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feat(basis): rsync quick-check default + FastSync-only --verify-basis

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- default basis match is rsync's metadata quick-check (size + mtime; size-only
  drops mtime; -I disables), no mandatory content digest
- new long-only --verify-basis (wire bool, protocol stays 2.28.0) restores the
  strict whole-file content equality
- --copy-dest re-applies source attributes; basis-hit 256 MiB cap removed by
  streaming the copy/hash; basis miss keeps the normal payload bound
- compare/copy/link-dest rows -> caveat; tally 116/13/28
This commit is contained in:
TapTap
2026-09-19 15:55:51 +02:00
parent 8ec8cb7203
commit 67076bf218
23 changed files with 940 additions and 255 deletions
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src/client/client_cli.c
+6
View File
@@ -1054,6 +1054,11 @@ static const OptionEntry OPTION_TABLE[] = {
* --remote-option is parsed. --trust-sender is a local receiver policy and
* never travels to the remote peer. */
{"--trust-sender", NULL, OPT_FLAG, offsetof(Config, trust_sender)},
/* FastSync-only (not an rsync option): require a basis-hit's content to
* match the source by whole-file digest instead of trusting rsync's
* size+mtime quick-check. Long-only; crosses the wire so the receiver
* performs the extra read/hash. */
{"--verify-basis", NULL, OPT_FLAG, offsetof(Config, verify_basis)},
};
/* Only boolean options with no required argument are safe to negate. */
@@ -1096,6 +1101,7 @@ static const NegatableOption NEGATABLE_OPTIONS[] = {
{"xattrs", "X", offsetof(Config, preserve_xattrs)},
{"acls", "A", offsetof(Config, preserve_acls)},
{"fake-super", NULL, offsetof(Config, fake_super)},
{"verify-basis", NULL, offsetof(Config, verify_basis)},
};
static bool opt_is(const char* arg, const char* name, const char* alias) {
src/client/client_send.c
+16 -68
View File
@@ -1047,53 +1047,6 @@ static bool files_from_list_check(const Config* config, ArrayList* missing_dest,
return true;
}
/* Basis directories are honored by the receiver's per-file incremental check,
which (like every whole-file payload path in FastSync) is bounded by
MAX_RECEIVE_WHOLE_FILE_SIZE. rsync would apply basis dirs to files of any
size; FastSync cannot, so when basis dirs are requested this preflight scan
refuses the run up front with a clear diagnostic instead of letting the
receiver abort the whole transfer mid-stream with no client explanation.
Returns true when the tree can be transferred. */
static bool basis_oversize_preflight(const Config* config) {
PreparedScanner prepared;
if (!prepare_scanner(config, 0, &prepared))
return false;
DirectoryScanner* scanner =
directory_scanner_create_with_options(config->send_directory, &prepared.options);
if (!scanner) {
prepared_scanner_destroy(&prepared);
return false;
}
bool ok = true;
Chunk* chunk;
while ((chunk = directory_scanner_next(scanner)) != NULL) {
for (int i = 0; i < chunk->element_count; i++) {
File* f = chunk->items[i];
if (f == NULL || f->is_dir || f->data == NULL || f->data->size <= MAX_RECEIVE_WHOLE_FILE_SIZE)
continue;
char* escaped = output_escape(file_wire_path(f), config->eight_bit_output);
log_message(LOG_LEVEL_ERROR,
"%s is %llu bytes, larger than the %llu-byte whole-file transfer limit; "
"--compare-dest/--copy-dest/--link-dest cannot sync files above this limit",
escaped ? escaped : "<allocation failed>", (unsigned long long)f->data->size,
(unsigned long long)MAX_RECEIVE_WHOLE_FILE_SIZE);
free(escaped);
ok = false;
break;
}
chunk_destroy(chunk);
if (!ok)
break;
}
if (directory_scanner_failed(scanner) || directory_scanner_had_io_error(scanner))
ok = false;
/* The scanner borrows prepared.options' base_filters/hardlinks pointers, so
prepared must outlive the scanner. */
directory_scanner_destroy(scanner);
prepared_scanner_destroy(&prepared);
return ok;
}
/* Read the daemon's MOTD frame and, unless --no-motd, display it on stdout.
*
* The daemon sends the MOTD as the first thing after the config-frame STATUS_OK
@@ -1939,11 +1892,13 @@ static int incremental_check(Client* client, File* file, const Config* config,
return -1;
if (!send_n_data(client->file_descriptor, &mtime_nsec, sizeof(mtime_nsec)))
return -1;
/* With alternate basis directories the receiver must be able to verify the
* content of every candidate basis file, so the sender supplies its whole-file
* digest (computed with the negotiated --checksum-choice algorithm and
* --checksum-seed) for every file even when --checksum was not requested. */
if (config->checksum || config_has_basis(config)) {
/* The whole-file digest (negotiated --checksum-choice algorithm and
* --checksum-seed) is only needed when it drives a decision: --checksum's
* per-file quick check, or a --verify-basis content equality. Under the
* default metadata quick-check the receiver never reads it, so the sender
* skips the full-file read/hash exactly as rsync does for a plain
* --link-dest run. */
if (config->checksum || config->verify_basis) {
uint8_t digest[CHECKSUM_MAX_DIGEST_LEN];
size_t digest_len = 0;
if (!file_checksum(file, (ChecksumAlgo)config->checksum_algo, config->checksum_seed, digest,
@@ -1954,6 +1909,15 @@ static int incremental_check(Client* client, File* file, const Config* config,
!send_n_data(client->file_descriptor, digest, wire_len))
return -1;
}
/* Basis directories: the receiver materializes a hit from the basis without a
* data frame, so it would otherwise only have the basis inode's metadata.
* Transmit the SOURCE metadata with the check (rsync's copy-then-fix) so a
* --copy-dest hit / --link-dest copy fallback applies the source's
* attributes. Symmetric with incremental_check_receive_request. */
if (config_has_basis(config) && config->use_metadata) {
if (!metadata_send(client->file_descriptor, file->metadata))
return -1;
}
Status s;
if (!receive_status(client->file_descriptor, &s))
return -1;
@@ -2193,12 +2157,6 @@ static int send_dry_run_remote(Config* config) {
}
if (missing_args)
array_list_delete(missing_args);
/* Alternate basis dirs force the whole-file per-file check on the real
receiver; refuse an oversize source up front exactly as send_files does so
dry-run reports the same clear diagnostic instead of aborting mid-stream. */
if (config_has_basis(config) && !basis_oversize_preflight(config))
return 1;
/* A live session may follow, so arm graceful abort handling. */
client_set_abort_armed(true);
Client* client = connect_transfer_client(config);
@@ -3240,11 +3198,6 @@ int send_files(Config* config) {
array_list_delete(missing_args);
return 1;
}
if (config_has_basis(config) && !basis_oversize_preflight(config)) {
if (missing_args)
array_list_delete(missing_args);
return 1;
}
/* From here on a server session may be live, so Ctrl-C/SIGTERM should set the
abort flag (and be forwarded as STATUS_ABORT) instead of terminating. */
@@ -3682,11 +3635,6 @@ int send_files_multithreaded(Config** config_ptr) {
array_list_delete(missing_args);
return 1;
}
if (config_has_basis(config) && !basis_oversize_preflight(config)) {
if (missing_args)
array_list_delete(missing_args);
return 1;
}
/* Armed only once a session may go live (see send_files). */
client_set_abort_armed(true);
src/client/usage.c
+3
View File
@@ -138,6 +138,9 @@ void print_usage(void) {
printf(" into the destination instead of transferring its data\n");
printf(" --link-dest <dir> Like --copy-dest, but hard-links the unchanged file from DIR\n");
printf(" into the destination (repeatable; earlier DIRs win)\n");
printf(" --verify-basis FastSync-only: require a basis hit's content to match the\n");
printf(" source by whole-file digest instead of trusting rsync's\n");
printf(" size+mtime (or --size-only) quick-check\n");
printf(" --checksum-choice, --cc <alg> Whole-file checksum algorithm for --incremental/\n");
printf(" --checksum compares. Accepted: xxh128 (default), xxh3, xxh64\n");
printf(" (aka xxhash), md5, md4, sha1, or none. A two-name\n");