* 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"
/*
Differences with QCOW:
uint32_t magic;
uint32_t len;
} QCowExtension;
+
#define QCOW2_EXT_MAGIC_END 0
#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
+#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
{
if (buf_size >= sizeof(QCowHeader) &&
be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
- be32_to_cpu(cow_header->version) >= QCOW_VERSION)
+ be32_to_cpu(cow_header->version) >= 2)
return 100;
else
return 0;
* return 0 upon success, non-0 otherwise
*/
static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
- uint64_t end_offset)
+ uint64_t end_offset, void **p_feature_table)
{
+ BDRVQcowState *s = bs->opaque;
QCowExtension ext;
uint64_t offset;
+ int ret;
#ifdef DEBUG_EXT
printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
while (offset < end_offset) {
#ifdef DEBUG_EXT
- BDRVQcowState *s = bs->opaque;
/* Sanity check */
if (offset > s->cluster_size)
printf("qcow2_read_extension: suspicious offset %lu\n", offset);
#ifdef DEBUG_EXT
printf("ext.magic = 0x%x\n", ext.magic);
#endif
+ if (ext.len > end_offset - offset) {
+ error_report("Header extension too large");
+ return -EINVAL;
+ }
+
switch (ext.magic) {
case QCOW2_EXT_MAGIC_END:
return 0;
#ifdef DEBUG_EXT
printf("Qcow2: Got format extension %s\n", bs->backing_format);
#endif
- offset = ((offset + ext.len + 7) & ~7);
+ break;
+
+ case QCOW2_EXT_MAGIC_FEATURE_TABLE:
+ if (p_feature_table != NULL) {
+ void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature));
+ ret = bdrv_pread(bs->file, offset , feature_table, ext.len);
+ if (ret < 0) {
+ return ret;
+ }
+
+ *p_feature_table = feature_table;
+ }
break;
default:
- /* unknown magic -- just skip it */
- offset = ((offset + ext.len + 7) & ~7);
+ /* unknown magic - save it in case we need to rewrite the header */
+ {
+ Qcow2UnknownHeaderExtension *uext;
+
+ uext = g_malloc0(sizeof(*uext) + ext.len);
+ uext->magic = ext.magic;
+ uext->len = ext.len;
+ QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next);
+
+ ret = bdrv_pread(bs->file, offset , uext->data, uext->len);
+ if (ret < 0) {
+ return ret;
+ }
+ }
break;
}
+
+ offset += ((ext.len + 7) & ~7);
}
return 0;
}
+static void cleanup_unknown_header_ext(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ Qcow2UnknownHeaderExtension *uext, *next;
+
+ QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) {
+ QLIST_REMOVE(uext, next);
+ g_free(uext);
+ }
+}
+
+static void GCC_FMT_ATTR(2, 3) report_unsupported(BlockDriverState *bs,
+ const char *fmt, ...)
+{
+ char msg[64];
+ va_list ap;
+
+ va_start(ap, fmt);
+ vsnprintf(msg, sizeof(msg), fmt, ap);
+ va_end(ap);
+
+ qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+ bs->device_name, "qcow2", msg);
+}
+
+static void report_unsupported_feature(BlockDriverState *bs,
+ Qcow2Feature *table, uint64_t mask)
+{
+ while (table && table->name[0] != '\0') {
+ if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
+ if (mask & (1 << table->bit)) {
+ report_unsupported(bs, "%.46s",table->name);
+ mask &= ~(1 << table->bit);
+ }
+ }
+ table++;
+ }
+
+ if (mask) {
+ report_unsupported(bs, "Unknown incompatible feature: %" PRIx64, mask);
+ }
+}
-static int qcow2_open(BlockDriverState *bs, int flags)
+/*
+ * Sets the dirty bit and flushes afterwards if necessary.
+ *
+ * The incompatible_features bit is only set if the image file header was
+ * updated successfully. Therefore it is not required to check the return
+ * value of this function.
+ */
+int qcow2_mark_dirty(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ uint64_t val;
+ int ret;
+
+ assert(s->qcow_version >= 3);
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+ return 0; /* already dirty */
+ }
+
+ val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY);
+ ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features),
+ &val, sizeof(val));
+ if (ret < 0) {
+ return ret;
+ }
+ ret = bdrv_flush(bs->file);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Only treat image as dirty if the header was updated successfully */
+ s->incompatible_features |= QCOW2_INCOMPAT_DIRTY;
+ return 0;
+}
+
+/*
+ * Clears the dirty bit and flushes before if necessary. Only call this
+ * function when there are no pending requests, it does not guard against
+ * concurrent requests dirtying the image.
+ */
+static int qcow2_mark_clean(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+ int ret = bdrv_flush(bs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY;
+ return qcow2_update_header(bs);
+ }
+ return 0;
+}
+
+static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
+ BdrvCheckMode fix)
+{
+ int ret = qcow2_check_refcounts(bs, result, fix);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (fix && result->check_errors == 0 && result->corruptions == 0) {
+ return qcow2_mark_clean(bs);
+ }
+ return ret;
+}
+
+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;
- bool writethrough;
+ uint64_t l1_vm_state_index;
ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
if (ret < 0) {
be32_to_cpus(&header.nb_snapshots);
if (header.magic != QCOW_MAGIC) {
- ret = -EINVAL;
+ ret = -EMEDIUMTYPE;
goto fail;
}
- if (header.version != QCOW_VERSION) {
- char version[64];
- snprintf(version, sizeof(version), "QCOW version %d", header.version);
- qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
- bs->device_name, "qcow2", version);
+ if (header.version < 2 || header.version > 3) {
+ report_unsupported(bs, "QCOW version %d", header.version);
ret = -ENOTSUP;
goto fail;
}
+
+ s->qcow_version = header.version;
+
+ /* Initialise version 3 header fields */
+ if (header.version == 2) {
+ header.incompatible_features = 0;
+ header.compatible_features = 0;
+ header.autoclear_features = 0;
+ header.refcount_order = 4;
+ header.header_length = 72;
+ } else {
+ be64_to_cpus(&header.incompatible_features);
+ be64_to_cpus(&header.compatible_features);
+ be64_to_cpus(&header.autoclear_features);
+ be32_to_cpus(&header.refcount_order);
+ be32_to_cpus(&header.header_length);
+ }
+
+ if (header.header_length > sizeof(header)) {
+ s->unknown_header_fields_size = header.header_length - sizeof(header);
+ s->unknown_header_fields = g_malloc(s->unknown_header_fields_size);
+ ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
+ s->unknown_header_fields_size);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ if (header.backing_file_offset) {
+ ext_end = header.backing_file_offset;
+ } else {
+ ext_end = 1 << header.cluster_bits;
+ }
+
+ /* Handle feature bits */
+ s->incompatible_features = header.incompatible_features;
+ s->compatible_features = header.compatible_features;
+ s->autoclear_features = header.autoclear_features;
+
+ if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
+ void *feature_table = NULL;
+ qcow2_read_extensions(bs, header.header_length, ext_end,
+ &feature_table);
+ report_unsupported_feature(bs, feature_table,
+ s->incompatible_features &
+ ~QCOW2_INCOMPAT_MASK);
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ /* Check support for various header values */
+ if (header.refcount_order != 4) {
+ report_unsupported(bs, "%d bit reference counts",
+ 1 << header.refcount_order);
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
if (header.cluster_bits < MIN_CLUSTER_BITS ||
header.cluster_bits > MAX_CLUSTER_BITS) {
ret = -EINVAL;
/* 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) {
}
/* alloc L2 table/refcount block cache */
- writethrough = ((flags & BDRV_O_CACHE_WB) == 0);
- s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE, writethrough);
- s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE,
- writethrough);
+ s->l2_table_cache = qcow2_cache_create(bs, L2_CACHE_SIZE);
+ s->refcount_block_cache = qcow2_cache_create(bs, REFCOUNT_CACHE_SIZE);
s->cluster_cache = g_malloc(s->cluster_size);
/* one more sector for decompressed data alignment */
}
QLIST_INIT(&s->cluster_allocs);
+ QTAILQ_INIT(&s->discards);
/* read qcow2 extensions */
- if (header.backing_file_offset) {
- ext_end = header.backing_file_offset;
- } else {
- ext_end = s->cluster_size;
- }
- if (qcow2_read_extensions(bs, sizeof(header), ext_end)) {
+ if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL)) {
ret = -EINVAL;
goto fail;
}
goto fail;
}
+ /* Clear unknown autoclear feature bits */
+ if (!bs->read_only && s->autoclear_features != 0) {
+ s->autoclear_features = 0;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
/* Initialise locks */
qemu_co_mutex_init(&s->lock);
+ /* Repair image if dirty */
+ if (!(flags & BDRV_O_CHECK) && !bs->read_only &&
+ (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) {
+ BdrvCheckResult result = {0};
+
+ ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ /* 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};
- qcow2_check_refcounts(bs, &result);
+ qcow2_check_refcounts(bs, &result, 0);
}
#endif
return ret;
fail:
+ g_free(s->unknown_header_fields);
+ cleanup_unknown_header_ext(bs);
qcow2_free_snapshots(bs);
qcow2_refcount_close(bs);
g_free(s->l1_table);
return 0;
}
+/* We have nothing to do for QCOW2 reopen, stubs just return
+ * success */
+static int qcow2_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ return 0;
+}
+
static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum)
{
int ret;
*pnum = nb_sectors;
- /* FIXME We can get errors here, but the bdrv_co_is_allocated interface
- * can't pass them on today */
qemu_co_mutex_lock(&s->lock);
ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
- *pnum = 0;
+ return ret;
}
- return (cluster_offset != 0);
+ return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO);
}
/* handle reading after the end of the backing file */
else
n1 = bs->total_sectors - sector_num;
- qemu_iovec_memset_skip(qiov, 0, 512 * (nb_sectors - n1), 512 * n1);
+ qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1));
return n1;
}
index_in_cluster = sector_num & (s->cluster_sectors - 1);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
cur_nr_sectors * 512);
- if (!cluster_offset) {
+ switch (ret) {
+ case QCOW2_CLUSTER_UNALLOCATED:
if (bs->backing_hd) {
/* read from the base image */
}
} else {
/* Note: in this case, no need to wait */
- qemu_iovec_memset(&hd_qiov, 0, 512 * cur_nr_sectors);
+ qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
}
- } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
+ break;
+
+ case QCOW2_CLUSTER_ZERO:
+ qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors);
+ break;
+
+ case QCOW2_CLUSTER_COMPRESSED:
/* add AIO support for compressed blocks ? */
ret = qcow2_decompress_cluster(bs, cluster_offset);
if (ret < 0) {
goto fail;
}
- qemu_iovec_from_buffer(&hd_qiov,
+ qemu_iovec_from_buf(&hd_qiov, 0,
s->cluster_cache + index_in_cluster * 512,
512 * cur_nr_sectors);
- } else {
+ break;
+
+ case QCOW2_CLUSTER_NORMAL:
if ((cluster_offset & 511) != 0) {
ret = -EIO;
goto fail;
if (s->crypt_method) {
qcow2_encrypt_sectors(s, sector_num, cluster_data,
cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);
- qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
- cur_nr_sectors * 512);
- qemu_iovec_from_buffer(&hd_qiov, cluster_data,
- 512 * cur_nr_sectors);
+ qemu_iovec_from_buf(qiov, bytes_done,
+ cluster_data, 512 * cur_nr_sectors);
}
+ break;
+
+ default:
+ g_assert_not_reached();
+ ret = -EIO;
+ goto fail;
}
remaining_sectors -= cur_nr_sectors;
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,
QEMUIOVector hd_qiov;
uint64_t bytes_done = 0;
uint8_t *cluster_data = NULL;
- QCowL2Meta l2meta = {
- .nb_clusters = 0,
- };
+ QCowL2Meta *l2meta = NULL;
- qemu_co_queue_init(&l2meta.dependent_requests);
+ trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,
+ remaining_sectors);
qemu_iovec_init(&hd_qiov, qiov->niov);
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;
if (s->crypt_method &&
}
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;
}
- cluster_offset = l2meta.cluster_offset;
assert((cluster_offset & 511) == 0);
qemu_iovec_reset(&hd_qiov);
- qemu_iovec_copy(&hd_qiov, qiov, bytes_done,
+ qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
cur_nr_sectors * 512);
if (s->crypt_method) {
assert(hd_qiov.size <=
QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
- qemu_iovec_to_buffer(&hd_qiov, cluster_data);
+ qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size);
qcow2_encrypt_sectors(s, sector_num, cluster_data,
cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key);
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,
(cluster_offset >> 9) + index_in_cluster,
cur_nr_sectors, &hd_qiov);
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;
+ }
- run_dependent_requests(s, &l2meta);
+ /* 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);
+
+ next = l2meta->next;
+ g_free(l2meta);
+ l2meta = next;
+ }
remaining_sectors -= cur_nr_sectors;
sector_num += cur_nr_sectors;
bytes_done += cur_nr_sectors * 512;
+ trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors);
}
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);
return ret;
}
qcow2_cache_flush(bs, s->l2_table_cache);
qcow2_cache_flush(bs, s->refcount_block_cache);
+ qcow2_mark_clean(bs);
+
qcow2_cache_destroy(bs, s->l2_table_cache);
qcow2_cache_destroy(bs, s->refcount_block_cache);
+ g_free(s->unknown_header_fields);
+ cleanup_unknown_header_ext(bs);
+
g_free(s->cluster_cache);
qemu_vfree(s->cluster_data);
qcow2_refcount_close(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,
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;
}
}
+static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
+ size_t len, size_t buflen)
+{
+ QCowExtension *ext_backing_fmt = (QCowExtension*) buf;
+ size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7);
+
+ if (buflen < ext_len) {
+ return -ENOSPC;
+ }
+
+ *ext_backing_fmt = (QCowExtension) {
+ .magic = cpu_to_be32(magic),
+ .len = cpu_to_be32(len),
+ };
+ memcpy(buf + sizeof(QCowExtension), s, len);
+
+ return ext_len;
+}
+
/*
- * Updates the variable length parts of the qcow2 header, i.e. the backing file
- * name and all extensions. qcow2 was not designed to allow such changes, so if
- * we run out of space (we can only use the first cluster) this function may
- * fail.
+ * Updates the qcow2 header, including the variable length parts of it, i.e.
+ * the backing file name and all extensions. qcow2 was not designed to allow
+ * such changes, so if we run out of space (we can only use the first cluster)
+ * this function may fail.
*
* Returns 0 on success, -errno in error cases.
*/
-static int qcow2_update_ext_header(BlockDriverState *bs,
- const char *backing_file, const char *backing_fmt)
+int qcow2_update_header(BlockDriverState *bs)
{
- size_t backing_file_len = 0;
- size_t backing_fmt_len = 0;
BDRVQcowState *s = bs->opaque;
- QCowExtension ext_backing_fmt = {0, 0};
+ QCowHeader *header;
+ char *buf;
+ size_t buflen = s->cluster_size;
int ret;
+ uint64_t total_size;
+ uint32_t refcount_table_clusters;
+ size_t header_length;
+ Qcow2UnknownHeaderExtension *uext;
- /* Backing file format doesn't make sense without a backing file */
- if (backing_fmt && !backing_file) {
- return -EINVAL;
- }
+ buf = qemu_blockalign(bs, buflen);
- /* Prepare the backing file format extension if needed */
- if (backing_fmt) {
- ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
- ext_backing_fmt.magic = cpu_to_be32(QCOW2_EXT_MAGIC_BACKING_FORMAT);
- backing_fmt_len = ((sizeof(ext_backing_fmt)
- + strlen(backing_fmt) + 7) & ~7);
- }
+ /* Header structure */
+ header = (QCowHeader*) buf;
- /* Check if we can fit the new header into the first cluster */
- if (backing_file) {
- backing_file_len = strlen(backing_file);
+ if (buflen < sizeof(*header)) {
+ ret = -ENOSPC;
+ goto fail;
}
- size_t header_size = sizeof(QCowHeader) + backing_file_len
- + backing_fmt_len;
+ header_length = sizeof(*header) + s->unknown_header_fields_size;
+ total_size = bs->total_sectors * BDRV_SECTOR_SIZE;
+ refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
+
+ *header = (QCowHeader) {
+ /* Version 2 fields */
+ .magic = cpu_to_be32(QCOW_MAGIC),
+ .version = cpu_to_be32(s->qcow_version),
+ .backing_file_offset = 0,
+ .backing_file_size = 0,
+ .cluster_bits = cpu_to_be32(s->cluster_bits),
+ .size = cpu_to_be64(total_size),
+ .crypt_method = cpu_to_be32(s->crypt_method_header),
+ .l1_size = cpu_to_be32(s->l1_size),
+ .l1_table_offset = cpu_to_be64(s->l1_table_offset),
+ .refcount_table_offset = cpu_to_be64(s->refcount_table_offset),
+ .refcount_table_clusters = cpu_to_be32(refcount_table_clusters),
+ .nb_snapshots = cpu_to_be32(s->nb_snapshots),
+ .snapshots_offset = cpu_to_be64(s->snapshots_offset),
+
+ /* Version 3 fields */
+ .incompatible_features = cpu_to_be64(s->incompatible_features),
+ .compatible_features = cpu_to_be64(s->compatible_features),
+ .autoclear_features = cpu_to_be64(s->autoclear_features),
+ .refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT),
+ .header_length = cpu_to_be32(header_length),
+ };
- if (header_size > s->cluster_size) {
- return -ENOSPC;
+ /* For older versions, write a shorter header */
+ switch (s->qcow_version) {
+ case 2:
+ ret = offsetof(QCowHeader, incompatible_features);
+ break;
+ case 3:
+ ret = sizeof(*header);
+ break;
+ default:
+ ret = -EINVAL;
+ goto fail;
}
- /* Rewrite backing file name and qcow2 extensions */
- size_t ext_size = header_size - sizeof(QCowHeader);
- uint8_t buf[ext_size];
- size_t offset = 0;
- size_t backing_file_offset = 0;
+ buf += ret;
+ buflen -= ret;
+ memset(buf, 0, buflen);
- if (backing_file) {
- if (backing_fmt) {
- int padding = backing_fmt_len -
- (sizeof(ext_backing_fmt) + strlen(backing_fmt));
-
- memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
- offset += sizeof(ext_backing_fmt);
+ /* Preserve any unknown field in the header */
+ if (s->unknown_header_fields_size) {
+ if (buflen < s->unknown_header_fields_size) {
+ ret = -ENOSPC;
+ goto fail;
+ }
- memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
- offset += strlen(backing_fmt);
+ memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size);
+ buf += s->unknown_header_fields_size;
+ buflen -= s->unknown_header_fields_size;
+ }
- memset(buf + offset, 0, padding);
- offset += padding;
+ /* Backing file format header extension */
+ if (*bs->backing_format) {
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT,
+ bs->backing_format, strlen(bs->backing_format),
+ buflen);
+ if (ret < 0) {
+ goto fail;
}
- memcpy(buf + offset, backing_file, backing_file_len);
- backing_file_offset = sizeof(QCowHeader) + offset;
+ buf += ret;
+ buflen -= ret;
}
- ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
+ /* Feature table */
+ Qcow2Feature features[] = {
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_DIRTY_BITNR,
+ .name = "dirty bit",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_COMPATIBLE,
+ .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
+ .name = "lazy refcounts",
+ },
+ };
+
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,
+ features, sizeof(features), buflen);
if (ret < 0) {
goto fail;
}
+ buf += ret;
+ buflen -= ret;
- /* Update header fields */
- uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
- uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
+ /* Keep unknown header extensions */
+ QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
+ ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ }
- ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
- &be_backing_file_offset, sizeof(uint64_t));
+ /* End of header extensions */
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen);
if (ret < 0) {
goto fail;
}
- ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
- &be_backing_file_size, sizeof(uint32_t));
+ buf += ret;
+ buflen -= ret;
+
+ /* Backing file name */
+ if (*bs->backing_file) {
+ size_t backing_file_len = strlen(bs->backing_file);
+
+ if (buflen < backing_file_len) {
+ ret = -ENOSPC;
+ goto fail;
+ }
+
+ /* Using strncpy is ok here, since buf is not NUL-terminated. */
+ strncpy(buf, bs->backing_file, buflen);
+
+ header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
+ header->backing_file_size = cpu_to_be32(backing_file_len);
+ }
+
+ /* Write the new header */
+ ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
if (ret < 0) {
goto fail;
}
ret = 0;
fail:
+ qemu_vfree(header);
return ret;
}
static int qcow2_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt)
{
- return qcow2_update_ext_header(bs, backing_file, backing_fmt);
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
+ pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
+
+ return qcow2_update_header(bs);
}
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 */
* 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;
}
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)
+ QEMUOptionParameter *options, int version)
{
/* Calculate cluster_bits */
int cluster_bits;
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;
}
/* Write the header */
memset(&header, 0, sizeof(header));
header.magic = cpu_to_be32(QCOW_MAGIC);
- header.version = cpu_to_be32(QCOW_VERSION);
+ header.version = cpu_to_be32(version);
header.cluster_bits = cpu_to_be32(cluster_bits);
header.size = cpu_to_be64(0);
header.l1_table_offset = cpu_to_be64(0);
header.l1_size = cpu_to_be32(0);
header.refcount_table_offset = cpu_to_be64(cluster_size);
header.refcount_table_clusters = cpu_to_be32(1);
+ header.refcount_order = cpu_to_be32(3 + REFCOUNT_SHIFT);
+ header.header_length = cpu_to_be32(sizeof(header));
if (flags & BLOCK_FLAG_ENCRYPT) {
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
}
+ if (flags & BLOCK_FLAG_LAZY_REFCOUNTS) {
+ header.compatible_features |=
+ cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
+ }
+
ret = bdrv_pwrite(bs, 0, &header, sizeof(header));
if (ret < 0) {
goto out;
*/
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;
/* And if we're supposed to preallocate metadata, do that now */
if (prealloc) {
+ BDRVQcowState *s = bs->opaque;
+ qemu_co_mutex_lock(&s->lock);
ret = preallocate(bs);
+ qemu_co_mutex_unlock(&s->lock);
if (ret < 0) {
goto out;
}
int flags = 0;
size_t cluster_size = DEFAULT_CLUSTER_SIZE;
int prealloc = 0;
+ int version = 2;
/* Read out options */
while (options && options->name) {
options->value.s);
return -EINVAL;
}
+ } else if (!strcmp(options->name, BLOCK_OPT_COMPAT_LEVEL)) {
+ if (!options->value.s || !strcmp(options->value.s, "0.10")) {
+ version = 2;
+ } else if (!strcmp(options->value.s, "1.1")) {
+ version = 3;
+ } else {
+ fprintf(stderr, "Invalid compatibility level: '%s'\n",
+ options->value.s);
+ return -EINVAL;
+ }
+ } else if (!strcmp(options->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
+ flags |= options->value.n ? BLOCK_FLAG_LAZY_REFCOUNTS : 0;
}
options++;
}
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;
+ }
+
return qcow2_create2(filename, sectors, backing_file, backing_fmt, flags,
- cluster_size, prealloc, options);
+ cluster_size, prealloc, options, version);
}
static int qcow2_make_empty(BlockDriverState *bs)
return 0;
}
+static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors)
+{
+ int ret;
+ BDRVQcowState *s = bs->opaque;
+
+ /* Emulate misaligned zero writes */
+ if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) {
+ return -ENOTSUP;
+ }
+
+ /* Whatever is left can use real zero clusters */
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS,
+ nb_sectors);
+ qemu_co_mutex_unlock(&s->lock);
+
+ return ret;
+}
+
static coroutine_fn int qcow2_co_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
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");
return -EINVAL;
}
/* cannot proceed if image has snapshots */
if (s->nb_snapshots) {
+ error_report("Can't resize an image which has snapshots");
return -ENOTSUP;
}
/* shrinking is currently not supported */
if (offset < bs->total_sectors * 512) {
+ error_report("qcow2 doesn't support shrinking images yet");
return -ENOTSUP;
}
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);
return ret;
}
- ret = qcow2_cache_flush(bs, s->refcount_block_cache);
- if (ret < 0) {
- qemu_co_mutex_unlock(&s->lock);
- return ret;
+ if (qcow2_need_accurate_refcounts(s)) {
+ ret = qcow2_cache_flush(bs, s->refcount_block_cache);
+ if (ret < 0) {
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+ }
}
qemu_co_mutex_unlock(&s->lock);
return 0;
}
-static coroutine_fn int qcow2_co_flush_to_disk(BlockDriverState *bs)
-{
- return bdrv_co_flush(bs->file);
-}
-
static int64_t qcow2_vm_state_offset(BDRVQcowState *s)
{
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
return 0;
}
-
-static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result)
-{
- return qcow2_check_refcounts(bs, result);
-}
-
#if 0
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;
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;
.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,
.type = OPT_STRING,
.help = "Preallocation mode (allowed values: off, metadata)"
},
+ {
+ .name = BLOCK_OPT_LAZY_REFCOUNTS,
+ .type = OPT_FLAG,
+ .help = "Postpone refcount updates",
+ },
{ NULL }
};
.bdrv_probe = qcow2_probe,
.bdrv_open = qcow2_open,
.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,
.bdrv_co_readv = qcow2_co_readv,
.bdrv_co_writev = qcow2_co_writev,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
- .bdrv_co_flush_to_disk = qcow2_co_flush_to_disk,
+ .bdrv_co_write_zeroes = qcow2_co_write_zeroes,
.bdrv_co_discard = qcow2_co_discard,
.bdrv_truncate = qcow2_truncate,
.bdrv_write_compressed = qcow2_write_compressed,