aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--fs/squashfs/Kconfig13
-rw-r--r--fs/squashfs/Makefile9
-rw-r--r--fs/squashfs/decompressor_multi.c200
3 files changed, 221 insertions, 1 deletions
diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index c70111ebefd4..1c6d340fc61f 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -63,6 +63,19 @@ config SQUASHFS_LZO
63 63
64 If unsure, say N. 64 If unsure, say N.
65 65
66config SQUASHFS_MULTI_DECOMPRESSOR
67 bool "Use multiple decompressors for handling parallel I/O"
68 depends on SQUASHFS
69 help
70 By default Squashfs uses a single decompressor but it gives
71 poor performance on parallel I/O workloads when using multiple CPU
72 machines due to waiting on decompressor availability.
73
74 If you have a parallel I/O workload and your system has enough memory,
75 using this option may improve overall I/O performance.
76
77 If unsure, say N.
78
66config SQUASHFS_XZ 79config SQUASHFS_XZ
67 bool "Include support for XZ compressed file systems" 80 bool "Include support for XZ compressed file systems"
68 depends on SQUASHFS 81 depends on SQUASHFS
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index c223c8439c21..dfebc3b12d61 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -4,8 +4,15 @@
4 4
5obj-$(CONFIG_SQUASHFS) += squashfs.o 5obj-$(CONFIG_SQUASHFS) += squashfs.o
6squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o 6squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
7squashfs-y += namei.o super.o symlink.o decompressor.o decompressor_single.o 7squashfs-y += namei.o super.o symlink.o decompressor.o
8
8squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o 9squashfs-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
9squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o 10squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
10squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o 11squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
11squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o 12squashfs-$(CONFIG_SQUASHFS_ZLIB) += zlib_wrapper.o
13
14ifdef CONFIG_SQUASHFS_MULTI_DECOMPRESSOR
15 squashfs-y += decompressor_multi.o
16else
17 squashfs-y += decompressor_single.o
18endif
diff --git a/fs/squashfs/decompressor_multi.c b/fs/squashfs/decompressor_multi.c
new file mode 100644
index 000000000000..462731db5130
--- /dev/null
+++ b/fs/squashfs/decompressor_multi.c
@@ -0,0 +1,200 @@
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 }
123
124 WARN_ON(stream->avail_decomp);
125 kfree(stream->comp_opts);
126 kfree(stream);
127}
128
129
130static struct decomp_stream *get_decomp_stream(struct squashfs_sb_info *msblk,
131 struct squashfs_stream *stream)
132{
133 struct decomp_stream *decomp_strm;
134
135 while (1) {
136 mutex_lock(&stream->mutex);
137
138 /* There is available decomp_stream */
139 if (!list_empty(&stream->strm_list)) {
140 decomp_strm = list_entry(stream->strm_list.prev,
141 struct decomp_stream, list);
142 list_del(&decomp_strm->list);
143 mutex_unlock(&stream->mutex);
144 break;
145 }
146
147 /*
148 * If there is no available decomp and already full,
149 * let's wait for releasing decomp from other users.
150 */
151 if (stream->avail_decomp >= MAX_DECOMPRESSOR)
152 goto wait;
153
154 /* Let's allocate new decomp */
155 decomp_strm = kmalloc(sizeof(*decomp_strm), GFP_KERNEL);
156 if (!decomp_strm)
157 goto wait;
158
159 decomp_strm->stream = msblk->decompressor->init(msblk,
160 stream->comp_opts);
161 if (IS_ERR(decomp_strm->stream)) {
162 kfree(decomp_strm);
163 goto wait;
164 }
165
166 stream->avail_decomp++;
167 WARN_ON(stream->avail_decomp > MAX_DECOMPRESSOR);
168
169 mutex_unlock(&stream->mutex);
170 break;
171wait:
172 /*
173 * If system memory is tough, let's for other's
174 * releasing instead of hurting VM because it could
175 * make page cache thrashing.
176 */
177 mutex_unlock(&stream->mutex);
178 wait_event(stream->wait,
179 !list_empty(&stream->strm_list));
180 }
181
182 return decomp_strm;
183}
184
185
186int squashfs_decompress(struct squashfs_sb_info *msblk,
187 void **buffer, struct buffer_head **bh, int b, int offset, int length,
188 int srclength, int pages)
189{
190 int res;
191 struct squashfs_stream *stream = msblk->stream;
192 struct decomp_stream *decomp_stream = get_decomp_stream(msblk, stream);
193 res = msblk->decompressor->decompress(msblk, decomp_stream->stream,
194 buffer, bh, b, offset, length, srclength, pages);
195 put_decomp_stream(decomp_stream, stream);
196 if (res < 0)
197 ERROR("%s decompression failed, data probably corrupt\n",
198 msblk->decompressor->name);
199 return res;
200}
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-27 19:39:58 -0500