ae23c9
From 8c14192b6417a5f07658c9434c10c4fb296574c8 Mon Sep 17 00:00:00 2001
ae23c9
From: Fam Zheng <famz@redhat.com>
ae23c9
Date: Fri, 29 Jun 2018 06:11:53 +0200
ae23c9
Subject: [PATCH 179/268] file-posix: Fix EINTR handling
ae23c9
ae23c9
RH-Author: Fam Zheng <famz@redhat.com>
ae23c9
Message-id: <20180629061153.12687-14-famz@redhat.com>
ae23c9
Patchwork-id: 81164
ae23c9
O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH v2 13/13] file-posix: Fix EINTR handling
ae23c9
Bugzilla: 1482537
ae23c9
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
ae23c9
RH-Acked-by: Max Reitz <mreitz@redhat.com>
ae23c9
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
ae23c9
ae23c9
EINTR should be checked against errno, not ret. While fixing the bug,
ae23c9
collect the branches with a switch block.
ae23c9
ae23c9
Also, change the return value from -ENOSTUP to -ENOSPC when the actual
ae23c9
issue is request range passes EOF, which should be distinguishable from
ae23c9
the case of error == ENOSYS by the caller, so that it could still retry
ae23c9
with other byte ranges, whereas it shouldn't retry anymore upon ENOSYS.
ae23c9
ae23c9
Signed-off-by: Fam Zheng <famz@redhat.com>
ae23c9
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
ae23c9
---
ae23c9
 block/file-posix.c | 17 +++++++++--------
ae23c9
 1 file changed, 9 insertions(+), 8 deletions(-)
ae23c9
ae23c9
diff --git a/block/file-posix.c b/block/file-posix.c
ae23c9
index 29ff699..0a9df5b 100644
ae23c9
--- a/block/file-posix.c
ae23c9
+++ b/block/file-posix.c
ae23c9
@@ -1449,20 +1449,21 @@ static ssize_t handle_aiocb_copy_range(RawPosixAIOData *aiocb)
ae23c9
         ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off,
ae23c9
                                       aiocb->aio_fd2, &out_off,
ae23c9
                                       bytes, 0);
ae23c9
-        if (ret == -EINTR) {
ae23c9
-            continue;
ae23c9
+        if (ret == 0) {
ae23c9
+            /* No progress (e.g. when beyond EOF), let the caller fall back to
ae23c9
+             * buffer I/O. */
ae23c9
+            return -ENOSPC;
ae23c9
         }
ae23c9
         if (ret < 0) {
ae23c9
-            if (errno == ENOSYS) {
ae23c9
+            switch (errno) {
ae23c9
+            case ENOSYS:
ae23c9
                 return -ENOTSUP;
ae23c9
-            } else {
ae23c9
+            case EINTR:
ae23c9
+                continue;
ae23c9
+            default:
ae23c9
                 return -errno;
ae23c9
             }
ae23c9
         }
ae23c9
-        if (!ret) {
ae23c9
-            /* No progress (e.g. when beyond EOF), fall back to buffer I/O. */
ae23c9
-            return -ENOTSUP;
ae23c9
-        }
ae23c9
         bytes -= ret;
ae23c9
     }
ae23c9
     return 0;
ae23c9
-- 
ae23c9
1.8.3.1
ae23c9