From patchwork Wed Feb 6 12:31:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC, V6, 19/33] block: Add qcow2_dedup format and image creation code. From: =?utf-8?q?Beno=C3=AEt_Canet?= X-Patchwork-Id: 218623 Message-Id: <1360153926-9492-20-git-send-email-benoit@irqsave.net> To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com Date: Wed, 6 Feb 2013 13:31:52 +0100 Signed-off-by: Benoit Canet --- block/qcow2.c | 188 +++++++++++++++++++++++++++++++++++++++++---- block/qcow2.h | 2 + include/block/block_int.h | 1 + 3 files changed, 178 insertions(+), 13 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index ad202fa..9cbb2f0 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -277,6 +277,11 @@ int qcow2_mark_dirty(BlockDriverState *bs) return qcow2_add_feature(bs, QCOW2_INCOMPAT_DIRTY); } +static int qcow2_activate_dedup(BlockDriverState *bs) +{ + return qcow2_add_feature(bs, QCOW2_INCOMPAT_DEDUP); +} + /* * Clears an incompatible feature bit and flushes before if necessary. * Only call this function when there are no pending requests, it does not @@ -1267,7 +1272,8 @@ static int preallocate(BlockDriverState *bs) 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, int prealloc, - QEMUOptionParameter *options, int version) + QEMUOptionParameter *options, int version, + bool dedup, uint8_t hash_algo) { /* Calculate cluster_bits */ int cluster_bits; @@ -1294,8 +1300,10 @@ static int qcow2_create2(const char *filename, int64_t total_size, * size for any qcow2 image. */ BlockDriverState* bs; + BDRVQcowState *s; QCowHeader header; - uint8_t* refcount_table; + uint8_t *tables; + int size; int ret; ret = bdrv_create_file(filename, options); @@ -1337,10 +1345,11 @@ static int qcow2_create2(const char *filename, int64_t total_size, goto out; } - /* Write an empty refcount table */ - refcount_table = g_malloc0(cluster_size); - ret = bdrv_pwrite(bs, cluster_size, refcount_table, cluster_size); - g_free(refcount_table); + /* Write an empty refcount table + extra space for dedup table if needed */ + size = dedup ? 2 : 1; + tables = g_malloc0(size * cluster_size); + ret = bdrv_pwrite(bs, cluster_size, tables, size * cluster_size); + g_free(tables); if (ret < 0) { goto out; @@ -1351,7 +1360,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, /* * And now open the image and make it consistent first (i.e. increase the * refcount of the cluster that is occupied by the header and the refcount - * table) + * table and the eventual dedup table) */ BlockDriver* drv = bdrv_find_format("qcow2"); assert(drv != NULL); @@ -1361,7 +1370,8 @@ static int qcow2_create2(const char *filename, int64_t total_size, goto out; } - ret = qcow2_alloc_clusters(bs, 2 * cluster_size); + size++; /* Add a cluster for the header */ + ret = qcow2_alloc_clusters(bs, size * cluster_size); if (ret < 0) { goto out; @@ -1371,11 +1381,29 @@ static int qcow2_create2(const char *filename, int64_t total_size, } /* Okay, now that we have a valid image, let's give it the right size */ + s = bs->opaque; ret = bdrv_truncate(bs, total_size * BDRV_SECTOR_SIZE); if (ret < 0) { goto out; } + if (dedup) { + s->has_dedup = true; + s->dedup_table_offset = cluster_size * 2; + s->dedup_table_size = cluster_size / sizeof(uint64_t); + s->dedup_hash_algo = hash_algo; + + ret = qcow2_activate_dedup(bs); + if (ret < 0) { + goto out; + } + + ret = qcow2_update_header(bs); + if (ret < 0) { + goto out; + } + } + /* Want a backing file? There you go.*/ if (backing_file) { ret = bdrv_change_backing_file(bs, backing_file, backing_format); @@ -1401,15 +1429,41 @@ out: return ret; } +static int qcow2_warn_if_version_3_is_needed(int version, + bool has_feature, + const char *feature) +{ + if (version < 3 && has_feature) { + fprintf(stderr, "%s only supported with compatibility " + "level 1.1 and above (use compat=1.1 or greater)\n", + feature); + return -EINVAL; + } + return 0; +} + +static int8_t qcow2_get_dedup_hash_algo(char *value) +{ + if (!value || !strcmp(value, "sha256")) { + return QCOW_HASH_SHA256; + } + + error_printf("Unsupported deduplication hash algorithm.\n"); + return -EINVAL; +} + static int qcow2_create(const char *filename, QEMUOptionParameter *options) { const char *backing_file = NULL; const char *backing_fmt = NULL; uint64_t sectors = 0; int flags = 0; + int ret; size_t cluster_size = DEFAULT_CLUSTER_SIZE; int prealloc = 0; int version = 2; + bool dedup = false; + int8_t hash_algo = 0; /* Read out options */ while (options && options->name) { @@ -1447,24 +1501,42 @@ static int qcow2_create(const char *filename, QEMUOptionParameter *options) } } else if (!strcmp(options->name, BLOCK_OPT_LAZY_REFCOUNTS)) { flags |= options->value.n ? BLOCK_FLAG_LAZY_REFCOUNTS : 0; + } else if (!strcmp(options->name, BLOCK_OPT_DEDUP)) { + hash_algo = qcow2_get_dedup_hash_algo(options->value.s); + if (hash_algo < 0) { + return hash_algo; + } + dedup = true; } options++; } + if (dedup) { + version = 3; + } + if (backing_file && prealloc) { fprintf(stderr, "Backing file and preallocation cannot be used at " "the same time\n"); return -EINVAL; } - if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) { - fprintf(stderr, "Lazy refcounts only supported with compatibility " - "level 1.1 and above (use compat=1.1 or greater)\n"); - return -EINVAL; + ret = qcow2_warn_if_version_3_is_needed(version, + flags & BLOCK_FLAG_LAZY_REFCOUNTS, + "Lazy refcounts"); + if (ret < 0) { + return ret; + } + ret = qcow2_warn_if_version_3_is_needed(version, + dedup, + "Deduplication"); + if (ret < 0) { + return ret; } return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags, - cluster_size, prealloc, options, version); + cluster_size, prealloc, options, version, + dedup, hash_algo); } static int qcow2_make_empty(BlockDriverState *bs) @@ -1770,6 +1842,56 @@ static QEMUOptionParameter qcow2_create_options[] = { { NULL } }; +static QEMUOptionParameter qcow2_dedup_create_options[] = { + { + .name = BLOCK_OPT_SIZE, + .type = OPT_SIZE, + .help = "Virtual disk size" + }, + { + .name = BLOCK_OPT_COMPAT_LEVEL, + .type = OPT_STRING, + .help = "Compatibility level (0.10 or 1.1)", + }, + { + .name = BLOCK_OPT_BACKING_FILE, + .type = OPT_STRING, + .help = "File name of a base image" + }, + { + .name = BLOCK_OPT_BACKING_FMT, + .type = OPT_STRING, + .help = "Image format of the base image" + }, + { + .name = BLOCK_OPT_ENCRYPT, + .type = OPT_FLAG, + .help = "Encrypt the image" + }, + { + .name = BLOCK_OPT_CLUSTER_SIZE, + .type = OPT_SIZE, + .help = "qcow2 cluster size", + .value = { .n = DEFAULT_DEDUP_CLUSTER_SIZE }, + }, + { + .name = BLOCK_OPT_PREALLOC, + .type = OPT_STRING, + .help = "Preallocation mode (allowed values: off, metadata)" + }, + { + .name = BLOCK_OPT_LAZY_REFCOUNTS, + .type = OPT_FLAG, + .help = "Postpone refcount updates", + }, + { + .name = BLOCK_OPT_DEDUP, + .type = OPT_STRING, + .help = "Deduplication", + }, + { NULL } +}; + static BlockDriver bdrv_qcow2 = { .format_name = "qcow2", .instance_size = sizeof(BDRVQcowState), @@ -1809,9 +1931,49 @@ static BlockDriver bdrv_qcow2 = { .bdrv_check = qcow2_check, }; +static BlockDriver bdrv_qcow2_dedup = { + .format_name = "qcow2_dedup", + .instance_size = sizeof(BDRVQcowState), + .bdrv_probe = qcow2_probe, + .bdrv_open = qcow2_open, + .bdrv_close = qcow2_close, + .bdrv_reopen_prepare = qcow2_reopen_prepare, + .bdrv_create = qcow2_create, + .bdrv_co_is_allocated = qcow2_co_is_allocated, + .bdrv_set_key = qcow2_set_key, + .bdrv_make_empty = qcow2_make_empty, + + .bdrv_co_readv = qcow2_co_readv, + .bdrv_co_writev = qcow2_co_writev, + .bdrv_co_flush_to_os = qcow2_co_flush_to_os, + + .bdrv_co_write_zeroes = qcow2_co_write_zeroes, + .bdrv_co_discard = qcow2_co_discard, + .bdrv_truncate = qcow2_truncate, + .bdrv_write_compressed = qcow2_write_compressed, + + .bdrv_snapshot_create = qcow2_snapshot_create, + .bdrv_snapshot_goto = qcow2_snapshot_goto, + .bdrv_snapshot_delete = qcow2_snapshot_delete, + .bdrv_snapshot_list = qcow2_snapshot_list, + .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp, + .bdrv_get_info = qcow2_get_info, + + .bdrv_save_vmstate = qcow2_save_vmstate, + .bdrv_load_vmstate = qcow2_load_vmstate, + + .bdrv_change_backing_file = qcow2_change_backing_file, + + .bdrv_invalidate_cache = qcow2_invalidate_cache, + + .create_options = qcow2_dedup_create_options, + .bdrv_check = qcow2_check, +}; + static void bdrv_qcow2_init(void) { bdrv_register(&bdrv_qcow2); + bdrv_register(&bdrv_qcow2_dedup); } block_init(bdrv_qcow2_init); diff --git a/block/qcow2.h b/block/qcow2.h index 77ffa0b..5b51005 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -60,7 +60,9 @@ /* Must be at least 4 to cover all cases of refcount table growth */ #define REFCOUNT_CACHE_SIZE 4 +#define DEDUP_CACHE_SIZE 4 #define DEFAULT_CLUSTER_SIZE 65536 +#define DEFAULT_DEDUP_CLUSTER_SIZE 4096 #define HASH_LENGTH 32 /* indicate that the hash structure is empty and miss offset */ diff --git a/include/block/block_int.h b/include/block/block_int.h index eaad53e..62c72fc 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -57,6 +57,7 @@ #define BLOCK_OPT_COMPAT_LEVEL "compat" #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" +#define BLOCK_OPT_DEDUP "dedup" typedef struct BdrvTrackedRequest BdrvTrackedRequest;