iovisor · dkruces · Oct 29, 2024
@@ -35,7 +35,8 @@ RUN dnf -y install \
 	python3-devel \
 	libstdc++ \
 	libstdc++-devel \
-	systemtap-sdt-devel
+	systemtap-sdt-devel \
+	json-c-devel
 
 RUN dnf -y install \
 	python3 \

@@ -133,7 +133,7 @@ $(call allow-override,CC,$(CROSS_COMPILE)cc)
 $(call allow-override,LD,$(CROSS_COMPILE)ld)
 
 .PHONY: all
-all: $(APPS) $(APP_ALIASES)
+all: $(APPS) $(APP_ALIASES) blkalgn
 
 ifeq ($(V),1)
 Q =
@@ -161,7 +161,7 @@ endif
 .PHONY: clean
 clean:
 	$(call msg,CLEAN)
-	$(Q)rm -rf $(OUTPUT) $(APPS) $(APP_ALIASES)
+	$(Q)rm -rf $(OUTPUT) $(APPS) $(APP_ALIASES) blkalgn
 
 $(LIBBLAZESYM_SRC)::
 	$(Q)cd blazesym && cargo build --release --features=cheader
@@ -186,12 +186,18 @@ $(APPS): %: $(OUTPUT)/%.o $(COMMON_OBJ) $(LIBBPF_OBJ) | $(OUTPUT)
 	$(call msg,BINARY,$@)
 	$(Q)$(CC) $(CFLAGS) $^ $(LDFLAGS) -lelf -lz -o $@
 
+blkalgn: %: $(OUTPUT)/%.o $(COMMON_OBJ) $(LIBBPF_OBJ) | $(OUTPUT)
+	$(call msg,BINARY,$@)
+	$(Q)$(CC) $(CFLAGS) $^ $(LDFLAGS) -lelf -lz -ljson-c -lm -o $@
+
 ifeq ($(USE_BLAZESYM),1)
 $(patsubst %,$(OUTPUT)/%.o,$(BZ_APPS)): $(OUTPUT)/blazesym.h
 endif
 
 $(patsubst %,$(OUTPUT)/%.o,$(APPS)): %.o: %.skel.h
 
+$(patsubst %,$(OUTPUT)/%.o,blkalgn): %.o: %.skel.h
+
 $(OUTPUT)/%.o: %.c $(wildcard %.h) $(LIBBPF_OBJ) | $(OUTPUT)
 	$(call msg,CC,$@)
 	$(Q)$(CC) $(CFLAGS) $(INCLUDES) -c $(filter %.c,$^) -o $@
@@ -200,6 +206,10 @@ $(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(OUTPUT) $(BPFTOOL)
 	$(call msg,GEN-SKEL,$@)
 	$(Q)$(BPFTOOL) gen skeleton $< > $@
 
+$(OUTPUT)/blkalgn.skel.h: $(OUTPUT)/blkalgn.bpf.o | $(OUTPUT) $(BPFTOOL)
+	$(call msg,GEN-SKEL,$@)
+	$(Q)$(BPFTOOL) gen skeleton $< > $@
+
 $(OUTPUT)/softirqs.bpf.o: BPFCFLAGS = $(BPFCFLAGS_softirqs)
 
 $(OUTPUT)/%.bpf.o: %.bpf.c $(LIBBPF_OBJ) $(wildcard %.h) $(ARCH)/vmlinux.h | $(OUTPUT)
@@ -238,11 +248,13 @@ $(SIGSNOOP_ALIAS): sigsnoop
 	$(call msg,SYMLINK,$@)
 	$(Q)ln -f -s $(APP_PREFIX)$^ $@
 
-install: $(APPS) $(APP_ALIASES)
+install: $(APPS) $(APP_ALIASES) install-blkalgn
 	$(call msg, INSTALL libbpf-tools)
 	$(Q)$(INSTALL) -m 0755 -d $(DESTDIR)$(bindir)
 	$(Q)$(foreach app,$(APPS),$(INSTALL) $(app) $(DESTDIR)$(bindir)/$(APP_PREFIX)$(app);)
-	$(Q)$(foreach alias,$(APP_ALIASES),cp -a $(alias) $(DESTDIR)$(bindir)/$(APP_PREFIX)$(alias);)
+
+install-blkalgn: blkalgn
+	$(Q)$(INSTALL) blkalgn $(DESTDIR)$(bindir)/$(APP_PREFIX)blkalgn
 
 .PHONY: force
 force:

@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Samsung */
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include "blkalgn.h"
+#include "bits.bpf.h"
+#include "core_fixes.bpf.h"
+
+const volatile bool filter_dev = false;
+const volatile __u32 targ_dev = 0;
+const volatile bool filter_ops = false;
+const volatile __u32 targ_ops = 0;
+const volatile bool filter_len = false;
+const volatile __u32 targ_len = 0;
+const volatile bool filter_comm = false;
+const volatile char targ_comm[TASK_COMM_LEN] = {};
+const volatile bool capture_stack = false;
+
+extern __u32 LINUX_KERNEL_VERSION __kconfig;
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
+
+struct {
+	__uint(type, BPF_MAP_TYPE_RINGBUF);
+	__uint(max_entries, 2097152);
+} rb SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 10240);
+	__type(key, struct hkey);
+	__type(value, struct hval);
+} halgn_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 10240);
+	__type(key, struct hkey);
+	__type(value, struct hval);
+} hgran_map SEC(".maps");
+
+static __always_inline bool comm_allowed(const char *comm)
+{
+	int i;
+
+	for (i = 0; i < TASK_COMM_LEN && targ_comm[i] != '\0'; i++) {
+		if (comm[i] != targ_comm[i])
+			return false;
+	}
+	return true;
+}
+
+static int __always_inline trace_rq_issue(void *ctx, struct request *rq)
+{
+	struct event *e;
+	u32 dev;
+	char comm[TASK_COMM_LEN];
+
+	struct gendisk *disk = get_disk(rq);
+
+	dev = disk ? MKDEV(BPF_CORE_READ(disk, major),
+			   BPF_CORE_READ(disk, first_minor)) :
+		     0;
+
+	if (filter_dev && targ_dev != dev)
+		return 0;
+
+	if (filter_ops && targ_ops != (rq->cmd_flags & 0xff))
+		return 0;
+
+	if (filter_len && targ_len != (rq->__data_len))
+		return 0;
+
+	if (filter_comm) {
+		bpf_get_current_comm(&comm, sizeof(comm));
+		if (!comm_allowed(comm))
+			return 0;
+	}
+
+	e = bpf_ringbuf_reserve(&rb, sizeof(*e), 0);
+	if (!e)
+		return 0;
+
+	bpf_get_current_comm(&e->comm, sizeof(e->comm));
+	e->pid = bpf_get_current_pid_tgid();
+	bpf_probe_read_kernel(&e->disk, sizeof(e->disk),
+			      rq->q->disk->disk_name);
+
+	if (capture_stack) {
+		e->kstack_sz =
+			bpf_get_stack(ctx, e->kstack, sizeof(e->kstack), 0);
+		e->ustack_sz = bpf_get_stack(ctx, e->ustack, sizeof(e->ustack),
+					     BPF_F_USER_STACK);
+	}
+
+	e->flags = rq->cmd_flags;
+	e->lbs = rq->q->limits.logical_block_size;
+	e->len = rq->__data_len;
+	e->sector = rq->__sector;
+
+	bpf_ringbuf_submit(e, 0);
+
+	return 0;
+}
+
+SEC("tp_btf/block_rq_issue")
+int BPF_PROG(block_rq_issue)
+{
+	/*
+	 * Commit a54895fa (v5.11-rc1) changed tracepoint argument list
+	 * from TP_PROTO(struct request_queue *q, struct request *rq)
+	 * to TP_PROTO(struct request *rq)
+	 */
+	if (LINUX_KERNEL_VERSION >= KERNEL_VERSION(5, 11, 0))
+		return trace_rq_issue(ctx, (void *)ctx[0]);
+	else
+		return trace_rq_issue(ctx, (void *)ctx[1]);
+}