diff options
Diffstat (limited to 'qemu/roms/u-boot/fs/ubifs/recovery.c')
| -rw-r--r-- | qemu/roms/u-boot/fs/ubifs/recovery.c | 1225 |
1 files changed, 0 insertions, 1225 deletions
diff --git a/qemu/roms/u-boot/fs/ubifs/recovery.c b/qemu/roms/u-boot/fs/ubifs/recovery.c deleted file mode 100644 index 744465005..000000000 --- a/qemu/roms/u-boot/fs/ubifs/recovery.c +++ /dev/null @@ -1,1225 +0,0 @@ -/* - * This file is part of UBIFS. - * - * Copyright (C) 2006-2008 Nokia Corporation - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - * - * Authors: Adrian Hunter - * Artem Bityutskiy (Битюцкий Артём) - */ - -/* - * This file implements functions needed to recover from unclean un-mounts. - * When UBIFS is mounted, it checks a flag on the master node to determine if - * an un-mount was completed sucessfully. If not, the process of mounting - * incorparates additional checking and fixing of on-flash data structures. - * UBIFS always cleans away all remnants of an unclean un-mount, so that - * errors do not accumulate. However UBIFS defers recovery if it is mounted - * read-only, and the flash is not modified in that case. - */ - -#include "ubifs.h" - -/** - * is_empty - determine whether a buffer is empty (contains all 0xff). - * @buf: buffer to clean - * @len: length of buffer - * - * This function returns %1 if the buffer is empty (contains all 0xff) otherwise - * %0 is returned. - */ -static int is_empty(void *buf, int len) -{ - uint8_t *p = buf; - int i; - - for (i = 0; i < len; i++) - if (*p++ != 0xff) - return 0; - return 1; -} - -/** - * get_master_node - get the last valid master node allowing for corruption. - * @c: UBIFS file-system description object - * @lnum: LEB number - * @pbuf: buffer containing the LEB read, is returned here - * @mst: master node, if found, is returned here - * @cor: corruption, if found, is returned here - * - * This function allocates a buffer, reads the LEB into it, and finds and - * returns the last valid master node allowing for one area of corruption. - * The corrupt area, if there is one, must be consistent with the assumption - * that it is the result of an unclean unmount while the master node was being - * written. Under those circumstances, it is valid to use the previously written - * master node. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf, - struct ubifs_mst_node **mst, void **cor) -{ - const int sz = c->mst_node_alsz; - int err, offs, len; - void *sbuf, *buf; - - sbuf = vmalloc(c->leb_size); - if (!sbuf) - return -ENOMEM; - - err = ubi_read(c->ubi, lnum, sbuf, 0, c->leb_size); - if (err && err != -EBADMSG) - goto out_free; - - /* Find the first position that is definitely not a node */ - offs = 0; - buf = sbuf; - len = c->leb_size; - while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) { - struct ubifs_ch *ch = buf; - - if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) - break; - offs += sz; - buf += sz; - len -= sz; - } - /* See if there was a valid master node before that */ - if (offs) { - int ret; - - offs -= sz; - buf -= sz; - len += sz; - ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); - if (ret != SCANNED_A_NODE && offs) { - /* Could have been corruption so check one place back */ - offs -= sz; - buf -= sz; - len += sz; - ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); - if (ret != SCANNED_A_NODE) - /* - * We accept only one area of corruption because - * we are assuming that it was caused while - * trying to write a master node. - */ - goto out_err; - } - if (ret == SCANNED_A_NODE) { - struct ubifs_ch *ch = buf; - - if (ch->node_type != UBIFS_MST_NODE) - goto out_err; - dbg_rcvry("found a master node at %d:%d", lnum, offs); - *mst = buf; - offs += sz; - buf += sz; - len -= sz; - } - } - /* Check for corruption */ - if (offs < c->leb_size) { - if (!is_empty(buf, min_t(int, len, sz))) { - *cor = buf; - dbg_rcvry("found corruption at %d:%d", lnum, offs); - } - offs += sz; - buf += sz; - len -= sz; - } - /* Check remaining empty space */ - if (offs < c->leb_size) - if (!is_empty(buf, len)) - goto out_err; - *pbuf = sbuf; - return 0; - -out_err: - err = -EINVAL; -out_free: - vfree(sbuf); - *mst = NULL; - *cor = NULL; - return err; -} - -/** - * write_rcvrd_mst_node - write recovered master node. - * @c: UBIFS file-system description object - * @mst: master node - * - * This function returns %0 on success and a negative error code on failure. - */ -static int write_rcvrd_mst_node(struct ubifs_info *c, - struct ubifs_mst_node *mst) -{ - int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz; - __le32 save_flags; - - dbg_rcvry("recovery"); - - save_flags = mst->flags; - mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY); - - ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1); - err = ubi_leb_change(c->ubi, lnum, mst, sz, UBI_SHORTTERM); - if (err) - goto out; - err = ubi_leb_change(c->ubi, lnum + 1, mst, sz, UBI_SHORTTERM); - if (err) - goto out; -out: - mst->flags = save_flags; - return err; -} - -/** - * ubifs_recover_master_node - recover the master node. - * @c: UBIFS file-system description object - * - * This function recovers the master node from corruption that may occur due to - * an unclean unmount. - * - * This function returns %0 on success and a negative error code on failure. - */ -int ubifs_recover_master_node(struct ubifs_info *c) -{ - void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL; - struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst; - const int sz = c->mst_node_alsz; - int err, offs1, offs2; - - dbg_rcvry("recovery"); - - err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1); - if (err) - goto out_free; - - err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2); - if (err) - goto out_free; - - if (mst1) { - offs1 = (void *)mst1 - buf1; - if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) && - (offs1 == 0 && !cor1)) { - /* - * mst1 was written by recovery at offset 0 with no - * corruption. - */ - dbg_rcvry("recovery recovery"); - mst = mst1; - } else if (mst2) { - offs2 = (void *)mst2 - buf2; - if (offs1 == offs2) { - /* Same offset, so must be the same */ - if (memcmp((void *)mst1 + UBIFS_CH_SZ, - (void *)mst2 + UBIFS_CH_SZ, - UBIFS_MST_NODE_SZ - UBIFS_CH_SZ)) - goto out_err; - mst = mst1; - } else if (offs2 + sz == offs1) { - /* 1st LEB was written, 2nd was not */ - if (cor1) - goto out_err; - mst = mst1; - } else if (offs1 == 0 && offs2 + sz >= c->leb_size) { - /* 1st LEB was unmapped and written, 2nd not */ - if (cor1) - goto out_err; - mst = mst1; - } else - goto out_err; - } else { - /* - * 2nd LEB was unmapped and about to be written, so - * there must be only one master node in the first LEB - * and no corruption. - */ - if (offs1 != 0 || cor1) - goto out_err; - mst = mst1; - } - } else { - if (!mst2) - goto out_err; - /* - * 1st LEB was unmapped and about to be written, so there must - * be no room left in 2nd LEB. - */ - offs2 = (void *)mst2 - buf2; - if (offs2 + sz + sz <= c->leb_size) - goto out_err; - mst = mst2; - } - - dbg_rcvry("recovered master node from LEB %d", - (mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1)); - - memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ); - - if ((c->vfs_sb->s_flags & MS_RDONLY)) { - /* Read-only mode. Keep a copy for switching to rw mode */ - c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL); - if (!c->rcvrd_mst_node) { - err = -ENOMEM; - goto out_free; - } - memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ); - } - - vfree(buf2); - vfree(buf1); - - return 0; - -out_err: - err = -EINVAL; -out_free: - ubifs_err("failed to recover master node"); - if (mst1) { - dbg_err("dumping first master node"); - dbg_dump_node(c, mst1); - } - if (mst2) { - dbg_err("dumping second master node"); - dbg_dump_node(c, mst2); - } - vfree(buf2); - vfree(buf1); - return err; -} - -/** - * ubifs_write_rcvrd_mst_node - write the recovered master node. - * @c: UBIFS file-system description object - * - * This function writes the master node that was recovered during mounting in - * read-only mode and must now be written because we are remounting rw. - * - * This function returns %0 on success and a negative error code on failure. - */ -int ubifs_write_rcvrd_mst_node(struct ubifs_info *c) -{ - int err; - - if (!c->rcvrd_mst_node) - return 0; - c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); - c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); - err = write_rcvrd_mst_node(c, c->rcvrd_mst_node); - if (err) - return err; - kfree(c->rcvrd_mst_node); - c->rcvrd_mst_node = NULL; - return 0; -} - -/** - * is_last_write - determine if an offset was in the last write to a LEB. - * @c: UBIFS file-system description object - * @buf: buffer to check - * @offs: offset to check - * - * This function returns %1 if @offs was in the last write to the LEB whose data - * is in @buf, otherwise %0 is returned. The determination is made by checking - * for subsequent empty space starting from the next min_io_size boundary (or a - * bit less than the common header size if min_io_size is one). - */ -static int is_last_write(const struct ubifs_info *c, void *buf, int offs) -{ - int empty_offs; - int check_len; - uint8_t *p; - - if (c->min_io_size == 1) { - check_len = c->leb_size - offs; - p = buf + check_len; - for (; check_len > 0; check_len--) - if (*--p != 0xff) - break; - /* - * 'check_len' is the size of the corruption which cannot be - * more than the size of 1 node if it was caused by an unclean - * unmount. - */ - if (check_len > UBIFS_MAX_NODE_SZ) - return 0; - return 1; - } - - /* - * Round up to the next c->min_io_size boundary i.e. 'offs' is in the - * last wbuf written. After that should be empty space. - */ - empty_offs = ALIGN(offs + 1, c->min_io_size); - check_len = c->leb_size - empty_offs; - p = buf + empty_offs - offs; - - for (; check_len > 0; check_len--) - if (*p++ != 0xff) - return 0; - return 1; -} - -/** - * clean_buf - clean the data from an LEB sitting in a buffer. - * @c: UBIFS file-system description object - * @buf: buffer to clean - * @lnum: LEB number to clean - * @offs: offset from which to clean - * @len: length of buffer - * - * This function pads up to the next min_io_size boundary (if there is one) and - * sets empty space to all 0xff. @buf, @offs and @len are updated to the next - * min_io_size boundary (if there is one). - */ -static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, - int *offs, int *len) -{ - int empty_offs, pad_len; - - lnum = lnum; - dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs); - - if (c->min_io_size == 1) { - memset(*buf, 0xff, c->leb_size - *offs); - return; - } - - ubifs_assert(!(*offs & 7)); - empty_offs = ALIGN(*offs, c->min_io_size); - pad_len = empty_offs - *offs; - ubifs_pad(c, *buf, pad_len); - *offs += pad_len; - *buf += pad_len; - *len -= pad_len; - memset(*buf, 0xff, c->leb_size - empty_offs); -} - -/** - * no_more_nodes - determine if there are no more nodes in a buffer. - * @c: UBIFS file-system description object - * @buf: buffer to check - * @len: length of buffer - * @lnum: LEB number of the LEB from which @buf was read - * @offs: offset from which @buf was read - * - * This function ensures that the corrupted node at @offs is the last thing - * written to a LEB. This function returns %1 if more data is not found and - * %0 if more data is found. - */ -static int no_more_nodes(const struct ubifs_info *c, void *buf, int len, - int lnum, int offs) -{ - struct ubifs_ch *ch = buf; - int skip, dlen = le32_to_cpu(ch->len); - - /* Check for empty space after the corrupt node's common header */ - skip = ALIGN(offs + UBIFS_CH_SZ, c->min_io_size) - offs; - if (is_empty(buf + skip, len - skip)) - return 1; - /* - * The area after the common header size is not empty, so the common - * header must be intact. Check it. - */ - if (ubifs_check_node(c, buf, lnum, offs, 1, 0) != -EUCLEAN) { - dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs); - return 0; - } - /* Now we know the corrupt node's length we can skip over it */ - skip = ALIGN(offs + dlen, c->min_io_size) - offs; - /* After which there should be empty space */ - if (is_empty(buf + skip, len - skip)) - return 1; - dbg_rcvry("unexpected data at %d:%d", lnum, offs + skip); - return 0; -} - -/** - * fix_unclean_leb - fix an unclean LEB. - * @c: UBIFS file-system description object - * @sleb: scanned LEB information - * @start: offset where scan started - */ -static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb, - int start) -{ - int lnum = sleb->lnum, endpt = start; - - /* Get the end offset of the last node we are keeping */ - if (!list_empty(&sleb->nodes)) { - struct ubifs_scan_node *snod; - - snod = list_entry(sleb->nodes.prev, - struct ubifs_scan_node, list); - endpt = snod->offs + snod->len; - } - - if ((c->vfs_sb->s_flags & MS_RDONLY) && !c->remounting_rw) { - /* Add to recovery list */ - struct ubifs_unclean_leb *ucleb; - - dbg_rcvry("need to fix LEB %d start %d endpt %d", - lnum, start, sleb->endpt); - ucleb = kzalloc(sizeof(struct ubifs_unclean_leb), GFP_NOFS); - if (!ucleb) - return -ENOMEM; - ucleb->lnum = lnum; - ucleb->endpt = endpt; - list_add_tail(&ucleb->list, &c->unclean_leb_list); - } - return 0; -} - -/** - * drop_incomplete_group - drop nodes from an incomplete group. - * @sleb: scanned LEB information - * @offs: offset of dropped nodes is returned here - * - * This function returns %1 if nodes are dropped and %0 otherwise. - */ -static int drop_incomplete_group(struct ubifs_scan_leb *sleb, int *offs) -{ - int dropped = 0; - - while (!list_empty(&sleb->nodes)) { - struct ubifs_scan_node *snod; - struct ubifs_ch *ch; - - snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, - list); - ch = snod->node; - if (ch->group_type != UBIFS_IN_NODE_GROUP) - return dropped; - dbg_rcvry("dropping node at %d:%d", sleb->lnum, snod->offs); - *offs = snod->offs; - list_del(&snod->list); - kfree(snod); - sleb->nodes_cnt -= 1; - dropped = 1; - } - return dropped; -} - -/** - * ubifs_recover_leb - scan and recover a LEB. - * @c: UBIFS file-system description object - * @lnum: LEB number - * @offs: offset - * @sbuf: LEB-sized buffer to use - * @grouped: nodes may be grouped for recovery - * - * This function does a scan of a LEB, but caters for errors that might have - * been caused by the unclean unmount from which we are attempting to recover. - * - * This function returns %0 on success and a negative error code on failure. - */ -struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, - int offs, void *sbuf, int grouped) -{ - int err, len = c->leb_size - offs, need_clean = 0, quiet = 1; - int empty_chkd = 0, start = offs; - struct ubifs_scan_leb *sleb; - void *buf = sbuf + offs; - - dbg_rcvry("%d:%d", lnum, offs); - - sleb = ubifs_start_scan(c, lnum, offs, sbuf); - if (IS_ERR(sleb)) - return sleb; - - if (sleb->ecc) - need_clean = 1; - - while (len >= 8) { - int ret; - - dbg_scan("look at LEB %d:%d (%d bytes left)", - lnum, offs, len); - - cond_resched(); - - /* - * Scan quietly until there is an error from which we cannot - * recover - */ - ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet); - - if (ret == SCANNED_A_NODE) { - /* A valid node, and not a padding node */ - struct ubifs_ch *ch = buf; - int node_len; - - err = ubifs_add_snod(c, sleb, buf, offs); - if (err) - goto error; - node_len = ALIGN(le32_to_cpu(ch->len), 8); - offs += node_len; - buf += node_len; - len -= node_len; - continue; - } - - if (ret > 0) { - /* Padding bytes or a valid padding node */ - offs += ret; - buf += ret; - len -= ret; - continue; - } - - if (ret == SCANNED_EMPTY_SPACE) { - if (!is_empty(buf, len)) { - if (!is_last_write(c, buf, offs)) - break; - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - } - empty_chkd = 1; - break; - } - - if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE) - if (is_last_write(c, buf, offs)) { - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - empty_chkd = 1; - break; - } - - if (ret == SCANNED_A_CORRUPT_NODE) - if (no_more_nodes(c, buf, len, lnum, offs)) { - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - empty_chkd = 1; - break; - } - - if (quiet) { - /* Redo the last scan but noisily */ - quiet = 0; - continue; - } - - switch (ret) { - case SCANNED_GARBAGE: - dbg_err("garbage"); - goto corrupted; - case SCANNED_A_CORRUPT_NODE: - case SCANNED_A_BAD_PAD_NODE: - dbg_err("bad node"); - goto corrupted; - default: - dbg_err("unknown"); - goto corrupted; - } - } - - if (!empty_chkd && !is_empty(buf, len)) { - if (is_last_write(c, buf, offs)) { - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - } else { - ubifs_err("corrupt empty space at LEB %d:%d", - lnum, offs); - goto corrupted; - } - } - - /* Drop nodes from incomplete group */ - if (grouped && drop_incomplete_group(sleb, &offs)) { - buf = sbuf + offs; - len = c->leb_size - offs; - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - } - - if (offs % c->min_io_size) { - clean_buf(c, &buf, lnum, &offs, &len); - need_clean = 1; - } - - ubifs_end_scan(c, sleb, lnum, offs); - - if (need_clean) { - err = fix_unclean_leb(c, sleb, start); - if (err) - goto error; - } - - return sleb; - -corrupted: - ubifs_scanned_corruption(c, lnum, offs, buf); - err = -EUCLEAN; -error: - ubifs_err("LEB %d scanning failed", lnum); - ubifs_scan_destroy(sleb); - return ERR_PTR(err); -} - -/** - * get_cs_sqnum - get commit start sequence number. - * @c: UBIFS file-system description object - * @lnum: LEB number of commit start node - * @offs: offset of commit start node - * @cs_sqnum: commit start sequence number is returned here - * - * This function returns %0 on success and a negative error code on failure. - */ -static int get_cs_sqnum(struct ubifs_info *c, int lnum, int offs, - unsigned long long *cs_sqnum) -{ - struct ubifs_cs_node *cs_node = NULL; - int err, ret; - - dbg_rcvry("at %d:%d", lnum, offs); - cs_node = kmalloc(UBIFS_CS_NODE_SZ, GFP_KERNEL); - if (!cs_node) - return -ENOMEM; - if (c->leb_size - offs < UBIFS_CS_NODE_SZ) - goto out_err; - err = ubi_read(c->ubi, lnum, (void *)cs_node, offs, UBIFS_CS_NODE_SZ); - if (err && err != -EBADMSG) - goto out_free; - ret = ubifs_scan_a_node(c, cs_node, UBIFS_CS_NODE_SZ, lnum, offs, 0); - if (ret != SCANNED_A_NODE) { - dbg_err("Not a valid node"); - goto out_err; - } - if (cs_node->ch.node_type != UBIFS_CS_NODE) { - dbg_err("Node a CS node, type is %d", cs_node->ch.node_type); - goto out_err; - } - if (le64_to_cpu(cs_node->cmt_no) != c->cmt_no) { - dbg_err("CS node cmt_no %llu != current cmt_no %llu", - (unsigned long long)le64_to_cpu(cs_node->cmt_no), - c->cmt_no); - goto out_err; - } - *cs_sqnum = le64_to_cpu(cs_node->ch.sqnum); - dbg_rcvry("commit start sqnum %llu", *cs_sqnum); - kfree(cs_node); - return 0; - -out_err: - err = -EINVAL; -out_free: - ubifs_err("failed to get CS sqnum"); - kfree(cs_node); - return err; -} - -/** - * ubifs_recover_log_leb - scan and recover a log LEB. - * @c: UBIFS file-system description object - * @lnum: LEB number - * @offs: offset - * @sbuf: LEB-sized buffer to use - * - * This function does a scan of a LEB, but caters for errors that might have - * been caused by the unclean unmount from which we are attempting to recover. - * - * This function returns %0 on success and a negative error code on failure. - */ -struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum, - int offs, void *sbuf) -{ - struct ubifs_scan_leb *sleb; - int next_lnum; - - dbg_rcvry("LEB %d", lnum); - next_lnum = lnum + 1; - if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs) - next_lnum = UBIFS_LOG_LNUM; - if (next_lnum != c->ltail_lnum) { - /* - * We can only recover at the end of the log, so check that the - * next log LEB is empty or out of date. - */ - sleb = ubifs_scan(c, next_lnum, 0, sbuf); - if (IS_ERR(sleb)) - return sleb; - if (sleb->nodes_cnt) { - struct ubifs_scan_node *snod; - unsigned long long cs_sqnum = c->cs_sqnum; - - snod = list_entry(sleb->nodes.next, - struct ubifs_scan_node, list); - if (cs_sqnum == 0) { - int err; - - err = get_cs_sqnum(c, lnum, offs, &cs_sqnum); - if (err) { - ubifs_scan_destroy(sleb); - return ERR_PTR(err); - } - } - if (snod->sqnum > cs_sqnum) { - ubifs_err("unrecoverable log corruption " - "in LEB %d", lnum); - ubifs_scan_destroy(sleb); - return ERR_PTR(-EUCLEAN); - } - } - ubifs_scan_destroy(sleb); - } - return ubifs_recover_leb(c, lnum, offs, sbuf, 0); -} - -/** - * recover_head - recover a head. - * @c: UBIFS file-system description object - * @lnum: LEB number of head to recover - * @offs: offset of head to recover - * @sbuf: LEB-sized buffer to use - * - * This function ensures that there is no data on the flash at a head location. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int recover_head(const struct ubifs_info *c, int lnum, int offs, - void *sbuf) -{ - int len, err, need_clean = 0; - - if (c->min_io_size > 1) - len = c->min_io_size; - else - len = 512; - if (offs + len > c->leb_size) - len = c->leb_size - offs; - - if (!len) - return 0; - - /* Read at the head location and check it is empty flash */ - err = ubi_read(c->ubi, lnum, sbuf, offs, len); - if (err) - need_clean = 1; - else { - uint8_t *p = sbuf; - - while (len--) - if (*p++ != 0xff) { - need_clean = 1; - break; - } - } - - if (need_clean) { - dbg_rcvry("cleaning head at %d:%d", lnum, offs); - if (offs == 0) - return ubifs_leb_unmap(c, lnum); - err = ubi_read(c->ubi, lnum, sbuf, 0, offs); - if (err) - return err; - return ubi_leb_change(c->ubi, lnum, sbuf, offs, UBI_UNKNOWN); - } - - return 0; -} - -/** - * ubifs_recover_inl_heads - recover index and LPT heads. - * @c: UBIFS file-system description object - * @sbuf: LEB-sized buffer to use - * - * This function ensures that there is no data on the flash at the index and - * LPT head locations. - * - * This deals with the recovery of a half-completed journal commit. UBIFS is - * careful never to overwrite the last version of the index or the LPT. Because - * the index and LPT are wandering trees, data from a half-completed commit will - * not be referenced anywhere in UBIFS. The data will be either in LEBs that are - * assumed to be empty and will be unmapped anyway before use, or in the index - * and LPT heads. - * - * This function returns %0 on success and a negative error code on failure. - */ -int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf) -{ - int err; - - ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY) || c->remounting_rw); - - dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs); - err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf); - if (err) - return err; - - dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs); - err = recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf); - if (err) - return err; - - return 0; -} - -/** - * clean_an_unclean_leb - read and write a LEB to remove corruption. - * @c: UBIFS file-system description object - * @ucleb: unclean LEB information - * @sbuf: LEB-sized buffer to use - * - * This function reads a LEB up to a point pre-determined by the mount recovery, - * checks the nodes, and writes the result back to the flash, thereby cleaning - * off any following corruption, or non-fatal ECC errors. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int clean_an_unclean_leb(const struct ubifs_info *c, - struct ubifs_unclean_leb *ucleb, void *sbuf) -{ - int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1; - void *buf = sbuf; - - dbg_rcvry("LEB %d len %d", lnum, len); - - if (len == 0) { - /* Nothing to read, just unmap it */ - err = ubifs_leb_unmap(c, lnum); - if (err) - return err; - return 0; - } - - err = ubi_read(c->ubi, lnum, buf, offs, len); - if (err && err != -EBADMSG) - return err; - - while (len >= 8) { - int ret; - - cond_resched(); - - /* Scan quietly until there is an error */ - ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet); - - if (ret == SCANNED_A_NODE) { - /* A valid node, and not a padding node */ - struct ubifs_ch *ch = buf; - int node_len; - - node_len = ALIGN(le32_to_cpu(ch->len), 8); - offs += node_len; - buf += node_len; - len -= node_len; - continue; - } - - if (ret > 0) { - /* Padding bytes or a valid padding node */ - offs += ret; - buf += ret; - len -= ret; - continue; - } - - if (ret == SCANNED_EMPTY_SPACE) { - ubifs_err("unexpected empty space at %d:%d", - lnum, offs); - return -EUCLEAN; - } - - if (quiet) { - /* Redo the last scan but noisily */ - quiet = 0; - continue; - } - - ubifs_scanned_corruption(c, lnum, offs, buf); - return -EUCLEAN; - } - - /* Pad to min_io_size */ - len = ALIGN(ucleb->endpt, c->min_io_size); - if (len > ucleb->endpt) { - int pad_len = len - ALIGN(ucleb->endpt, 8); - - if (pad_len > 0) { - buf = c->sbuf + len - pad_len; - ubifs_pad(c, buf, pad_len); - } - } - - /* Write back the LEB atomically */ - err = ubi_leb_change(c->ubi, lnum, sbuf, len, UBI_UNKNOWN); - if (err) - return err; - - dbg_rcvry("cleaned LEB %d", lnum); - - return 0; -} - -/** - * ubifs_clean_lebs - clean LEBs recovered during read-only mount. - * @c: UBIFS file-system description object - * @sbuf: LEB-sized buffer to use - * - * This function cleans a LEB identified during recovery that needs to be - * written but was not because UBIFS was mounted read-only. This happens when - * remounting to read-write mode. - * - * This function returns %0 on success and a negative error code on failure. - */ -int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf) -{ - dbg_rcvry("recovery"); - while (!list_empty(&c->unclean_leb_list)) { - struct ubifs_unclean_leb *ucleb; - int err; - - ucleb = list_entry(c->unclean_leb_list.next, - struct ubifs_unclean_leb, list); - err = clean_an_unclean_leb(c, ucleb, sbuf); - if (err) - return err; - list_del(&ucleb->list); - kfree(ucleb); - } - return 0; -} - -/** - * struct size_entry - inode size information for recovery. - * @rb: link in the RB-tree of sizes - * @inum: inode number - * @i_size: size on inode - * @d_size: maximum size based on data nodes - * @exists: indicates whether the inode exists - * @inode: inode if pinned in memory awaiting rw mode to fix it - */ -struct size_entry { - struct rb_node rb; - ino_t inum; - loff_t i_size; - loff_t d_size; - int exists; - struct inode *inode; -}; - -/** - * add_ino - add an entry to the size tree. - * @c: UBIFS file-system description object - * @inum: inode number - * @i_size: size on inode - * @d_size: maximum size based on data nodes - * @exists: indicates whether the inode exists - */ -static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size, - loff_t d_size, int exists) -{ - struct rb_node **p = &c->size_tree.rb_node, *parent = NULL; - struct size_entry *e; - - while (*p) { - parent = *p; - e = rb_entry(parent, struct size_entry, rb); - if (inum < e->inum) - p = &(*p)->rb_left; - else - p = &(*p)->rb_right; - } - - e = kzalloc(sizeof(struct size_entry), GFP_KERNEL); - if (!e) - return -ENOMEM; - - e->inum = inum; - e->i_size = i_size; - e->d_size = d_size; - e->exists = exists; - - rb_link_node(&e->rb, parent, p); - rb_insert_color(&e->rb, &c->size_tree); - - return 0; -} - -/** - * find_ino - find an entry on the size tree. - * @c: UBIFS file-system description object - * @inum: inode number - */ -static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum) -{ - struct rb_node *p = c->size_tree.rb_node; - struct size_entry *e; - - while (p) { - e = rb_entry(p, struct size_entry, rb); - if (inum < e->inum) - p = p->rb_left; - else if (inum > e->inum) - p = p->rb_right; - else - return e; - } - return NULL; -} - -/** - * remove_ino - remove an entry from the size tree. - * @c: UBIFS file-system description object - * @inum: inode number - */ -static void remove_ino(struct ubifs_info *c, ino_t inum) -{ - struct size_entry *e = find_ino(c, inum); - - if (!e) - return; - rb_erase(&e->rb, &c->size_tree); - kfree(e); -} - -/** - * ubifs_recover_size_accum - accumulate inode sizes for recovery. - * @c: UBIFS file-system description object - * @key: node key - * @deletion: node is for a deletion - * @new_size: inode size - * - * This function has two purposes: - * 1) to ensure there are no data nodes that fall outside the inode size - * 2) to ensure there are no data nodes for inodes that do not exist - * To accomplish those purposes, a rb-tree is constructed containing an entry - * for each inode number in the journal that has not been deleted, and recording - * the size from the inode node, the maximum size of any data node (also altered - * by truncations) and a flag indicating a inode number for which no inode node - * was present in the journal. - * - * Note that there is still the possibility that there are data nodes that have - * been committed that are beyond the inode size, however the only way to find - * them would be to scan the entire index. Alternatively, some provision could - * be made to record the size of inodes at the start of commit, which would seem - * very cumbersome for a scenario that is quite unlikely and the only negative - * consequence of which is wasted space. - * - * This functions returns %0 on success and a negative error code on failure. - */ -int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key, - int deletion, loff_t new_size) -{ - ino_t inum = key_inum(c, key); - struct size_entry *e; - int err; - - switch (key_type(c, key)) { - case UBIFS_INO_KEY: - if (deletion) - remove_ino(c, inum); - else { - e = find_ino(c, inum); - if (e) { - e->i_size = new_size; - e->exists = 1; - } else { - err = add_ino(c, inum, new_size, 0, 1); - if (err) - return err; - } - } - break; - case UBIFS_DATA_KEY: - e = find_ino(c, inum); - if (e) { - if (new_size > e->d_size) - e->d_size = new_size; - } else { - err = add_ino(c, inum, 0, new_size, 0); - if (err) - return err; - } - break; - case UBIFS_TRUN_KEY: - e = find_ino(c, inum); - if (e) - e->d_size = new_size; - break; - } - return 0; -} - -/** - * ubifs_recover_size - recover inode size. - * @c: UBIFS file-system description object - * - * This function attempts to fix inode size discrepancies identified by the - * 'ubifs_recover_size_accum()' function. - * - * This functions returns %0 on success and a negative error code on failure. - */ -int ubifs_recover_size(struct ubifs_info *c) -{ - struct rb_node *this = rb_first(&c->size_tree); - - while (this) { - struct size_entry *e; - int err; - - e = rb_entry(this, struct size_entry, rb); - if (!e->exists) { - union ubifs_key key; - - ino_key_init(c, &key, e->inum); - err = ubifs_tnc_lookup(c, &key, c->sbuf); - if (err && err != -ENOENT) - return err; - if (err == -ENOENT) { - /* Remove data nodes that have no inode */ - dbg_rcvry("removing ino %lu", - (unsigned long)e->inum); - err = ubifs_tnc_remove_ino(c, e->inum); - if (err) - return err; - } else { - struct ubifs_ino_node *ino = c->sbuf; - - e->exists = 1; - e->i_size = le64_to_cpu(ino->size); - } - } - if (e->exists && e->i_size < e->d_size) { - if (!e->inode && (c->vfs_sb->s_flags & MS_RDONLY)) { - /* Fix the inode size and pin it in memory */ - struct inode *inode; - - inode = ubifs_iget(c->vfs_sb, e->inum); - if (IS_ERR(inode)) - return PTR_ERR(inode); - if (inode->i_size < e->d_size) { - dbg_rcvry("ino %lu size %lld -> %lld", - (unsigned long)e->inum, - e->d_size, inode->i_size); - inode->i_size = e->d_size; - ubifs_inode(inode)->ui_size = e->d_size; - e->inode = inode; - this = rb_next(this); - continue; - } - iput(inode); - } - } - this = rb_next(this); - rb_erase(&e->rb, &c->size_tree); - kfree(e); - } - return 0; -} |