Merge branch 'bug1376'

This commit is contained in:
Nick Mathewson 2013-10-11 12:51:15 -04:00
commit 0546edde66
6 changed files with 126 additions and 7 deletions

4
changes/bug1376 Normal file
View File

@ -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.

View File

@ -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);
}

View File

@ -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,

View File

@ -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);

View File

@ -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;
}

View File

@ -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),