diff options
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c new file mode 100644 index 0000000..502335b --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c @@ -0,0 +1,175 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright 2009 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ +/* + * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. + */ + +/* + * Copyright (c) 2013 by Delphix. All rights reserved. + */ + +#include <sys/zfs_context.h> +#include <sys/compress.h> +#include <sys/kstat.h> +#include <sys/spa.h> +#include <sys/zio.h> +#include <sys/zio_compress.h> + +typedef struct zcomp_stats { + kstat_named_t zcompstat_attempts; + kstat_named_t zcompstat_empty; + kstat_named_t zcompstat_skipped_insufficient_gain; +} zcomp_stats_t; + +static zcomp_stats_t zcomp_stats = { + { "attempts", KSTAT_DATA_UINT64 }, + { "empty", KSTAT_DATA_UINT64 }, + { "skipped_insufficient_gain", KSTAT_DATA_UINT64 } +}; + +#define ZCOMPSTAT_INCR(stat, val) \ + atomic_add_64(&zcomp_stats.stat.value.ui64, (val)); + +#define ZCOMPSTAT_BUMP(stat) ZCOMPSTAT_INCR(stat, 1); + +kstat_t *zcomp_ksp; + +/* + * Compression vectors. + */ + +zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = { + {NULL, NULL, 0, "inherit"}, + {NULL, NULL, 0, "on"}, + {NULL, NULL, 0, "uncompressed"}, + {lzjb_compress, lzjb_decompress, 0, "lzjb"}, + {NULL, NULL, 0, "empty"}, + {gzip_compress, gzip_decompress, 1, "gzip-1"}, + {gzip_compress, gzip_decompress, 2, "gzip-2"}, + {gzip_compress, gzip_decompress, 3, "gzip-3"}, + {gzip_compress, gzip_decompress, 4, "gzip-4"}, + {gzip_compress, gzip_decompress, 5, "gzip-5"}, + {gzip_compress, gzip_decompress, 6, "gzip-6"}, + {gzip_compress, gzip_decompress, 7, "gzip-7"}, + {gzip_compress, gzip_decompress, 8, "gzip-8"}, + {gzip_compress, gzip_decompress, 9, "gzip-9"}, + {zle_compress, zle_decompress, 64, "zle"}, + {lz4_compress, lz4_decompress, 0, "lz4"}, +}; + +enum zio_compress +zio_compress_select(enum zio_compress child, enum zio_compress parent) +{ + ASSERT(child < ZIO_COMPRESS_FUNCTIONS); + ASSERT(parent < ZIO_COMPRESS_FUNCTIONS); + ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON); + + if (child == ZIO_COMPRESS_INHERIT) + return (parent); + + if (child == ZIO_COMPRESS_ON) + return (ZIO_COMPRESS_ON_VALUE); + + return (child); +} + +size_t +zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len, + size_t minblocksize) +{ + uint64_t *word, *word_end; + size_t c_len, d_len; + zio_compress_info_t *ci = &zio_compress_table[c]; + + ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS); + ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL); + + ZCOMPSTAT_BUMP(zcompstat_attempts); + + /* + * If the data is all zeroes, we don't even need to allocate + * a block for it. We indicate this by returning zero size. + */ + word_end = (uint64_t *)((char *)src + s_len); + for (word = src; word < word_end; word++) + if (*word != 0) + break; + + if (word == word_end) { + ZCOMPSTAT_BUMP(zcompstat_empty); + return (0); + } + + if (c == ZIO_COMPRESS_EMPTY) + return (s_len); + + /* Compress at least 12.5% */ + d_len = s_len - (s_len >> 3); + c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level); + + if (c_len > d_len) { + ZCOMPSTAT_BUMP(zcompstat_skipped_insufficient_gain); + return (s_len); + } + + ASSERT3U(c_len, <=, d_len); + return (c_len); +} + +int +zio_decompress_data(enum zio_compress c, void *src, void *dst, + size_t s_len, size_t d_len) +{ + zio_compress_info_t *ci = &zio_compress_table[c]; + + if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL) + return (SET_ERROR(EINVAL)); + + return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level)); +} + +void +zio_compress_init(void) +{ + + zcomp_ksp = kstat_create("zfs", 0, "zcompstats", "misc", + KSTAT_TYPE_NAMED, sizeof (zcomp_stats) / sizeof (kstat_named_t), + KSTAT_FLAG_VIRTUAL); + + if (zcomp_ksp != NULL) { + zcomp_ksp->ks_data = &zcomp_stats; + kstat_install(zcomp_ksp); + } +} + +void +zio_compress_fini(void) +{ + if (zcomp_ksp != NULL) { + kstat_delete(zcomp_ksp); + zcomp_ksp = NULL; + } +} |
