From 5e7543d35596fabd9e5b02b58f8910bf572ca2fa Mon Sep 17 00:00:00 2001

From: Jerome Marchand <jmarchan@redhat.com>

Date: Thu, 7 Oct 2021 17:31:53 +0200

Subject: [PATCH] C9S: Fix mdflush

Since kernel commit 309dca309fc ("block: store a block_device pointer

in struct bio") struct bio points again to a block_device and not to a

gendisk directly. However mdflush is looking at the presence or not of

the bio_dev macro to check whether to get the gendisk directly from

the bio or not, which doesn't work anymore since the bio_dev macro

still exists. Since we don't have to deal other ekrnel kernel version

but our own, just use the definition that we use in our kernels.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>

---

 tools/mdflush.py | 11 -----------

 1 file changed, 11 deletions(-)

diff --git a/tools/mdflush.py b/tools/mdflush.py

index 8a23520b..3581d1bf 100755

--- a/tools/mdflush.py

+++ b/tools/mdflush.py

@@ -35,18 +35,7 @@ int kprobe__md_flush_request(struct pt_regs *ctx, void *mddev, struct bio *bio)

     u32 pid = bpf_get_current_pid_tgid() >> 32;

     data.pid = pid;

     bpf_get_current_comm(&data.comm, sizeof(data.comm));

-/*

- * The following deals with a kernel version change (in mainline 4.14, although

- * it may be backported to earlier kernels) with how the disk name is accessed.

- * We handle both pre- and post-change versions here. Please avoid kernel

- * version tests like this as much as possible: they inflate the code, test,

- * and maintenance burden.

- */

-#ifdef bio_dev

-    struct gendisk *bi_disk = bio->bi_disk;

-#else

     struct gendisk *bi_disk = bio->bi_bdev->bd_disk;

-#endif

     bpf_probe_read_kernel(&data.disk, sizeof(data.disk), bi_disk->disk_name);

     events.perf_submit(ctx, &data, sizeof(data));

     return 0;

-- 

2.35.1