From 386128648606a3aa6ae7108d1c9af52258202279 Mon Sep 17 00:00:00 2001 From: Nick Terrell Date: Mon, 19 Nov 2018 11:20:08 -0800 Subject: [PATCH] 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 Reviewed-by: Daniel Kiper --- Makefile.util.def | 11 +++- grub-core/Makefile.core.def | 2 +- grub-core/fs/btrfs.c | 119 ++++++++++++++++++++++++++++++++++- 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 9ae45f351..a0495a87f 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$(srcdir)/grub-core/lib/zstd -DMINILZO_HAVE_CONFIG_H'; common_nodist = grub_script.tab.c; common_nodist = grub_script.yy.c; @@ -165,6 +165,15 @@ library = { common = grub-core/lib/xzembed/xz_dec_bcj.c; common = grub-core/lib/xzembed/xz_dec_lzma2.c; common = grub-core/lib/xzembed/xz_dec_stream.c; + common = grub-core/lib/zstd/debug.c; + common = grub-core/lib/zstd/entropy_common.c; + common = grub-core/lib/zstd/error_private.c; + common = grub-core/lib/zstd/fse_decompress.c; + common = grub-core/lib/zstd/huf_decompress.c; + common = grub-core/lib/zstd/module.c; + common = grub-core/lib/zstd/xxhash.c; + common = grub-core/lib/zstd/zstd_common.c; + common = grub-core/lib/zstd/zstd_decompress.c; }; program = { diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def index 829e7bb57..2d75c4daf 100644 --- a/grub-core/Makefile.core.def +++ b/grub-core/Makefile.core.def @@ -1291,7 +1291,7 @@ module = { common = fs/btrfs.c; common = lib/crc.c; cflags = '$(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 = { diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c index cac9ef588..3d6d11ec5 100644 --- a/grub-core/fs/btrfs.c +++ b/grub-core/fs/btrfs.c @@ -17,6 +17,14 @@ * along with GRUB. If not, see . */ +/* + * 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 #include #include @@ -27,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -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; 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 ef65fbc93..bc14a05ca 100644 --- a/tests/util/grub-fs-tester.in +++ b/tests/util/grub-fs-tester.in @@ -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"