xref: /openbmc/u-boot/fs/ext4/ext4fs.c (revision 8a00061e)
1 /*
2  * (C) Copyright 2011 - 2012 Samsung Electronics
3  * EXT4 filesystem implementation in Uboot by
4  * Uma Shankar <uma.shankar@samsung.com>
5  * Manjunatha C Achar <a.manjunatha@samsung.com>
6  *
7  * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
8  *		       Ext4 read optimization taken from Open-Moko
9  *		       Qi bootloader
10  *
11  * (C) Copyright 2004
12  * esd gmbh <www.esd-electronics.com>
13  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
14  *
15  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
16  * GRUB  --  GRand Unified Bootloader
17  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
18  *
19  * ext4write : Based on generic ext4 protocol.
20  *
21  * This program is free software; you can redistribute it and/or modify
22  * it under the terms of the GNU General Public License as published by
23  * the Free Software Foundation; either version 2 of the License, or
24  * (at your option) any later version.
25  *
26  * This program is distributed in the hope that it will be useful,
27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
29  * GNU General Public License for more details.
30  *
31  * You should have received a copy of the GNU General Public License
32  * along with this program; if not, write to the Free Software
33  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34  */
35 
36 #include <common.h>
37 #include <ext_common.h>
38 #include <ext4fs.h>
39 #include "ext4_common.h"
40 
41 int ext4fs_symlinknest;
42 struct ext_filesystem ext_fs;
43 
44 struct ext_filesystem *get_fs(void)
45 {
46 	return &ext_fs;
47 }
48 
49 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
50 {
51 	if ((node != &ext4fs_root->diropen) && (node != currroot))
52 		free(node);
53 }
54 
55 /*
56  * Taken from openmoko-kernel mailing list: By Andy green
57  * Optimized read file API : collects and defers contiguous sector
58  * reads into one potentially more efficient larger sequential read action
59  */
60 int ext4fs_read_file(struct ext2fs_node *node, int pos,
61 		unsigned int len, char *buf)
62 {
63 	int i;
64 	int blockcnt;
65 	int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
66 	int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
67 	unsigned int filesize = __le32_to_cpu(node->inode.size);
68 	int previous_block_number = -1;
69 	int delayed_start = 0;
70 	int delayed_extent = 0;
71 	int delayed_skipfirst = 0;
72 	int delayed_next = 0;
73 	char *delayed_buf = NULL;
74 	short status;
75 
76 	/* Adjust len so it we can't read past the end of the file. */
77 	if (len > filesize)
78 		len = filesize;
79 
80 	blockcnt = ((len + pos) + blocksize - 1) / blocksize;
81 
82 	for (i = pos / blocksize; i < blockcnt; i++) {
83 		int blknr;
84 		int blockoff = pos % blocksize;
85 		int blockend = blocksize;
86 		int skipfirst = 0;
87 		blknr = read_allocated_block(&(node->inode), i);
88 		if (blknr < 0)
89 			return -1;
90 
91 		blknr = blknr << log2blocksize;
92 
93 		/* Last block.  */
94 		if (i == blockcnt - 1) {
95 			blockend = (len + pos) % blocksize;
96 
97 			/* The last portion is exactly blocksize. */
98 			if (!blockend)
99 				blockend = blocksize;
100 		}
101 
102 		/* First block. */
103 		if (i == pos / blocksize) {
104 			skipfirst = blockoff;
105 			blockend -= skipfirst;
106 		}
107 		if (blknr) {
108 			int status;
109 
110 			if (previous_block_number != -1) {
111 				if (delayed_next == blknr) {
112 					delayed_extent += blockend;
113 					delayed_next += blockend >> SECTOR_BITS;
114 				} else {	/* spill */
115 					status = ext4fs_devread(delayed_start,
116 							delayed_skipfirst,
117 							delayed_extent,
118 							delayed_buf);
119 					if (status == 0)
120 						return -1;
121 					previous_block_number = blknr;
122 					delayed_start = blknr;
123 					delayed_extent = blockend;
124 					delayed_skipfirst = skipfirst;
125 					delayed_buf = buf;
126 					delayed_next = blknr +
127 						(blockend >> SECTOR_BITS);
128 				}
129 			} else {
130 				previous_block_number = blknr;
131 				delayed_start = blknr;
132 				delayed_extent = blockend;
133 				delayed_skipfirst = skipfirst;
134 				delayed_buf = buf;
135 				delayed_next = blknr +
136 					(blockend >> SECTOR_BITS);
137 			}
138 		} else {
139 			if (previous_block_number != -1) {
140 				/* spill */
141 				status = ext4fs_devread(delayed_start,
142 							delayed_skipfirst,
143 							delayed_extent,
144 							delayed_buf);
145 				if (status == 0)
146 					return -1;
147 				previous_block_number = -1;
148 			}
149 			memset(buf, 0, blocksize - skipfirst);
150 		}
151 		buf += blocksize - skipfirst;
152 	}
153 	if (previous_block_number != -1) {
154 		/* spill */
155 		status = ext4fs_devread(delayed_start,
156 					delayed_skipfirst, delayed_extent,
157 					delayed_buf);
158 		if (status == 0)
159 			return -1;
160 		previous_block_number = -1;
161 	}
162 
163 	return len;
164 }
165 
166 int ext4fs_ls(const char *dirname)
167 {
168 	struct ext2fs_node *dirnode;
169 	int status;
170 
171 	if (dirname == NULL)
172 		return 0;
173 
174 	status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
175 				  FILETYPE_DIRECTORY);
176 	if (status != 1) {
177 		printf("** Can not find directory. **\n");
178 		return 1;
179 	}
180 
181 	ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
182 	ext4fs_free_node(dirnode, &ext4fs_root->diropen);
183 
184 	return 0;
185 }
186 
187 int ext4fs_read(char *buf, unsigned len)
188 {
189 	if (ext4fs_root == NULL || ext4fs_file == NULL)
190 		return 0;
191 
192 	return ext4fs_read_file(ext4fs_file, 0, len, buf);
193 }
194 
195 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
196 		 disk_partition_t *fs_partition)
197 {
198 	ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
199 
200 	if (!ext4fs_mount(fs_partition->size)) {
201 		ext4fs_close();
202 		return -1;
203 	}
204 
205 	return 0;
206 }
207 
208 int ext4_read_file(const char *filename, void *buf, int offset, int len)
209 {
210 	int file_len;
211 	int len_read;
212 
213 	if (offset != 0) {
214 		printf("** Cannot support non-zero offset **\n");
215 		return -1;
216 	}
217 
218 	file_len = ext4fs_open(filename);
219 	if (file_len < 0) {
220 		printf("** File not found %s **\n", filename);
221 		return -1;
222 	}
223 
224 	if (len == 0)
225 		len = file_len;
226 
227 	len_read = ext4fs_read(buf, len);
228 
229 	return len_read;
230 }
231