1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * BTRFS filesystem implementation for U-Boot
4 *
5 * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
6 */
7
8 #include "btrfs.h"
9 #include <malloc.h>
10
btrfs_read_extent_inline(struct btrfs_path * path,struct btrfs_file_extent_item * extent,u64 offset,u64 size,char * out)11 u64 btrfs_read_extent_inline(struct btrfs_path *path,
12 struct btrfs_file_extent_item *extent, u64 offset,
13 u64 size, char *out)
14 {
15 u32 clen, dlen, orig_size = size, res;
16 const char *cbuf;
17 char *dbuf;
18 const int data_off = offsetof(struct btrfs_file_extent_item,
19 disk_bytenr);
20
21 clen = btrfs_path_item_size(path) - data_off;
22 cbuf = (const char *) extent + data_off;
23 dlen = extent->ram_bytes;
24
25 if (offset > dlen)
26 return -1ULL;
27
28 if (size > dlen - offset)
29 size = dlen - offset;
30
31 if (extent->compression == BTRFS_COMPRESS_NONE) {
32 memcpy(out, cbuf + offset, size);
33 return size;
34 }
35
36 if (dlen > orig_size) {
37 dbuf = malloc(dlen);
38 if (!dbuf)
39 return -1ULL;
40 } else {
41 dbuf = out;
42 }
43
44 res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
45 if (res == -1 || res != dlen)
46 goto err;
47
48 if (dlen > orig_size) {
49 memcpy(out, dbuf + offset, size);
50 free(dbuf);
51 } else if (offset) {
52 memmove(out, dbuf + offset, size);
53 }
54
55 return size;
56
57 err:
58 if (dlen > orig_size)
59 free(dbuf);
60 return -1ULL;
61 }
62
btrfs_read_extent_reg(struct btrfs_path * path,struct btrfs_file_extent_item * extent,u64 offset,u64 size,char * out)63 u64 btrfs_read_extent_reg(struct btrfs_path *path,
64 struct btrfs_file_extent_item *extent, u64 offset,
65 u64 size, char *out)
66 {
67 u64 physical, clen, dlen, orig_size = size;
68 u32 res;
69 char *cbuf, *dbuf;
70
71 clen = extent->disk_num_bytes;
72 dlen = extent->num_bytes;
73
74 if (offset > dlen)
75 return -1ULL;
76
77 if (size > dlen - offset)
78 size = dlen - offset;
79
80 physical = btrfs_map_logical_to_physical(extent->disk_bytenr);
81 if (physical == -1ULL)
82 return -1ULL;
83
84 if (extent->compression == BTRFS_COMPRESS_NONE) {
85 physical += extent->offset + offset;
86 if (!btrfs_devread(physical, size, out))
87 return -1ULL;
88
89 return size;
90 }
91
92 cbuf = malloc(dlen > size ? clen + dlen : clen);
93 if (!cbuf)
94 return -1ULL;
95
96 if (dlen > orig_size)
97 dbuf = cbuf + clen;
98 else
99 dbuf = out;
100
101 if (!btrfs_devread(physical, clen, cbuf))
102 goto err;
103
104 res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
105 if (res == -1)
106 goto err;
107
108 if (dlen > orig_size)
109 memcpy(out, dbuf + offset, size);
110 else
111 memmove(out, dbuf + offset, size);
112
113 free(cbuf);
114 return res;
115
116 err:
117 free(cbuf);
118 return -1ULL;
119 }
120