[PULL 1/3] file-posix: Handle `EINVAL` fallocate return value

[Kevin Wolf <kwolf@redhat.com>]

From: Antoine Damhet <antoine.damhet@blade-group.com>

The `detect-zeroes=unmap` option may issue unaligned
`FALLOC_FL_PUNCH_HOLE` requests, raw block devices can (and will) return
`EINVAL`, qemu should then write the zeroes to the blockdev instead of
issuing an `IO_ERROR`.

The problem can be reprodced like this:

$ qemu-io -c 'write -P 0 42 1234' --image-opts driver=host_device,filename=/dev/loop0,detect-zeroes=unmap
write failed: Invalid argument

Signed-off-by: Antoine Damhet <antoine.damhet@blade-group.com>
Message-Id: <20200717135603.51180-1-antoine.damhet@blade-group.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/file-posix.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 8cc39a1ef6..9a00d4190a 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1698,7 +1698,11 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
 #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
     int ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
                            aiocb->aio_offset, aiocb->aio_nbytes);
-    if (ret != -ENOTSUP) {
+    switch (ret) {
+    case -ENOTSUP:
+    case -EINVAL:
+        break;
+    default:
         return ret;
     }
 #endif
-- 
2.25.4