* so this seems to be reasonable.
*/
+#include "qemu/osdep.h"
#include "qemu-common.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "migration/migration.h"
+#include "qemu/coroutine.h"
#if defined(CONFIG_UUID)
#include <uuid/uuid.h>
/* VDI header (converted to host endianness). */
VdiHeader header;
+ CoMutex write_lock;
+
Error *migration_blocker;
} BDRVVdiState;
logout("\n");
- ret = bdrv_read(bs->file, 0, (uint8_t *)&header, 1);
+ ret = bdrv_read(bs->file->bs, 0, (uint8_t *)&header, 1);
if (ret < 0) {
goto fail;
}
bmap_size = header.blocks_in_image * sizeof(uint32_t);
bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE);
- s->bmap = qemu_try_blockalign(bs->file, bmap_size * SECTOR_SIZE);
+ s->bmap = qemu_try_blockalign(bs->file->bs, bmap_size * SECTOR_SIZE);
if (s->bmap == NULL) {
ret = -ENOMEM;
goto fail;
}
- ret = bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size);
+ ret = bdrv_read(bs->file->bs, s->bmap_sector, (uint8_t *)s->bmap,
+ bmap_size);
if (ret < 0) {
goto fail_free_bmap;
}
/* Disable migration when vdi images are used */
- error_set(&s->migration_blocker,
- QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
- "vdi", bdrv_get_device_name(bs), "live migration");
+ error_setg(&s->migration_blocker, "The vdi format used by node '%s' "
+ "does not support live migration",
+ bdrv_get_device_or_node_name(bs));
migrate_add_blocker(s->migration_blocker);
+ qemu_co_mutex_init(&s->write_lock);
+
return 0;
fail_free_bmap:
uint64_t offset = s->header.offset_data / SECTOR_SIZE +
(uint64_t)bmap_entry * s->block_sectors +
sector_in_block;
- ret = bdrv_read(bs->file, offset, buf, n_sectors);
+ ret = bdrv_read(bs->file->bs, offset, buf, n_sectors);
}
logout("%u sectors read\n", n_sectors);
buf, n_sectors * SECTOR_SIZE);
memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0,
(s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE);
- ret = bdrv_write(bs->file, offset, block, s->block_sectors);
+
+ /* Note that this coroutine does not yield anywhere from reading the
+ * bmap entry until here, so in regards to all the coroutines trying
+ * to write to this cluster, the one doing the allocation will
+ * always be the first to try to acquire the lock.
+ * Therefore, it is also the first that will actually be able to
+ * acquire the lock and thus the padded cluster is written before
+ * the other coroutines can write to the affected area. */
+ qemu_co_mutex_lock(&s->write_lock);
+ ret = bdrv_write(bs->file->bs, offset, block, s->block_sectors);
+ qemu_co_mutex_unlock(&s->write_lock);
} else {
uint64_t offset = s->header.offset_data / SECTOR_SIZE +
(uint64_t)bmap_entry * s->block_sectors +
sector_in_block;
- ret = bdrv_write(bs->file, offset, buf, n_sectors);
+ qemu_co_mutex_lock(&s->write_lock);
+ /* This lock is only used to make sure the following write operation
+ * is executed after the write issued by the coroutine allocating
+ * this cluster, therefore we do not need to keep it locked.
+ * As stated above, the allocating coroutine will always try to lock
+ * the mutex before all the other concurrent accesses to that
+ * cluster, therefore at this point we can be absolutely certain
+ * that that write operation has returned (there may be other writes
+ * in flight, but they do not concern this very operation). */
+ qemu_co_mutex_unlock(&s->write_lock);
+ ret = bdrv_write(bs->file->bs, offset, buf, n_sectors);
}
nb_sectors -= n_sectors;
assert(VDI_IS_ALLOCATED(bmap_first));
*header = s->header;
vdi_header_to_le(header);
- ret = bdrv_write(bs->file, 0, block, 1);
+ ret = bdrv_write(bs->file->bs, 0, block, 1);
g_free(block);
block = NULL;
base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE;
logout("will write %u block map sectors starting from entry %u\n",
n_sectors, bmap_first);
- ret = bdrv_write(bs->file, offset, base, n_sectors);
+ ret = bdrv_write(bs->file->bs, offset, base, n_sectors);
}
return ret;
goto exit;
}
ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
- NULL, &local_err);
+ &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto exit;
.def_value_str = "off"
},
#endif
- {
- .name = BLOCK_OPT_NOCOW,
- .type = QEMU_OPT_BOOL,
- .help = "Turn off copy-on-write (valid only on btrfs)"
- },
/* TODO: An additional option to set UUID values might be useful. */
{ /* end of list */ }
}