On 02/24/2015 04:43 AM, Max Reitz wrote:
On 2015-02-11 at 22:07, Wen Congyang wrote:
We connect to NBD server when starting block replication, so
the length is 0 before starting block replication.
Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
block/quorum.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/block/quorum.c b/block/quorum.c
index 5ed1ff8..e6aff5f 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -734,6 +734,11 @@ static int64_t quorum_getlength(BlockDriverState *bs)
if (value < 0) {
return value;
}
+
+ if (!value) {
+ continue;
+ }
+
if (value != result) {
return -EIO;
}
Hm, what do you think about some specific error value returned by your delayed
NBD implementation? Like -ENOTCONN or something like that? Then we'd be able to
discern a real 0-length block device from a not-yet-connected NBD server.
In my newest test, it cannot return -ENOTCONN, otherwise bdrv_open() will fail
when we open the child.
Here is the backtrace:
(gdb) bt
#0 bdrv_open_common (bs=0x5555563b2230, file=0x0, options=0x5555563b55a0,
flags=57410, drv=0x555555e90c00, errp=0x7fffffffd460) at block.c:1070
#1 0x000055555595ea72 in bdrv_open (pbs=0x7fffffffd5f8, filename=0x0,
reference=0x0, options=0x5555563b55a0, flags=57410, drv=0x555555e90c00,
errp=0x7fffffffd5e0) at block.c:1677
#2 0x000055555595e3a9 in bdrv_open_image (pbs=0x7fffffffd5f8, filename=0x0,
options=0x5555563a6730, bdref_key=0x555555a86b4c "file", flags=57410,
allow_none=true, errp=0x7fffffffd5e0) at block.c:1481
#3 0x000055555595e9ae in bdrv_open (pbs=0x555556388008, filename=0x0,
reference=0x0, options=0x5555563a6730, flags=8258, drv=0x555555e8b800,
errp=0x7fffffffd6b8) at block.c:1655
#4 0x00005555559b0058 in quorum_open (bs=0x55555639bd90,
options=0x55555639f100, flags=8258, errp=0x7fffffffd758) at block/quorum.c:1000
#5 0x000055555595d0b8 in bdrv_open_common (bs=0x55555639bd90, file=0x0,
options=0x55555639f100, flags=8258, drv=0x555555e8e5c0, errp=0x7fffffffd840) at
block.c:1045
#6 0x000055555595ea72 in bdrv_open (pbs=0x55555639bd50, filename=0x0,
reference=0x0, options=0x55555639f100, flags=8258, drv=0x555555e8e5c0,
errp=0x7fffffffdb70) at block.c:1677
#7 0x00005555559b3bd3 in blk_new_open (name=0x55555639bc60 "virtio0",
filename=0x0, reference=0x0, options=0x55555639a420, flags=66, errp=0x7fffffffdb70) at
block/block-backend.c:129
#8 0x0000555555754f78 in blockdev_init (file=0x0, bs_opts=0x55555639a420,
errp=0x7fffffffdb70) at blockdev.c:536
#9 0x0000555555755d90 in drive_new (all_opts=0x5555563777e0,
block_default_type=IF_IDE) at blockdev.c:971
#10 0x000055555576b1f0 in drive_init_func (opts=0x5555563777e0,
opaque=0x555556372b48) at vl.c:1104
#11 0x0000555555a1b019 in qemu_opts_foreach (list=0x555555e44060, func=0x55555576b1ba
<drive_init_func>, opaque=0x555556372b48, abort_on_failure=1) at
util/qemu-option.c:1059
#12 0x00005555557743dd in main (argc=25, argv=0x7fffffffe0c8,
envp=0x7fffffffe198) at vl.c:4191
refresh_total_sectors() will fail if we return -ENOTCONN.