Fix batch mismatch for verifies

If we set verify_backlog=32, we expect 32 writes followed by 32
reads that verify the written data. But if we fail getting a
verify io_u, then we may decrement the batch counter when we should
not. The result is that we write 32, read 32, write 1, read 1, repeat.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_u.c b/io_u.c
index 2deb5c7216aea5e02c66cf8237fb7648fc3a2dd2..06ca711b57e4ec9a18bf39d75acf2c98ce13740e 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -1117,10 +1117,9 @@ static int check_get_verify(struct thread_data *td, struct io_u *io_u)
        if (td->o.verify_backlog && td->io_hist_len) {
                int get_verify = 0;
 
-               if (td->verify_batch) {
-                       td->verify_batch--;
+               if (td->verify_batch)
                        get_verify = 1;
-               } else if (!(td->io_hist_len % td->o.verify_backlog) &&
+               else if (!(td->io_hist_len % td->o.verify_backlog) &&
                         td->last_ddir != DDIR_READ) {
                        td->verify_batch = td->o.verify_batch;
                        if (!td->verify_batch)
@@ -1128,8 +1127,10 @@ static int check_get_verify(struct thread_data *td, struct io_u *io_u)
                        get_verify = 1;
                }
 
-               if (get_verify && !get_next_verify(td, io_u))
+               if (get_verify && !get_next_verify(td, io_u)) {
+                       td->verify_batch--;
                        return 1;
+               }
        }
 
        return 0;