qemu-img should use QMP commands whenever possible in order to ensure feature completeness of both online and offline image operations. As qemu-img itself has no access to QMP (since this would basically require just everything being linked into qemu-img), imitate QMP's implementation of block-commit by using commit_active_start() and then waiting for the block job to finish.
This new implementation does not empty the snapshot image, as opposed to the old implementation using bdrv_commit(). However, as QMP's block-commit apparently never did this and as qcow2 (which is probably qemu's standard image format) does not even implement the required function (bdrv_make_empty()), it does not seem necessary. Signed-off-by: Max Reitz <mre...@redhat.com> --- block/Makefile.objs | 2 +- qemu-img.c | 86 +++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 68 insertions(+), 20 deletions(-) diff --git a/block/Makefile.objs b/block/Makefile.objs index fd88c03..2c37e80 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -9,6 +9,7 @@ block-obj-y += snapshot.o qapi.o block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o block-obj-$(CONFIG_POSIX) += raw-posix.o block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o +block-obj-y += mirror.o ifeq ($(CONFIG_POSIX),y) block-obj-y += nbd.o nbd-client.o sheepdog.o @@ -22,7 +23,6 @@ endif common-obj-y += stream.o common-obj-y += commit.o -common-obj-y += mirror.o common-obj-y += backup.o iscsi.o-cflags := $(LIBISCSI_CFLAGS) diff --git a/qemu-img.c b/qemu-img.c index 8455994..9fe6384 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -30,6 +30,7 @@ #include "qemu/osdep.h" #include "sysemu/sysemu.h" #include "block/block_int.h" +#include "block/blockjob.h" #include "block/qapi.h" #include <getopt.h> @@ -682,12 +683,49 @@ fail: return ret; } +struct CommonBlockJobCBInfo { + Error **errp; + bool done; +}; + +static void common_block_job_cb(void *opaque, int ret) +{ + struct CommonBlockJobCBInfo *cbi = opaque; + + if (ret < 0) { + error_setg_errno(cbi->errp, -ret, "Block job failed"); + } + + cbi->done = true; +} + +static void run_block_job(BlockJob *job, struct CommonBlockJobCBInfo *cbi) +{ + BlockJobInfo *info; + + do { + qemu_aio_wait(); + + info = block_job_query(job); + + if (!info->busy && info->offset < info->len) { + block_job_resume(job); + } + } while (info->offset < info->len); + + block_job_complete_sync(job, cbi->errp); +} + +/* Same as in block.c */ +#define COMMIT_BUF_SECTORS 2048 + static int img_commit(int argc, char **argv) { int c, ret, flags; const char *filename, *fmt, *cache; - BlockDriverState *bs; + BlockDriverState *bs, *base_bs; bool quiet = false; + Error *local_err = NULL; fmt = NULL; cache = BDRV_DEFAULT_CACHE; @@ -728,29 +766,39 @@ static int img_commit(int argc, char **argv) if (!bs) { return 1; } - ret = bdrv_commit(bs); - switch(ret) { - case 0: - qprintf(quiet, "Image committed.\n"); - break; - case -ENOENT: - error_report("No disk inserted"); - break; - case -EACCES: - error_report("Image is read-only"); - break; - case -ENOTSUP: - error_report("Image is already committed"); - break; - default: - error_report("Error while committing image"); - break; + + /* This is different from QMP, which by default uses the deepest file in the + * backing chain (i.e., the very base); however, the traditional behavior of + * qemu-img commit is using the immediate backing file. */ + base_bs = bs->backing_hd; + if (!base_bs) { + error_set(&local_err, QERR_BASE_NOT_FOUND, "NULL"); + goto done; } + struct CommonBlockJobCBInfo cbi = { + .errp = &local_err, + }; + + commit_active_start(bs, base_bs, 0, COMMIT_BUF_SECTORS << BDRV_SECTOR_BITS, + BLOCKDEV_ON_ERROR_REPORT, common_block_job_cb, &cbi, + &local_err); + if (local_err) { + goto done; + } + + run_block_job(bs->job, &cbi); + +done: bdrv_unref(bs); - if (ret) { + + if (local_err) { + qerror_report_err(local_err); + error_free(local_err); return 1; } + + qprintf(quiet, "Image committed.\n"); return 0; } -- 1.9.2