--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#define _LARGEFILE64_SOURCE
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "include/compat.h"
+#include "tools/rbd/ArgumentTypes.h"
+#include "tools/rbd/Shell.h"
+#include "tools/rbd/Utils.h"
+#include "common/safe_io.h"
+#include "common/debug.h"
+#include "common/errno.h"
+#include <iostream>
+#include <boost/program_options.hpp>
+
+#define dout_context g_ceph_context
+#define dout_subsys ceph_subsys_rbd
+
+namespace rbd {
+namespace action {
+namespace merge_diff {
+
+namespace at = argument_types;
+namespace po = boost::program_options;
+
+static int parse_diff_header(int fd, __u8 *tag, string *from, string *to, uint64_t *size)
+{
+ int r;
+
+ {//header
+ char buf[utils::RBD_DIFF_BANNER.size() + 1];
+ r = safe_read_exact(fd, buf, utils::RBD_DIFF_BANNER.size());
+ if (r < 0)
+ return r;
+
+ buf[utils::RBD_DIFF_BANNER.size()] = '\0';
+ if (strcmp(buf, utils::RBD_DIFF_BANNER.c_str())) {
+ std::cerr << "invalid banner '" << buf << "', expected '"
+ << utils::RBD_DIFF_BANNER << "'" << std::endl;
+ return -EINVAL;
+ }
+ }
+
+ while (true) {
+ r = safe_read_exact(fd, tag, 1);
+ if (r < 0)
+ return r;
+
+ if (*tag == RBD_DIFF_FROM_SNAP) {
+ r = utils::read_string(fd, 4096, from); // 4k limit to make sure we don't get a garbage string
+ if (r < 0)
+ return r;
+ dout(2) << " from snap " << *from << dendl;
+ } else if (*tag == RBD_DIFF_TO_SNAP) {
+ r = utils::read_string(fd, 4096, to); // 4k limit to make sure we don't get a garbage string
+ if (r < 0)
+ return r;
+ dout(2) << " to snap " << *to << dendl;
+ } else if (*tag == RBD_DIFF_IMAGE_SIZE) {
+ char buf[8];
+ r = safe_read_exact(fd, buf, 8);
+ if (r < 0)
+ return r;
+
+ bufferlist bl;
+ bl.append(buf, 8);
+ bufferlist::iterator p = bl.begin();
+ ::decode(*size, p);
+ } else {
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int parse_diff_body(int fd, __u8 *tag, uint64_t *offset, uint64_t *length)
+{
+ int r;
+
+ if (!(*tag)) {
+ r = safe_read_exact(fd, tag, 1);
+ if (r < 0)
+ return r;
+ }
+
+ if (*tag == RBD_DIFF_END) {
+ offset = 0;
+ length = 0;
+ return 0;
+ }
+
+ if (*tag != RBD_DIFF_WRITE && *tag != RBD_DIFF_ZERO)
+ return -ENOTSUP;
+
+ char buf[16];
+ r = safe_read_exact(fd, buf, 16);
+ if (r < 0)
+ return r;
+
+ bufferlist bl;
+ bl.append(buf, 16);
+ bufferlist::iterator p = bl.begin();
+ ::decode(*offset, p);
+ ::decode(*length, p);
+
+ if (!(*length))
+ return -ENOTSUP;
+
+ return 0;
+}
+
+/*
+ * fd: the diff file to read from
+ * pd: the diff file to be written into
+ */
+static int accept_diff_body(int fd, int pd, __u8 tag, uint64_t offset, uint64_t length)
+{
+ if (tag == RBD_DIFF_END)
+ return 0;
+
+ bufferlist bl;
+ ::encode(tag, bl);
+ ::encode(offset, bl);
+ ::encode(length, bl);
+ int r;
+ r = bl.write_fd(pd);
+ if (r < 0)
+ return r;
+
+ if (tag == RBD_DIFF_WRITE) {
+ bufferptr bp = buffer::create(length);
+ r = safe_read_exact(fd, bp.c_str(), length);
+ if (r < 0)
+ return r;
+ bufferlist data;
+ data.append(bp);
+ r = data.write_fd(pd);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+/*
+ * Merge two diff files into one single file
+ * Note: It does not do the merging work if
+ * either of the source diff files is stripped,
+ * since which complicates the process and is
+ * rarely used
+ */
+static int do_merge_diff(const char *first, const char *second,
+ const char *path, bool no_progress)
+{
+ utils::ProgressContext pc("Merging image diff", no_progress);
+ int fd = -1, sd = -1, pd = -1, r;
+
+ string f_from, f_to;
+ string s_from, s_to;
+ uint64_t f_size = 0;
+ uint64_t s_size = 0;
+ uint64_t pc_size;
+
+ __u8 f_tag = 0, s_tag = 0;
+ uint64_t f_off = 0, f_len = 0;
+ uint64_t s_off = 0, s_len = 0;
+ bool f_end = false, s_end = false;
+
+ bool first_stdin = !strcmp(first, "-");
+ if (first_stdin) {
+ fd = STDIN_FILENO;
+ } else {
+ fd = open(first, O_RDONLY);
+ if (fd < 0) {
+ r = -errno;
+ std::cerr << "rbd: error opening " << first << std::endl;
+ goto done;
+ }
+ }
+
+ sd = open(second, O_RDONLY);
+ if (sd < 0) {
+ r = -errno;
+ std::cerr << "rbd: error opening " << second << std::endl;
+ goto done;
+ }
+
+ if (strcmp(path, "-") == 0) {
+ pd = 1;
+ } else {
+ pd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0644);
+ if (pd < 0) {
+ r = -errno;
+ std::cerr << "rbd: error create " << path << std::endl;
+ goto done;
+ }
+ }
+
+ //We just handle the case like 'banner, [ftag], [ttag], stag, [wztag]*,etag',
+ // and the (offset,length) in wztag must be ascending order.
+ r = parse_diff_header(fd, &f_tag, &f_from, &f_to, &f_size);
+ if (r < 0) {
+ std::cerr << "rbd: failed to parse first diff header" << std::endl;
+ goto done;
+ }
+
+ r = parse_diff_header(sd, &s_tag, &s_from, &s_to, &s_size);
+ if (r < 0) {
+ std::cerr << "rbd: failed to parse second diff header" << std::endl;
+ goto done;
+ }
+
+ if (f_to != s_from) {
+ r = -EINVAL;
+ std::cerr << "The first TO snapshot must be equal with the second FROM "
+ << "snapshot, aborting" << std::endl;
+ goto done;
+ }
+
+ {
+ // header
+ bufferlist bl;
+ bl.append(utils::RBD_DIFF_BANNER);
+
+ __u8 tag;
+ if (f_from.size()) {
+ tag = RBD_DIFF_FROM_SNAP;
+ ::encode(tag, bl);
+ ::encode(f_from, bl);
+ }
+
+ if (s_to.size()) {
+ tag = RBD_DIFF_TO_SNAP;
+ ::encode(tag, bl);
+ ::encode(s_to, bl);
+ }
+
+ tag = RBD_DIFF_IMAGE_SIZE;
+ ::encode(tag, bl);
+ ::encode(s_size, bl);
+
+ r = bl.write_fd(pd);
+ if (r < 0) {
+ std::cerr << "rbd: failed to write merged diff header" << std::endl;
+ goto done;
+ }
+ }
+ if (f_size > s_size)
+ pc_size = f_size << 1;
+ else
+ pc_size = s_size << 1;
+
+ //data block
+ while (!f_end || !s_end) {
+ // progress through input
+ pc.update_progress(f_off + s_off, pc_size);
+
+ if (!f_end && !f_len) {
+ uint64_t last_off = f_off;
+
+ r = parse_diff_body(fd, &f_tag, &f_off, &f_len);
+ dout(2) << "first diff data chunk: tag=" << f_tag << ", "
+ << "off=" << f_off << ", "
+ << "len=" << f_len << dendl;
+ if (r < 0) {
+ std::cerr << "rbd: failed to read first diff data chunk header"
+ << std::endl;
+ goto done;
+ }
+
+ if (f_tag == RBD_DIFF_END) {
+ f_end = true;
+ f_tag = RBD_DIFF_ZERO;
+ f_off = f_size;
+ if (f_size < s_size)
+ f_len = s_size - f_size;
+ else
+ f_len = 0;
+ }
+
+ if (last_off > f_off) {
+ r = -ENOTSUP;
+ std::cerr << "rbd: out-of-order offset from first diff ("
+ << last_off << " > " << f_off << ")" << std::endl;
+ goto done;
+ }
+ }
+
+ if (!s_end && !s_len) {
+ uint64_t last_off = s_off;
+
+ r = parse_diff_body(sd, &s_tag, &s_off, &s_len);
+ dout(2) << "second diff data chunk: tag=" << s_tag << ", "
+ << "off=" << s_off << ", "
+ << "len=" << s_len << dendl;
+ if (r < 0) {
+ std::cerr << "rbd: failed to read second diff data chunk header"
+ << std::endl;
+ goto done;
+ }
+
+ if (s_tag == RBD_DIFF_END) {
+ s_end = true;
+ s_off = s_size;
+ if (s_size < f_size)
+ s_len = f_size - s_size;
+ else
+ s_len = 0;
+ }
+
+ if (last_off > s_off) {
+ r = -ENOTSUP;
+ std::cerr << "rbd: out-of-order offset from second diff ("
+ << last_off << " > " << s_off << ")" << std::endl;
+ goto done;
+ }
+ }
+
+ if (f_off < s_off && f_len) {
+ uint64_t delta = s_off - f_off;
+ if (delta > f_len)
+ delta = f_len;
+ r = accept_diff_body(fd, pd, f_tag, f_off, delta);
+ if (r < 0) {
+ std::cerr << "rbd: failed to merge diff chunk" << std::endl;
+ goto done;
+ }
+ f_off += delta;
+ f_len -= delta;
+
+ if (!f_len) {
+ f_tag = 0;
+ continue;
+ }
+ }
+ assert(f_off >= s_off);
+
+ if (f_off < s_off + s_len && f_len) {
+ uint64_t delta = s_off + s_len - f_off;
+ if (delta > f_len)
+ delta = f_len;
+ if (f_tag == RBD_DIFF_WRITE) {
+ if (first_stdin) {
+ bufferptr bp = buffer::create(delta);
+ r = safe_read_exact(fd, bp.c_str(), delta);
+ } else {
+ off64_t l = lseek64(fd, delta, SEEK_CUR);
+ r = l < 0 ? -errno : 0;
+ }
+ if (r < 0) {
+ std::cerr << "rbd: failed to skip first diff data" << std::endl;
+ goto done;
+ }
+ }
+ f_off += delta;
+ f_len -= delta;
+
+ if (!f_len) {
+ f_tag = 0;
+ continue;
+ }
+ }
+ assert(f_off >= s_off + s_len);
+ if (s_len) {
+ r = accept_diff_body(sd, pd, s_tag, s_off, s_len);
+ if (r < 0) {
+ std::cerr << "rbd: failed to merge diff chunk" << std::endl;
+ goto done;
+ }
+ s_off += s_len;
+ s_len = 0;
+ s_tag = 0;
+ } else {
+ assert(f_end && s_end);
+ }
+ continue;
+ }
+
+ {//tail
+ __u8 tag = RBD_DIFF_END;
+ bufferlist bl;
+ ::encode(tag, bl);
+ r = bl.write_fd(pd);
+ }
+
+done:
+ if (pd > 2)
+ close(pd);
+ if (sd > 2)
+ close(sd);
+ if (fd > 2)
+ close(fd);
+
+ if(r < 0) {
+ pc.fail();
+ if (pd > 2)
+ unlink(path);
+ } else
+ pc.finish();
+
+ return r;
+}
+
+void get_arguments(po::options_description *positional,
+ po::options_description *options) {
+ positional->add_options()
+ ("diff1-path", "path to first diff (or '-' for stdin)")
+ ("diff2-path", "path to second diff");
+ at::add_path_options(positional, options,
+ "path to merged diff (or '-' for stdout)");
+ at::add_no_progress_option(options);
+}
+
+int execute(const po::variables_map &vm) {
+ std::string first_diff = utils::get_positional_argument(vm, 0);
+ if (first_diff.empty()) {
+ std::cerr << "rbd: first diff was not specified" << std::endl;
+ return -EINVAL;
+ }
+
+ std::string second_diff = utils::get_positional_argument(vm, 1);
+ if (second_diff.empty()) {
+ std::cerr << "rbd: second diff was not specified" << std::endl;
+ return -EINVAL;
+ }
+
+ std::string path;
+ int r = utils::get_path(vm, utils::get_positional_argument(vm, 2),
+ &path);
+ if (r < 0) {
+ return r;
+ }
+
+ r = do_merge_diff(first_diff.c_str(), second_diff.c_str(), path.c_str(),
+ vm[at::NO_PROGRESS].as<bool>());
+ if (r < 0) {
+ cerr << "rbd: merge-diff error" << std::endl;
+ return -r;
+ }
+
+ return 0;
+}
+
+Shell::Action action(
+ {"merge-diff"}, {}, "Merge two diff exports together.", "",
+ &get_arguments, &execute);
+
+} // namespace merge_diff
+} // namespace action
+} // namespace rbd
Code Review / stor4nfv.git / blobdiff