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 #include <memalign.h>
11
btrfs_read_extent_inline(struct btrfs_path * path,struct btrfs_file_extent_item * extent,u64 offset,u64 size,char * out)12 u64 btrfs_read_extent_inline(struct btrfs_path *path,
13 struct btrfs_file_extent_item *extent, u64 offset,
14 u64 size, char *out)
15 {
16 u32 clen, dlen, orig_size = size, res;
17 const char *cbuf;
18 char *dbuf;
19 const int data_off = offsetof(struct btrfs_file_extent_item,
20 disk_bytenr);
21
22 clen = btrfs_path_item_size(path) - data_off;
23 cbuf = (const char *) extent + data_off;
24 dlen = extent->ram_bytes;
25
26 if (offset > dlen)
27 return -1ULL;
28
29 if (size > dlen - offset)
30 size = dlen - offset;
31
32 if (extent->compression == BTRFS_COMPRESS_NONE) {
33 memcpy(out, cbuf + offset, size);
34 return size;
35 }
36
37 if (dlen > orig_size) {
38 dbuf = malloc(dlen);
39 if (!dbuf)
40 return -1ULL;
41 } else {
42 dbuf = out;
43 }
44
45 res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
46 if (res == -1 || res != dlen)
47 goto err;
48
49 if (dlen > orig_size) {
50 memcpy(out, dbuf + offset, size);
51 free(dbuf);
52 } else if (offset) {
53 memmove(out, dbuf + offset, size);
54 }
55
56 return size;
57
58 err:
59 if (dlen > orig_size)
60 free(dbuf);
61 return -1ULL;
62 }
63
btrfs_read_extent_reg(struct btrfs_path * path,struct btrfs_file_extent_item * extent,u64 offset,u64 size,char * out)64 u64 btrfs_read_extent_reg(struct btrfs_path *path,
65 struct btrfs_file_extent_item *extent, u64 offset,
66 u64 size, char *out)
67 {
68 u64 physical, clen, dlen, orig_size = size;
69 u32 res;
70 char *cbuf, *dbuf;
71
72 clen = extent->disk_num_bytes;
73 dlen = extent->num_bytes;
74
75 if (offset > dlen)
76 return -1ULL;
77
78 if (size > dlen - offset)
79 size = dlen - offset;
80
81 physical = btrfs_map_logical_to_physical(extent->disk_bytenr);
82 if (physical == -1ULL)
83 return -1ULL;
84
85 if (extent->compression == BTRFS_COMPRESS_NONE) {
86 physical += extent->offset + offset;
87 if (!btrfs_devread(physical, size, out))
88 return -1ULL;
89
90 return size;
91 }
92
93 cbuf = malloc_cache_aligned(dlen > size ? clen + dlen : clen);
94 if (!cbuf)
95 return -1ULL;
96
97 if (dlen > orig_size)
98 dbuf = cbuf + clen;
99 else
100 dbuf = out;
101
102 if (!btrfs_devread(physical, clen, cbuf))
103 goto err;
104
105 res = btrfs_decompress(extent->compression, cbuf, clen, dbuf, dlen);
106 if (res == -1)
107 goto err;
108
109 if (dlen > orig_size)
110 memcpy(out, dbuf + offset, size);
111 else
112 memmove(out, dbuf + offset, size);
113
114 free(cbuf);
115 return res;
116
117 err:
118 free(cbuf);
119 return -1ULL;
120 }
121