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![Adrian Hunter](/assets/img/avatar_default.png)
UBIFS did not recovery in a situation in which it could have. The relevant function assumed there could not be more nodes in an eraseblock after a corrupted node, but in fact the last (NAND) page written might contain anything. The correct approach is to check for empty space (0xFF bytes) from then on. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> Signed-off-by: Stefan Roese <sr@denx.de>
1226 lines
31 KiB
C
1226 lines
31 KiB
C
/*
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* This file is part of UBIFS.
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*
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* Copyright (C) 2006-2008 Nokia Corporation
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Authors: Adrian Hunter
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* Artem Bityutskiy (Битюцкий Артём)
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*/
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/*
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* This file implements functions needed to recover from unclean un-mounts.
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* When UBIFS is mounted, it checks a flag on the master node to determine if
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* an un-mount was completed sucessfully. If not, the process of mounting
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* incorparates additional checking and fixing of on-flash data structures.
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* UBIFS always cleans away all remnants of an unclean un-mount, so that
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* errors do not accumulate. However UBIFS defers recovery if it is mounted
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* read-only, and the flash is not modified in that case.
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*/
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#include "ubifs.h"
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/**
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* is_empty - determine whether a buffer is empty (contains all 0xff).
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* @buf: buffer to clean
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* @len: length of buffer
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*
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* This function returns %1 if the buffer is empty (contains all 0xff) otherwise
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* %0 is returned.
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*/
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static int is_empty(void *buf, int len)
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{
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uint8_t *p = buf;
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int i;
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for (i = 0; i < len; i++)
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if (*p++ != 0xff)
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return 0;
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return 1;
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}
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/**
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* get_master_node - get the last valid master node allowing for corruption.
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* @c: UBIFS file-system description object
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* @lnum: LEB number
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* @pbuf: buffer containing the LEB read, is returned here
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* @mst: master node, if found, is returned here
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* @cor: corruption, if found, is returned here
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*
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* This function allocates a buffer, reads the LEB into it, and finds and
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* returns the last valid master node allowing for one area of corruption.
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* The corrupt area, if there is one, must be consistent with the assumption
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* that it is the result of an unclean unmount while the master node was being
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* written. Under those circumstances, it is valid to use the previously written
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* master node.
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf,
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struct ubifs_mst_node **mst, void **cor)
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{
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const int sz = c->mst_node_alsz;
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int err, offs, len;
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void *sbuf, *buf;
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sbuf = vmalloc(c->leb_size);
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if (!sbuf)
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return -ENOMEM;
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err = ubi_read(c->ubi, lnum, sbuf, 0, c->leb_size);
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if (err && err != -EBADMSG)
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goto out_free;
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/* Find the first position that is definitely not a node */
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offs = 0;
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buf = sbuf;
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len = c->leb_size;
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while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) {
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struct ubifs_ch *ch = buf;
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if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
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break;
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offs += sz;
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buf += sz;
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len -= sz;
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}
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/* See if there was a valid master node before that */
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if (offs) {
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int ret;
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offs -= sz;
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buf -= sz;
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len += sz;
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ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
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if (ret != SCANNED_A_NODE && offs) {
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/* Could have been corruption so check one place back */
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offs -= sz;
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buf -= sz;
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len += sz;
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ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
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if (ret != SCANNED_A_NODE)
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/*
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* We accept only one area of corruption because
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* we are assuming that it was caused while
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* trying to write a master node.
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*/
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goto out_err;
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}
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if (ret == SCANNED_A_NODE) {
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struct ubifs_ch *ch = buf;
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if (ch->node_type != UBIFS_MST_NODE)
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goto out_err;
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dbg_rcvry("found a master node at %d:%d", lnum, offs);
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*mst = buf;
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offs += sz;
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buf += sz;
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len -= sz;
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}
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}
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/* Check for corruption */
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if (offs < c->leb_size) {
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if (!is_empty(buf, min_t(int, len, sz))) {
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*cor = buf;
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dbg_rcvry("found corruption at %d:%d", lnum, offs);
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}
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offs += sz;
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buf += sz;
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len -= sz;
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}
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/* Check remaining empty space */
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if (offs < c->leb_size)
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if (!is_empty(buf, len))
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goto out_err;
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*pbuf = sbuf;
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return 0;
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out_err:
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err = -EINVAL;
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out_free:
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vfree(sbuf);
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*mst = NULL;
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*cor = NULL;
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return err;
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}
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/**
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* write_rcvrd_mst_node - write recovered master node.
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* @c: UBIFS file-system description object
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* @mst: master node
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static int write_rcvrd_mst_node(struct ubifs_info *c,
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struct ubifs_mst_node *mst)
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{
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int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz;
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__le32 save_flags;
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dbg_rcvry("recovery");
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save_flags = mst->flags;
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mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY);
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ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1);
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err = ubi_leb_change(c->ubi, lnum, mst, sz, UBI_SHORTTERM);
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if (err)
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goto out;
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err = ubi_leb_change(c->ubi, lnum + 1, mst, sz, UBI_SHORTTERM);
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if (err)
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goto out;
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out:
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mst->flags = save_flags;
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return err;
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}
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/**
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* ubifs_recover_master_node - recover the master node.
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* @c: UBIFS file-system description object
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*
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* This function recovers the master node from corruption that may occur due to
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* an unclean unmount.
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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int ubifs_recover_master_node(struct ubifs_info *c)
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{
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void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL;
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struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst;
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const int sz = c->mst_node_alsz;
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int err, offs1, offs2;
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dbg_rcvry("recovery");
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err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1);
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if (err)
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goto out_free;
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err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2);
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if (err)
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goto out_free;
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if (mst1) {
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offs1 = (void *)mst1 - buf1;
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if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) &&
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(offs1 == 0 && !cor1)) {
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/*
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* mst1 was written by recovery at offset 0 with no
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* corruption.
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*/
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dbg_rcvry("recovery recovery");
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mst = mst1;
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} else if (mst2) {
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offs2 = (void *)mst2 - buf2;
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if (offs1 == offs2) {
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/* Same offset, so must be the same */
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if (memcmp((void *)mst1 + UBIFS_CH_SZ,
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(void *)mst2 + UBIFS_CH_SZ,
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UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
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goto out_err;
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mst = mst1;
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} else if (offs2 + sz == offs1) {
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/* 1st LEB was written, 2nd was not */
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if (cor1)
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goto out_err;
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mst = mst1;
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} else if (offs1 == 0 && offs2 + sz >= c->leb_size) {
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/* 1st LEB was unmapped and written, 2nd not */
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if (cor1)
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goto out_err;
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mst = mst1;
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} else
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goto out_err;
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} else {
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/*
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* 2nd LEB was unmapped and about to be written, so
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* there must be only one master node in the first LEB
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* and no corruption.
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*/
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if (offs1 != 0 || cor1)
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goto out_err;
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mst = mst1;
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}
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} else {
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if (!mst2)
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goto out_err;
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/*
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* 1st LEB was unmapped and about to be written, so there must
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* be no room left in 2nd LEB.
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*/
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offs2 = (void *)mst2 - buf2;
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if (offs2 + sz + sz <= c->leb_size)
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goto out_err;
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mst = mst2;
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}
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dbg_rcvry("recovered master node from LEB %d",
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(mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1));
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memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ);
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if ((c->vfs_sb->s_flags & MS_RDONLY)) {
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/* Read-only mode. Keep a copy for switching to rw mode */
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c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL);
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if (!c->rcvrd_mst_node) {
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err = -ENOMEM;
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goto out_free;
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}
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memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ);
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}
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vfree(buf2);
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vfree(buf1);
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return 0;
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out_err:
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err = -EINVAL;
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out_free:
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ubifs_err("failed to recover master node");
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if (mst1) {
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dbg_err("dumping first master node");
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dbg_dump_node(c, mst1);
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}
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if (mst2) {
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dbg_err("dumping second master node");
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dbg_dump_node(c, mst2);
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}
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vfree(buf2);
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vfree(buf1);
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return err;
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}
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/**
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* ubifs_write_rcvrd_mst_node - write the recovered master node.
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* @c: UBIFS file-system description object
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*
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* This function writes the master node that was recovered during mounting in
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* read-only mode and must now be written because we are remounting rw.
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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int ubifs_write_rcvrd_mst_node(struct ubifs_info *c)
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{
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int err;
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if (!c->rcvrd_mst_node)
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return 0;
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c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
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c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
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err = write_rcvrd_mst_node(c, c->rcvrd_mst_node);
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if (err)
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return err;
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kfree(c->rcvrd_mst_node);
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c->rcvrd_mst_node = NULL;
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return 0;
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}
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/**
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* is_last_write - determine if an offset was in the last write to a LEB.
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* @c: UBIFS file-system description object
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* @buf: buffer to check
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* @offs: offset to check
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*
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* This function returns %1 if @offs was in the last write to the LEB whose data
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* is in @buf, otherwise %0 is returned. The determination is made by checking
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* for subsequent empty space starting from the next min_io_size boundary (or a
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* bit less than the common header size if min_io_size is one).
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*/
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static int is_last_write(const struct ubifs_info *c, void *buf, int offs)
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{
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int empty_offs;
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int check_len;
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uint8_t *p;
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if (c->min_io_size == 1) {
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check_len = c->leb_size - offs;
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p = buf + check_len;
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for (; check_len > 0; check_len--)
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if (*--p != 0xff)
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break;
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/*
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* 'check_len' is the size of the corruption which cannot be
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* more than the size of 1 node if it was caused by an unclean
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* unmount.
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*/
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if (check_len > UBIFS_MAX_NODE_SZ)
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return 0;
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return 1;
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}
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/*
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* Round up to the next c->min_io_size boundary i.e. 'offs' is in the
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* last wbuf written. After that should be empty space.
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*/
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empty_offs = ALIGN(offs + 1, c->min_io_size);
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check_len = c->leb_size - empty_offs;
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p = buf + empty_offs - offs;
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for (; check_len > 0; check_len--)
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if (*p++ != 0xff)
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return 0;
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return 1;
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}
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/**
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* clean_buf - clean the data from an LEB sitting in a buffer.
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* @c: UBIFS file-system description object
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* @buf: buffer to clean
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* @lnum: LEB number to clean
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* @offs: offset from which to clean
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* @len: length of buffer
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*
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* This function pads up to the next min_io_size boundary (if there is one) and
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* sets empty space to all 0xff. @buf, @offs and @len are updated to the next
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* min_io_size boundary (if there is one).
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*/
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static void clean_buf(const struct ubifs_info *c, void **buf, int lnum,
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int *offs, int *len)
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{
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int empty_offs, pad_len;
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lnum = lnum;
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dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs);
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if (c->min_io_size == 1) {
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memset(*buf, 0xff, c->leb_size - *offs);
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return;
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}
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|
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ubifs_assert(!(*offs & 7));
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empty_offs = ALIGN(*offs, c->min_io_size);
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pad_len = empty_offs - *offs;
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ubifs_pad(c, *buf, pad_len);
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*offs += pad_len;
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*buf += pad_len;
|
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*len -= pad_len;
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memset(*buf, 0xff, c->leb_size - empty_offs);
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}
|
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|
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/**
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* no_more_nodes - determine if there are no more nodes in a buffer.
|
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* @c: UBIFS file-system description object
|
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* @buf: buffer to check
|
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* @len: length of buffer
|
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* @lnum: LEB number of the LEB from which @buf was read
|
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* @offs: offset from which @buf was read
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*
|
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* This function ensures that the corrupted node at @offs is the last thing
|
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* written to a LEB. This function returns %1 if more data is not found and
|
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* %0 if more data is found.
|
|
*/
|
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static int no_more_nodes(const struct ubifs_info *c, void *buf, int len,
|
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int lnum, int offs)
|
|
{
|
|
struct ubifs_ch *ch = buf;
|
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int skip, dlen = le32_to_cpu(ch->len);
|
|
|
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/* Check for empty space after the corrupt node's common header */
|
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skip = ALIGN(offs + UBIFS_CH_SZ, c->min_io_size) - offs;
|
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if (is_empty(buf + skip, len - skip))
|
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return 1;
|
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/*
|
|
* 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) {
|
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dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs);
|
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return 0;
|
|
}
|
|
/* Now we know the corrupt node's length we can skip over it */
|
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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;
|
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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;
|
|
}
|