diff options
Diffstat (limited to 'fs/ubifs/orphan.c')
| -rw-r--r-- | fs/ubifs/orphan.c | 1052 |
1 files changed, 1052 insertions, 0 deletions
diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c new file mode 100644 index 0000000000..4909321d84 --- /dev/null +++ b/fs/ubifs/orphan.c @@ -0,0 +1,1052 @@ +// 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, + c->leb_size - snod->offs); + 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, + c->leb_size - snod->offs); + 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; +} |