Fix refill buffers overwriting verify data

[fio.git] / engines / splice.c

diff --git a/engines/splice.c b/engines/splice.c
index 2344fddd3be30b2192f4ea1e4d1b921a8baebd70..5a288b5532c013d7e3cb8d58a6c131b76c488d82 100644 (file)
--- a/engines/splice.c
+++ b/engines/splice.c
@@ -20,6 +20,7 @@
 struct spliceio_data {
        int pipe[2];
        int vmsplice_to_user;
+       int vmsplice_to_user_map;
 };
 
 /*
@@ -76,20 +77,28 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
        struct spliceio_data *sd = td->io_ops->data;
        struct fio_file *f = io_u->file;
        struct iovec iov;
-       int ret = 0 , buflen, mmap_len;
+       int ret , buflen, mmap_len;
        off_t offset;
        void *p, *map;
 
+restart:
+       ret = 0;
        offset = io_u->offset;
        mmap_len = buflen = io_u->xfer_buflen;
 
-       map = mmap(io_u->xfer_buf, buflen, PROT_READ, MAP_PRIVATE|OS_MAP_ANON, 0, 0);
-       if (map == MAP_FAILED) {
-               td_verror(td, errno, "mmap io_u");
-               return -1;
+       if (sd->vmsplice_to_user_map) {
+               map = mmap(io_u->xfer_buf, buflen, PROT_READ, MAP_PRIVATE|OS_MAP_ANON, 0, 0);
+               if (map == MAP_FAILED) {
+                       td_verror(td, errno, "mmap io_u");
+                       return -1;
+               }
+
+               p = map;
+       } else {
+               map = NULL;
+               p = io_u->xfer_buf;
        }
 
-       p = map;
        while (buflen) {
                int this_len = buflen;
                int flags = 0;
@@ -116,6 +125,15 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
                while (iov.iov_len) {
                        ret = vmsplice(sd->pipe[0], &iov, 1, SPLICE_F_MOVE);
                        if (ret < 0) {
+                               if (errno == EFAULT && sd->vmsplice_to_user_map) {
+                                       sd->vmsplice_to_user_map = 0;
+                                       munmap(map, mmap_len);
+                                       goto restart;
+                               }
+                               if (errno == EBADF) {
+                                       ret = -EBADF;
+                                       break;
+                               }
                                td_verror(td, errno, "vmsplice");
                                break;
                        } else if (!ret) {
@@ -131,7 +149,7 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
                        break;
        }
 
-       if (munmap(map, mmap_len) < 0) {
+       if (sd->vmsplice_to_user_map && munmap(map, mmap_len) < 0) {
                td_verror(td, errno, "munnap io_u");
                return -1;
        }
@@ -247,6 +265,12 @@ static int fio_spliceio_init(struct thread_data *td)
         */
        sd->vmsplice_to_user = 1;
 
+       /*
+        * Works with "real" vmsplice to user, eg mapping pages directly.
+        * Reset if we fail.
+        */
+       sd->vmsplice_to_user_map = 1;
+
        /*
         * And if vmsplice_to_user works, we definitely need aligned
         * buffers. Just set ->odirect to force that.