diff options
| -rw-r--r-- | changes/bug1376 | 4 | ||||
| -rw-r--r-- | src/common/util.c | 14 | ||||
| -rw-r--r-- | src/common/util.h | 2 | ||||
| -rw-r--r-- | src/or/dirvote.c | 2 | ||||
| -rw-r--r-- | src/or/routerlist.c | 4 | ||||
| -rw-r--r-- | src/test/test_util.c | 107 |
6 files changed, 126 insertions, 7 deletions
diff --git a/changes/bug1376 b/changes/bug1376 new file mode 100644 index 0000000000..bee42a39a4 --- /dev/null +++ b/changes/bug1376 @@ -0,0 +1,4 @@ + o Minor bugfixes: + + - Added additional argument to write_chunks_to_file to optionally skip + using a temp file to do non-atomic writes. Implements ticket #1376. diff --git a/src/common/util.c b/src/common/util.c index a4cdae04ee..f3a6c10621 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -2191,12 +2191,20 @@ write_chunks_to_file_impl(const char *fname, const smartlist_t *chunks, return -1; } -/** Given a smartlist of sized_chunk_t, write them atomically to a file - * <b>fname</b>, overwriting or creating the file as necessary. */ +/** Given a smartlist of sized_chunk_t, write them to a file + * <b>fname</b>, overwriting or creating the file as necessary. + * If <b>no_tempfile</b> is 0 then the file will be written + * atomically. */ int -write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin) +write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin, + int no_tempfile) { int flags = OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT); + + if (no_tempfile) { + /* O_APPEND stops write_chunks_to_file from using tempfiles */ + flags |= O_APPEND; + } return write_chunks_to_file_impl(fname, chunks, flags); } diff --git a/src/common/util.h b/src/common/util.h index fdd8c135a9..dcf45942f0 100644 --- a/src/common/util.h +++ b/src/common/util.h @@ -365,7 +365,7 @@ typedef struct sized_chunk_t { size_t len; } sized_chunk_t; int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks, - int bin); + int bin, int no_tempfile); int append_bytes_to_file(const char *fname, const char *str, size_t len, int bin); int write_bytes_to_new_file(const char *fname, const char *str, size_t len, diff --git a/src/or/dirvote.c b/src/or/dirvote.c index 12ceba8549..456a033ec9 100644 --- a/src/or/dirvote.c +++ b/src/or/dirvote.c @@ -3143,7 +3143,7 @@ dirvote_compute_consensuses(void) }); votefile = get_datadir_fname("v3-status-votes"); - write_chunks_to_file(votefile, votestrings, 0); + write_chunks_to_file(votefile, votestrings, 0, 0); tor_free(votefile); SMARTLIST_FOREACH(votestrings, sized_chunk_t *, c, tor_free(c)); smartlist_free(votestrings); diff --git a/src/or/routerlist.c b/src/or/routerlist.c index cf9cf87a27..c0c4d9a4c0 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -449,7 +449,7 @@ trusted_dirs_flush_certs_to_disk(void) } DIGESTMAP_FOREACH_END; filename = get_datadir_fname("cached-certs"); - if (write_chunks_to_file(filename, chunks, 0)) { + if (write_chunks_to_file(filename, chunks, 0, 0)) { log_warn(LD_FS, "Error writing certificates to disk."); } tor_free(filename); @@ -1069,7 +1069,7 @@ router_rebuild_store(int flags, desc_store_t *store) smartlist_add(chunk_list, c); } SMARTLIST_FOREACH_END(sd); - if (write_chunks_to_file(fname_tmp, chunk_list, 1)<0) { + if (write_chunks_to_file(fname_tmp, chunk_list, 1, 1)<0) { log_warn(LD_FS, "Error writing router store to disk."); goto done; } diff --git a/src/test/test_util.c b/src/test/test_util.c index 1f3b4d6dec..ba58b31d4b 100644 --- a/src/test/test_util.c +++ b/src/test/test_util.c @@ -102,6 +102,112 @@ test_util_read_file_eof_zero_bytes(void *arg) test_util_read_until_eof_impl("tor_test_fifo_empty", 0, 10000); } +/* Test the basic expected behaviour for write_chunks_to_file. + * NOTE: This will need to be updated if we ever change the tempfile location + * or extension */ +static void +test_util_write_chunks_to_file(void *arg) +{ + char *fname = NULL; + char *tempname = NULL; + char *str = NULL; + int r; + int fd = -1; + struct stat st; + + /* These should be two different sizes to ensure the data is different + * between the data file and the temp file's 'known string' */ + int temp_str_len = 1024; + int data_str_len = 512; + char *data_str = tor_malloc(data_str_len); + char *temp_str = tor_malloc(temp_str_len); + + smartlist_t *chunks = smartlist_new(); + sized_chunk_t c = {data_str, data_str_len/2}; + sized_chunk_t c2 = {data_str + data_str_len/2, data_str_len/2}; + (void)arg; + + crypto_rand(temp_str, temp_str_len); + crypto_rand(data_str, data_str_len); + + // Ensure it can write multiple chunks + + smartlist_add(chunks, &c); + smartlist_add(chunks, &c2); + + /* + * Check if it writes using a tempfile + */ + fname = tor_strdup(get_fname("write_chunks_with_tempfile")); + tor_asprintf(&tempname, "%s.tmp", fname); + + // write a known string to a file where the tempfile will be + r = write_bytes_to_file(tempname, temp_str, temp_str_len, 1); + tt_int_op(r, ==, 0); + + // call write_chunks_to_file + r = write_chunks_to_file(fname, chunks, 1, 0); + tt_int_op(r, ==, 0); + + // assert the file has been written (expected size) + str = read_file_to_str(fname, RFTS_BIN, &st); + tt_assert(str != NULL); + tt_int_op(st.st_size, ==, data_str_len); + test_mem_op(data_str, ==, str, data_str_len); + tor_free(str); + close(fd); + + // assert that the tempfile is removed (should not leave artifacts) + str = read_file_to_str(tempname, RFTS_BIN|RFTS_IGNORE_MISSING, &st); + tt_assert(str == NULL); + + // Remove old testfile for second test + r = unlink(fname); + tt_int_op(r, ==, 0); + tor_free(fname); + tor_free(tempname); + + /* + * Check if it skips using a tempfile with flags + */ + fname = tor_strdup(get_fname("write_chunks_with_no_tempfile")); + tor_asprintf(&tempname, "%s.tmp", fname); + + // write a known string to a file where the tempfile will be + r = write_bytes_to_file(tempname, temp_str, temp_str_len, 1); + tt_int_op(r, ==, 0); + + // call write_chunks_to_file with no_tempfile = true + r = write_chunks_to_file(fname, chunks, 1, 1); + tt_int_op(r, ==, 0); + + // assert the file has been written (expected size) + str = read_file_to_str(fname, RFTS_BIN, &st); + tt_assert(str != NULL); + tt_int_op(st.st_size, ==, data_str_len); + test_mem_op(data_str, ==, str, data_str_len); + tor_free(str); + close(fd); + + // assert the tempfile still contains the known string + str = read_file_to_str(tempname, RFTS_BIN, &st); + tt_assert(str != NULL); + tt_int_op(st.st_size, ==, temp_str_len); + test_mem_op(temp_str, ==, str, temp_str_len); + + done: + unlink(fname); + unlink(tempname); + smartlist_free(chunks); + tor_free(fname); + tor_free(tempname); + tor_free(str); + tor_free(data_str); + tor_free(temp_str); + if (fd >= 0) + close(fd); +} + static void test_util_time(void) { @@ -3503,6 +3609,7 @@ struct testcase_t util_tests[] = { UTIL_TEST(read_file_eof_tiny_limit, 0), UTIL_TEST(read_file_eof_two_loops, 0), UTIL_TEST(read_file_eof_zero_bytes, 0), + UTIL_TEST(write_chunks_to_file, 0), UTIL_TEST(mathlog, 0), UTIL_TEST(weak_random, 0), UTIL_TEST(socket, TT_FORK), |