From 84b57000a176f676e2b70b29127455524e578f01 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Wed, 11 Oct 2017 16:00:00 +0200
Subject: [SERVER] rpc: Support querying storage size + available space

---
 src/server/fileutil.c | 14 ++++++++++----
 src/server/fileutil.h |  2 +-
 src/server/image.c    |  6 +++---
 src/server/rpc.c      | 14 +++++++++++++-
 4 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/src/server/fileutil.c b/src/server/fileutil.c
index d68649e..d41dc85 100644
--- a/src/server/fileutil.c
+++ b/src/server/fileutil.c
@@ -66,13 +66,19 @@ bool file_alloc(int fd, uint64_t offset, uint64_t size)
 	return false;
 }
 
-int64_t file_freeDiskSpace(const char * const path)
+bool file_freeDiskSpace(const char * const path, uint64_t *total, uint64_t *avail)
 {
 	struct statvfs fiData;
-	if ( (statvfs( path, &fiData )) < 0 ) {
-		return -1;
+	if ( statvfs( path, &fiData ) < 0 ) {
+		return false;
 	}
-	return ((int64_t)fiData.f_bavail * (int64_t)fiData.f_bsize);
+	if ( avail != NULL ) {
+		*avail = ((uint64_t)fiData.f_bavail * (uint64_t)fiData.f_frsize);
+	}
+	if ( total != NULL ) {
+		*total = ((uint64_t)fiData.f_blocks * (uint64_t)fiData.f_frsize);
+	}
+	return true;
 }
 
 time_t file_lastModification(const char * const file)
diff --git a/src/server/fileutil.h b/src/server/fileutil.h
index 36ee432..a4458a3 100644
--- a/src/server/fileutil.h
+++ b/src/server/fileutil.h
@@ -9,7 +9,7 @@ bool file_isReadable(char *file);
 bool file_isWritable(char *file);
 bool mkdir_p(const char* path);
 bool file_alloc(int fd, uint64_t offset, uint64_t size);
-int64_t file_freeDiskSpace(const char * const path);
+bool file_freeDiskSpace(const char * const path, uint64_t *total, uint64_t *avail);
 time_t file_lastModification(const char * const file);
 int file_loadLineBased(const char * const file, int minFields, int maxFields, void (*cb)(int argc, char **argv, void *data), void *data);
 
diff --git a/src/server/image.c b/src/server/image.c
index 1504dae..36e0f0c 100644
--- a/src/server/image.c
+++ b/src/server/image.c
@@ -1612,13 +1612,13 @@ static bool image_calcBlockCrc32(const int fd, const int block, const uint64_t r
 static bool image_ensureDiskSpace(uint64_t size)
 {
 	for ( int maxtries = 0; maxtries < 20; ++maxtries ) {
-		const int64_t available = file_freeDiskSpace( _basePath );
-		if ( available == -1 ) {
+		uint64_t available;
+		if ( !file_freeDiskSpace( _basePath, NULL, &available ) ) {
 			const int e = errno;
 			logadd( LOG_WARNING, "Could not get free disk space (errno %d), will assume there is enough space left... ;-)\n", e );
 			return true;
 		}
-		if ( (uint64_t)available > size ) return true;
+		if ( available > size ) return true;
 		if ( dnbd3_serverUptime() < 10 * 3600 ) {
 			logadd( LOG_INFO, "Only %dMiB free, %dMiB requested, but server uptime < 10 hours...", (int)(available / (1024ll * 1024ll)),
 					(int)(size / (1024 * 1024)) );
diff --git a/src/server/rpc.c b/src/server/rpc.c
index fef7f85..7f57b0a 100644
--- a/src/server/rpc.c
+++ b/src/server/rpc.c
@@ -105,13 +105,19 @@ void rpc_sendStatsJson(int sock, dnbd3_host_t* host, const void* data, const int
 static bool handleStatus(int sock, const char *request, int permissions)
 {
 	bool ok;
-	bool stats = false, images = false, clients = false;
+	bool stats = false, images = false, clients = false, space = false;
 	if ( strstr( request, "stats" ) != NULL ) {
 		if ( !(permissions & ACL_STATS) ) {
 			return sendReply( sock, "403 Forbidden", "text/plain", "No permission to access statistics", -1, HTTP_KEEPALIVE );
 		}
 		stats = true;
 	}
+	if ( strstr( request, "space" ) != NULL ) {
+		if ( !(permissions & ACL_STATS) ) {
+			return sendReply( sock, "403 Forbidden", "text/plain", "No permission to access statistics", -1, HTTP_KEEPALIVE );
+		}
+		space = true;
+	}
 	if ( strstr( request, "images" ) != NULL ) {
 		if ( !(permissions & ACL_IMAGE_LIST) ) {
 			return sendReply( sock, "403 Forbidden", "text/plain", "No permission to access image list", -1, HTTP_KEEPALIVE );
@@ -142,6 +148,12 @@ static bool handleStatus(int sock, const char *request, int permissions)
 		statisticsJson = json_pack( "{sI}",
 				"runId", randomRunId );
 	}
+	if ( space ) {
+		uint64_t spaceTotal = 0, spaceAvail = 0;
+		file_freeDiskSpace( _basePath, &spaceTotal, &spaceAvail );
+		json_object_set_new( statisticsJson, "spaceTotal", json_integer( spaceTotal ) );
+		json_object_set_new( statisticsJson, "spaceFree", json_integer( spaceAvail ) );
+	}
 	if ( jsonClients != NULL ) {
 		if ( clients ) {
 			json_object_set_new( statisticsJson, "clients", jsonClients );
-- 
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