WIP: Add info command

This just reads the sysfs nodes and presents the information in a
convenient way.

Makefile

@@ -81,6 +81,7 @@ LIB_SRCS := \
 	open.c \
 	resize.c \
 	stats.c \
+	info.c \
 	tune.c \
 	util.c
 BIN_SRCS := \

cbd/cbd.c

@@ -489,6 +489,31 @@ do_stats(int argc, char** argv)
     return 0;
 }
 
+static int
+do_info(int argc, char** argv)
+{
+    const char* name;
+    struct cbd_info info;
+
+    if (argc != 2) {
+        usage();
+    }
+    name = argv[1];
+
+    cbd_info(name, &info);
+    printf("Info:\n");
+    printf("pblk used: %u%% (%lu of %lu)\n",
+            (unsigned int)((100 * info.pblk_used) / info.pblk_total),
+            (unsigned long)info.pblk_used,
+            (unsigned long)info.pblk_total);
+    printf("lblk used: %u%% (%lu of %lu)\n",
+            (unsigned int)((100 * info.lblk_used) / info.lblk_total),
+            (unsigned long)info.lblk_used,
+            (unsigned long)info.lblk_total);
+
+    return 0;
+}
+
 static int
 do_tune(int argc, char** argv)
 {
@@ -563,6 +588,7 @@ static struct cmd_dispatch dispatch[] =
     { "check",  do_check },
     { "resize", do_resize },
     { "stats",  do_stats },
+    { "info",   do_info },
     { "tune",   do_tune },
 };
 

include/libcbd.h

@@ -71,6 +71,22 @@ typedef enum {
     t_none
 } tristate_t;
 
+struct cbd_info {
+    u64     lbatpblk_r;
+    u64     lbatpblk_w;
+    u64     lbd_r;
+    u64     lbd_w;
+    u64     lblk_size;
+    u64     lblk_total;
+    u64     lblk_used;
+    u64     pbat_r;
+    u64     pbat_w;
+    u64     pblk_total;
+    u64     pblk_used;
+    u64     zone_init;
+    u64     zone_total;
+};
+
 int    cbd_format(const char* dev,
         uint16_t flags,
         enum cbd_alg alg, uint level,
@@ -83,6 +99,8 @@ int    cbd_open(const char* dev,
 int    cbd_close(const char* name);
 int    cbd_stats(const char* dev,
         struct cbd_stats* stats);
+int    cbd_info(const char* dev,
+        struct cbd_info* info);
 int    cbd_check(const char* dev,
         bool force,
         tristate_t auto_response,

libcbd/info.c

@@ -0,0 +1,46 @@
+#include <libcbd.h>
+
+#include <cbdutil.h>
+
+static u64
+get_sysfs_value(const char* dirname, const char* filename)
+{
+    char pathname[PATH_MAX];
+    int fd;
+    char buf[80];
+
+    sprintf(pathname, "%s/%s", dirname, filename);
+    fd = open(pathname, O_RDONLY);
+    if (fd < 0) {
+        error("Cannot open device\n");
+    }
+    if (read(fd, buf, sizeof(buf)) < 1) {
+        error("Cannot read device\n");
+    }
+    close(fd);
+    return (u64)strtoul(buf, NULL, 10);
+}
+
+int
+cbd_info(const char* dev, struct cbd_info* info)
+{
+    char dirname[PATH_MAX];
+
+    sprintf(dirname, "/sys/fs/compress/%s", dev);
+
+    info->lbatpblk_r = get_sysfs_value(dirname, "lbatpblk_r");
+    info->lbatpblk_w = get_sysfs_value(dirname, "lbatpblk_w");
+    info->lbd_r = get_sysfs_value(dirname, "lbd_r");
+    info->lbd_w = get_sysfs_value(dirname, "lbd_w");
+    info->lblk_size = get_sysfs_value(dirname, "lblk_size");
+    info->lblk_total = get_sysfs_value(dirname, "lblk_total");
+    info->lblk_used = get_sysfs_value(dirname, "lblk_used");
+    info->pbat_r = get_sysfs_value(dirname, "pbat_r");
+    info->pbat_w = get_sysfs_value(dirname, "pbat_w");
+    info->pblk_total = get_sysfs_value(dirname, "pblk_total");
+    info->pblk_used = get_sysfs_value(dirname, "pblk_used");
+    info->zone_init = get_sysfs_value(dirname, "zone_init");
+    info->zone_total = get_sysfs_value(dirname, "zone_total");
+
+    return 0;
+}