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