Add fd.c and ds.h: functions for computing free disk space.

4 files changed, 58 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index c9e16ac..e0eeb48 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-dss_objects := dss.o cmdline.o string.o fd.o exec.o signal.o daemon.o
+dss_objects := dss.o cmdline.o string.o fd.o exec.o signal.o daemon.o df.o
 all: dss
 man: dss.1
 
diff --git a/df.c b/df.c
new file mode 100644
index 0000000..c0c42f8
--- /dev/null
+++ b/df.c
@@ -0,0 +1,35 @@
+#include <sys/statvfs.h>
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+#include <sys/types.h>
+#include <errno.h>
+
+#include "gcc-compat.h"
+#include "error.h"
+#include "string.h"
+#include "df.h"
+
+int get_disk_space(const char *path, struct disk_space *result)
+{
+	/* using floats allows to not care about integer overflows */
+	float total_blocks, available_blocks, blocksize;
+	float total_inodes, available_inodes;
+
+	struct statvfs vfs;
+	int ret = statvfs(path, &vfs);
+	if (ret < 0)
+		return -ERRNO_TO_DSS_ERROR(errno);
+
+	available_blocks = vfs.f_bavail;
+	blocksize = vfs.f_bsize;
+	total_blocks = vfs.f_blocks;
+	total_inodes = vfs.f_files;
+	available_inodes = vfs.f_ffree;
+
+	result->total_mb = total_blocks * blocksize / 1024.0 / 1024.0;
+	result->free_mb =  available_blocks * blocksize / 1024.0 / 1024.0;
+	result->percent_free = 100.0 * available_blocks / total_blocks + 0.5;
+	result->percent_free_inodes = 100.0 * available_inodes / total_inodes + 0.5;
+	return 1;
+}
diff --git a/df.h b/df.h
new file mode 100644
index 0000000..d89531f
--- /dev/null
+++ b/df.h
@@ -0,0 +1,9 @@
+struct disk_space {
+	unsigned total_mb;
+	unsigned free_mb;
+	unsigned percent_free;
+	unsigned percent_free_inodes;
+};
+
+int get_disk_space(const char *path, struct disk_space *result);
+
diff --git a/dss.c b/dss.c
index 3612d4f..1fa6d56 100644
--- a/dss.c
+++ b/dss.c
@@ -24,6 +24,7 @@
 #include "exec.h"
 #include "daemon.h"
 #include "signal.h"
+#include "df.h"
 
 
 struct gengetopt_args_info conf;
@@ -472,12 +473,24 @@ int com_run(void)
 	return 42;
 }
 
+void log_disk_space(struct disk_space *ds)
+{
+	DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
+		ds->free_mb, ds->total_mb, ds->percent_free,
+		ds->percent_free_inodes);
+}
+
 int com_prune(void)
 {
 	int ret;
 	struct snapshot_list sl;
 	pid_t pid;
+	struct disk_space ds;
 
+	ret = get_disk_space(".", &ds);
+	if (ret < 0)
+		return ret;
+	log_disk_space(&ds);
 	for (;;) {
 		get_snapshot_list(&sl);
 		ret = remove_old_snapshot(&sl, &pid);