[sheepdog] [PATCH v6 10/16] collie/farm: implement snap object
Kai Zhang
kyle at zelin.io
Tue May 21 12:11:12 CEST 2013
moved snap.c from sheep/farm to collie/farm
Changes:
1. Snap also saves a "tag" to snap_log, so that user can load a snapshot by specify a tag
2. Epoch info is not necessary, use index instead. User can use either tag or index to select a snapshot to load
3. Construct snap_log_path during snap_init(). snap_init() will be called by farm_init().
4. Fix style problems.
5. Replaced sd_xprintf(...) with fprintf(...)
Signed-off-by: Kai Zhang <kyle at zelin.io>
---
collie/Makefile.am | 2 +-
collie/farm/farm.h | 8 ++++
{sheep => collie}/farm/snap.c | 75 +++++++++++++++++++---------------------
include/sheepdog_proto.h | 10 +++--
4 files changed, 51 insertions(+), 44 deletions(-)
rename {sheep => collie}/farm/snap.c (62%)
diff --git a/collie/Makefile.am b/collie/Makefile.am
index 5a705b2..8cab2a3 100644
--- a/collie/Makefile.am
+++ b/collie/Makefile.am
@@ -23,7 +23,7 @@ INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include
sbin_PROGRAMS = collie
-collie_SOURCES = farm/object_tree.c farm/sha1_file.c \
+collie_SOURCES = farm/object_tree.c farm/sha1_file.c farm/snap.c \
collie.c common.c treeview.c vdi.c node.c cluster.c
if BUILD_TRACE
diff --git a/collie/farm/farm.h b/collie/farm/farm.h
index cd1fa26..451ebea 100644
--- a/collie/farm/farm.h
+++ b/collie/farm/farm.h
@@ -43,6 +43,14 @@ static inline char *get_object_directory(void)
typedef int (*object_handler_func_t)(uint64_t oid, int nr_copies, void *buf,
size_t size, void *data);
+/* snap.c */
+int snap_init(const char *path);
+void *snap_file_read(unsigned char *sha1, struct sha1_file_hdr *outhdr);
+int snap_file_write(uint32_t idx, unsigned char *trunksha1,
+ unsigned char *outsha1);
+void *snap_log_read(int *out_nr);
+int snap_log_write(uint32_t idx, const char *tag, unsigned char *sha1);
+
/* sha1_file.c */
int sha1_file_write(unsigned char *buf, unsigned len, unsigned char *);
void *sha1_file_read(const unsigned char *sha1, struct sha1_file_hdr *);
diff --git a/sheep/farm/snap.c b/collie/farm/snap.c
similarity index 62%
rename from sheep/farm/snap.c
rename to collie/farm/snap.c
index 0cc18ba..9f8370e 100644
--- a/sheep/farm/snap.c
+++ b/collie/farm/snap.c
@@ -1,7 +1,9 @@
/*
* Copyright (C) 2011 Taobao Inc.
+ * Copyright (C) 2013 Zelin.io
*
* Liu Yuan <namei.unix at gmail.com>
+ * Kai Zhang <kyle at zelin.io>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
@@ -12,52 +14,54 @@
*/
/*
- * Snap object is the meta data that describes the snapshot, either triggered
- * by recovery logic or end users.
+ * Snap object is the meta data that describes the cluster snapshot.
*/
#include <time.h>
#include <sys/stat.h>
#include <unistd.h>
#include "farm.h"
-#include "sheep_priv.h"
-int snap_init(void)
+static char snap_log_path[PATH_MAX];
+
+int snap_init(const char *farm_dir)
{
- int fd, ret = 0;
+ int fd, ret = -1;
struct strbuf buf = STRBUF_INIT;
strbuf_addstr(&buf, farm_dir);
strbuf_addf(&buf, "/%s", "user_snap");
- fd = open(buf.buf, O_CREAT | O_EXCL, 0666);
+ if (!strlen(snap_log_path))
+ strbuf_copyout(&buf, snap_log_path, sizeof(snap_log_path));
+
+ fd = open(snap_log_path, O_CREAT | O_EXCL, 0666);
if (fd < 0) {
if (errno != EEXIST) {
- ret = -1;
+ fprintf(stderr, "%m\n");
goto out;
}
- } else
- close(fd);
+ }
+ ret = 0;
+ close(fd);
out:
strbuf_release(&buf);
return ret;
}
-int snap_log_write(uint32_t epoch, unsigned char *sha1)
+int snap_log_write(uint32_t idx, const char *tag, unsigned char *sha1)
{
int fd, ret = -1;
struct strbuf buf = STRBUF_INIT;
- struct snap_log log = { .epoch = epoch,
+ struct snap_log log = { .idx = idx,
.time = time(NULL) };
-
+ pstrcpy(log.tag, SD_MAX_SNAPSHOT_TAG_LEN, tag);
memcpy(log.sha1, sha1, SHA1_LEN);
- strbuf_addstr(&buf, farm_dir);
- strbuf_addf(&buf, "/%s", "user_snap");
- fd = open(buf.buf, O_WRONLY | O_APPEND);
+ fd = open(snap_log_path, O_WRONLY | O_APPEND);
if (fd < 0) {
- sd_dprintf("%m");
+ fprintf(stderr, "%m\n");
goto out;
}
@@ -65,8 +69,10 @@ int snap_log_write(uint32_t epoch, unsigned char *sha1)
strbuf_add(&buf, &log, sizeof(log));
ret = xwrite(fd, buf.buf, buf.len);
if (ret != buf.len)
- ret = -1;
+ goto out_close;
+ ret = 0;
+out_close:
close(fd);
out:
strbuf_release(&buf);
@@ -75,21 +81,17 @@ out:
void *snap_log_read(int *out_nr)
{
- struct strbuf buf = STRBUF_INIT;
struct stat st;
void *buffer = NULL;
int len, fd;
- strbuf_addstr(&buf, farm_dir);
- strbuf_addf(&buf, "/%s", "user_snap");
-
- fd = open(buf.buf, O_RDONLY);
+ fd = open(snap_log_path, O_RDONLY);
if (fd < 0) {
- sd_dprintf("%m");
+ fprintf(stderr, "%m\n");
goto out;
}
if (fstat(fd, &st) < 0) {
- sd_dprintf("%m");
+ fprintf(stderr, "%m\n");
goto out_close;
}
@@ -105,7 +107,6 @@ void *snap_log_read(int *out_nr)
out_close:
close(fd);
out:
- strbuf_release(&buf);
return buffer;
}
@@ -113,7 +114,6 @@ void *snap_file_read(unsigned char *sha1, struct sha1_file_hdr *outhdr)
{
void *buffer = NULL;
- sd_dprintf("%s", sha1_to_hex(sha1));
buffer = sha1_file_read(sha1, outhdr);
if (!buffer)
return NULL;
@@ -125,28 +125,25 @@ void *snap_file_read(unsigned char *sha1, struct sha1_file_hdr *outhdr)
return buffer;
}
-int snap_file_write(uint32_t epoch, struct sd_node *nodes, int nr_nodes,
- unsigned char *trunksha1, unsigned char *outsha1)
+int snap_file_write(uint32_t idx, unsigned char *trunksha1,
+ unsigned char *outsha1)
{
- int ret = 0;
- struct strbuf buf = STRBUF_INIT;
+ int ret = -1;
struct sha1_file_hdr hdr = {};
+ struct strbuf buf = STRBUF_INIT;
memcpy(hdr.tag, TAG_SNAP, TAG_LEN);
- hdr.size = nr_nodes * sizeof(*nodes) + SHA1_LEN;
- hdr.priv = epoch;
+ hdr.size = SHA1_LEN;
+ hdr.priv = idx;
hdr.reserved = 0;
strbuf_add(&buf, &hdr, sizeof(hdr));
strbuf_add(&buf, trunksha1, SHA1_LEN);
- strbuf_add(&buf, (char *)nodes, nr_nodes * sizeof(*nodes));
- if (sha1_file_write((void *)buf.buf, buf.len, outsha1) < 0) {
- ret = -1;
- goto err;
- }
+ if (sha1_file_write((void *)buf.buf, buf.len, outsha1) < 0)
+ goto out;
- sd_dprintf("epoch: %" PRIu32 ", sha1: %s", epoch, sha1_to_hex(outsha1));
-err:
+ ret = 0;
+out:
strbuf_release(&buf);
return ret;
}
diff --git a/include/sheepdog_proto.h b/include/sheepdog_proto.h
index e211ce3..5440721 100644
--- a/include/sheepdog_proto.h
+++ b/include/sheepdog_proto.h
@@ -95,6 +95,7 @@
#define SD_MAX_VDI_TAG_LEN 256U
#define SD_MAX_VDI_ATTR_KEY_LEN 256U
#define SD_MAX_VDI_ATTR_VALUE_LEN 65536U
+#define SD_MAX_SNAPSHOT_TAG_LEN 256U
#define SD_NR_VDIS (1U << 24)
#define SD_DATA_OBJ_SIZE (UINT64_C(1) << 22)
#define SD_MAX_VDI_SIZE (SD_DATA_OBJ_SIZE * MAX_DATA_OBJS)
@@ -221,7 +222,8 @@ struct sheepdog_vdi_attr {
#define SHA1_LEN 20
struct snap_log {
- uint32_t epoch;
+ uint32_t idx;
+ char tag[SD_MAX_SNAPSHOT_TAG_LEN];
uint64_t time;
unsigned char sha1[SHA1_LEN];
};
@@ -319,9 +321,9 @@ static inline bool vdi_is_snapshot(const struct sd_inode *inode)
static inline __attribute__((used)) void __sd_proto_build_bug_ons(void)
{
- /* never called, only for checking BUILD_BUG_ON()s */
- BUILD_BUG_ON(sizeof(struct sd_req) != SD_REQ_SIZE);
- BUILD_BUG_ON(sizeof(struct sd_rsp) != SD_RSP_SIZE);
+ /* never called, only for checking BUILD_BUG_ON()s */
+ BUILD_BUG_ON(sizeof(struct sd_req) != SD_REQ_SIZE);
+ BUILD_BUG_ON(sizeof(struct sd_rsp) != SD_RSP_SIZE);
}
#endif
--
1.7.1
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