xref: /openbmc/u-boot/fs/ext4/ext4fs.c (revision 7ca6f363)
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  * SPDX-License-Identifier:	GPL-2.0+
22  */
23 
24 #include <common.h>
25 #include <ext_common.h>
26 #include <ext4fs.h>
27 #include "ext4_common.h"
28 
29 int ext4fs_symlinknest;
30 struct ext_filesystem ext_fs;
31 
32 struct ext_filesystem *get_fs(void)
33 {
34 	return &ext_fs;
35 }
36 
37 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
38 {
39 	if ((node != &ext4fs_root->diropen) && (node != currroot))
40 		free(node);
41 }
42 
43 /*
44  * Taken from openmoko-kernel mailing list: By Andy green
45  * Optimized read file API : collects and defers contiguous sector
46  * reads into one potentially more efficient larger sequential read action
47  */
48 int ext4fs_read_file(struct ext2fs_node *node, int pos,
49 		unsigned int len, char *buf)
50 {
51 	struct ext_filesystem *fs = get_fs();
52 	int i;
53 	lbaint_t blockcnt;
54 	int log2blksz = fs->dev_desc->log2blksz;
55 	int log2_fs_blocksize = LOG2_BLOCK_SIZE(node->data) - log2blksz;
56 	int blocksize = (1 << (log2_fs_blocksize + log2blksz));
57 	unsigned int filesize = __le32_to_cpu(node->inode.size);
58 	lbaint_t previous_block_number = -1;
59 	lbaint_t delayed_start = 0;
60 	lbaint_t delayed_extent = 0;
61 	lbaint_t delayed_skipfirst = 0;
62 	lbaint_t delayed_next = 0;
63 	char *delayed_buf = NULL;
64 	short status;
65 
66 	/* Adjust len so it we can't read past the end of the file. */
67 	if (len > filesize)
68 		len = filesize;
69 
70 	blockcnt = ((len + pos) + blocksize - 1) / blocksize;
71 
72 	for (i = pos / blocksize; i < blockcnt; i++) {
73 		lbaint_t blknr;
74 		int blockoff = pos % blocksize;
75 		int blockend = blocksize;
76 		int skipfirst = 0;
77 		blknr = read_allocated_block(&(node->inode), i);
78 		if (blknr < 0)
79 			return -1;
80 
81 		blknr = blknr << log2_fs_blocksize;
82 
83 		/* Last block.  */
84 		if (i == blockcnt - 1) {
85 			blockend = (len + pos) % blocksize;
86 
87 			/* The last portion is exactly blocksize. */
88 			if (!blockend)
89 				blockend = blocksize;
90 		}
91 
92 		/* First block. */
93 		if (i == pos / blocksize) {
94 			skipfirst = blockoff;
95 			blockend -= skipfirst;
96 		}
97 		if (blknr) {
98 			int status;
99 
100 			if (previous_block_number != -1) {
101 				if (delayed_next == blknr) {
102 					delayed_extent += blockend;
103 					delayed_next += blockend >> log2blksz;
104 				} else {	/* spill */
105 					status = ext4fs_devread(delayed_start,
106 							delayed_skipfirst,
107 							delayed_extent,
108 							delayed_buf);
109 					if (status == 0)
110 						return -1;
111 					previous_block_number = blknr;
112 					delayed_start = blknr;
113 					delayed_extent = blockend;
114 					delayed_skipfirst = skipfirst;
115 					delayed_buf = buf;
116 					delayed_next = blknr +
117 						(blockend >> log2blksz);
118 				}
119 			} else {
120 				previous_block_number = blknr;
121 				delayed_start = blknr;
122 				delayed_extent = blockend;
123 				delayed_skipfirst = skipfirst;
124 				delayed_buf = buf;
125 				delayed_next = blknr +
126 					(blockend >> log2blksz);
127 			}
128 		} else {
129 			if (previous_block_number != -1) {
130 				/* spill */
131 				status = ext4fs_devread(delayed_start,
132 							delayed_skipfirst,
133 							delayed_extent,
134 							delayed_buf);
135 				if (status == 0)
136 					return -1;
137 				previous_block_number = -1;
138 			}
139 			memset(buf, 0, blocksize - skipfirst);
140 		}
141 		buf += blocksize - skipfirst;
142 	}
143 	if (previous_block_number != -1) {
144 		/* spill */
145 		status = ext4fs_devread(delayed_start,
146 					delayed_skipfirst, delayed_extent,
147 					delayed_buf);
148 		if (status == 0)
149 			return -1;
150 		previous_block_number = -1;
151 	}
152 
153 	return len;
154 }
155 
156 int ext4fs_ls(const char *dirname)
157 {
158 	struct ext2fs_node *dirnode;
159 	int status;
160 
161 	if (dirname == NULL)
162 		return 0;
163 
164 	status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
165 				  FILETYPE_DIRECTORY);
166 	if (status != 1) {
167 		printf("** Can not find directory. **\n");
168 		return 1;
169 	}
170 
171 	ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
172 	ext4fs_free_node(dirnode, &ext4fs_root->diropen);
173 
174 	return 0;
175 }
176 
177 int ext4fs_exists(const char *filename)
178 {
179 	int file_len;
180 
181 	file_len = ext4fs_open(filename);
182 	return file_len >= 0;
183 }
184 
185 int ext4fs_read(char *buf, unsigned len)
186 {
187 	if (ext4fs_root == NULL || ext4fs_file == NULL)
188 		return 0;
189 
190 	return ext4fs_read_file(ext4fs_file, 0, len, buf);
191 }
192 
193 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
194 		 disk_partition_t *fs_partition)
195 {
196 	ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
197 
198 	if (!ext4fs_mount(fs_partition->size)) {
199 		ext4fs_close();
200 		return -1;
201 	}
202 
203 	return 0;
204 }
205 
206 int ext4_read_file(const char *filename, void *buf, int offset, int len)
207 {
208 	int file_len;
209 	int len_read;
210 
211 	if (offset != 0) {
212 		printf("** Cannot support non-zero offset **\n");
213 		return -1;
214 	}
215 
216 	file_len = ext4fs_open(filename);
217 	if (file_len < 0) {
218 		printf("** File not found %s **\n", filename);
219 		return -1;
220 	}
221 
222 	if (len == 0)
223 		len = file_len;
224 
225 	len_read = ext4fs_read(buf, len);
226 
227 	return len_read;
228 }
229