btrfs: Add zstd support to grub btrfs

- Adds zstd support to the btrfs module.
- Adds a test case for btrfs zstd support.
- Changes top_srcdir to srcdir in the btrfs module's lzo include
  following comments from Daniel Kiper about the zstd include.

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>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Nick Terrell 2018-11-19 11:20:08 -08:00 committed by Daniel Kiper
parent 461f1d8af1
commit 3861286486
5 changed files with 131 additions and 4 deletions

View file

@ -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;
@ -165,6 +165,15 @@ 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/module.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 = {

View file

@ -1291,7 +1291,7 @@ module = {
common = fs/btrfs.c;
common = lib/crc.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 = {

View file

@ -17,6 +17,14 @@
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Tell zstd to expose functions that aren't part of the stable API, which
* aren't safe to use when linking against a dynamic library. We vendor in a
* specific zstd version, so we know what we're getting. We need these unstable
* functions to provide our own allocator, which uses grub_malloc(), to zstd.
*/
#define ZSTD_STATIC_LINKING_ONLY
#include <grub/err.h>
#include <grub/file.h>
#include <grub/mm.h>
@ -27,6 +35,7 @@
#include <grub/lib/crc.h>
#include <grub/deflate.h>
#include <minilzo.h>
#include <zstd.h>
#include <grub/i18n.h>
#include <grub/btrfs.h>
#include <grub/crypto.h>
@ -47,6 +56,9 @@ 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];
@ -217,6 +229,7 @@ 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
@ -1216,6 +1229,96 @@ 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 __attribute__((unused)), size_t size)
{
return grub_malloc (size);
}
static void grub_zstd_free (void *state __attribute__((unused)), void *address)
{
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)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "failed allocate a zstd buffer");
goto err;
}
otmpbuf = (char *) allocated;
otmpsize = ZSTD_BTRFS_MAX_INPUT;
}
/* Create the ZSTD_DCtx. */
dctx = ZSTD_createDCtx_advanced (grub_zstd_allocator ());
if (!dctx)
{
/* ZSTD_createDCtx_advanced() only fails if it is out of memory. */
grub_error (GRUB_ERR_OUT_OF_MEMORY, "failed to create a zstd context");
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)
@ -1391,7 +1494,8 @@ 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",
@ -1431,6 +1535,15 @@ 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;
@ -1468,6 +1581,10 @@ 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;

View file

@ -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

View file

@ -629,7 +629,7 @@ 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"