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1/*
2 * Copyright (c) 2013
3 * Minchan Kim <minchan@kernel.org>
4 *
5 * This work is licensed under the terms of the GNU GPL, version 2. See
6 * the COPYING file in the top-level directory.
7 */
8#include <linux/types.h>
9#include <linux/mutex.h>
10#include <linux/slab.h>
11#include <linux/buffer_head.h>
12#include <linux/sched.h>
13#include <linux/wait.h>
14#include <linux/cpumask.h>
15
16#include "squashfs_fs.h"
17#include "squashfs_fs_sb.h"
18#include "decompressor.h"
19#include "squashfs.h"
20
21/*
22 * This file implements multi-threaded decompression in the
23 * decompressor framework
24 */
25
26
27/*
28 * The reason that multiply two is that a CPU can request new I/O
29 * while it is waiting previous request.
30 */
31#define MAX_DECOMPRESSOR (num_online_cpus() * 2)
32
33
34int squashfs_max_decompressors(void)
35{
36 return MAX_DECOMPRESSOR;
37}
38
39
40struct squashfs_stream {
41 void *comp_opts;
42 struct list_head strm_list;
43 struct mutex mutex;
44 int avail_decomp;
45 wait_queue_head_t wait;
46};
47
48
49struct decomp_stream {
50 void *stream;
51 struct list_head list;
52};
53
54
55static void put_decomp_stream(struct decomp_stream *decomp_strm,
56 struct squashfs_stream *stream)
57{
58 mutex_lock(&stream->mutex);
59 list_add(&decomp_strm->list, &stream->strm_list);
60 mutex_unlock(&stream->mutex);
61 wake_up(&stream->wait);
62}
63
64void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
65 void *comp_opts)
66{
67 struct squashfs_stream *stream;
68 struct decomp_stream *decomp_strm = NULL;
69 int err = -ENOMEM;
70
71 stream = kzalloc(sizeof(*stream), GFP_KERNEL);
72 if (!stream)
73 goto out;
74
75 stream->comp_opts = comp_opts;
76 mutex_init(&stream->mutex);
77 INIT_LIST_HEAD(&stream->strm_list);
78 init_waitqueue_head(&stream->wait);
79
80 /*
81 * We should have a decompressor at least as default
82 * so if we fail to allocate new decompressor dynamically,
83 * we could always fall back to default decompressor and
84 * file system works.
85 */
86 decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
87 if (!decomp_strm)
88 goto out;
89
90 decomp_strm->stream = msblk->decompressor->init(msblk,
91 stream->comp_opts);
92 if (IS_ERR(decomp_strm->stream)) {
93 err = PTR_ERR(decomp_strm->stream);
94 goto out;
95 }
96
97 list_add(&decomp_strm->list, &stream->strm_list);
98 stream->avail_decomp = 1;
99 return stream;
100
101out:
102 kfree(decomp_strm);
103 kfree(stream);
104 return ERR_PTR(err);
105}
106
107
108void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
109{
110 struct squashfs_stream *stream = msblk->stream;
111 if (stream) {
112 struct decomp_stream *decomp_strm;
113
114 while (!list_empty(&stream->strm_list)) {
115 decomp_strm = list_entry(stream->strm_list.prev,
116 struct decomp_stream, list);
117 list_del(&decomp_strm->list);
118 msblk->decompressor->free(decomp_strm->stream);
119 kfree(decomp_strm);
120 stream->avail_decomp--;
121 }
122 WARN_ON(stream->avail_decomp);
123 kfree(stream->comp_opts);
124 kfree(stream);
125 }
126}
127
128
129static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk,
130 struct squashfs_stream *stream)
131{
132 struct decomp_stream *decomp_strm;
133
134 while (1) {
135 mutex_lock(&stream->mutex);
136
137 /* There is available decomp_stream */
138 if (!list_empty(&stream->strm_list)) {
139 decomp_strm = list_entry(stream->strm_list.prev,
140 struct decomp_stream, list);
141 list_del(&decomp_strm->list);
142 mutex_unlock(&stream->mutex);
143 break;
144 }
145
146 /*
147 * If there is no available decomp and already full,
148 * let's wait for releasing decomp from other users.
149 */
150 if (stream->avail_decomp >= MAX_DECOMPRESSOR)
151 goto wait;
152
153 /* Let's allocate new decomp */
154 decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
155 if (!decomp_strm)
156 goto wait;
157
158 decomp_strm->stream = msblk->decompressor->init(msblk,
159 stream->comp_opts);
160 if (IS_ERR(decomp_strm->stream)) {
161 kfree(decomp_strm);
162 goto wait;
163 }
164
165 stream->avail_decomp++;
166 WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR);
167
168 mutex_unlock(&stream->mutex);
169 break;
170wait:
171 /*
172 * If system memory is tough, let's for other's
173 * releasing instead of hurting VM because it could
174 * make page cache thrashing.
175 */
176 mutex_unlock(&stream->mutex);
177 wait_event(stream->wait,
178 !list_empty(&stream->strm_list));
179 }
180
181 return decomp_strm;
182}
183
184
185int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
186 int b, int offset, int length, struct squashfs_page_actor *output)
187{
188 int res;
189 struct squashfs_stream *stream = msblk->stream;
190 struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream);
191 res = msblk->decompressor->decompress(msblk, decomp_stream->stream,
192 bh, b, offset, length, output);
193 put_decomp_stream(decomp_stream, stream);
194 if (res < 0)
195 ERROR("%s decompression failed, data probably corrupt\n",
196 msblk->decompressor->name);
197 return res;
198}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2013
4 * Minchan Kim <minchan@kernel.org>
5 */
6#include <linux/types.h>
7#include <linux/mutex.h>
8#include <linux/slab.h>
9#include <linux/buffer_head.h>
10#include <linux/sched.h>
11#include <linux/wait.h>
12#include <linux/cpumask.h>
13
14#include "squashfs_fs.h"
15#include "squashfs_fs_sb.h"
16#include "decompressor.h"
17#include "squashfs.h"
18
19/*
20 * This file implements multi-threaded decompression in the
21 * decompressor framework
22 */
23
24
25/*
26 * The reason that multiply two is that a CPU can request new I/O
27 * while it is waiting previous request.
28 */
29#define MAX_DECOMPRESSOR (num_online_cpus() * 2)
30
31
32int squashfs_max_decompressors(void)
33{
34 return MAX_DECOMPRESSOR;
35}
36
37
38struct squashfs_stream {
39 void *comp_opts;
40 struct list_head strm_list;
41 struct mutex mutex;
42 int avail_decomp;
43 wait_queue_head_t wait;
44};
45
46
47struct decomp_stream {
48 void *stream;
49 struct list_head list;
50};
51
52
53static void put_decomp_stream(struct decomp_stream *decomp_strm,
54 struct squashfs_stream *stream)
55{
56 mutex_lock(&stream->mutex);
57 list_add(&decomp_strm->list, &stream->strm_list);
58 mutex_unlock(&stream->mutex);
59 wake_up(&stream->wait);
60}
61
62void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
63 void *comp_opts)
64{
65 struct squashfs_stream *stream;
66 struct decomp_stream *decomp_strm = NULL;
67 int err = -ENOMEM;
68
69 stream = kzalloc(sizeof(*stream), GFP_KERNEL);
70 if (!stream)
71 goto out;
72
73 stream->comp_opts = comp_opts;
74 mutex_init(&stream->mutex);
75 INIT_LIST_HEAD(&stream->strm_list);
76 init_waitqueue_head(&stream->wait);
77
78 /*
79 * We should have a decompressor at least as default
80 * so if we fail to allocate new decompressor dynamically,
81 * we could always fall back to default decompressor and
82 * file system works.
83 */
84 decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
85 if (!decomp_strm)
86 goto out;
87
88 decomp_strm->stream = msblk->decompressor->init(msblk,
89 stream->comp_opts);
90 if (IS_ERR(decomp_strm->stream)) {
91 err = PTR_ERR(decomp_strm->stream);
92 goto out;
93 }
94
95 list_add(&decomp_strm->list, &stream->strm_list);
96 stream->avail_decomp = 1;
97 return stream;
98
99out:
100 kfree(decomp_strm);
101 kfree(stream);
102 return ERR_PTR(err);
103}
104
105
106void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
107{
108 struct squashfs_stream *stream = msblk->stream;
109 if (stream) {
110 struct decomp_stream *decomp_strm;
111
112 while (!list_empty(&stream->strm_list)) {
113 decomp_strm = list_entry(stream->strm_list.prev,
114 struct decomp_stream, list);
115 list_del(&decomp_strm->list);
116 msblk->decompressor->free(decomp_strm->stream);
117 kfree(decomp_strm);
118 stream->avail_decomp--;
119 }
120 WARN_ON(stream->avail_decomp);
121 kfree(stream->comp_opts);
122 kfree(stream);
123 }
124}
125
126
127static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk,
128 struct squashfs_stream *stream)
129{
130 struct decomp_stream *decomp_strm;
131
132 while (1) {
133 mutex_lock(&stream->mutex);
134
135 /* There is available decomp_stream */
136 if (!list_empty(&stream->strm_list)) {
137 decomp_strm = list_entry(stream->strm_list.prev,
138 struct decomp_stream, list);
139 list_del(&decomp_strm->list);
140 mutex_unlock(&stream->mutex);
141 break;
142 }
143
144 /*
145 * If there is no available decomp and already full,
146 * let's wait for releasing decomp from other users.
147 */
148 if (stream->avail_decomp >= MAX_DECOMPRESSOR)
149 goto wait;
150
151 /* Let's allocate new decomp */
152 decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
153 if (!decomp_strm)
154 goto wait;
155
156 decomp_strm->stream = msblk->decompressor->init(msblk,
157 stream->comp_opts);
158 if (IS_ERR(decomp_strm->stream)) {
159 kfree(decomp_strm);
160 goto wait;
161 }
162
163 stream->avail_decomp++;
164 WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR);
165
166 mutex_unlock(&stream->mutex);
167 break;
168wait:
169 /*
170 * If system memory is tough, let's for other's
171 * releasing instead of hurting VM because it could
172 * make page cache thrashing.
173 */
174 mutex_unlock(&stream->mutex);
175 wait_event(stream->wait,
176 !list_empty(&stream->strm_list));
177 }
178
179 return decomp_strm;
180}
181
182
183int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
184 int b, int offset, int length, struct squashfs_page_actor *output)
185{
186 int res;
187 struct squashfs_stream *stream = msblk->stream;
188 struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream);
189 res = msblk->decompressor->decompress(msblk, decomp_stream->stream,
190 bh, b, offset, length, output);
191 put_decomp_stream(decomp_stream, stream);
192 if (res < 0)
193 ERROR("%s decompression failed, data probably corrupt\n",
194 msblk->decompressor->name);
195 return res;
196}