[Qemu-block] [PATCH 1/6] file-posix: Fix EINTR handling

[Fam Zheng]

EINTR should be checked against errno, not ret. While fixing the bug,
collecting the branches with a switch block.

Signed-off-by: Fam Zheng <address@hidden>
---
 block/file-posix.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 513d371bb1..c6dae38f94 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1473,20 +1473,20 @@ static ssize_t handle_aiocb_copy_range(RawPosixAIOData 
*aiocb)
         ssize_t ret = copy_file_range(aiocb->aio_fildes, &in_off,
                                       aiocb->aio_fd2, &out_off,
                                       bytes, 0);
-        if (ret == -EINTR) {
-            continue;
-        }
-        if (ret < 0) {
-            if (errno == ENOSYS) {
+        if (ret <= 0) {
+            switch (errno) {
+            case 0:
+                /* No progress (e.g. when beyond EOF), let the caller fall back
+                 * to buffer I/O. */
+                /* fall through */
+            case ENOSYS:
                 return -ENOTSUP;
-            } else {
+            case EINTR:
+                continue;
+            default:
                 return -errno;
             }
         }
-        if (!ret) {
-            /* No progress (e.g. when beyond EOF), fall back to buffer I/O. */
-            return -ENOTSUP;
-        }
         bytes -= ret;
     }
     return 0;
-- 
2.17.0