qmp: dump-guest-memory: don't spin if non-blocking fd would block
fd_write_vmcore() will indefinitely spin for a non-blocking
file-descriptor that would block. However, if the fd is non-blocking,
how does it make sense to spin?
Change this behavior to return an error instead.
Note that this can only happen with an fd provided by a management
application. The fd opened internally by dump-guest-memory is blocking.
While there, also fix 'writen_size' variable name.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
diff --git a/dump.c b/dump.c
index 1a3c716..6b7c127 100644
--- a/dump.c
+++ b/dump.c
@@ -100,18 +100,11 @@
static int fd_write_vmcore(void *buf, size_t size, void *opaque)
{
DumpState *s = opaque;
- int fd = s->fd;
- size_t writen_size;
+ size_t written_size;
- /* The fd may be passed from user, and it can be non-blocked */
- while (size) {
- writen_size = qemu_write_full(fd, buf, size);
- if (writen_size != size && errno != EAGAIN) {
- return -1;
- }
-
- buf += writen_size;
- size -= writen_size;
+ written_size = qemu_write_full(s->fd, buf, size);
+ if (written_size != size) {
+ return -1;
}
return 0;
