From 879792d2d47c1308e884fb59d92fe535f7bb8d71 Mon Sep 17 00:00:00 2001

From: Tejun Heo <tj@kernel.org>

Date: Thu, 10 Mar 2022 08:37:21 -1000

Subject: [PATCH 1/2] biolatency, biolatpcts, biosnoop, biotop: Build fix for

 v5.17+

During 5.17 dev cycle, the kernel dropped request->rq_disk. It can now be

accessed through request->q->disk. Fix the python ones in tools/. There are

more usages in other places which need to be fixed too.

Signed-off-by: Tejun Heo <tj@kernel.org>

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

---

 tools/biolatency.py |  8 ++++++--

 tools/biolatpcts.py | 11 ++++++++---

 tools/biosnoop.py   |  6 +++++-

 tools/biotop.py     |  9 +++++++--

 4 files changed, 26 insertions(+), 8 deletions(-)

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

index 427cee47..10c852ac 100755

--- a/tools/biolatency.py

+++ b/tools/biolatency.py

@@ -128,12 +128,16 @@ storage_str = ""

 store_str = ""

 if args.disks:

     storage_str += "BPF_HISTOGRAM(dist, disk_key_t);"

-    store_str += """

+    disks_str = """

     disk_key_t key = {.slot = bpf_log2l(delta)};

-    void *__tmp = (void *)req->rq_disk->disk_name;

+    void *__tmp = (void *)req->__RQ_DISK__->disk_name;

     bpf_probe_read(&key.disk, sizeof(key.disk), __tmp);

     dist.atomic_increment(key);

     """

+    if BPF.kernel_struct_has_field(b'request', b'rq_disk'):

+        store_str += disks_str.replace('__RQ_DISK__', 'rq_disk')

+    else:

+        store_str += disks_str.replace('__RQ_DISK__', 'q->disk')

 elif args.flags:

     storage_str += "BPF_HISTOGRAM(dist, flag_key_t);"

     store_str += """

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

index 0f334419..ea8b1ce6 100755

--- a/tools/biolatpcts.py

+++ b/tools/biolatpcts.py

@@ -72,9 +72,9 @@ void kprobe_blk_account_io_done(struct pt_regs *ctx, struct request *rq, u64 now

         if (!rq->__START_TIME_FIELD__)

                 return;

-        if (!rq->rq_disk ||

-            rq->rq_disk->major != __MAJOR__ ||

-            rq->rq_disk->first_minor != __MINOR__)

+        if (!rq->__RQ_DISK__ ||

+            rq->__RQ_DISK__->major != __MAJOR__ ||

+            rq->__RQ_DISK__->first_minor != __MINOR__)

                 return;

         cmd_flags = rq->cmd_flags;

@@ -142,6 +142,11 @@ bpf_source = bpf_source.replace('__START_TIME_FIELD__', start_time_field)

 bpf_source = bpf_source.replace('__MAJOR__', str(major))

 bpf_source = bpf_source.replace('__MINOR__', str(minor))

+if BPF.kernel_struct_has_field(b'request', b'rq_disk'):

+    bpf_source = bpf_source.replace('__RQ_DISK__', 'rq_disk')

+else:

+    bpf_source = bpf_source.replace('__RQ_DISK__', 'q->disk')

+

 bpf = BPF(text=bpf_source)

 if BPF.get_kprobe_functions(b'__blk_account_io_done'):

     bpf.attach_kprobe(event="__blk_account_io_done", fn_name="kprobe_blk_account_io_done")

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

index ae38e384..a2b636aa 100755

--- a/tools/biosnoop.py

+++ b/tools/biosnoop.py

@@ -125,7 +125,7 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

         data.pid = valp->pid;

         data.sector = req->__sector;

         bpf_probe_read_kernel(&data.name, sizeof(data.name), valp->name);

-        struct gendisk *rq_disk = req->rq_disk;

+        struct gendisk *rq_disk = req->__RQ_DISK__;

         bpf_probe_read_kernel(&data.disk_name, sizeof(data.disk_name),

                        rq_disk->disk_name);

     }

@@ -156,6 +156,10 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

     bpf_text = bpf_text.replace('##QUEUE##', '1')

 else:

     bpf_text = bpf_text.replace('##QUEUE##', '0')

+if BPF.kernel_struct_has_field(b'request', b'rq_disk'):

+    bpf_text = bpf_text.replace('__RQ_DISK__', 'rq_disk')

+else:

+    bpf_text = bpf_text.replace('__RQ_DISK__', 'q->disk')

 if debug or args.ebpf:

     print(bpf_text)

     if args.ebpf:

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

index b3e3ea00..882835f6 100755

--- a/tools/biotop.py

+++ b/tools/biotop.py

@@ -129,8 +129,8 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

     // setup info_t key

     struct info_t info = {};

-    info.major = req->rq_disk->major;

-    info.minor = req->rq_disk->first_minor;

+    info.major = req->__RQ_DISK__->major;

+    info.minor = req->__RQ_DISK__->first_minor;

 /*

  * The following deals with a kernel version change (in mainline 4.7, although

  * it may be backported to earlier kernels) with how block request write flags

@@ -174,6 +174,11 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

     print(bpf_text)

     exit()

+if BPF.kernel_struct_has_field(b'request', b'rq_disk'):

+    bpf_text = bpf_text.replace('__RQ_DISK__', 'rq_disk')

+else:

+    bpf_text = bpf_text.replace('__RQ_DISK__', 'q->disk')

+

 b = BPF(text=bpf_text)

 if BPF.get_kprobe_functions(b'__blk_account_io_start'):

     b.attach_kprobe(event="__blk_account_io_start", fn_name="trace_pid_start")

-- 

2.35.1