Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of UBIFS. |
| 3 | * |
| 4 | * Copyright (C) 2006-2008 Nokia Corporation. |
| 5 | * Copyright (C) 2006, 2007 University of Szeged, Hungary |
| 6 | * |
| 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. |
| 10 | * |
| 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 |
| 14 | * more details. |
| 15 | * |
| 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 |
| 19 | * |
| 20 | * Authors: Artem Bityutskiy (Битюцкий Артём) |
| 21 | * Adrian Hunter |
| 22 | * Zoltan Sogor |
| 23 | */ |
| 24 | |
| 25 | /* |
| 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 |
Artem Bityutskiy | 6f7ab6d | 2009-01-27 16:12:31 +0200 | [diff] [blame] | 32 | * similar to the mechanism is used by JFFS2. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 33 | * |
| 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. |
| 39 | * |
| 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. |
| 45 | * |
| 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. |
| 48 | * |
| 49 | * All UBIFS nodes are protected by CRC checksums and UBIFS checks all nodes |
| 50 | * every time they are read from the flash media. |
| 51 | */ |
| 52 | |
| 53 | #include <linux/crc32.h> |
| 54 | #include "ubifs.h" |
| 55 | |
| 56 | /** |
Adrian Hunter | ff46d7b | 2008-07-21 15:39:05 +0300 | [diff] [blame] | 57 | * ubifs_ro_mode - switch UBIFS to read read-only mode. |
| 58 | * @c: UBIFS file-system description object |
| 59 | * @err: error code which is the reason of switching to R/O mode |
| 60 | */ |
| 61 | void ubifs_ro_mode(struct ubifs_info *c, int err) |
| 62 | { |
| 63 | if (!c->ro_media) { |
| 64 | c->ro_media = 1; |
Artem Bityutskiy | ccb3eba | 2008-09-08 16:07:01 +0300 | [diff] [blame] | 65 | c->no_chk_data_crc = 0; |
Adrian Hunter | ff46d7b | 2008-07-21 15:39:05 +0300 | [diff] [blame] | 66 | ubifs_warn("switched to read-only mode, error %d", err); |
| 67 | dbg_dump_stack(); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | /** |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 72 | * ubifs_check_node - check node. |
| 73 | * @c: UBIFS file-system description object |
| 74 | * @buf: node to check |
| 75 | * @lnum: logical eraseblock number |
| 76 | * @offs: offset within the logical eraseblock |
| 77 | * @quiet: print no messages |
Artem Bityutskiy | 6f7ab6d | 2009-01-27 16:12:31 +0200 | [diff] [blame] | 78 | * @must_chk_crc: indicates whether to always check the CRC |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 79 | * |
| 80 | * This function checks node magic number and CRC checksum. This function also |
| 81 | * validates node length to prevent UBIFS from becoming crazy when an attacker |
| 82 | * feeds it a file-system image with incorrect nodes. For example, too large |
| 83 | * node length in the common header could cause UBIFS to read memory outside of |
| 84 | * allocated buffer when checking the CRC checksum. |
| 85 | * |
Artem Bityutskiy | 6f7ab6d | 2009-01-27 16:12:31 +0200 | [diff] [blame] | 86 | * This function may skip data nodes CRC checking if @c->no_chk_data_crc is |
| 87 | * true, which is controlled by corresponding UBIFS mount option. However, if |
| 88 | * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is |
| 89 | * checked. Similarly, if @c->always_chk_crc is true, @c->no_chk_data_crc is |
| 90 | * ignored and CRC is checked. |
| 91 | * |
| 92 | * This function returns zero in case of success and %-EUCLEAN in case of bad |
| 93 | * CRC or magic. |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 94 | */ |
| 95 | int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, |
Artem Bityutskiy | 6f7ab6d | 2009-01-27 16:12:31 +0200 | [diff] [blame] | 96 | int offs, int quiet, int must_chk_crc) |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 97 | { |
| 98 | int err = -EINVAL, type, node_len; |
| 99 | uint32_t crc, node_crc, magic; |
| 100 | const struct ubifs_ch *ch = buf; |
| 101 | |
| 102 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
| 103 | ubifs_assert(!(offs & 7) && offs < c->leb_size); |
| 104 | |
| 105 | magic = le32_to_cpu(ch->magic); |
| 106 | if (magic != UBIFS_NODE_MAGIC) { |
| 107 | if (!quiet) |
| 108 | ubifs_err("bad magic %#08x, expected %#08x", |
| 109 | magic, UBIFS_NODE_MAGIC); |
| 110 | err = -EUCLEAN; |
| 111 | goto out; |
| 112 | } |
| 113 | |
| 114 | type = ch->node_type; |
| 115 | if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { |
| 116 | if (!quiet) |
| 117 | ubifs_err("bad node type %d", type); |
| 118 | goto out; |
| 119 | } |
| 120 | |
| 121 | node_len = le32_to_cpu(ch->len); |
| 122 | if (node_len + offs > c->leb_size) |
| 123 | goto out_len; |
| 124 | |
| 125 | if (c->ranges[type].max_len == 0) { |
| 126 | if (node_len != c->ranges[type].len) |
| 127 | goto out_len; |
| 128 | } else if (node_len < c->ranges[type].min_len || |
| 129 | node_len > c->ranges[type].max_len) |
| 130 | goto out_len; |
| 131 | |
Artem Bityutskiy | 6f7ab6d | 2009-01-27 16:12:31 +0200 | [diff] [blame] | 132 | if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->always_chk_crc && |
| 133 | c->no_chk_data_crc) |
| 134 | return 0; |
Adrian Hunter | 2953e73 | 2008-09-04 16:26:00 +0300 | [diff] [blame] | 135 | |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 136 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); |
| 137 | node_crc = le32_to_cpu(ch->crc); |
| 138 | if (crc != node_crc) { |
| 139 | if (!quiet) |
| 140 | ubifs_err("bad CRC: calculated %#08x, read %#08x", |
| 141 | crc, node_crc); |
| 142 | err = -EUCLEAN; |
| 143 | goto out; |
| 144 | } |
| 145 | |
| 146 | return 0; |
| 147 | |
| 148 | out_len: |
| 149 | if (!quiet) |
| 150 | ubifs_err("bad node length %d", node_len); |
| 151 | out: |
| 152 | if (!quiet) { |
| 153 | ubifs_err("bad node at LEB %d:%d", lnum, offs); |
| 154 | dbg_dump_node(c, buf); |
| 155 | dbg_dump_stack(); |
| 156 | } |
| 157 | return err; |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * ubifs_pad - pad flash space. |
| 162 | * @c: UBIFS file-system description object |
| 163 | * @buf: buffer to put padding to |
| 164 | * @pad: how many bytes to pad |
| 165 | * |
| 166 | * The flash media obliges us to write only in chunks of %c->min_io_size and |
| 167 | * when we have to write less data we add padding node to the write-buffer and |
| 168 | * pad it to the next minimal I/O unit's boundary. Padding nodes help when the |
| 169 | * media is being scanned. If the amount of wasted space is not enough to fit a |
| 170 | * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes |
| 171 | * pattern (%UBIFS_PADDING_BYTE). |
| 172 | * |
| 173 | * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is |
| 174 | * used. |
| 175 | */ |
| 176 | void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) |
| 177 | { |
| 178 | uint32_t crc; |
| 179 | |
| 180 | ubifs_assert(pad >= 0 && !(pad & 7)); |
| 181 | |
| 182 | if (pad >= UBIFS_PAD_NODE_SZ) { |
| 183 | struct ubifs_ch *ch = buf; |
| 184 | struct ubifs_pad_node *pad_node = buf; |
| 185 | |
| 186 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
| 187 | ch->node_type = UBIFS_PAD_NODE; |
| 188 | ch->group_type = UBIFS_NO_NODE_GROUP; |
| 189 | ch->padding[0] = ch->padding[1] = 0; |
| 190 | ch->sqnum = 0; |
| 191 | ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); |
| 192 | pad -= UBIFS_PAD_NODE_SZ; |
| 193 | pad_node->pad_len = cpu_to_le32(pad); |
| 194 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); |
| 195 | ch->crc = cpu_to_le32(crc); |
| 196 | memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); |
| 197 | } else if (pad > 0) |
| 198 | /* Too little space, padding node won't fit */ |
| 199 | memset(buf, UBIFS_PADDING_BYTE, pad); |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * next_sqnum - get next sequence number. |
| 204 | * @c: UBIFS file-system description object |
| 205 | */ |
| 206 | static unsigned long long next_sqnum(struct ubifs_info *c) |
| 207 | { |
| 208 | unsigned long long sqnum; |
| 209 | |
| 210 | spin_lock(&c->cnt_lock); |
| 211 | sqnum = ++c->max_sqnum; |
| 212 | spin_unlock(&c->cnt_lock); |
| 213 | |
| 214 | if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { |
| 215 | if (sqnum >= SQNUM_WATERMARK) { |
| 216 | ubifs_err("sequence number overflow %llu, end of life", |
| 217 | sqnum); |
| 218 | ubifs_ro_mode(c, -EINVAL); |
| 219 | } |
| 220 | ubifs_warn("running out of sequence numbers, end of life soon"); |
| 221 | } |
| 222 | |
| 223 | return sqnum; |
| 224 | } |
| 225 | |
| 226 | /** |
| 227 | * ubifs_prepare_node - prepare node to be written to flash. |
| 228 | * @c: UBIFS file-system description object |
| 229 | * @node: the node to pad |
| 230 | * @len: node length |
| 231 | * @pad: if the buffer has to be padded |
| 232 | * |
| 233 | * This function prepares node at @node to be written to the media - it |
| 234 | * calculates node CRC, fills the common header, and adds proper padding up to |
| 235 | * the next minimum I/O unit if @pad is not zero. |
| 236 | */ |
| 237 | void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) |
| 238 | { |
| 239 | uint32_t crc; |
| 240 | struct ubifs_ch *ch = node; |
| 241 | unsigned long long sqnum = next_sqnum(c); |
| 242 | |
| 243 | ubifs_assert(len >= UBIFS_CH_SZ); |
| 244 | |
| 245 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
| 246 | ch->len = cpu_to_le32(len); |
| 247 | ch->group_type = UBIFS_NO_NODE_GROUP; |
| 248 | ch->sqnum = cpu_to_le64(sqnum); |
| 249 | ch->padding[0] = ch->padding[1] = 0; |
| 250 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); |
| 251 | ch->crc = cpu_to_le32(crc); |
| 252 | |
| 253 | if (pad) { |
| 254 | len = ALIGN(len, 8); |
| 255 | pad = ALIGN(len, c->min_io_size) - len; |
| 256 | ubifs_pad(c, node + len, pad); |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * ubifs_prep_grp_node - prepare node of a group to be written to flash. |
| 262 | * @c: UBIFS file-system description object |
| 263 | * @node: the node to pad |
| 264 | * @len: node length |
| 265 | * @last: indicates the last node of the group |
| 266 | * |
| 267 | * This function prepares node at @node to be written to the media - it |
| 268 | * calculates node CRC and fills the common header. |
| 269 | */ |
| 270 | void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) |
| 271 | { |
| 272 | uint32_t crc; |
| 273 | struct ubifs_ch *ch = node; |
| 274 | unsigned long long sqnum = next_sqnum(c); |
| 275 | |
| 276 | ubifs_assert(len >= UBIFS_CH_SZ); |
| 277 | |
| 278 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
| 279 | ch->len = cpu_to_le32(len); |
| 280 | if (last) |
| 281 | ch->group_type = UBIFS_LAST_OF_NODE_GROUP; |
| 282 | else |
| 283 | ch->group_type = UBIFS_IN_NODE_GROUP; |
| 284 | ch->sqnum = cpu_to_le64(sqnum); |
| 285 | ch->padding[0] = ch->padding[1] = 0; |
| 286 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); |
| 287 | ch->crc = cpu_to_le32(crc); |
| 288 | } |
| 289 | |
| 290 | /** |
| 291 | * wbuf_timer_callback - write-buffer timer callback function. |
| 292 | * @data: timer data (write-buffer descriptor) |
| 293 | * |
| 294 | * This function is called when the write-buffer timer expires. |
| 295 | */ |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 296 | static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 297 | { |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 298 | struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 299 | |
| 300 | wbuf->need_sync = 1; |
| 301 | wbuf->c->need_wbuf_sync = 1; |
| 302 | ubifs_wake_up_bgt(wbuf->c); |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 303 | return HRTIMER_NORESTART; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 304 | } |
| 305 | |
| 306 | /** |
| 307 | * new_wbuf_timer - start new write-buffer timer. |
| 308 | * @wbuf: write-buffer descriptor |
| 309 | */ |
| 310 | static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) |
| 311 | { |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 312 | ubifs_assert(!hrtimer_active(&wbuf->timer)); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 313 | |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 314 | if (!ktime_to_ns(wbuf->softlimit)) |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 315 | return; |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 316 | hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, |
| 317 | HRTIMER_MODE_REL); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 318 | } |
| 319 | |
| 320 | /** |
| 321 | * cancel_wbuf_timer - cancel write-buffer timer. |
| 322 | * @wbuf: write-buffer descriptor |
| 323 | */ |
| 324 | static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) |
| 325 | { |
| 326 | /* |
| 327 | * If the syncer is waiting for the lock (from the background thread's |
| 328 | * context) and another task is changing write-buffer then the syncing |
| 329 | * should be canceled. |
| 330 | */ |
| 331 | wbuf->need_sync = 0; |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 332 | hrtimer_cancel(&wbuf->timer); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 333 | } |
| 334 | |
| 335 | /** |
| 336 | * ubifs_wbuf_sync_nolock - synchronize write-buffer. |
| 337 | * @wbuf: write-buffer to synchronize |
| 338 | * |
| 339 | * This function synchronizes write-buffer @buf and returns zero in case of |
| 340 | * success or a negative error code in case of failure. |
| 341 | */ |
| 342 | int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) |
| 343 | { |
| 344 | struct ubifs_info *c = wbuf->c; |
| 345 | int err, dirt; |
| 346 | |
| 347 | cancel_wbuf_timer_nolock(wbuf); |
| 348 | if (!wbuf->used || wbuf->lnum == -1) |
| 349 | /* Write-buffer is empty or not seeked */ |
| 350 | return 0; |
| 351 | |
| 352 | dbg_io("LEB %d:%d, %d bytes", |
| 353 | wbuf->lnum, wbuf->offs, wbuf->used); |
| 354 | ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY)); |
| 355 | ubifs_assert(!(wbuf->avail & 7)); |
| 356 | ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size); |
| 357 | |
| 358 | if (c->ro_media) |
| 359 | return -EROFS; |
| 360 | |
| 361 | ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail); |
| 362 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, |
| 363 | c->min_io_size, wbuf->dtype); |
| 364 | if (err) { |
| 365 | ubifs_err("cannot write %d bytes to LEB %d:%d", |
| 366 | c->min_io_size, wbuf->lnum, wbuf->offs); |
| 367 | dbg_dump_stack(); |
| 368 | return err; |
| 369 | } |
| 370 | |
| 371 | dirt = wbuf->avail; |
| 372 | |
| 373 | spin_lock(&wbuf->lock); |
| 374 | wbuf->offs += c->min_io_size; |
| 375 | wbuf->avail = c->min_io_size; |
| 376 | wbuf->used = 0; |
| 377 | wbuf->next_ino = 0; |
| 378 | spin_unlock(&wbuf->lock); |
| 379 | |
| 380 | if (wbuf->sync_callback) |
| 381 | err = wbuf->sync_callback(c, wbuf->lnum, |
| 382 | c->leb_size - wbuf->offs, dirt); |
| 383 | return err; |
| 384 | } |
| 385 | |
| 386 | /** |
| 387 | * ubifs_wbuf_seek_nolock - seek write-buffer. |
| 388 | * @wbuf: write-buffer |
| 389 | * @lnum: logical eraseblock number to seek to |
| 390 | * @offs: logical eraseblock offset to seek to |
| 391 | * @dtype: data type |
| 392 | * |
| 393 | * This function targets the write buffer to logical eraseblock @lnum:@offs. |
| 394 | * The write-buffer is synchronized if it is not empty. Returns zero in case of |
| 395 | * success and a negative error code in case of failure. |
| 396 | */ |
| 397 | int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs, |
| 398 | int dtype) |
| 399 | { |
| 400 | const struct ubifs_info *c = wbuf->c; |
| 401 | |
| 402 | dbg_io("LEB %d:%d", lnum, offs); |
| 403 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt); |
| 404 | ubifs_assert(offs >= 0 && offs <= c->leb_size); |
| 405 | ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7)); |
| 406 | ubifs_assert(lnum != wbuf->lnum); |
| 407 | |
| 408 | if (wbuf->used > 0) { |
| 409 | int err = ubifs_wbuf_sync_nolock(wbuf); |
| 410 | |
| 411 | if (err) |
| 412 | return err; |
| 413 | } |
| 414 | |
| 415 | spin_lock(&wbuf->lock); |
| 416 | wbuf->lnum = lnum; |
| 417 | wbuf->offs = offs; |
| 418 | wbuf->avail = c->min_io_size; |
| 419 | wbuf->used = 0; |
| 420 | spin_unlock(&wbuf->lock); |
| 421 | wbuf->dtype = dtype; |
| 422 | |
| 423 | return 0; |
| 424 | } |
| 425 | |
| 426 | /** |
| 427 | * ubifs_bg_wbufs_sync - synchronize write-buffers. |
| 428 | * @c: UBIFS file-system description object |
| 429 | * |
| 430 | * This function is called by background thread to synchronize write-buffers. |
| 431 | * Returns zero in case of success and a negative error code in case of |
| 432 | * failure. |
| 433 | */ |
| 434 | int ubifs_bg_wbufs_sync(struct ubifs_info *c) |
| 435 | { |
| 436 | int err, i; |
| 437 | |
| 438 | if (!c->need_wbuf_sync) |
| 439 | return 0; |
| 440 | c->need_wbuf_sync = 0; |
| 441 | |
| 442 | if (c->ro_media) { |
| 443 | err = -EROFS; |
| 444 | goto out_timers; |
| 445 | } |
| 446 | |
| 447 | dbg_io("synchronize"); |
| 448 | for (i = 0; i < c->jhead_cnt; i++) { |
| 449 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
| 450 | |
| 451 | cond_resched(); |
| 452 | |
| 453 | /* |
| 454 | * If the mutex is locked then wbuf is being changed, so |
| 455 | * synchronization is not necessary. |
| 456 | */ |
| 457 | if (mutex_is_locked(&wbuf->io_mutex)) |
| 458 | continue; |
| 459 | |
| 460 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
| 461 | if (!wbuf->need_sync) { |
| 462 | mutex_unlock(&wbuf->io_mutex); |
| 463 | continue; |
| 464 | } |
| 465 | |
| 466 | err = ubifs_wbuf_sync_nolock(wbuf); |
| 467 | mutex_unlock(&wbuf->io_mutex); |
| 468 | if (err) { |
| 469 | ubifs_err("cannot sync write-buffer, error %d", err); |
| 470 | ubifs_ro_mode(c, err); |
| 471 | goto out_timers; |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | return 0; |
| 476 | |
| 477 | out_timers: |
| 478 | /* Cancel all timers to prevent repeated errors */ |
| 479 | for (i = 0; i < c->jhead_cnt; i++) { |
| 480 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
| 481 | |
| 482 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
| 483 | cancel_wbuf_timer_nolock(wbuf); |
| 484 | mutex_unlock(&wbuf->io_mutex); |
| 485 | } |
| 486 | return err; |
| 487 | } |
| 488 | |
| 489 | /** |
| 490 | * ubifs_wbuf_write_nolock - write data to flash via write-buffer. |
| 491 | * @wbuf: write-buffer |
| 492 | * @buf: node to write |
| 493 | * @len: node length |
| 494 | * |
| 495 | * This function writes data to flash via write-buffer @wbuf. This means that |
| 496 | * the last piece of the node won't reach the flash media immediately if it |
| 497 | * does not take whole minimal I/O unit. Instead, the node will sit in RAM |
| 498 | * until the write-buffer is synchronized (e.g., by timer). |
| 499 | * |
| 500 | * This function returns zero in case of success and a negative error code in |
| 501 | * case of failure. If the node cannot be written because there is no more |
| 502 | * space in this logical eraseblock, %-ENOSPC is returned. |
| 503 | */ |
| 504 | int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) |
| 505 | { |
| 506 | struct ubifs_info *c = wbuf->c; |
| 507 | int err, written, n, aligned_len = ALIGN(len, 8), offs; |
| 508 | |
| 509 | dbg_io("%d bytes (%s) to wbuf at LEB %d:%d", len, |
| 510 | dbg_ntype(((struct ubifs_ch *)buf)->node_type), wbuf->lnum, |
| 511 | wbuf->offs + wbuf->used); |
| 512 | ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); |
| 513 | ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); |
| 514 | ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); |
| 515 | ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size); |
| 516 | ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); |
| 517 | |
| 518 | if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { |
| 519 | err = -ENOSPC; |
| 520 | goto out; |
| 521 | } |
| 522 | |
| 523 | cancel_wbuf_timer_nolock(wbuf); |
| 524 | |
| 525 | if (c->ro_media) |
| 526 | return -EROFS; |
| 527 | |
| 528 | if (aligned_len <= wbuf->avail) { |
| 529 | /* |
| 530 | * The node is not very large and fits entirely within |
| 531 | * write-buffer. |
| 532 | */ |
| 533 | memcpy(wbuf->buf + wbuf->used, buf, len); |
| 534 | |
| 535 | if (aligned_len == wbuf->avail) { |
| 536 | dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, |
| 537 | wbuf->offs); |
| 538 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, |
| 539 | wbuf->offs, c->min_io_size, |
| 540 | wbuf->dtype); |
| 541 | if (err) |
| 542 | goto out; |
| 543 | |
| 544 | spin_lock(&wbuf->lock); |
| 545 | wbuf->offs += c->min_io_size; |
| 546 | wbuf->avail = c->min_io_size; |
| 547 | wbuf->used = 0; |
| 548 | wbuf->next_ino = 0; |
| 549 | spin_unlock(&wbuf->lock); |
| 550 | } else { |
| 551 | spin_lock(&wbuf->lock); |
| 552 | wbuf->avail -= aligned_len; |
| 553 | wbuf->used += aligned_len; |
| 554 | spin_unlock(&wbuf->lock); |
| 555 | } |
| 556 | |
| 557 | goto exit; |
| 558 | } |
| 559 | |
| 560 | /* |
| 561 | * The node is large enough and does not fit entirely within current |
| 562 | * minimal I/O unit. We have to fill and flush write-buffer and switch |
| 563 | * to the next min. I/O unit. |
| 564 | */ |
| 565 | dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, wbuf->offs); |
| 566 | memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); |
| 567 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, |
| 568 | c->min_io_size, wbuf->dtype); |
| 569 | if (err) |
| 570 | goto out; |
| 571 | |
| 572 | offs = wbuf->offs + c->min_io_size; |
| 573 | len -= wbuf->avail; |
| 574 | aligned_len -= wbuf->avail; |
| 575 | written = wbuf->avail; |
| 576 | |
| 577 | /* |
| 578 | * The remaining data may take more whole min. I/O units, so write the |
| 579 | * remains multiple to min. I/O unit size directly to the flash media. |
| 580 | * We align node length to 8-byte boundary because we anyway flash wbuf |
| 581 | * if the remaining space is less than 8 bytes. |
| 582 | */ |
| 583 | n = aligned_len >> c->min_io_shift; |
| 584 | if (n) { |
| 585 | n <<= c->min_io_shift; |
| 586 | dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs); |
| 587 | err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n, |
| 588 | wbuf->dtype); |
| 589 | if (err) |
| 590 | goto out; |
| 591 | offs += n; |
| 592 | aligned_len -= n; |
| 593 | len -= n; |
| 594 | written += n; |
| 595 | } |
| 596 | |
| 597 | spin_lock(&wbuf->lock); |
| 598 | if (aligned_len) |
| 599 | /* |
| 600 | * And now we have what's left and what does not take whole |
| 601 | * min. I/O unit, so write it to the write-buffer and we are |
| 602 | * done. |
| 603 | */ |
| 604 | memcpy(wbuf->buf, buf + written, len); |
| 605 | |
| 606 | wbuf->offs = offs; |
| 607 | wbuf->used = aligned_len; |
| 608 | wbuf->avail = c->min_io_size - aligned_len; |
| 609 | wbuf->next_ino = 0; |
| 610 | spin_unlock(&wbuf->lock); |
| 611 | |
| 612 | exit: |
| 613 | if (wbuf->sync_callback) { |
| 614 | int free = c->leb_size - wbuf->offs - wbuf->used; |
| 615 | |
| 616 | err = wbuf->sync_callback(c, wbuf->lnum, free, 0); |
| 617 | if (err) |
| 618 | goto out; |
| 619 | } |
| 620 | |
| 621 | if (wbuf->used) |
| 622 | new_wbuf_timer_nolock(wbuf); |
| 623 | |
| 624 | return 0; |
| 625 | |
| 626 | out: |
| 627 | ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", |
| 628 | len, wbuf->lnum, wbuf->offs, err); |
| 629 | dbg_dump_node(c, buf); |
| 630 | dbg_dump_stack(); |
| 631 | dbg_dump_leb(c, wbuf->lnum); |
| 632 | return err; |
| 633 | } |
| 634 | |
| 635 | /** |
| 636 | * ubifs_write_node - write node to the media. |
| 637 | * @c: UBIFS file-system description object |
| 638 | * @buf: the node to write |
| 639 | * @len: node length |
| 640 | * @lnum: logical eraseblock number |
| 641 | * @offs: offset within the logical eraseblock |
| 642 | * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) |
| 643 | * |
| 644 | * This function automatically fills node magic number, assigns sequence |
| 645 | * number, and calculates node CRC checksum. The length of the @buf buffer has |
| 646 | * to be aligned to the minimal I/O unit size. This function automatically |
| 647 | * appends padding node and padding bytes if needed. Returns zero in case of |
| 648 | * success and a negative error code in case of failure. |
| 649 | */ |
| 650 | int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, |
| 651 | int offs, int dtype) |
| 652 | { |
| 653 | int err, buf_len = ALIGN(len, c->min_io_size); |
| 654 | |
| 655 | dbg_io("LEB %d:%d, %s, length %d (aligned %d)", |
| 656 | lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, |
| 657 | buf_len); |
| 658 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
| 659 | ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size); |
| 660 | |
| 661 | if (c->ro_media) |
| 662 | return -EROFS; |
| 663 | |
| 664 | ubifs_prepare_node(c, buf, len, 1); |
| 665 | err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype); |
| 666 | if (err) { |
| 667 | ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", |
| 668 | buf_len, lnum, offs, err); |
| 669 | dbg_dump_node(c, buf); |
| 670 | dbg_dump_stack(); |
| 671 | } |
| 672 | |
| 673 | return err; |
| 674 | } |
| 675 | |
| 676 | /** |
| 677 | * ubifs_read_node_wbuf - read node from the media or write-buffer. |
| 678 | * @wbuf: wbuf to check for un-written data |
| 679 | * @buf: buffer to read to |
| 680 | * @type: node type |
| 681 | * @len: node length |
| 682 | * @lnum: logical eraseblock number |
| 683 | * @offs: offset within the logical eraseblock |
| 684 | * |
| 685 | * This function reads a node of known type and length, checks it and stores |
| 686 | * in @buf. If the node partially or fully sits in the write-buffer, this |
| 687 | * function takes data from the buffer, otherwise it reads the flash media. |
| 688 | * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative |
| 689 | * error code in case of failure. |
| 690 | */ |
| 691 | int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, |
| 692 | int lnum, int offs) |
| 693 | { |
| 694 | const struct ubifs_info *c = wbuf->c; |
| 695 | int err, rlen, overlap; |
| 696 | struct ubifs_ch *ch = buf; |
| 697 | |
| 698 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); |
| 699 | ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
| 700 | ubifs_assert(!(offs & 7) && offs < c->leb_size); |
| 701 | ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); |
| 702 | |
| 703 | spin_lock(&wbuf->lock); |
| 704 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); |
| 705 | if (!overlap) { |
| 706 | /* We may safely unlock the write-buffer and read the data */ |
| 707 | spin_unlock(&wbuf->lock); |
| 708 | return ubifs_read_node(c, buf, type, len, lnum, offs); |
| 709 | } |
| 710 | |
| 711 | /* Don't read under wbuf */ |
| 712 | rlen = wbuf->offs - offs; |
| 713 | if (rlen < 0) |
| 714 | rlen = 0; |
| 715 | |
| 716 | /* Copy the rest from the write-buffer */ |
| 717 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); |
| 718 | spin_unlock(&wbuf->lock); |
| 719 | |
| 720 | if (rlen > 0) { |
| 721 | /* Read everything that goes before write-buffer */ |
| 722 | err = ubi_read(c->ubi, lnum, buf, offs, rlen); |
| 723 | if (err && err != -EBADMSG) { |
| 724 | ubifs_err("failed to read node %d from LEB %d:%d, " |
| 725 | "error %d", type, lnum, offs, err); |
| 726 | dbg_dump_stack(); |
| 727 | return err; |
| 728 | } |
| 729 | } |
| 730 | |
| 731 | if (type != ch->node_type) { |
| 732 | ubifs_err("bad node type (%d but expected %d)", |
| 733 | ch->node_type, type); |
| 734 | goto out; |
| 735 | } |
| 736 | |
Adrian Hunter | 2953e73 | 2008-09-04 16:26:00 +0300 | [diff] [blame] | 737 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 738 | if (err) { |
| 739 | ubifs_err("expected node type %d", type); |
| 740 | return err; |
| 741 | } |
| 742 | |
| 743 | rlen = le32_to_cpu(ch->len); |
| 744 | if (rlen != len) { |
| 745 | ubifs_err("bad node length %d, expected %d", rlen, len); |
| 746 | goto out; |
| 747 | } |
| 748 | |
| 749 | return 0; |
| 750 | |
| 751 | out: |
| 752 | ubifs_err("bad node at LEB %d:%d", lnum, offs); |
| 753 | dbg_dump_node(c, buf); |
| 754 | dbg_dump_stack(); |
| 755 | return -EINVAL; |
| 756 | } |
| 757 | |
| 758 | /** |
| 759 | * ubifs_read_node - read node. |
| 760 | * @c: UBIFS file-system description object |
| 761 | * @buf: buffer to read to |
| 762 | * @type: node type |
| 763 | * @len: node length (not aligned) |
| 764 | * @lnum: logical eraseblock number |
| 765 | * @offs: offset within the logical eraseblock |
| 766 | * |
| 767 | * This function reads a node of known type and and length, checks it and |
| 768 | * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched |
| 769 | * and a negative error code in case of failure. |
| 770 | */ |
| 771 | int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, |
| 772 | int lnum, int offs) |
| 773 | { |
| 774 | int err, l; |
| 775 | struct ubifs_ch *ch = buf; |
| 776 | |
| 777 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); |
| 778 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
| 779 | ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); |
| 780 | ubifs_assert(!(offs & 7) && offs < c->leb_size); |
| 781 | ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); |
| 782 | |
| 783 | err = ubi_read(c->ubi, lnum, buf, offs, len); |
| 784 | if (err && err != -EBADMSG) { |
| 785 | ubifs_err("cannot read node %d from LEB %d:%d, error %d", |
| 786 | type, lnum, offs, err); |
| 787 | return err; |
| 788 | } |
| 789 | |
| 790 | if (type != ch->node_type) { |
| 791 | ubifs_err("bad node type (%d but expected %d)", |
| 792 | ch->node_type, type); |
| 793 | goto out; |
| 794 | } |
| 795 | |
Adrian Hunter | 2953e73 | 2008-09-04 16:26:00 +0300 | [diff] [blame] | 796 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 797 | if (err) { |
| 798 | ubifs_err("expected node type %d", type); |
| 799 | return err; |
| 800 | } |
| 801 | |
| 802 | l = le32_to_cpu(ch->len); |
| 803 | if (l != len) { |
| 804 | ubifs_err("bad node length %d, expected %d", l, len); |
| 805 | goto out; |
| 806 | } |
| 807 | |
| 808 | return 0; |
| 809 | |
| 810 | out: |
| 811 | ubifs_err("bad node at LEB %d:%d", lnum, offs); |
| 812 | dbg_dump_node(c, buf); |
| 813 | dbg_dump_stack(); |
| 814 | return -EINVAL; |
| 815 | } |
| 816 | |
| 817 | /** |
| 818 | * ubifs_wbuf_init - initialize write-buffer. |
| 819 | * @c: UBIFS file-system description object |
| 820 | * @wbuf: write-buffer to initialize |
| 821 | * |
| 822 | * This function initializes write buffer. Returns zero in case of success |
| 823 | * %-ENOMEM in case of failure. |
| 824 | */ |
| 825 | int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) |
| 826 | { |
| 827 | size_t size; |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 828 | ktime_t hardlimit; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 829 | |
| 830 | wbuf->buf = kmalloc(c->min_io_size, GFP_KERNEL); |
| 831 | if (!wbuf->buf) |
| 832 | return -ENOMEM; |
| 833 | |
| 834 | size = (c->min_io_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); |
| 835 | wbuf->inodes = kmalloc(size, GFP_KERNEL); |
| 836 | if (!wbuf->inodes) { |
| 837 | kfree(wbuf->buf); |
| 838 | wbuf->buf = NULL; |
| 839 | return -ENOMEM; |
| 840 | } |
| 841 | |
| 842 | wbuf->used = 0; |
| 843 | wbuf->lnum = wbuf->offs = -1; |
| 844 | wbuf->avail = c->min_io_size; |
| 845 | wbuf->dtype = UBI_UNKNOWN; |
| 846 | wbuf->sync_callback = NULL; |
| 847 | mutex_init(&wbuf->io_mutex); |
| 848 | spin_lock_init(&wbuf->lock); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 849 | wbuf->c = c; |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 850 | wbuf->next_ino = 0; |
| 851 | |
Artem Bityutskiy | f2c5dbd | 2009-05-28 16:24:15 +0300 | [diff] [blame] | 852 | hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
| 853 | wbuf->timer.function = wbuf_timer_callback_nolock; |
| 854 | /* |
| 855 | * Make write-buffer soft limit to be 20% of the hard limit. The |
| 856 | * write-buffer timer is allowed to expire any time between the soft |
| 857 | * and hard limits. |
| 858 | */ |
| 859 | hardlimit = ktime_set(DEFAULT_WBUF_TIMEOUT_SECS, 0); |
| 860 | wbuf->delta = (DEFAULT_WBUF_TIMEOUT_SECS * NSEC_PER_SEC) * 2 / 10; |
| 861 | wbuf->softlimit = ktime_sub_ns(hardlimit, wbuf->delta); |
| 862 | hrtimer_set_expires_range_ns(&wbuf->timer, wbuf->softlimit, |
| 863 | wbuf->delta); |
Artem Bityutskiy | 1e51764 | 2008-07-14 19:08:37 +0300 | [diff] [blame] | 864 | return 0; |
| 865 | } |
| 866 | |
| 867 | /** |
| 868 | * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. |
| 869 | * @wbuf: the write-buffer whereto add |
| 870 | * @inum: the inode number |
| 871 | * |
| 872 | * This function adds an inode number to the inode array of the write-buffer. |
| 873 | */ |
| 874 | void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) |
| 875 | { |
| 876 | if (!wbuf->buf) |
| 877 | /* NOR flash or something similar */ |
| 878 | return; |
| 879 | |
| 880 | spin_lock(&wbuf->lock); |
| 881 | if (wbuf->used) |
| 882 | wbuf->inodes[wbuf->next_ino++] = inum; |
| 883 | spin_unlock(&wbuf->lock); |
| 884 | } |
| 885 | |
| 886 | /** |
| 887 | * wbuf_has_ino - returns if the wbuf contains data from the inode. |
| 888 | * @wbuf: the write-buffer |
| 889 | * @inum: the inode number |
| 890 | * |
| 891 | * This function returns with %1 if the write-buffer contains some data from the |
| 892 | * given inode otherwise it returns with %0. |
| 893 | */ |
| 894 | static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) |
| 895 | { |
| 896 | int i, ret = 0; |
| 897 | |
| 898 | spin_lock(&wbuf->lock); |
| 899 | for (i = 0; i < wbuf->next_ino; i++) |
| 900 | if (inum == wbuf->inodes[i]) { |
| 901 | ret = 1; |
| 902 | break; |
| 903 | } |
| 904 | spin_unlock(&wbuf->lock); |
| 905 | |
| 906 | return ret; |
| 907 | } |
| 908 | |
| 909 | /** |
| 910 | * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. |
| 911 | * @c: UBIFS file-system description object |
| 912 | * @inode: inode to synchronize |
| 913 | * |
| 914 | * This function synchronizes write-buffers which contain nodes belonging to |
| 915 | * @inode. Returns zero in case of success and a negative error code in case of |
| 916 | * failure. |
| 917 | */ |
| 918 | int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) |
| 919 | { |
| 920 | int i, err = 0; |
| 921 | |
| 922 | for (i = 0; i < c->jhead_cnt; i++) { |
| 923 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
| 924 | |
| 925 | if (i == GCHD) |
| 926 | /* |
| 927 | * GC head is special, do not look at it. Even if the |
| 928 | * head contains something related to this inode, it is |
| 929 | * a _copy_ of corresponding on-flash node which sits |
| 930 | * somewhere else. |
| 931 | */ |
| 932 | continue; |
| 933 | |
| 934 | if (!wbuf_has_ino(wbuf, inode->i_ino)) |
| 935 | continue; |
| 936 | |
| 937 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
| 938 | if (wbuf_has_ino(wbuf, inode->i_ino)) |
| 939 | err = ubifs_wbuf_sync_nolock(wbuf); |
| 940 | mutex_unlock(&wbuf->io_mutex); |
| 941 | |
| 942 | if (err) { |
| 943 | ubifs_ro_mode(c, err); |
| 944 | return err; |
| 945 | } |
| 946 | } |
| 947 | return 0; |
| 948 | } |