Optimize the code that copies strings

[fio.git] / engines / sg.c

diff --git a/engines/sg.c b/engines/sg.c
index bf437c8d6f2c3fbba3d51d8ce7e3a4b0a834c6a3..a1a6de4ce248dd680dc9d2f709479422de24b6de 100644 (file)
--- a/engines/sg.c
+++ b/engines/sg.c
@@ -424,7 +424,8 @@ static enum fio_q_status fio_sgio_ioctl_doio(struct thread_data *td,
        return FIO_Q_COMPLETED;
 }
 
-static enum fio_q_status fio_sgio_rw_doio(struct fio_file *f,
+static enum fio_q_status fio_sgio_rw_doio(struct thread_data *td,
+                                         struct fio_file *f,
                                          struct io_u *io_u, int do_sync)
 {
        struct sg_io_hdr *hdr = &io_u->hdr;
@@ -435,13 +436,32 @@ static enum fio_q_status fio_sgio_rw_doio(struct fio_file *f,
                return ret;
 
        if (do_sync) {
-               ret = read(f->fd, hdr, sizeof(*hdr));
-               if (ret < 0)
-                       return ret;
+               /*
+                * We can't just read back the first command that completes
+                * and assume it's the one we need, it could be any command
+                * that is inflight.
+                */
+               do {
+                       struct io_u *__io_u;
 
-               /* record if an io error occurred */
-               if (hdr->info & SG_INFO_CHECK)
-                       io_u->error = EIO;
+                       ret = read(f->fd, hdr, sizeof(*hdr));
+                       if (ret < 0)
+                               return ret;
+
+                       __io_u = hdr->usr_ptr;
+
+                       /* record if an io error occurred */
+                       if (hdr->info & SG_INFO_CHECK)
+                               __io_u->error = EIO;
+
+                       if (__io_u == io_u)
+                               break;
+
+                       if (io_u_sync_complete(td, __io_u)) {
+                               ret = -1;
+                               break;
+                       }
+               } while (1);
 
                return FIO_Q_COMPLETED;
        }
@@ -457,10 +477,11 @@ static enum fio_q_status fio_sgio_doio(struct thread_data *td,
 
        if (f->filetype == FIO_TYPE_BLOCK) {
                ret = fio_sgio_ioctl_doio(td, f, io_u);
-               td_verror(td, io_u->error, __func__);
+               if (io_u->error)
+                       td_verror(td, io_u->error, __func__);
        } else {
-               ret = fio_sgio_rw_doio(f, io_u, do_sync);
-               if (do_sync)
+               ret = fio_sgio_rw_doio(td, f, io_u, do_sync);
+               if (io_u->error && do_sync)
                        td_verror(td, io_u->error, __func__);
        }
 
@@ -678,7 +699,7 @@ static int fio_sgio_commit(struct thread_data *td)
 
        sd->current_queue = -1;
 
-       ret = fio_sgio_rw_doio(io_u->file, io_u, 0);
+       ret = fio_sgio_rw_doio(td, io_u->file, io_u, 0);
 
        if (ret < 0 || hdr->status) {
                int error;
@@ -1160,8 +1181,8 @@ static char *fio_sgio_errdetails(struct io_u *io_u)
        }
 
        if (!(hdr->info & SG_INFO_CHECK) && !strlen(msg))
-               strncpy(msg, "SG Driver did not report a Host, Driver or Device check",
-                       MAXERRDETAIL - 1);
+               snprintf(msg, MAXERRDETAIL, "%s",
+                        "SG Driver did not report a Host, Driver or Device check");
 
        return msg;
 }