[PATCH 5/5] do not apply: Revert "nbd-client: Work around server BLOCK_STATUS misalignment at EOF"

[Eric Blake <eblake@redhat.com>]

This reverts commit 737d3f524481bb2ef68d3eba1caa636ff143e16a.

This is intended only for testing purposes: if you apply this without
the rest of the series, iotest 241 no longer benefits from the client
side working around server non-compliance.

---
 block/nbd.c | 30 ++++--------------------------
 1 file changed, 4 insertions(+), 26 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index c26dc5a54f52..34c91f68e150 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -937,36 +937,14 @@ static int nbd_parse_blockstatus_payload(BDRVNBDState *s,
     extent->length = payload_advance32(&payload);
     extent->flags = payload_advance32(&payload);

-    if (extent->length == 0) {
+    if (extent->length == 0 ||
+        (s->info.min_block && !QEMU_IS_ALIGNED(extent->length,
+                                               s->info.min_block))) {
         error_setg(errp, "Protocol error: server sent status chunk with "
-                   "zero length");
+                   "invalid length");
         return -EINVAL;
     }

-    /*
-     * A server sending unaligned block status is in violation of the
-     * protocol, but as qemu-nbd 3.1 is such a server (at least for
-     * POSIX files that are not a multiple of 512 bytes, since qemu
-     * rounds files up to 512-byte multiples but lseek(SEEK_HOLE)
-     * still sees an implicit hole beyond the real EOF), it's nicer to
-     * work around the misbehaving server. If the request included
-     * more than the final unaligned block, truncate it back to an
-     * aligned result; if the request was only the final block, round
-     * up to the full block and change the status to fully-allocated
-     * (always a safe status, even if it loses information).
-     */
-    if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length,
-                                                   s->info.min_block)) {
-        trace_nbd_parse_blockstatus_compliance("extent length is unaligned");
-        if (extent->length > s->info.min_block) {
-            extent->length = QEMU_ALIGN_DOWN(extent->length,
-                                             s->info.min_block);
-        } else {
-            extent->length = s->info.min_block;
-            extent->flags = 0;
-        }
-    }
-
     /*
      * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have
      * sent us any more than one extent, nor should it have included
-- 
2.30.1