zbd: Fix partition block device handling

For fio to correctly handle the zonemode=zbd mode with partitions of
zoned block devices, the partition block device file must be identified
as a zoned disk. However, partition block device files do not have
a zoned sysfs file. This patch allows a correct identification of the
device file zone model by accessing the sysfs "zoned" file of the
holder disk for partition devices.

Change get_zbd_model() function to resolve the symbolic link to the
sysfs path to obtain the canonical sysfs path. The canonical sysfs
path of a partition device includes both of the holder device name and
the partition device name. If the given device is a partition device,
cut the partition device name in the canonical sysfs path to access
the "zoned" file in the holder device sysfs path.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/zbd.c b/zbd.c
index 8acda1f62f32bcf38c458f3eb67110e54262da7c..9b603b97b18344b5e17baf31f199371a8c5f11ff 100644 (file)
--- a/zbd.c
+++ b/zbd.c
@@ -228,12 +228,45 @@ static enum blk_zoned_model get_zbd_model(const char *file_name)
        char *zoned_attr_path = NULL;
        char *model_str = NULL;
        struct stat statbuf;
+       char *sys_devno_path = NULL;
+       char *part_attr_path = NULL;
+       char *part_str = NULL;
+       char sys_path[PATH_MAX];
+       ssize_t sz;
+       char *delim = NULL;
 
        if (stat(file_name, &statbuf) < 0)
                goto out;
-       if (asprintf(&zoned_attr_path, "/sys/dev/block/%d:%d/queue/zoned",
+
+       if (asprintf(&sys_devno_path, "/sys/dev/block/%d:%d",
                     major(statbuf.st_rdev), minor(statbuf.st_rdev)) < 0)
                goto out;
+
+       sz = readlink(sys_devno_path, sys_path, sizeof(sys_path) - 1);
+       if (sz < 0)
+               goto out;
+       sys_path[sz] = '\0';
+
+       /*
+        * If the device is a partition device, cut the device name in the
+        * canonical sysfs path to obtain the sysfs path of the holder device.
+        *   e.g.:  /sys/devices/.../sda/sda1 -> /sys/devices/.../sda
+        */
+       if (asprintf(&part_attr_path, "/sys/dev/block/%s/partition",
+                    sys_path) < 0)
+               goto out;
+       part_str = read_file(part_attr_path);
+       if (part_str && *part_str == '1') {
+               delim = strrchr(sys_path, '/');
+               if (!delim)
+                       goto out;
+               *delim = '\0';
+       }
+
+       if (asprintf(&zoned_attr_path,
+                    "/sys/dev/block/%s/queue/zoned", sys_path) < 0)
+               goto out;
+
        model_str = read_file(zoned_attr_path);
        if (!model_str)
                goto out;
@@ -246,6 +279,9 @@ static enum blk_zoned_model get_zbd_model(const char *file_name)
 out:
        free(model_str);
        free(zoned_attr_path);
+       free(part_str);
+       free(part_attr_path);
+       free(sys_devno_path);
        return model;
 }