blob: 68a9bd98f8ca5a8a9576ad412a068968b53b7c62 [file] [log] [blame]
Stefan Roese2fc10f62009-03-19 15:35:05 +01001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
21 */
22
23/*
24 * This file is a part of UBIFS journal implementation and contains various
25 * functions which manipulate the log. The log is a fixed area on the flash
26 * which does not contain any data but refers to buds. The log is a part of the
27 * journal.
28 */
29
30#include "ubifs.h"
31
32/**
33 * ubifs_search_bud - search bud LEB.
34 * @c: UBIFS file-system description object
35 * @lnum: logical eraseblock number to search
36 *
37 * This function searches bud LEB @lnum. Returns bud description object in case
38 * of success and %NULL if there is no bud with this LEB number.
39 */
40struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
41{
42 struct rb_node *p;
43 struct ubifs_bud *bud;
44
45 spin_lock(&c->buds_lock);
46 p = c->buds.rb_node;
47 while (p) {
48 bud = rb_entry(p, struct ubifs_bud, rb);
49 if (lnum < bud->lnum)
50 p = p->rb_left;
51 else if (lnum > bud->lnum)
52 p = p->rb_right;
53 else {
54 spin_unlock(&c->buds_lock);
55 return bud;
56 }
57 }
58 spin_unlock(&c->buds_lock);
59 return NULL;
60}
61
62/**
63 * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
64 * @c: UBIFS file-system description object
65 * @bud: the bud to add
66 */
67void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
68{
69 struct rb_node **p, *parent = NULL;
70 struct ubifs_bud *b;
71 struct ubifs_jhead *jhead;
72
73 spin_lock(&c->buds_lock);
74 p = &c->buds.rb_node;
75 while (*p) {
76 parent = *p;
77 b = rb_entry(parent, struct ubifs_bud, rb);
78 ubifs_assert(bud->lnum != b->lnum);
79 if (bud->lnum < b->lnum)
80 p = &(*p)->rb_left;
81 else
82 p = &(*p)->rb_right;
83 }
84
85 rb_link_node(&bud->rb, parent, p);
86 rb_insert_color(&bud->rb, &c->buds);
87 if (c->jheads) {
88 jhead = &c->jheads[bud->jhead];
89 list_add_tail(&bud->list, &jhead->buds_list);
90 } else
91 ubifs_assert(c->replaying && (c->vfs_sb->s_flags & MS_RDONLY));
92
93 /*
94 * Note, although this is a new bud, we anyway account this space now,
95 * before any data has been written to it, because this is about to
96 * guarantee fixed mount time, and this bud will anyway be read and
97 * scanned.
98 */
99 c->bud_bytes += c->leb_size - bud->start;
100
101 dbg_log("LEB %d:%d, jhead %d, bud_bytes %lld", bud->lnum,
102 bud->start, bud->jhead, c->bud_bytes);
103 spin_unlock(&c->buds_lock);
104}