diff options
| -rw-r--r-- | qemu-img-cmds.hx | 4 | ||||
| -rw-r--r-- | qemu-img.c | 32 | ||||
| -rw-r--r-- | qemu-img.texi | 12 |
3 files changed, 36 insertions, 12 deletions
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index fde33d1860..04c207da8d 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] [-d] [-p] filename") + "commit [-q] [-f fmt] [-t cache] [-b base] [-d] [-p] filename") STEXI -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] [-p] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename} ETEXI DEF("compare", img_compare, diff --git a/qemu-img.c b/qemu-img.c index 8fec160c37..bd5a2ae22e 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -759,7 +759,7 @@ static void run_block_job(BlockJob *job, Error **errp) static int img_commit(int argc, char **argv) { int c, ret, flags; - const char *filename, *fmt, *cache; + const char *filename, *fmt, *cache, *base; BlockBackend *blk; BlockDriverState *bs, *base_bs; bool progress = false, quiet = false, drop = false; @@ -768,8 +768,9 @@ static int img_commit(int argc, char **argv) fmt = NULL; cache = BDRV_DEFAULT_CACHE; + base = NULL; for(;;) { - c = getopt(argc, argv, "f:ht:dpq"); + c = getopt(argc, argv, "f:ht:b:dpq"); if (c == -1) { break; } @@ -784,6 +785,11 @@ static int img_commit(int argc, char **argv) case 't': cache = optarg; break; + case 'b': + base = optarg; + /* -b implies -d */ + drop = true; + break; case 'd': drop = true; break; @@ -822,13 +828,21 @@ static int img_commit(int argc, char **argv) qemu_progress_init(progress, 1.f); qemu_progress_print(0.f, 100); - /* 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_setg(&local_err, "Image does not have a backing file"); - goto done; + if (base) { + base_bs = bdrv_find_backing_image(bs, base); + if (!base_bs) { + error_set(&local_err, QERR_BASE_NOT_FOUND, base); + goto done; + } + } else { + /* 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_setg(&local_err, "Image does not have a backing file"); + goto done; + } } cbi = (CommonBlockJobCBInfo){ diff --git a/qemu-img.texi b/qemu-img.texi index f82d1b4923..078851adb6 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. -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] [-p] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @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 @@ -180,6 +180,16 @@ 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 @var{filename} by specifying the @code{-d} flag. +If the backing chain of the given image file @var{filename} has more than one +layer, the backing file into which the changes will be committed may be +specified as @var{base} (which has to be part of @var{filename}'s backing +chain). If @var{base} is not specified, the immediate backing file of the top +image (which is @var{filename}) will be used. For reasons of consistency, +explicitly specifying @var{base} will always imply @code{-d} (since emptying an +image after committing to an indirect backing file would lead to different data +being read from the image due to content in the intermediate backing chain +overruling the commit target). + @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 |