[1/4] block/qcow2: add compression_algorithm create option

Message ID	1498566850-7934-2-git-send-email-pl@kamp.de (mailing list archive)
State	New, archived
Headers	show Return-Path: <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> avast: 1.2.2/17010300. spamassassin: 3.4.1. Clear:RC:1(195.62.97.28):. Processed in 0.364339 secs); 27 Jun 2017 12:34:24 -0000 From: Peter Lieven <pl@kamp.de> To: qemu-block@nongnu.org Date: Tue, 27 Jun 2017 14:34:07 +0200 Message-Id: <1498566850-7934-2-git-send-email-pl@kamp.de> In-Reply-To: <1498566850-7934-1-git-send-email-pl@kamp.de> References: <1498566850-7934-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCH 1/4] block/qcow2: add compression_algorithm create option Precedence: list Cc: kwolf@redhat.com, Peter Lieven <pl@kamp.de>, qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org, lersek@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org>

diff --git a/block/qcow2.c b/block/qcow2.c index 2f94f03..893b145 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -60,9 +60,11 @@ typedef struct { uint32_t len; } QEMU_PACKED QCowExtension; -#define QCOW2_EXT_MAGIC_END 0 -#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA -#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 +#define QCOW2_EXT_MAGIC_END 0 +#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA +#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 +#define QCOW2_EXT_MAGIC_COMPRESSION_ALGORITHM 0xc0318300 +/* 0xc03183xx reserved for further use of compression algorithm parameters */ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) { @@ -76,6 +78,15 @@ static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) return 0; } +static uint32_t is_compression_algorithm_supported(char *algorithm) +{ + if (!algorithm[0] || !strcmp(algorithm, "zlib")) { + /* no algorithm means the old default of zlib compression + * with 12 window bits */ + return QCOW2_COMPRESSION_ZLIB; + } + return 0; +} /* * read qcow2 extension and fill bs @@ -148,6 +159,34 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, #endif break; + case QCOW2_EXT_MAGIC_COMPRESSION_ALGORITHM: + if (ext.len >= sizeof(s->compression_algorithm)) { + error_setg(errp, "ERROR: ext_compression_algorithm: len=%" + PRIu32 " too large (>=%zu)", ext.len, + sizeof(s->compression_algorithm)); + return 2; + } + ret = bdrv_pread(bs->file, offset, s->compression_algorithm, + ext.len); + if (ret < 0) { + error_setg_errno(errp, -ret, "ERROR: ext_compression_algorithm:" + " Could not read algorithm name"); + return 3; + } + s->compression_algorithm[ext.len] = '\0'; + s->compression_algorithm_id = + is_compression_algorithm_supported(s->compression_algorithm); + if (!s->compression_algorithm_id) { + error_setg(errp, "ERROR: compression algorithm '%s' is " + " unsupported", s->compression_algorithm); + return 4; + } +#ifdef DEBUG_EXT + printf("Qcow2: Got compression algorithm %s\n", + s->compression_algorithm); +#endif + break; + case QCOW2_EXT_MAGIC_FEATURE_TABLE: if (p_feature_table != NULL) { void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); @@ -1104,6 +1143,7 @@ static int qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, s->cluster_cache_offset = -1; s->flags = flags; + s->compression_algorithm_id = QCOW2_COMPRESSION_ZLIB; ret = qcow2_refcount_init(bs); if (ret != 0) { @@ -1981,6 +2021,21 @@ int qcow2_update_header(BlockDriverState *bs) buflen -= ret; } + /* Compression Algorithm header extension */ + if (s->compression_algorithm[0]) { + ret = header_ext_add(buf, QCOW2_EXT_MAGIC_COMPRESSION_ALGORITHM, + s->compression_algorithm, + strlen(s->compression_algorithm), + buflen); + if (ret < 0) { + goto fail; + } + buf += ret; + buflen -= ret; + header->incompatible_features |= + cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION); + } + /* Feature table */ if (s->qcow_version >= 3) { Qcow2Feature features[] = { @@ -1995,6 +2050,11 @@ int qcow2_update_header(BlockDriverState *bs) .name = "corrupt bit", }, { + .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, + .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR, + .name = "compression algorithm", + }, + { .type = QCOW2_FEAT_TYPE_COMPATIBLE, .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, .name = "lazy refcounts", @@ -2144,7 +2204,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, const char *backing_file, const char *backing_format, int flags, size_t cluster_size, PreallocMode prealloc, QemuOpts *opts, int version, int refcount_order, - Error **errp) + char *compression_algorithm, Error **errp) { int cluster_bits; QDict *options; @@ -2332,6 +2392,12 @@ static int qcow2_create2(const char *filename, int64_t total_size, abort(); } + if (compression_algorithm[0]) { + BDRVQcow2State *s = blk_bs(blk)->opaque; + memcpy(s->compression_algorithm, compression_algorithm, + strlen(compression_algorithm)); + } + /* Create a full header (including things like feature table) */ ret = qcow2_update_header(blk_bs(blk)); if (ret < 0) { @@ -2395,6 +2461,7 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp) char *backing_file = NULL; char *backing_fmt = NULL; char *buf = NULL; + char *compression_algorithm = NULL; uint64_t size = 0; int flags = 0; size_t cluster_size = DEFAULT_CLUSTER_SIZE; @@ -2475,15 +2542,25 @@ static int qcow2_create(const char *filename, QemuOpts *opts, Error **errp) refcount_order = ctz32(refcount_bits); + compression_algorithm = qemu_opt_get_del(opts, + BLOCK_OPT_COMPRESSION_ALGORITHM); + if (!is_compression_algorithm_supported(compression_algorithm)) { + error_setg(errp, "Compression algorithm '%s' is not supported", + compression_algorithm); + ret = -EINVAL; + goto finish; + } + ret = qcow2_create2(filename, size, backing_file, backing_fmt, flags, cluster_size, prealloc, opts, version, refcount_order, - &local_err); + compression_algorithm, &local_err); error_propagate(errp, local_err); finish: g_free(backing_file); g_free(backing_fmt); g_free(buf); + g_free(compression_algorithm); return ret; } @@ -3458,6 +3535,12 @@ static QemuOptsList qcow2_create_opts = { .help = "Width of a reference count entry in bits", .def_value_str = "16" }, + { + .name = BLOCK_OPT_COMPRESSION_ALGORITHM, + .type = QEMU_OPT_STRING, + .help = "Compression algorithm used for compressed clusters", + .def_value_str = "" + }, { /* end of list */ } } }; diff --git a/block/qcow2.h b/block/qcow2.h index 87b15eb..1c9ba06 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -171,6 +171,10 @@ typedef struct Qcow2UnknownHeaderExtension { } Qcow2UnknownHeaderExtension; enum { + QCOW2_COMPRESSION_ZLIB = 0xC0318301, +}; + +enum { QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, QCOW2_FEAT_TYPE_COMPATIBLE = 1, QCOW2_FEAT_TYPE_AUTOCLEAR = 2, @@ -178,13 +182,16 @@ enum { /* Incompatible feature bits */ enum { - QCOW2_INCOMPAT_DIRTY_BITNR = 0, - QCOW2_INCOMPAT_CORRUPT_BITNR = 1, - QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, - QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, + QCOW2_INCOMPAT_DIRTY_BITNR = 0, + QCOW2_INCOMPAT_CORRUPT_BITNR = 1, + QCOW2_INCOMPAT_COMPRESSION_BITNR = 2, + QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, + QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, + QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR, QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY - | QCOW2_INCOMPAT_CORRUPT, + | QCOW2_INCOMPAT_CORRUPT + | QCOW2_INCOMPAT_COMPRESSION, }; /* Compatible feature bits */ @@ -294,6 +301,9 @@ typedef struct BDRVQcow2State { * override) */ char *image_backing_file; char *image_backing_format; + + char compression_algorithm[16]; + uint32_t compression_algorithm_id; } BDRVQcow2State; typedef struct Qcow2COWRegion { diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt index 80cdfd0..1f165d6 100644 --- a/docs/interop/qcow2.txt +++ b/docs/interop/qcow2.txt @@ -85,7 +85,11 @@ in the description of a field. be written to (unless for regaining consistency). - Bits 2-63: Reserved (set to 0) + Bit 2: Compress algorithm bit. If this bit is set then + the compress algorithm extension must be parsed + and checked for compatiblity. + + Bits 3-63: Reserved (set to 0) 80 - 87: compatible_features Bitmask of compatible features. An implementation can @@ -135,6 +139,8 @@ be stored. Each extension has a structure like the following: 0xE2792ACA - Backing file format name 0x6803f857 - Feature name table 0x23852875 - Bitmaps extension + 0xC0318300 - Compression Algorithm + 0xC03183xx - Reserved for compression algorithm params other - Unknown header extension, can be safely ignored diff --git a/include/block/block_int.h b/include/block/block_int.h index 15fa602..03a4b8f 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -40,23 +40,24 @@ #define BLOCK_FLAG_ENCRYPT 1 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 -#define BLOCK_OPT_SIZE "size" -#define BLOCK_OPT_ENCRYPT "encryption" -#define BLOCK_OPT_COMPAT6 "compat6" -#define BLOCK_OPT_HWVERSION "hwversion" -#define BLOCK_OPT_BACKING_FILE "backing_file" -#define BLOCK_OPT_BACKING_FMT "backing_fmt" -#define BLOCK_OPT_CLUSTER_SIZE "cluster_size" -#define BLOCK_OPT_TABLE_SIZE "table_size" -#define BLOCK_OPT_PREALLOC "preallocation" -#define BLOCK_OPT_SUBFMT "subformat" -#define BLOCK_OPT_COMPAT_LEVEL "compat" -#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" -#define BLOCK_OPT_ADAPTER_TYPE "adapter_type" -#define BLOCK_OPT_REDUNDANCY "redundancy" -#define BLOCK_OPT_NOCOW "nocow" -#define BLOCK_OPT_OBJECT_SIZE "object_size" -#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits" +#define BLOCK_OPT_SIZE "size" +#define BLOCK_OPT_ENCRYPT "encryption" +#define BLOCK_OPT_COMPAT6 "compat6" +#define BLOCK_OPT_HWVERSION "hwversion" +#define BLOCK_OPT_BACKING_FILE "backing_file" +#define BLOCK_OPT_BACKING_FMT "backing_fmt" +#define BLOCK_OPT_CLUSTER_SIZE "cluster_size" +#define BLOCK_OPT_TABLE_SIZE "table_size" +#define BLOCK_OPT_PREALLOC "preallocation" +#define BLOCK_OPT_SUBFMT "subformat" +#define BLOCK_OPT_COMPAT_LEVEL "compat" +#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" +#define BLOCK_OPT_ADAPTER_TYPE "adapter_type" +#define BLOCK_OPT_REDUNDANCY "redundancy" +#define BLOCK_OPT_NOCOW "nocow" +#define BLOCK_OPT_OBJECT_SIZE "object_size" +#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits" +#define BLOCK_OPT_COMPRESSION_ALGORITHM "compression_algorithm" #define BLOCK_PROBE_BUF_SIZE 512 diff --git a/qemu-img.texi b/qemu-img.texi index 5b925ec..c0d1bec 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -621,6 +621,16 @@ file which is COW and has data blocks already, it couldn't be changed to NOCOW by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if the NOCOW flag is set or not (Capital 'C' is NOCOW flag). +@item compression_algorithm +Defines which compression algorithm is should be used for compressed clusters. +The following options are available if support for the respective libraries +has been enabled at compile time: + + zlib Uses standard zlib compression (default) + +The compression algorithm can only be defined at image create time and cannot +be changed later. + @end table @item Other

[1/4] block/qcow2: add compression_algorithm create option

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