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[Qemu-devel] [PATCH] sanitize ->bdrv_get_buffer / ->bdrv_put_buffer call
From: |
Christoph Hellwig |
Subject: |
[Qemu-devel] [PATCH] sanitize ->bdrv_get_buffer / ->bdrv_put_buffer calling conventions |
Date: |
Tue, 7 Jul 2009 19:34:01 +0200 |
User-agent: |
Mutt/1.3.28i |
The VM state offset is an concept internal to the image format, it
doesn't even have to be a traditional linear offset. So change the
->bdrv_get_buffer / ->bdrv_put_buffer calling convention to always pass
a relative offset and add the VM state offset to it internally inside
the qcow2 code.
Signed-off-by: Christoph Hellwig <address@hidden>
Index: qemu/savevm.c
===================================================================
--- qemu.orig/savevm.c 2009-07-07 18:42:42.103269394 +0200
+++ qemu/savevm.c 2009-07-07 19:23:16.577363547 +0200
@@ -337,46 +337,28 @@ fail:
return NULL;
}
-typedef struct QEMUFileBdrv
-{
- BlockDriverState *bs;
- int64_t base_offset;
-} QEMUFileBdrv;
-
static int block_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
- QEMUFileBdrv *s = opaque;
- bdrv_put_buffer(s->bs, buf, s->base_offset + pos, size);
+ bdrv_put_buffer(opaque, buf, pos, size);
return size;
}
static int block_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size)
{
- QEMUFileBdrv *s = opaque;
- return bdrv_get_buffer(s->bs, buf, s->base_offset + pos, size);
+ return bdrv_get_buffer(opaque, buf, pos, size);
}
static int bdrv_fclose(void *opaque)
{
- QEMUFileBdrv *s = opaque;
- qemu_free(s);
return 0;
}
-static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int64_t offset, int
is_writable)
+static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
{
- QEMUFileBdrv *s;
-
- s = qemu_mallocz(sizeof(QEMUFileBdrv));
-
- s->bs = bs;
- s->base_offset = offset;
-
if (is_writable)
- return qemu_fopen_ops(s, block_put_buffer, NULL, bdrv_fclose, NULL,
NULL);
-
- return qemu_fopen_ops(s, NULL, block_get_buffer, bdrv_fclose, NULL, NULL);
+ return qemu_fopen_ops(bs, block_put_buffer, NULL, bdrv_fclose, NULL,
NULL);
+ return qemu_fopen_ops(bs, NULL, block_get_buffer, bdrv_fclose, NULL, NULL);
}
QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer,
@@ -1069,7 +1051,6 @@ void do_savevm(Monitor *mon, const char
BlockDriverState *bs, *bs1;
QEMUSnapshotInfo sn1, *sn = &sn1, old_sn1, *old_sn = &old_sn1;
int must_delete, ret, i;
- BlockDriverInfo bdi1, *bdi = &bdi1;
QEMUFile *f;
int saved_vm_running;
uint32_t vm_state_size;
@@ -1119,14 +1100,8 @@ void do_savevm(Monitor *mon, const char
#endif
sn->vm_clock_nsec = qemu_get_clock(vm_clock);
- if (bdrv_get_info(bs, bdi) < 0 || bdi->vm_state_offset <= 0) {
- monitor_printf(mon, "Device %s does not support VM state snapshots\n",
- bdrv_get_device_name(bs));
- goto the_end;
- }
-
/* save the VM state */
- f = qemu_fopen_bdrv(bs, bdi->vm_state_offset, 1);
+ f = qemu_fopen_bdrv(bs, 1);
if (!f) {
monitor_printf(mon, "Could not open VM state file\n");
goto the_end;
@@ -1170,7 +1145,6 @@ void do_savevm(Monitor *mon, const char
void do_loadvm(Monitor *mon, const char *name)
{
BlockDriverState *bs, *bs1;
- BlockDriverInfo bdi1, *bdi = &bdi1;
QEMUSnapshotInfo sn;
QEMUFile *f;
int i, ret;
@@ -1218,19 +1192,13 @@ void do_loadvm(Monitor *mon, const char
}
}
- if (bdrv_get_info(bs, bdi) < 0 || bdi->vm_state_offset <= 0) {
- monitor_printf(mon, "Device %s does not support VM state snapshots\n",
- bdrv_get_device_name(bs));
- return;
- }
-
/* Don't even try to load empty VM states */
ret = bdrv_snapshot_find(bs, &sn, name);
if ((ret >= 0) && (sn.vm_state_size == 0))
goto the_end;
/* restore the VM state */
- f = qemu_fopen_bdrv(bs, bdi->vm_state_offset, 0);
+ f = qemu_fopen_bdrv(bs, 0);
if (!f) {
monitor_printf(mon, "Could not open VM state file\n");
goto the_end;
diff --git a/block/qcow2.c b/block/qcow2.c
index 20c114b..6b8eefa 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -897,12 +897,16 @@ static void qcow_flush(BlockDriverState *bs)
bdrv_flush(s->hd);
}
+static int64_t qcow_vm_state_offset(BDRVQcowState *s)
+{
+ return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
+}
+
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVQcowState *s = bs->opaque;
bdi->cluster_size = s->cluster_size;
- bdi->vm_state_offset = (int64_t)s->l1_vm_state_index <<
- (s->cluster_bits + s->l2_bits);
+ bdi->vm_state_offset = qcow_vm_state_offset(s);
return 0;
}
@@ -935,10 +939,11 @@ static void dump_refcounts(BlockDriverState *bs)
static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
{
+ BDRVQcowState *s = bs->opaque;
int growable = bs->growable;
bs->growable = 1;
- bdrv_pwrite(bs, pos, buf, size);
+ bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
bs->growable = growable;
return size;
@@ -947,11 +952,12 @@ static int qcow_put_buffer(BlockDriverState *bs, const
uint8_t *buf,
static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf,
int64_t pos, int size)
{
+ BDRVQcowState *s = bs->opaque;
int growable = bs->growable;
int ret;
bs->growable = 1;
- ret = bdrv_pread(bs, pos, buf, size);
+ ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
bs->growable = growable;
return ret;
- [Qemu-devel] [PATCH] sanitize ->bdrv_get_buffer / ->bdrv_put_buffer calling conventions,
Christoph Hellwig <=