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[Qemu-devel] [PATCH for-2.10 04/16] qemu-img: Expose PreallocMode for re
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH for-2.10 04/16] qemu-img: Expose PreallocMode for resizing |
Date: |
Mon, 13 Mar 2017 22:40:33 +0100 |
Add a --preallocation command line option to qemu-img resize which can
be used to set the PreallocMode parameter of blk_truncate().
Signed-off-by: Max Reitz <address@hidden>
---
qemu-img.c | 33 ++++++++++++++++++++++++++++++---
qemu-img.texi | 7 ++++++-
2 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index 3e637a932b..a5fdd30202 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"
@@ -59,6 +60,7 @@ enum {
OPTION_PATTERN = 260,
OPTION_FLUSH_INTERVAL = 261,
OPTION_NO_DRAIN = 262,
+ OPTION_PREALLOCATION = 263,
};
typedef enum OutputFormat {
@@ -3317,9 +3319,10 @@ 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 = {
@@ -3353,6 +3356,7 @@ 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",
@@ -3382,6 +3386,15 @@ 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) {
@@ -3429,8 +3442,16 @@ 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\n",
+ 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;
}
@@ -3440,7 +3461,13 @@ 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 {
diff --git a/qemu-img.texi b/qemu-img.texi
index c81db3e81c..ad46fa5f05 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -490,7 +490,7 @@ qemu-img rebase -b base.img diff.qcow2
At this point, @code{modified.img} can be discarded, since
@code{base.img + diff.qcow2} contains the same information.
address@hidden resize @var{filename} [+ | address@hidden
address@hidden resize address@hidden @var{filename} [+ | address@hidden
Change the disk image as if it had been created with @var{size}.
@@ -502,6 +502,11 @@ After using this command to grow a disk image, you must
use file system and
partitioning tools inside the VM to actually begin using the new space on the
device.
+When growing an image, the @code{--preallocation} option may be used to specify
+how the additional image area should be allocated on the host. See the format
+description in the @code{NOTES} section which values are allowed. Using this
+option may result in more data being allocated than necessary.
+
@item amend [-p] [-f @var{fmt}] [-t @var{cache}] -o @var{options}
@var{filename}
Amends the image format specific @var{options} for the image file
--
2.12.0
- Re: [Qemu-devel] [Qemu-block] [PATCH for-2.10 01/16] block: Add PreallocMode to BD.bdrv_truncate(), (continued)
[Qemu-devel] [PATCH for-2.10 02/16] block: Add PreallocMode to bdrv_truncate(), Max Reitz, 2017/03/13
[Qemu-devel] [PATCH for-2.10 05/16] block/file-posix: Small fixes in raw_create(), Max Reitz, 2017/03/13
[Qemu-devel] [PATCH for-2.10 03/16] block: Add PreallocMode to blk_truncate(), Max Reitz, 2017/03/13
[Qemu-devel] [PATCH for-2.10 04/16] qemu-img: Expose PreallocMode for resizing,
Max Reitz <=
[Qemu-devel] [PATCH for-2.10 06/16] block/file-posix: Extract raw_regular_truncate(), Max Reitz, 2017/03/13
[Qemu-devel] [PATCH for-2.10 07/16] block/file-posix: Generalize raw_regular_truncate, Max Reitz, 2017/03/13