[Sheepdog] [PATCH v2 03/15] sheepfs: core infrastructure
Liu Yuan
namei.unix at gmail.com
Mon May 14 11:47:28 CEST 2012
From: Liu Yuan <tailai.ly at taobao.com>
Sheepfs is FUSE-based pseudo file system in userland to access both sheepdog's
internal state (for e.g, cluster info, vdi list) as well as sheepdog's high
reliable stroage.
This building block is supposed to be modular enough to allow us ease adding
more powerful tools.
Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
sheepfs/Makefile.am | 8 +-
sheepfs/core.c | 293 +++++++++++++++++++++++++++++++++++++++++++++++++++
sheepfs/sheepfs.h | 13 +++
3 files changed, 310 insertions(+), 4 deletions(-)
create mode 100644 sheepfs/core.c
create mode 100644 sheepfs/sheepfs.h
diff --git a/sheepfs/Makefile.am b/sheepfs/Makefile.am
index 0d4a42c..c6c6741 100644
--- a/sheepfs/Makefile.am
+++ b/sheepfs/Makefile.am
@@ -17,18 +17,18 @@
MAINTAINERCLEANFILES = Makefile.in
-AM_CFLAGS =
+AM_CFLAGS = $(fuse_CFLAGS) -DFUSE_USE_VERSION=26
INCLUDES = -I$(top_builddir)/include -I$(top_srcdir)/include
sbin_PROGRAMS = sheepfs
-sheepfs_SOURCES =
+sheepfs_SOURCES = core.c
-sheepfs_LDADD = ../lib/libsheepdog.a
+sheepfs_LDADD = ../lib/libsheepdog.a $(fuse_LIBS) $(LIBS)
sheepfs_DEPENDENCIES = ../lib/libsheepdog.a
-noinst_HEADERS =
+noinst_HEADERS = sheepfs.h
EXTRA_DIST =
diff --git a/sheepfs/core.c b/sheepfs/core.c
new file mode 100644
index 0000000..230794d
--- /dev/null
+++ b/sheepfs/core.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (C) 2012 Taobao Inc.
+ *
+ * Liu Yuan <namei.unix at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <fuse.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <attr/xattr.h>
+#include <dirent.h>
+#include <pthread.h>
+#include <getopt.h>
+#include <syslog.h>
+
+#include "strbuf.h"
+#include "util.h"
+#include "sheepfs.h"
+
+#define SH_OP_NAME "user.sheepfs.opcode"
+#define SH_OP_SIZE sizeof(uint32_t)
+
+char sheepfs_shadow[PATH_MAX];
+
+static int sheepfs_debug;
+static int sheepfs_fg;
+
+static struct option const long_options[] = {
+ {"debug", no_argument, NULL, 'd'},
+ {"directio", no_argument, NULL, 'D'},
+ {"help", no_argument, NULL, 'h'},
+ {"foreground", no_argument, NULL, 'f'},
+ {NULL, 0, NULL, 0},
+};
+
+static const char *short_options = "dDhf";
+
+static struct sheepfs_file_operation {
+ int (*read)(const char *path, char *buf, size_t size, off_t);
+ int (*write)(const char *path, const char *buf, size_t size, off_t);
+ size_t (*get_size)(const char *path);
+} sheepfs_file_ops[] = {
+ [OP_NULL] = { NULL, NULL, NULL },
+};
+
+int sheepfs_set_op(const char *path, unsigned opcode)
+{
+ if (shadow_file_setxattr(path, SH_OP_NAME, &opcode, SH_OP_SIZE) < 0) {
+ shadow_file_delete(path);
+ return -1;
+ }
+ return 0;
+}
+
+static unsigned sheepfs_get_op(const char *path)
+{
+ unsigned opcode = 0;
+
+ /* If fail, we simply return 0 to run NULL operation */
+ shadow_file_getxattr(path, SH_OP_NAME, &opcode, SH_OP_SIZE);
+
+ return opcode;
+}
+
+static size_t sheepfs_get_size(const char *path)
+{
+ unsigned op = sheepfs_get_op(path);
+
+ if (sheepfs_file_ops[op].get_size)
+ return sheepfs_file_ops[op].get_size(path);
+
+ return 0;
+}
+
+static int sheepfs_getattr(const char *path, struct stat *st)
+{
+ struct strbuf p = STRBUF_INIT;
+ int ret;
+
+ strbuf_addf(&p, "%s%s", sheepfs_shadow, path);
+ ret = stat(p.buf, st);
+ if (ret < 0) {
+ ret = -errno;
+ goto out;
+ }
+ if (S_ISREG(st->st_mode))
+ st->st_size = sheepfs_get_size(path);
+out:
+ strbuf_release(&p);
+ return ret;
+}
+
+static int sheepfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
+ off_t offset, struct fuse_file_info *fi)
+{
+ DIR *dir;
+ struct dirent *dentry;
+ struct strbuf p = STRBUF_INIT;
+ int ret = 0;
+
+ strbuf_addf(&p, "%s%s", sheepfs_shadow, path);
+ dir = opendir(p.buf);
+ if (!dir) {
+ ret = -errno;
+ syslog(LOG_ERR, "[%s] %m\n", __func__);
+ goto out;
+ }
+
+ while ((dentry = readdir(dir))) {
+ if (filler(buf, dentry->d_name, NULL, 0) != 0) {
+ syslog(LOG_ERR, "[%s] out of memory\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+out:
+ strbuf_release(&p);
+ return ret;
+}
+
+static int sheepfs_read(const char *path, char *buf, size_t size,
+ off_t offset, struct fuse_file_info *fi)
+{
+ int ret = 0;
+ unsigned op = sheepfs_get_op(path);
+
+ if (sheepfs_file_ops[op].read)
+ ret = sheepfs_file_ops[op].read(path, buf, size, offset);
+
+ return ret;
+}
+
+static int sheepfs_write(const char *path, const char *buf, size_t size,
+ off_t offset, struct fuse_file_info *fi)
+{
+ int ret = 0;
+ unsigned op = sheepfs_get_op(path);
+
+ if (sheepfs_file_ops[op].write)
+ ret = sheepfs_file_ops[op].write(path, buf, size, offset);
+
+ return ret;
+}
+
+static int sheepfs_truncate(const char *path, off_t size)
+{
+ struct strbuf p = STRBUF_INIT;
+ int ret = 0, fd;
+
+ strbuf_addf(&p, "%s%s", sheepfs_shadow, path);
+ fd = open(p.buf, O_RDWR);
+ if (fd < 0)
+ ret = -ENOENT;
+ else
+ close(fd);
+
+ strbuf_release(&p);
+ return ret;
+}
+
+struct fuse_operations sheepfs_ops = {
+ .getattr = sheepfs_getattr,
+ .readdir = sheepfs_readdir,
+ .truncate = sheepfs_truncate,
+ .read = sheepfs_read,
+ .write = sheepfs_write,
+};
+
+static int sheepfs_main_loop(char *mountpoint)
+{
+ struct fuse_args args = FUSE_ARGS_INIT(0, NULL);
+ int ret = -1;
+
+ fuse_opt_add_arg(&args, "sheepfs"); /* placeholder for argv[0] */
+ fuse_opt_add_arg(&args, "-ofsname=sheepfs");
+ fuse_opt_add_arg(&args, mountpoint);
+ if (sheepfs_debug)
+ fuse_opt_add_arg(&args, "-odebug");
+ if (sheepfs_fg)
+ fuse_opt_add_arg(&args, "-f");
+
+ syslog(LOG_INFO, "sheepfs daemon started\n");
+ ret = fuse_main(args.argc, args.argv, &sheepfs_ops, NULL);
+ rmdir_r(sheepfs_shadow);
+ syslog(LOG_INFO, "sheepfs daemon exited %d\n", ret);
+ return ret;
+}
+
+static int create_sheepfs_layout(char *path)
+{
+ return 0;
+}
+
+static void usage(int inval)
+{
+ if (inval)
+ fprintf(stderr, "Try 'sheepfs --help' for help.\n");
+ else
+ printf("\
+Usage: sheepfs [OPTION]... MOUNTPOINT\n\
+Options:\n\
+ -d, --debug enable debug output (implies -f)\n\
+ -D, --directio use direct IO to access volume\n\
+ -f, --foreground sheepfs run in the foreground\n\
+ -h, --help display this help and exit\n\
+");
+ exit(inval);
+}
+
+int main(int argc, char **argv)
+{
+ struct strbuf path = STRBUF_INIT;
+ int ch, longindex;
+ char *dir = NULL, *cwd;
+
+
+ while ((ch = getopt_long(argc, argv, short_options, long_options,
+ &longindex)) >= 0) {
+ switch (ch) {
+ case 'd':
+ sheepfs_debug = 1;
+ break;
+ case 'D':
+ break;
+ case 'h':
+ usage(0);
+ break;
+ case 'f':
+ sheepfs_fg = 1;
+ break;
+ default:
+ usage(1);
+ }
+ }
+
+ if (optind != argc)
+ dir = argv[optind];
+ else
+ usage(1);
+
+ cwd = get_current_dir_name();
+ if (!cwd) {
+ fprintf(stderr, "%m\n");
+ exit(1);
+ }
+ strbuf_addf(&path, "%s/%s", cwd, ".sheepfs");
+ free(cwd);
+ memcpy(sheepfs_shadow, path.buf, path.len);
+ if (mkdir(sheepfs_shadow, 0755) < 0) {
+ if (errno != EEXIST) {
+ fprintf(stderr, "%m\n");
+ exit(1);
+ }
+ }
+
+ strbuf_release(&path);
+ create_sheepfs_layout();
+ openlog("sheepfs", LOG_CONS | LOG_PID, LOG_DAEMON);
+
+ return sheepfs_main_loop(dir);
+}
+
+struct strbuf *sheepfs_run_cmd(const char *command)
+{
+ struct strbuf *buf = xmalloc(sizeof(*buf));
+ FILE *f = popen(command, "re");
+
+ if (!f) {
+ syslog(LOG_ERR, "[%s] popen failed\n", __func__);
+ goto err;
+ }
+
+ strbuf_init(buf, 4096);
+
+ while (!feof(f))
+ strbuf_fread(buf, 4096, f);
+
+ pclose(f);
+ return buf;
+err:
+ strbuf_release(buf);
+ pclose(f);
+ free(buf);
+ return NULL;
+}
diff --git a/sheepfs/sheepfs.h b/sheepfs/sheepfs.h
new file mode 100644
index 0000000..d1b2a14
--- /dev/null
+++ b/sheepfs/sheepfs.h
@@ -0,0 +1,13 @@
+#ifndef SHEEPFS_H
+#define SHEEPFS_H
+
+enum sheepfs_opcode {
+ OP_NULL = 0,
+};
+
+extern char sheepfs_shadow[];
+
+extern struct strbuf *sheepfs_run_cmd(const char *command);
+extern int sheepfs_set_op(const char *path, unsigned opcode);
+
+#endif
--
1.7.8.2
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