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authorMax Reitz <mreitz@redhat.com>2017-06-13 22:20:55 +0200
committerMax Reitz <mreitz@redhat.com>2017-07-11 17:45:01 +0200
commitdc5f690b97ccdffa79fe7169bb26b0ebf06688bf (patch)
treecb7ba74b70e9e8ddcd164a6b03082fb8c69386aa /qemu-img.c
parent3a691c50f10344b052ad70a4d0ed935276ccca3c (diff)
qemu-img: Expose PreallocMode for resizing
Add a --preallocation command line option to qemu-img resize which can be used to set the PreallocMode parameter of blk_truncate(). While touching this code, fix the fact that we did not handle errors returned by blk_getlength(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170613202107.10125-5-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'qemu-img.c')
-rw-r--r--qemu-img.c33
1 files changed, 30 insertions, 3 deletions
diff --git a/qemu-img.c b/qemu-img.c
index 1b741956bc..28022145d5 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -24,6 +24,7 @@
#include "qemu/osdep.h"
#include "qemu-version.h"
#include "qapi/error.h"
+#include "qapi/util.h"
#include "qapi-visit.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/qmp/qerror.h"
@@ -62,6 +63,7 @@ enum {
OPTION_NO_DRAIN = 262,
OPTION_TARGET_IMAGE_OPTS = 263,
OPTION_SIZE = 264,
+ OPTION_PREALLOCATION = 265,
};
typedef enum OutputFormat {
@@ -3408,9 +3410,10 @@ static int img_resize(int argc, char **argv)
Error *err = NULL;
int c, ret, relative;
const char *filename, *fmt, *size;
- int64_t n, total_size;
+ int64_t n, total_size, current_size;
bool quiet = false;
BlockBackend *blk = NULL;
+ PreallocMode prealloc = PREALLOC_MODE_OFF;
QemuOpts *param;
static QemuOptsList resize_options = {
@@ -3444,6 +3447,7 @@ static int img_resize(int argc, char **argv)
{"help", no_argument, 0, 'h'},
{"object", required_argument, 0, OPTION_OBJECT},
{"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
+ {"preallocation", required_argument, 0, OPTION_PREALLOCATION},
{0, 0, 0, 0}
};
c = getopt_long(argc, argv, ":f:hq",
@@ -3478,6 +3482,15 @@ static int img_resize(int argc, char **argv)
case OPTION_IMAGE_OPTS:
image_opts = true;
break;
+ case OPTION_PREALLOCATION:
+ prealloc = qapi_enum_parse(PreallocMode_lookup, optarg,
+ PREALLOC_MODE__MAX, PREALLOC_MODE__MAX,
+ NULL);
+ if (prealloc == PREALLOC_MODE__MAX) {
+ error_report("Invalid preallocation mode '%s'", optarg);
+ return 1;
+ }
+ break;
}
}
if (optind != argc - 1) {
@@ -3526,8 +3539,16 @@ static int img_resize(int argc, char **argv)
goto out;
}
+ current_size = blk_getlength(blk);
+ if (current_size < 0) {
+ error_report("Failed to inquire current image length: %s",
+ strerror(-current_size));
+ ret = -1;
+ goto out;
+ }
+
if (relative) {
- total_size = blk_getlength(blk) + n * relative;
+ total_size = current_size + n * relative;
} else {
total_size = n;
}
@@ -3537,7 +3558,13 @@ static int img_resize(int argc, char **argv)
goto out;
}
- ret = blk_truncate(blk, total_size, PREALLOC_MODE_OFF, &err);
+ if (total_size <= current_size && prealloc != PREALLOC_MODE_OFF) {
+ error_report("Preallocation can only be used for growing images");
+ ret = -1;
+ goto out;
+ }
+
+ ret = blk_truncate(blk, total_size, prealloc, &err);
if (!ret) {
qprintf(quiet, "Image resized.\n");
} else {