[PATCH 4/5] lnvm: introduce chunk-log command for chunk info

[minwoo.im.dev@gmail.com (Minwoo Im)]

To retrieve the chunk information from the nvme namespae for the given
OCSSD, we can just do like:
	nvme lnvm chunk-log /dev/nvme0n1 --output-format=normal

This will calculate the data length from the geometry data structure
which might be retrieved by a Geometry command(Identity for 1.2 spec.).
Then it will request get log page API for 1.3 NVMe spec to get the
entries which indicate chunk information.

Cc: Keith Busch <kbusch at kernel.org>
Cc: Matias Bjorling <mb at lightnvm.io>
Signed-off-by: Minwoo Im <minwoo.im.dev at gmail.com>
---
 nvme-lightnvm.c          | 37 ++++++++++++++++++
 nvme-lightnvm.h          |  1 +
 plugins/lnvm/lnvm-nvme.c | 84 ++++++++++++++++++++++++++++++++++++++++
 plugins/lnvm/lnvm-nvme.h |  1 +
 4 files changed, 123 insertions(+)

diff --git a/nvme-lightnvm.c b/nvme-lightnvm.c
index 2e665bf..8fa8f3f 100644
--- a/nvme-lightnvm.c
+++ b/nvme-lightnvm.c
@@ -465,6 +465,43 @@ int lnvm_do_id_ns(int fd, int nsid, unsigned int flags)
 	return err;
 }
 
+static void show_lnvm_chunk_log(struct nvme_nvm_chunk_desc *chunk_log,
+				__u32 data_len)
+{
+	int nr_entry = data_len / sizeof(struct nvme_nvm_chunk_desc);
+	int idx;
+
+	for (idx = 0; idx < nr_entry; idx++) {
+		struct nvme_nvm_chunk_desc *desc = &chunk_log[idx];
+
+		printf(" [%5d] { ", idx);
+		printf("cs: %#x", desc->cs);
+		printf(", ct: %#x", desc->ct);
+		printf(", wli: %d", desc->wli);
+		printf(", slba: 0x%016"PRIx64, le64_to_cpu(desc->slba));
+		printf(", cnlb: 0x%016"PRIx64, le64_to_cpu(desc->cnlb));
+		printf(", wp: 0x%016"PRIx64" }\n", le64_to_cpu(desc->wp));
+	}
+}
+
+int lnvm_do_chunk_log(int fd, __u32 nsid, __u32 data_len, void *data,
+			unsigned int flags)
+{
+	int err;
+
+	err = nvme_get_log13(fd, nsid, NVM_LID_CHUNK_INFO, 0, 0, 0,
+			false, data_len, data);
+	if (!err) {
+		if (flags & RAW)
+			d_raw(data, data_len);
+		else
+			show_lnvm_chunk_log(data, data_len);
+	} else if (err > 0)
+		fprintf(stderr, "NVMe Status:%s(%x) NSID:%d\n",
+			nvme_status_to_string(err), err, nsid);
+	return err;
+}
+
 static void show_lnvm_bbtbl(struct nvme_nvm_bb_tbl *tbl)
 {
 	printf("verid    : %#x\n", (uint16_t)le16_to_cpu(tbl->verid));
diff --git a/nvme-lightnvm.h b/nvme-lightnvm.h
index 7a8ef7d..19660b7 100644
--- a/nvme-lightnvm.h
+++ b/nvme-lightnvm.h
@@ -322,6 +322,7 @@ int lnvm_do_create_tgt(char *, char *, char *, int, int, int, int);
 int lnvm_do_remove_tgt(char *);
 int lnvm_do_factory_init(char *, int, int, int);
 int lnvm_do_id_ns(int, int, unsigned int);
+int lnvm_do_chunk_log(int, __u32, __u32, void *, unsigned int);
 int lnvm_do_get_bbtbl(int, int, int, int, unsigned int);
 int lnvm_do_set_bbtbl(int, int, int, int, int, int, __u8);
 
diff --git a/plugins/lnvm/lnvm-nvme.c b/plugins/lnvm/lnvm-nvme.c
index 754931a..6f2724a 100644
--- a/plugins/lnvm/lnvm-nvme.c
+++ b/plugins/lnvm/lnvm-nvme.c
@@ -1,5 +1,7 @@
 #include <stdio.h>
 #include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
 
 #include "nvme.h"
 #include "nvme-print.h"
@@ -127,6 +129,88 @@ static int lnvm_id_ns(int argc, char **argv, struct command *cmd, struct plugin
 	return lnvm_do_id_ns(fd, cfg.namespace_id, flags);
 }
 
+static int lnvm_chunk_log(int argc, char **argv, struct command *cmd, struct plugin *plugin)
+{
+	const char *desc = "Retrieve the chunk information log for the "\
+		"specified given LightNVM device, returns in either "\
+		"human-readable or binary format.\n"\
+		"This will request Geometry first to get the "\
+		"num_grp,num_pu,num_chk first to figure out the total size "\
+		"of the log pages."\
+		;
+	const char *output_format = "Output format: normal|binary";
+	const char *human_readable = "Print normal in readable format";
+	int err, fmt, fd;
+	struct nvme_nvm_id20 geo;
+	struct nvme_nvm_chunk_desc *chunk_log;
+	__u32 nsid;
+	__u32 data_len;
+	unsigned int flags = 0;
+
+	struct config {
+		char *output_format;
+		int human_readable;
+	};
+
+	struct config cfg = {
+		.output_format = "normal",
+	};
+
+	const struct argconfig_commandline_options command_line_options[] = {
+		{"output-format", 'o', "FMT", CFG_STRING, &cfg.output_format, required_argument, output_format},
+		{"human-readable",'H', "",    CFG_NONE,   &cfg.human_readable,no_argument,       human_readable},
+		{NULL}
+	};
+
+	fd = parse_and_open(argc, argv, desc, command_line_options, &cfg,
+				sizeof(cfg));
+	if (fd < 0) {
+		err = fd;
+		goto ret;
+	}
+
+	fmt = validate_output_format(cfg.output_format);
+	if (fmt < 0) {
+		err = fmt;
+		goto close;
+	}
+
+	if (fmt == BINARY)
+		flags |= RAW;
+	else if (cfg.human_readable)
+		flags |= HUMAN;
+
+	nsid = nvme_get_nsid(fd);
+
+	/*
+	 * It needs to figure out how many bytes will be requested by this
+	 * subcommand by the (num_grp * num_pu * num_chk) from the Geometry.
+	 */
+	err = lnvm_get_identity(fd, nsid, (struct nvme_nvm_id *) &geo);
+	if (err)
+		goto close;
+
+	data_len = (geo.num_grp * geo.num_pu * geo.num_chk) *
+			sizeof(struct nvme_nvm_chunk_desc);
+	chunk_log = malloc(data_len);
+	if (!chunk_log) {
+		fprintf(stderr, "cound not alloc for chunk log %dbytes\n",
+				data_len);
+		err = -ENOMEM;
+		goto close;
+	}
+
+	err = lnvm_do_chunk_log(fd, nsid, data_len, chunk_log, flags);
+	if (err)
+		fprintf(stderr, "get log page for chunk information failed\n");
+
+	free(chunk_log);
+close:
+	close(fd);
+ret:
+	return err;
+}
+
 static int lnvm_create_tgt(int argc, char **argv, struct command *cmd, struct plugin *plugin)
 {
 	const char *desc = "Instantiate a target on top of a LightNVM enabled device.";
diff --git a/plugins/lnvm/lnvm-nvme.h b/plugins/lnvm/lnvm-nvme.h
index 3d5cbc5..f091f7b 100644
--- a/plugins/lnvm/lnvm-nvme.h
+++ b/plugins/lnvm/lnvm-nvme.h
@@ -12,6 +12,7 @@ PLUGIN(NAME("lnvm", "LightNVM specific extensions"),
 		ENTRY("list", "List available LightNVM devices", lnvm_list)
 		ENTRY("info", "List general information and available target engines", lnvm_info)
 		ENTRY("id-ns", "List geometry for LightNVM device", lnvm_id_ns)
+		ENTRY("chunk-log", "Chunk information by Get Log Page", lnvm_chunk_log)
 		ENTRY("init", "Initialize media manager on LightNVM device", lnvm_init)
 		ENTRY("create", "Create target on top of a LightNVM device", lnvm_create_tgt)
 		ENTRY("remove", "Remove target from device", lnvm_remove_tgt)
-- 
2.17.1