[Qemu-devel] [PATCH v4 13/21] raw-posix: Handle failure for potentially large allocations

[Kevin Wolf <kwolf@redhat.com>]

Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the raw-posix block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/raw-posix.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index dacf4fb..3001b13 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -778,7 +778,11 @@ static ssize_t handle_aiocb_rw(RawPosixAIOData *aiocb)
      * Ok, we have to do it the hard way, copy all segments into
      * a single aligned buffer.
      */
-    buf = qemu_blockalign(aiocb->bs, aiocb->aio_nbytes);
+    buf = qemu_try_blockalign(aiocb->bs, aiocb->aio_nbytes);
+    if (buf == NULL) {
+        return -ENOMEM;
+    }
+
     if (aiocb->aio_type & QEMU_AIO_WRITE) {
         char *p = buf;
         int i;
-- 
1.8.3.1