[PATCH v3] erofs: support deflate decompress by using Intel QAT

Bo Liu liubo03 at inspur.com
Fri May 16 18:26:34 AEST 2025


This patch introdueces the use of the Intel QAT to decompress compressed
data in the EROFS filesystem, aiming to improve the decompression speed
of compressed datea.

We created a 285MiB compressed file and then used the following command to
create EROFS images with different cluster size.
     # mkfs.erofs -zdeflate,level=9 -C16384

fio command was used to test random read and small random read(~5%) and
sequential read performance.
     # fio -filename=testfile  -bs=4k -rw=read -name=job1
     # fio -filename=testfile  -bs=4k -rw=randread -name=job1
     # fio -filename=testfile  -bs=4k -rw=randread --io_size=14m -name=job1

Here are some performance numbers for reference:

Processors: Intel(R) Xeon(R) 6766E(144 core)
Memory:     521 GiB

|-----------------------------------------------------------------------------|
|           | Cluster size | sequential read | randread  | small randread(5%) |
|-----------|--------------|-----------------|-----------|--------------------|
| Intel QAT |    4096      |    538  MiB/s   | 112 MiB/s |     20.76 MiB/s    |
| Intel QAT |    16384     |    699  MiB/s   | 158 MiB/s |     21.02 MiB/s    |
| Intel QAT |    65536     |    917  MiB/s   | 278 MiB/s |     20.90 MiB/s    |
| Intel QAT |    131072    |    1056 MiB/s   | 351 MiB/s |     23.36 MiB/s    |
| Intel QAT |    262144    |    1145 MiB/s   | 431 MiB/s |     26.66 MiB/s    |
| deflate   |    4096      |    499  MiB/s   | 108 MiB/s |     21.50 MiB/s    |
| deflate   |    16384     |    422  MiB/s   | 125 MiB/s |     18.94 MiB/s    |
| deflate   |    65536     |    452  MiB/s   | 159 MiB/s |     13.02 MiB/s    |
| deflate   |    131072    |    452  MiB/s   | 177 MiB/s |     11.44 MiB/s    |
| deflate   |    262144    |    466  MiB/s   | 194 MiB/s |     10.60 MiB/s    |

Signed-off-by: Bo Liu <liubo03 at inspur.com>
---
v1: https://lore.kernel.org/linux-erofs/20250410042048.3044-1-liubo03@inspur.com/
v2: https://lore.kernel.org/linux-erofs/20250410042048.3044-1-liubo03@inspur.com/T/#t

Changes since v2:
 - Add a new kernel config option CONFIG_EROFS_FS_ZIP_CRYPTO. 
 - Modify the sysfs interface to merge enable and disable into
   a single entry point, and add a read function to view the current state.
 - Optimize the relevant code,use the sg_alloc_table_from_pages_segment interface.

 fs/erofs/Kconfig                |  14 +++
 fs/erofs/Makefile               |   1 +
 fs/erofs/compress.h             |  14 +++
 fs/erofs/decompressor_crypto.c  | 199 ++++++++++++++++++++++++++++++++
 fs/erofs/decompressor_deflate.c |  16 ++-
 fs/erofs/sysfs.c                |  36 ++++++
 6 files changed, 279 insertions(+), 1 deletion(-)
 create mode 100644 fs/erofs/decompressor_crypto.c

diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 331e49cd1b8d..db49ae3c1922 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -144,6 +144,20 @@ config EROFS_FS_ZIP_ZSTD
 
 	  If unsure, say N.
 
+config EROFS_FS_ZIP_CRYPTO
+	bool "EROFS hardware decompression support (crypto interface)"
+	depends on EROFS_FS_ZIP
+	help
+	  Saying Y here includes support for reading EROFS file systems
+	  containing crypto compressed data.  It gives better decompression
+	  speed than the software-implemented compression, and it costs
+	  lower CPU overhead.
+
+	  Crypto support is an experimental feature for now and so most
+	  file systems will be readable without selecting this option.
+
+	  If unsure, say N.
+
 config EROFS_FS_ONDEMAND
 	bool "EROFS fscache-based on-demand read support (deprecated)"
 	depends on EROFS_FS
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index 4331d53c7109..247b263eb667 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -7,5 +7,6 @@ erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o zdata.o zutil.o
 erofs-$(CONFIG_EROFS_FS_ZIP_LZMA) += decompressor_lzma.o
 erofs-$(CONFIG_EROFS_FS_ZIP_DEFLATE) += decompressor_deflate.o
 erofs-$(CONFIG_EROFS_FS_ZIP_ZSTD) += decompressor_zstd.o
+erofs-$(CONFIG_EROFS_FS_ZIP_CRYPTO) += decompressor_crypto.o
 erofs-$(CONFIG_EROFS_FS_BACKED_BY_FILE) += fileio.o
 erofs-$(CONFIG_EROFS_FS_ONDEMAND) += fscache.o
diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
index 2704d7a592a5..356ae2473bd5 100644
--- a/fs/erofs/compress.h
+++ b/fs/erofs/compress.h
@@ -70,10 +70,24 @@ struct z_erofs_stream_dctx {
 	bool bounced;			/* is the bounce buffer used now? */
 };
 
+struct z_erofs_crypto_engine {
+	char *crypto_name;
+	bool enabled;
+	struct crypto_acomp *erofs_tfm;
+};
+
+extern struct z_erofs_crypto_engine z_erofs_crypto[Z_EROFS_COMPRESSION_MAX][2];
+
 int z_erofs_stream_switch_bufs(struct z_erofs_stream_dctx *dctx, void **dst,
 			       void **src, struct page **pgpl);
 int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf,
 			 unsigned int padbufsize);
 int __init z_erofs_init_decompressor(void);
 void z_erofs_exit_decompressor(void);
+int z_erofs_crypto_decompress(struct z_erofs_decompress_req *rq,
+						struct crypto_acomp *erofs_tfm, struct page **pgpl);
+struct crypto_acomp *z_erofs_crypto_get_engine(int type);
+int z_erofs_crypto_enable_engine(const char *name);
+void z_erofs_crypto_disable_engine(void);
+int z_erofs_crypto_engine_format(char *buf);
 #endif
diff --git a/fs/erofs/decompressor_crypto.c b/fs/erofs/decompressor_crypto.c
new file mode 100644
index 000000000000..55f6a9e6dcf6
--- /dev/null
+++ b/fs/erofs/decompressor_crypto.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/scatterlist.h>
+#include <crypto/acompress.h>
+
+#include "compress.h"
+
+static int z_erofs_crypto_decompress_mem(struct z_erofs_decompress_req *rq,
+				struct crypto_acomp *erofs_tfm)
+{
+	struct sg_table st_src, st_dst;
+	struct acomp_req *req;
+	struct crypto_wait wait;
+	u8 *headpage;
+	int ret;
+
+	headpage = kmap_local_page(*rq->in);
+	ret = z_erofs_fixup_insize(rq, headpage + rq->pageofs_in,
+				min_t(unsigned int, rq->inputsize,
+							rq->sb->s_blocksize - rq->pageofs_in));
+	kunmap_local(headpage);
+	if (ret)
+		return ret;
+
+	req = acomp_request_alloc(erofs_tfm);
+	if (!req) {
+		erofs_err(rq->sb, "failed to alloc decompress request");
+		return -ENOMEM;
+	}
+
+	ret = sg_alloc_table_from_pages_segment(&st_src,
+					rq->in, rq->inpages, rq->pageofs_in,
+					rq->inputsize, UINT_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto failed_src_alloc;
+
+	ret = sg_alloc_table_from_pages_segment(&st_dst,
+					rq->out, rq->outpages, rq->pageofs_out,
+					rq->outputsize, UINT_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto failed_dst_alloc;
+
+	acomp_request_set_params(req, st_src.sgl,
+		st_dst.sgl, rq->inputsize, rq->outputsize);
+
+	crypto_init_wait(&wait);
+	acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+				crypto_req_done, &wait);
+
+	ret = crypto_wait_req(crypto_acomp_decompress(req), &wait);
+	if (ret < 0) {
+		erofs_err(rq->sb, "failed to decompress %d in[%u, %u] out[%u]",
+					ret, rq->inputsize, rq->pageofs_in, rq->outputsize);
+		ret = -EIO;
+	} else
+		ret = 0;
+
+	sg_free_table(&st_dst);
+failed_dst_alloc:
+	sg_free_table(&st_src);
+failed_src_alloc:
+	acomp_request_free(req);
+	return ret;
+}
+
+int z_erofs_crypto_decompress(struct z_erofs_decompress_req *rq,
+				struct crypto_acomp *erofs_tfm, struct page **pgpl)
+{
+	int i;
+
+	for (i = 0; i < rq->outpages; i++) {
+		struct page *const page = rq->out[i];
+		struct page *victim;
+
+		if (!page) {
+			victim = __erofs_allocpage(pgpl, rq->gfp, true);
+			if (!victim)
+				return -ENOMEM;
+			set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE);
+			rq->out[i] = victim;
+		}
+	}
+
+	return z_erofs_crypto_decompress_mem(rq, erofs_tfm);
+}
+
+struct crypto_acomp *z_erofs_crypto_get_engine(int type)
+{
+	int i = 0;
+
+	while (z_erofs_crypto[type][i].crypto_name) {
+		if (z_erofs_crypto[type][i].enabled)
+			return z_erofs_crypto[type][i].erofs_tfm;
+		i++;
+	}
+	return NULL;
+}
+
+static int z_erofs_crypto_get_compress_type(const char *name)
+{
+	int i, j;
+
+	for (i = 0; i < Z_EROFS_COMPRESSION_MAX; i++) {
+		j = 0;
+		while (z_erofs_crypto[i][j].crypto_name) {
+			if (!strcmp(name, z_erofs_crypto[i][j].crypto_name))
+				return i;
+
+			j++;
+		}
+	}
+	return -EINVAL;
+}
+
+int z_erofs_crypto_enable_engine(const char *name)
+{
+	int i = 0, type;
+
+	type = z_erofs_crypto_get_compress_type(name);
+	if (type < 0)
+		return -EINVAL;
+
+	while (z_erofs_crypto[type][i].crypto_name) {
+		if (!strcmp(z_erofs_crypto[type][i].crypto_name, name)) {
+			if (z_erofs_crypto[type][i].enabled)
+				break;
+
+			z_erofs_crypto[type][i].erofs_tfm =
+				crypto_alloc_acomp(z_erofs_crypto[type][i].crypto_name, 0, 0);
+			if (IS_ERR(z_erofs_crypto[type][i].erofs_tfm)) {
+				z_erofs_crypto[type][i].erofs_tfm = NULL;
+				return -ENXIO;
+			}
+			z_erofs_crypto[type][i].enabled = true;
+		} else if (z_erofs_crypto[type][i].enabled) {
+			if (z_erofs_crypto[type][i].erofs_tfm)
+				crypto_free_acomp(z_erofs_crypto[type][i].erofs_tfm);
+			z_erofs_crypto[type][i].enabled = false;
+		}
+		i++;
+	}
+	return 0;
+}
+
+void z_erofs_crypto_disable_engine(void)
+{
+	int i = 0, type;
+
+	for (type = 0; type < Z_EROFS_COMPRESSION_MAX; type++) {
+		i = 0;
+		while (z_erofs_crypto[type][i].crypto_name) {
+			if (z_erofs_crypto[type][i].enabled &&
+					z_erofs_crypto[type][i].erofs_tfm) {
+				crypto_free_acomp(z_erofs_crypto[type][i].erofs_tfm);
+				z_erofs_crypto[type][i].erofs_tfm = NULL;
+				z_erofs_crypto[type][i].enabled = false;
+			}
+			i++;
+		}
+	}
+}
+
+int z_erofs_crypto_engine_format(char *buf)
+{
+	int type, i, len = 0;
+
+	for (type = 0; type < Z_EROFS_COMPRESSION_MAX; type++) {
+		i = 0;
+		while (z_erofs_crypto[type][i].crypto_name) {
+			if (z_erofs_crypto[type][i].enabled)
+				len += scnprintf(buf + len, PATH_MAX - len, "%s ",
+							z_erofs_crypto[type][i].crypto_name);
+			i++;
+		}
+	}
+	return len;
+}
+
+struct z_erofs_crypto_engine z_erofs_crypto[Z_EROFS_COMPRESSION_MAX][2] = {
+	[Z_EROFS_COMPRESSION_LZ4] = {
+		(struct z_erofs_crypto_engine) {NULL},
+		(struct z_erofs_crypto_engine) {NULL},
+	},
+	[Z_EROFS_COMPRESSION_LZMA] = {
+		(struct z_erofs_crypto_engine) {NULL},
+		(struct z_erofs_crypto_engine) {NULL},
+	},
+	[Z_EROFS_COMPRESSION_DEFLATE] = {
+		(struct z_erofs_crypto_engine) {
+			.crypto_name = "qat_deflate",
+			.enabled = false,
+			.erofs_tfm = NULL,
+		},
+		(struct z_erofs_crypto_engine) {NULL},
+	},
+	[Z_EROFS_COMPRESSION_ZSTD] = {
+		(struct z_erofs_crypto_engine) {NULL},
+		(struct z_erofs_crypto_engine) {NULL},
+	},
+};
diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflate.c
index c6908a487054..bebbf1eccd3d 100644
--- a/fs/erofs/decompressor_deflate.c
+++ b/fs/erofs/decompressor_deflate.c
@@ -97,7 +97,7 @@ static int z_erofs_load_deflate_config(struct super_block *sb,
 	return -ENOMEM;
 }
 
-static int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
+static int __z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
 				      struct page **pgpl)
 {
 	struct super_block *sb = rq->sb;
@@ -178,6 +178,20 @@ static int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
 	return err;
 }
 
+static int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,
+				struct page **pgpl)
+{
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+	struct crypto_acomp *erofs_tfm = NULL;
+
+	erofs_tfm = z_erofs_crypto_get_engine(Z_EROFS_COMPRESSION_DEFLATE);
+	if (erofs_tfm && !rq->partial_decoding)
+		return z_erofs_crypto_decompress(rq, erofs_tfm, pgpl);
+	else
+#endif
+		return __z_erofs_deflate_decompress(rq, pgpl);
+}
+
 const struct z_erofs_decompressor z_erofs_deflate_decomp = {
 	.config = z_erofs_load_deflate_config,
 	.decompress = z_erofs_deflate_decompress,
diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index dad4e6c6c155..00123c4d3196 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -7,12 +7,14 @@
 #include <linux/kobject.h>
 
 #include "internal.h"
+#include "compress.h"
 
 enum {
 	attr_feature,
 	attr_drop_caches,
 	attr_pointer_ui,
 	attr_pointer_bool,
+	attr_crypto,
 };
 
 enum {
@@ -60,6 +62,9 @@ static struct erofs_attr erofs_attr_##_name = {			\
 EROFS_ATTR_RW_UI(sync_decompress, erofs_mount_opts);
 EROFS_ATTR_FUNC(drop_caches, 0200);
 #endif
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+EROFS_ATTR_FUNC(crypto, 0644);
+#endif
 
 static struct attribute *erofs_attrs[] = {
 #ifdef CONFIG_EROFS_FS_ZIP
@@ -95,6 +100,9 @@ static struct attribute *erofs_feat_attrs[] = {
 	ATTR_LIST(fragments),
 	ATTR_LIST(dedupe),
 	ATTR_LIST(48bit),
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+	ATTR_LIST(crypto),
+#endif
 	NULL,
 };
 ATTRIBUTE_GROUPS(erofs_feat);
@@ -128,6 +136,10 @@ static ssize_t erofs_attr_show(struct kobject *kobj,
 		if (!ptr)
 			return 0;
 		return sysfs_emit(buf, "%d\n", *(bool *)ptr);
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+	case attr_crypto:
+		return z_erofs_crypto_engine_format(buf);
+#endif
 	}
 	return 0;
 }
@@ -141,6 +153,10 @@ static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
 	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
 	unsigned long t;
 	int ret;
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+	char *crypto_name;
+	size_t sz;
+#endif
 
 	switch (a->attr_id) {
 	case attr_pointer_ui:
@@ -181,6 +197,26 @@ static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
 		if (t & 1)
 			invalidate_mapping_pages(MNGD_MAPPING(sbi), 0, -1);
 		return len;
+#endif
+#ifdef CONFIG_EROFS_FS_ZIP_CRYPTO
+	case attr_crypto:
+		buf = skip_spaces(buf);
+		sz = strlen(buf);
+		crypto_name = kstrdup(buf, GFP_KERNEL);
+		if (!crypto_name)
+			return -ENOMEM;
+
+		/* ignore trailing newline */
+		if (sz > 0 && crypto_name[sz - 1] == '\n')
+			crypto_name[sz - 1] = 0x00;
+
+		if (strlen(crypto_name) > 0) {
+			ret = z_erofs_crypto_enable_engine(crypto_name);
+			if (ret < 0)
+				return ret;
+		} else
+			z_erofs_crypto_disable_engine();
+		return len;
 #endif
 	}
 	return 0;
-- 
2.31.1



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