bcachefs fs top

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

c_src/bcachefs.c

@@ -52,6 +52,7 @@ void bcachefs_usage(void)
 #endif
 	     "Commands for managing a running filesystem:\n"
 	     "  fs usage                 Show disk usage\n"
+	     "  fs top                   Show runtime performance information\n"
 	     "\n"
 	     "Commands for managing devices within a running filesystem:\n"
 	     "  device add               Add a new device to an existing filesystem\n"
@@ -119,6 +120,8 @@ int fs_cmds(int argc, char *argv[])
 	}
 	if (!strcmp(cmd, "usage"))
 		return cmd_fs_usage(argc, argv);
+	if (!strcmp(cmd, "top"))
+		return cmd_fs_top(argc, argv);
 
 	return 0;
 }

c_src/cmd_top.c

@@ -0,0 +1,98 @@
+#include <dirent.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+
+#include "cmds.h"
+#include "libbcachefs.h"
+#include "libbcachefs/sb-counters.h"
+
+static const u8 counters_to_stable_map[] = {
+#define x(n, id, ...)	[BCH_COUNTER_##n] = BCH_COUNTER_STABLE_##n,
+	BCH_PERSISTENT_COUNTERS()
+#undef x
+};
+
+static struct bch_ioctl_query_counters *read_counters(struct bchfs_handle fs)
+{
+	struct bch_ioctl_query_counters *ret =
+		kzalloc(sizeof(*ret) + sizeof(ret->d[0]) * BCH_COUNTER_NR, GFP_KERNEL);
+
+	ret->nr = BCH_COUNTER_NR;
+
+	xioctl(fs.ioctl_fd, BCH_IOCTL_QUERY_COUNTERS, ret);
+	return ret;
+}
+
+static void fs_top(const char *path, bool human_readable)
+{
+	struct bchfs_handle fs = bcache_fs_open(path);
+
+	struct bch_ioctl_query_counters *curr, *prev = NULL;
+
+	curr = read_counters(fs);
+
+	while (true) {
+		sleep(1);
+		kfree(prev);
+		prev = curr;
+		curr = read_counters(fs);
+
+		printf("\033[2J");
+		printf("\033[H");
+
+		for (unsigned i = 0; i < BCH_COUNTER_NR; i++) {
+			unsigned stable = counters_to_stable_map[i];
+			u64 v = stable < curr->nr
+				?  curr->d[stable] - prev->d[stable]
+				: 0;
+			printf("%-48s %llu\n",
+			       bch2_counter_names[i],
+			       v);
+		}
+	}
+
+	bcache_fs_close(fs);
+}
+
+static void fs_top_usage(void)
+{
+	puts("bcachefs fs top - display runtime perfomance info\n"
+	     "Usage: bcachefs fs top [OPTION]... <mountpoint>\n"
+	     "\n"
+	     "Options:\n"
+	     "  -h, --human-readable              Human readable units\n"
+	     "  -H, --help                        Display this help and exit\n"
+	     "Report bugs to <linux-bcachefs@vger.kernel.org>");
+}
+
+int cmd_fs_top(int argc, char *argv[])
+{
+	static const struct option longopts[] = {
+		{ "help",		no_argument,		NULL, 'H' },
+		{ "human-readable",     no_argument,            NULL, 'h' },
+		{ NULL }
+	};
+	bool human_readable = false;
+	int opt;
+
+	while ((opt = getopt_long(argc, argv, "Hh",
+				  longopts, NULL)) != -1)
+		switch (opt) {
+		case 'h':
+			human_readable = true;
+			break;
+		case 'H':
+			fs_top_usage();
+			exit(EXIT_SUCCESS);
+		default:
+			fs_top_usage();
+			exit(EXIT_FAILURE);
+		}
+	args_shift(optind);
+
+	fs_top(arg_pop() ?: ".", human_readable) ;
+	return 0;
+}

c_src/cmds.h

@@ -15,6 +15,7 @@ int cmd_reset_counters(int argc, char *argv[]);
 int cmd_set_option(int argc, char *argv[]);
 
 int cmd_fs_usage(int argc, char *argv[]);
+int cmd_fs_top(int argc, char *argv[]);
 
 int device_usage(void);
 int cmd_device_add(int argc, char *argv[]);