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Commit | Line | Data |
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3e0a4e85 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
87bf54bb SP |
2 | /* |
3 | * Squashfs - a compressed read only filesystem for Linux | |
4 | * | |
5 | * Copyright (c) 2016-present, Facebook, Inc. | |
6 | * All rights reserved. | |
7 | * | |
87bf54bb SP |
8 | * zstd_wrapper.c |
9 | */ | |
10 | ||
11 | #include <linux/mutex.h> | |
93e72b3c | 12 | #include <linux/bio.h> |
87bf54bb SP |
13 | #include <linux/slab.h> |
14 | #include <linux/zstd.h> | |
15 | #include <linux/vmalloc.h> | |
16 | ||
17 | #include "squashfs_fs.h" | |
18 | #include "squashfs_fs_sb.h" | |
19 | #include "squashfs.h" | |
20 | #include "decompressor.h" | |
21 | #include "page_actor.h" | |
22 | ||
23 | struct workspace { | |
24 | void *mem; | |
25 | size_t mem_size; | |
26 | size_t window_size; | |
27 | }; | |
28 | ||
29 | static void *zstd_init(struct squashfs_sb_info *msblk, void *buff) | |
30 | { | |
31 | struct workspace *wksp = kmalloc(sizeof(*wksp), GFP_KERNEL); | |
32 | ||
33 | if (wksp == NULL) | |
34 | goto failed; | |
35 | wksp->window_size = max_t(size_t, | |
36 | msblk->block_size, SQUASHFS_METADATA_SIZE); | |
37 | wksp->mem_size = ZSTD_DStreamWorkspaceBound(wksp->window_size); | |
38 | wksp->mem = vmalloc(wksp->mem_size); | |
39 | if (wksp->mem == NULL) | |
40 | goto failed; | |
41 | ||
42 | return wksp; | |
43 | ||
44 | failed: | |
45 | ERROR("Failed to allocate zstd workspace\n"); | |
46 | kfree(wksp); | |
47 | return ERR_PTR(-ENOMEM); | |
48 | } | |
49 | ||
50 | ||
51 | static void zstd_free(void *strm) | |
52 | { | |
53 | struct workspace *wksp = strm; | |
54 | ||
55 | if (wksp) | |
56 | vfree(wksp->mem); | |
57 | kfree(wksp); | |
58 | } | |
59 | ||
60 | ||
61 | static int zstd_uncompress(struct squashfs_sb_info *msblk, void *strm, | |
93e72b3c | 62 | struct bio *bio, int offset, int length, |
87bf54bb SP |
63 | struct squashfs_page_actor *output) |
64 | { | |
65 | struct workspace *wksp = strm; | |
66 | ZSTD_DStream *stream; | |
67 | size_t total_out = 0; | |
93e72b3c | 68 | int error = 0; |
87bf54bb SP |
69 | ZSTD_inBuffer in_buf = { NULL, 0, 0 }; |
70 | ZSTD_outBuffer out_buf = { NULL, 0, 0 }; | |
93e72b3c PL |
71 | struct bvec_iter_all iter_all = {}; |
72 | struct bio_vec *bvec = bvec_init_iter_all(&iter_all); | |
87bf54bb SP |
73 | |
74 | stream = ZSTD_initDStream(wksp->window_size, wksp->mem, wksp->mem_size); | |
75 | ||
76 | if (!stream) { | |
77 | ERROR("Failed to initialize zstd decompressor\n"); | |
93e72b3c | 78 | return -EIO; |
87bf54bb SP |
79 | } |
80 | ||
81 | out_buf.size = PAGE_SIZE; | |
82 | out_buf.dst = squashfs_first_page(output); | |
83 | ||
93e72b3c PL |
84 | for (;;) { |
85 | size_t zstd_err; | |
87bf54bb | 86 | |
93e72b3c PL |
87 | if (in_buf.pos == in_buf.size) { |
88 | const void *data; | |
89 | int avail; | |
90 | ||
91 | if (!bio_next_segment(bio, &iter_all)) { | |
92 | error = -EIO; | |
93 | break; | |
94 | } | |
95 | ||
96 | avail = min(length, ((int)bvec->bv_len) - offset); | |
fbc27241 | 97 | data = bvec_virt(bvec); |
87bf54bb | 98 | length -= avail; |
93e72b3c | 99 | in_buf.src = data + offset; |
87bf54bb SP |
100 | in_buf.size = avail; |
101 | in_buf.pos = 0; | |
102 | offset = 0; | |
103 | } | |
104 | ||
105 | if (out_buf.pos == out_buf.size) { | |
106 | out_buf.dst = squashfs_next_page(output); | |
107 | if (out_buf.dst == NULL) { | |
108 | /* Shouldn't run out of pages | |
109 | * before stream is done. | |
110 | */ | |
93e72b3c PL |
111 | error = -EIO; |
112 | break; | |
87bf54bb SP |
113 | } |
114 | out_buf.pos = 0; | |
115 | out_buf.size = PAGE_SIZE; | |
116 | } | |
117 | ||
118 | total_out -= out_buf.pos; | |
119 | zstd_err = ZSTD_decompressStream(stream, &out_buf, &in_buf); | |
120 | total_out += out_buf.pos; /* add the additional data produced */ | |
93e72b3c PL |
121 | if (zstd_err == 0) |
122 | break; | |
123 | ||
124 | if (ZSTD_isError(zstd_err)) { | |
125 | ERROR("zstd decompression error: %d\n", | |
126 | (int)ZSTD_getErrorCode(zstd_err)); | |
127 | error = -EIO; | |
128 | break; | |
129 | } | |
87bf54bb SP |
130 | } |
131 | ||
93e72b3c | 132 | squashfs_finish_page(output); |
87bf54bb | 133 | |
93e72b3c | 134 | return error ? error : total_out; |
87bf54bb SP |
135 | } |
136 | ||
137 | const struct squashfs_decompressor squashfs_zstd_comp_ops = { | |
138 | .init = zstd_init, | |
139 | .free = zstd_free, | |
140 | .decompress = zstd_uncompress, | |
141 | .id = ZSTD_COMPRESSION, | |
142 | .name = "zstd", | |
143 | .supported = 1 | |
144 | }; |