[v3,2/2] btrfs: Add zstd support to grub btrfs
diff mbox series

Message ID 20181009232137.1941290-3-terrelln@fb.com
State New
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Series
  • btrfs: Add zstd support to grub btrfs
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Commit Message

Nick Terrell Oct. 9, 2018, 11:21 p.m. UTC
Adds zstd support to the btrfs module.

Tested on Ubuntu-18.04 with a btrfs /boot partition with and without zstd
compression. A test case was also added to the test suite that fails before
the patch, and passes after.

Signed-off-by: Nick Terrell <terrelln@fb.com>
---
v1 -> v2:
- Fix comments from Daniel Kiper.

v2 -> v3:
- Use grub_error() to set grub_errno in grub_btrfs_zstd_decompress().
- Fix style and formatting comments.

 Makefile.util.def            |  10 +++-
 grub-core/Makefile.core.def  |  10 +++-
 grub-core/fs/btrfs.c         | 112 ++++++++++++++++++++++++++++++++++-
 tests/btrfs_test.in          |   1 +
 tests/util/grub-fs-tester.in |   2 +-
 5 files changed, 131 insertions(+), 4 deletions(-)

--
2.17.1

Comments

Daniel Kiper Oct. 11, 2018, 5:55 p.m. UTC | #1
On Tue, Oct 09, 2018 at 04:21:37PM -0700, Nick Terrell wrote:
> Adds zstd support to the btrfs module.
>
> Tested on Ubuntu-18.04 with a btrfs /boot partition with and without zstd
> compression. A test case was also added to the test suite that fails before
> the patch, and passes after.
>
> Signed-off-by: Nick Terrell <terrelln@fb.com>
> ---
> v1 -> v2:
> - Fix comments from Daniel Kiper.
>
> v2 -> v3:
> - Use grub_error() to set grub_errno in grub_btrfs_zstd_decompress().
> - Fix style and formatting comments.
>
>  Makefile.util.def            |  10 +++-
>  grub-core/Makefile.core.def  |  10 +++-
>  grub-core/fs/btrfs.c         | 112 ++++++++++++++++++++++++++++++++++-
>  tests/btrfs_test.in          |   1 +
>  tests/util/grub-fs-tester.in |   2 +-
>  5 files changed, 131 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile.util.def b/Makefile.util.def
> index f9caccb97..27c5e9903 100644
> --- a/Makefile.util.def
> +++ b/Makefile.util.def
> @@ -54,7 +54,7 @@ library = {
>  library = {
>    name = libgrubmods.a;
>    cflags = '-fno-builtin -Wno-undef';
> -  cppflags = '-I$(top_srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -DMINILZO_HAVE_CONFIG_H';
> +  cppflags = '-I$(srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -I$(srcdir)/grub-core/lib/zstd -DMINILZO_HAVE_CONFIG_H';
>
>    common_nodist = grub_script.tab.c;
>    common_nodist = grub_script.yy.c;
> @@ -164,6 +164,14 @@ library = {
>    common = grub-core/lib/xzembed/xz_dec_bcj.c;
>    common = grub-core/lib/xzembed/xz_dec_lzma2.c;
>    common = grub-core/lib/xzembed/xz_dec_stream.c;
> +  common = grub-core/lib/zstd/debug.c;
> +  common = grub-core/lib/zstd/entropy_common.c;
> +  common = grub-core/lib/zstd/error_private.c;
> +  common = grub-core/lib/zstd/fse_decompress.c;
> +  common = grub-core/lib/zstd/huf_decompress.c;
> +  common = grub-core/lib/zstd/xxhash.c;
> +  common = grub-core/lib/zstd/zstd_common.c;
> +  common = grub-core/lib/zstd/zstd_decompress.c;
>  };
>
>  program = {
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 2c1d62cee..f818f58bc 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -1265,8 +1265,16 @@ module = {
>    name = btrfs;
>    common = fs/btrfs.c;
>    common = lib/crc.c;
> +  common = lib/zstd/debug.c;
> +  common = lib/zstd/entropy_common.c;
> +  common = lib/zstd/error_private.c;
> +  common = lib/zstd/fse_decompress.c;
> +  common = lib/zstd/huf_decompress.c;
> +  common = lib/zstd/xxhash.c;
> +  common = lib/zstd/zstd_common.c;
> +  common = lib/zstd/zstd_decompress.c;
>    cflags = '$(CFLAGS_POSIX) -Wno-undef';
> -  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -DMINILZO_HAVE_CONFIG_H';
> +  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -I$(srcdir)/lib/zstd -DMINILZO_HAVE_CONFIG_H';
>  };

Please do not embed zstd lib into btrfs module here.
I would like to see zstd lib as separate module if possible.

>  module = {
> diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
> index 4849c1ceb..c44fe8029 100644
> --- a/grub-core/fs/btrfs.c
> +++ b/grub-core/fs/btrfs.c
> @@ -17,6 +17,8 @@
>   *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>   */
>
> +#define ZSTD_STATIC_LINKING_ONLY
> +
>  #include <grub/err.h>
>  #include <grub/file.h>
>  #include <grub/mm.h>
> @@ -27,6 +29,7 @@
>  #include <grub/lib/crc.h>
>  #include <grub/deflate.h>
>  #include <minilzo.h>
> +#include <zstd.h>
>  #include <grub/i18n.h>
>  #include <grub/btrfs.h>
>
> @@ -45,6 +48,9 @@ GRUB_MOD_LICENSE ("GPLv3+");
>  #define GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE (GRUB_BTRFS_LZO_BLOCK_SIZE + \
>  				     (GRUB_BTRFS_LZO_BLOCK_SIZE / 16) + 64 + 3)
>
> +#define ZSTD_BTRFS_MAX_WINDOWLOG 17
> +#define ZSTD_BTRFS_MAX_INPUT     (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
> +
>  typedef grub_uint8_t grub_btrfs_checksum_t[0x20];
>  typedef grub_uint16_t grub_btrfs_uuid_t[8];
>
> @@ -212,6 +218,7 @@ struct grub_btrfs_extent_data
>  #define GRUB_BTRFS_COMPRESSION_NONE 0
>  #define GRUB_BTRFS_COMPRESSION_ZLIB 1
>  #define GRUB_BTRFS_COMPRESSION_LZO  2
> +#define GRUB_BTRFS_COMPRESSION_ZSTD 3
>
>  #define GRUB_BTRFS_OBJECT_ID_CHUNK 0x100
>
> @@ -912,6 +919,95 @@ grub_btrfs_read_inode (struct grub_btrfs_data *data,
>    return grub_btrfs_read_logical (data, elemaddr, inode, sizeof (*inode), 0);
>  }
>
> +static void* grub_zstd_malloc (void* state, size_t size)
> +{
> +	(void)state;

Please drop this and use "__attribute__ ((unused))" in function prototype.

> +	return grub_malloc (size);
> +}
> +
> +static void grub_zstd_free (void* state, void* address)
> +{
> +	(void)state;

Ditto.

> +	return grub_free (address);
> +}
> +
> +static ZSTD_customMem grub_zstd_allocator (void)
> +{
> +	ZSTD_customMem allocator;
> +
> +	allocator.customAlloc = &grub_zstd_malloc;
> +	allocator.customFree = &grub_zstd_free;
> +	allocator.opaque = NULL;
> +
> +	return allocator;
> +}
> +
> +static grub_ssize_t
> +grub_btrfs_zstd_decompress (char *ibuf, grub_size_t isize, grub_off_t off,
> +			    char *obuf, grub_size_t osize)
> +{
> +	void *allocated = NULL;
> +	char *otmpbuf = obuf;
> +	grub_size_t otmpsize = osize;
> +	ZSTD_DCtx *dctx = NULL;
> +	grub_size_t zstd_ret;
> +	grub_ssize_t ret = -1;
> +
> +	/*
> +	 * Zstd will fail if it can't fit the entire output in the destination
> +	 * buffer, so if osize isn't large enough, allocate a temporary buffer.
> +	 */
> +	if (otmpsize < ZSTD_BTRFS_MAX_INPUT) {
> +		allocated = grub_malloc (ZSTD_BTRFS_MAX_INPUT);
> +		if (!allocated) {

Hmmm... Should not we say something here? Like grub_error() call below?
It seems to me that failing silently is bad idea here.

> +			goto err;
> +		}
> +		otmpbuf = (char*)allocated;
> +		otmpsize = ZSTD_BTRFS_MAX_INPUT;
> +	}
> +
> +	/* Create the ZSTD_DCtx. */
> +	dctx = ZSTD_createDCtx_advanced (grub_zstd_allocator ());
> +	if (!dctx) {
> +		grub_error (GRUB_ERR_OUT_OF_MEMORY, "zstd out of memory");
> +		goto err;
> +	}

Daniel
Nick Terrell Oct. 11, 2018, 6:02 p.m. UTC | #2
> On Oct 11, 2018, at 10:55 AM, Daniel Kiper <dkiper@net-space.pl> wrote:
> 
> On Tue, Oct 09, 2018 at 04:21:37PM -0700, Nick Terrell wrote:
>> Adds zstd support to the btrfs module.
>> 
>> Tested on Ubuntu-18.04 with a btrfs /boot partition with and without zstd
>> compression. A test case was also added to the test suite that fails before
>> the patch, and passes after.
>> 
>> Signed-off-by: Nick Terrell <terrelln@fb.com>
>> ---
>> v1 -> v2:
>> - Fix comments from Daniel Kiper.
>> 
>> v2 -> v3:
>> - Use grub_error() to set grub_errno in grub_btrfs_zstd_decompress().
>> - Fix style and formatting comments.
>> 
>> Makefile.util.def            |  10 +++-
>> grub-core/Makefile.core.def  |  10 +++-
>> grub-core/fs/btrfs.c         | 112 ++++++++++++++++++++++++++++++++++-
>> tests/btrfs_test.in          |   1 +
>> tests/util/grub-fs-tester.in |   2 +-
>> 5 files changed, 131 insertions(+), 4 deletions(-)
>> 
>> diff --git a/Makefile.util.def b/Makefile.util.def
>> index f9caccb97..27c5e9903 100644
>> --- a/Makefile.util.def
>> +++ b/Makefile.util.def
>> @@ -54,7 +54,7 @@ library = {
>> library = {
>>   name = libgrubmods.a;
>>   cflags = '-fno-builtin -Wno-undef';
>> -  cppflags = '-I$(top_srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -DMINILZO_HAVE_CONFIG_H';
>> +  cppflags = '-I$(srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -I$(srcdir)/grub-core/lib/zstd -DMINILZO_HAVE_CONFIG_H';
>> 
>>   common_nodist = grub_script.tab.c;
>>   common_nodist = grub_script.yy.c;
>> @@ -164,6 +164,14 @@ library = {
>>   common = grub-core/lib/xzembed/xz_dec_bcj.c;
>>   common = grub-core/lib/xzembed/xz_dec_lzma2.c;
>>   common = grub-core/lib/xzembed/xz_dec_stream.c;
>> +  common = grub-core/lib/zstd/debug.c;
>> +  common = grub-core/lib/zstd/entropy_common.c;
>> +  common = grub-core/lib/zstd/error_private.c;
>> +  common = grub-core/lib/zstd/fse_decompress.c;
>> +  common = grub-core/lib/zstd/huf_decompress.c;
>> +  common = grub-core/lib/zstd/xxhash.c;
>> +  common = grub-core/lib/zstd/zstd_common.c;
>> +  common = grub-core/lib/zstd/zstd_decompress.c;
>> };
>> 
>> program = {
>> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
>> index 2c1d62cee..f818f58bc 100644
>> --- a/grub-core/Makefile.core.def
>> +++ b/grub-core/Makefile.core.def
>> @@ -1265,8 +1265,16 @@ module = {
>>   name = btrfs;
>>   common = fs/btrfs.c;
>>   common = lib/crc.c;
>> +  common = lib/zstd/debug.c;
>> +  common = lib/zstd/entropy_common.c;
>> +  common = lib/zstd/error_private.c;
>> +  common = lib/zstd/fse_decompress.c;
>> +  common = lib/zstd/huf_decompress.c;
>> +  common = lib/zstd/xxhash.c;
>> +  common = lib/zstd/zstd_common.c;
>> +  common = lib/zstd/zstd_decompress.c;
>>   cflags = '$(CFLAGS_POSIX) -Wno-undef';
>> -  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -DMINILZO_HAVE_CONFIG_H';
>> +  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -I$(srcdir)/lib/zstd -DMINILZO_HAVE_CONFIG_H';
>> };
> 
> Please do not embed zstd lib into btrfs module here.
> I would like to see zstd lib as separate module if possible.

Sure, I'm not exactly sure how the build system works. I haven't been able to
find any documentation, if there is some can you point me to it? I think the zstd
module should look like:

module = {
  name = zstd;
  common = lib/zstd/debug.c;
  common = lib/zstd/entropy_common.c;
  common = lib/zstd/error_private.c;
  common = lib/zstd/fse_decompress.c;
  common = lib/zstd/huf_decompress.c;
  common = lib/zstd/xxhash.c;
  common = lib/zstd/zstd_common.c;
  common = lib/zstd/zstd_decompress.c;
  cflags = '$(CFLAGS_POSIX) -Wno-undef';
  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/zstd';
};

Then how do I add a dependency on it in btrfs?


>> +static grub_ssize_t
>> +grub_btrfs_zstd_decompress (char *ibuf, grub_size_t isize, grub_off_t off,
>> +			    char *obuf, grub_size_t osize)
>> +{
>> +	void *allocated = NULL;
>> +	char *otmpbuf = obuf;
>> +	grub_size_t otmpsize = osize;
>> +	ZSTD_DCtx *dctx = NULL;
>> +	grub_size_t zstd_ret;
>> +	grub_ssize_t ret = -1;
>> +
>> +	/*
>> +	 * Zstd will fail if it can't fit the entire output in the destination
>> +	 * buffer, so if osize isn't large enough, allocate a temporary buffer.
>> +	 */
>> +	if (otmpsize < ZSTD_BTRFS_MAX_INPUT) {
>> +		allocated = grub_malloc (ZSTD_BTRFS_MAX_INPUT);
>> +		if (!allocated) {
> 
> Hmmm... Should not we say something here? Like grub_error() call below?
> It seems to me that failing silently is bad idea here.

grub_malloc() already calls grub_error with the message "Out of memory".

Thanks,
Nick

Patch
diff mbox series

diff --git a/Makefile.util.def b/Makefile.util.def
index f9caccb97..27c5e9903 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -54,7 +54,7 @@  library = {
 library = {
   name = libgrubmods.a;
   cflags = '-fno-builtin -Wno-undef';
-  cppflags = '-I$(top_srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -DMINILZO_HAVE_CONFIG_H';
+  cppflags = '-I$(srcdir)/grub-core/lib/minilzo -I$(srcdir)/grub-core/lib/xzembed -I$(srcdir)/grub-core/lib/zstd -DMINILZO_HAVE_CONFIG_H';

   common_nodist = grub_script.tab.c;
   common_nodist = grub_script.yy.c;
@@ -164,6 +164,14 @@  library = {
   common = grub-core/lib/xzembed/xz_dec_bcj.c;
   common = grub-core/lib/xzembed/xz_dec_lzma2.c;
   common = grub-core/lib/xzembed/xz_dec_stream.c;
+  common = grub-core/lib/zstd/debug.c;
+  common = grub-core/lib/zstd/entropy_common.c;
+  common = grub-core/lib/zstd/error_private.c;
+  common = grub-core/lib/zstd/fse_decompress.c;
+  common = grub-core/lib/zstd/huf_decompress.c;
+  common = grub-core/lib/zstd/xxhash.c;
+  common = grub-core/lib/zstd/zstd_common.c;
+  common = grub-core/lib/zstd/zstd_decompress.c;
 };

 program = {
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 2c1d62cee..f818f58bc 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1265,8 +1265,16 @@  module = {
   name = btrfs;
   common = fs/btrfs.c;
   common = lib/crc.c;
+  common = lib/zstd/debug.c;
+  common = lib/zstd/entropy_common.c;
+  common = lib/zstd/error_private.c;
+  common = lib/zstd/fse_decompress.c;
+  common = lib/zstd/huf_decompress.c;
+  common = lib/zstd/xxhash.c;
+  common = lib/zstd/zstd_common.c;
+  common = lib/zstd/zstd_decompress.c;
   cflags = '$(CFLAGS_POSIX) -Wno-undef';
-  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -DMINILZO_HAVE_CONFIG_H';
+  cppflags = '-I$(srcdir)/lib/posix_wrap -I$(srcdir)/lib/minilzo -I$(srcdir)/lib/zstd -DMINILZO_HAVE_CONFIG_H';
 };

 module = {
diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
index 4849c1ceb..c44fe8029 100644
--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -17,6 +17,8 @@ 
  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  */

+#define ZSTD_STATIC_LINKING_ONLY
+
 #include <grub/err.h>
 #include <grub/file.h>
 #include <grub/mm.h>
@@ -27,6 +29,7 @@ 
 #include <grub/lib/crc.h>
 #include <grub/deflate.h>
 #include <minilzo.h>
+#include <zstd.h>
 #include <grub/i18n.h>
 #include <grub/btrfs.h>

@@ -45,6 +48,9 @@  GRUB_MOD_LICENSE ("GPLv3+");
 #define GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE (GRUB_BTRFS_LZO_BLOCK_SIZE + \
 				     (GRUB_BTRFS_LZO_BLOCK_SIZE / 16) + 64 + 3)

+#define ZSTD_BTRFS_MAX_WINDOWLOG 17
+#define ZSTD_BTRFS_MAX_INPUT     (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
+
 typedef grub_uint8_t grub_btrfs_checksum_t[0x20];
 typedef grub_uint16_t grub_btrfs_uuid_t[8];

@@ -212,6 +218,7 @@  struct grub_btrfs_extent_data
 #define GRUB_BTRFS_COMPRESSION_NONE 0
 #define GRUB_BTRFS_COMPRESSION_ZLIB 1
 #define GRUB_BTRFS_COMPRESSION_LZO  2
+#define GRUB_BTRFS_COMPRESSION_ZSTD 3

 #define GRUB_BTRFS_OBJECT_ID_CHUNK 0x100

@@ -912,6 +919,95 @@  grub_btrfs_read_inode (struct grub_btrfs_data *data,
   return grub_btrfs_read_logical (data, elemaddr, inode, sizeof (*inode), 0);
 }

+static void* grub_zstd_malloc (void* state, size_t size)
+{
+	(void)state;
+
+	return grub_malloc (size);
+}
+
+static void grub_zstd_free (void* state, void* address)
+{
+	(void)state;
+
+	return grub_free (address);
+}
+
+static ZSTD_customMem grub_zstd_allocator (void)
+{
+	ZSTD_customMem allocator;
+
+	allocator.customAlloc = &grub_zstd_malloc;
+	allocator.customFree = &grub_zstd_free;
+	allocator.opaque = NULL;
+
+	return allocator;
+}
+
+static grub_ssize_t
+grub_btrfs_zstd_decompress (char *ibuf, grub_size_t isize, grub_off_t off,
+			    char *obuf, grub_size_t osize)
+{
+	void *allocated = NULL;
+	char *otmpbuf = obuf;
+	grub_size_t otmpsize = osize;
+	ZSTD_DCtx *dctx = NULL;
+	grub_size_t zstd_ret;
+	grub_ssize_t ret = -1;
+
+	/*
+	 * Zstd will fail if it can't fit the entire output in the destination
+	 * buffer, so if osize isn't large enough, allocate a temporary buffer.
+	 */
+	if (otmpsize < ZSTD_BTRFS_MAX_INPUT) {
+		allocated = grub_malloc (ZSTD_BTRFS_MAX_INPUT);
+		if (!allocated) {
+			goto err;
+		}
+		otmpbuf = (char*)allocated;
+		otmpsize = ZSTD_BTRFS_MAX_INPUT;
+	}
+
+	/* Create the ZSTD_DCtx. */
+	dctx = ZSTD_createDCtx_advanced (grub_zstd_allocator ());
+	if (!dctx) {
+		grub_error (GRUB_ERR_OUT_OF_MEMORY, "zstd out of memory");
+		goto err;
+	}
+
+	/*
+	 * Get the real input size, there may be junk at the
+	 * end of the frame.
+	 */
+	isize = ZSTD_findFrameCompressedSize (ibuf, isize);
+	if (ZSTD_isError (isize)) {
+		grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
+			    "zstd data corrupted");
+		goto err;
+	}
+
+	/* Decompress and check for errors. */
+	zstd_ret = ZSTD_decompressDCtx (dctx, otmpbuf, otmpsize, ibuf, isize);
+	if (ZSTD_isError (zstd_ret)) {
+		grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
+			    "zstd data corrupted");
+		goto err;
+	}
+
+	/*
+	 * Move the requested data into the obuf. obuf may be equal
+	 * to otmpbuf, which is why grub_memmove() is required.
+	 */
+	grub_memmove (obuf, otmpbuf + off, osize);
+	ret = osize;
+
+err:
+	grub_free (allocated);
+	ZSTD_freeDCtx (dctx);
+
+	return ret;
+}
+
 static grub_ssize_t
 grub_btrfs_lzo_decompress(char *ibuf, grub_size_t isize, grub_off_t off,
 			  char *obuf, grub_size_t osize)
@@ -1087,7 +1183,8 @@  grub_btrfs_extent_read (struct grub_btrfs_data *data,

       if (data->extent->compression != GRUB_BTRFS_COMPRESSION_NONE
 	  && data->extent->compression != GRUB_BTRFS_COMPRESSION_ZLIB
-	  && data->extent->compression != GRUB_BTRFS_COMPRESSION_LZO)
+	  && data->extent->compression != GRUB_BTRFS_COMPRESSION_LZO
+	  && data->extent->compression != GRUB_BTRFS_COMPRESSION_ZSTD)
 	{
 	  grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 		      "compression type 0x%x not supported",
@@ -1127,6 +1224,15 @@  grub_btrfs_extent_read (struct grub_btrfs_data *data,
 		  != (grub_ssize_t) csize)
 		return -1;
 	    }
+	  else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_ZSTD)
+	    {
+	      if (grub_btrfs_zstd_decompress(data->extent->inl, data->extsize -
+					     ((grub_uint8_t *) data->extent->inl
+					      - (grub_uint8_t *) data->extent),
+					     extoff, buf, csize)
+		  != (grub_ssize_t) csize)
+		return -1;
+	    }
 	  else
 	    grub_memcpy (buf, data->extent->inl + extoff, csize);
 	  break;
@@ -1164,6 +1270,10 @@  grub_btrfs_extent_read (struct grub_btrfs_data *data,
 		ret = grub_btrfs_lzo_decompress (tmp, zsize, extoff
 				    + grub_le_to_cpu64 (data->extent->offset),
 				    buf, csize);
+	      else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_ZSTD)
+		ret = grub_btrfs_zstd_decompress (tmp, zsize, extoff
+				    + grub_le_to_cpu64 (data->extent->offset),
+				    buf, csize);
 	      else
 		ret = -1;

diff --git a/tests/btrfs_test.in b/tests/btrfs_test.in
index 2b37ddd33..0c9bf3a68 100644
--- a/tests/btrfs_test.in
+++ b/tests/btrfs_test.in
@@ -18,6 +18,7 @@  fi
 "@builddir@/grub-fs-tester" btrfs
 "@builddir@/grub-fs-tester" btrfs_zlib
 "@builddir@/grub-fs-tester" btrfs_lzo
+"@builddir@/grub-fs-tester" btrfs_zstd
 "@builddir@/grub-fs-tester" btrfs_raid0
 "@builddir@/grub-fs-tester" btrfs_raid1
 "@builddir@/grub-fs-tester" btrfs_single
diff --git a/tests/util/grub-fs-tester.in b/tests/util/grub-fs-tester.in
index 15969d796..3470c89e3 100644
--- a/tests/util/grub-fs-tester.in
+++ b/tests/util/grub-fs-tester.in
@@ -626,7 +626,7 @@  for LOGSECSIZE in $(range "$MINLOGSECSIZE" "$MAXLOGSECSIZE" 1); do
 		    ;;
 		x"btrfs")
 		    "mkfs.btrfs" -s $SECSIZE -L "$FSLABEL" "${MOUNTDEVICE}" ;;
-		x"btrfs_zlib" | x"btrfs_lzo")
+		x"btrfs_zlib" | x"btrfs_lzo" | x"btrfs_zstd")
 		    "mkfs.btrfs" -s $SECSIZE -L "$FSLABEL" "${MOUNTDEVICE}"
 		    MOUNTOPTS="compress=${fs/btrfs_/},"
 		    MOUNTFS="btrfs"