[sheepdog] [PATCH v3 2/4] sheep: add user-defined free disk space size

[levin li]

From: levin li <xingke.lwp at taobao.com>

Sometimes user doesn't want sheep to use all the disk space,
maybe some space in the same disk is for other use, such as
object cache, or something else, so we can't only get the free
space by syscall, we also should provide a way for users to
specify the free disk space

Signed-off-by: levin li <xingke.lwp at taobao.com>
---
 sheep/sheep.c |   15 ++++++++++++++-
 sheep/store.c |    5 +++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/sheep/sheep.c b/sheep/sheep.c
index 52a294b..3a88c65 100644
--- a/sheep/sheep.c
+++ b/sheep/sheep.c
@@ -47,13 +47,14 @@ static struct option const long_options[] = {
 	{"stdout", no_argument, NULL, 'o'},
 	{"port", required_argument, NULL, 'p'},
 	{"vnodes", required_argument, NULL, 'v'},
+	{"disk-space", required_argument, NULL, 's'},
 	{"enable-cache", required_argument, NULL, 'w'},
 	{"zone", required_argument, NULL, 'z'},
 	{"pidfile", required_argument, NULL, 'P'},
 	{NULL, 0, NULL, 0},
 };
 
-static const char *short_options = "c:dDfghl:op:P:v:w:y:z:";
+static const char *short_options = "c:dDfghl:op:P:v:s:w:y:z:";
 
 static void usage(int status)
 {
@@ -76,6 +77,7 @@ Options:\n\
   -p, --port              specify the TCP port on which to listen\n\
   -P, --pidfile           create a pid file\n\
   -v, --vnodes            specify the number of virtual nodes\n\
+  -s, --disk-space        specify the free disk space in megabytes\n\
   -w, --enable-cache      enable object cache and specify the max cache size in megabytes\n\
   -y, --myaddr            specify the address advertised to other sheep\n\
   -z, --zone              specify the zone id\n\
@@ -187,6 +189,7 @@ int main(int argc, char **argv)
 	char path[PATH_MAX];
 	int64_t zone = -1;
 	int64_t cache_size = 0;
+	int64_t free_space = 0;
 	int nr_vnodes = SD_DEFAULT_VNODES;
 	bool explicit_addr = false;
 	int af;
@@ -283,6 +286,16 @@ int main(int argc, char **argv)
 				exit(1);
 			}
 			break;
+		case 's':
+			free_space = strtoll(optarg, &p, 10);
+			if (optarg == p || free_space <= 0 || UINT64_MAX < free_space) {
+				fprintf(stderr, "Invalid free space size '%s': "
+					"must be an integer between 0 and %lu\n",
+					optarg, UINT64_MAX);
+				exit(1);
+			}
+			sys->disk_space = free_space;
+			break;
 		case 'c':
 			sys->cdrv = find_cdrv(optarg);
 			if (!sys->cdrv) {
diff --git a/sheep/store.c b/sheep/store.c
index d766270..b093916 100644
--- a/sheep/store.c
+++ b/sheep/store.c
@@ -460,6 +460,11 @@ static int init_disk_space(const char *base_path)
 		goto out;
 	}
 
+	if (sys->disk_space) {
+		ret = set_cluster_space(sys->disk_space);
+		goto out;
+	}
+
 	ret = statfs(base_path, &sf);
 	if (ret < 0) {
 		dprintf("get disk space failed %m\n");
-- 
1.7.10