1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
2 // vim: ts=8 sw=2 smarttab
4 #define _LARGEFILE64_SOURCE
8 #include "include/compat.h"
9 #include "tools/rbd/ArgumentTypes.h"
10 #include "tools/rbd/Shell.h"
11 #include "tools/rbd/Utils.h"
12 #include "common/safe_io.h"
13 #include "common/debug.h"
14 #include "common/errno.h"
16 #include <boost/program_options.hpp>
18 #define dout_context g_ceph_context
19 #define dout_subsys ceph_subsys_rbd
23 namespace merge_diff {
25 namespace at = argument_types;
26 namespace po = boost::program_options;
28 static int parse_diff_header(int fd, __u8 *tag, string *from, string *to, uint64_t *size)
33 char buf[utils::RBD_DIFF_BANNER.size() + 1];
34 r = safe_read_exact(fd, buf, utils::RBD_DIFF_BANNER.size());
38 buf[utils::RBD_DIFF_BANNER.size()] = '\0';
39 if (strcmp(buf, utils::RBD_DIFF_BANNER.c_str())) {
40 std::cerr << "invalid banner '" << buf << "', expected '"
41 << utils::RBD_DIFF_BANNER << "'" << std::endl;
47 r = safe_read_exact(fd, tag, 1);
51 if (*tag == RBD_DIFF_FROM_SNAP) {
52 r = utils::read_string(fd, 4096, from); // 4k limit to make sure we don't get a garbage string
55 dout(2) << " from snap " << *from << dendl;
56 } else if (*tag == RBD_DIFF_TO_SNAP) {
57 r = utils::read_string(fd, 4096, to); // 4k limit to make sure we don't get a garbage string
60 dout(2) << " to snap " << *to << dendl;
61 } else if (*tag == RBD_DIFF_IMAGE_SIZE) {
63 r = safe_read_exact(fd, buf, 8);
69 bufferlist::iterator p = bl.begin();
79 static int parse_diff_body(int fd, __u8 *tag, uint64_t *offset, uint64_t *length)
84 r = safe_read_exact(fd, tag, 1);
89 if (*tag == RBD_DIFF_END) {
95 if (*tag != RBD_DIFF_WRITE && *tag != RBD_DIFF_ZERO)
99 r = safe_read_exact(fd, buf, 16);
105 bufferlist::iterator p = bl.begin();
106 ::decode(*offset, p);
107 ::decode(*length, p);
116 * fd: the diff file to read from
117 * pd: the diff file to be written into
119 static int accept_diff_body(int fd, int pd, __u8 tag, uint64_t offset, uint64_t length)
121 if (tag == RBD_DIFF_END)
126 ::encode(offset, bl);
127 ::encode(length, bl);
133 if (tag == RBD_DIFF_WRITE) {
134 bufferptr bp = buffer::create(length);
135 r = safe_read_exact(fd, bp.c_str(), length);
140 r = data.write_fd(pd);
149 * Merge two diff files into one single file
150 * Note: It does not do the merging work if
151 * either of the source diff files is stripped,
152 * since which complicates the process and is
155 static int do_merge_diff(const char *first, const char *second,
156 const char *path, bool no_progress)
158 utils::ProgressContext pc("Merging image diff", no_progress);
159 int fd = -1, sd = -1, pd = -1, r;
167 __u8 f_tag = 0, s_tag = 0;
168 uint64_t f_off = 0, f_len = 0;
169 uint64_t s_off = 0, s_len = 0;
170 bool f_end = false, s_end = false;
172 bool first_stdin = !strcmp(first, "-");
176 fd = open(first, O_RDONLY);
179 std::cerr << "rbd: error opening " << first << std::endl;
184 sd = open(second, O_RDONLY);
187 std::cerr << "rbd: error opening " << second << std::endl;
191 if (strcmp(path, "-") == 0) {
194 pd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0644);
197 std::cerr << "rbd: error create " << path << std::endl;
202 //We just handle the case like 'banner, [ftag], [ttag], stag, [wztag]*,etag',
203 // and the (offset,length) in wztag must be ascending order.
204 r = parse_diff_header(fd, &f_tag, &f_from, &f_to, &f_size);
206 std::cerr << "rbd: failed to parse first diff header" << std::endl;
210 r = parse_diff_header(sd, &s_tag, &s_from, &s_to, &s_size);
212 std::cerr << "rbd: failed to parse second diff header" << std::endl;
216 if (f_to != s_from) {
218 std::cerr << "The first TO snapshot must be equal with the second FROM "
219 << "snapshot, aborting" << std::endl;
226 bl.append(utils::RBD_DIFF_BANNER);
230 tag = RBD_DIFF_FROM_SNAP;
232 ::encode(f_from, bl);
236 tag = RBD_DIFF_TO_SNAP;
241 tag = RBD_DIFF_IMAGE_SIZE;
243 ::encode(s_size, bl);
247 std::cerr << "rbd: failed to write merged diff header" << std::endl;
252 pc_size = f_size << 1;
254 pc_size = s_size << 1;
257 while (!f_end || !s_end) {
258 // progress through input
259 pc.update_progress(f_off + s_off, pc_size);
261 if (!f_end && !f_len) {
262 uint64_t last_off = f_off;
264 r = parse_diff_body(fd, &f_tag, &f_off, &f_len);
265 dout(2) << "first diff data chunk: tag=" << f_tag << ", "
266 << "off=" << f_off << ", "
267 << "len=" << f_len << dendl;
269 std::cerr << "rbd: failed to read first diff data chunk header"
274 if (f_tag == RBD_DIFF_END) {
276 f_tag = RBD_DIFF_ZERO;
279 f_len = s_size - f_size;
284 if (last_off > f_off) {
286 std::cerr << "rbd: out-of-order offset from first diff ("
287 << last_off << " > " << f_off << ")" << std::endl;
292 if (!s_end && !s_len) {
293 uint64_t last_off = s_off;
295 r = parse_diff_body(sd, &s_tag, &s_off, &s_len);
296 dout(2) << "second diff data chunk: tag=" << s_tag << ", "
297 << "off=" << s_off << ", "
298 << "len=" << s_len << dendl;
300 std::cerr << "rbd: failed to read second diff data chunk header"
305 if (s_tag == RBD_DIFF_END) {
309 s_len = f_size - s_size;
314 if (last_off > s_off) {
316 std::cerr << "rbd: out-of-order offset from second diff ("
317 << last_off << " > " << s_off << ")" << std::endl;
322 if (f_off < s_off && f_len) {
323 uint64_t delta = s_off - f_off;
326 r = accept_diff_body(fd, pd, f_tag, f_off, delta);
328 std::cerr << "rbd: failed to merge diff chunk" << std::endl;
339 assert(f_off >= s_off);
341 if (f_off < s_off + s_len && f_len) {
342 uint64_t delta = s_off + s_len - f_off;
345 if (f_tag == RBD_DIFF_WRITE) {
347 bufferptr bp = buffer::create(delta);
348 r = safe_read_exact(fd, bp.c_str(), delta);
350 off64_t l = lseek64(fd, delta, SEEK_CUR);
351 r = l < 0 ? -errno : 0;
354 std::cerr << "rbd: failed to skip first diff data" << std::endl;
366 assert(f_off >= s_off + s_len);
368 r = accept_diff_body(sd, pd, s_tag, s_off, s_len);
370 std::cerr << "rbd: failed to merge diff chunk" << std::endl;
377 assert(f_end && s_end);
383 __u8 tag = RBD_DIFF_END;
407 void get_arguments(po::options_description *positional,
408 po::options_description *options) {
409 positional->add_options()
410 ("diff1-path", "path to first diff (or '-' for stdin)")
411 ("diff2-path", "path to second diff");
412 at::add_path_options(positional, options,
413 "path to merged diff (or '-' for stdout)");
414 at::add_no_progress_option(options);
417 int execute(const po::variables_map &vm) {
418 std::string first_diff = utils::get_positional_argument(vm, 0);
419 if (first_diff.empty()) {
420 std::cerr << "rbd: first diff was not specified" << std::endl;
424 std::string second_diff = utils::get_positional_argument(vm, 1);
425 if (second_diff.empty()) {
426 std::cerr << "rbd: second diff was not specified" << std::endl;
431 int r = utils::get_path(vm, utils::get_positional_argument(vm, 2),
437 r = do_merge_diff(first_diff.c_str(), second_diff.c_str(), path.c_str(),
438 vm[at::NO_PROGRESS].as<bool>());
440 cerr << "rbd: merge-diff error" << std::endl;
447 Shell::Action action(
448 {"merge-diff"}, {}, "Merge two diff exports together.", "",
449 &get_arguments, &execute);
451 } // namespace merge_diff
452 } // namespace action