diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2019-07-29 12:45:14 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2019-07-30 12:25:43 +0200 |
| commit | 2b23f28639c9ed3d4cdb1262b3e41b6b81be5e0b (patch) | |
| tree | 863ffb0e25adea0678d8c37860ae143243df47fb | |
| parent | 251071e0c0a0121e46fb1cc9c7a7fffba8dbbcd4 (diff) | |
block/copy-on-read: Fix permissions for inactive node
The copy-on-read drive must not request the WRITE_UNCHANGED permission
for its child if the node is inactive, otherwise starting a migration
destination with -incoming will fail because the child cannot provide
write access yet:
qemu-system-x86_64: -blockdev copy-on-read,file=img,node-name=cor: Block node is read-only
Earlier QEMU versions additionally ran into an abort() on the migration
source side: bdrv_inactivate_recurse() failed to update permissions.
This is silently ignored today because it was only supposed to loosen
restrictions. This is the symptom that was originally reported here:
https://bugzilla.redhat.com/show_bug.cgi?id=1733022
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
| -rw-r--r-- | block/copy-on-read.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/block/copy-on-read.c b/block/copy-on-read.c index 22f24fd0db..6631f30205 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -56,16 +56,14 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChild *c, uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) { - if (c == NULL) { - *nperm = (perm & PERM_PASSTHROUGH) | BLK_PERM_WRITE_UNCHANGED; - *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED; - return; - } + *nperm = perm & PERM_PASSTHROUGH; + *nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED; - *nperm = (perm & PERM_PASSTHROUGH) | - (c->perm & PERM_UNCHANGED); - *nshared = (shared & PERM_PASSTHROUGH) | - (c->shared_perm & PERM_UNCHANGED); + /* We must not request write permissions for an inactive node, the child + * cannot provide it. */ + if (!(bs->open_flags & BDRV_O_INACTIVE)) { + *nperm |= BLK_PERM_WRITE_UNCHANGED; + } } |