Catch the case where size= is less than the minimum block size

Fio will currently just attempt to start and immediately exit,
with no clue as to what went wrong. The behaviour is correct
in the sense that there's nothing to output, but it can be a
little confusing.

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

diff --git a/fio.h b/fio.h
index ebf6309b530f3a84f6b2cda5d9a841f70fde4488..5438b768da8f781d7f1bd19b4c955de89039b39a 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -535,6 +535,14 @@ static inline unsigned int td_max_bs(struct thread_data *td)
        return max(td->o.max_bs[DDIR_TRIM], max_bs);
 }
 
+static inline unsigned int td_min_bs(struct thread_data *td)
+{
+       unsigned int min_bs;
+
+       min_bs = min(td->o.min_bs[DDIR_READ], td->o.min_bs[DDIR_WRITE]);
+       return min(td->o.min_bs[DDIR_TRIM], min_bs);
+}
+
 static inline int is_power_of_2(unsigned int val)
 {
        return (val != 0 && ((val & (val - 1)) == 0));

diff --git a/init.c b/init.c
index b330925c0067e856d3e9ddbda94d42013139bf45..aba7671c1402ff953dc5549e5303b0b9954c2193 100644 (file)
--- a/init.c
+++ b/init.c
@@ -621,6 +621,14 @@ static int fixup_options(struct thread_data *td)
        if (td->o.random_distribution != FIO_RAND_DIST_RANDOM)
                td->o.norandommap = 1;
 
+       /*
+        * If size is set but less than the min block size, complain
+        */
+       if (o->size && o->size < td_min_bs(td)) {
+               log_err("fio: size too small, must be larger than the IO size: %llu\n", (unsigned long long) o->size);
+               ret = 1;
+       }
+
        return ret;
 }