diff options
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 229 |
1 files changed, 162 insertions, 67 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index c1ff31f48..3376901bd 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -22,13 +22,14 @@ * THE SOFTWARE. */ #include "qemu-common.h" -#include "block_int.h" -#include "module.h" +#include "block/block_int.h" +#include "qemu/module.h" #include <zlib.h> -#include "aes.h" +#include "qemu/aes.h" #include "block/qcow2.h" -#include "qemu-error.h" -#include "qerror.h" +#include "qemu/error-report.h" +#include "qapi/qmp/qerror.h" +#include "qapi/qmp/qbool.h" #include "trace.h" /* @@ -222,7 +223,7 @@ static void report_unsupported_feature(BlockDriverState *bs, * updated successfully. Therefore it is not required to check the return * value of this function. */ -static int qcow2_mark_dirty(BlockDriverState *bs) +int qcow2_mark_dirty(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; uint64_t val; @@ -285,12 +286,44 @@ static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, return ret; } -static int qcow2_open(BlockDriverState *bs, int flags) +static QemuOptsList qcow2_runtime_opts = { + .name = "qcow2", + .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), + .desc = { + { + .name = QCOW2_OPT_LAZY_REFCOUNTS, + .type = QEMU_OPT_BOOL, + .help = "Postpone refcount updates", + }, + { + .name = QCOW2_OPT_DISCARD_REQUEST, + .type = QEMU_OPT_BOOL, + .help = "Pass guest discard requests to the layer below", + }, + { + .name = QCOW2_OPT_DISCARD_SNAPSHOT, + .type = QEMU_OPT_BOOL, + .help = "Generate discard requests when snapshot related space " + "is freed", + }, + { + .name = QCOW2_OPT_DISCARD_OTHER, + .type = QEMU_OPT_BOOL, + .help = "Generate discard requests when other clusters are freed", + }, + { /* end of list */ } + }, +}; + +static int qcow2_open(BlockDriverState *bs, QDict *options, int flags) { BDRVQcowState *s = bs->opaque; int len, i, ret = 0; QCowHeader header; + QemuOpts *opts; + Error *local_err = NULL; uint64_t ext_end; + uint64_t l1_vm_state_index; ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); if (ret < 0) { @@ -311,7 +344,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) be32_to_cpus(&header.nb_snapshots); if (header.magic != QCOW_MAGIC) { - ret = -EINVAL; + ret = -EMEDIUMTYPE; goto fail; } if (header.version < 2 || header.version > 3) { @@ -408,7 +441,14 @@ static int qcow2_open(BlockDriverState *bs, int flags) /* read the level 1 table */ s->l1_size = header.l1_size; - s->l1_vm_state_index = size_to_l1(s, header.size); + + l1_vm_state_index = size_to_l1(s, header.size); + if (l1_vm_state_index > INT_MAX) { + ret = -EFBIG; + goto fail; + } + s->l1_vm_state_index = l1_vm_state_index; + /* the L1 table must contain at least enough entries to put header.size bytes */ if (s->l1_size < s->l1_vm_state_index) { @@ -446,6 +486,7 @@ static int qcow2_open(BlockDriverState *bs, int flags) } QLIST_INIT(&s->cluster_allocs); + QTAILQ_INIT(&s->discards); /* read qcow2 extensions */ if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) { @@ -495,6 +536,38 @@ static int qcow2_open(BlockDriverState *bs, int flags) } } + /* Enable lazy_refcounts according to image and command line options */ + opts = qemu_opts_create_nofail(&qcow2_runtime_opts); + qemu_opts_absorb_qdict(opts, options, &local_err); + if (error_is_set(&local_err)) { + qerror_report_err(local_err); + error_free(local_err); + ret = -EINVAL; + goto fail; + } + + s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, + (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); + + s->discard_passthrough[QCOW2_DISCARD_NEVER] = false; + s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; + s->discard_passthrough[QCOW2_DISCARD_REQUEST] = + qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, + flags & BDRV_O_UNMAP); + s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = + qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); + s->discard_passthrough[QCOW2_DISCARD_OTHER] = + qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); + + qemu_opts_del(opts); + + if (s->use_lazy_refcounts && s->qcow_version < 3) { + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Lazy refcounts require " + "a qcow2 image with at least qemu 1.1 compatibility level"); + ret = -EINVAL; + goto fail; + } + #ifdef DEBUG_ALLOC { BdrvCheckResult result = {0}; @@ -584,7 +657,7 @@ static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs, *pnum = 0; } - return (cluster_offset != 0); + return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO); } /* handle reading after the end of the backing file */ @@ -665,10 +738,6 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, break; case QCOW2_CLUSTER_ZERO: - if (s->qcow_version < 3) { - ret = -EIO; - goto fail; - } qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); break; @@ -745,21 +814,6 @@ fail: return ret; } -static void run_dependent_requests(BDRVQcowState *s, QCowL2Meta *m) -{ - /* Take the request off the list of running requests */ - if (m->nb_clusters != 0) { - QLIST_REMOVE(m, next_in_flight); - } - - /* Restart all dependent requests */ - if (!qemu_co_queue_empty(&m->dependent_requests)) { - qemu_co_mutex_unlock(&s->lock); - qemu_co_queue_restart_all(&m->dependent_requests); - qemu_co_mutex_lock(&s->lock); - } -} - static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, int64_t sector_num, int remaining_sectors, @@ -774,15 +828,11 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, QEMUIOVector hd_qiov; uint64_t bytes_done = 0; uint8_t *cluster_data = NULL; - QCowL2Meta l2meta = { - .nb_clusters = 0, - }; + QCowL2Meta *l2meta = NULL; trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num, remaining_sectors); - qemu_co_queue_init(&l2meta.dependent_requests); - qemu_iovec_init(&hd_qiov, qiov->niov); s->cluster_cache_offset = -1; /* disable compressed cache */ @@ -791,6 +841,8 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, while (remaining_sectors != 0) { + l2meta = NULL; + trace_qcow2_writev_start_part(qemu_coroutine_self()); index_in_cluster = sector_num & (s->cluster_sectors - 1); n_end = index_in_cluster + remaining_sectors; @@ -800,17 +852,11 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, } ret = qcow2_alloc_cluster_offset(bs, sector_num << 9, - index_in_cluster, n_end, &cur_nr_sectors, &l2meta); + index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta); if (ret < 0) { goto fail; } - if (l2meta.nb_clusters > 0 && - (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)) { - qcow2_mark_dirty(bs); - } - - cluster_offset = l2meta.cluster_offset; assert((cluster_offset & 511) == 0); qemu_iovec_reset(&hd_qiov); @@ -835,8 +881,8 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, cur_nr_sectors * 512); } - BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); qemu_co_mutex_unlock(&s->lock); + BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); trace_qcow2_writev_data(qemu_coroutine_self(), (cluster_offset >> 9) + index_in_cluster); ret = bdrv_co_writev(bs->file, @@ -847,12 +893,25 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, goto fail; } - ret = qcow2_alloc_cluster_link_l2(bs, &l2meta); - if (ret < 0) { - goto fail; - } + while (l2meta != NULL) { + QCowL2Meta *next; + + ret = qcow2_alloc_cluster_link_l2(bs, l2meta); + if (ret < 0) { + goto fail; + } + + /* Take the request off the list of running requests */ + if (l2meta->nb_clusters != 0) { + QLIST_REMOVE(l2meta, next_in_flight); + } + + qemu_co_queue_restart_all(&l2meta->dependent_requests); - run_dependent_requests(s, &l2meta); + next = l2meta->next; + g_free(l2meta); + l2meta = next; + } remaining_sectors -= cur_nr_sectors; sector_num += cur_nr_sectors; @@ -862,10 +921,21 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, ret = 0; fail: - run_dependent_requests(s, &l2meta); - qemu_co_mutex_unlock(&s->lock); + while (l2meta != NULL) { + QCowL2Meta *next; + + if (l2meta->nb_clusters != 0) { + QLIST_REMOVE(l2meta, next_in_flight); + } + qemu_co_queue_restart_all(&l2meta->dependent_requests); + + next = l2meta->next; + g_free(l2meta); + l2meta = next; + } + qemu_iovec_destroy(&hd_qiov); qemu_vfree(cluster_data); trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); @@ -902,6 +972,7 @@ static void qcow2_invalidate_cache(BlockDriverState *bs) AES_KEY aes_encrypt_key; AES_KEY aes_decrypt_key; uint32_t crypt_method = 0; + QDict *options; /* * Backing files are read-only which makes all of their metadata immutable, @@ -916,8 +987,14 @@ static void qcow2_invalidate_cache(BlockDriverState *bs) qcow2_close(bs); + options = qdict_new(); + qdict_put(options, QCOW2_OPT_LAZY_REFCOUNTS, + qbool_from_int(s->use_lazy_refcounts)); + memset(s, 0, sizeof(BDRVQcowState)); - qcow2_open(bs, flags); + qcow2_open(bs, options, flags); + + QDECREF(options); if (crypt_method) { s->crypt_method = crypt_method; @@ -1128,31 +1205,34 @@ static int preallocate(BlockDriverState *bs) { uint64_t nb_sectors; uint64_t offset; + uint64_t host_offset = 0; int num; int ret; - QCowL2Meta meta; + QCowL2Meta *meta; nb_sectors = bdrv_getlength(bs) >> 9; offset = 0; - qemu_co_queue_init(&meta.dependent_requests); - meta.cluster_offset = 0; while (nb_sectors) { num = MIN(nb_sectors, INT_MAX >> 9); - ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta); + ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, + &host_offset, &meta); if (ret < 0) { return ret; } - ret = qcow2_alloc_cluster_link_l2(bs, &meta); + ret = qcow2_alloc_cluster_link_l2(bs, meta); if (ret < 0) { - qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters); + qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters, + QCOW2_DISCARD_NEVER); return ret; } /* There are no dependent requests, but we need to remove our request * from the list of in-flight requests */ - run_dependent_requests(bs->opaque, &meta); + if (meta != NULL) { + QLIST_REMOVE(meta, next_in_flight); + } /* TODO Preallocate data if requested */ @@ -1165,10 +1245,10 @@ static int preallocate(BlockDriverState *bs) * all of the allocated clusters (otherwise we get failing reads after * EOF). Extend the image to the last allocated sector. */ - if (meta.cluster_offset != 0) { + if (host_offset != 0) { uint8_t buf[512]; memset(buf, 0, 512); - ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1); + ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1); if (ret < 0) { return ret; } @@ -1216,7 +1296,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, return ret; } - ret = bdrv_file_open(&bs, filename, BDRV_O_RDWR); + ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR); if (ret < 0) { return ret; } @@ -1268,7 +1348,7 @@ static int qcow2_create2(const char *filename, int64_t total_size, */ BlockDriver* drv = bdrv_find_format("qcow2"); assert(drv != NULL); - ret = bdrv_open(bs, filename, + ret = bdrv_open(bs, filename, NULL, BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, drv); if (ret < 0) { goto out; @@ -1436,7 +1516,8 @@ static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, static int qcow2_truncate(BlockDriverState *bs, int64_t offset) { BDRVQcowState *s = bs->opaque; - int ret, new_l1_size; + int64_t new_l1_size; + int ret; if (offset & 511) { error_report("The new size must be a multiple of 512"); @@ -1493,8 +1574,21 @@ static int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, return 0; } - if (nb_sectors != s->cluster_sectors) - return -EINVAL; + if (nb_sectors != s->cluster_sectors) { + ret = -EINVAL; + + /* Zero-pad last write if image size is not cluster aligned */ + if (sector_num + nb_sectors == bs->total_sectors && + nb_sectors < s->cluster_sectors) { + uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); + memset(pad_buf, 0, s->cluster_size); + memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); + ret = qcow2_write_compressed(bs, sector_num, + pad_buf, s->cluster_sectors); + qemu_vfree(pad_buf); + } + return ret; + } out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); @@ -1608,8 +1702,8 @@ static void dump_refcounts(BlockDriverState *bs) } #endif -static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf, - int64_t pos, int size) +static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, + int64_t pos) { BDRVQcowState *s = bs->opaque; int growable = bs->growable; @@ -1617,7 +1711,7 @@ static int qcow2_save_vmstate(BlockDriverState *bs, const uint8_t *buf, BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); bs->growable = 1; - ret = bdrv_pwrite(bs, qcow2_vm_state_offset(s) + pos, buf, size); + ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); bs->growable = growable; return ret; @@ -1691,6 +1785,7 @@ static BlockDriver bdrv_qcow2 = { .bdrv_close = qcow2_close, .bdrv_reopen_prepare = qcow2_reopen_prepare, .bdrv_create = qcow2_create, + .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_co_is_allocated = qcow2_co_is_allocated, .bdrv_set_key = qcow2_set_key, .bdrv_make_empty = qcow2_make_empty, |