ircd::fs::dev: Add block device information system w/ sysfs.

include/ircd/fs/dev.h

@@ -13,6 +13,8 @@
 
 namespace ircd::fs::dev
 {
+	struct init;
+	struct blkdev;
 	using major_minor = std::pair<ulong, ulong>;
 
 	// Convert device ID's with the major(3) / minor(3) / makedev(3)
@@ -26,8 +28,33 @@ namespace ircd::fs::dev
 	// Read data for a device from sysfs; path is relative to /sys/dev/block/$id/...
 	string_view sysfs(const mutable_buffer &out, const ulong &id, const string_view &path);
 	template<class T = size_t, size_t bufmax = 32> T sysfs(const ulong &id, const string_view &path);
+
+	extern std::map<major_minor, blkdev> block;
 }
 
+struct ircd::fs::dev::blkdev
+{
+	bool is_device {false};
+	bool is_queue {false};
+	std::string type;
+	std::string vendor;
+	std::string model;
+	std::string rev;
+	size_t size {0};
+	size_t queue_depth {0};
+	size_t nr_requests {0};
+	bool rotational {false};
+
+	blkdev(const ulong &id);
+	blkdev() = default;
+};
+
+struct ircd::fs::dev::init
+{
+	init();
+	~init() noexcept;
+};
+
 /// Return a lex_cast'able (an integer) from a sysfs target.
 template<class T,
          size_t bufmax>

include/ircd/fs/fs.h

@@ -78,6 +78,7 @@ namespace ircd::fs
 /// Filesystem interface init / fini held by ircd::main().
 struct ircd::fs::init
 {
+	dev::init _dev_;
 	iou::init _iou_;
 	aio::init _aio_;
 

ircd/fs_dev.cc

@@ -10,6 +10,69 @@
 
 #include <RB_INC_SYS_SYSMACROS_H
 
+decltype(ircd::fs::dev::block)
+ircd::fs::dev::block;
+
+//
+// init
+//
+
+ircd::fs::dev::init::init()
+{
+	#ifdef __linux__
+	for(const auto &dir : fs::ls("/sys/dev/block"))
+	{
+		const auto &[major, minor]
+		{
+			split(filename(path_scratch, dir), ':')
+		};
+
+		const major_minor device_major_minor
+		{
+			lex_cast<ulong>(major), lex_cast<ulong>(minor)
+		};
+
+		const auto iit
+		{
+			block.emplace(device_major_minor, id(device_major_minor))
+		};
+
+		assert(iit.second);
+		const auto &bd(iit.first->second);
+		if(!bd.is_device || bd.type != "disk")
+			block.erase(iit.first);
+	}
+	#endif
+
+	for(const auto &[mm, bd] : block)
+	{
+		char pbuf[48];
+		log::info
+		{
+			log, "%s %u:%2u %s %s %s %s queue depth:%zu requests:%zu",
+			bd.type,
+			std::get<0>(mm),
+			std::get<1>(mm),
+			bd.vendor,
+			bd.model,
+			bd.rev,
+			pretty(pbuf, iec(bd.size)),
+			bd.queue_depth,
+			bd.nr_requests,
+		};
+	}
+
+}
+
+ircd::fs::dev::init::~init()
+noexcept
+{
+}
+
+//
+// fs::dev
+//
+
 #ifdef __linux__
 ircd::string_view
 ircd::fs::dev::sysfs(const mutable_buffer &out,
@@ -78,3 +141,99 @@ ircd::fs::dev::id(const ulong &id)
 		major(id), minor(id)
 	};
 }
+
+//
+// dev::device
+//
+
+ircd::fs::dev::blkdev::blkdev(const ulong &id)
+:is_device
+{
+	fs::is_dir(fmt::sprintf
+	{
+		path_scratch, "/sys/dev/block/%s/device",
+		sysfs_id(name_scratch, id),
+	})
+}
+,is_queue
+{
+	fs::is_dir(fmt::sprintf
+	{
+		path_scratch, "/sys/dev/block/%s/queue",
+		sysfs_id(name_scratch, id),
+	})
+}
+,type
+{
+	!is_device? std::string{}:
+	ircd::string(8, [&id]
+	(const mutable_buffer &buf)
+	{
+		char tmp[128];
+		string_view ret;
+		tokens(sysfs(tmp, id, "uevent"), '\n', [&buf, &ret]
+		(const string_view &kv)
+		{
+			const auto &[key, value]
+			{
+				split(kv, '=')
+			};
+
+			if(key == "DEVTYPE")
+				ret = strlcpy(buf, value);
+		});
+
+		return ret;
+	})
+}
+,vendor
+{
+	!is_device? std::string{}:
+	ircd::string(12, [&id]
+	(const mutable_buffer &buf)
+	{
+		return sysfs(buf, id, "device/vendor");
+	})
+}
+,model
+{
+	!is_device? std::string{}:
+	ircd::string(64, [&id]
+	(const mutable_buffer &buf)
+	{
+		return sysfs(buf, id, "device/model");
+	})
+}
+,rev
+{
+	!is_device? std::string{}:
+	ircd::string(12, [&id]
+	(const mutable_buffer &buf)
+	{
+		return sysfs(buf, id, "device/rev");
+	})
+}
+,size
+{
+	sysfs(id, "size")
+}
+,queue_depth
+{
+	is_device?
+		sysfs(id, "device/queue_depth"):
+		0UL
+}
+,nr_requests
+{
+	is_queue?
+		sysfs(id, "queue/nr_requests"):
+		0UL
+}
+,rotational
+{
+	is_queue?
+		sysfs<bool>(id, "queue/rotational"):
+		true
+}
+{
+}