/** * ubifs_write_node - write node to the media. * @c: UBIFS file-system description object * @buf: the node to write * @len: node length * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) * * This function automatically fills node magic number, assigns sequence * number, and calculates node CRC checksum. The length of the @buf buffer has * to be aligned to the minimal I/O unit size. This function automatically * appends padding node and padding bytes if needed. Returns zero in case of * success and a negative error code in case of failure. */ int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, int offs, int dtype) { int err, buf_len = ALIGN(len, c->min_io_size); dbg_io("LEB %d:%d, %s, length %d (aligned %d)", lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, buf_len); ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size); ubifs_assert(!c->ro_media && !c->ro_mount); ubifs_assert(!c->space_fixup); if (c->ro_error) return -EROFS; ubifs_prepare_node(c, buf, len, 1); err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype); if (err) { ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", buf_len, lnum, offs, err); dbg_dump_node(c, buf); dbg_dump_stack(); } return err; }
/** * ubifs_check_node - check node. * @c: UBIFS file-system description object * @buf: node to check * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * @quiet: print no messages * * This function checks node magic number and CRC checksum. This function also * validates node length to prevent UBIFS from becoming crazy when an attacker * feeds it a file-system image with incorrect nodes. For example, too large * node length in the common header could cause UBIFS to read memory outside of * allocated buffer when checking the CRC checksum. * * This function returns zero in case of success %-EUCLEAN in case of bad CRC * or magic. */ int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, int offs, int quiet) { int err = -EINVAL, type, node_len; uint32_t crc, node_crc, magic; const struct ubifs_ch *ch = buf; ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(!(offs & 7) && offs < c->leb_size); magic = le32_to_cpu(ch->magic); if (magic != UBIFS_NODE_MAGIC) { if (!quiet) ubifs_err("bad magic %#08x, expected %#08x", magic, UBIFS_NODE_MAGIC); err = -EUCLEAN; goto out; } type = ch->node_type; if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { if (!quiet) ubifs_err("bad node type %d", type); goto out; } node_len = le32_to_cpu(ch->len); if (node_len + offs > c->leb_size) goto out_len; if (c->ranges[type].max_len == 0) { if (node_len != c->ranges[type].len) goto out_len; } else if (node_len < c->ranges[type].min_len || node_len > c->ranges[type].max_len) goto out_len; crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); node_crc = le32_to_cpu(ch->crc); if (crc != node_crc) { if (!quiet) ubifs_err("bad CRC: calculated %#08x, read %#08x", crc, node_crc); err = -EUCLEAN; goto out; } return 0; out_len: if (!quiet) ubifs_err("bad node length %d", node_len); out: if (!quiet) { ubifs_err("bad node at LEB %d:%d", lnum, offs); dbg_dump_node(c, buf); dbg_dump_stack(); } return err; }
/** * ubifs_ro_mode - switch UBIFS to read read-only mode. * @c: UBIFS file-system description object * @err: error code which is the reason of switching to R/O mode */ void ubifs_ro_mode(struct ubifs_info *c, int err) { if (!c->ro_media) { c->ro_media = 1; c->no_chk_data_crc = 0; ubifs_warn("switched to read-only mode, error %d", err); dbg_dump_stack(); } }
/** * ubifs_ro_mode - switch UBIFS to read read-only mode. * @c: UBIFS file-system description object * @err: error code which is the reason of switching to R/O mode */ void ubifs_ro_mode(struct ubifs_info *c, int err) { if (!c->ro_error) { c->ro_error = 1; c->no_chk_data_crc = 0; c->vfs_sb->s_flags |= MS_RDONLY; ubifs_warn("switched to read-only mode, error %d", err); dbg_dump_stack(); } }
/** * ubifs_read_node - read node. * @c: UBIFS file-system description object * @buf: buffer to read to * @type: node type * @len: node length (not aligned) * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * * This function reads a node of known type and and length, checks it and * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched * and a negative error code in case of failure. */ int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, int lnum, int offs) { int err, l; struct ubifs_ch *ch = buf; int try_count = 0; dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); ubifs_assert(!(offs & 7) && offs < c->leb_size); ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); try_read: err = ubi_read(c->ubi, lnum, buf, offs, len); if (err && err != -EBADMSG) { ubifs_err("cannot read node %d from LEB %d:%d, error %d", type, lnum, offs, err); return err; } if (type != ch->node_type) { ubifs_err("bad node type (%d but expected %d)", ch->node_type, type); goto out; } err = ubifs_check_node(c, buf, lnum, offs, 0, 0); if (err) { ubifs_err("expected node type %d", type); if(try_count < 3){ try_count++; udelay(100); goto try_read; } else{ return err; } } l = le32_to_cpu(ch->len); if (l != len) { ubifs_err("bad node length %d, expected %d", l, len); goto out; } return 0; out: ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum, offs, ubi_is_mapped(c->ubi, lnum)); dbg_dump_node(c, buf); dbg_dump_stack(); return -EINVAL; }
int ubifs_is_mapped(const struct ubifs_info *c, int lnum) { int err; err = ubi_is_mapped(c->ubi, lnum); if (err < 0) { ubifs_err("ubi_is_mapped failed for LEB %d, error %d", lnum, err); dbg_dump_stack(); } return err; }
/** * ubifs_read_node - read node. * @c: UBIFS file-system description object * @buf: buffer to read to * @type: node type * @len: node length (not aligned) * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * * This function reads a node of known type and and length, checks it and * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched * and a negative error code in case of failure. */ int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, int lnum, int offs) { int err, l; struct ubifs_ch *ch = buf; #if defined(FEATURE_UBIFS_PERF_INDEX) unsigned long long time1 = sched_clock(); #endif dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); ubifs_assert(!(offs & 7) && offs < c->leb_size); ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); err = ubifs_leb_read(c, lnum, buf, offs, len, 0); if (err && err != -EBADMSG) return err; if (type != ch->node_type) { ubifs_err("bad node type (%d but expected %d)", ch->node_type, type); goto out; } err = ubifs_check_node(c, buf, lnum, offs, 0, 0); if (err) { ubifs_err("expected node type %d", type); return err; } l = le32_to_cpu(ch->len); if (l != len) { ubifs_err("bad node length %d, expected %d", l, len); goto out; } #if defined(FEATURE_UBIFS_PERF_INDEX) if(type == UBIFS_DATA_NODE) { ubifs_perf_lrcount(sched_clock() - time1, len); } #endif return 0; out: ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum, offs, ubi_is_mapped(c->ubi, lnum)); dbg_dump_node(c, buf); dbg_dump_stack(); return -EINVAL; }
int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, int len, int even_ebadmsg) { int err; err = ubi_leb_read(c->ubi, lnum, buf, offs, len, 0); /* * In case of %-EBADMSG print the error message only if the * @even_ebadmsg is true. */ if (err && (err != -EBADMSG || even_ebadmsg)) { ubifs_err("reading %d bytes from LEB %d:%d failed, error %d", len, lnum, offs, err); dbg_dump_stack(); } return err; }
int ubifs_leb_map(struct ubifs_info *c, int lnum) { int err; ubifs_assert(!c->ro_media && !c->ro_mount); if (c->ro_error) return -EROFS; if (!dbg_is_tst_rcvry(c)) err = ubi_leb_map(c->ubi, lnum); else err = dbg_leb_map(c, lnum); if (err) { ubifs_err("mapping LEB %d failed, error %d", lnum, err); ubifs_ro_mode(c, err); dbg_dump_stack(); } return err; }
int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len) { int err; ubifs_assert(!c->ro_media && !c->ro_mount); if (c->ro_error) return -EROFS; if (!dbg_is_tst_rcvry(c)) err = ubi_leb_change(c->ubi, lnum, buf, len); else err = dbg_leb_change(c, lnum, buf, len); if (err) { ubifs_err("changing %d bytes in LEB %d failed, error %d", len, lnum, err); ubifs_ro_mode(c, err); dbg_dump_stack(); } return err; }
/** * ubifs_wbuf_sync_nolock - synchronize write-buffer. * @wbuf: write-buffer to synchronize * * This function synchronizes write-buffer @buf and returns zero in case of * success or a negative error code in case of failure. */ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) { struct ubifs_info *c = wbuf->c; int err, dirt; cancel_wbuf_timer_nolock(wbuf); if (!wbuf->used || wbuf->lnum == -1) /* Write-buffer is empty or not seeked */ return 0; dbg_io("LEB %d:%d, %d bytes", wbuf->lnum, wbuf->offs, wbuf->used); ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY)); ubifs_assert(!(wbuf->avail & 7)); ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size); if (c->ro_media) return -EROFS; ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail); err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, c->min_io_size, wbuf->dtype); if (err) { ubifs_err("cannot write %d bytes to LEB %d:%d", c->min_io_size, wbuf->lnum, wbuf->offs); dbg_dump_stack(); return err; } dirt = wbuf->avail; spin_lock(&wbuf->lock); wbuf->offs += c->min_io_size; wbuf->avail = c->min_io_size; wbuf->used = 0; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); if (wbuf->sync_callback) err = wbuf->sync_callback(c, wbuf->lnum, c->leb_size - wbuf->offs, dirt); return err; }
int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, int len, int dtype) { int err; ubifs_assert(!c->ro_media && !c->ro_mount); if (c->ro_error) return -EROFS; if (!dbg_is_tst_rcvry(c)) err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype); else err = dbg_leb_write(c, lnum, buf, offs, len, dtype); if (err) { ubifs_err("writing %d bytes to LEB %d:%d failed, error %d", len, lnum, offs, err); ubifs_ro_mode(c, err); dbg_dump_stack(); } return err; }
/** * make_reservation - reserve journal space. * @c: UBIFS file-system description object * @jhead: journal head * @len: how many bytes to reserve * * This function makes space reservation in journal head @jhead. The function * takes the commit lock and locks the journal head, and the caller has to * unlock the head and finish the reservation with 'finish_reservation()'. * Returns zero in case of success and a negative error code in case of * failure. * * Note, the journal head may be unlocked as soon as the data is written, while * the commit lock has to be released after the data has been added to the * TNC. */ static int make_reservation(struct ubifs_info *c, int jhead, int len) { int err, cmt_retries = 0, nospc_retries = 0; ubifs_assert(len <= c->dark_wm); again: down_read(&c->commit_sem); err = reserve_space(c, jhead, len); if (!err) return 0; up_read(&c->commit_sem); if (err == -ENOSPC) { /* * GC could not make any progress. We should try to commit * once because it could make some dirty space and GC would * make progress, so make the error -EAGAIN so that the below * will commit and re-try. */ if (nospc_retries++ < 2) { dbg_jrn("no space, retry"); err = -EAGAIN; } /* * This means that the budgeting is incorrect. We always have * to be able to write to the media, because all operations are * budgeted. Deletions are not budgeted, though, but we reserve * an extra LEB for them. */ } if (err != -EAGAIN) goto out; /* * -EAGAIN means that the journal is full or too large, or the above * code wants to do one commit. Do this and re-try. */ if (cmt_retries > 128) { /* * This should not happen unless the journal size limitations * are too tough. */ ubifs_err("stuck in space allocation"); err = -ENOSPC; goto out; } else if (cmt_retries > 32) ubifs_warn("too many space allocation re-tries (%d)", cmt_retries); dbg_jrn("-EAGAIN, commit and retry (retried %d times)", cmt_retries); cmt_retries += 1; err = ubifs_run_commit(c); if (err) return err; goto again; out: ubifs_err("cannot reserve %d bytes in jhead %d, error %d", len, jhead, err); if (err == -ENOSPC) { /* This are some budgeting problems, print useful information */ down_write(&c->commit_sem); spin_lock(&c->space_lock); dbg_dump_stack(); dbg_dump_budg(c); spin_unlock(&c->space_lock); dbg_dump_lprops(c); cmt_retries = dbg_check_lprops(c); up_write(&c->commit_sem); } return err; }
/** * ubifs_read_node_wbuf - read node from the media or write-buffer. * @wbuf: wbuf to check for un-written data * @buf: buffer to read to * @type: node type * @len: node length * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * * This function reads a node of known type and length, checks it and stores * in @buf. If the node partially or fully sits in the write-buffer, this * function takes data from the buffer, otherwise it reads the flash media. * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative * error code in case of failure. */ int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, int lnum, int offs) { const struct ubifs_info *c = wbuf->c; int err, rlen, overlap; struct ubifs_ch *ch = buf; #if defined(FEATURE_UBIFS_PERF_INDEX) unsigned long long time1 = sched_clock(); int log_len = 0; #endif dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(!(offs & 7) && offs < c->leb_size); ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); spin_lock(&wbuf->lock); overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); if (!overlap) { /* We may safely unlock the write-buffer and read the data */ spin_unlock(&wbuf->lock); return ubifs_read_node(c, buf, type, len, lnum, offs); } /* Don't read under wbuf */ rlen = wbuf->offs - offs; if (rlen < 0) rlen = 0; /* Copy the rest from the write-buffer */ memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); spin_unlock(&wbuf->lock); if (rlen > 0) { /* Read everything that goes before write-buffer */ err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0); if (err && err != -EBADMSG) return err; } if (type != ch->node_type) { ubifs_err("bad node type (%d but expected %d)", ch->node_type, type); goto out; } err = ubifs_check_node(c, buf, lnum, offs, 0, 0); if (err) { ubifs_err("expected node type %d", type); return err; } rlen = le32_to_cpu(ch->len); if (rlen != len) { ubifs_err("bad node length %d, expected %d", rlen, len); goto out; } #if defined(FEATURE_UBIFS_PERF_INDEX) if(log_len > 0) { ubifs_perf_lrcount(sched_clock() - time1, log_len); } #endif return 0; out: ubifs_err("bad node at LEB %d:%d", lnum, offs); dbg_dump_node(c, buf); dbg_dump_stack(); return -EINVAL; }
/** * ubifs_wbuf_write_nolock - write data to flash via write-buffer. * @wbuf: write-buffer * @buf: node to write * @len: node length * * This function writes data to flash via write-buffer @wbuf. This means that * the last piece of the node won't reach the flash media immediately if it * does not take whole max. write unit (@c->max_write_size). Instead, the node * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or * because more data are appended to the write-buffer). * * This function returns zero in case of success and a negative error code in * case of failure. If the node cannot be written because there is no more * space in this logical eraseblock, %-ENOSPC is returned. */ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) { struct ubifs_info *c = wbuf->c; int err, written, n, aligned_len = ALIGN(len, 8); dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, dbg_ntype(((struct ubifs_ch *)buf)->node_type), dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); ubifs_assert(wbuf->avail > 0 && wbuf->avail <= wbuf->size); ubifs_assert(wbuf->size >= c->min_io_size); ubifs_assert(wbuf->size <= c->max_write_size); ubifs_assert(wbuf->size % c->min_io_size == 0); ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); ubifs_assert(!c->ro_media && !c->ro_mount); ubifs_assert(!c->space_fixup); if (c->leb_size - wbuf->offs >= c->max_write_size) ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { err = -ENOSPC; goto out; } cancel_wbuf_timer_nolock(wbuf); if (c->ro_error) return -EROFS; if (aligned_len <= wbuf->avail) { /* * The node is not very large and fits entirely within * write-buffer. */ memcpy(wbuf->buf + wbuf->used, buf, len); if (aligned_len == wbuf->avail) { dbg_io("flush jhead %s wbuf to LEB %d:%d", dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); #if defined(FEATURE_UBIFS_PERF_INDEX) if(wbuf->jhead == DATAHD) err = ubifs_leb_write_log(c, wbuf->lnum, wbuf->buf, wbuf->offs, wbuf->size); else #endif err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, wbuf->size); if (err) goto out; wbuf->w_count += wbuf->size; //MTK spin_lock(&wbuf->lock); wbuf->offs += wbuf->size; if (c->leb_size - wbuf->offs >= c->max_write_size) wbuf->size = c->max_write_size; else wbuf->size = c->leb_size - wbuf->offs; wbuf->avail = wbuf->size; wbuf->used = 0; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); } else { spin_lock(&wbuf->lock); wbuf->avail -= aligned_len; wbuf->used += aligned_len; spin_unlock(&wbuf->lock); } goto exit; } written = 0; if (wbuf->used) { /* * The node is large enough and does not fit entirely within * current available space. We have to fill and flush * write-buffer and switch to the next max. write unit. */ dbg_io("flush jhead %s wbuf to LEB %d:%d", dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); #if defined(FEATURE_UBIFS_PERF_INDEX) if(wbuf->jhead == DATAHD) err = ubifs_leb_write_log(c, wbuf->lnum, wbuf->buf, wbuf->offs, wbuf->size); else #endif err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, wbuf->size); if (err) goto out; wbuf->w_count += wbuf->size; //MTK wbuf->offs += wbuf->size; len -= wbuf->avail; aligned_len -= wbuf->avail; written += wbuf->avail; } else if (wbuf->offs & (c->max_write_size - 1)) { /* * The write-buffer offset is not aligned to * @c->max_write_size and @wbuf->size is less than * @c->max_write_size. Write @wbuf->size bytes to make sure the * following writes are done in optimal @c->max_write_size * chunks. */ dbg_io("write %d bytes to LEB %d:%d", wbuf->size, wbuf->lnum, wbuf->offs); #if defined(FEATURE_UBIFS_PERF_INDEX) if(wbuf->jhead == DATAHD) err = ubifs_leb_write_log(c, wbuf->lnum, wbuf->buf, wbuf->offs, wbuf->size); else #endif err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs, wbuf->size); if (err) goto out; wbuf->w_count += wbuf->size; //MTK wbuf->offs += wbuf->size; len -= wbuf->size; aligned_len -= wbuf->size; written += wbuf->size; } /* * The remaining data may take more whole max. write units, so write the * remains multiple to max. write unit size directly to the flash media. * We align node length to 8-byte boundary because we anyway flash wbuf * if the remaining space is less than 8 bytes. */ n = aligned_len >> c->max_write_shift; if (n) { n <<= c->max_write_shift; dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, wbuf->offs); #if defined(FEATURE_UBIFS_PERF_INDEX) if(wbuf->jhead == DATAHD) err = ubifs_leb_write_log(c, wbuf->lnum, buf + written, wbuf->offs, n); else #endif err = ubifs_leb_write(c, wbuf->lnum, buf + written, wbuf->offs, n); if (err) goto out; wbuf->w_count += n; //MTK wbuf->offs += n; aligned_len -= n; len -= n; written += n; } spin_lock(&wbuf->lock); if (aligned_len) /* * And now we have what's left and what does not take whole * max. write unit, so write it to the write-buffer and we are * done. */ memcpy(wbuf->buf, buf + written, len); if (c->leb_size - wbuf->offs >= c->max_write_size) wbuf->size = c->max_write_size; else wbuf->size = c->leb_size - wbuf->offs; wbuf->avail = wbuf->size - aligned_len; wbuf->used = aligned_len; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); exit: if (wbuf->sync_callback) { int free = c->leb_size - wbuf->offs - wbuf->used; err = wbuf->sync_callback(c, wbuf->lnum, free, 0); if (err) goto out; } if (wbuf->used) new_wbuf_timer_nolock(wbuf); return 0; out: ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", len, wbuf->lnum, wbuf->offs, err); dbg_dump_node(c, buf); dbg_dump_stack(); dbg_dump_leb(c, wbuf->lnum); return err; }
/** * ubifs_wbuf_sync_nolock - synchronize write-buffer. * @wbuf: write-buffer to synchronize * * This function synchronizes write-buffer @buf and returns zero in case of * success or a negative error code in case of failure. * * Note, although write-buffers are of @c->max_write_size, this function does * not necessarily writes all @c->max_write_size bytes to the flash. Instead, * if the write-buffer is only partially filled with data, only the used part * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized. * This way we waste less space. */ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) { struct ubifs_info *c = wbuf->c; int err, dirt, sync_len; cancel_wbuf_timer_nolock(wbuf); if (!wbuf->used || wbuf->lnum == -1) /* Write-buffer is empty or not seeked */ return 0; dbg_io("LEB %d:%d, %d bytes, jhead %s", wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); ubifs_assert(!(wbuf->avail & 7)); ubifs_assert(wbuf->offs + wbuf->size <= c->leb_size); ubifs_assert(wbuf->size >= c->min_io_size); ubifs_assert(wbuf->size <= c->max_write_size); ubifs_assert(wbuf->size % c->min_io_size == 0); ubifs_assert(!c->ro_media && !c->ro_mount); if (c->leb_size - wbuf->offs >= c->max_write_size) ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); if (c->ro_error) return -EROFS; /* * Do not write whole write buffer but write only the minimum necessary * amount of min. I/O units. */ sync_len = ALIGN(wbuf->used, c->min_io_size); dirt = sync_len - wbuf->used; if (dirt) ubifs_pad(c, wbuf->buf + wbuf->used, dirt); err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len, wbuf->dtype); if (err) { ubifs_err("cannot write %d bytes to LEB %d:%d", sync_len, wbuf->lnum, wbuf->offs); dbg_dump_stack(); return err; } spin_lock(&wbuf->lock); wbuf->offs += sync_len; /* * Now @wbuf->offs is not necessarily aligned to @c->max_write_size. * But our goal is to optimize writes and make sure we write in * @c->max_write_size chunks and to @c->max_write_size-aligned offset. * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make * sure that @wbuf->offs + @wbuf->size is aligned to * @c->max_write_size. This way we make sure that after next * write-buffer flush we are again at the optimal offset (aligned to * @c->max_write_size). */ if (c->leb_size - wbuf->offs < c->max_write_size) wbuf->size = c->leb_size - wbuf->offs; else if (wbuf->offs & (c->max_write_size - 1)) wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; else wbuf->size = c->max_write_size; wbuf->avail = wbuf->size; wbuf->used = 0; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); if (wbuf->sync_callback) err = wbuf->sync_callback(c, wbuf->lnum, c->leb_size - wbuf->offs, dirt); return err; }
/** * ubifs_read_node_wbuf - read node from the media or write-buffer. * @wbuf: wbuf to check for un-written data * @buf: buffer to read to * @type: node type * @len: node length * @lnum: logical eraseblock number * @offs: offset within the logical eraseblock * * This function reads a node of known type and length, checks it and stores * in @buf. If the node partially or fully sits in the write-buffer, this * function takes data from the buffer, otherwise it reads the flash media. * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative * error code in case of failure. */ int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, int lnum, int offs) { const struct ubifs_info *c = wbuf->c; int err, rlen, overlap; struct ubifs_ch *ch = buf; dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); ubifs_assert(!(offs & 7) && offs < c->leb_size); ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); spin_lock(&wbuf->lock); overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); if (!overlap) { /* We may safely unlock the write-buffer and read the data */ spin_unlock(&wbuf->lock); return ubifs_read_node(c, buf, type, len, lnum, offs); } /* Don't read under wbuf */ rlen = wbuf->offs - offs; if (rlen < 0) rlen = 0; /* Copy the rest from the write-buffer */ memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); spin_unlock(&wbuf->lock); if (rlen > 0) { /* Read everything that goes before write-buffer */ err = ubi_read(c->ubi, lnum, buf, offs, rlen); if (err && err != -EBADMSG) { ubifs_err("failed to read node %d from LEB %d:%d, " "error %d", type, lnum, offs, err); dbg_dump_stack(); return err; } } if (type != ch->node_type) { ubifs_err("bad node type (%d but expected %d)", ch->node_type, type); goto out; } err = ubifs_check_node(c, buf, lnum, offs, 0, 0); if (err) { ubifs_err("expected node type %d", type); return err; } rlen = le32_to_cpu(ch->len); if (rlen != len) { ubifs_err("bad node length %d, expected %d", rlen, len); goto out; } return 0; out: ubifs_err("bad node at LEB %d:%d", lnum, offs); dbg_dump_node(c, buf); dbg_dump_stack(); return -EINVAL; }
/** * ubifs_wbuf_write_nolock - write data to flash via write-buffer. * @wbuf: write-buffer * @buf: node to write * @len: node length * * This function writes data to flash via write-buffer @wbuf. This means that * the last piece of the node won't reach the flash media immediately if it * does not take whole minimal I/O unit. Instead, the node will sit in RAM * until the write-buffer is synchronized (e.g., by timer). * * This function returns zero in case of success and a negative error code in * case of failure. If the node cannot be written because there is no more * space in this logical eraseblock, %-ENOSPC is returned. */ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) { struct ubifs_info *c = wbuf->c; int err, written, n, aligned_len = ALIGN(len, 8), offs; dbg_io("%d bytes (%s) to wbuf at LEB %d:%d", len, dbg_ntype(((struct ubifs_ch *)buf)->node_type), wbuf->lnum, wbuf->offs + wbuf->used); ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size); ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { err = -ENOSPC; goto out; } cancel_wbuf_timer_nolock(wbuf); if (c->ro_media) return -EROFS; if (aligned_len <= wbuf->avail) { /* * The node is not very large and fits entirely within * write-buffer. */ memcpy(wbuf->buf + wbuf->used, buf, len); if (aligned_len == wbuf->avail) { dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, wbuf->offs); err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, c->min_io_size, wbuf->dtype); if (err) goto out; spin_lock(&wbuf->lock); wbuf->offs += c->min_io_size; wbuf->avail = c->min_io_size; wbuf->used = 0; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); } else { spin_lock(&wbuf->lock); wbuf->avail -= aligned_len; wbuf->used += aligned_len; spin_unlock(&wbuf->lock); } goto exit; } /* * The node is large enough and does not fit entirely within current * minimal I/O unit. We have to fill and flush write-buffer and switch * to the next min. I/O unit. */ dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, wbuf->offs); memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, c->min_io_size, wbuf->dtype); if (err) goto out; offs = wbuf->offs + c->min_io_size; len -= wbuf->avail; aligned_len -= wbuf->avail; written = wbuf->avail; /* * The remaining data may take more whole min. I/O units, so write the * remains multiple to min. I/O unit size directly to the flash media. * We align node length to 8-byte boundary because we anyway flash wbuf * if the remaining space is less than 8 bytes. */ n = aligned_len >> c->min_io_shift; if (n) { n <<= c->min_io_shift; dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs); err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n, wbuf->dtype); if (err) goto out; offs += n; aligned_len -= n; len -= n; written += n; } spin_lock(&wbuf->lock); if (aligned_len) /* * And now we have what's left and what does not take whole * min. I/O unit, so write it to the write-buffer and we are * done. */ memcpy(wbuf->buf, buf + written, len); wbuf->offs = offs; wbuf->used = aligned_len; wbuf->avail = c->min_io_size - aligned_len; wbuf->next_ino = 0; spin_unlock(&wbuf->lock); exit: if (wbuf->sync_callback) { int free = c->leb_size - wbuf->offs - wbuf->used; err = wbuf->sync_callback(c, wbuf->lnum, free, 0); if (err) goto out; } if (wbuf->used) new_wbuf_timer_nolock(wbuf); return 0; out: ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", len, wbuf->lnum, wbuf->offs, err); dbg_dump_node(c, buf); dbg_dump_stack(); dbg_dump_leb(c, wbuf->lnum); return err; }