From 320ba554d11f75c4c2753968505a1d3308b64dda Mon Sep 17 00:00:00 2001

From: Nir Soffer <nirsof@gmail.com>

Date: Mon, 25 Jun 2018 19:22:13 +0300

Subject: [PATCH] v2v: rvh-upload-plugin: Always read the response

Python manual warns[1]:

    Note that you must have read the whole response before you can send

    a new request to the server.

The reason for this warning is exposed only when the server is using

keep alive connections. When the response is not read, sending a new

request will fail with:

    httplib.ResponseNotReady

Even if Content-Length was 0 or the request has no content. The failure

looks like this when using --verbose:

nbdkit: python[1]: debug: zero count=33554432 offset=0 may_trim=1 fua=0

nbdkit: python[1]: debug: zero count=33554432 offset=33554432 may_trim=1 fua=0

nbdkit: python[1]: error: /home/nsoffer/src/libguestfs/tmp/rhvupload.Au2B5I/rhv-upload-plugin.py: zero: error: Request-sent

nbdkit: python[1]: debug: sending error reply: Input/output error

qemu-img: error writing zeroes at offset 0: Input/output error

Change all requests to read the whole response.

Tested with imageio patch supporting keep alive connections:

https://gerrit.ovirt.org/#/c/92296/

[1] https://docs.python.org/3.8/library/http.client.html#http.client.HTTPConnection.getresponse

(cherry picked from commit f4e0a8342dbeb2c779c76e1807a37b24a0c96feb)

---

 v2v/rhv-upload-plugin.py | 15 ++++++++++++++-

 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py

index 7c5084efd..2eec375f7 100644

--- a/v2v/rhv-upload-plugin.py

+++ b/v2v/rhv-upload-plugin.py

@@ -197,11 +197,13 @@ def get_options(h):

     http.endheaders()

     r = http.getresponse()

+    data = r.read()

+

     if r.status == 200:

         # New imageio never needs authentication.

         h['needs_auth'] = False

-        j = json.loads(r.read())

+        j = json.loads(data)

         h['can_zero'] = "zero" in j['features']

         h['can_trim'] = "trim" in j['features']

         h['can_flush'] = "flush" in j['features']

@@ -276,6 +278,7 @@ def pread(h, count, offset):

         request_failed(h, r,

                        "could not read sector offset %d size %d" %

                        (offset, count))

+

     return r.read()

 def pwrite(h, buf, offset):

@@ -302,6 +305,8 @@ def pwrite(h, buf, offset):

                        "could not write sector offset %d size %d" %

                        (offset, count))

+    r.read()

+

 def zero(h, count, offset, may_trim):

     http = h['http']

     transfer = h['transfer']

@@ -330,6 +335,8 @@ def zero(h, count, offset, may_trim):

                        "could not zero sector offset %d size %d" %

                        (offset, count))

+    r.read()

+

 def emulate_zero(h, count, offset):

     # qemu-img convert starts by trying to zero/trim the whole device.

     # Since we've just created a new disk it's safe to ignore these

@@ -357,6 +364,8 @@ def emulate_zero(h, count, offset):

                            "could not write zeroes offset %d size %d" %

                            (offset, count))

+        r.read()

+

 def trim(h, count, offset):

     http = h['http']

     transfer = h['transfer']

@@ -378,6 +387,8 @@ def trim(h, count, offset):

                        "could not trim sector offset %d size %d" %

                        (offset, count))

+    r.read()

+

 def flush(h):

     http = h['http']

     transfer = h['transfer']

@@ -394,6 +405,8 @@ def flush(h):

     if r.status != 200:

         request_failed(h, r, "could not flush")

+    r.read()

+

 def delete_disk_on_failure(h):

     disk_service = h['disk_service']

     disk_service.remove()

-- 

2.17.1