system: add diskfree infos to ubus

This change adds the missing information about how much space is available
on the root directory and in the temp directory. I took this
implementation from the luci2 repository and adapted it for the procd
service.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

diff --git a/system.c b/system.c
index c208e3ee47434d3433aaa6ead4d3f75df803c6fc..5811d3982a583986f28c3b59783e01945e1f02f4 100644 (file)
--- a/system.c
+++ b/system.c
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 #include <sys/reboot.h>
 #include <sys/stat.h>
+#include <sys/statvfs.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <unistd.h>
@@ -312,6 +313,12 @@ static int system_board(struct ubus_context *ctx, struct ubus_object *obj,
        return UBUS_STATUS_OK;
 }
 
+static unsigned long
+kscale(unsigned long b, unsigned long bs)
+{
+       return (b * (unsigned long long) bs + 1024/2) / 1024;
+}
+
 static int system_info(struct ubus_context *ctx, struct ubus_object *obj,
                 struct ubus_request_data *req, const char *method,
                 struct blob_attr *msg)
@@ -325,6 +332,12 @@ static int system_info(struct ubus_context *ctx, struct ubus_object *obj,
        char *key, *val;
        unsigned long long available, cached;
        FILE *f;
+       int i;
+       struct statvfs s;
+       const char *fslist[] = {
+               "/",    "root",
+               "/tmp", "tmp",
+       };
 
        if (sysinfo(&info))
                return UBUS_STATUS_UNKNOWN_ERROR;
@@ -384,6 +397,23 @@ static int system_info(struct ubus_context *ctx, struct ubus_object *obj,
        blobmsg_add_u64(&b, "cached", cached);
        blobmsg_close_table(&b, c);
 
+       for (i = 0; i < sizeof(fslist) / sizeof(fslist[0]); i += 2) {
+               if (statvfs(fslist[i], &s))
+                       continue;
+
+               c = blobmsg_open_table(&b, fslist[i+1]);
+
+               if (!s.f_frsize)
+                       s.f_frsize = s.f_bsize;
+
+               blobmsg_add_u64(&b, "total", kscale(s.f_blocks, s.f_frsize));
+               blobmsg_add_u64(&b, "free",  kscale(s.f_bfree, s.f_frsize));
+               blobmsg_add_u64(&b, "used", kscale(s.f_blocks - s.f_bfree, s.f_frsize));
+               blobmsg_add_u64(&b, "avail", kscale(s.f_bavail, s.f_frsize));
+
+               blobmsg_close_table(&b, c);
+       }
+
        c = blobmsg_open_table(&b, "swap");
        blobmsg_add_u64(&b, "total",
                        (uint64_t)info.mem_unit * (uint64_t)info.totalswap);