xref: /openbmc/u-boot/fs/ubifs/log.c (revision a89c33db)
1 /*
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  */
40 struct 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  */
67 void 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 }
105