[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 05/28] block: add block_resize monitor command
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PATCH 05/28] block: add block_resize monitor command |
Date: |
Mon, 31 Jan 2011 16:28:53 +0100 |
From: Christoph Hellwig <address@hidden>
Add a monitor command that allows resizing of block devices while
qemu is running. It uses the existing bdrv_truncate method already
used by qemu-img to do it's work. Compared to qemu-img the size
parsing is very simplicistic, but I think having a properly numering
object is more useful for non-humand monitor users than having
the units and relative resize parsing.
For SCSI devices the new size can be updated in Linux guests by
doing the following shell command:
echo > /sys/class/scsi_device/0:0:0:0/device/rescan
For ATA devices I don't know of a way to update the block device
size in Linux system, and for virtio-blk the next two patches
will provide an automatic update of the size when this command
is issued on the host.
Signed-off-by: Christoph Hellwig <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
blockdev.c | 30 ++++++++++++++++++++++++++++++
blockdev.h | 1 +
hmp-commands.hx | 19 +++++++++++++++++++
qmp-commands.hx | 28 ++++++++++++++++++++++++++++
4 files changed, 78 insertions(+), 0 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index f7f591f..e48d33d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -705,3 +705,33 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject
**ret_data)
return 0;
}
+
+/*
+ * XXX: replace the QERR_UNDEFINED_ERROR errors with real values once the
+ * existing QERR_ macro mess is cleaned up. A good example for better
+ * error reports can be found in the qemu-img resize code.
+ */
+int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data)
+{
+ const char *device = qdict_get_str(qdict, "device");
+ int64_t size = qdict_get_int(qdict, "size");
+ BlockDriverState *bs;
+
+ bs = bdrv_find(device);
+ if (!bs) {
+ qerror_report(QERR_DEVICE_NOT_FOUND, device);
+ return -1;
+ }
+
+ if (size < 0) {
+ qerror_report(QERR_UNDEFINED_ERROR);
+ return -1;
+ }
+
+ if (bdrv_truncate(bs, size)) {
+ qerror_report(QERR_UNDEFINED_ERROR);
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/blockdev.h b/blockdev.h
index 4536b5c..b8a88bf 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -53,5 +53,6 @@ int do_change_block(Monitor *mon, const char *device,
const char *filename, const char *fmt);
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data);
+int do_block_resize(Monitor *mon, const QDict *qdict, QObject **ret_data);
#endif
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 1cea572..8df4adf 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -53,6 +53,25 @@ Quit the emulator.
ETEXI
{
+ .name = "block_resize",
+ .args_type = "device:B,size:o",
+ .params = "device size",
+ .help = "resize a block image",
+ .user_print = monitor_user_noop,
+ .mhandler.cmd_new = do_block_resize,
+ },
+
+STEXI
address@hidden block_resize
address@hidden block_resize
+Resize a block image while a guest is running. Usually requires guest
+action to see the updated size. Resize to a lower size is supported,
+but should be used with extreme caution. Note that this command only
+resizes image files, it can not resize block devices like LVM volumes.
+ETEXI
+
+
+ {
.name = "eject",
.args_type = "force:-f,device:B",
.params = "[-f] device",
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 56c4d8b..9f79f5f 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -601,6 +601,34 @@ Example:
-> { "execute": "netdev_del", "arguments": { "id": "netdev1" } }
<- { "return": {} }
+
+EQMP
+
+ {
+ .name = "block_resize",
+ .args_type = "device:B,size:o",
+ .params = "device size",
+ .help = "resize a block image",
+ .user_print = monitor_user_noop,
+ .mhandler.cmd_new = do_block_resize,
+ },
+
+SQMP
+block_resize
+------------
+
+Resize a block image while a guest is running.
+
+Arguments:
+
+- "device": the device's ID, must be unique (json-string)
+- "size": new size
+
+Example:
+
+-> { "execute": "block_resize", "arguments": { "device": "scratch", "size":
1073741824 } }
+<- { "return": {} }
+
EQMP
{
--
1.7.2.3
- [Qemu-devel] [PULL 00/28] Block patches, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 01/28] strtosz(): use unsigned char and switch to qemu_isspace(), Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 04/28] strtosz(): Use suffix macros in switch() statement, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 02/28] strtosz() use qemu_toupper() to simplify switch statement, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 07/28] virtio-blk: tell the guest about size changes, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 03/28] strtosz(): Fix name confusion in use of modf(), Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 12/28] sheepdog: support creating images on remote hosts, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 05/28] block: add block_resize monitor command,
Kevin Wolf <=
- [Qemu-devel] [PATCH 08/28] virtio-pci: Disable virtio-ioeventfd when !CONFIG_IOTHREAD, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 10/28] ahci: Fix cpu_physical_memory_unmap() argument ordering, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 18/28] qcow2-refcount: remove write-only variables, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 15/28] qed: Images with backing file do not require QED_F_NEED_CHECK, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 11/28] Reorganize struct Qcow2Cache for better struct packing, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 14/28] qcow2: Add bdrv_discard support, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 17/28] scsi hotplug: Set DriveInfo member bus correctly, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 16/28] raw-win32: Fix bdrv_flush return value, Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 24/28] blockdev: Factor drive_index_to_{bus, unit}_id out of drive_init(), Kevin Wolf, 2011/01/31
- [Qemu-devel] [PATCH 27/28] blockdev: Replace drive_add()'s fmt, ... by optstr parameter, Kevin Wolf, 2011/01/31