Daniel P. Berrange writes ("Re: [Xen-devel] [PATCH] ioemu block device extent
checks"):
> The qcow driver though calls back into
> the raw driver for performing I/O on its underlying file. The qcow
> driver relies on this file being grow-on-demand for purposes of allocating
> new qcow sectors. The safety checks cause this allocation to fail and
> it all goes downhill from there :-(
Oh dear. (I'm a bit surprised that it's taken this long to spot!)
Here is a patch for xen-unstable which I think will fix it. Could you
give it a quick spin, if you have a suitable test setup ?
Sadly it's rather more intrusive than ideal, since it needs all of the
drivers which are going to extend files via their parents to announce
this, and a couple of bits of necessary infrastructure needed adding.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
diff -r 757cd7bb5e35 tools/ioemu/block-qcow.c
--- a/tools/ioemu/block-qcow.c Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block-qcow.c Wed Feb 27 11:09:56 2008 +0000
@@ -95,7 +95,7 @@ static int qcow_open(BlockDriverState *b
int len, i, shift, ret;
QCowHeader header;
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
diff -r 757cd7bb5e35 tools/ioemu/block-qcow2.c
--- a/tools/ioemu/block-qcow2.c Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block-qcow2.c Wed Feb 27 11:09:56 2008 +0000
@@ -191,7 +191,7 @@ static int qcow_open(BlockDriverState *b
int len, i, shift, ret;
QCowHeader header;
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
diff -r 757cd7bb5e35 tools/ioemu/block-raw.c
--- a/tools/ioemu/block-raw.c Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block-raw.c Wed Feb 27 11:12:28 2008 +0000
@@ -1489,5 +1489,7 @@ BlockDriver bdrv_host_device = {
.bdrv_pread = raw_pread,
.bdrv_pwrite = raw_pwrite,
.bdrv_getlength = raw_getlength,
+
+ .bdrv_flags = BLOCK_DRIVER_FLAG_EXTENDABLE
};
#endif /* _WIN32 */
diff -r 757cd7bb5e35 tools/ioemu/block-vmdk.c
--- a/tools/ioemu/block-vmdk.c Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block-vmdk.c Wed Feb 27 11:10:02 2008 +0000
@@ -352,7 +352,7 @@ static int vmdk_open(BlockDriverState *b
uint32_t magic;
int l1_size, i, ret;
- ret = bdrv_file_open(&s->hd, filename, flags);
+ ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE);
if (ret < 0)
return ret;
if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))
diff -r 757cd7bb5e35 tools/ioemu/block.c
--- a/tools/ioemu/block.c Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block.c Wed Feb 27 11:13:57 2008 +0000
@@ -123,20 +123,23 @@ static int bdrv_rw_badreq_sectors(BlockD
static int bdrv_rw_badreq_sectors(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
- return
+ return (
nb_sectors < 0 ||
nb_sectors > bs->total_sectors ||
- sector_num > bs->total_sectors - nb_sectors;
+ sector_num > bs->total_sectors - nb_sectors
+ ) && !bs->extendable;
}
static int bdrv_rw_badreq_bytes(BlockDriverState *bs,
int64_t offset, int count)
{
int64_t size = bs->total_sectors << SECTOR_BITS;
- return
+ return (
count < 0 ||
count > size ||
- offset > size - count;
+ offset > size - count
+ ) && !bs->extendable;
+
}
void bdrv_register(BlockDriver *bdrv)
@@ -347,6 +350,12 @@ int bdrv_open2(BlockDriverState *bs, con
bs->is_temporary = 0;
bs->encrypted = 0;
+ if (flags & BDRV_O_EXTENDABLE) {
+ if (!(drv->bdrv_flags & BLOCK_DRIVER_FLAG_EXTENDABLE))
+ return -ENOSYS;
+ bs->extendable = 1;
+ }
+
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
int64_t total_size;
diff -r 757cd7bb5e35 tools/ioemu/block_int.h
--- a/tools/ioemu/block_int.h Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/block_int.h Wed Feb 27 11:11:39 2008 +0000
@@ -23,6 +23,8 @@
*/
#ifndef BLOCK_INT_H
#define BLOCK_INT_H
+
+#define BLOCK_DRIVER_FLAG_EXTENDABLE 0x0001u
struct BlockDriver {
const char *format_name;
@@ -76,6 +78,7 @@ struct BlockDriver {
int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
+ unsigned bdrv_flags;
BlockDriverAIOCB *free_aiocb;
struct BlockDriver *next;
};
@@ -87,6 +90,7 @@ struct BlockDriverState {
int removable; /* if true, the media can be removed */
int locked; /* if true, the media cannot temporarily be ejected */
int encrypted; /* if true, the media is encrypted */
+ int extendable;/* if true, we may write out of original range */
/* event callback when inserting/removing */
void (*change_cb)(void *opaque);
void *change_opaque;
diff -r 757cd7bb5e35 tools/ioemu/vl.h
--- a/tools/ioemu/vl.h Fri Feb 22 16:49:56 2008 +0000
+++ b/tools/ioemu/vl.h Wed Feb 27 11:12:03 2008 +0000
@@ -614,6 +614,8 @@ typedef struct QEMUSnapshotInfo {
use a disk image format on top of
it (default for
bdrv_file_open()) */
+#define BDRV_O_EXTENDABLE 0x0080 /* allow writes out of original size range;
+ only effective for some drivers */
void bdrv_init(void);
BlockDriver *bdrv_find_format(const char *format_name);
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
Home