zbd: Fix I/O direction adjustment step for random read/write

Commit fb0259fb ("zbd: Ensure first I/O is write for random read/write to
sequential zones") introduced a step to change direction of io_u from
read to write when that is the first I/O of the random read/write
workload to zoned block devices. However, such direction adjustment
results in inconsistent I/O length when read block size and write block
size are different.

To avoid the inconsistency between I/O direction and I/O length,
adjust the I/O direction before the I/O length is set. Move the step
from zbd_adjust_block() to set_rw_ddir(). To minimize changes in
set_rw_ddir(), introduce zbd_adjust_ddir() helper function.

Fixes: fb0259fb ("zbd: Ensure first I/O is write for random read/write to sequential zones")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_u.c b/io_u.c
index 5d62a76cb5a72c81ffd0cfee35ace6bf3ee162e6..18e94617f08fd8677d9c839e8a5f71a58c85e99f 100644 (file)
--- a/io_u.c
+++ b/io_u.c
@@ -746,6 +746,8 @@ static void set_rw_ddir(struct thread_data *td, struct io_u *io_u)
 {
        enum fio_ddir ddir = get_rw_ddir(td);
 
+       ddir = zbd_adjust_ddir(td, io_u, ddir);
+
        if (td_trimwrite(td)) {
                struct fio_file *f = io_u->file;
                if (f->last_pos[DDIR_WRITE] == f->last_pos[DDIR_TRIM])

diff --git a/zbd.c b/zbd.c
index de0c5bf4fe0d425583dc9ed203b8bea6a5cd7f42..8dc3c39792931803b07d714ec222b1807c353102 100644 (file)
--- a/zbd.c
+++ b/zbd.c
@@ -1331,6 +1331,36 @@ void setup_zbd_zone_mode(struct thread_data *td, struct io_u *io_u)
        }
 }
 
+/**
+ * zbd_adjust_ddir - Adjust an I/O direction for zonedmode=zbd.
+ *
+ * @td: FIO thread data.
+ * @io_u: FIO I/O unit.
+ * @ddir: I/O direction before adjustment.
+ *
+ * Return adjusted I/O direction.
+ */
+enum fio_ddir zbd_adjust_ddir(struct thread_data *td, struct io_u *io_u,
+                             enum fio_ddir ddir)
+{
+       /*
+        * In case read direction is chosen for the first random I/O, fio with
+        * zonemode=zbd stops because no data can be read from zoned block
+        * devices with all empty zones. Overwrite the first I/O direction as
+        * write to make sure data to read exists.
+        */
+       if (td->o.zone_mode != ZONE_MODE_ZBD ||
+           ddir != DDIR_READ ||
+           !td_rw(td))
+               return ddir;
+
+       if (io_u->file->zbd_info->sectors_with_data ||
+           td->o.read_beyond_wp)
+               return DDIR_READ;
+
+       return DDIR_WRITE;
+}
+
 /**
  * zbd_adjust_block - adjust the offset and length as necessary for ZBD drives
  * @td: FIO thread data.
@@ -1364,16 +1394,6 @@ enum io_u_action zbd_adjust_block(struct thread_data *td, struct io_u *io_u)
        if (!zbd_zone_swr(zb))
                return io_u_accept;
 
-       /*
-        * In case read direction is chosen for the first random I/O, fio with
-        * zonemode=zbd stops because no data can be read from zoned block
-        * devices with all empty zones. Overwrite the first I/O direction as
-        * write to make sure data to read exists.
-        */
-       if (td_rw(td) && !f->zbd_info->sectors_with_data
-           && !td->o.read_beyond_wp)
-               io_u->ddir = DDIR_WRITE;
-
        /*
         * Accept the I/O offset for reads if reading beyond the write pointer
         * is enabled.

diff --git a/zbd.h b/zbd.h
index 4eaf902e3e10426cdf75af1f3a3c4b4749fc8a46..5a66039967e0b4c4628c37857ee4c283f78fb647 100644 (file)
--- a/zbd.h
+++ b/zbd.h
@@ -82,6 +82,8 @@ int zbd_init(struct thread_data *td);
 void zbd_file_reset(struct thread_data *td, struct fio_file *f);
 bool zbd_unaligned_write(int error_code);
 void setup_zbd_zone_mode(struct thread_data *td, struct io_u *io_u);
+enum fio_ddir zbd_adjust_ddir(struct thread_data *td, struct io_u *io_u,
+                             enum fio_ddir ddir);
 enum io_u_action zbd_adjust_block(struct thread_data *td, struct io_u *io_u);
 char *zbd_write_status(const struct thread_stat *ts);