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[Qemu-devel] [PULL 29/53] qemu-img: Empty image after commit
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 29/53] qemu-img: Empty image after commit |
Date: |
Mon, 3 Nov 2014 11:50:32 +0000 |
From: Max Reitz <address@hidden>
After the top image has been committed, it should be emptied unless
specified otherwise.
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Kevin Wolf <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
qemu-img-cmds.hx | 4 ++--
qemu-img.c | 34 +++++++++++++++++++++++++++++++---
qemu-img.texi | 6 +++++-
3 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 55aec6b..e2ceadf 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -22,9 +22,9 @@ STEXI
ETEXI
DEF("commit", img_commit,
- "commit [-q] [-f fmt] [-t cache] filename")
+ "commit [-q] [-f fmt] [-t cache] [-d] filename")
STEXI
address@hidden commit [-q] [-f @var{fmt}] [-t @var{cache}] @var{filename}
address@hidden commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] @var{filename}
ETEXI
DEF("compare", img_compare,
diff --git a/qemu-img.c b/qemu-img.c
index 494146d..cf8c01c 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -757,14 +757,14 @@ static int img_commit(int argc, char **argv)
const char *filename, *fmt, *cache;
BlockBackend *blk;
BlockDriverState *bs, *base_bs;
- bool quiet = false;
+ bool quiet = false, drop = false;
Error *local_err = NULL;
CommonBlockJobCBInfo cbi;
fmt = NULL;
cache = BDRV_DEFAULT_CACHE;
for(;;) {
- c = getopt(argc, argv, "f:ht:q");
+ c = getopt(argc, argv, "f:ht:dq");
if (c == -1) {
break;
}
@@ -779,6 +779,9 @@ static int img_commit(int argc, char **argv)
case 't':
cache = optarg;
break;
+ case 'd':
+ drop = true;
+ break;
case 'q':
quiet = true;
break;
@@ -789,7 +792,7 @@ static int img_commit(int argc, char **argv)
}
filename = argv[optind++];
- flags = BDRV_O_RDWR;
+ flags = BDRV_O_RDWR | BDRV_O_UNMAP;
ret = bdrv_parse_cache_flags(cache, &flags);
if (ret < 0) {
error_report("Invalid cache option: %s", cache);
@@ -822,7 +825,32 @@ static int img_commit(int argc, char **argv)
goto done;
}
+ /* The block job will swap base_bs and bs (which is not what we really want
+ * here, but okay) and unref base_bs (after the swap, i.e., the old top
+ * image). In order to still be able to empty that top image afterwards,
+ * increment the reference counter here preemptively. */
+ if (!drop) {
+ bdrv_ref(base_bs);
+ }
+
run_block_job(bs->job, &local_err);
+ if (local_err) {
+ goto unref_backing;
+ }
+
+ if (!drop && base_bs->drv->bdrv_make_empty) {
+ ret = base_bs->drv->bdrv_make_empty(base_bs);
+ if (ret) {
+ error_setg_errno(&local_err, -ret, "Could not empty %s",
+ filename);
+ goto unref_backing;
+ }
+ }
+
+unref_backing:
+ if (!drop) {
+ bdrv_unref(base_bs);
+ }
done:
blk_unref(blk);
diff --git a/qemu-img.texi b/qemu-img.texi
index e3ef4a0..420bd91 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -167,7 +167,7 @@ this case. @var{backing_file} will never be modified unless
you use the
The size can also be specified using the @var{size} option with @code{-o},
it doesn't need to be specified separately in this case.
address@hidden commit [-f @var{fmt}] [-t @var{cache}] @var{filename}
address@hidden commit [-f @var{fmt}] [-t @var{cache}] [-d] @var{filename}
Commit the changes recorded in @var{filename} in its base image or backing
file.
If the backing file is smaller than the snapshot, then the backing file will be
@@ -176,6 +176,10 @@ the backing file, the backing file will not be truncated.
If you want the
backing file to match the size of the smaller snapshot, you can safely truncate
it yourself once the commit operation successfully completes.
+The image @var{filename} is emptied after the operation has succeeded. If you
do
+not need @var{filename} afterwards and intend to drop it, you may skip emptying
address@hidden by specifying the @code{-d} flag.
+
@item compare [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-s]
[-q] @var{filename1} @var{filename2}
Check if two images have the same content. You can compare images with
--
1.9.3
- [Qemu-devel] [PULL 19/53] raw-posix: raw_co_get_block_status() return value, (continued)
- [Qemu-devel] [PULL 19/53] raw-posix: raw_co_get_block_status() return value, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 20/53] iotests: Add test for external image truncation, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 21/53] qcow2: Allow "full" discard, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 22/53] qcow2: Implement bdrv_make_empty(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 23/53] qcow2: Optimize bdrv_make_empty(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 24/53] blockjob: Introduce block_job_complete_sync(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 26/53] iotests: Omit length/offset test in 040 and 041, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 25/53] blockjob: Add "ready" field, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 27/53] block/mirror: Improve progress report, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 28/53] qemu-img: Implement commit like QMP, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 29/53] qemu-img: Empty image after commit,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 30/53] qemu-img: Enable progress output for commit, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 31/53] qemu-img: Specify backing file for commit, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 32/53] iotests: Add _filter_qemu_img_map, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 33/53] iotests: Add test for backing-chain commits, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 34/53] iotests: Add test for qcow2's bdrv_make_empty, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 36/53] block: Add status callback to bdrv_amend_options(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 35/53] block: qemu-iotest 107 supports NFS, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 37/53] qemu-img: Add progress output for amend, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 38/53] qemu-img: Fix insignificant memleak, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 39/53] block/qcow2: Implement status CB for amend, Stefan Hajnoczi, 2014/11/03