usb-mtp: replace the homebrew write with qemu_write_full

qemu_write_full takes care of partial blocking writes,
as in cases of larger file sizes

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Bandan Das <bsd@redhat.com>
Message-id: 20190129131908.27924-4-bsd@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 3 insertions, 11 deletions

diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 2ca25c9..f1d20fa 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -1632,24 +1632,16 @@ static char *utf16_to_str(uint8_t len, uint16_t *arr)
 /* Wrapper around write, returns 0 on failure */
 static uint64_t write_retry(int fd, void *buf, uint64_t size, off_t offset)
 {
-        uint64_t bytes_left = size, ret;
+        uint64_t ret = 0;
 
         if (lseek(fd, offset, SEEK_SET) < 0) {
             goto done;
         }
 
-        while (bytes_left > 0) {
-                ret = write(fd, buf, bytes_left);
-                if ((ret == -1) && (errno != EINTR || errno != EAGAIN ||
-                                    errno != EWOULDBLOCK)) {
-                        break;
-                }
-                bytes_left -= ret;
-                buf += ret;
-        }
+        ret = qemu_write_full(fd, buf, size);
 
 done:
-        return size - bytes_left;
+        return ret;
 }
 
 static void usb_mtp_update_object(MTPObject *parent, char *name)