block/iscsi: enable filename option and parsing

When enabling option parsing and blockdev-add for iscsi, we removed the
'filename' option.  Unfortunately, this was a bit optimistic, as
previous versions of QEMU allowed the use of the option in backing
filenames via json.  This means that without parsing this option, we
cannot open existing images that used to work fine.

See bug: https://bugzilla.redhat.com/show_bug.cgi?id=1457088

Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: 0789ab6c32814ab4b6896707d378804bd4424c65.1497444637.git.jcody@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/block/iscsi.c b/block/iscsi.c
index 5daa201181..b5f7a228b9 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1732,6 +1732,10 @@ static QemuOptsList runtime_opts = {
             .name = "timeout",
             .type = QEMU_OPT_NUMBER,
         },
+        {
+            .name = "filename",
+            .type = QEMU_OPT_STRING,
+        },
         { /* end of list */ }
     },
 };
@@ -1747,12 +1751,27 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
     char *initiator_name = NULL;
     QemuOpts *opts;
     Error *local_err = NULL;
-    const char *transport_name, *portal, *target;
+    const char *transport_name, *portal, *target, *filename;
 #if LIBISCSI_API_VERSION >= (20160603)
     enum iscsi_transport_type transport;
 #endif
     int i, ret = 0, timeout = 0, lun;
 
+    /* If we are given a filename, parse the filename, with precedence given to
+     * filename encoded options */
+    filename = qdict_get_try_str(options, "filename");
+    if (filename) {
+        error_report("Warning: 'filename' option specified. "
+                      "This is an unsupported option, and may be deprecated "
+                      "in the future");
+        iscsi_parse_filename(filename, options, &local_err);
+        if (local_err) {
+            ret = -EINVAL;
+            error_propagate(errp, local_err);
+            goto exit;
+        }
+    }
+
     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
     qemu_opts_absorb_qdict(opts, options, &local_err);
     if (local_err) {
@@ -1967,6 +1986,7 @@ out:
         }
         memset(iscsilun, 0, sizeof(IscsiLun));
     }
+exit:
     return ret;
 }