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Fix savevm after BDRV_FILE size enforcement

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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
This commit is contained in:
aliguori 2009-04-05 19:10:55 +00:00
parent 8185d2c9a2
commit 178e08a58f
5 changed files with 64 additions and 6 deletions
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28
block-qcow2.c
View File

@ -2721,6 +2721,31 @@ static void dump_refcounts(BlockDriverState *bs)
#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 @@ BlockDriver bdrv_qcow2 = {
.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,
};

20
block.c
View File

@ -1146,6 +1146,26 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
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 */

5
block.h
View File

@ -178,4 +178,9 @@ void path_combine(char *dest, int dest_size,
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

5
block_int.h
View File

@ -78,6 +78,11 @@ struct BlockDriver {
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);

12
savevm.c
View File

@ -310,18 +310,18 @@ typedef struct QEMUFileBdrv
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 @@ static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int64_t offset, int is_wr
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,