UBIFS: add new flash file system

This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.html

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>

1 files changed, 1519 insertions, 0 deletions

diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c
new file mode 100644
index 000000000000..77d26c141cf6
--- /dev/null
+++ b/fs/ubifs/recovery.c
@@ -0,0 +1,1519 @@
+/*
+ * 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 <linux/crc32.h>
+#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;
+        uint32_t save_flags;
+
+        dbg_rcvry("recovery");
+
+        save_flags = mst->flags;
+        mst->flags = cpu_to_le32(le32_to_cpu(mst->flags) | 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);
+        } else {
+                /* Write the recovered master node */
+                c->max_sqnum = le64_to_cpu(mst->ch.sqnum) - 1;
+                err = write_rcvrd_mst_node(c, c->mst_node);
+                if (err)
+                        goto out_free;
+        }
+
+        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 scans @buf for more nodes and returns %0 is a node is found and
+ * %1 if no more nodes are found.
+ */
+static int no_more_nodes(const struct ubifs_info *c, void *buf, int len,
+                        int lnum, int offs)
+{
+        int skip, next_offs = 0;
+
+        if (len > UBIFS_DATA_NODE_SZ) {
+                struct ubifs_ch *ch = buf;
+                int dlen = le32_to_cpu(ch->len);
+
+                if (ch->node_type == UBIFS_DATA_NODE && dlen >= UBIFS_CH_SZ &&
+                    dlen <= UBIFS_MAX_DATA_NODE_SZ)
+                        /* The corrupt node looks like a data node */
+                        next_offs = ALIGN(offs + dlen, 8);
+        }
+
+        if (c->min_io_size == 1)
+                skip = 8;
+        else
+                skip = ALIGN(offs + 1, c->min_io_size) - offs;
+
+        offs += skip;
+        buf += skip;
+        len -= skip;
+        while (len > 8) {
+                struct ubifs_ch *ch = buf;
+                uint32_t magic = le32_to_cpu(ch->magic);
+                int ret;
+
+                if (magic == UBIFS_NODE_MAGIC) {
+                        ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
+                        if (ret == SCANNED_A_NODE || ret > 0) {
+                                /*
+                                 * There is a small chance this is just data in
+                                 * a data node, so check that possibility. e.g.
+                                 * this is part of a file that itself contains
+                                 * a UBIFS image.
+                                 */
+                                if (next_offs && offs + le32_to_cpu(ch->len) <=
+                                    next_offs)
+                                        continue;
+                                dbg_rcvry("unexpected node at %d:%d", lnum,
+                                          offs);
+                                return 0;
+                        }
+                }
+                offs += 8;
+                buf += 8;
+                len -= 8;
+        }
+        return 1;
+}
+
+/**
+ * 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);
+        } else {
+                /* Write the fixed LEB back to flash */
+                int err;
+
+                dbg_rcvry("fixing LEB %d start %d endpt %d",
+                          lnum, start, sleb->endpt);
+                if (endpt == 0) {
+                        err = ubifs_leb_unmap(c, lnum);
+                        if (err)
+                                return err;
+                } else {
+                        int len = ALIGN(endpt, c->min_io_size);
+
+                        if (start) {
+                                err = ubi_read(c->ubi, lnum, sleb->buf, 0,
+                                               start);
+                                if (err)
+                                        return err;
+                        }
+                        /* Pad to min_io_size */
+                        if (len > endpt) {
+                                int pad_len = len - ALIGN(endpt, 8);
+
+                                if (pad_len > 0) {
+                                        void *buf = sleb->buf + len - pad_len;
+
+                                        ubifs_pad(c, buf, pad_len);
+                                }
+                        }
+                        err = ubi_leb_change(c->ubi, lnum, sleb->buf, len,
+                                             UBI_UNKNOWN);
+                        if (err)
+                                return err;
+                }
+        }
+        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;
+}
+
+/**
+ * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
+ * @c: UBIFS file-system description object
+ *
+ * Out-of-place garbage collection requires always one empty LEB with which to
+ * start garbage collection. The LEB number is recorded in c->gc_lnum and is
+ * written to the master node on unmounting. In the case of an unclean unmount
+ * the value of gc_lnum recorded in the master node is out of date and cannot
+ * be used. Instead, recovery must allocate an empty LEB for this purpose.
+ * However, there may not be enough empty space, in which case it must be
+ * possible to GC the dirtiest LEB into the GC head LEB.
+ *
+ * This function also runs the commit which causes the TNC updates from
+ * size-recovery and orphans to be written to the flash. That is important to
+ * ensure correct replay order for subsequent mounts.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_rcvry_gc_commit(struct ubifs_info *c)
+{
+        struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
+        struct ubifs_lprops lp;
+        int lnum, err;
+
+        c->gc_lnum = -1;
+        if (wbuf->lnum == -1) {
+                dbg_rcvry("no GC head LEB");
+                goto find_free;
+        }
+        /*
+         * See whether the used space in the dirtiest LEB fits in the GC head
+         * LEB.
+         */
+        if (wbuf->offs == c->leb_size) {
+                dbg_rcvry("no room in GC head LEB");
+                goto find_free;
+        }
+        err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
+        if (err) {
+                if (err == -ENOSPC)
+                        dbg_err("could not find a dirty LEB");
+                return err;
+        }
+        ubifs_assert(!(lp.flags & LPROPS_INDEX));
+        lnum = lp.lnum;
+        if (lp.free + lp.dirty == c->leb_size) {
+                /* An empty LEB was returned */
+                if (lp.free != c->leb_size) {
+                        err = ubifs_change_one_lp(c, lnum, c->leb_size,
+                                                  0, 0, 0, 0);
+                        if (err)
+                                return err;
+                }
+                err = ubifs_leb_unmap(c, lnum);
+                if (err)
+                        return err;
+                c->gc_lnum = lnum;
+                dbg_rcvry("allocated LEB %d for GC", lnum);
+                /* Run the commit */
+                dbg_rcvry("committing");
+                return ubifs_run_commit(c);
+        }
+        /*
+         * There was no empty LEB so the used space in the dirtiest LEB must fit
+         * in the GC head LEB.
+         */
+        if (lp.free + lp.dirty < wbuf->offs) {
+                dbg_rcvry("LEB %d doesn't fit in GC head LEB %d:%d",
+                          lnum, wbuf->lnum, wbuf->offs);
+                err = ubifs_return_leb(c, lnum);
+                if (err)
+                        return err;
+                goto find_free;
+        }
+        /*
+         * We run the commit before garbage collection otherwise subsequent
+         * mounts will see the GC and orphan deletion in a different order.
+         */
+        dbg_rcvry("committing");
+        err = ubifs_run_commit(c);
+        if (err)
+                return err;
+        /*
+         * The data in the dirtiest LEB fits in the GC head LEB, so do the GC
+         * - use locking to keep 'ubifs_assert()' happy.
+         */
+        dbg_rcvry("GC'ing LEB %d", lnum);
+        mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
+        err = ubifs_garbage_collect_leb(c, &lp);
+        if (err >= 0) {
+                int err2 = ubifs_wbuf_sync_nolock(wbuf);
+
+                if (err2)
+                        err = err2;
+        }
+        mutex_unlock(&wbuf->io_mutex);
+        if (err < 0) {
+                dbg_err("GC failed, error %d", err);
+                if (err == -EAGAIN)
+                        err = -EINVAL;
+                return err;
+        }
+        if (err != LEB_RETAINED) {
+                dbg_err("GC returned %d", err);
+                return -EINVAL;
+        }
+        err = ubifs_leb_unmap(c, c->gc_lnum);
+        if (err)
+                return err;
+        dbg_rcvry("allocated LEB %d for GC", lnum);
+        return 0;
+
+find_free:
+        /*
+         * There is no GC head LEB or the free space in the GC head LEB is too
+         * small. Allocate gc_lnum by calling 'ubifs_find_free_leb_for_idx()' so
+         * GC is not run.
+         */
+        lnum = ubifs_find_free_leb_for_idx(c);
+        if (lnum < 0) {
+                dbg_err("could not find an empty LEB");
+                return lnum;
+        }
+        /* And reset the index flag */
+        err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
+                                  LPROPS_INDEX, 0);
+        if (err)
+                return err;
+        c->gc_lnum = lnum;
+        dbg_rcvry("allocated LEB %d for GC", lnum);
+        /* Run the commit */
+        dbg_rcvry("committing");
+        return ubifs_run_commit(c);
+}
+
+/**
+ * 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_destroy_size_tree - free resources related to the size tree.
+ * @c: UBIFS file-system description object
+ */
+void ubifs_destroy_size_tree(struct ubifs_info *c)
+{
+        struct rb_node *this = c->size_tree.rb_node;
+        struct size_entry *e;
+
+        while (this) {
+                if (this->rb_left) {
+                        this = this->rb_left;
+                        continue;
+                } else if (this->rb_right) {
+                        this = this->rb_right;
+                        continue;
+                }
+                e = rb_entry(this, struct size_entry, rb);
+                if (e->inode)
+                        iput(e->inode);
+                this = rb_parent(this);
+                if (this) {
+                        if (this->rb_left == &e->rb)
+                                this->rb_left = NULL;
+                        else
+                                this->rb_right = NULL;
+                }
+                kfree(e);
+        }
+        c->size_tree = RB_ROOT;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * fix_size_in_place - fix inode size in place on flash.
+ * @c: UBIFS file-system description object
+ * @e: inode size information for recovery
+ */
+static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e)
+{
+        struct ubifs_ino_node *ino = c->sbuf;
+        unsigned char *p;
+        union ubifs_key key;
+        int err, lnum, offs, len;
+        loff_t i_size;
+        uint32_t crc;
+
+        /* Locate the inode node LEB number and offset */
+        ino_key_init(c, &key, e->inum);
+        err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs);
+        if (err)
+                goto out;
+        /*
+         * If the size recorded on the inode node is greater than the size that
+         * was calculated from nodes in the journal then don't change the inode.
+         */
+        i_size = le64_to_cpu(ino->size);
+        if (i_size >= e->d_size)
+                return 0;
+        /* Read the LEB */
+        err = ubi_read(c->ubi, lnum, c->sbuf, 0, c->leb_size);
+        if (err)
+                goto out;
+        /* Change the size field and recalculate the CRC */
+        ino = c->sbuf + offs;
+        ino->size = cpu_to_le64(e->d_size);
+        len = le32_to_cpu(ino->ch.len);
+        crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8);
+        ino->ch.crc = cpu_to_le32(crc);
+        /* Work out where data in the LEB ends and free space begins */
+        p = c->sbuf;
+        len = c->leb_size - 1;
+        while (p[len] == 0xff)
+                len -= 1;
+        len = ALIGN(len + 1, c->min_io_size);
+        /* Atomically write the fixed LEB back again */
+        err = ubi_leb_change(c->ubi, lnum, c->sbuf, len, UBI_UNKNOWN);
+        if (err)
+                goto out;
+        dbg_rcvry("inode %lu at %d:%d size %lld -> %lld ", e->inum, lnum, offs,
+                  i_size, e->d_size);
+        return 0;
+
+out:
+        ubifs_warn("inode %lu failed to fix size %lld -> %lld error %d",
+                   e->inum, e->i_size, e->d_size, err);
+        return err;
+}
+
+/**
+ * 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", 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",
+                                                  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);
+                        } else {
+                                /* Fix the size in place */
+                                err = fix_size_in_place(c, e);
+                                if (err)
+                                        return err;
+                                if (e->inode)
+                                        iput(e->inode);
+                        }
+                }
+                this = rb_next(this);
+                rb_erase(&e->rb, &c->size_tree);
+                kfree(e);
+        }
+        return 0;
+}