qemu: domain: Allow forcing images to read-write in qemuDomainStorageSourceAccessAllow

In commit 76b9aba2ba6 I refactored how the function treats the readonly
flag which introduced a bug when we'd not allow to force read-write
state for an image.

This created problems with blockjobs where we need to temporarily
force images to have read-write permissions.

Rename QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_READ_ONLY to
QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_ONLY and also introduce
a complement QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_WRITE which
will allow to force write access.

https://bugzilla.redhat.com/show_bug.cgi?id=1717768

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index e521bd3982096f0bc14f4b582d40353d3530ffcd..2095191cde2512764fe1007b86baba6a3732e1c2 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -9305,12 +9305,14 @@ typedef enum {
     QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_REVOKE = 1 << 0,
     /* operate on full backing chain rather than single image */
     QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_CHAIN = 1 << 1,
-    /* force permissions to read-only when allowing */
-    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_READ_ONLY = 1 << 2,
+    /* force permissions to read-only/read-write when allowing */
+    /* currently does not properly work with QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_CHAIN */
+    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_ONLY = 1 << 2,
+    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_WRITE = 1 << 3,
     /* don't revoke permissions when modification has failed */
-    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_SKIP_REVOKE = 1 << 3,
+    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_SKIP_REVOKE = 1 << 4,
     /* VM already has access to the source and we are just modifying it */
-    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_MODIFY_ACCESS = 1 << 4,
+    QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_MODIFY_ACCESS = 1 << 5,
 } qemuDomainStorageSourceAccessFlags;
 
 
@@ -9344,9 +9346,12 @@ qemuDomainStorageSourceAccessModify(virQEMUDriverPtr driver,
     bool revoke_namespace = false;
     bool revoke_lockspace = false;
 
-    if (flags & QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_READ_ONLY)
+    if (flags & QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_ONLY)
         src->readonly = true;
 
+    if (flags & QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_WRITE)
+        src->readonly = false;
+
     /* just tear down the disk access */
     if (flags & QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_REVOKE) {
         virErrorPreserveLast(&orig_err);
@@ -9491,7 +9496,9 @@ qemuDomainStorageSourceAccessAllow(virQEMUDriverPtr driver,
     qemuDomainStorageSourceAccessFlags flags = QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_SKIP_REVOKE;
 
     if (readonly)
-        flags |= QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_READ_ONLY;
+        flags |= QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_ONLY;
+    else
+        flags |= QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_FORCE_READ_WRITE;
 
     if (!newSource)
         flags |= QEMU_DOMAIN_STORAGE_SOURCE_ACCESS_MODIFY_ACCESS;