]> git.sur5r.net Git - u-boot/blob - fs/ext4/dev.c
fs: ext4: fix symlink read function
[u-boot] / fs / ext4 / dev.c
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  * made from existing ext2/dev.c file of Uboot
8  * (C) Copyright 2004
9  * esd gmbh <www.esd-electronics.com>
10  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
11  *
12  * based on code of fs/reiserfs/dev.c by
13  *
14  * (C) Copyright 2003 - 2004
15  * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
16  *
17  * SPDX-License-Identifier:     GPL-2.0+
18  */
19
20 /*
21  * Changelog:
22  *      0.1 - Newly created file for ext4fs support. Taken from
23  *              fs/ext2/dev.c file in uboot.
24  */
25
26 #include <common.h>
27 #include <blk.h>
28 #include <config.h>
29 #include <memalign.h>
30 #include <ext4fs.h>
31 #include <ext_common.h>
32 #include "ext4_common.h"
33
34 lbaint_t part_offset;
35
36 static struct blk_desc *ext4fs_blk_desc;
37 static disk_partition_t *part_info;
38
39 void ext4fs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
40 {
41         assert(rbdd->blksz == (1 << rbdd->log2blksz));
42         ext4fs_blk_desc = rbdd;
43         get_fs()->dev_desc = rbdd;
44         part_info = info;
45         part_offset = info->start;
46         get_fs()->total_sect = ((uint64_t)info->size * info->blksz) >>
47                 get_fs()->dev_desc->log2blksz;
48 }
49
50 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
51 {
52         unsigned block_len;
53         int log2blksz = ext4fs_blk_desc->log2blksz;
54         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_blk_desc ?
55                                                  ext4fs_blk_desc->blksz :
56                                                  0));
57         if (ext4fs_blk_desc == NULL) {
58                 printf("** Invalid Block Device Descriptor (NULL)\n");
59                 return 0;
60         }
61
62         /* Check partition boundaries */
63         if ((sector < 0) ||
64             ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
65              >= part_info->size)) {
66                 printf("%s read outside partition " LBAFU "\n", __func__,
67                        sector);
68                 return 0;
69         }
70
71         /* Get the read to the beginning of a partition */
72         sector += byte_offset >> log2blksz;
73         byte_offset &= ext4fs_blk_desc->blksz - 1;
74
75         debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
76
77         if (byte_offset != 0) {
78                 int readlen;
79                 /* read first part which isn't aligned with start of sector */
80                 if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
81                               (void *)sec_buf) != 1) {
82                         printf(" ** ext2fs_devread() read error **\n");
83                         return 0;
84                 }
85                 readlen = min((int)ext4fs_blk_desc->blksz - byte_offset,
86                               byte_len);
87                 memcpy(buf, sec_buf + byte_offset, readlen);
88                 buf += readlen;
89                 byte_len -= readlen;
90                 sector++;
91         }
92
93         if (byte_len == 0)
94                 return 1;
95
96         /* read sector aligned part */
97         block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
98
99         if (block_len == 0) {
100                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_blk_desc->blksz);
101
102                 block_len = ext4fs_blk_desc->blksz;
103                 blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
104                           (void *)p);
105                 memcpy(buf, p, byte_len);
106                 return 1;
107         }
108
109         if (blk_dread(ext4fs_blk_desc, part_info->start + sector,
110                       block_len >> log2blksz, (void *)buf) !=
111                         block_len >> log2blksz) {
112                 printf(" ** %s read error - block\n", __func__);
113                 return 0;
114         }
115         block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
116         buf += block_len;
117         byte_len -= block_len;
118         sector += block_len / ext4fs_blk_desc->blksz;
119
120         if (byte_len != 0) {
121                 /* read rest of data which are not in whole sector */
122                 if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
123                               (void *)sec_buf) != 1) {
124                         printf("* %s read error - last part\n", __func__);
125                         return 0;
126                 }
127                 memcpy(buf, sec_buf, byte_len);
128         }
129         return 1;
130 }
131
132 int ext4_read_superblock(char *buffer)
133 {
134         struct ext_filesystem *fs = get_fs();
135         int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
136         int off = SUPERBLOCK_START % fs->dev_desc->blksz;
137
138         return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
139                                 buffer);
140 }