[sheepdog] [PATCH 1/4] sheep: get the free disk space and store it in the config file

[levin li]

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

We only specify the free disk space for the first boot, after that
we store the size into the config file.

Signed-off-by: levin li <xingke.lwp at taobao.com>
---
 sheep/sheep_priv.h |    3 ++
 sheep/store.c      |   81 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+), 0 deletions(-)

diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
index c4225ea..692169d 100644
--- a/sheep/sheep_priv.h
+++ b/sheep/sheep_priv.h
@@ -88,6 +88,7 @@ struct cluster_info {
 	uint16_t flags;
 
 	uint64_t cache_size;
+	uint64_t disk_space;
 
 	/*
 	 * List of nodes that were past of the last epoch before a shutdown,
@@ -247,6 +248,8 @@ int set_cluster_flags(uint16_t flags);
 int get_cluster_flags(uint16_t *flags);
 int set_cluster_store(const char *name);
 int get_cluster_store(char *buf);
+int set_cluster_space(uint32_t space);
+int get_cluster_space(uint32_t *space);
 
 int store_file_write(void *buffer, size_t len);
 void *store_file_read(void);
diff --git a/sheep/store.c b/sheep/store.c
index ddb9511..2c2f94b 100644
--- a/sheep/store.c
+++ b/sheep/store.c
@@ -16,6 +16,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <poll.h>
+#include <sys/vfs.h>
 #include <sys/statvfs.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -29,6 +30,7 @@
 
 struct sheepdog_config {
 	uint64_t ctime;
+	uint32_t space;
 	uint16_t flags;
 	uint8_t copies;
 	uint8_t store[STORE_LEN];
@@ -443,6 +445,32 @@ static int init_store_driver(void)
 	return sd_store->init(obj_path);
 }
 
+static int init_disk_space(const char *base_path)
+{
+	int ret = SD_RES_SUCCESS;
+	uint32_t space_size = 0;
+	struct statfs sf;
+
+	ret = get_cluster_space(&space_size);
+	if (space_size != 0) {
+		sys->disk_space = space_size;
+		goto out;
+	}
+
+	ret = statfs(base_path, &sf);
+	if (ret < 0) {
+		dprintf("get disk space failed %m\n");
+		ret = SD_RES_EIO;
+		goto out;
+	}
+
+	sys->disk_space = sf.f_bfree * 4 / 1024;
+	ret = set_cluster_space(sys->disk_space);
+out:
+	dprintf("disk free space is %" PRIu64 "M\n", sys->disk_space);
+	return ret;
+}
+
 int init_store(const char *d, int enable_write_cache)
 {
 	int ret;
@@ -467,6 +495,10 @@ int init_store(const char *d, int enable_write_cache)
 	if (ret)
 		return ret;
 
+	ret = init_disk_space(d);
+	if (ret)
+		return ret;
+
 	if (!sys->gateway_only) {
 		ret = init_store_driver();
 		if (ret)
@@ -716,3 +748,52 @@ int get_cluster_store(char *buf)
 out:
 	return ret;
 }
+
+int set_cluster_space(uint32_t space)
+{
+	int fd, ret = SD_RES_EIO;
+	void *jd;
+
+	fd = open(config_path, O_DSYNC | O_WRONLY);
+	if (fd < 0)
+		goto out;
+
+	jd = jrnl_begin(&space, sizeof(space),
+			offsetof(struct sheepdog_config, space),
+			config_path, jrnl_path);
+	if (!jd) {
+		ret = SD_RES_EIO;
+		goto err;
+	}
+	ret = xpwrite(fd, &space, sizeof(space),
+		      offsetof(struct sheepdog_config, space));
+	if (ret != sizeof(space))
+		ret = SD_RES_EIO;
+	else
+		ret = SD_RES_SUCCESS;
+	jrnl_end(jd);
+err:
+	close(fd);
+out:
+	return ret;
+}
+
+int get_cluster_space(uint32_t *space)
+{
+	int fd, ret = SD_RES_EIO;
+
+	fd = open(config_path, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	ret = xpread(fd, space, sizeof(*space),
+		     offsetof(struct sheepdog_config, space));
+	if (ret != sizeof(*space))
+		ret = SD_RES_EIO;
+	else
+		ret = SD_RES_SUCCESS;
+
+	close(fd);
+out:
+	return ret;
+}
-- 
1.7.1