Add zstd support to zfs

This PR adds two new compression types, based on ZStandard:

- zstd: A basic ZStandard compression algorithm Available compression.
  Levels for zstd are zstd-1 through zstd-19, where the compression
  increases with every level, but speed decreases.

- zstd-fast: A faster version of the ZStandard compression algorithm
  zstd-fast is basically a "negative" level of zstd. The compression
  decreases with every level, but speed increases.

  Available compression levels for zstd-fast:
   - zstd-fast-1 through zstd-fast-10
   - zstd-fast-20 through zstd-fast-100 (in increments of 10)
   - zstd-fast-500 and zstd-fast-1000

For more information check the man page.

Implementation details:

Rather than treat each level of zstd as a different algorithm (as was
done historically with gzip), the block pointer `enum zio_compress`
value is simply zstd for all levels, including zstd-fast, since they all
use the same decompression function.

The compress= property (a 64bit unsigned integer) uses the lower 7 bits
to store the compression algorithm (matching the number of bits used in
a block pointer, as the 8th bit was borrowed for embedded block
pointers).  The upper bits are used to store the compression level.

It is necessary to be able to determine what compression level was used
when later reading a block back, so the concept used in LZ4, where the
first 32bits of the on-disk value are the size of the compressed data
(since the allocation is rounded up to the nearest ashift), was
extended, and we store the version of ZSTD and the level as well as the
compressed size. This value is returned when decompressing a block, so
that if the block needs to be recompressed (L2ARC, nop-write, etc), that
the same parameters will be used to result in the matching checksum.

All of the internal ZFS code ( `arc_buf_hdr_t`, `objset_t`,
`zio_prop_t`, etc.) uses the separated _compress and _complevel
variables.  Only the properties ZAP contains the combined/bit-shifted
value. The combined value is split when the compression_changed_cb()
callback is called, and sets both objset members (os_compress and
os_complevel).

The userspace tools all use the combined/bit-shifted value.

Additional notes:

zdb can now also decode the ZSTD compression header (flag -Z) and
inspect the size, version and compression level saved in that header.
For each record, if it is ZSTD compressed, the parameters of the decoded
compression header get printed.

ZSTD is included with all current tests and new tests are added
as-needed.

Per-dataset feature flags now get activated when the property is set.
If a compression algorithm requires a feature flag, zfs activates the
feature when the property is set, rather than waiting for the first
block to be born.  This is currently only used by zstd but can be
extended as needed.

Portions-Sponsored-By: The FreeBSD Foundation
Co-authored-by: Allan Jude <[email protected]>
Co-authored-by: Brian Behlendorf <[email protected]>
Co-authored-by: Sebastian Gottschall <[email protected]>
Co-authored-by: Kjeld Schouten-Lebbing <[email protected]>
Co-authored-by: Michael Niewöhner <[email protected]>
Signed-off-by: Allan Jude <[email protected]>
Signed-off-by: Allan Jude <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Sebastian Gottschall <[email protected]>
Signed-off-by: Kjeld Schouten-Lebbing <[email protected]>
Signed-off-by: Michael Niewöhner <[email protected]>
Closes #6247
Closes #9024
Closes #10277
Closes #10278

1 files changed, 78 insertions, 3 deletions

diff --git a/include/sys/zio_compress.h b/include/sys/zio_compress.h
index 208117eee..4a22ad2a2 100644
--- a/include/sys/zio_compress.h
+++ b/include/sys/zio_compress.h
@@ -21,6 +21,8 @@
 
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright (c) 2019, Allan Jude
+ * Copyright (c) 2019, Klara Inc.
  * Use is subject to license terms.
  * Copyright (c) 2015, 2016 by Delphix. All rights reserved.
  */
@@ -51,15 +53,86 @@ enum zio_compress {
 	ZIO_COMPRESS_GZIP_9,
 	ZIO_COMPRESS_ZLE,
 	ZIO_COMPRESS_LZ4,
+	ZIO_COMPRESS_ZSTD,
 	ZIO_COMPRESS_FUNCTIONS
 };
 
+/* Compression algorithms that have levels */
+#define	ZIO_COMPRESS_HASLEVEL(compress)	((compress == ZIO_COMPRESS_ZSTD || \
+					(compress >= ZIO_COMPRESS_GZIP_1 && \
+					compress <= ZIO_COMPRESS_GZIP_9)))
+
+#define	ZIO_COMPLEVEL_INHERIT	0
+#define	ZIO_COMPLEVEL_DEFAULT	255
+
+enum zio_zstd_levels {
+	ZIO_ZSTD_LEVEL_INHERIT = 0,
+	ZIO_ZSTD_LEVEL_1,
+#define	ZIO_ZSTD_LEVEL_MIN	ZIO_ZSTD_LEVEL_1
+	ZIO_ZSTD_LEVEL_2,
+	ZIO_ZSTD_LEVEL_3,
+#define	ZIO_ZSTD_LEVEL_DEFAULT	ZIO_ZSTD_LEVEL_3
+	ZIO_ZSTD_LEVEL_4,
+	ZIO_ZSTD_LEVEL_5,
+	ZIO_ZSTD_LEVEL_6,
+	ZIO_ZSTD_LEVEL_7,
+	ZIO_ZSTD_LEVEL_8,
+	ZIO_ZSTD_LEVEL_9,
+	ZIO_ZSTD_LEVEL_10,
+	ZIO_ZSTD_LEVEL_11,
+	ZIO_ZSTD_LEVEL_12,
+	ZIO_ZSTD_LEVEL_13,
+	ZIO_ZSTD_LEVEL_14,
+	ZIO_ZSTD_LEVEL_15,
+	ZIO_ZSTD_LEVEL_16,
+	ZIO_ZSTD_LEVEL_17,
+	ZIO_ZSTD_LEVEL_18,
+	ZIO_ZSTD_LEVEL_19,
+#define	ZIO_ZSTD_LEVEL_MAX	ZIO_ZSTD_LEVEL_19
+	ZIO_ZSTD_LEVEL_RESERVE = 101, /* Leave room for new positive levels */
+	ZIO_ZSTD_LEVEL_FAST, /* Fast levels are negative */
+	ZIO_ZSTD_LEVEL_FAST_1,
+#define	ZIO_ZSTD_LEVEL_FAST_DEFAULT	ZIO_ZSTD_LEVEL_FAST_1
+	ZIO_ZSTD_LEVEL_FAST_2,
+	ZIO_ZSTD_LEVEL_FAST_3,
+	ZIO_ZSTD_LEVEL_FAST_4,
+	ZIO_ZSTD_LEVEL_FAST_5,
+	ZIO_ZSTD_LEVEL_FAST_6,
+	ZIO_ZSTD_LEVEL_FAST_7,
+	ZIO_ZSTD_LEVEL_FAST_8,
+	ZIO_ZSTD_LEVEL_FAST_9,
+	ZIO_ZSTD_LEVEL_FAST_10,
+	ZIO_ZSTD_LEVEL_FAST_20,
+	ZIO_ZSTD_LEVEL_FAST_30,
+	ZIO_ZSTD_LEVEL_FAST_40,
+	ZIO_ZSTD_LEVEL_FAST_50,
+	ZIO_ZSTD_LEVEL_FAST_60,
+	ZIO_ZSTD_LEVEL_FAST_70,
+	ZIO_ZSTD_LEVEL_FAST_80,
+	ZIO_ZSTD_LEVEL_FAST_90,
+	ZIO_ZSTD_LEVEL_FAST_100,
+	ZIO_ZSTD_LEVEL_FAST_500,
+	ZIO_ZSTD_LEVEL_FAST_1000,
+#define	ZIO_ZSTD_LEVEL_FAST_MAX	ZIO_ZSTD_LEVEL_FAST_1000
+	ZIO_ZSTD_LEVEL_AUTO = 251, /* Reserved for future use */
+	ZIO_ZSTD_LEVEL_LEVELS
+};
+
+/* Forward Declaration to avoid visibility problems */
+struct zio_prop;
+
 /* Common signature for all zio compress functions. */
 typedef size_t zio_compress_func_t(void *src, void *dst,
     size_t s_len, size_t d_len, int);
 /* Common signature for all zio decompress functions. */
 typedef int zio_decompress_func_t(void *src, void *dst,
     size_t s_len, size_t d_len, int);
+/* Common signature for all zio decompress and get level functions. */
+typedef int zio_decompresslevel_func_t(void *src, void *dst,
+    size_t s_len, size_t d_len, uint8_t *level);
+/* Common signature for all zio get-compression-level functions. */
+typedef int zio_getlevel_func_t(void *src, size_t s_len, uint8_t *level);
+
 
 /*
  * Common signature for all zio decompress functions using an ABD as input.
@@ -76,6 +149,7 @@ typedef const struct zio_compress_info {
 	int				ci_level;
 	zio_compress_func_t		*ci_compress;
 	zio_decompress_func_t		*ci_decompress;
+	zio_decompresslevel_func_t	*ci_decompress_level;
 } zio_compress_info_t;
 
 extern zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS];
@@ -110,11 +184,12 @@ extern int lz4_decompress_zfs(void *src, void *dst, size_t s_len, size_t d_len,
  * Compress and decompress data if necessary.
  */
 extern size_t zio_compress_data(enum zio_compress c, abd_t *src, void *dst,
-    size_t s_len);
+    size_t s_len, uint8_t level);
 extern int zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
-    size_t s_len, size_t d_len);
+    size_t s_len, size_t d_len, uint8_t *level);
 extern int zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
-    size_t s_len, size_t d_len);
+    size_t s_len, size_t d_len, uint8_t *level);
+extern int zio_compress_to_feature(enum zio_compress comp);
 
 #ifdef	__cplusplus
 }