2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 * Copyright (C) 2006, 2007 University of Szeged, Hungary
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc., 51
18 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Authors: Artem Bityutskiy (Битюцкий Артём)
26 * This file implements UBIFS I/O subsystem which provides various I/O-related
27 * helper functions (reading/writing/checking/validating nodes) and implements
28 * write-buffering support. Write buffers help to save space which otherwise
29 * would have been wasted for padding to the nearest minimal I/O unit boundary.
30 * Instead, data first goes to the write-buffer and is flushed when the
31 * buffer is full or when it is not used for some time (by timer). This is
32 * similar to the mechanism is used by JFFS2.
34 * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by
35 * mutexes defined inside these objects. Since sometimes upper-level code
36 * has to lock the write-buffer (e.g. journal space reservation code), many
37 * functions related to write-buffers have "nolock" suffix which means that the
38 * caller has to lock the write-buffer before calling this function.
40 * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not
41 * aligned, UBIFS starts the next node from the aligned address, and the padded
42 * bytes may contain any rubbish. In other words, UBIFS does not put padding
43 * bytes in those small gaps. Common headers of nodes store real node lengths,
44 * not aligned lengths. Indexing nodes also store real lengths in branches.
46 * UBIFS uses padding when it pads to the next min. I/O unit. In this case it
47 * uses padding nodes or padding bytes, if the padding node does not fit.
49 * All UBIFS nodes are protected by CRC checksums and UBIFS checks all nodes
50 * every time they are read from the flash media.
53 #include <linux/crc32.h>
54 #include <linux/slab.h>
58 * ubifs_ro_mode - switch UBIFS to read read-only mode.
59 * @c: UBIFS file-system description object
60 * @err: error code which is the reason of switching to R/O mode
62 void ubifs_ro_mode(struct ubifs_info
*c
, int err
)
66 c
->no_chk_data_crc
= 0;
67 ubifs_warn("switched to read-only mode, error %d", err
);
73 * ubifs_check_node - check node.
74 * @c: UBIFS file-system description object
76 * @lnum: logical eraseblock number
77 * @offs: offset within the logical eraseblock
78 * @quiet: print no messages
79 * @must_chk_crc: indicates whether to always check the CRC
81 * This function checks node magic number and CRC checksum. This function also
82 * validates node length to prevent UBIFS from becoming crazy when an attacker
83 * feeds it a file-system image with incorrect nodes. For example, too large
84 * node length in the common header could cause UBIFS to read memory outside of
85 * allocated buffer when checking the CRC checksum.
87 * This function may skip data nodes CRC checking if @c->no_chk_data_crc is
88 * true, which is controlled by corresponding UBIFS mount option. However, if
89 * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is
90 * checked. Similarly, if @c->always_chk_crc is true, @c->no_chk_data_crc is
91 * ignored and CRC is checked.
93 * This function returns zero in case of success and %-EUCLEAN in case of bad
96 int ubifs_check_node(const struct ubifs_info
*c
, const void *buf
, int lnum
,
97 int offs
, int quiet
, int must_chk_crc
)
99 int err
= -EINVAL
, type
, node_len
;
100 uint32_t crc
, node_crc
, magic
;
101 const struct ubifs_ch
*ch
= buf
;
103 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
104 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
106 magic
= le32_to_cpu(ch
->magic
);
107 if (magic
!= UBIFS_NODE_MAGIC
) {
109 ubifs_err("bad magic %#08x, expected %#08x",
110 magic
, UBIFS_NODE_MAGIC
);
115 type
= ch
->node_type
;
116 if (type
< 0 || type
>= UBIFS_NODE_TYPES_CNT
) {
118 ubifs_err("bad node type %d", type
);
122 node_len
= le32_to_cpu(ch
->len
);
123 if (node_len
+ offs
> c
->leb_size
)
126 if (c
->ranges
[type
].max_len
== 0) {
127 if (node_len
!= c
->ranges
[type
].len
)
129 } else if (node_len
< c
->ranges
[type
].min_len
||
130 node_len
> c
->ranges
[type
].max_len
)
133 if (!must_chk_crc
&& type
== UBIFS_DATA_NODE
&& !c
->always_chk_crc
&&
137 crc
= crc32(UBIFS_CRC32_INIT
, buf
+ 8, node_len
- 8);
138 node_crc
= le32_to_cpu(ch
->crc
);
139 if (crc
!= node_crc
) {
141 ubifs_err("bad CRC: calculated %#08x, read %#08x",
151 ubifs_err("bad node length %d", node_len
);
154 ubifs_err("bad node at LEB %d:%d", lnum
, offs
);
155 dbg_dump_node(c
, buf
);
162 * ubifs_pad - pad flash space.
163 * @c: UBIFS file-system description object
164 * @buf: buffer to put padding to
165 * @pad: how many bytes to pad
167 * The flash media obliges us to write only in chunks of %c->min_io_size and
168 * when we have to write less data we add padding node to the write-buffer and
169 * pad it to the next minimal I/O unit's boundary. Padding nodes help when the
170 * media is being scanned. If the amount of wasted space is not enough to fit a
171 * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes
172 * pattern (%UBIFS_PADDING_BYTE).
174 * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
177 void ubifs_pad(const struct ubifs_info
*c
, void *buf
, int pad
)
181 ubifs_assert(pad
>= 0 && !(pad
& 7));
183 if (pad
>= UBIFS_PAD_NODE_SZ
) {
184 struct ubifs_ch
*ch
= buf
;
185 struct ubifs_pad_node
*pad_node
= buf
;
187 ch
->magic
= cpu_to_le32(UBIFS_NODE_MAGIC
);
188 ch
->node_type
= UBIFS_PAD_NODE
;
189 ch
->group_type
= UBIFS_NO_NODE_GROUP
;
190 ch
->padding
[0] = ch
->padding
[1] = 0;
192 ch
->len
= cpu_to_le32(UBIFS_PAD_NODE_SZ
);
193 pad
-= UBIFS_PAD_NODE_SZ
;
194 pad_node
->pad_len
= cpu_to_le32(pad
);
195 crc
= crc32(UBIFS_CRC32_INIT
, buf
+ 8, UBIFS_PAD_NODE_SZ
- 8);
196 ch
->crc
= cpu_to_le32(crc
);
197 memset(buf
+ UBIFS_PAD_NODE_SZ
, 0, pad
);
199 /* Too little space, padding node won't fit */
200 memset(buf
, UBIFS_PADDING_BYTE
, pad
);
204 * next_sqnum - get next sequence number.
205 * @c: UBIFS file-system description object
207 static unsigned long long next_sqnum(struct ubifs_info
*c
)
209 unsigned long long sqnum
;
211 spin_lock(&c
->cnt_lock
);
212 sqnum
= ++c
->max_sqnum
;
213 spin_unlock(&c
->cnt_lock
);
215 if (unlikely(sqnum
>= SQNUM_WARN_WATERMARK
)) {
216 if (sqnum
>= SQNUM_WATERMARK
) {
217 ubifs_err("sequence number overflow %llu, end of life",
219 ubifs_ro_mode(c
, -EINVAL
);
221 ubifs_warn("running out of sequence numbers, end of life soon");
228 * ubifs_prepare_node - prepare node to be written to flash.
229 * @c: UBIFS file-system description object
230 * @node: the node to pad
232 * @pad: if the buffer has to be padded
234 * This function prepares node at @node to be written to the media - it
235 * calculates node CRC, fills the common header, and adds proper padding up to
236 * the next minimum I/O unit if @pad is not zero.
238 void ubifs_prepare_node(struct ubifs_info
*c
, void *node
, int len
, int pad
)
241 struct ubifs_ch
*ch
= node
;
242 unsigned long long sqnum
= next_sqnum(c
);
244 ubifs_assert(len
>= UBIFS_CH_SZ
);
246 ch
->magic
= cpu_to_le32(UBIFS_NODE_MAGIC
);
247 ch
->len
= cpu_to_le32(len
);
248 ch
->group_type
= UBIFS_NO_NODE_GROUP
;
249 ch
->sqnum
= cpu_to_le64(sqnum
);
250 ch
->padding
[0] = ch
->padding
[1] = 0;
251 crc
= crc32(UBIFS_CRC32_INIT
, node
+ 8, len
- 8);
252 ch
->crc
= cpu_to_le32(crc
);
256 pad
= ALIGN(len
, c
->min_io_size
) - len
;
257 ubifs_pad(c
, node
+ len
, pad
);
262 * ubifs_prep_grp_node - prepare node of a group to be written to flash.
263 * @c: UBIFS file-system description object
264 * @node: the node to pad
266 * @last: indicates the last node of the group
268 * This function prepares node at @node to be written to the media - it
269 * calculates node CRC and fills the common header.
271 void ubifs_prep_grp_node(struct ubifs_info
*c
, void *node
, int len
, int last
)
274 struct ubifs_ch
*ch
= node
;
275 unsigned long long sqnum
= next_sqnum(c
);
277 ubifs_assert(len
>= UBIFS_CH_SZ
);
279 ch
->magic
= cpu_to_le32(UBIFS_NODE_MAGIC
);
280 ch
->len
= cpu_to_le32(len
);
282 ch
->group_type
= UBIFS_LAST_OF_NODE_GROUP
;
284 ch
->group_type
= UBIFS_IN_NODE_GROUP
;
285 ch
->sqnum
= cpu_to_le64(sqnum
);
286 ch
->padding
[0] = ch
->padding
[1] = 0;
287 crc
= crc32(UBIFS_CRC32_INIT
, node
+ 8, len
- 8);
288 ch
->crc
= cpu_to_le32(crc
);
292 * wbuf_timer_callback - write-buffer timer callback function.
293 * @data: timer data (write-buffer descriptor)
295 * This function is called when the write-buffer timer expires.
297 static enum hrtimer_restart
wbuf_timer_callback_nolock(struct hrtimer
*timer
)
299 struct ubifs_wbuf
*wbuf
= container_of(timer
, struct ubifs_wbuf
, timer
);
301 dbg_io("jhead %s", dbg_jhead(wbuf
->jhead
));
303 wbuf
->c
->need_wbuf_sync
= 1;
304 ubifs_wake_up_bgt(wbuf
->c
);
305 return HRTIMER_NORESTART
;
309 * new_wbuf_timer - start new write-buffer timer.
310 * @wbuf: write-buffer descriptor
312 static void new_wbuf_timer_nolock(struct ubifs_wbuf
*wbuf
)
314 ubifs_assert(!hrtimer_active(&wbuf
->timer
));
318 dbg_io("set timer for jhead %s, %llu-%llu millisecs",
319 dbg_jhead(wbuf
->jhead
),
320 div_u64(ktime_to_ns(wbuf
->softlimit
), USEC_PER_SEC
),
321 div_u64(ktime_to_ns(wbuf
->softlimit
) + wbuf
->delta
,
323 hrtimer_start_range_ns(&wbuf
->timer
, wbuf
->softlimit
, wbuf
->delta
,
328 * cancel_wbuf_timer - cancel write-buffer timer.
329 * @wbuf: write-buffer descriptor
331 static void cancel_wbuf_timer_nolock(struct ubifs_wbuf
*wbuf
)
336 hrtimer_cancel(&wbuf
->timer
);
340 * ubifs_wbuf_sync_nolock - synchronize write-buffer.
341 * @wbuf: write-buffer to synchronize
343 * This function synchronizes write-buffer @buf and returns zero in case of
344 * success or a negative error code in case of failure.
346 int ubifs_wbuf_sync_nolock(struct ubifs_wbuf
*wbuf
)
348 struct ubifs_info
*c
= wbuf
->c
;
351 cancel_wbuf_timer_nolock(wbuf
);
352 if (!wbuf
->used
|| wbuf
->lnum
== -1)
353 /* Write-buffer is empty or not seeked */
356 dbg_io("LEB %d:%d, %d bytes, jhead %s",
357 wbuf
->lnum
, wbuf
->offs
, wbuf
->used
, dbg_jhead(wbuf
->jhead
));
358 ubifs_assert(!(c
->vfs_sb
->s_flags
& MS_RDONLY
));
359 ubifs_assert(!(wbuf
->avail
& 7));
360 ubifs_assert(wbuf
->offs
+ c
->min_io_size
<= c
->leb_size
);
365 ubifs_pad(c
, wbuf
->buf
+ wbuf
->used
, wbuf
->avail
);
366 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
, wbuf
->offs
,
367 c
->min_io_size
, wbuf
->dtype
);
369 ubifs_err("cannot write %d bytes to LEB %d:%d",
370 c
->min_io_size
, wbuf
->lnum
, wbuf
->offs
);
377 spin_lock(&wbuf
->lock
);
378 wbuf
->offs
+= c
->min_io_size
;
379 wbuf
->avail
= c
->min_io_size
;
382 spin_unlock(&wbuf
->lock
);
384 if (wbuf
->sync_callback
)
385 err
= wbuf
->sync_callback(c
, wbuf
->lnum
,
386 c
->leb_size
- wbuf
->offs
, dirt
);
391 * ubifs_wbuf_seek_nolock - seek write-buffer.
392 * @wbuf: write-buffer
393 * @lnum: logical eraseblock number to seek to
394 * @offs: logical eraseblock offset to seek to
397 * This function targets the write-buffer to logical eraseblock @lnum:@offs.
398 * The write-buffer is synchronized if it is not empty. Returns zero in case of
399 * success and a negative error code in case of failure.
401 int ubifs_wbuf_seek_nolock(struct ubifs_wbuf
*wbuf
, int lnum
, int offs
,
404 const struct ubifs_info
*c
= wbuf
->c
;
406 dbg_io("LEB %d:%d, jhead %s", lnum
, offs
, dbg_jhead(wbuf
->jhead
));
407 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
);
408 ubifs_assert(offs
>= 0 && offs
<= c
->leb_size
);
409 ubifs_assert(offs
% c
->min_io_size
== 0 && !(offs
& 7));
410 ubifs_assert(lnum
!= wbuf
->lnum
);
412 if (wbuf
->used
> 0) {
413 int err
= ubifs_wbuf_sync_nolock(wbuf
);
419 spin_lock(&wbuf
->lock
);
422 wbuf
->avail
= c
->min_io_size
;
424 spin_unlock(&wbuf
->lock
);
431 * ubifs_bg_wbufs_sync - synchronize write-buffers.
432 * @c: UBIFS file-system description object
434 * This function is called by background thread to synchronize write-buffers.
435 * Returns zero in case of success and a negative error code in case of
438 int ubifs_bg_wbufs_sync(struct ubifs_info
*c
)
442 if (!c
->need_wbuf_sync
)
444 c
->need_wbuf_sync
= 0;
451 dbg_io("synchronize");
452 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
453 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
458 * If the mutex is locked then wbuf is being changed, so
459 * synchronization is not necessary.
461 if (mutex_is_locked(&wbuf
->io_mutex
))
464 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
465 if (!wbuf
->need_sync
) {
466 mutex_unlock(&wbuf
->io_mutex
);
470 err
= ubifs_wbuf_sync_nolock(wbuf
);
471 mutex_unlock(&wbuf
->io_mutex
);
473 ubifs_err("cannot sync write-buffer, error %d", err
);
474 ubifs_ro_mode(c
, err
);
482 /* Cancel all timers to prevent repeated errors */
483 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
484 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
486 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
487 cancel_wbuf_timer_nolock(wbuf
);
488 mutex_unlock(&wbuf
->io_mutex
);
494 * ubifs_wbuf_write_nolock - write data to flash via write-buffer.
495 * @wbuf: write-buffer
496 * @buf: node to write
499 * This function writes data to flash via write-buffer @wbuf. This means that
500 * the last piece of the node won't reach the flash media immediately if it
501 * does not take whole minimal I/O unit. Instead, the node will sit in RAM
502 * until the write-buffer is synchronized (e.g., by timer).
504 * This function returns zero in case of success and a negative error code in
505 * case of failure. If the node cannot be written because there is no more
506 * space in this logical eraseblock, %-ENOSPC is returned.
508 int ubifs_wbuf_write_nolock(struct ubifs_wbuf
*wbuf
, void *buf
, int len
)
510 struct ubifs_info
*c
= wbuf
->c
;
511 int err
, written
, n
, aligned_len
= ALIGN(len
, 8), offs
;
513 dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len
,
514 dbg_ntype(((struct ubifs_ch
*)buf
)->node_type
),
515 dbg_jhead(wbuf
->jhead
), wbuf
->lnum
, wbuf
->offs
+ wbuf
->used
);
516 ubifs_assert(len
> 0 && wbuf
->lnum
>= 0 && wbuf
->lnum
< c
->leb_cnt
);
517 ubifs_assert(wbuf
->offs
>= 0 && wbuf
->offs
% c
->min_io_size
== 0);
518 ubifs_assert(!(wbuf
->offs
& 7) && wbuf
->offs
<= c
->leb_size
);
519 ubifs_assert(wbuf
->avail
> 0 && wbuf
->avail
<= c
->min_io_size
);
520 ubifs_assert(mutex_is_locked(&wbuf
->io_mutex
));
522 if (c
->leb_size
- wbuf
->offs
- wbuf
->used
< aligned_len
) {
527 cancel_wbuf_timer_nolock(wbuf
);
532 if (aligned_len
<= wbuf
->avail
) {
534 * The node is not very large and fits entirely within
537 memcpy(wbuf
->buf
+ wbuf
->used
, buf
, len
);
539 if (aligned_len
== wbuf
->avail
) {
540 dbg_io("flush jhead %s wbuf to LEB %d:%d",
541 dbg_jhead(wbuf
->jhead
), wbuf
->lnum
, wbuf
->offs
);
542 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
,
543 wbuf
->offs
, c
->min_io_size
,
548 spin_lock(&wbuf
->lock
);
549 wbuf
->offs
+= c
->min_io_size
;
550 wbuf
->avail
= c
->min_io_size
;
553 spin_unlock(&wbuf
->lock
);
555 spin_lock(&wbuf
->lock
);
556 wbuf
->avail
-= aligned_len
;
557 wbuf
->used
+= aligned_len
;
558 spin_unlock(&wbuf
->lock
);
565 * The node is large enough and does not fit entirely within current
566 * minimal I/O unit. We have to fill and flush write-buffer and switch
567 * to the next min. I/O unit.
569 dbg_io("flush jhead %s wbuf to LEB %d:%d",
570 dbg_jhead(wbuf
->jhead
), wbuf
->lnum
, wbuf
->offs
);
571 memcpy(wbuf
->buf
+ wbuf
->used
, buf
, wbuf
->avail
);
572 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
, wbuf
->offs
,
573 c
->min_io_size
, wbuf
->dtype
);
577 offs
= wbuf
->offs
+ c
->min_io_size
;
579 aligned_len
-= wbuf
->avail
;
580 written
= wbuf
->avail
;
583 * The remaining data may take more whole min. I/O units, so write the
584 * remains multiple to min. I/O unit size directly to the flash media.
585 * We align node length to 8-byte boundary because we anyway flash wbuf
586 * if the remaining space is less than 8 bytes.
588 n
= aligned_len
>> c
->min_io_shift
;
590 n
<<= c
->min_io_shift
;
591 dbg_io("write %d bytes to LEB %d:%d", n
, wbuf
->lnum
, offs
);
592 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, buf
+ written
, offs
, n
,
602 spin_lock(&wbuf
->lock
);
605 * And now we have what's left and what does not take whole
606 * min. I/O unit, so write it to the write-buffer and we are
609 memcpy(wbuf
->buf
, buf
+ written
, len
);
612 wbuf
->used
= aligned_len
;
613 wbuf
->avail
= c
->min_io_size
- aligned_len
;
615 spin_unlock(&wbuf
->lock
);
618 if (wbuf
->sync_callback
) {
619 int free
= c
->leb_size
- wbuf
->offs
- wbuf
->used
;
621 err
= wbuf
->sync_callback(c
, wbuf
->lnum
, free
, 0);
627 new_wbuf_timer_nolock(wbuf
);
632 ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
633 len
, wbuf
->lnum
, wbuf
->offs
, err
);
634 dbg_dump_node(c
, buf
);
636 dbg_dump_leb(c
, wbuf
->lnum
);
641 * ubifs_write_node - write node to the media.
642 * @c: UBIFS file-system description object
643 * @buf: the node to write
645 * @lnum: logical eraseblock number
646 * @offs: offset within the logical eraseblock
647 * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
649 * This function automatically fills node magic number, assigns sequence
650 * number, and calculates node CRC checksum. The length of the @buf buffer has
651 * to be aligned to the minimal I/O unit size. This function automatically
652 * appends padding node and padding bytes if needed. Returns zero in case of
653 * success and a negative error code in case of failure.
655 int ubifs_write_node(struct ubifs_info
*c
, void *buf
, int len
, int lnum
,
658 int err
, buf_len
= ALIGN(len
, c
->min_io_size
);
660 dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
661 lnum
, offs
, dbg_ntype(((struct ubifs_ch
*)buf
)->node_type
), len
,
663 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
664 ubifs_assert(offs
% c
->min_io_size
== 0 && offs
< c
->leb_size
);
669 ubifs_prepare_node(c
, buf
, len
, 1);
670 err
= ubi_leb_write(c
->ubi
, lnum
, buf
, offs
, buf_len
, dtype
);
672 ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
673 buf_len
, lnum
, offs
, err
);
674 dbg_dump_node(c
, buf
);
682 * ubifs_read_node_wbuf - read node from the media or write-buffer.
683 * @wbuf: wbuf to check for un-written data
684 * @buf: buffer to read to
687 * @lnum: logical eraseblock number
688 * @offs: offset within the logical eraseblock
690 * This function reads a node of known type and length, checks it and stores
691 * in @buf. If the node partially or fully sits in the write-buffer, this
692 * function takes data from the buffer, otherwise it reads the flash media.
693 * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
694 * error code in case of failure.
696 int ubifs_read_node_wbuf(struct ubifs_wbuf
*wbuf
, void *buf
, int type
, int len
,
699 const struct ubifs_info
*c
= wbuf
->c
;
700 int err
, rlen
, overlap
;
701 struct ubifs_ch
*ch
= buf
;
703 dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum
, offs
,
704 dbg_ntype(type
), len
, dbg_jhead(wbuf
->jhead
));
705 ubifs_assert(wbuf
&& lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
706 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
707 ubifs_assert(type
>= 0 && type
< UBIFS_NODE_TYPES_CNT
);
709 spin_lock(&wbuf
->lock
);
710 overlap
= (lnum
== wbuf
->lnum
&& offs
+ len
> wbuf
->offs
);
712 /* We may safely unlock the write-buffer and read the data */
713 spin_unlock(&wbuf
->lock
);
714 return ubifs_read_node(c
, buf
, type
, len
, lnum
, offs
);
717 /* Don't read under wbuf */
718 rlen
= wbuf
->offs
- offs
;
722 /* Copy the rest from the write-buffer */
723 memcpy(buf
+ rlen
, wbuf
->buf
+ offs
+ rlen
- wbuf
->offs
, len
- rlen
);
724 spin_unlock(&wbuf
->lock
);
727 /* Read everything that goes before write-buffer */
728 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, rlen
);
729 if (err
&& err
!= -EBADMSG
) {
730 ubifs_err("failed to read node %d from LEB %d:%d, "
731 "error %d", type
, lnum
, offs
, err
);
737 if (type
!= ch
->node_type
) {
738 ubifs_err("bad node type (%d but expected %d)",
739 ch
->node_type
, type
);
743 err
= ubifs_check_node(c
, buf
, lnum
, offs
, 0, 0);
745 ubifs_err("expected node type %d", type
);
749 rlen
= le32_to_cpu(ch
->len
);
751 ubifs_err("bad node length %d, expected %d", rlen
, len
);
758 ubifs_err("bad node at LEB %d:%d", lnum
, offs
);
759 dbg_dump_node(c
, buf
);
765 * ubifs_read_node - read node.
766 * @c: UBIFS file-system description object
767 * @buf: buffer to read to
769 * @len: node length (not aligned)
770 * @lnum: logical eraseblock number
771 * @offs: offset within the logical eraseblock
773 * This function reads a node of known type and and length, checks it and
774 * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
775 * and a negative error code in case of failure.
777 int ubifs_read_node(const struct ubifs_info
*c
, void *buf
, int type
, int len
,
781 struct ubifs_ch
*ch
= buf
;
783 dbg_io("LEB %d:%d, %s, length %d", lnum
, offs
, dbg_ntype(type
), len
);
784 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
785 ubifs_assert(len
>= UBIFS_CH_SZ
&& offs
+ len
<= c
->leb_size
);
786 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
787 ubifs_assert(type
>= 0 && type
< UBIFS_NODE_TYPES_CNT
);
789 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, len
);
790 if (err
&& err
!= -EBADMSG
) {
791 ubifs_err("cannot read node %d from LEB %d:%d, error %d",
792 type
, lnum
, offs
, err
);
796 if (type
!= ch
->node_type
) {
797 ubifs_err("bad node type (%d but expected %d)",
798 ch
->node_type
, type
);
802 err
= ubifs_check_node(c
, buf
, lnum
, offs
, 0, 0);
804 ubifs_err("expected node type %d", type
);
808 l
= le32_to_cpu(ch
->len
);
810 ubifs_err("bad node length %d, expected %d", l
, len
);
817 ubifs_err("bad node at LEB %d:%d", lnum
, offs
);
818 dbg_dump_node(c
, buf
);
824 * ubifs_wbuf_init - initialize write-buffer.
825 * @c: UBIFS file-system description object
826 * @wbuf: write-buffer to initialize
828 * This function initializes write-buffer. Returns zero in case of success
829 * %-ENOMEM in case of failure.
831 int ubifs_wbuf_init(struct ubifs_info
*c
, struct ubifs_wbuf
*wbuf
)
835 wbuf
->buf
= kmalloc(c
->min_io_size
, GFP_KERNEL
);
839 size
= (c
->min_io_size
/ UBIFS_CH_SZ
+ 1) * sizeof(ino_t
);
840 wbuf
->inodes
= kmalloc(size
, GFP_KERNEL
);
848 wbuf
->lnum
= wbuf
->offs
= -1;
849 wbuf
->avail
= c
->min_io_size
;
850 wbuf
->dtype
= UBI_UNKNOWN
;
851 wbuf
->sync_callback
= NULL
;
852 mutex_init(&wbuf
->io_mutex
);
853 spin_lock_init(&wbuf
->lock
);
857 hrtimer_init(&wbuf
->timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
858 wbuf
->timer
.function
= wbuf_timer_callback_nolock
;
859 wbuf
->softlimit
= ktime_set(WBUF_TIMEOUT_SOFTLIMIT
, 0);
860 wbuf
->delta
= WBUF_TIMEOUT_HARDLIMIT
- WBUF_TIMEOUT_SOFTLIMIT
;
861 wbuf
->delta
*= 1000000000ULL;
862 ubifs_assert(wbuf
->delta
<= ULONG_MAX
);
867 * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
868 * @wbuf: the write-buffer where to add
869 * @inum: the inode number
871 * This function adds an inode number to the inode array of the write-buffer.
873 void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf
*wbuf
, ino_t inum
)
876 /* NOR flash or something similar */
879 spin_lock(&wbuf
->lock
);
881 wbuf
->inodes
[wbuf
->next_ino
++] = inum
;
882 spin_unlock(&wbuf
->lock
);
886 * wbuf_has_ino - returns if the wbuf contains data from the inode.
887 * @wbuf: the write-buffer
888 * @inum: the inode number
890 * This function returns with %1 if the write-buffer contains some data from the
891 * given inode otherwise it returns with %0.
893 static int wbuf_has_ino(struct ubifs_wbuf
*wbuf
, ino_t inum
)
897 spin_lock(&wbuf
->lock
);
898 for (i
= 0; i
< wbuf
->next_ino
; i
++)
899 if (inum
== wbuf
->inodes
[i
]) {
903 spin_unlock(&wbuf
->lock
);
909 * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
910 * @c: UBIFS file-system description object
911 * @inode: inode to synchronize
913 * This function synchronizes write-buffers which contain nodes belonging to
914 * @inode. Returns zero in case of success and a negative error code in case of
917 int ubifs_sync_wbufs_by_inode(struct ubifs_info
*c
, struct inode
*inode
)
921 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
922 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
926 * GC head is special, do not look at it. Even if the
927 * head contains something related to this inode, it is
928 * a _copy_ of corresponding on-flash node which sits
933 if (!wbuf_has_ino(wbuf
, inode
->i_ino
))
936 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
937 if (wbuf_has_ino(wbuf
, inode
->i_ino
))
938 err
= ubifs_wbuf_sync_nolock(wbuf
);
939 mutex_unlock(&wbuf
->io_mutex
);
942 ubifs_ro_mode(c
, err
);