Fix refill buffers overwriting verify data

[fio.git] / engines / splice.c

diff --git a/engines/splice.c b/engines/splice.c
index 9386983c5daae1b899e491ae434ba0f4d26e1ed0..5a288b5532c013d7e3cb8d58a6c131b76c488d82 100644 (file)
--- a/engines/splice.c
+++ b/engines/splice.c
@@ -11,6 +11,7 @@
 #include <errno.h>
 #include <assert.h>
 #include <sys/poll.h>
+#include <sys/mman.h>
 
 #include "../fio.h"
 
@@ -19,6 +20,7 @@
 struct spliceio_data {
        int pipe[2];
        int vmsplice_to_user;
+       int vmsplice_to_user_map;
 };
 
 /*
@@ -75,25 +77,44 @@ 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, buflen;
+       int ret , buflen, mmap_len;
        off_t offset;
-       void *p;
+       void *p, *map;
 
+restart:
+       ret = 0;
        offset = io_u->offset;
-       buflen = io_u->xfer_buflen;
-       p = io_u->xfer_buf;
+       mmap_len = buflen = io_u->xfer_buflen;
+
+       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;
+       }
+
        while (buflen) {
                int this_len = buflen;
+               int flags = 0;
 
-               if (this_len > SPLICE_DEF_SIZE)
+               if (this_len > SPLICE_DEF_SIZE) {
                        this_len = SPLICE_DEF_SIZE;
+                       flags = SPLICE_F_MORE;
+               }
 
-               ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE);
+               ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len,flags);
                if (ret < 0) {
                        if (errno == ENODATA || errno == EAGAIN)
                                continue;
 
-                       return -errno;
+                       td_verror(td, errno, "splice-from-fd");
+                       break;
                }
 
                buflen -= ret;
@@ -103,15 +124,37 @@ 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)
-                               return -errno;
-                       else if (!ret)
-                               return -ENODATA;
+                       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) {
+                               td_verror(td, ENODATA, "vmsplice");
+                               ret = -1;
+                               break;
+                       }
 
                        iov.iov_len -= ret;
                        iov.iov_base += ret;
                }
+               if (ret < 0)
+                       break;
+       }
+
+       if (sd->vmsplice_to_user_map && munmap(map, mmap_len) < 0) {
+               td_verror(td, errno, "munnap io_u");
+               return -1;
        }
+       if (ret < 0)
+               return ret;
 
        return io_u->xfer_buflen;
 }
@@ -160,6 +203,8 @@ static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u)
        struct spliceio_data *sd = td->io_ops->data;
        int ret;
 
+       fio_ro_check(td, io_u);
+
        if (io_u->ddir == DDIR_READ) {
                if (sd->vmsplice_to_user) {
                        ret = fio_splice_read(td, io_u);
@@ -220,6 +265,19 @@ 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.
+        */
+       if (td_read(td))
+               td->o.odirect = 1;
+
        td->io_ops->data = sd;
        return 0;
 }