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-rw-r--r--uts/common/fs/zfs/zio_compress.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/zio_compress.c b/uts/common/fs/zfs/zio_compress.c
new file mode 100644
index 000000000000..f148977c4468
--- /dev/null
+++ b/uts/common/fs/zfs/zio_compress.c
@@ -0,0 +1,132 @@
+/*
+ * 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.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/compress.h>
+#include <sys/spa.h>
+#include <sys/zio.h>
+#include <sys/zio_compress.h>
+
+/*
+ * 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"},
+};
+
+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)
+{
+ uint64_t *word, *word_end;
+ size_t c_len, d_len, r_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);
+
+ /*
+ * 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)
+ return (0);
+
+ if (c == ZIO_COMPRESS_EMPTY)
+ return (s_len);
+
+ /* Compress at least 12.5% */
+ d_len = P2ALIGN(s_len - (s_len >> 3), (size_t)SPA_MINBLOCKSIZE);
+ if (d_len == 0)
+ return (s_len);
+
+ c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
+
+ if (c_len > d_len)
+ return (s_len);
+
+ /*
+ * Cool. We compressed at least as much as we were hoping to.
+ * For both security and repeatability, pad out the last sector.
+ */
+ r_len = P2ROUNDUP(c_len, (size_t)SPA_MINBLOCKSIZE);
+ if (r_len > c_len) {
+ bzero((char *)dst + c_len, r_len - c_len);
+ c_len = r_len;
+ }
+
+ ASSERT3U(c_len, <=, d_len);
+ ASSERT(P2PHASE(c_len, (size_t)SPA_MINBLOCKSIZE) == 0);
+
+ 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 (EINVAL);
+
+ return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
+}