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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__
Simon Glass691d7192020-05-10 11:40:02 -060062#include <init.h>
Simon Glassf7ae49f2020-05-10 11:40:05 -060063#include <log.h>
Simon Glass61b29b82020-02-03 07:36:15 -070064#include <dm/devres.h>
Heiko Schocherff94bc42014-06-24 10:10:04 +020065#include <linux/crc32.h>
66#include <linux/slab.h>
Simon Glass3db71102019-11-14 12:57:16 -070067#include <u-boot/crc.h>
Heiko Schocherff94bc42014-06-24 10:10:04 +020068#else
69#include <linux/compat.h>
70#include <linux/err.h>
71#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +010072#include "ubifs.h"
73
74/**
75 * ubifs_ro_mode - switch UBIFS to read read-only mode.
76 * @c: UBIFS file-system description object
77 * @err: error code which is the reason of switching to R/O mode
78 */
79void ubifs_ro_mode(struct ubifs_info *c, int err)
80{
Heiko Schocherff94bc42014-06-24 10:10:04 +020081 if (!c->ro_error) {
82 c->ro_error = 1;
Stefan Roese9eefe2a2009-03-19 15:35:05 +010083 c->no_chk_data_crc = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +020084 c->vfs_sb->s_flags |= MS_RDONLY;
Heiko Schocher0195a7b2015-10-22 06:19:21 +020085 ubifs_warn(c, "switched to read-only mode, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +020086 dump_stack();
Stefan Roese9eefe2a2009-03-19 15:35:05 +010087 }
88}
89
Heiko Schocherff94bc42014-06-24 10:10:04 +020090/*
91 * Below are simple wrappers over UBI I/O functions which include some
92 * additional checks and UBIFS debugging stuff. See corresponding UBI function
93 * for more information.
94 */
95
96int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs,
97 int len, int even_ebadmsg)
98{
99 int err;
100
101 err = ubi_read(c->ubi, lnum, buf, offs, len);
102 /*
103 * In case of %-EBADMSG print the error message only if the
104 * @even_ebadmsg is true.
105 */
106 if (err && (err != -EBADMSG || even_ebadmsg)) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200107 ubifs_err(c, "reading %d bytes from LEB %d:%d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200108 len, lnum, offs, err);
109 dump_stack();
110 }
111 return err;
112}
113
114int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs,
115 int len)
116{
Heinrich Schuchardt81f56272020-12-25 15:19:39 +0100117 int err = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200118
119 ubifs_assert(!c->ro_media && !c->ro_mount);
120 if (c->ro_error)
121 return -EROFS;
122 if (!dbg_is_tst_rcvry(c))
123 err = ubi_leb_write(c->ubi, lnum, buf, offs, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200124#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200125 else
126 err = dbg_leb_write(c, lnum, buf, offs, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200127#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200128 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200129 ubifs_err(c, "writing %d bytes to LEB %d:%d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200130 len, lnum, offs, err);
131 ubifs_ro_mode(c, err);
132 dump_stack();
133 }
134 return err;
135}
136
137int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len)
138{
Heinrich Schuchardt81f56272020-12-25 15:19:39 +0100139 int err = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200140
141 ubifs_assert(!c->ro_media && !c->ro_mount);
142 if (c->ro_error)
143 return -EROFS;
144 if (!dbg_is_tst_rcvry(c))
145 err = ubi_leb_change(c->ubi, lnum, buf, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200146#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200147 else
148 err = dbg_leb_change(c, lnum, buf, len);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200149#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200150 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200151 ubifs_err(c, "changing %d bytes in LEB %d failed, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200152 len, lnum, err);
153 ubifs_ro_mode(c, err);
154 dump_stack();
155 }
156 return err;
157}
158
159int ubifs_leb_unmap(struct ubifs_info *c, int lnum)
160{
Heinrich Schuchardt81f56272020-12-25 15:19:39 +0100161 int err = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200162
163 ubifs_assert(!c->ro_media && !c->ro_mount);
164 if (c->ro_error)
165 return -EROFS;
166 if (!dbg_is_tst_rcvry(c))
167 err = ubi_leb_unmap(c->ubi, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200168#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200169 else
170 err = dbg_leb_unmap(c, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200171#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200172 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200173 ubifs_err(c, "unmap LEB %d failed, error %d", lnum, err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200174 ubifs_ro_mode(c, err);
175 dump_stack();
176 }
177 return err;
178}
179
180int ubifs_leb_map(struct ubifs_info *c, int lnum)
181{
Heinrich Schuchardt81f56272020-12-25 15:19:39 +0100182 int err = 0;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200183
184 ubifs_assert(!c->ro_media && !c->ro_mount);
185 if (c->ro_error)
186 return -EROFS;
187 if (!dbg_is_tst_rcvry(c))
188 err = ubi_leb_map(c->ubi, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200189#ifndef __UBOOT__
Heiko Schocherff94bc42014-06-24 10:10:04 +0200190 else
191 err = dbg_leb_map(c, lnum);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200192#endif
Heiko Schocherff94bc42014-06-24 10:10:04 +0200193 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200194 ubifs_err(c, "mapping LEB %d failed, error %d", lnum, err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200195 ubifs_ro_mode(c, err);
196 dump_stack();
197 }
198 return err;
199}
200
201int ubifs_is_mapped(const struct ubifs_info *c, int lnum)
202{
203 int err;
204
205 err = ubi_is_mapped(c->ubi, lnum);
206 if (err < 0) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200207 ubifs_err(c, "ubi_is_mapped failed for LEB %d, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200208 lnum, err);
209 dump_stack();
210 }
211 return err;
212}
213
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100214/**
215 * ubifs_check_node - check node.
216 * @c: UBIFS file-system description object
217 * @buf: node to check
218 * @lnum: logical eraseblock number
219 * @offs: offset within the logical eraseblock
220 * @quiet: print no messages
221 * @must_chk_crc: indicates whether to always check the CRC
222 *
223 * This function checks node magic number and CRC checksum. This function also
224 * validates node length to prevent UBIFS from becoming crazy when an attacker
225 * feeds it a file-system image with incorrect nodes. For example, too large
226 * node length in the common header could cause UBIFS to read memory outside of
227 * allocated buffer when checking the CRC checksum.
228 *
229 * This function may skip data nodes CRC checking if @c->no_chk_data_crc is
230 * true, which is controlled by corresponding UBIFS mount option. However, if
231 * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is
Heiko Schocherff94bc42014-06-24 10:10:04 +0200232 * checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are
233 * mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC
234 * is checked. This is because during mounting or re-mounting from R/O mode to
235 * R/W mode we may read journal nodes (when replying the journal or doing the
236 * recovery) and the journal nodes may potentially be corrupted, so checking is
237 * required.
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100238 *
239 * This function returns zero in case of success and %-EUCLEAN in case of bad
240 * CRC or magic.
241 */
242int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
243 int offs, int quiet, int must_chk_crc)
244{
245 int err = -EINVAL, type, node_len;
246 uint32_t crc, node_crc, magic;
247 const struct ubifs_ch *ch = buf;
248
249 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
250 ubifs_assert(!(offs & 7) && offs < c->leb_size);
251
252 magic = le32_to_cpu(ch->magic);
253 if (magic != UBIFS_NODE_MAGIC) {
254 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200255 ubifs_err(c, "bad magic %#08x, expected %#08x",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100256 magic, UBIFS_NODE_MAGIC);
257 err = -EUCLEAN;
258 goto out;
259 }
260
261 type = ch->node_type;
262 if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) {
263 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200264 ubifs_err(c, "bad node type %d", type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100265 goto out;
266 }
267
268 node_len = le32_to_cpu(ch->len);
269 if (node_len + offs > c->leb_size)
270 goto out_len;
271
272 if (c->ranges[type].max_len == 0) {
273 if (node_len != c->ranges[type].len)
274 goto out_len;
275 } else if (node_len < c->ranges[type].min_len ||
276 node_len > c->ranges[type].max_len)
277 goto out_len;
278
Heiko Schocherff94bc42014-06-24 10:10:04 +0200279 if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting &&
280 !c->remounting_rw && c->no_chk_data_crc)
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100281 return 0;
282
283 crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
284 node_crc = le32_to_cpu(ch->crc);
285 if (crc != node_crc) {
286 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200287 ubifs_err(c, "bad CRC: calculated %#08x, read %#08x",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100288 crc, node_crc);
289 err = -EUCLEAN;
290 goto out;
291 }
292
293 return 0;
294
295out_len:
296 if (!quiet)
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200297 ubifs_err(c, "bad node length %d", node_len);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100298out:
299 if (!quiet) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200300 ubifs_err(c, "bad node at LEB %d:%d", lnum, offs);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200301 ubifs_dump_node(c, buf);
302 dump_stack();
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100303 }
304 return err;
305}
306
307/**
308 * ubifs_pad - pad flash space.
309 * @c: UBIFS file-system description object
310 * @buf: buffer to put padding to
311 * @pad: how many bytes to pad
312 *
313 * The flash media obliges us to write only in chunks of %c->min_io_size and
314 * when we have to write less data we add padding node to the write-buffer and
315 * pad it to the next minimal I/O unit's boundary. Padding nodes help when the
316 * media is being scanned. If the amount of wasted space is not enough to fit a
317 * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes
318 * pattern (%UBIFS_PADDING_BYTE).
319 *
320 * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
321 * used.
322 */
323void ubifs_pad(const struct ubifs_info *c, void *buf, int pad)
324{
325 uint32_t crc;
326
327 ubifs_assert(pad >= 0 && !(pad & 7));
328
329 if (pad >= UBIFS_PAD_NODE_SZ) {
330 struct ubifs_ch *ch = buf;
331 struct ubifs_pad_node *pad_node = buf;
332
333 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
334 ch->node_type = UBIFS_PAD_NODE;
335 ch->group_type = UBIFS_NO_NODE_GROUP;
336 ch->padding[0] = ch->padding[1] = 0;
337 ch->sqnum = 0;
338 ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ);
339 pad -= UBIFS_PAD_NODE_SZ;
340 pad_node->pad_len = cpu_to_le32(pad);
341 crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8);
342 ch->crc = cpu_to_le32(crc);
343 memset(buf + UBIFS_PAD_NODE_SZ, 0, pad);
344 } else if (pad > 0)
345 /* Too little space, padding node won't fit */
346 memset(buf, UBIFS_PADDING_BYTE, pad);
347}
348
349/**
350 * next_sqnum - get next sequence number.
351 * @c: UBIFS file-system description object
352 */
353static unsigned long long next_sqnum(struct ubifs_info *c)
354{
355 unsigned long long sqnum;
356
357 spin_lock(&c->cnt_lock);
358 sqnum = ++c->max_sqnum;
359 spin_unlock(&c->cnt_lock);
360
361 if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) {
362 if (sqnum >= SQNUM_WATERMARK) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200363 ubifs_err(c, "sequence number overflow %llu, end of life",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100364 sqnum);
365 ubifs_ro_mode(c, -EINVAL);
366 }
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200367 ubifs_warn(c, "running out of sequence numbers, end of life soon");
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100368 }
369
370 return sqnum;
371}
372
373/**
374 * ubifs_prepare_node - prepare node to be written to flash.
375 * @c: UBIFS file-system description object
376 * @node: the node to pad
377 * @len: node length
378 * @pad: if the buffer has to be padded
379 *
380 * This function prepares node at @node to be written to the media - it
381 * calculates node CRC, fills the common header, and adds proper padding up to
382 * the next minimum I/O unit if @pad is not zero.
383 */
384void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
385{
386 uint32_t crc;
387 struct ubifs_ch *ch = node;
388 unsigned long long sqnum = next_sqnum(c);
389
390 ubifs_assert(len >= UBIFS_CH_SZ);
391
392 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
393 ch->len = cpu_to_le32(len);
394 ch->group_type = UBIFS_NO_NODE_GROUP;
395 ch->sqnum = cpu_to_le64(sqnum);
396 ch->padding[0] = ch->padding[1] = 0;
397 crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
398 ch->crc = cpu_to_le32(crc);
399
400 if (pad) {
401 len = ALIGN(len, 8);
402 pad = ALIGN(len, c->min_io_size) - len;
403 ubifs_pad(c, node + len, pad);
404 }
405}
406
407/**
Heiko Schocherff94bc42014-06-24 10:10:04 +0200408 * ubifs_prep_grp_node - prepare node of a group to be written to flash.
409 * @c: UBIFS file-system description object
410 * @node: the node to pad
411 * @len: node length
412 * @last: indicates the last node of the group
413 *
414 * This function prepares node at @node to be written to the media - it
415 * calculates node CRC and fills the common header.
416 */
417void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last)
418{
419 uint32_t crc;
420 struct ubifs_ch *ch = node;
421 unsigned long long sqnum = next_sqnum(c);
422
423 ubifs_assert(len >= UBIFS_CH_SZ);
424
425 ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
426 ch->len = cpu_to_le32(len);
427 if (last)
428 ch->group_type = UBIFS_LAST_OF_NODE_GROUP;
429 else
430 ch->group_type = UBIFS_IN_NODE_GROUP;
431 ch->sqnum = cpu_to_le64(sqnum);
432 ch->padding[0] = ch->padding[1] = 0;
433 crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
434 ch->crc = cpu_to_le32(crc);
435}
436
437#ifndef __UBOOT__
438/**
439 * wbuf_timer_callback - write-buffer timer callback function.
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200440 * @timer: timer data (write-buffer descriptor)
Heiko Schocherff94bc42014-06-24 10:10:04 +0200441 *
442 * This function is called when the write-buffer timer expires.
443 */
444static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer)
445{
446 struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer);
447
448 dbg_io("jhead %s", dbg_jhead(wbuf->jhead));
449 wbuf->need_sync = 1;
450 wbuf->c->need_wbuf_sync = 1;
451 ubifs_wake_up_bgt(wbuf->c);
452 return HRTIMER_NORESTART;
453}
454
455/**
456 * new_wbuf_timer - start new write-buffer timer.
457 * @wbuf: write-buffer descriptor
458 */
459static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
460{
461 ubifs_assert(!hrtimer_active(&wbuf->timer));
462
463 if (wbuf->no_timer)
464 return;
465 dbg_io("set timer for jhead %s, %llu-%llu millisecs",
466 dbg_jhead(wbuf->jhead),
467 div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC),
468 div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta,
469 USEC_PER_SEC));
470 hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta,
471 HRTIMER_MODE_REL);
472}
473#endif
474
475/**
476 * cancel_wbuf_timer - cancel write-buffer timer.
477 * @wbuf: write-buffer descriptor
478 */
479static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
480{
481 if (wbuf->no_timer)
482 return;
483 wbuf->need_sync = 0;
484#ifndef __UBOOT__
485 hrtimer_cancel(&wbuf->timer);
486#endif
487}
488
489/**
490 * ubifs_wbuf_sync_nolock - synchronize write-buffer.
491 * @wbuf: write-buffer to synchronize
492 *
493 * This function synchronizes write-buffer @buf and returns zero in case of
494 * success or a negative error code in case of failure.
495 *
496 * Note, although write-buffers are of @c->max_write_size, this function does
497 * not necessarily writes all @c->max_write_size bytes to the flash. Instead,
498 * if the write-buffer is only partially filled with data, only the used part
499 * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized.
500 * This way we waste less space.
501 */
502int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
503{
504 struct ubifs_info *c = wbuf->c;
505 int err, dirt, sync_len;
506
507 cancel_wbuf_timer_nolock(wbuf);
508 if (!wbuf->used || wbuf->lnum == -1)
509 /* Write-buffer is empty or not seeked */
510 return 0;
511
512 dbg_io("LEB %d:%d, %d bytes, jhead %s",
513 wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead));
514 ubifs_assert(!(wbuf->avail & 7));
515 ubifs_assert(wbuf->offs + wbuf->size <= c->leb_size);
516 ubifs_assert(wbuf->size >= c->min_io_size);
517 ubifs_assert(wbuf->size <= c->max_write_size);
518 ubifs_assert(wbuf->size % c->min_io_size == 0);
519 ubifs_assert(!c->ro_media && !c->ro_mount);
520 if (c->leb_size - wbuf->offs >= c->max_write_size)
521 ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size));
522
523 if (c->ro_error)
524 return -EROFS;
525
526 /*
527 * Do not write whole write buffer but write only the minimum necessary
528 * amount of min. I/O units.
529 */
530 sync_len = ALIGN(wbuf->used, c->min_io_size);
531 dirt = sync_len - wbuf->used;
532 if (dirt)
533 ubifs_pad(c, wbuf->buf + wbuf->used, dirt);
534 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len);
535 if (err)
536 return err;
537
538 spin_lock(&wbuf->lock);
539 wbuf->offs += sync_len;
540 /*
541 * Now @wbuf->offs is not necessarily aligned to @c->max_write_size.
542 * But our goal is to optimize writes and make sure we write in
543 * @c->max_write_size chunks and to @c->max_write_size-aligned offset.
544 * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make
545 * sure that @wbuf->offs + @wbuf->size is aligned to
546 * @c->max_write_size. This way we make sure that after next
547 * write-buffer flush we are again at the optimal offset (aligned to
548 * @c->max_write_size).
549 */
550 if (c->leb_size - wbuf->offs < c->max_write_size)
551 wbuf->size = c->leb_size - wbuf->offs;
552 else if (wbuf->offs & (c->max_write_size - 1))
553 wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs;
554 else
555 wbuf->size = c->max_write_size;
556 wbuf->avail = wbuf->size;
557 wbuf->used = 0;
558 wbuf->next_ino = 0;
559 spin_unlock(&wbuf->lock);
560
561 if (wbuf->sync_callback)
562 err = wbuf->sync_callback(c, wbuf->lnum,
563 c->leb_size - wbuf->offs, dirt);
564 return err;
565}
566
567/**
568 * ubifs_wbuf_seek_nolock - seek write-buffer.
569 * @wbuf: write-buffer
570 * @lnum: logical eraseblock number to seek to
571 * @offs: logical eraseblock offset to seek to
572 *
573 * This function targets the write-buffer to logical eraseblock @lnum:@offs.
574 * The write-buffer has to be empty. Returns zero in case of success and a
575 * negative error code in case of failure.
576 */
577int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs)
578{
579 const struct ubifs_info *c = wbuf->c;
580
581 dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead));
582 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt);
583 ubifs_assert(offs >= 0 && offs <= c->leb_size);
584 ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7));
585 ubifs_assert(lnum != wbuf->lnum);
586 ubifs_assert(wbuf->used == 0);
587
588 spin_lock(&wbuf->lock);
589 wbuf->lnum = lnum;
590 wbuf->offs = offs;
591 if (c->leb_size - wbuf->offs < c->max_write_size)
592 wbuf->size = c->leb_size - wbuf->offs;
593 else if (wbuf->offs & (c->max_write_size - 1))
594 wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs;
595 else
596 wbuf->size = c->max_write_size;
597 wbuf->avail = wbuf->size;
598 wbuf->used = 0;
599 spin_unlock(&wbuf->lock);
600
601 return 0;
602}
603
604#ifndef __UBOOT__
605/**
606 * ubifs_bg_wbufs_sync - synchronize write-buffers.
607 * @c: UBIFS file-system description object
608 *
609 * This function is called by background thread to synchronize write-buffers.
610 * Returns zero in case of success and a negative error code in case of
611 * failure.
612 */
613int ubifs_bg_wbufs_sync(struct ubifs_info *c)
614{
615 int err, i;
616
617 ubifs_assert(!c->ro_media && !c->ro_mount);
618 if (!c->need_wbuf_sync)
619 return 0;
620 c->need_wbuf_sync = 0;
621
622 if (c->ro_error) {
623 err = -EROFS;
624 goto out_timers;
625 }
626
627 dbg_io("synchronize");
628 for (i = 0; i < c->jhead_cnt; i++) {
629 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
630
631 cond_resched();
632
633 /*
634 * If the mutex is locked then wbuf is being changed, so
635 * synchronization is not necessary.
636 */
637 if (mutex_is_locked(&wbuf->io_mutex))
638 continue;
639
640 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
641 if (!wbuf->need_sync) {
642 mutex_unlock(&wbuf->io_mutex);
643 continue;
644 }
645
646 err = ubifs_wbuf_sync_nolock(wbuf);
647 mutex_unlock(&wbuf->io_mutex);
648 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200649 ubifs_err(c, "cannot sync write-buffer, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200650 ubifs_ro_mode(c, err);
651 goto out_timers;
652 }
653 }
654
655 return 0;
656
657out_timers:
658 /* Cancel all timers to prevent repeated errors */
659 for (i = 0; i < c->jhead_cnt; i++) {
660 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
661
662 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
663 cancel_wbuf_timer_nolock(wbuf);
664 mutex_unlock(&wbuf->io_mutex);
665 }
666 return err;
667}
668
669/**
670 * ubifs_wbuf_write_nolock - write data to flash via write-buffer.
671 * @wbuf: write-buffer
672 * @buf: node to write
673 * @len: node length
674 *
675 * This function writes data to flash via write-buffer @wbuf. This means that
676 * the last piece of the node won't reach the flash media immediately if it
677 * does not take whole max. write unit (@c->max_write_size). Instead, the node
678 * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or
679 * because more data are appended to the write-buffer).
680 *
681 * This function returns zero in case of success and a negative error code in
682 * case of failure. If the node cannot be written because there is no more
683 * space in this logical eraseblock, %-ENOSPC is returned.
684 */
685int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
686{
687 struct ubifs_info *c = wbuf->c;
688 int err, written, n, aligned_len = ALIGN(len, 8);
689
690 dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len,
691 dbg_ntype(((struct ubifs_ch *)buf)->node_type),
692 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used);
693 ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt);
694 ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0);
695 ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
696 ubifs_assert(wbuf->avail > 0 && wbuf->avail <= wbuf->size);
697 ubifs_assert(wbuf->size >= c->min_io_size);
698 ubifs_assert(wbuf->size <= c->max_write_size);
699 ubifs_assert(wbuf->size % c->min_io_size == 0);
700 ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
701 ubifs_assert(!c->ro_media && !c->ro_mount);
702 ubifs_assert(!c->space_fixup);
703 if (c->leb_size - wbuf->offs >= c->max_write_size)
704 ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size));
705
706 if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
707 err = -ENOSPC;
708 goto out;
709 }
710
711 cancel_wbuf_timer_nolock(wbuf);
712
713 if (c->ro_error)
714 return -EROFS;
715
716 if (aligned_len <= wbuf->avail) {
717 /*
718 * The node is not very large and fits entirely within
719 * write-buffer.
720 */
721 memcpy(wbuf->buf + wbuf->used, buf, len);
722
723 if (aligned_len == wbuf->avail) {
724 dbg_io("flush jhead %s wbuf to LEB %d:%d",
725 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
726 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf,
727 wbuf->offs, wbuf->size);
728 if (err)
729 goto out;
730
731 spin_lock(&wbuf->lock);
732 wbuf->offs += wbuf->size;
733 if (c->leb_size - wbuf->offs >= c->max_write_size)
734 wbuf->size = c->max_write_size;
735 else
736 wbuf->size = c->leb_size - wbuf->offs;
737 wbuf->avail = wbuf->size;
738 wbuf->used = 0;
739 wbuf->next_ino = 0;
740 spin_unlock(&wbuf->lock);
741 } else {
742 spin_lock(&wbuf->lock);
743 wbuf->avail -= aligned_len;
744 wbuf->used += aligned_len;
745 spin_unlock(&wbuf->lock);
746 }
747
748 goto exit;
749 }
750
751 written = 0;
752
753 if (wbuf->used) {
754 /*
755 * The node is large enough and does not fit entirely within
756 * current available space. We have to fill and flush
757 * write-buffer and switch to the next max. write unit.
758 */
759 dbg_io("flush jhead %s wbuf to LEB %d:%d",
760 dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
761 memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail);
762 err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs,
763 wbuf->size);
764 if (err)
765 goto out;
766
767 wbuf->offs += wbuf->size;
768 len -= wbuf->avail;
769 aligned_len -= wbuf->avail;
770 written += wbuf->avail;
771 } else if (wbuf->offs & (c->max_write_size - 1)) {
772 /*
773 * The write-buffer offset is not aligned to
774 * @c->max_write_size and @wbuf->size is less than
775 * @c->max_write_size. Write @wbuf->size bytes to make sure the
776 * following writes are done in optimal @c->max_write_size
777 * chunks.
778 */
779 dbg_io("write %d bytes to LEB %d:%d",
780 wbuf->size, wbuf->lnum, wbuf->offs);
781 err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs,
782 wbuf->size);
783 if (err)
784 goto out;
785
786 wbuf->offs += wbuf->size;
787 len -= wbuf->size;
788 aligned_len -= wbuf->size;
789 written += wbuf->size;
790 }
791
792 /*
793 * The remaining data may take more whole max. write units, so write the
794 * remains multiple to max. write unit size directly to the flash media.
795 * We align node length to 8-byte boundary because we anyway flash wbuf
796 * if the remaining space is less than 8 bytes.
797 */
798 n = aligned_len >> c->max_write_shift;
799 if (n) {
800 n <<= c->max_write_shift;
801 dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum,
802 wbuf->offs);
803 err = ubifs_leb_write(c, wbuf->lnum, buf + written,
804 wbuf->offs, n);
805 if (err)
806 goto out;
807 wbuf->offs += n;
808 aligned_len -= n;
809 len -= n;
810 written += n;
811 }
812
813 spin_lock(&wbuf->lock);
814 if (aligned_len)
815 /*
816 * And now we have what's left and what does not take whole
817 * max. write unit, so write it to the write-buffer and we are
818 * done.
819 */
820 memcpy(wbuf->buf, buf + written, len);
821
822 if (c->leb_size - wbuf->offs >= c->max_write_size)
823 wbuf->size = c->max_write_size;
824 else
825 wbuf->size = c->leb_size - wbuf->offs;
826 wbuf->avail = wbuf->size - aligned_len;
827 wbuf->used = aligned_len;
828 wbuf->next_ino = 0;
829 spin_unlock(&wbuf->lock);
830
831exit:
832 if (wbuf->sync_callback) {
833 int free = c->leb_size - wbuf->offs - wbuf->used;
834
835 err = wbuf->sync_callback(c, wbuf->lnum, free, 0);
836 if (err)
837 goto out;
838 }
839
840 if (wbuf->used)
841 new_wbuf_timer_nolock(wbuf);
842
843 return 0;
844
845out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200846 ubifs_err(c, "cannot write %d bytes to LEB %d:%d, error %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200847 len, wbuf->lnum, wbuf->offs, err);
848 ubifs_dump_node(c, buf);
849 dump_stack();
850 ubifs_dump_leb(c, wbuf->lnum);
851 return err;
852}
853
854/**
855 * ubifs_write_node - write node to the media.
856 * @c: UBIFS file-system description object
857 * @buf: the node to write
858 * @len: node length
859 * @lnum: logical eraseblock number
860 * @offs: offset within the logical eraseblock
861 *
862 * This function automatically fills node magic number, assigns sequence
863 * number, and calculates node CRC checksum. The length of the @buf buffer has
864 * to be aligned to the minimal I/O unit size. This function automatically
865 * appends padding node and padding bytes if needed. Returns zero in case of
866 * success and a negative error code in case of failure.
867 */
868int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
869 int offs)
870{
871 int err, buf_len = ALIGN(len, c->min_io_size);
872
873 dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
874 lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len,
875 buf_len);
876 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
877 ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);
878 ubifs_assert(!c->ro_media && !c->ro_mount);
879 ubifs_assert(!c->space_fixup);
880
881 if (c->ro_error)
882 return -EROFS;
883
884 ubifs_prepare_node(c, buf, len, 1);
885 err = ubifs_leb_write(c, lnum, buf, offs, buf_len);
886 if (err)
887 ubifs_dump_node(c, buf);
888
889 return err;
890}
891#endif
892
893/**
894 * ubifs_read_node_wbuf - read node from the media or write-buffer.
895 * @wbuf: wbuf to check for un-written data
896 * @buf: buffer to read to
897 * @type: node type
898 * @len: node length
899 * @lnum: logical eraseblock number
900 * @offs: offset within the logical eraseblock
901 *
902 * This function reads a node of known type and length, checks it and stores
903 * in @buf. If the node partially or fully sits in the write-buffer, this
904 * function takes data from the buffer, otherwise it reads the flash media.
905 * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
906 * error code in case of failure.
907 */
908int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
909 int lnum, int offs)
910{
911 const struct ubifs_info *c = wbuf->c;
912 int err, rlen, overlap;
913 struct ubifs_ch *ch = buf;
914
915 dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs,
916 dbg_ntype(type), len, dbg_jhead(wbuf->jhead));
917 ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
918 ubifs_assert(!(offs & 7) && offs < c->leb_size);
919 ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
920
921 spin_lock(&wbuf->lock);
922 overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
923 if (!overlap) {
924 /* We may safely unlock the write-buffer and read the data */
925 spin_unlock(&wbuf->lock);
926 return ubifs_read_node(c, buf, type, len, lnum, offs);
927 }
928
929 /* Don't read under wbuf */
930 rlen = wbuf->offs - offs;
931 if (rlen < 0)
932 rlen = 0;
933
934 /* Copy the rest from the write-buffer */
935 memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
936 spin_unlock(&wbuf->lock);
937
938 if (rlen > 0) {
939 /* Read everything that goes before write-buffer */
940 err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0);
941 if (err && err != -EBADMSG)
942 return err;
943 }
944
945 if (type != ch->node_type) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200946 ubifs_err(c, "bad node type (%d but expected %d)",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200947 ch->node_type, type);
948 goto out;
949 }
950
951 err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
952 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200953 ubifs_err(c, "expected node type %d", type);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200954 return err;
955 }
956
957 rlen = le32_to_cpu(ch->len);
958 if (rlen != len) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200959 ubifs_err(c, "bad node length %d, expected %d", rlen, len);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200960 goto out;
961 }
962
963 return 0;
964
965out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200966 ubifs_err(c, "bad node at LEB %d:%d", lnum, offs);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200967 ubifs_dump_node(c, buf);
968 dump_stack();
969 return -EINVAL;
970}
971
972/**
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100973 * ubifs_read_node - read node.
974 * @c: UBIFS file-system description object
975 * @buf: buffer to read to
976 * @type: node type
977 * @len: node length (not aligned)
978 * @lnum: logical eraseblock number
979 * @offs: offset within the logical eraseblock
980 *
981 * This function reads a node of known type and and length, checks it and
982 * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
983 * and a negative error code in case of failure.
984 */
985int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
986 int lnum, int offs)
987{
988 int err, l;
989 struct ubifs_ch *ch = buf;
990
991 dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
992 ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
993 ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size);
994 ubifs_assert(!(offs & 7) && offs < c->leb_size);
995 ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
996
Heiko Schocherff94bc42014-06-24 10:10:04 +0200997 err = ubifs_leb_read(c, lnum, buf, offs, len, 0);
998 if (err && err != -EBADMSG)
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100999 return err;
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001000
1001 if (type != ch->node_type) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001002 ubifs_errc(c, "bad node type (%d but expected %d)",
1003 ch->node_type, type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001004 goto out;
1005 }
1006
1007 err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
1008 if (err) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001009 ubifs_errc(c, "expected node type %d", type);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001010 return err;
1011 }
1012
1013 l = le32_to_cpu(ch->len);
1014 if (l != len) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001015 ubifs_errc(c, "bad node length %d, expected %d", l, len);
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001016 goto out;
1017 }
1018
1019 return 0;
1020
1021out:
Heiko Schocher0195a7b2015-10-22 06:19:21 +02001022 ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum,
1023 offs, ubi_is_mapped(c->ubi, lnum));
1024 if (!c->probing) {
1025 ubifs_dump_node(c, buf);
1026 dump_stack();
1027 }
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001028 return -EINVAL;
1029}
Heiko Schocherff94bc42014-06-24 10:10:04 +02001030
1031/**
1032 * ubifs_wbuf_init - initialize write-buffer.
1033 * @c: UBIFS file-system description object
1034 * @wbuf: write-buffer to initialize
1035 *
1036 * This function initializes write-buffer. Returns zero in case of success
1037 * %-ENOMEM in case of failure.
1038 */
1039int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf)
1040{
1041 size_t size;
1042
1043 wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL);
1044 if (!wbuf->buf)
1045 return -ENOMEM;
1046
1047 size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t);
1048 wbuf->inodes = kmalloc(size, GFP_KERNEL);
1049 if (!wbuf->inodes) {
1050 kfree(wbuf->buf);
1051 wbuf->buf = NULL;
1052 return -ENOMEM;
1053 }
1054
1055 wbuf->used = 0;
1056 wbuf->lnum = wbuf->offs = -1;
1057 /*
1058 * If the LEB starts at the max. write size aligned address, then
1059 * write-buffer size has to be set to @c->max_write_size. Otherwise,
1060 * set it to something smaller so that it ends at the closest max.
1061 * write size boundary.
1062 */
1063 size = c->max_write_size - (c->leb_start % c->max_write_size);
1064 wbuf->avail = wbuf->size = size;
1065 wbuf->sync_callback = NULL;
1066 mutex_init(&wbuf->io_mutex);
1067 spin_lock_init(&wbuf->lock);
1068 wbuf->c = c;
1069 wbuf->next_ino = 0;
1070
1071#ifndef __UBOOT__
1072 hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1073 wbuf->timer.function = wbuf_timer_callback_nolock;
1074 wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0);
1075 wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT;
1076 wbuf->delta *= 1000000000ULL;
1077 ubifs_assert(wbuf->delta <= ULONG_MAX);
1078#endif
1079 return 0;
1080}
1081
1082/**
1083 * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
1084 * @wbuf: the write-buffer where to add
1085 * @inum: the inode number
1086 *
1087 * This function adds an inode number to the inode array of the write-buffer.
1088 */
1089void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum)
1090{
1091 if (!wbuf->buf)
1092 /* NOR flash or something similar */
1093 return;
1094
1095 spin_lock(&wbuf->lock);
1096 if (wbuf->used)
1097 wbuf->inodes[wbuf->next_ino++] = inum;
1098 spin_unlock(&wbuf->lock);
1099}
1100
1101/**
1102 * wbuf_has_ino - returns if the wbuf contains data from the inode.
1103 * @wbuf: the write-buffer
1104 * @inum: the inode number
1105 *
1106 * This function returns with %1 if the write-buffer contains some data from the
1107 * given inode otherwise it returns with %0.
1108 */
1109static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum)
1110{
1111 int i, ret = 0;
1112
1113 spin_lock(&wbuf->lock);
1114 for (i = 0; i < wbuf->next_ino; i++)
1115 if (inum == wbuf->inodes[i]) {
1116 ret = 1;
1117 break;
1118 }
1119 spin_unlock(&wbuf->lock);
1120
1121 return ret;
1122}
1123
1124/**
1125 * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
1126 * @c: UBIFS file-system description object
1127 * @inode: inode to synchronize
1128 *
1129 * This function synchronizes write-buffers which contain nodes belonging to
1130 * @inode. Returns zero in case of success and a negative error code in case of
1131 * failure.
1132 */
1133int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode)
1134{
1135 int i, err = 0;
1136
1137 for (i = 0; i < c->jhead_cnt; i++) {
1138 struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
1139
1140 if (i == GCHD)
1141 /*
1142 * GC head is special, do not look at it. Even if the
1143 * head contains something related to this inode, it is
1144 * a _copy_ of corresponding on-flash node which sits
1145 * somewhere else.
1146 */
1147 continue;
1148
1149 if (!wbuf_has_ino(wbuf, inode->i_ino))
1150 continue;
1151
1152 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
1153 if (wbuf_has_ino(wbuf, inode->i_ino))
1154 err = ubifs_wbuf_sync_nolock(wbuf);
1155 mutex_unlock(&wbuf->io_mutex);
1156
1157 if (err) {
1158 ubifs_ro_mode(c, err);
1159 return err;
1160 }
1161 }
1162 return 0;
1163}