diff --git a/contrib/linux-kernel/0000-cover-letter.patch b/contrib/linux-kernel/0000-cover-letter.patch
index 763b5a9c..33a5189b 100644
--- a/contrib/linux-kernel/0000-cover-letter.patch
+++ b/contrib/linux-kernel/0000-cover-letter.patch
@@ -1,7 +1,7 @@
-From 8bc9a0ae5c86a6d02d9a5274b9965ddac0e8d330 Mon Sep 17 00:00:00 2001
+From 0cd63464d182bb9708f8b25f7da3dc8e5ec6b4fa Mon Sep 17 00:00:00 2001
 From: Nick Terrell <terrelln@fb.com>
-Date: Wed, 28 Jun 2017 22:00:00 -0700
-Subject: [PATCH v2 0/4] Add xxhash and zstd modules
+Date: Thu, 20 Jul 2017 13:18:30 -0700
+Subject: [PATCH v3 0/4] Add xxhash and zstd modules
 
 Hi all,
 
@@ -24,6 +24,13 @@ v1 -> v2:
   HUF_compressWeights(), HUF_readDTableX2(), and HUF_readDTableX4() (2/4)
 - No zstd function uses more than 400 B of stack space (2/4)
 
+v2 -> v3:
+- Work around gcc-7 bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388
+  (2/4)
+- Fix bug in dictionary compression from upstream commit cc1522351f (2/4)
+- Port upstream BtrFS commits e1ddce71d6, 389a6cfc2a, and 6acafd1eff (3/4)
+- Change default compression level for BtrFS to 3 (3/4)
+
 Nick Terrell (4):
   lib: Add xxhash module
   lib: Add zstd modules
@@ -40,7 +47,7 @@ Nick Terrell (4):
  fs/btrfs/props.c           |    6 +
  fs/btrfs/super.c           |   12 +-
  fs/btrfs/sysfs.c           |    2 +
- fs/btrfs/zstd.c            |  433 ++++++
+ fs/btrfs/zstd.c            |  435 ++++++
  fs/squashfs/Kconfig        |   14 +
  fs/squashfs/Makefile       |    1 +
  fs/squashfs/decompressor.c |    7 +
@@ -63,13 +70,13 @@ Nick Terrell (4):
  lib/zstd/fse_compress.c    |  795 ++++++++++
  lib/zstd/fse_decompress.c  |  332 +++++
  lib/zstd/huf.h             |  212 +++
- lib/zstd/huf_compress.c    |  771 ++++++++++
+ lib/zstd/huf_compress.c    |  770 ++++++++++
  lib/zstd/huf_decompress.c  |  960 ++++++++++++
  lib/zstd/mem.h             |  151 ++
  lib/zstd/zstd_common.c     |   75 +
- lib/zstd/zstd_internal.h   |  269 ++++
+ lib/zstd/zstd_internal.h   |  250 ++++
  lib/zstd/zstd_opt.h        | 1014 +++++++++++++
- 39 files changed, 14400 insertions(+), 12 deletions(-)
+ 39 files changed, 14382 insertions(+), 12 deletions(-)
  create mode 100644 fs/btrfs/zstd.c
  create mode 100644 fs/squashfs/zstd_wrapper.c
  create mode 100644 include/linux/xxhash.h
diff --git a/contrib/linux-kernel/0001-lib-Add-xxhash-module.patch b/contrib/linux-kernel/0001-lib-Add-xxhash-module.patch
index 84a2c53c..f86731ce 100644
--- a/contrib/linux-kernel/0001-lib-Add-xxhash-module.patch
+++ b/contrib/linux-kernel/0001-lib-Add-xxhash-module.patch
@@ -1,7 +1,7 @@
-From 5ac909c415ab4a18fd90794793c96e450795e8c6 Mon Sep 17 00:00:00 2001
+From fc7f26acbabda35f1c61dfc357dbb207dc8ed23d Mon Sep 17 00:00:00 2001
 From: Nick Terrell <terrelln@fb.com>
-Date: Wed, 21 Jun 2017 17:37:36 -0700
-Subject: [PATCH v2 1/4] lib: Add xxhash module
+Date: Mon, 17 Jul 2017 17:07:18 -0700
+Subject: [PATCH v3 1/4] lib: Add xxhash module
 
 Adds xxhash kernel module with xxh32 and xxh64 hashes. xxhash is an
 extremely fast non-cryptographic hash algorithm for checksumming.
@@ -327,10 +327,10 @@ index 0000000..9e1f42c
 +
 +#endif /* XXHASH_H */
 diff --git a/lib/Kconfig b/lib/Kconfig
-index 0c8b78a..b6009d7 100644
+index 6762529..5e7541f 100644
 --- a/lib/Kconfig
 +++ b/lib/Kconfig
-@@ -184,6 +184,9 @@ config CRC8
+@@ -192,6 +192,9 @@ config CRC8
  	  when they need to do cyclic redundancy check according CRC8
  	  algorithm. Module will be called crc8.
 
@@ -341,10 +341,10 @@ index 0c8b78a..b6009d7 100644
  	bool
  	depends on AUDIT && !AUDIT_ARCH
 diff --git a/lib/Makefile b/lib/Makefile
-index 0166fbc..1338226 100644
+index 40c1837..d06b68a 100644
 --- a/lib/Makefile
 +++ b/lib/Makefile
-@@ -102,6 +102,7 @@ obj-$(CONFIG_CRC32_SELFTEST)	+= crc32test.o
+@@ -102,6 +102,7 @@ obj-$(CONFIG_CRC4)	+= crc4.o
  obj-$(CONFIG_CRC7)	+= crc7.o
  obj-$(CONFIG_LIBCRC32C)	+= libcrc32c.o
  obj-$(CONFIG_CRC8)	+= crc8.o
diff --git a/contrib/linux-kernel/0002-lib-Add-zstd-modules.patch b/contrib/linux-kernel/0002-lib-Add-zstd-modules.patch
index 97109399..268307cf 100644
--- a/contrib/linux-kernel/0002-lib-Add-zstd-modules.patch
+++ b/contrib/linux-kernel/0002-lib-Add-zstd-modules.patch
@@ -1,7 +1,7 @@
-From d2626127c6d6e60e940dd9a3ed58323bdcdc4930 Mon Sep 17 00:00:00 2001
+From 686a6149b98250d66b5951e3ae05e79063e9de98 Mon Sep 17 00:00:00 2001
 From: Nick Terrell <terrelln@fb.com>
-Date: Tue, 16 May 2017 14:55:36 -0700
-Subject: [PATCH v2 2/4] lib: Add zstd modules
+Date: Mon, 17 Jul 2017 17:08:19 -0700
+Subject: [PATCH v3 2/4] lib: Add zstd modules
 
 Add zstd compression and decompression kernel modules.
 zstd offers a wide varity of compression speed and quality trade-offs.
@@ -110,6 +110,10 @@ v1 -> v2:
   HUF_compressWeights(), HUF_readDTableX2(), and HUF_readDTableX4()
 - No function uses more than 400 B of stack space
 
+v2 -> v3:
+- Work around gcc-7 bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388
+- Fix bug in dictionary compression from upstream commit cc1522351f
+
  include/linux/zstd.h      | 1157 +++++++++++++++
  lib/Kconfig               |    8 +
  lib/Makefile              |    2 +
@@ -123,13 +127,13 @@ v1 -> v2:
  lib/zstd/fse_compress.c   |  795 +++++++++++
  lib/zstd/fse_decompress.c |  332 +++++
  lib/zstd/huf.h            |  212 +++
- lib/zstd/huf_compress.c   |  771 ++++++++++
+ lib/zstd/huf_compress.c   |  770 ++++++++++
  lib/zstd/huf_decompress.c |  960 +++++++++++++
  lib/zstd/mem.h            |  151 ++
  lib/zstd/zstd_common.c    |   75 +
- lib/zstd/zstd_internal.h  |  269 ++++
+ lib/zstd/zstd_internal.h  |  250 ++++
  lib/zstd/zstd_opt.h       | 1014 +++++++++++++
- 19 files changed, 13014 insertions(+)
+ 19 files changed, 12994 insertions(+)
  create mode 100644 include/linux/zstd.h
  create mode 100644 lib/zstd/Makefile
  create mode 100644 lib/zstd/bitstream.h
@@ -1312,10 +1316,10 @@ index 0000000..249575e
 +
 +#endif  /* ZSTD_H */
 diff --git a/lib/Kconfig b/lib/Kconfig
-index b6009d7..f00ddab 100644
+index 5e7541f..0d49ed0 100644
 --- a/lib/Kconfig
 +++ b/lib/Kconfig
-@@ -241,6 +241,14 @@ config LZ4HC_COMPRESS
+@@ -249,6 +249,14 @@ config LZ4HC_COMPRESS
  config LZ4_DECOMPRESS
  	tristate
 
@@ -1331,7 +1335,7 @@ index b6009d7..f00ddab 100644
 
  #
 diff --git a/lib/Makefile b/lib/Makefile
-index 1338226..4fcef16 100644
+index d06b68a..d5c8a4f 100644
 --- a/lib/Makefile
 +++ b/lib/Makefile
 @@ -116,6 +116,8 @@ obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
@@ -10012,10 +10016,10 @@ index 0000000..2143da2
 +#endif /* HUF_H_298734234 */
 diff --git a/lib/zstd/huf_compress.c b/lib/zstd/huf_compress.c
 new file mode 100644
-index 0000000..0361f38
+index 0000000..40055a7
 --- /dev/null
 +++ b/lib/zstd/huf_compress.c
-@@ -0,0 +1,771 @@
+@@ -0,0 +1,770 @@
 +/*
 + * Huffman encoder, part of New Generation Entropy library
 + * Copyright (C) 2013-2016, Yann Collet.
@@ -10543,7 +10547,7 @@ index 0000000..0361f38
 +
 +size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
 +
-+#define HUF_FLUSHBITS(s) (fast ? BIT_flushBitsFast(s) : BIT_flushBits(s))
++#define HUF_FLUSHBITS(s)  BIT_flushBits(s)
 +
 +#define HUF_FLUSHBITS_1(stream)                                            \
 +	if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 2 + 7) \
@@ -10560,7 +10564,6 @@ index 0000000..0361f38
 +	BYTE *const oend = ostart + dstSize;
 +	BYTE *op = ostart;
 +	size_t n;
-+	const unsigned fast = (dstSize >= HUF_BLOCKBOUND(srcSize));
 +	BIT_CStream_t bitC;
 +
 +	/* init */
@@ -11993,10 +11996,10 @@ index 0000000..a282624
 +}
 diff --git a/lib/zstd/zstd_internal.h b/lib/zstd/zstd_internal.h
 new file mode 100644
-index 0000000..6748719
+index 0000000..f0ba474
 --- /dev/null
 +++ b/lib/zstd/zstd_internal.h
-@@ -0,0 +1,269 @@
+@@ -0,0 +1,250 @@
 +/**
 + * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
 + * All rights reserved.
@@ -12125,35 +12128,16 @@ index 0000000..6748719
 +/*-*******************************************
 +*  Shared functions to include for inlining
 +*********************************************/
-+static void ZSTD_copy8(void *dst, const void *src) { memcpy(dst, src, 8); }
-+#define COPY8(d, s)               \
-+	{                         \
-+		ZSTD_copy8(d, s); \
-+		d += 8;           \
-+		s += 8;           \
-+	}
-+
++static void ZSTD_copy8(void *dst, const void *src) {
++	memcpy(dst, src, 8);
++}
 +/*! ZSTD_wildcopy() :
 +*   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
 +#define WILDCOPY_OVERLENGTH 8
 +ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length)
 +{
-+	const BYTE *ip = (const BYTE *)src;
-+	BYTE *op = (BYTE *)dst;
-+	BYTE *const oend = op + length;
-+	do
-+		COPY8(op, ip)
-+	while (op < oend);
-+}
-+
-+ZSTD_STATIC void ZSTD_wildcopy_e(void *dst, const void *src, void *dstEnd) /* should be faster for decoding, but strangely, not verified on all platform */
-+{
-+	const BYTE *ip = (const BYTE *)src;
-+	BYTE *op = (BYTE *)dst;
-+	BYTE *const oend = (BYTE *)dstEnd;
-+	do
-+		COPY8(op, ip)
-+	while (op < oend);
++	if (length > 0)
++		memcpy(dst, src, length);
 +}
 +
 +/*-*******************************************
diff --git a/contrib/linux-kernel/0003-btrfs-Add-zstd-support.patch b/contrib/linux-kernel/0003-btrfs-Add-zstd-support.patch
index abc8326c..5578fa38 100644
--- a/contrib/linux-kernel/0003-btrfs-Add-zstd-support.patch
+++ b/contrib/linux-kernel/0003-btrfs-Add-zstd-support.patch
@@ -1,7 +1,7 @@
-From 599f8f2aaace3df939cb145368574a52268d82d0 Mon Sep 17 00:00:00 2001
+From b0ef8fc63c9ca251ceca632f53aa1de8f1f17772 Mon Sep 17 00:00:00 2001
 From: Nick Terrell <terrelln@fb.com>
-Date: Wed, 21 Jun 2017 17:31:39 -0700
-Subject: [PATCH v2 3/4] btrfs: Add zstd support
+Date: Mon, 17 Jul 2017 17:08:39 -0700
+Subject: [PATCH v3 3/4] btrfs: Add zstd support
 
 Add zstd compression and decompression support to BtrFS. zstd at its
 fastest level compresses almost as well as zlib, while offering much
@@ -63,6 +63,10 @@ zstd source repository: https://github.com/facebook/zstd
 
 Signed-off-by: Nick Terrell <terrelln@fb.com>
 ---
+v2 -> v3:
+- Port upstream BtrFS commits e1ddce71d6, 389a6cfc2a, and 6acafd1eff
+- Change default compression level for BtrFS to 3
+
  fs/btrfs/Kconfig           |   2 +
  fs/btrfs/Makefile          |   2 +-
  fs/btrfs/compression.c     |   1 +
@@ -73,9 +77,9 @@ Signed-off-by: Nick Terrell <terrelln@fb.com>
  fs/btrfs/props.c           |   6 +
  fs/btrfs/super.c           |  12 +-
  fs/btrfs/sysfs.c           |   2 +
- fs/btrfs/zstd.c            | 433 +++++++++++++++++++++++++++++++++++++++++++++
+ fs/btrfs/zstd.c            | 435 +++++++++++++++++++++++++++++++++++++++++++++
  include/uapi/linux/btrfs.h |   8 +-
- 12 files changed, 469 insertions(+), 12 deletions(-)
+ 12 files changed, 471 insertions(+), 12 deletions(-)
  create mode 100644 fs/btrfs/zstd.c
 
 diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
@@ -105,10 +109,10 @@ index 128ce17..962a95a 100644
  	   reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
  	   uuid-tree.o props.o hash.o free-space-tree.o
 diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
-index 10e6b28..3beb0d0 100644
+index d2ef9ac..4ff42d1 100644
 --- a/fs/btrfs/compression.c
 +++ b/fs/btrfs/compression.c
-@@ -761,6 +761,7 @@ static struct {
+@@ -704,6 +704,7 @@ static struct {
  static const struct btrfs_compress_op * const btrfs_compress_op[] = {
  	&btrfs_zlib_compress,
  	&btrfs_lzo_compress,
@@ -117,10 +121,10 @@ index 10e6b28..3beb0d0 100644
 
  void __init btrfs_init_compress(void)
 diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
-index 39ec43a..d99fc21 100644
+index 87f6d33..2269e00 100644
 --- a/fs/btrfs/compression.h
 +++ b/fs/btrfs/compression.h
-@@ -60,8 +60,9 @@ enum btrfs_compression_type {
+@@ -99,8 +99,9 @@ enum btrfs_compression_type {
  	BTRFS_COMPRESS_NONE  = 0,
  	BTRFS_COMPRESS_ZLIB  = 1,
  	BTRFS_COMPRESS_LZO   = 2,
@@ -132,7 +136,7 @@ index 39ec43a..d99fc21 100644
  };
 
  struct btrfs_compress_op {
-@@ -92,5 +93,6 @@ struct btrfs_compress_op {
+@@ -128,5 +129,6 @@ struct btrfs_compress_op {
 
  extern const struct btrfs_compress_op btrfs_zlib_compress;
  extern const struct btrfs_compress_op btrfs_lzo_compress;
@@ -140,10 +144,10 @@ index 39ec43a..d99fc21 100644
 
  #endif
 diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
-index 4f8f75d..61dd3dd 100644
+index 3f3eb7b..845d77c 100644
 --- a/fs/btrfs/ctree.h
 +++ b/fs/btrfs/ctree.h
-@@ -271,6 +271,7 @@ struct btrfs_super_block {
+@@ -270,6 +270,7 @@ struct btrfs_super_block {
  	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
  	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
  	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
@@ -152,10 +156,10 @@ index 4f8f75d..61dd3dd 100644
  	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
  	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
 diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
-index 5f678dc..49c0e91 100644
+index 080e2eb..04632f4 100644
 --- a/fs/btrfs/disk-io.c
 +++ b/fs/btrfs/disk-io.c
-@@ -2831,6 +2831,8 @@ int open_ctree(struct super_block *sb,
+@@ -2828,6 +2828,8 @@ int open_ctree(struct super_block *sb,
  	features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
  	if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
  		features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
@@ -165,7 +169,7 @@ index 5f678dc..49c0e91 100644
  	if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
  		btrfs_info(fs_info, "has skinny extents");
 diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
-index e176375..f732cfd 100644
+index fa1b78c..b9963d9 100644
 --- a/fs/btrfs/ioctl.c
 +++ b/fs/btrfs/ioctl.c
 @@ -327,8 +327,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
@@ -180,7 +184,7 @@ index e176375..f732cfd 100644
  		ret = btrfs_set_prop(inode, "btrfs.compression",
  				     comp, strlen(comp), 0);
  		if (ret)
-@@ -1463,6 +1465,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
+@@ -1466,6 +1468,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 
  	if (range->compress_type == BTRFS_COMPRESS_LZO) {
  		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
@@ -190,10 +194,10 @@ index e176375..f732cfd 100644
 
  	ret = defrag_count;
 diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
-index d6cb155..162105f 100644
+index 4b23ae5..20631e9 100644
 --- a/fs/btrfs/props.c
 +++ b/fs/btrfs/props.c
-@@ -383,6 +383,8 @@ static int prop_compression_validate(const char *value, size_t len)
+@@ -390,6 +390,8 @@ static int prop_compression_validate(const char *value, size_t len)
  		return 0;
  	else if (!strncmp("zlib", value, len))
  		return 0;
@@ -202,7 +206,7 @@ index d6cb155..162105f 100644
 
  	return -EINVAL;
  }
-@@ -405,6 +407,8 @@ static int prop_compression_apply(struct inode *inode,
+@@ -412,6 +414,8 @@ static int prop_compression_apply(struct inode *inode,
  		type = BTRFS_COMPRESS_LZO;
  	else if (!strncmp("zlib", value, len))
  		type = BTRFS_COMPRESS_ZLIB;
@@ -211,7 +215,7 @@ index d6cb155..162105f 100644
  	else
  		return -EINVAL;
 
-@@ -422,6 +426,8 @@ static const char *prop_compression_extract(struct inode *inode)
+@@ -429,6 +433,8 @@ static const char *prop_compression_extract(struct inode *inode)
  		return "zlib";
  	case BTRFS_COMPRESS_LZO:
  		return "lzo";
@@ -221,7 +225,7 @@ index d6cb155..162105f 100644
 
  	return NULL;
 diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
-index 4f1cdd5..4f792d5 100644
+index 12540b6..c370dea 100644
 --- a/fs/btrfs/super.c
 +++ b/fs/btrfs/super.c
 @@ -513,6 +513,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
@@ -239,7 +243,7 @@ index 4f1cdd5..4f792d5 100644
  			} else if (strncmp(args[0].from, "no", 2) == 0) {
  				compress_type = "no";
  				btrfs_clear_opt(info->mount_opt, COMPRESS);
-@@ -1240,8 +1248,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
+@@ -1227,8 +1235,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
  	if (btrfs_test_opt(info, COMPRESS)) {
  		if (info->compress_type == BTRFS_COMPRESS_ZLIB)
  			compress_type = "zlib";
@@ -252,7 +256,7 @@ index 4f1cdd5..4f792d5 100644
  			seq_printf(seq, ",compress-force=%s", compress_type);
  		else
 diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
-index 1f157fb..b0dec90 100644
+index c2d5f35..2b6d37c 100644
 --- a/fs/btrfs/sysfs.c
 +++ b/fs/btrfs/sysfs.c
 @@ -200,6 +200,7 @@ BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
@@ -273,10 +277,10 @@ index 1f157fb..b0dec90 100644
  	BTRFS_FEAT_ATTR_PTR(raid56),
 diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
 new file mode 100644
-index 0000000..838741b
+index 0000000..1822068
 --- /dev/null
 +++ b/fs/btrfs/zstd.c
-@@ -0,0 +1,433 @@
+@@ -0,0 +1,435 @@
 +/*
 + * Copyright (c) 2016-present, Facebook, Inc.
 + * All rights reserved.
@@ -308,10 +312,11 @@ index 0000000..838741b
 +
 +#define ZSTD_BTRFS_MAX_WINDOWLOG 17
 +#define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
++#define ZSTD_BTRFS_DEFAULT_LEVEL 3
 +
 +static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
 +{
-+	ZSTD_parameters params = ZSTD_getParams(1, src_len, 0);
++	ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL, src_len, 0);
 +
 +	if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
 +		params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
@@ -330,7 +335,7 @@ index 0000000..838741b
 +{
 +	struct workspace *workspace = list_entry(ws, struct workspace, list);
 +
-+	vfree(workspace->mem);
++	kvfree(workspace->mem);
 +	kfree(workspace->buf);
 +	kfree(workspace);
 +}
@@ -341,15 +346,15 @@ index 0000000..838741b
 +			zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
 +	struct workspace *workspace;
 +
-+	workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
++	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
 +	if (!workspace)
 +		return ERR_PTR(-ENOMEM);
 +
 +	workspace->size = max_t(size_t,
 +			ZSTD_CStreamWorkspaceBound(params.cParams),
 +			ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
-+	workspace->mem = vmalloc(workspace->size);
-+	workspace->buf = kmalloc(PAGE_SIZE, GFP_NOFS);
++	workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
++	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 +	if (!workspace->mem || !workspace->buf)
 +		goto fail;
 +
@@ -541,12 +546,13 @@ index 0000000..838741b
 +	return ret;
 +}
 +
-+static int zstd_decompress_bio(struct list_head *ws, struct page **pages_in,
-+		u64 disk_start,
-+		struct bio *orig_bio,
-+		size_t srclen)
++static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 +{
 +	struct workspace *workspace = list_entry(ws, struct workspace, list);
++	struct page **pages_in = cb->compressed_pages;
++	u64 disk_start = cb->start;
++	struct bio *orig_bio = cb->orig_bio;
++	size_t srclen = cb->compressed_len;
 +	ZSTD_DStream *stream;
 +	int ret = 0;
 +	unsigned long page_in_index = 0;
@@ -711,7 +717,7 @@ index 0000000..838741b
 +	.decompress = zstd_decompress,
 +};
 diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
-index a456e53..992c150 100644
+index 9aa74f3..378230c 100644
 --- a/include/uapi/linux/btrfs.h
 +++ b/include/uapi/linux/btrfs.h
 @@ -255,13 +255,7 @@ struct btrfs_ioctl_fs_info_args {
diff --git a/contrib/linux-kernel/0004-squashfs-Add-zstd-support.patch b/contrib/linux-kernel/0004-squashfs-Add-zstd-support.patch
index b638194f..02bd1073 100644
--- a/contrib/linux-kernel/0004-squashfs-Add-zstd-support.patch
+++ b/contrib/linux-kernel/0004-squashfs-Add-zstd-support.patch
@@ -1,7 +1,7 @@
-From 5ff6a64abaea7b7f11d37cb0fdf08642316a3a90 Mon Sep 17 00:00:00 2001
+From 0cd63464d182bb9708f8b25f7da3dc8e5ec6b4fa Mon Sep 17 00:00:00 2001
 From: Nick Terrell <terrelln@fb.com>
-Date: Mon, 12 Jun 2017 12:18:23 -0700
-Subject: [PATCH v2 4/4] squashfs: Add zstd support
+Date: Mon, 17 Jul 2017 17:08:59 -0700
+Subject: [PATCH v3 4/4] squashfs: Add zstd support
 
 Add zstd compression and decompression support to SquashFS. zstd is a
 great fit for SquashFS because it can compress at ratios approaching xz,
diff --git a/contrib/linux-kernel/fs/btrfs/zstd.c b/contrib/linux-kernel/fs/btrfs/zstd.c
index 838741b3..18220687 100644
--- a/contrib/linux-kernel/fs/btrfs/zstd.c
+++ b/contrib/linux-kernel/fs/btrfs/zstd.c
@@ -29,10 +29,11 @@
 
 #define ZSTD_BTRFS_MAX_WINDOWLOG 17
 #define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
+#define ZSTD_BTRFS_DEFAULT_LEVEL 3
 
 static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
 {
-	ZSTD_parameters params = ZSTD_getParams(1, src_len, 0);
+	ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL, src_len, 0);
 
 	if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
 		params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
@@ -51,7 +52,7 @@ static void zstd_free_workspace(struct list_head *ws)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 
-	vfree(workspace->mem);
+	kvfree(workspace->mem);
 	kfree(workspace->buf);
 	kfree(workspace);
 }
@@ -62,15 +63,15 @@ static struct list_head *zstd_alloc_workspace(void)
 			zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
 	struct workspace *workspace;
 
-	workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
+	workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
 	if (!workspace)
 		return ERR_PTR(-ENOMEM);
 
 	workspace->size = max_t(size_t,
 			ZSTD_CStreamWorkspaceBound(params.cParams),
 			ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT));
-	workspace->mem = vmalloc(workspace->size);
-	workspace->buf = kmalloc(PAGE_SIZE, GFP_NOFS);
+	workspace->mem = kvmalloc(workspace->size, GFP_KERNEL);
+	workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!workspace->mem || !workspace->buf)
 		goto fail;
 
@@ -262,12 +263,13 @@ out:
 	return ret;
 }
 
-static int zstd_decompress_bio(struct list_head *ws, struct page **pages_in,
-		u64 disk_start,
-		struct bio *orig_bio,
-		size_t srclen)
+static int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
+	struct page **pages_in = cb->compressed_pages;
+	u64 disk_start = cb->start;
+	struct bio *orig_bio = cb->orig_bio;
+	size_t srclen = cb->compressed_len;
 	ZSTD_DStream *stream;
 	int ret = 0;
 	unsigned long page_in_index = 0;
diff --git a/contrib/linux-kernel/lib/zstd/huf_compress.c b/contrib/linux-kernel/lib/zstd/huf_compress.c
index 0361f387..40055a70 100644
--- a/contrib/linux-kernel/lib/zstd/huf_compress.c
+++ b/contrib/linux-kernel/lib/zstd/huf_compress.c
@@ -525,7 +525,7 @@ static void HUF_encodeSymbol(BIT_CStream_t *bitCPtr, U32 symbol, const HUF_CElt
 
 size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
 
-#define HUF_FLUSHBITS(s) (fast ? BIT_flushBitsFast(s) : BIT_flushBits(s))
+#define HUF_FLUSHBITS(s)  BIT_flushBits(s)
 
 #define HUF_FLUSHBITS_1(stream)                                            \
 	if (sizeof((stream)->bitContainer) * 8 < HUF_TABLELOG_MAX * 2 + 7) \
@@ -542,7 +542,6 @@ size_t HUF_compress1X_usingCTable(void *dst, size_t dstSize, const void *src, si
 	BYTE *const oend = ostart + dstSize;
 	BYTE *op = ostart;
 	size_t n;
-	const unsigned fast = (dstSize >= HUF_BLOCKBOUND(srcSize));
 	BIT_CStream_t bitC;
 
 	/* init */
diff --git a/contrib/linux-kernel/lib/zstd/zstd_internal.h b/contrib/linux-kernel/lib/zstd/zstd_internal.h
index 67487199..f0ba4744 100644
--- a/contrib/linux-kernel/lib/zstd/zstd_internal.h
+++ b/contrib/linux-kernel/lib/zstd/zstd_internal.h
@@ -126,35 +126,16 @@ static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;
 /*-*******************************************
 *  Shared functions to include for inlining
 *********************************************/
-static void ZSTD_copy8(void *dst, const void *src) { memcpy(dst, src, 8); }
-#define COPY8(d, s)               \
-	{                         \
-		ZSTD_copy8(d, s); \
-		d += 8;           \
-		s += 8;           \
-	}
-
+static void ZSTD_copy8(void *dst, const void *src) {
+	memcpy(dst, src, 8);
+}
 /*! ZSTD_wildcopy() :
 *   custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */
 #define WILDCOPY_OVERLENGTH 8
 ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length)
 {
-	const BYTE *ip = (const BYTE *)src;
-	BYTE *op = (BYTE *)dst;
-	BYTE *const oend = op + length;
-	do
-		COPY8(op, ip)
-	while (op < oend);
-}
-
-ZSTD_STATIC void ZSTD_wildcopy_e(void *dst, const void *src, void *dstEnd) /* should be faster for decoding, but strangely, not verified on all platform */
-{
-	const BYTE *ip = (const BYTE *)src;
-	BYTE *op = (BYTE *)dst;
-	BYTE *const oend = (BYTE *)dstEnd;
-	do
-		COPY8(op, ip)
-	while (op < oend);
+	if (length > 0)
+		memcpy(dst, src, length);
 }
 
 /*-*******************************************