Fix savevm after BDRV_FILE size enforcement
We now enforce that you cannot write beyond the end of a non-growable file.
qcow2 files are not growable but we rely on them being growable to do
savevm/loadvm. Temporarily allow them to be growable by introducing a new
API specifically for savevm read/write operations.
Reported-by: malc
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6994 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/block-qcow2.c b/block-qcow2.c
index d99811d..6eba524 100644
--- a/block-qcow2.c
+++ b/block-qcow2.c
@@ -2721,6 +2721,31 @@
#endif
#endif
+static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,
+ int64_t pos, int size)
+{
+ int growable = bs->growable;
+
+ bs->growable = 1;
+ bdrv_pwrite(bs, pos, buf, size);
+ bs->growable = growable;
+
+ return size;
+}
+
+static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf,
+ int64_t pos, int size)
+{
+ int growable = bs->growable;
+ int ret;
+
+ bs->growable = 1;
+ ret = bdrv_pread(bs, pos, buf, size);
+ bs->growable = growable;
+
+ return ret;
+}
+
BlockDriver bdrv_qcow2 = {
.format_name = "qcow2",
.instance_size = sizeof(BDRVQcowState),
@@ -2745,5 +2770,8 @@
.bdrv_snapshot_list = qcow_snapshot_list,
.bdrv_get_info = qcow_get_info,
+ .bdrv_put_buffer = qcow_put_buffer,
+ .bdrv_get_buffer = qcow_get_buffer,
+
.bdrv_create2 = qcow_create2,
};
diff --git a/block.c b/block.c
index 4da3bcb..dd40b56 100644
--- a/block.c
+++ b/block.c
@@ -1146,6 +1146,26 @@
return drv->bdrv_get_info(bs, bdi);
}
+int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf, int64_t pos, int size)
+{
+ BlockDriver *drv = bs->drv;
+ if (!drv)
+ return -ENOMEDIUM;
+ if (!drv->bdrv_put_buffer)
+ return -ENOTSUP;
+ return drv->bdrv_put_buffer(bs, buf, pos, size);
+}
+
+int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size)
+{
+ BlockDriver *drv = bs->drv;
+ if (!drv)
+ return -ENOMEDIUM;
+ if (!drv->bdrv_get_buffer)
+ return -ENOTSUP;
+ return drv->bdrv_get_buffer(bs, buf, pos, size);
+}
+
/**************************************************************/
/* handling of snapshots */
diff --git a/block.h b/block.h
index 6701d34..f1919b6 100644
--- a/block.h
+++ b/block.h
@@ -178,4 +178,9 @@
const char *base_path,
const char *filename);
+int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf,
+ int64_t pos, int size);
+
+int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size);
+
#endif
diff --git a/block_int.h b/block_int.h
index af6dff6..dc43359 100644
--- a/block_int.h
+++ b/block_int.h
@@ -78,6 +78,11 @@
QEMUSnapshotInfo **psn_info);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
+ int (*bdrv_put_buffer)(BlockDriverState *bs, const uint8_t *buf,
+ int64_t pos, int size);
+ int (*bdrv_get_buffer)(BlockDriverState *bs, uint8_t *buf,
+ int64_t pos, int size);
+
/* removable device specific */
int (*bdrv_is_inserted)(BlockDriverState *bs);
int (*bdrv_media_changed)(BlockDriverState *bs);
diff --git a/savevm.c b/savevm.c
index ce12628..793ea70 100644
--- a/savevm.c
+++ b/savevm.c
@@ -310,18 +310,18 @@
int64_t base_offset;
} QEMUFileBdrv;
-static int bdrv_put_buffer(void *opaque, const uint8_t *buf,
+static int block_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
QEMUFileBdrv *s = opaque;
- bdrv_pwrite(s->bs, s->base_offset + pos, buf, size);
+ bdrv_put_buffer(s->bs, buf, s->base_offset + pos, size);
return size;
}
-static int bdrv_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
+static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
QEMUFileBdrv *s = opaque;
- return bdrv_pread(s->bs, s->base_offset + pos, buf, size);
+ return bdrv_get_buffer(s->bs, buf, s->base_offset + pos, size);
}
static int bdrv_fclose(void *opaque)
@@ -341,9 +341,9 @@
s->base_offset = offset;
if (is_writable)
- return qemu_fopen_ops(s, bdrv_put_buffer, NULL, bdrv_fclose, NULL);
+ return qemu_fopen_ops(s, block_put_buffer, NULL, bdrv_fclose, NULL);
- return qemu_fopen_ops(s, NULL, bdrv_get_buffer, bdrv_fclose, NULL);
+ return qemu_fopen_ops(s, NULL, block_get_buffer, bdrv_fclose, NULL);
}
QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
