sdcard: direct I/O file access write buffer alignment

It is not enough to align the read buffer only, because
consequent writes might still fail with EINVAL. The write
buffer should be also aligned according to the write(2)
manual page.

Change-Id: I7547dec5208732c56f4466c1b0c88f36dabacf5b

1 files changed, 6 insertions, 0 deletions

diff --git a/sdcard/sdcard.c b/sdcard/sdcard.c
index 3bc8cd3f7..cb03316f4 100644
--- a/sdcard/sdcard.c
+++ b/sdcard/sdcard.c
@@ -1244,6 +1244,12 @@ static int handle_write(struct fuse* fuse, struct fuse_handler* handler,
     struct fuse_write_out out;
     struct handle *h = id_to_ptr(req->fh);
     int res;
+    __u8 aligned_buffer[req->size] __attribute__((__aligned__(PAGESIZE)));
+    
+    if (req->flags & O_DIRECT) {
+        memcpy(aligned_buffer, buffer, req->size);
+        buffer = (const __u8*) aligned_buffer;
+    }
 
     TRACE("[%d] WRITE %p(%d) %u@%llu\n", handler->token,
             h, h->fd, req->size, req->offset);