summaryrefslogtreecommitdiffstats
path: root/fs/ubifs/orphan.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/ubifs/orphan.c')
-rw-r--r--fs/ubifs/orphan.c1050
1 files changed, 1050 insertions, 0 deletions
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
new file mode 100644
index 000000000..0fb619561
--- /dev/null
+++ b/fs/ubifs/orphan.c
@@ -0,0 +1,1050 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Author: Adrian Hunter
+ */
+
+#include "ubifs.h"
+
+/*
+ * An orphan is an inode number whose inode node has been committed to the index
+ * with a link count of zero. That happens when an open file is deleted
+ * (unlinked) and then a commit is run. In the normal course of events the inode
+ * would be deleted when the file is closed. However in the case of an unclean
+ * unmount, orphans need to be accounted for. After an unclean unmount, the
+ * orphans' inodes must be deleted which means either scanning the entire index
+ * looking for them, or keeping a list on flash somewhere. This unit implements
+ * the latter approach.
+ *
+ * The orphan area is a fixed number of LEBs situated between the LPT area and
+ * the main area. The number of orphan area LEBs is specified when the file
+ * system is created. The minimum number is 1. The size of the orphan area
+ * should be so that it can hold the maximum number of orphans that are expected
+ * to ever exist at one time.
+ *
+ * The number of orphans that can fit in a LEB is:
+ *
+ * (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
+ *
+ * For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
+ *
+ * Orphans are accumulated in a rb-tree. When an inode's link count drops to
+ * zero, the inode number is added to the rb-tree. It is removed from the tree
+ * when the inode is deleted. Any new orphans that are in the orphan tree when
+ * the commit is run, are written to the orphan area in 1 or more orphan nodes.
+ * If the orphan area is full, it is consolidated to make space. There is
+ * always enough space because validation prevents the user from creating more
+ * than the maximum number of orphans allowed.
+ */
+
+static int dbg_check_orphans(struct ubifs_info *c);
+
+static struct ubifs_orphan *orphan_add(struct ubifs_info *c, ino_t inum,
+ struct ubifs_orphan *parent_orphan)
+{
+ struct ubifs_orphan *orphan, *o;
+ struct rb_node **p, *parent = NULL;
+
+ orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS);
+ if (!orphan)
+ return ERR_PTR(-ENOMEM);
+ orphan->inum = inum;
+ orphan->new = 1;
+ INIT_LIST_HEAD(&orphan->child_list);
+
+ spin_lock(&c->orphan_lock);
+ if (c->tot_orphans >= c->max_orphans) {
+ spin_unlock(&c->orphan_lock);
+ kfree(orphan);
+ return ERR_PTR(-ENFILE);
+ }
+ p = &c->orph_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ o = rb_entry(parent, struct ubifs_orphan, rb);
+ if (inum < o->inum)
+ p = &(*p)->rb_left;
+ else if (inum > o->inum)
+ p = &(*p)->rb_right;
+ else {
+ ubifs_err(c, "orphaned twice");
+ spin_unlock(&c->orphan_lock);
+ kfree(orphan);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+ c->tot_orphans += 1;
+ c->new_orphans += 1;
+ rb_link_node(&orphan->rb, parent, p);
+ rb_insert_color(&orphan->rb, &c->orph_tree);
+ list_add_tail(&orphan->list, &c->orph_list);
+ list_add_tail(&orphan->new_list, &c->orph_new);
+
+ if (parent_orphan) {
+ list_add_tail(&orphan->child_list,
+ &parent_orphan->child_list);
+ }
+
+ spin_unlock(&c->orphan_lock);
+ dbg_gen("ino %lu", (unsigned long)inum);
+ return orphan;
+}
+
+static struct ubifs_orphan *lookup_orphan(struct ubifs_info *c, ino_t inum)
+{
+ struct ubifs_orphan *o;
+ struct rb_node *p;
+
+ p = c->orph_tree.rb_node;
+ while (p) {
+ o = rb_entry(p, struct ubifs_orphan, rb);
+ if (inum < o->inum)
+ p = p->rb_left;
+ else if (inum > o->inum)
+ p = p->rb_right;
+ else {
+ return o;
+ }
+ }
+ return NULL;
+}
+
+static void __orphan_drop(struct ubifs_info *c, struct ubifs_orphan *o)
+{
+ rb_erase(&o->rb, &c->orph_tree);
+ list_del(&o->list);
+ c->tot_orphans -= 1;
+
+ if (o->new) {
+ list_del(&o->new_list);
+ c->new_orphans -= 1;
+ }
+
+ kfree(o);
+}
+
+static void orphan_delete(struct ubifs_info *c, struct ubifs_orphan *orph)
+{
+ if (orph->del) {
+ dbg_gen("deleted twice ino %lu", (unsigned long)orph->inum);
+ return;
+ }
+
+ if (orph->cmt) {
+ orph->del = 1;
+ orph->dnext = c->orph_dnext;
+ c->orph_dnext = orph;
+ dbg_gen("delete later ino %lu", (unsigned long)orph->inum);
+ return;
+ }
+
+ __orphan_drop(c, orph);
+}
+
+/**
+ * ubifs_add_orphan - add an orphan.
+ * @c: UBIFS file-system description object
+ * @inum: orphan inode number
+ *
+ * Add an orphan. This function is called when an inodes link count drops to
+ * zero.
+ */
+int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
+{
+ int err = 0;
+ ino_t xattr_inum;
+ union ubifs_key key;
+ struct ubifs_dent_node *xent, *pxent = NULL;
+ struct fscrypt_name nm = {0};
+ struct ubifs_orphan *xattr_orphan;
+ struct ubifs_orphan *orphan;
+
+ orphan = orphan_add(c, inum, NULL);
+ if (IS_ERR(orphan))
+ return PTR_ERR(orphan);
+
+ lowest_xent_key(c, &key, inum);
+ while (1) {
+ xent = ubifs_tnc_next_ent(c, &key, &nm);
+ if (IS_ERR(xent)) {
+ err = PTR_ERR(xent);
+ if (err == -ENOENT)
+ break;
+ kfree(pxent);
+ return err;
+ }
+
+ fname_name(&nm) = xent->name;
+ fname_len(&nm) = le16_to_cpu(xent->nlen);
+ xattr_inum = le64_to_cpu(xent->inum);
+
+ xattr_orphan = orphan_add(c, xattr_inum, orphan);
+ if (IS_ERR(xattr_orphan)) {
+ kfree(pxent);
+ kfree(xent);
+ return PTR_ERR(xattr_orphan);
+ }
+
+ kfree(pxent);
+ pxent = xent;
+ key_read(c, &xent->key, &key);
+ }
+ kfree(pxent);
+
+ return 0;
+}
+
+/**
+ * ubifs_delete_orphan - delete an orphan.
+ * @c: UBIFS file-system description object
+ * @inum: orphan inode number
+ *
+ * Delete an orphan. This function is called when an inode is deleted.
+ */
+void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
+{
+ struct ubifs_orphan *orph, *child_orph, *tmp_o;
+
+ spin_lock(&c->orphan_lock);
+
+ orph = lookup_orphan(c, inum);
+ if (!orph) {
+ spin_unlock(&c->orphan_lock);
+ ubifs_err(c, "missing orphan ino %lu", (unsigned long)inum);
+ dump_stack();
+
+ return;
+ }
+
+ list_for_each_entry_safe(child_orph, tmp_o, &orph->child_list, child_list) {
+ list_del(&child_orph->child_list);
+ orphan_delete(c, child_orph);
+ }
+
+ orphan_delete(c, orph);
+
+ spin_unlock(&c->orphan_lock);
+}
+
+/**
+ * ubifs_orphan_start_commit - start commit of orphans.
+ * @c: UBIFS file-system description object
+ *
+ * Start commit of orphans.
+ */
+int ubifs_orphan_start_commit(struct ubifs_info *c)
+{
+ struct ubifs_orphan *orphan, **last;
+
+ spin_lock(&c->orphan_lock);
+ last = &c->orph_cnext;
+ list_for_each_entry(orphan, &c->orph_new, new_list) {
+ ubifs_assert(c, orphan->new);
+ ubifs_assert(c, !orphan->cmt);
+ orphan->new = 0;
+ orphan->cmt = 1;
+ *last = orphan;
+ last = &orphan->cnext;
+ }
+ *last = NULL;
+ c->cmt_orphans = c->new_orphans;
+ c->new_orphans = 0;
+ dbg_cmt("%d orphans to commit", c->cmt_orphans);
+ INIT_LIST_HEAD(&c->orph_new);
+ if (c->tot_orphans == 0)
+ c->no_orphs = 1;
+ else
+ c->no_orphs = 0;
+ spin_unlock(&c->orphan_lock);
+ return 0;
+}
+
+/**
+ * avail_orphs - calculate available space.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns the number of orphans that can be written in the
+ * available space.
+ */
+static int avail_orphs(struct ubifs_info *c)
+{
+ int avail_lebs, avail, gap;
+
+ avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1;
+ avail = avail_lebs *
+ ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
+ gap = c->leb_size - c->ohead_offs;
+ if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64))
+ avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
+ return avail;
+}
+
+/**
+ * tot_avail_orphs - calculate total space.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns the number of orphans that can be written in half
+ * the total space. That leaves half the space for adding new orphans.
+ */
+static int tot_avail_orphs(struct ubifs_info *c)
+{
+ int avail_lebs, avail;
+
+ avail_lebs = c->orph_lebs;
+ avail = avail_lebs *
+ ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
+ return avail / 2;
+}
+
+/**
+ * do_write_orph_node - write a node to the orphan head.
+ * @c: UBIFS file-system description object
+ * @len: length of node
+ * @atomic: write atomically
+ *
+ * This function writes a node to the orphan head from the orphan buffer. If
+ * %atomic is not zero, then the write is done atomically. On success, %0 is
+ * returned, otherwise a negative error code is returned.
+ */
+static int do_write_orph_node(struct ubifs_info *c, int len, int atomic)
+{
+ int err = 0;
+
+ if (atomic) {
+ ubifs_assert(c, c->ohead_offs == 0);
+ ubifs_prepare_node(c, c->orph_buf, len, 1);
+ len = ALIGN(len, c->min_io_size);
+ err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len);
+ } else {
+ if (c->ohead_offs == 0) {
+ /* Ensure LEB has been unmapped */
+ err = ubifs_leb_unmap(c, c->ohead_lnum);
+ if (err)
+ return err;
+ }
+ err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum,
+ c->ohead_offs);
+ }
+ return err;
+}
+
+/**
+ * write_orph_node - write an orphan node.
+ * @c: UBIFS file-system description object
+ * @atomic: write atomically
+ *
+ * This function builds an orphan node from the cnext list and writes it to the
+ * orphan head. On success, %0 is returned, otherwise a negative error code
+ * is returned.
+ */
+static int write_orph_node(struct ubifs_info *c, int atomic)
+{
+ struct ubifs_orphan *orphan, *cnext;
+ struct ubifs_orph_node *orph;
+ int gap, err, len, cnt, i;
+
+ ubifs_assert(c, c->cmt_orphans > 0);
+ gap = c->leb_size - c->ohead_offs;
+ if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) {
+ c->ohead_lnum += 1;
+ c->ohead_offs = 0;
+ gap = c->leb_size;
+ if (c->ohead_lnum > c->orph_last) {
+ /*
+ * We limit the number of orphans so that this should
+ * never happen.
+ */
+ ubifs_err(c, "out of space in orphan area");
+ return -EINVAL;
+ }
+ }
+ cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
+ if (cnt > c->cmt_orphans)
+ cnt = c->cmt_orphans;
+ len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64);
+ ubifs_assert(c, c->orph_buf);
+ orph = c->orph_buf;
+ orph->ch.node_type = UBIFS_ORPH_NODE;
+ spin_lock(&c->orphan_lock);
+ cnext = c->orph_cnext;
+ for (i = 0; i < cnt; i++) {
+ orphan = cnext;
+ ubifs_assert(c, orphan->cmt);
+ orph->inos[i] = cpu_to_le64(orphan->inum);
+ orphan->cmt = 0;
+ cnext = orphan->cnext;
+ orphan->cnext = NULL;
+ }
+ c->orph_cnext = cnext;
+ c->cmt_orphans -= cnt;
+ spin_unlock(&c->orphan_lock);
+ if (c->cmt_orphans)
+ orph->cmt_no = cpu_to_le64(c->cmt_no);
+ else
+ /* Mark the last node of the commit */
+ orph->cmt_no = cpu_to_le64((c->cmt_no) | (1ULL << 63));
+ ubifs_assert(c, c->ohead_offs + len <= c->leb_size);
+ ubifs_assert(c, c->ohead_lnum >= c->orph_first);
+ ubifs_assert(c, c->ohead_lnum <= c->orph_last);
+ err = do_write_orph_node(c, len, atomic);
+ c->ohead_offs += ALIGN(len, c->min_io_size);
+ c->ohead_offs = ALIGN(c->ohead_offs, 8);
+ return err;
+}
+
+/**
+ * write_orph_nodes - write orphan nodes until there are no more to commit.
+ * @c: UBIFS file-system description object
+ * @atomic: write atomically
+ *
+ * This function writes orphan nodes for all the orphans to commit. On success,
+ * %0 is returned, otherwise a negative error code is returned.
+ */
+static int write_orph_nodes(struct ubifs_info *c, int atomic)
+{
+ int err;
+
+ while (c->cmt_orphans > 0) {
+ err = write_orph_node(c, atomic);
+ if (err)
+ return err;
+ }
+ if (atomic) {
+ int lnum;
+
+ /* Unmap any unused LEBs after consolidation */
+ for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ }
+ return 0;
+}
+
+/**
+ * consolidate - consolidate the orphan area.
+ * @c: UBIFS file-system description object
+ *
+ * This function enables consolidation by putting all the orphans into the list
+ * to commit. The list is in the order that the orphans were added, and the
+ * LEBs are written atomically in order, so at no time can orphans be lost by
+ * an unclean unmount.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int consolidate(struct ubifs_info *c)
+{
+ int tot_avail = tot_avail_orphs(c), err = 0;
+
+ spin_lock(&c->orphan_lock);
+ dbg_cmt("there is space for %d orphans and there are %d",
+ tot_avail, c->tot_orphans);
+ if (c->tot_orphans - c->new_orphans <= tot_avail) {
+ struct ubifs_orphan *orphan, **last;
+ int cnt = 0;
+
+ /* Change the cnext list to include all non-new orphans */
+ last = &c->orph_cnext;
+ list_for_each_entry(orphan, &c->orph_list, list) {
+ if (orphan->new)
+ continue;
+ orphan->cmt = 1;
+ *last = orphan;
+ last = &orphan->cnext;
+ cnt += 1;
+ }
+ *last = NULL;
+ ubifs_assert(c, cnt == c->tot_orphans - c->new_orphans);
+ c->cmt_orphans = cnt;
+ c->ohead_lnum = c->orph_first;
+ c->ohead_offs = 0;
+ } else {
+ /*
+ * We limit the number of orphans so that this should
+ * never happen.
+ */
+ ubifs_err(c, "out of space in orphan area");
+ err = -EINVAL;
+ }
+ spin_unlock(&c->orphan_lock);
+ return err;
+}
+
+/**
+ * commit_orphans - commit orphans.
+ * @c: UBIFS file-system description object
+ *
+ * This function commits orphans to flash. On success, %0 is returned,
+ * otherwise a negative error code is returned.
+ */
+static int commit_orphans(struct ubifs_info *c)
+{
+ int avail, atomic = 0, err;
+
+ ubifs_assert(c, c->cmt_orphans > 0);
+ avail = avail_orphs(c);
+ if (avail < c->cmt_orphans) {
+ /* Not enough space to write new orphans, so consolidate */
+ err = consolidate(c);
+ if (err)
+ return err;
+ atomic = 1;
+ }
+ err = write_orph_nodes(c, atomic);
+ return err;
+}
+
+/**
+ * erase_deleted - erase the orphans marked for deletion.
+ * @c: UBIFS file-system description object
+ *
+ * During commit, the orphans being committed cannot be deleted, so they are
+ * marked for deletion and deleted by this function. Also, the recovery
+ * adds killed orphans to the deletion list, and therefore they are deleted
+ * here too.
+ */
+static void erase_deleted(struct ubifs_info *c)
+{
+ struct ubifs_orphan *orphan, *dnext;
+
+ spin_lock(&c->orphan_lock);
+ dnext = c->orph_dnext;
+ while (dnext) {
+ orphan = dnext;
+ dnext = orphan->dnext;
+ ubifs_assert(c, !orphan->new);
+ ubifs_assert(c, orphan->del);
+ rb_erase(&orphan->rb, &c->orph_tree);
+ list_del(&orphan->list);
+ c->tot_orphans -= 1;
+ dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum);
+ kfree(orphan);
+ }
+ c->orph_dnext = NULL;
+ spin_unlock(&c->orphan_lock);
+}
+
+/**
+ * ubifs_orphan_end_commit - end commit of orphans.
+ * @c: UBIFS file-system description object
+ *
+ * End commit of orphans.
+ */
+int ubifs_orphan_end_commit(struct ubifs_info *c)
+{
+ int err;
+
+ if (c->cmt_orphans != 0) {
+ err = commit_orphans(c);
+ if (err)
+ return err;
+ }
+ erase_deleted(c);
+ err = dbg_check_orphans(c);
+ return err;
+}
+
+/**
+ * ubifs_clear_orphans - erase all LEBs used for orphans.
+ * @c: UBIFS file-system description object
+ *
+ * If recovery is not required, then the orphans from the previous session
+ * are not needed. This function locates the LEBs used to record
+ * orphans, and un-maps them.
+ */
+int ubifs_clear_orphans(struct ubifs_info *c)
+{
+ int lnum, err;
+
+ for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ c->ohead_lnum = c->orph_first;
+ c->ohead_offs = 0;
+ return 0;
+}
+
+/**
+ * insert_dead_orphan - insert an orphan.
+ * @c: UBIFS file-system description object
+ * @inum: orphan inode number
+ *
+ * This function is a helper to the 'do_kill_orphans()' function. The orphan
+ * must be kept until the next commit, so it is added to the rb-tree and the
+ * deletion list.
+ */
+static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
+{
+ struct ubifs_orphan *orphan, *o;
+ struct rb_node **p, *parent = NULL;
+
+ orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
+ if (!orphan)
+ return -ENOMEM;
+ orphan->inum = inum;
+
+ p = &c->orph_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ o = rb_entry(parent, struct ubifs_orphan, rb);
+ if (inum < o->inum)
+ p = &(*p)->rb_left;
+ else if (inum > o->inum)
+ p = &(*p)->rb_right;
+ else {
+ /* Already added - no problem */
+ kfree(orphan);
+ return 0;
+ }
+ }
+ c->tot_orphans += 1;
+ rb_link_node(&orphan->rb, parent, p);
+ rb_insert_color(&orphan->rb, &c->orph_tree);
+ list_add_tail(&orphan->list, &c->orph_list);
+ orphan->del = 1;
+ orphan->dnext = c->orph_dnext;
+ c->orph_dnext = orphan;
+ dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
+ c->new_orphans, c->tot_orphans);
+ return 0;
+}
+
+/**
+ * do_kill_orphans - remove orphan inodes from the index.
+ * @c: UBIFS file-system description object
+ * @sleb: scanned LEB
+ * @last_cmt_no: cmt_no of last orphan node read is passed and returned here
+ * @outofdate: whether the LEB is out of date is returned here
+ * @last_flagged: whether the end orphan node is encountered
+ *
+ * This function is a helper to the 'kill_orphans()' function. It goes through
+ * every orphan node in a LEB and for every inode number recorded, removes
+ * all keys for that inode from the TNC.
+ */
+static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
+ unsigned long long *last_cmt_no, int *outofdate,
+ int *last_flagged)
+{
+ struct ubifs_scan_node *snod;
+ struct ubifs_orph_node *orph;
+ struct ubifs_ino_node *ino = NULL;
+ unsigned long long cmt_no;
+ ino_t inum;
+ int i, n, err, first = 1;
+
+ ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
+ if (!ino)
+ return -ENOMEM;
+
+ list_for_each_entry(snod, &sleb->nodes, list) {
+ if (snod->type != UBIFS_ORPH_NODE) {
+ ubifs_err(c, "invalid node type %d in orphan area at %d:%d",
+ snod->type, sleb->lnum, snod->offs);
+ ubifs_dump_node(c, snod->node);
+ err = -EINVAL;
+ goto out_free;
+ }
+
+ orph = snod->node;
+
+ /* Check commit number */
+ cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
+ /*
+ * The commit number on the master node may be less, because
+ * of a failed commit. If there are several failed commits in a
+ * row, the commit number written on orphan nodes will continue
+ * to increase (because the commit number is adjusted here) even
+ * though the commit number on the master node stays the same
+ * because the master node has not been re-written.
+ */
+ if (cmt_no > c->cmt_no)
+ c->cmt_no = cmt_no;
+ if (cmt_no < *last_cmt_no && *last_flagged) {
+ /*
+ * The last orphan node had a higher commit number and
+ * was flagged as the last written for that commit
+ * number. That makes this orphan node, out of date.
+ */
+ if (!first) {
+ ubifs_err(c, "out of order commit number %llu in orphan node at %d:%d",
+ cmt_no, sleb->lnum, snod->offs);
+ ubifs_dump_node(c, snod->node);
+ err = -EINVAL;
+ goto out_free;
+ }
+ dbg_rcvry("out of date LEB %d", sleb->lnum);
+ *outofdate = 1;
+ err = 0;
+ goto out_free;
+ }
+
+ if (first)
+ first = 0;
+
+ n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
+ for (i = 0; i < n; i++) {
+ union ubifs_key key1, key2;
+
+ inum = le64_to_cpu(orph->inos[i]);
+
+ ino_key_init(c, &key1, inum);
+ err = ubifs_tnc_lookup(c, &key1, ino);
+ if (err && err != -ENOENT)
+ goto out_free;
+
+ /*
+ * Check whether an inode can really get deleted.
+ * linkat() with O_TMPFILE allows rebirth of an inode.
+ */
+ if (err == 0 && ino->nlink == 0) {
+ dbg_rcvry("deleting orphaned inode %lu",
+ (unsigned long)inum);
+
+ lowest_ino_key(c, &key1, inum);
+ highest_ino_key(c, &key2, inum);
+
+ err = ubifs_tnc_remove_range(c, &key1, &key2);
+ if (err)
+ goto out_ro;
+ }
+
+ err = insert_dead_orphan(c, inum);
+ if (err)
+ goto out_free;
+ }
+
+ *last_cmt_no = cmt_no;
+ if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
+ dbg_rcvry("last orph node for commit %llu at %d:%d",
+ cmt_no, sleb->lnum, snod->offs);
+ *last_flagged = 1;
+ } else
+ *last_flagged = 0;
+ }
+
+ err = 0;
+out_free:
+ kfree(ino);
+ return err;
+
+out_ro:
+ ubifs_ro_mode(c, err);
+ kfree(ino);
+ return err;
+}
+
+/**
+ * kill_orphans - remove all orphan inodes from the index.
+ * @c: UBIFS file-system description object
+ *
+ * If recovery is required, then orphan inodes recorded during the previous
+ * session (which ended with an unclean unmount) must be deleted from the index.
+ * This is done by updating the TNC, but since the index is not updated until
+ * the next commit, the LEBs where the orphan information is recorded are not
+ * erased until the next commit.
+ */
+static int kill_orphans(struct ubifs_info *c)
+{
+ unsigned long long last_cmt_no = 0;
+ int lnum, err = 0, outofdate = 0, last_flagged = 0;
+
+ c->ohead_lnum = c->orph_first;
+ c->ohead_offs = 0;
+ /* Check no-orphans flag and skip this if no orphans */
+ if (c->no_orphs) {
+ dbg_rcvry("no orphans");
+ return 0;
+ }
+ /*
+ * Orph nodes always start at c->orph_first and are written to each
+ * successive LEB in turn. Generally unused LEBs will have been unmapped
+ * but may contain out of date orphan nodes if the unmap didn't go
+ * through. In addition, the last orphan node written for each commit is
+ * marked (top bit of orph->cmt_no is set to 1). It is possible that
+ * there are orphan nodes from the next commit (i.e. the commit did not
+ * complete successfully). In that case, no orphans will have been lost
+ * due to the way that orphans are written, and any orphans added will
+ * be valid orphans anyway and so can be deleted.
+ */
+ for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
+ struct ubifs_scan_leb *sleb;
+
+ dbg_rcvry("LEB %d", lnum);
+ sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
+ if (IS_ERR(sleb)) {
+ if (PTR_ERR(sleb) == -EUCLEAN)
+ sleb = ubifs_recover_leb(c, lnum, 0,
+ c->sbuf, -1);
+ if (IS_ERR(sleb)) {
+ err = PTR_ERR(sleb);
+ break;
+ }
+ }
+ err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
+ &last_flagged);
+ if (err || outofdate) {
+ ubifs_scan_destroy(sleb);
+ break;
+ }
+ if (sleb->endpt) {
+ c->ohead_lnum = lnum;
+ c->ohead_offs = sleb->endpt;
+ }
+ ubifs_scan_destroy(sleb);
+ }
+ return err;
+}
+
+/**
+ * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
+ * @c: UBIFS file-system description object
+ * @unclean: indicates recovery from unclean unmount
+ * @read_only: indicates read only mount
+ *
+ * This function is called when mounting to erase orphans from the previous
+ * session. If UBIFS was not unmounted cleanly, then the inodes recorded as
+ * orphans are deleted.
+ */
+int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
+{
+ int err = 0;
+
+ c->max_orphans = tot_avail_orphs(c);
+
+ if (!read_only) {
+ c->orph_buf = vmalloc(c->leb_size);
+ if (!c->orph_buf)
+ return -ENOMEM;
+ }
+
+ if (unclean)
+ err = kill_orphans(c);
+ else if (!read_only)
+ err = ubifs_clear_orphans(c);
+
+ return err;
+}
+
+/*
+ * Everything below is related to debugging.
+ */
+
+struct check_orphan {
+ struct rb_node rb;
+ ino_t inum;
+};
+
+struct check_info {
+ unsigned long last_ino;
+ unsigned long tot_inos;
+ unsigned long missing;
+ unsigned long long leaf_cnt;
+ struct ubifs_ino_node *node;
+ struct rb_root root;
+};
+
+static bool dbg_find_orphan(struct ubifs_info *c, ino_t inum)
+{
+ bool found = false;
+
+ spin_lock(&c->orphan_lock);
+ found = !!lookup_orphan(c, inum);
+ spin_unlock(&c->orphan_lock);
+
+ return found;
+}
+
+static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
+{
+ struct check_orphan *orphan, *o;
+ struct rb_node **p, *parent = NULL;
+
+ orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
+ if (!orphan)
+ return -ENOMEM;
+ orphan->inum = inum;
+
+ p = &root->rb_node;
+ while (*p) {
+ parent = *p;
+ o = rb_entry(parent, struct check_orphan, rb);
+ if (inum < o->inum)
+ p = &(*p)->rb_left;
+ else if (inum > o->inum)
+ p = &(*p)->rb_right;
+ else {
+ kfree(orphan);
+ return 0;
+ }
+ }
+ rb_link_node(&orphan->rb, parent, p);
+ rb_insert_color(&orphan->rb, root);
+ return 0;
+}
+
+static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
+{
+ struct check_orphan *o;
+ struct rb_node *p;
+
+ p = root->rb_node;
+ while (p) {
+ o = rb_entry(p, struct check_orphan, rb);
+ if (inum < o->inum)
+ p = p->rb_left;
+ else if (inum > o->inum)
+ p = p->rb_right;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+static void dbg_free_check_tree(struct rb_root *root)
+{
+ struct check_orphan *o, *n;
+
+ rbtree_postorder_for_each_entry_safe(o, n, root, rb)
+ kfree(o);
+}
+
+static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
+ void *priv)
+{
+ struct check_info *ci = priv;
+ ino_t inum;
+ int err;
+
+ inum = key_inum(c, &zbr->key);
+ if (inum != ci->last_ino) {
+ /* Lowest node type is the inode node, so it comes first */
+ if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
+ ubifs_err(c, "found orphan node ino %lu, type %d",
+ (unsigned long)inum, key_type(c, &zbr->key));
+ ci->last_ino = inum;
+ ci->tot_inos += 1;
+ err = ubifs_tnc_read_node(c, zbr, ci->node);
+ if (err) {
+ ubifs_err(c, "node read failed, error %d", err);
+ return err;
+ }
+ if (ci->node->nlink == 0)
+ /* Must be recorded as an orphan */
+ if (!dbg_find_check_orphan(&ci->root, inum) &&
+ !dbg_find_orphan(c, inum)) {
+ ubifs_err(c, "missing orphan, ino %lu",
+ (unsigned long)inum);
+ ci->missing += 1;
+ }
+ }
+ ci->leaf_cnt += 1;
+ return 0;
+}
+
+static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
+{
+ struct ubifs_scan_node *snod;
+ struct ubifs_orph_node *orph;
+ ino_t inum;
+ int i, n, err;
+
+ list_for_each_entry(snod, &sleb->nodes, list) {
+ cond_resched();
+ if (snod->type != UBIFS_ORPH_NODE)
+ continue;
+ orph = snod->node;
+ n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
+ for (i = 0; i < n; i++) {
+ inum = le64_to_cpu(orph->inos[i]);
+ err = dbg_ins_check_orphan(&ci->root, inum);
+ if (err)
+ return err;
+ }
+ }
+ return 0;
+}
+
+static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
+{
+ int lnum, err = 0;
+ void *buf;
+
+ /* Check no-orphans flag and skip this if no orphans */
+ if (c->no_orphs)
+ return 0;
+
+ buf = __vmalloc(c->leb_size, GFP_NOFS);
+ if (!buf) {
+ ubifs_err(c, "cannot allocate memory to check orphans");
+ return 0;
+ }
+
+ for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
+ struct ubifs_scan_leb *sleb;
+
+ sleb = ubifs_scan(c, lnum, 0, buf, 0);
+ if (IS_ERR(sleb)) {
+ err = PTR_ERR(sleb);
+ break;
+ }
+
+ err = dbg_read_orphans(ci, sleb);
+ ubifs_scan_destroy(sleb);
+ if (err)
+ break;
+ }
+
+ vfree(buf);
+ return err;
+}
+
+static int dbg_check_orphans(struct ubifs_info *c)
+{
+ struct check_info ci;
+ int err;
+
+ if (!dbg_is_chk_orph(c))
+ return 0;
+
+ ci.last_ino = 0;
+ ci.tot_inos = 0;
+ ci.missing = 0;
+ ci.leaf_cnt = 0;
+ ci.root = RB_ROOT;
+ ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
+ if (!ci.node) {
+ ubifs_err(c, "out of memory");
+ return -ENOMEM;
+ }
+
+ err = dbg_scan_orphans(c, &ci);
+ if (err)
+ goto out;
+
+ err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
+ if (err) {
+ ubifs_err(c, "cannot scan TNC, error %d", err);
+ goto out;
+ }
+
+ if (ci.missing) {
+ ubifs_err(c, "%lu missing orphan(s)", ci.missing);
+ err = -EINVAL;
+ goto out;
+ }
+
+ dbg_cmt("last inode number is %lu", ci.last_ino);
+ dbg_cmt("total number of inodes is %lu", ci.tot_inos);
+ dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
+
+out:
+ dbg_free_check_tree(&ci.root);
+ kfree(ci.node);
+ return err;
+}