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 * UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum
35 * write size (@c->max_write_size). The latter is the maximum amount of bytes
36 * the underlying flash is able to program at a time, and writing in
37 * @c->max_write_size units should presumably be faster. Obviously,
38 * @c->min_io_size <= @c->max_write_size. Write-buffers are of
39 * @c->max_write_size bytes in size for maximum performance. However, when a
40 * write-buffer is flushed, only the portion of it (aligned to @c->min_io_size
41 * boundary) which contains data is written, not the whole write-buffer,
42 * because this is more space-efficient.
44 * This optimization adds few complications to the code. Indeed, on the one
45 * hand, we want to write in optimal @c->max_write_size bytes chunks, which
46 * also means aligning writes at the @c->max_write_size bytes offsets. On the
47 * other hand, we do not want to waste space when synchronizing the write
48 * buffer, so during synchronization we writes in smaller chunks. And this makes
49 * the next write offset to be not aligned to @c->max_write_size bytes. So the
50 * have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned
51 * to @c->max_write_size bytes again. We do this by temporarily shrinking
52 * write-buffer size (@wbuf->size).
54 * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by
55 * mutexes defined inside these objects. Since sometimes upper-level code
56 * has to lock the write-buffer (e.g. journal space reservation code), many
57 * functions related to write-buffers have "nolock" suffix which means that the
58 * caller has to lock the write-buffer before calling this function.
60 * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not
61 * aligned, UBIFS starts the next node from the aligned address, and the padded
62 * bytes may contain any rubbish. In other words, UBIFS does not put padding
63 * bytes in those small gaps. Common headers of nodes store real node lengths,
64 * not aligned lengths. Indexing nodes also store real lengths in branches.
66 * UBIFS uses padding when it pads to the next min. I/O unit. In this case it
67 * uses padding nodes or padding bytes, if the padding node does not fit.
69 * All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when
70 * they are read from the flash media.
73 #include <linux/crc32.h>
74 #include <linux/slab.h>
78 * ubifs_ro_mode - switch UBIFS to read read-only mode.
79 * @c: UBIFS file-system description object
80 * @err: error code which is the reason of switching to R/O mode
82 void ubifs_ro_mode(struct ubifs_info
*c
, int err
)
86 c
->no_chk_data_crc
= 0;
87 c
->vfs_sb
->s_flags
|= MS_RDONLY
;
88 ubifs_warn("switched to read-only mode, error %d", err
);
94 * Below are simple wrappers over UBI I/O functions which include some
95 * additional checks and UBIFS debugging stuff. See corresponding UBI function
96 * for more information.
99 int ubifs_leb_read(const struct ubifs_info
*c
, int lnum
, void *buf
, int offs
,
100 int len
, int even_ebadmsg
)
104 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, len
);
106 * In case of %-EBADMSG print the error message only if the
107 * @even_ebadmsg is true.
109 if (err
&& (err
!= -EBADMSG
|| even_ebadmsg
)) {
110 ubifs_err("reading %d bytes from LEB %d:%d failed, error %d",
111 len
, lnum
, offs
, err
);
117 int ubifs_leb_write(struct ubifs_info
*c
, int lnum
, const void *buf
, int offs
,
122 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
125 if (!dbg_is_tst_rcvry(c
))
126 err
= ubi_leb_write(c
->ubi
, lnum
, buf
, offs
, len
, dtype
);
128 err
= dbg_leb_write(c
->ubi
, lnum
, buf
, offs
, len
, dtype
);
130 ubifs_err("writing %d bytes to LEB %d:%d failed, error %d",
131 len
, lnum
, offs
, err
);
132 ubifs_ro_mode(c
, err
);
138 int ubifs_leb_change(struct ubifs_info
*c
, int lnum
, const void *buf
, int len
,
143 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
146 if (!dbg_is_tst_rcvry(c
))
147 err
= ubi_leb_change(c
->ubi
, lnum
, buf
, len
, dtype
);
149 err
= dbg_leb_change(c
->ubi
, lnum
, buf
, len
, dtype
);
151 ubifs_err("changing %d bytes in LEB %d failed, error %d",
153 ubifs_ro_mode(c
, err
);
159 int ubifs_leb_unmap(struct ubifs_info
*c
, int lnum
)
163 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
166 if (!dbg_is_tst_rcvry(c
))
167 err
= ubi_leb_unmap(c
->ubi
, lnum
);
169 err
= dbg_leb_unmap(c
->ubi
, lnum
);
171 ubifs_err("unmap LEB %d failed, error %d", lnum
, err
);
172 ubifs_ro_mode(c
, err
);
178 int ubifs_leb_map(struct ubifs_info
*c
, int lnum
, int dtype
)
182 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
185 if (!dbg_is_tst_rcvry(c
))
186 err
= ubi_leb_map(c
->ubi
, lnum
, dtype
);
188 err
= dbg_leb_map(c
->ubi
, lnum
, dtype
);
190 ubifs_err("mapping LEB %d failed, error %d", lnum
, err
);
191 ubifs_ro_mode(c
, err
);
197 int ubifs_is_mapped(const struct ubifs_info
*c
, int lnum
)
201 err
= ubi_is_mapped(c
->ubi
, lnum
);
203 ubifs_err("ubi_is_mapped failed for LEB %d, error %d",
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
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.
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
228 * 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
235 * This function returns zero in case of success and %-EUCLEAN in case of bad
238 int ubifs_check_node(const struct ubifs_info
*c
, const void *buf
, int lnum
,
239 int offs
, int quiet
, int must_chk_crc
)
241 int err
= -EINVAL
, type
, node_len
;
242 uint32_t crc
, node_crc
, magic
;
243 const struct ubifs_ch
*ch
= buf
;
245 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
246 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
248 magic
= le32_to_cpu(ch
->magic
);
249 if (magic
!= UBIFS_NODE_MAGIC
) {
251 ubifs_err("bad magic %#08x, expected %#08x",
252 magic
, UBIFS_NODE_MAGIC
);
257 type
= ch
->node_type
;
258 if (type
< 0 || type
>= UBIFS_NODE_TYPES_CNT
) {
260 ubifs_err("bad node type %d", type
);
264 node_len
= le32_to_cpu(ch
->len
);
265 if (node_len
+ offs
> c
->leb_size
)
268 if (c
->ranges
[type
].max_len
== 0) {
269 if (node_len
!= c
->ranges
[type
].len
)
271 } else if (node_len
< c
->ranges
[type
].min_len
||
272 node_len
> c
->ranges
[type
].max_len
)
275 if (!must_chk_crc
&& type
== UBIFS_DATA_NODE
&& !c
->mounting
&&
276 !c
->remounting_rw
&& c
->no_chk_data_crc
)
279 crc
= crc32(UBIFS_CRC32_INIT
, buf
+ 8, node_len
- 8);
280 node_crc
= le32_to_cpu(ch
->crc
);
281 if (crc
!= node_crc
) {
283 ubifs_err("bad CRC: calculated %#08x, read %#08x",
293 ubifs_err("bad node length %d", node_len
);
296 ubifs_err("bad node at LEB %d:%d", lnum
, offs
);
297 dbg_dump_node(c
, buf
);
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
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).
316 * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
319 void ubifs_pad(const struct ubifs_info
*c
, void *buf
, int pad
)
323 ubifs_assert(pad
>= 0 && !(pad
& 7));
325 if (pad
>= UBIFS_PAD_NODE_SZ
) {
326 struct ubifs_ch
*ch
= buf
;
327 struct ubifs_pad_node
*pad_node
= buf
;
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;
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
);
341 /* Too little space, padding node won't fit */
342 memset(buf
, UBIFS_PADDING_BYTE
, pad
);
346 * next_sqnum - get next sequence number.
347 * @c: UBIFS file-system description object
349 static unsigned long long next_sqnum(struct ubifs_info
*c
)
351 unsigned long long sqnum
;
353 spin_lock(&c
->cnt_lock
);
354 sqnum
= ++c
->max_sqnum
;
355 spin_unlock(&c
->cnt_lock
);
357 if (unlikely(sqnum
>= SQNUM_WARN_WATERMARK
)) {
358 if (sqnum
>= SQNUM_WATERMARK
) {
359 ubifs_err("sequence number overflow %llu, end of life",
361 ubifs_ro_mode(c
, -EINVAL
);
363 ubifs_warn("running out of sequence numbers, end of life soon");
370 * ubifs_prepare_node - prepare node to be written to flash.
371 * @c: UBIFS file-system description object
372 * @node: the node to pad
374 * @pad: if the buffer has to be padded
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.
380 void ubifs_prepare_node(struct ubifs_info
*c
, void *node
, int len
, int pad
)
383 struct ubifs_ch
*ch
= node
;
384 unsigned long long sqnum
= next_sqnum(c
);
386 ubifs_assert(len
>= UBIFS_CH_SZ
);
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
);
398 pad
= ALIGN(len
, c
->min_io_size
) - len
;
399 ubifs_pad(c
, node
+ len
, pad
);
404 * 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
408 * @last: indicates the last node of the group
410 * This function prepares node at @node to be written to the media - it
411 * calculates node CRC and fills the common header.
413 void ubifs_prep_grp_node(struct ubifs_info
*c
, void *node
, int len
, int last
)
416 struct ubifs_ch
*ch
= node
;
417 unsigned long long sqnum
= next_sqnum(c
);
419 ubifs_assert(len
>= UBIFS_CH_SZ
);
421 ch
->magic
= cpu_to_le32(UBIFS_NODE_MAGIC
);
422 ch
->len
= cpu_to_le32(len
);
424 ch
->group_type
= UBIFS_LAST_OF_NODE_GROUP
;
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
);
434 * wbuf_timer_callback - write-buffer timer callback function.
435 * @data: timer data (write-buffer descriptor)
437 * This function is called when the write-buffer timer expires.
439 static enum hrtimer_restart
wbuf_timer_callback_nolock(struct hrtimer
*timer
)
441 struct ubifs_wbuf
*wbuf
= container_of(timer
, struct ubifs_wbuf
, timer
);
443 dbg_io("jhead %s", dbg_jhead(wbuf
->jhead
));
445 wbuf
->c
->need_wbuf_sync
= 1;
446 ubifs_wake_up_bgt(wbuf
->c
);
447 return HRTIMER_NORESTART
;
451 * new_wbuf_timer - start new write-buffer timer.
452 * @wbuf: write-buffer descriptor
454 static void new_wbuf_timer_nolock(struct ubifs_wbuf
*wbuf
)
456 ubifs_assert(!hrtimer_active(&wbuf
->timer
));
460 dbg_io("set timer for jhead %s, %llu-%llu millisecs",
461 dbg_jhead(wbuf
->jhead
),
462 div_u64(ktime_to_ns(wbuf
->softlimit
), USEC_PER_SEC
),
463 div_u64(ktime_to_ns(wbuf
->softlimit
) + wbuf
->delta
,
465 hrtimer_start_range_ns(&wbuf
->timer
, wbuf
->softlimit
, wbuf
->delta
,
470 * cancel_wbuf_timer - cancel write-buffer timer.
471 * @wbuf: write-buffer descriptor
473 static void cancel_wbuf_timer_nolock(struct ubifs_wbuf
*wbuf
)
478 hrtimer_cancel(&wbuf
->timer
);
482 * ubifs_wbuf_sync_nolock - synchronize write-buffer.
483 * @wbuf: write-buffer to synchronize
485 * This function synchronizes write-buffer @buf and returns zero in case of
486 * success or a negative error code in case of failure.
488 * Note, although write-buffers are of @c->max_write_size, this function does
489 * not necessarily writes all @c->max_write_size bytes to the flash. Instead,
490 * if the write-buffer is only partially filled with data, only the used part
491 * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized.
492 * This way we waste less space.
494 int ubifs_wbuf_sync_nolock(struct ubifs_wbuf
*wbuf
)
496 struct ubifs_info
*c
= wbuf
->c
;
497 int err
, dirt
, sync_len
;
499 cancel_wbuf_timer_nolock(wbuf
);
500 if (!wbuf
->used
|| wbuf
->lnum
== -1)
501 /* Write-buffer is empty or not seeked */
504 dbg_io("LEB %d:%d, %d bytes, jhead %s",
505 wbuf
->lnum
, wbuf
->offs
, wbuf
->used
, dbg_jhead(wbuf
->jhead
));
506 ubifs_assert(!(wbuf
->avail
& 7));
507 ubifs_assert(wbuf
->offs
+ wbuf
->size
<= c
->leb_size
);
508 ubifs_assert(wbuf
->size
>= c
->min_io_size
);
509 ubifs_assert(wbuf
->size
<= c
->max_write_size
);
510 ubifs_assert(wbuf
->size
% c
->min_io_size
== 0);
511 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
512 if (c
->leb_size
- wbuf
->offs
>= c
->max_write_size
)
513 ubifs_assert(!((wbuf
->offs
+ wbuf
->size
) % c
->max_write_size
));
519 * Do not write whole write buffer but write only the minimum necessary
520 * amount of min. I/O units.
522 sync_len
= ALIGN(wbuf
->used
, c
->min_io_size
);
523 dirt
= sync_len
- wbuf
->used
;
525 ubifs_pad(c
, wbuf
->buf
+ wbuf
->used
, dirt
);
526 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
, wbuf
->offs
,
527 sync_len
, wbuf
->dtype
);
529 ubifs_err("cannot write %d bytes to LEB %d:%d",
530 sync_len
, wbuf
->lnum
, wbuf
->offs
);
535 spin_lock(&wbuf
->lock
);
536 wbuf
->offs
+= sync_len
;
538 * Now @wbuf->offs is not necessarily aligned to @c->max_write_size.
539 * But our goal is to optimize writes and make sure we write in
540 * @c->max_write_size chunks and to @c->max_write_size-aligned offset.
541 * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make
542 * sure that @wbuf->offs + @wbuf->size is aligned to
543 * @c->max_write_size. This way we make sure that after next
544 * write-buffer flush we are again at the optimal offset (aligned to
545 * @c->max_write_size).
547 if (c
->leb_size
- wbuf
->offs
< c
->max_write_size
)
548 wbuf
->size
= c
->leb_size
- wbuf
->offs
;
549 else if (wbuf
->offs
& (c
->max_write_size
- 1))
550 wbuf
->size
= ALIGN(wbuf
->offs
, c
->max_write_size
) - wbuf
->offs
;
552 wbuf
->size
= c
->max_write_size
;
553 wbuf
->avail
= wbuf
->size
;
556 spin_unlock(&wbuf
->lock
);
558 if (wbuf
->sync_callback
)
559 err
= wbuf
->sync_callback(c
, wbuf
->lnum
,
560 c
->leb_size
- wbuf
->offs
, dirt
);
565 * ubifs_wbuf_seek_nolock - seek write-buffer.
566 * @wbuf: write-buffer
567 * @lnum: logical eraseblock number to seek to
568 * @offs: logical eraseblock offset to seek to
571 * This function targets the write-buffer to logical eraseblock @lnum:@offs.
572 * The write-buffer has to be empty. Returns zero in case of success and a
573 * negative error code in case of failure.
575 int ubifs_wbuf_seek_nolock(struct ubifs_wbuf
*wbuf
, int lnum
, int offs
,
578 const struct ubifs_info
*c
= wbuf
->c
;
580 dbg_io("LEB %d:%d, jhead %s", lnum
, offs
, dbg_jhead(wbuf
->jhead
));
581 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
);
582 ubifs_assert(offs
>= 0 && offs
<= c
->leb_size
);
583 ubifs_assert(offs
% c
->min_io_size
== 0 && !(offs
& 7));
584 ubifs_assert(lnum
!= wbuf
->lnum
);
585 ubifs_assert(wbuf
->used
== 0);
587 spin_lock(&wbuf
->lock
);
590 if (c
->leb_size
- wbuf
->offs
< c
->max_write_size
)
591 wbuf
->size
= c
->leb_size
- wbuf
->offs
;
592 else if (wbuf
->offs
& (c
->max_write_size
- 1))
593 wbuf
->size
= ALIGN(wbuf
->offs
, c
->max_write_size
) - wbuf
->offs
;
595 wbuf
->size
= c
->max_write_size
;
596 wbuf
->avail
= wbuf
->size
;
598 spin_unlock(&wbuf
->lock
);
605 * ubifs_bg_wbufs_sync - synchronize write-buffers.
606 * @c: UBIFS file-system description object
608 * This function is called by background thread to synchronize write-buffers.
609 * Returns zero in case of success and a negative error code in case of
612 int ubifs_bg_wbufs_sync(struct ubifs_info
*c
)
616 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
617 if (!c
->need_wbuf_sync
)
619 c
->need_wbuf_sync
= 0;
626 dbg_io("synchronize");
627 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
628 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
633 * If the mutex is locked then wbuf is being changed, so
634 * synchronization is not necessary.
636 if (mutex_is_locked(&wbuf
->io_mutex
))
639 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
640 if (!wbuf
->need_sync
) {
641 mutex_unlock(&wbuf
->io_mutex
);
645 err
= ubifs_wbuf_sync_nolock(wbuf
);
646 mutex_unlock(&wbuf
->io_mutex
);
648 ubifs_err("cannot sync write-buffer, error %d", err
);
649 ubifs_ro_mode(c
, err
);
657 /* Cancel all timers to prevent repeated errors */
658 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
659 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
661 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
662 cancel_wbuf_timer_nolock(wbuf
);
663 mutex_unlock(&wbuf
->io_mutex
);
669 * ubifs_wbuf_write_nolock - write data to flash via write-buffer.
670 * @wbuf: write-buffer
671 * @buf: node to write
674 * This function writes data to flash via write-buffer @wbuf. This means that
675 * the last piece of the node won't reach the flash media immediately if it
676 * does not take whole max. write unit (@c->max_write_size). Instead, the node
677 * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or
678 * because more data are appended to the write-buffer).
680 * This function returns zero in case of success and a negative error code in
681 * case of failure. If the node cannot be written because there is no more
682 * space in this logical eraseblock, %-ENOSPC is returned.
684 int ubifs_wbuf_write_nolock(struct ubifs_wbuf
*wbuf
, void *buf
, int len
)
686 struct ubifs_info
*c
= wbuf
->c
;
687 int err
, written
, n
, aligned_len
= ALIGN(len
, 8);
689 dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len
,
690 dbg_ntype(((struct ubifs_ch
*)buf
)->node_type
),
691 dbg_jhead(wbuf
->jhead
), wbuf
->lnum
, wbuf
->offs
+ wbuf
->used
);
692 ubifs_assert(len
> 0 && wbuf
->lnum
>= 0 && wbuf
->lnum
< c
->leb_cnt
);
693 ubifs_assert(wbuf
->offs
>= 0 && wbuf
->offs
% c
->min_io_size
== 0);
694 ubifs_assert(!(wbuf
->offs
& 7) && wbuf
->offs
<= c
->leb_size
);
695 ubifs_assert(wbuf
->avail
> 0 && wbuf
->avail
<= wbuf
->size
);
696 ubifs_assert(wbuf
->size
>= c
->min_io_size
);
697 ubifs_assert(wbuf
->size
<= c
->max_write_size
);
698 ubifs_assert(wbuf
->size
% c
->min_io_size
== 0);
699 ubifs_assert(mutex_is_locked(&wbuf
->io_mutex
));
700 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
701 ubifs_assert(!c
->space_fixup
);
702 if (c
->leb_size
- wbuf
->offs
>= c
->max_write_size
)
703 ubifs_assert(!((wbuf
->offs
+ wbuf
->size
) % c
->max_write_size
));
705 if (c
->leb_size
- wbuf
->offs
- wbuf
->used
< aligned_len
) {
710 cancel_wbuf_timer_nolock(wbuf
);
715 if (aligned_len
<= wbuf
->avail
) {
717 * The node is not very large and fits entirely within
720 memcpy(wbuf
->buf
+ wbuf
->used
, buf
, len
);
722 if (aligned_len
== wbuf
->avail
) {
723 dbg_io("flush jhead %s wbuf to LEB %d:%d",
724 dbg_jhead(wbuf
->jhead
), wbuf
->lnum
, wbuf
->offs
);
725 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
,
726 wbuf
->offs
, wbuf
->size
,
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
;
736 wbuf
->size
= c
->leb_size
- wbuf
->offs
;
737 wbuf
->avail
= wbuf
->size
;
740 spin_unlock(&wbuf
->lock
);
742 spin_lock(&wbuf
->lock
);
743 wbuf
->avail
-= aligned_len
;
744 wbuf
->used
+= aligned_len
;
745 spin_unlock(&wbuf
->lock
);
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.
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
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, wbuf
->buf
, wbuf
->offs
,
763 wbuf
->size
, wbuf
->dtype
);
767 wbuf
->offs
+= wbuf
->size
;
769 aligned_len
-= wbuf
->avail
;
770 written
+= wbuf
->avail
;
771 } else if (wbuf
->offs
& (c
->max_write_size
- 1)) {
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
779 dbg_io("write %d bytes to LEB %d:%d",
780 wbuf
->size
, wbuf
->lnum
, wbuf
->offs
);
781 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, buf
, wbuf
->offs
,
782 wbuf
->size
, wbuf
->dtype
);
786 wbuf
->offs
+= wbuf
->size
;
788 aligned_len
-= wbuf
->size
;
789 written
+= wbuf
->size
;
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.
798 n
= aligned_len
>> c
->max_write_shift
;
800 n
<<= c
->max_write_shift
;
801 dbg_io("write %d bytes to LEB %d:%d", n
, wbuf
->lnum
,
803 err
= ubi_leb_write(c
->ubi
, wbuf
->lnum
, buf
+ written
,
804 wbuf
->offs
, n
, wbuf
->dtype
);
813 spin_lock(&wbuf
->lock
);
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
820 memcpy(wbuf
->buf
, buf
+ written
, len
);
822 if (c
->leb_size
- wbuf
->offs
>= c
->max_write_size
)
823 wbuf
->size
= c
->max_write_size
;
825 wbuf
->size
= c
->leb_size
- wbuf
->offs
;
826 wbuf
->avail
= wbuf
->size
- aligned_len
;
827 wbuf
->used
= aligned_len
;
829 spin_unlock(&wbuf
->lock
);
832 if (wbuf
->sync_callback
) {
833 int free
= c
->leb_size
- wbuf
->offs
- wbuf
->used
;
835 err
= wbuf
->sync_callback(c
, wbuf
->lnum
, free
, 0);
841 new_wbuf_timer_nolock(wbuf
);
846 ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
847 len
, wbuf
->lnum
, wbuf
->offs
, err
);
848 dbg_dump_node(c
, buf
);
850 dbg_dump_leb(c
, wbuf
->lnum
);
855 * ubifs_write_node - write node to the media.
856 * @c: UBIFS file-system description object
857 * @buf: the node to write
859 * @lnum: logical eraseblock number
860 * @offs: offset within the logical eraseblock
861 * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
863 * This function automatically fills node magic number, assigns sequence
864 * number, and calculates node CRC checksum. The length of the @buf buffer has
865 * to be aligned to the minimal I/O unit size. This function automatically
866 * appends padding node and padding bytes if needed. Returns zero in case of
867 * success and a negative error code in case of failure.
869 int ubifs_write_node(struct ubifs_info
*c
, void *buf
, int len
, int lnum
,
872 int err
, buf_len
= ALIGN(len
, c
->min_io_size
);
874 dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
875 lnum
, offs
, dbg_ntype(((struct ubifs_ch
*)buf
)->node_type
), len
,
877 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
878 ubifs_assert(offs
% c
->min_io_size
== 0 && offs
< c
->leb_size
);
879 ubifs_assert(!c
->ro_media
&& !c
->ro_mount
);
880 ubifs_assert(!c
->space_fixup
);
885 ubifs_prepare_node(c
, buf
, len
, 1);
886 err
= ubi_leb_write(c
->ubi
, lnum
, buf
, offs
, buf_len
, dtype
);
888 ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
889 buf_len
, lnum
, offs
, err
);
890 dbg_dump_node(c
, buf
);
898 * ubifs_read_node_wbuf - read node from the media or write-buffer.
899 * @wbuf: wbuf to check for un-written data
900 * @buf: buffer to read to
903 * @lnum: logical eraseblock number
904 * @offs: offset within the logical eraseblock
906 * This function reads a node of known type and length, checks it and stores
907 * in @buf. If the node partially or fully sits in the write-buffer, this
908 * function takes data from the buffer, otherwise it reads the flash media.
909 * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
910 * error code in case of failure.
912 int ubifs_read_node_wbuf(struct ubifs_wbuf
*wbuf
, void *buf
, int type
, int len
,
915 const struct ubifs_info
*c
= wbuf
->c
;
916 int err
, rlen
, overlap
;
917 struct ubifs_ch
*ch
= buf
;
919 dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum
, offs
,
920 dbg_ntype(type
), len
, dbg_jhead(wbuf
->jhead
));
921 ubifs_assert(wbuf
&& lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
922 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
923 ubifs_assert(type
>= 0 && type
< UBIFS_NODE_TYPES_CNT
);
925 spin_lock(&wbuf
->lock
);
926 overlap
= (lnum
== wbuf
->lnum
&& offs
+ len
> wbuf
->offs
);
928 /* We may safely unlock the write-buffer and read the data */
929 spin_unlock(&wbuf
->lock
);
930 return ubifs_read_node(c
, buf
, type
, len
, lnum
, offs
);
933 /* Don't read under wbuf */
934 rlen
= wbuf
->offs
- offs
;
938 /* Copy the rest from the write-buffer */
939 memcpy(buf
+ rlen
, wbuf
->buf
+ offs
+ rlen
- wbuf
->offs
, len
- rlen
);
940 spin_unlock(&wbuf
->lock
);
943 /* Read everything that goes before write-buffer */
944 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, rlen
);
945 if (err
&& err
!= -EBADMSG
) {
946 ubifs_err("failed to read node %d from LEB %d:%d, "
947 "error %d", type
, lnum
, offs
, err
);
953 if (type
!= ch
->node_type
) {
954 ubifs_err("bad node type (%d but expected %d)",
955 ch
->node_type
, type
);
959 err
= ubifs_check_node(c
, buf
, lnum
, offs
, 0, 0);
961 ubifs_err("expected node type %d", type
);
965 rlen
= le32_to_cpu(ch
->len
);
967 ubifs_err("bad node length %d, expected %d", rlen
, len
);
974 ubifs_err("bad node at LEB %d:%d", lnum
, offs
);
975 dbg_dump_node(c
, buf
);
981 * ubifs_read_node - read node.
982 * @c: UBIFS file-system description object
983 * @buf: buffer to read to
985 * @len: node length (not aligned)
986 * @lnum: logical eraseblock number
987 * @offs: offset within the logical eraseblock
989 * This function reads a node of known type and and length, checks it and
990 * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
991 * and a negative error code in case of failure.
993 int ubifs_read_node(const struct ubifs_info
*c
, void *buf
, int type
, int len
,
997 struct ubifs_ch
*ch
= buf
;
999 dbg_io("LEB %d:%d, %s, length %d", lnum
, offs
, dbg_ntype(type
), len
);
1000 ubifs_assert(lnum
>= 0 && lnum
< c
->leb_cnt
&& offs
>= 0);
1001 ubifs_assert(len
>= UBIFS_CH_SZ
&& offs
+ len
<= c
->leb_size
);
1002 ubifs_assert(!(offs
& 7) && offs
< c
->leb_size
);
1003 ubifs_assert(type
>= 0 && type
< UBIFS_NODE_TYPES_CNT
);
1005 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, len
);
1006 if (err
&& err
!= -EBADMSG
) {
1007 ubifs_err("cannot read node %d from LEB %d:%d, error %d",
1008 type
, lnum
, offs
, err
);
1012 if (type
!= ch
->node_type
) {
1013 ubifs_err("bad node type (%d but expected %d)",
1014 ch
->node_type
, type
);
1018 err
= ubifs_check_node(c
, buf
, lnum
, offs
, 0, 0);
1020 ubifs_err("expected node type %d", type
);
1024 l
= le32_to_cpu(ch
->len
);
1026 ubifs_err("bad node length %d, expected %d", l
, len
);
1033 ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum
, offs
,
1034 ubi_is_mapped(c
->ubi
, lnum
));
1035 dbg_dump_node(c
, buf
);
1041 * ubifs_wbuf_init - initialize write-buffer.
1042 * @c: UBIFS file-system description object
1043 * @wbuf: write-buffer to initialize
1045 * This function initializes write-buffer. Returns zero in case of success
1046 * %-ENOMEM in case of failure.
1048 int ubifs_wbuf_init(struct ubifs_info
*c
, struct ubifs_wbuf
*wbuf
)
1052 wbuf
->buf
= kmalloc(c
->max_write_size
, GFP_KERNEL
);
1056 size
= (c
->max_write_size
/ UBIFS_CH_SZ
+ 1) * sizeof(ino_t
);
1057 wbuf
->inodes
= kmalloc(size
, GFP_KERNEL
);
1058 if (!wbuf
->inodes
) {
1065 wbuf
->lnum
= wbuf
->offs
= -1;
1067 * If the LEB starts at the max. write size aligned address, then
1068 * write-buffer size has to be set to @c->max_write_size. Otherwise,
1069 * set it to something smaller so that it ends at the closest max.
1070 * write size boundary.
1072 size
= c
->max_write_size
- (c
->leb_start
% c
->max_write_size
);
1073 wbuf
->avail
= wbuf
->size
= size
;
1074 wbuf
->dtype
= UBI_UNKNOWN
;
1075 wbuf
->sync_callback
= NULL
;
1076 mutex_init(&wbuf
->io_mutex
);
1077 spin_lock_init(&wbuf
->lock
);
1081 hrtimer_init(&wbuf
->timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
1082 wbuf
->timer
.function
= wbuf_timer_callback_nolock
;
1083 wbuf
->softlimit
= ktime_set(WBUF_TIMEOUT_SOFTLIMIT
, 0);
1084 wbuf
->delta
= WBUF_TIMEOUT_HARDLIMIT
- WBUF_TIMEOUT_SOFTLIMIT
;
1085 wbuf
->delta
*= 1000000000ULL;
1086 ubifs_assert(wbuf
->delta
<= ULONG_MAX
);
1091 * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
1092 * @wbuf: the write-buffer where to add
1093 * @inum: the inode number
1095 * This function adds an inode number to the inode array of the write-buffer.
1097 void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf
*wbuf
, ino_t inum
)
1100 /* NOR flash or something similar */
1103 spin_lock(&wbuf
->lock
);
1105 wbuf
->inodes
[wbuf
->next_ino
++] = inum
;
1106 spin_unlock(&wbuf
->lock
);
1110 * wbuf_has_ino - returns if the wbuf contains data from the inode.
1111 * @wbuf: the write-buffer
1112 * @inum: the inode number
1114 * This function returns with %1 if the write-buffer contains some data from the
1115 * given inode otherwise it returns with %0.
1117 static int wbuf_has_ino(struct ubifs_wbuf
*wbuf
, ino_t inum
)
1121 spin_lock(&wbuf
->lock
);
1122 for (i
= 0; i
< wbuf
->next_ino
; i
++)
1123 if (inum
== wbuf
->inodes
[i
]) {
1127 spin_unlock(&wbuf
->lock
);
1133 * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
1134 * @c: UBIFS file-system description object
1135 * @inode: inode to synchronize
1137 * This function synchronizes write-buffers which contain nodes belonging to
1138 * @inode. Returns zero in case of success and a negative error code in case of
1141 int ubifs_sync_wbufs_by_inode(struct ubifs_info
*c
, struct inode
*inode
)
1145 for (i
= 0; i
< c
->jhead_cnt
; i
++) {
1146 struct ubifs_wbuf
*wbuf
= &c
->jheads
[i
].wbuf
;
1150 * GC head is special, do not look at it. Even if the
1151 * head contains something related to this inode, it is
1152 * a _copy_ of corresponding on-flash node which sits
1157 if (!wbuf_has_ino(wbuf
, inode
->i_ino
))
1160 mutex_lock_nested(&wbuf
->io_mutex
, wbuf
->jhead
);
1161 if (wbuf_has_ino(wbuf
, inode
->i_ino
))
1162 err
= ubifs_wbuf_sync_nolock(wbuf
);
1163 mutex_unlock(&wbuf
->io_mutex
);
1166 ubifs_ro_mode(c
, err
);