c->max_write_size bytes to the flash. Instead,
494 * if the write-buffer is only partially filled with data, only the used part
495 * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized.
496 * This way we waste less space.
497 */
498int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
499{
500 struct ubifs_info *c = wbuf->c;
501 int err, dirt, sync_len;
502
503 cancel_wbuf_timer_nolock(wbuf);
504 if (!wbuf->used || wbuf->lnum == -1)
505 /* Write-buffer is empty or not seeked */
506 return 0;
507
508 dbg_io("LEB %d:%d, %d bytes, jhead %s",
509 wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead));
510 ubifs_assert(!(wbuf->avail & 7));
511 ubifs_assert(wbuf->offs + wbuf->size <= c->leb_size);
512 ubifs_assert(wbuf->size >= c->min_io_size);
513 ubifs_assert(wbuf->size <= c->max_write_size);
514 ubifs_assert(wbuf->size % c->min_io_size == 0);
515 ubifs_assert(!c->ro_media && !c->ro_mount);
516 if (c->leb_size - wbuf->offs >= c->max_write_size)
517 ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size));
518
519 if (c->ro_error)
520 return -EROFS;
521
522 /*
523 * Do not write whole write buffer but write only the minimum necessary
524 * amount of min. I/O units.
525 */
526 sync_len = ALIGN(wbuf->used, c->min_io_size);
527 dirt = sync_len - wbuf->used;
528 if (dirt)
529 ubifs_pad(c, wbuf->buf + wbuf->used, dirt);
530 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len);
531 if (err)
532 return err;
533
534 spin_lock(&wbuf->lock);
535 wbuf->offs += sync_len;
536 /*
537 * Now @wbuf->offs is not necessarily aligned to @c->max_write_size.
538 * But our goal is to optimize writes and make sure we write in
539 * @c->max_write_size chunks and to @c->max_write_size-aligned offset.
540 * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make
541 * sure that @wbuf->offs + @wbuf->size is aligned to
542 * @c->max_write_size. This way we make sure that after next
543 * write-buffer flush we are again at the optimal offset (aligned to
544 * @c->max_write_size).
545 */
546 if (c->leb_size - wbuf->offs < c->max_write_size)
547 wbuf->size = c->leb_size - wbuf->offs;
548 else if (wbuf->offs & (c->max_write_size - 1))
549 wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs;
550 else
551 wbuf->size = c->max_write_size;
552 wbuf->avail = wbuf->size;
553 wbuf->used = 0;
554 wbuf->next_ino = 0;
555 spin_unlock(&wbuf->lock);
556
557 if (wbuf->sync_callback)
558 err = wbuf->sync_callback(c, wbuf->lnum,
559 c->leb_size - wbuf->offs, dirt);
560 return err;
561}
562
563/**
564 * ubifs_wbuf_seek_nolock - seek write-buffer.
565 * @wbuf: write-buffer
566 * @lnum: logical eraseblock number to seek to
567 * @offs: logical eraseblock offset to seek to
568 *
569 * This function targets the write-buffer to logical eraseblock @lnum:@offs.
570 * The write-buffer has to be empty. Returns zero in case of success and a
571 * negative error code in case of failure.
572 */
573int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs)
574{
575 const struct ubifs_info *c = wbuf->c;
576
577 dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead));
578 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt);
579 ubifs_assert(offs >= 0 && offs <= c->leb_size);
580 ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7));
581 ubifs_assert(lnum != wbuf->lnum);
582 ubifs_assert(wbuf->used == 0);
583
584 spin_lock(&wbuf->lock);
585 wbuf->lnum = lnum;
586 wbuf->offs = offs;
587 if (c->leb_size - wbuf->offs < c->max_write_size)
588 wbuf->size = c->leb_size - wbuf->offs;
589 else if (wbuf->offs & (c->max_write_size - 1))
590 wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs;
591 else
592 wbuf->size = c->max_write_size;
593 wbuf->avail = wbuf->size;
594 wbuf->used = 0;
595 spin_unlock(&wbuf->lock);
596
597 return 0;
598}
599
600#ifndef __UBOOT__
601/**
602 * ubifs_bg_wbufs_sync - synchronize write-buffers.
603 * @c: UBIFS file-system description object
604 *
605 * This function is called by background thread to synchronize write-buffers.
606 * Returns zero in case of success and a negative error code in case of
607 * failure.
608 */
609int ubifs_bg_wbufs_sync(struct ubifs_info *c)
610{
611 int err, i;
612
613 ubifs_assert(!c->ro_media && !c->ro_mount);
614 if (!c->need_wbuf_sync)
615 return 0;
616 c->need_wbuf_sync = 0;
617
618 if (c->ro_error) {
619 err = -EROFS;
620 goto out_timers;
621 }
622
623 dbg_io("synchronize");
624 for (i = 0; i < c->jhead_cnt; i++) {
625 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
626
627 cond_resched();
628
629 /*
630 * If the mutex is locked then wbuf is being changed, so
631 * synchronization is not necessary.
632 */
633 if (mutex_is_locked(&wbuf->io_mutex))
634 continue;
635
636 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
637 if (!wbuf->need_sync) {
638 mutex_unlock(&wbuf->io_mutex);
639 continue;
640 }
641
642 err = ubifs_wbuf_sync_nolock(wbuf);
643 mutex_unlock(&wbuf->io_mutex);
644 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200645 ubifs_err(c, "cannot sync write-buffer, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200646 ubifs_ro_mode(c, err);
647 goto out_timers;
648 }
649 }
650
651 return 0;
652
653out_timers:
654 /* Cancel all timers to prevent repeated errors */
655 for (i = 0; i < c->jhead_cnt; i++) {
656 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
657
658 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
659 cancel_wbuf_timer_nolock(wbuf);
660 mutex_unlock(&wbuf->io_mutex);
661 }
662 return err;
663}
664
665/**
666 * ubifs_wbuf_write_nolock - write data to flash via write-buffer.
667 * @wbuf: write-buffer
668 * @buf: node to write
669 * @len: node length
670 *
671 * This function writes data to flash via write-buffer @wbuf. This means that
672 * the last piece of the node won't reach the flash media immediately if it
673 * does not take whole max. write unit (@c->max_write_size). Instead, the node
674 * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or
675 * because more data are appended to the write-buffer).
676 *
677 * This function returns zero in case of success and a negative error code in
678 * case of failure. If the node cannot be written because there is no more
679 * space in this logical eraseblock, %-ENOSPC is returned.
680 */
681int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
682{
683 struct ubifs_info *c = wbuf->c;
684 int err, written, n, aligned_len = ALIGN(len, 8);
685
686 dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len,
687 dbg_ntype(((struct ubifs_ch *)buf)->node_type),
688 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used);
689 ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt);
690 ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0);
691 ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
692 ubifs_assert(wbuf->avail > 0 && wbuf->avail <= wbuf->size);
693 ubifs_assert(wbuf->size >= c->min_io_size);
694 ubifs_assert(wbuf->size <= c->max_write_size);
695 ubifs_assert(wbuf->size % c->min_io_size == 0);
696 ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
697 ubifs_assert(!c->ro_media && !c->ro_mount);
698 ubifs_assert(!c->space_fixup);
699 if (c->leb_size - wbuf->offs >= c->max_write_size)
700 ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size));
701
702 if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
703 err = -ENOSPC;
704 goto out;
705 }
706
707 cancel_wbuf_timer_nolock(wbuf);
708
709 if (c->ro_error)
710 return -EROFS;
711
712 if (aligned_len <= wbuf->avail) {
713 /*
714 * The node is not very large and fits entirely within
715 * write-buffer.
716 */
717 memcpy(wbuf->buf + wbuf->used, buf, len);
718
719 if (aligned_len == wbuf->avail) {
720 dbg_io("flush jhead %s wbuf to LEB %d:%d",
721 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
722 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf,
723 wbuf->offs, wbuf->size);
724 if (err)
725 goto out;
726
727 spin_lock(&wbuf->lock);
728 wbuf->offs += wbuf->size;
729 if (c->leb_size - wbuf->offs >= c->max_write_size)
730 wbuf->size = c->max_write_size;
731 else
732 wbuf->size = c->leb_size - wbuf->offs;
733 wbuf->avail = wbuf->size;
734 wbuf->used = 0;
735 wbuf->next_ino = 0;
736 spin_unlock(&wbuf->lock);
737 } else {
738 spin_lock(&wbuf->lock);
739 wbuf->avail -= aligned_len;
740 wbuf->used += aligned_len;
741 spin_unlock(&wbuf->lock);
742 }
743
744 goto exit;
745 }
746
747 written = 0;
748
749 if (wbuf->used) {
750 /*
751 * The node is large enough and does not fit entirely within
752 * current available space. We have to fill and flush
753 * write-buffer and switch to the next max. write unit.
754 */
755 dbg_io("flush jhead %s wbuf to LEB %d:%d",
756 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
757 memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail);
758 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs,
759 wbuf->size);
760 if (err)
761 goto out;
762
763 wbuf->offs += wbuf->size;
764 len -= wbuf->avail;
765 aligned_len -= wbuf->avail;
766 written += wbuf->avail;
767 } else if (wbuf->offs & (c->max_write_size - 1)) {
768 /*
769 * The write-buffer offset is not aligned to
770 * @c->max_write_size and @wbuf->size is less than
771 * @c->max_write_size. Write @wbuf->size bytes to make sure the
772 * following writes are done in optimal @c->max_write_size
773 * chunks.
774 */
775 dbg_io("write %d bytes to LEB %d:%d",
776 wbuf->size, wbuf->lnum, wbuf->offs);
777 err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs,
778 wbuf->size);
779 if (err)
780 goto out;
781
782 wbuf->offs += wbuf->size;
783 len -= wbuf->size;
784 aligned_len -= wbuf->size;
785 written += wbuf->size;
786 }
787
788 /*
789 * The remaining data may take more whole max. write units, so write the
790 * remains multiple to max. write unit size directly to the flash media.
791 * We align node length to 8-byte boundary because we anyway flash wbuf
792 * if the remaining space is less than 8 bytes.
793 */
794 n = aligned_len >> c->max_write_shift;
795 if (n) {
796 n <<= c->max_write_shift;
797 dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum,
798 wbuf->offs);
799 err = ubifs_leb_write(c, wbuf->lnum, buf + written,
800 wbuf->offs, n);
801 if (err)
802 goto out;
803 wbuf->offs += n;
804 aligned_len -= n;
805 len -= n;
806 written += n;
807 }
808
809 spin_lock(&wbuf->lock);
810 if (aligned_len)
811 /*
812 * And now we have what's left and what does not take whole
813 * max. write unit, so write it to the write-buffer and we are
814 * done.
815 */
816 memcpy(wbuf->buf, buf + written, len);
817
818 if (c->leb_size - wbuf->offs >= c->max_write_size)
819 wbuf->size = c->max_write_size;
820 else
821 wbuf->size = c->leb_size - wbuf->offs;
822 wbuf->avail = wbuf->size - aligned_len;
823 wbuf->used = aligned_len;
824 wbuf->next_ino = 0;
825 spin_unlock(&wbuf->lock);
826
827exit:
828 if (wbuf->sync_callback) {
829 int free = c->leb_size - wbuf->offs - wbuf->used;
830
831 err = wbuf->sync_callback(c, wbuf->lnum, free, 0);
832 if (err)
833 goto out;
834 }
835
836 if (wbuf->used)
837 new_wbuf_timer_nolock(wbuf);
838
839 return 0;
840
841out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200842 ubifs_err(c, "cannot write %d bytes to LEB %d:%d, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200843 len, wbuf->lnum, wbuf->offs, err);
844 ubifs_dump_node(c, buf);
845 dump_stack();
846 ubifs_dump_leb(c, wbuf->lnum);
847 return err;
848}
849
850/**
851 * ubifs_write_node - write node to the media.
852 * @c: UBIFS file-system description object
853 * @buf: the node to write
854 * @len: node length
855 * @lnum: logical eraseblock number
856 * @offs: offset within the logical eraseblock
857 *
858 * This function automatically fills node magic number, assigns sequence
859 * number, and calculates node CRC checksum. The length of the @buf buffer has
860 * to be aligned to the minimal I/O unit size. This function automatically
861 * appends padding node and padding bytes if needed. Returns zero in case of
862 * success and a negative error code in case of failure.
863 */
864int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
865 int offs)
866{
867 int err, buf_len = ALIGN(len, c->min_io_size);
868
869 dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
870 lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len,
871 buf_len);
872 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
873 ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);
874 ubifs_assert(!c->ro_media && !c->ro_mount);
875 ubifs_assert(!c->space_fixup);
876
877 if (c->ro_error)
878 return -EROFS;
879
880 ubifs_prepare_node(c, buf, len, 1);
881 err = ubifs_leb_write(c, lnum, buf, offs, buf_len);
882 if (err)
883 ubifs_dump_node(c, buf);
884
885 return err;
886}
887#endif
888
889/**
890 * ubifs_read_node_wbuf - read node from the media or write-buffer.
891 * @wbuf: wbuf to check for un-written data
892 * @buf: buffer to read to
893 * @type: node type
894 * @len: node length
895 * @lnum: logical eraseblock number
896 * @offs: offset within the logical eraseblock
897 *
898 * This function reads a node of known type and length, checks it and stores
899 * in @buf. If the node partially or fully sits in the write-buffer, this
900 * function takes data from the buffer, otherwise it reads the flash media.
901 * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
902 * error code in case of failure.
903 */
904int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
905 int lnum, int offs)
906{
907 const struct ubifs_info *c = wbuf->c;
908 int err, rlen, overlap;
909 struct ubifs_ch *ch = buf;
910
911 dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs,
912 dbg_ntype(type), len, dbg_jhead(wbuf->jhead));
913 ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
914 ubifs_assert(!(offs & 7) && offs < c->leb_size);
915 ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
916
917 spin_lock(&wbuf->lock);
918 overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
919 if (!overlap) {
920 /* We may safely unlock the write-buffer and read the data */
921 spin_unlock(&wbuf->lock);
922 return ubifs_read_node(c, buf, type, len, lnum, offs);
923 }
924
925 /* Don't read under wbuf */
926 rlen = wbuf->offs - offs;
927 if (rlen < 0)
928 rlen = 0;
929
930 /* Copy the rest from the write-buffer */
931 memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
932 spin_unlock(&wbuf->lock);
933
934 if (rlen > 0) {
935 /* Read everything that goes before write-buffer */
936 err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0);
937 if (err && err != -EBADMSG)
938 return err;
939 }
940
941 if (type != ch->node_type) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200942 ubifs_err(c, "bad node type (%d but expected %d)",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200943 ch->node_type, type);
944 goto out;
945 }
946
947 err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
948 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200949 ubifs_err(c, "expected node type %d", type);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200950 return err;
951 }
952
953 rlen = le32_to_cpu(ch->len);
954 if (rlen != len) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200955 ubifs_err(c, "bad node length %d, expected %d", rlen, len);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200956 goto out;
957 }
958
959 return 0;
960
961out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200962 ubifs_err(c, "bad node at LEB %d:%d", lnum, offs);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200963 ubifs_dump_node(c, buf);
964 dump_stack();
965 return -EINVAL;
966}
967
968/**
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100969 * ubifs_read_node - read node.
970 * @c: UBIFS file-system description object
971 * @buf: buffer to read to
972 * @type: node type
973 * @len: node length (not aligned)
974 * @lnum: logical eraseblock number
975 * @offs: offset within the logical eraseblock
976 *
977 * This function reads a node of known type and and length, checks it and
978 * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
979 * and a negative error code in case of failure.
980 */
981int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
982 int lnum, int offs)
983{
984 int err, l;
985 struct ubifs_ch *ch = buf;
986
987 dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
988 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
989 ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size);
990 ubifs_assert(!(offs & 7) && offs < c->leb_size);
991 ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
992
Heiko Schocherff94bc42014-06-24 10:10:04 +0200993 err = ubifs_leb_read(c, lnum, buf, offs, len, 0);
994 if (err && err != -EBADMSG)
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100995 return err;
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100996
997 if (type != ch->node_type) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200998 ubifs_errc(c, "bad node type (%d but expected %d)",
999 ch->node_type, type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001000 goto out;
1001 }
1002
1003 err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
1004 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001005 ubifs_errc(c, "expected node type %d", type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001006 return err;
1007 }
1008
1009 l = le32_to_cpu(ch->len);
1010 if (l != len) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001011 ubifs_errc(c, "bad node length %d, expected %d", l, len);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001012 goto out;
1013 }
1014
1015 return 0;
1016
1017out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001018 ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum,
1019 offs, ubi_is_mapped(c->ubi, lnum));
1020 if (!c->probing) {
1021 ubifs_dump_node(c, buf);
1022 dump_stack();
1023 }
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001024 return -EINVAL;
1025}
Heiko Schocherff94bc42014-06-24 10:10:04 +02001026
1027/**
1028 * ubifs_wbuf_init - initialize write-buffer.
1029 * @c: UBIFS file-system description object
1030 * @wbuf: write-buffer to initialize
1031 *
1032 * This function initializes write-buffer. Returns zero in case of success
1033 * %-ENOMEM in case of failure.
1034 */
1035int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf)
1036{
1037 size_t size;
1038
1039 wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL);
1040 if (!wbuf->buf)
1041 return -ENOMEM;
1042
1043 size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t);
1044 wbuf->inodes = kmalloc(size, GFP_KERNEL);
1045 if (!wbuf->inodes) {
1046 kfree(wbuf->buf);
1047 wbuf->buf = NULL;
1048 return -ENOMEM;
1049 }
1050
1051 wbuf->used = 0;
1052 wbuf->lnum = wbuf->offs = -1;
1053 /*
1054 * If the LEB starts at the max. write size aligned address, then
1055 * write-buffer size has to be set to @c->max_write_size. Otherwise,
1056 * set it to something smaller so that it ends at the closest max.
1057 * write size boundary.
1058 */
1059 size = c->max_write_size - (c->leb_start % c->max_write_size);
1060 wbuf->avail = wbuf->size = size;
1061 wbuf->sync_callback = NULL;
1062 mutex_init(&wbuf->io_mutex);
1063 spin_lock_init(&wbuf->lock);
1064 wbuf->c = c;
1065 wbuf->next_ino = 0;
1066
1067#ifndef __UBOOT__
1068 hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1069 wbuf->timer.function = wbuf_timer_callback_nolock;
1070 wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0);
1071 wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT;
1072 wbuf->delta *= 1000000000ULL;
1073 ubifs_assert(wbuf->delta <= ULONG_MAX);
1074#endif
1075 return 0;
1076}
1077
1078/**
1079 * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
1080 * @wbuf: the write-buffer where to add
1081 * @inum: the inode number
1082 *
1083 * This function adds an inode number to the inode array of the write-buffer.
1084 */
1085void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum)
1086{
1087 if (!wbuf->buf)
1088 /* NOR flash or something similar */
1089 return;
1090
1091 spin_lock(&wbuf->lock);
1092 if (wbuf->used)
1093 wbuf->inodes[wbuf->next_ino++] = inum;
1094 spin_unlock(&wbuf->lock);
1095}
1096
1097/**
1098 * wbuf_has_ino - returns if the wbuf contains data from the inode.
1099 * @wbuf: the write-buffer
1100 * @inum: the inode number
1101 *
1102 * This function returns with %1 if the write-buffer contains some data from the
1103 * given inode otherwise it returns with %0.
1104 */
1105static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum)
1106{
1107 int i, ret = 0;
1108
1109 spin_lock(&wbuf->lock);
1110 for (i = 0; i < wbuf->next_ino; i++)
1111 if (inum == wbuf->inodes[i]) {
1112 ret = 1;
1113 break;
1114 }
1115 spin_unlock(&wbuf->lock);
1116
1117 return ret;
1118}
1119
1120/**
1121 * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
1122 * @c: UBIFS file-system description object
1123 * @inode: inode to synchronize
1124 *
1125 * This function synchronizes write-buffers which contain nodes belonging to
1126 * @inode. Returns zero in case of success and a negative error code in case of
1127 * failure.
1128 */
1129int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode)
1130{
1131 int i, err = 0;
1132
1133 for (i = 0; i < c->jhead_cnt; i++) {
1134 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
1135
1136 if (i == GCHD)
1137 /*
1138 * GC head is special, do not look at it. Even if the
1139 * head contains something related to this inode, it is
1140 * a _copy_ of corresponding on-flash node which sits
1141 * somewhere else.
1142 */
1143 continue;
1144
1145 if (!wbuf_has_ino(wbuf, inode->i_ino))
1146 continue;
1147
1148 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
1149 if (wbuf_has_ino(wbuf, inode->i_ino))
1150 err = ubifs_wbuf_sync_nolock(wbuf);
1151 mutex_unlock(&wbuf->io_mutex);
1152
1153 if (err) {
1154 ubifs_ro_mode(c, err);
1155 return err;
1156 }
1157 }
1158 return 0;
1159}