iostream-temp: If write() to temp file fails at any time, move it back to memory.

Similarly to if the write() to temp fails during the initial move attempt.
This way even if write() fails due to out of disk space, it's not visible
to caller. An error message is logged in any case.

diff --git a/src/lib/iostream-temp.c b/src/lib/iostream-temp.c
index 1b3583d5c037f0f37540d149b54c43188e70943e..bbdc764948db73f38a7ba3dfd657ab8d78792bb3 100644 (file)
--- a/src/lib/iostream-temp.c
+++ b/src/lib/iostream-temp.c
@@ -79,6 +79,36 @@ static int o_stream_temp_move_to_fd(struct temp_ostream *tstream)
        return 0;
 }
 
+int o_stream_temp_move_to_memory(struct ostream *output)
+{
+       struct temp_ostream *tstream =
+               (struct temp_ostream *)output->real_stream;
+       unsigned char buf[IO_BLOCK_SIZE];
+       uoff_t offset = 0;
+       ssize_t ret = 0;
+
+       i_assert(tstream->buf == NULL);
+       tstream->buf = buffer_create_dynamic(default_pool, 8192);
+       while (offset < tstream->ostream.ostream.offset &&
+              (ret = pread(tstream->fd, buf, sizeof(buf), offset)) > 0) {
+               if ((size_t)ret > tstream->ostream.ostream.offset - offset)
+                       ret = tstream->ostream.ostream.offset - offset;
+               buffer_append(tstream->buf, buf, ret);
+               offset += ret;
+       }
+       if (ret < 0) {
+               /* not really expecting this to happen */
+               i_error("iostream-temp %s: read(%s*) failed: %m",
+                       o_stream_get_name(&tstream->ostream.ostream),
+                       tstream->temp_path_prefix);
+               tstream->ostream.ostream.stream_errno = EIO;
+               return -1;
+       }
+       i_close_fd(&tstream->fd);
+       tstream->ostream.fd = -1;
+       return 0;
+}
+
 static ssize_t
 o_stream_temp_fd_sendv(struct temp_ostream *tstream,
                       const struct const_iovec *iov, unsigned int iov_count)
@@ -88,8 +118,18 @@ o_stream_temp_fd_sendv(struct temp_ostream *tstream,
 
        for (i = 0; i < iov_count; i++) {
                if (write_full(tstream->fd, iov[i].iov_base, iov[i].iov_len) < 0) {
-                       tstream->ostream.ostream.stream_errno = errno;
-                       return -1;
+                       i_error("iostream-temp %s: write(%s*) failed: %m - moving to memory",
+                               o_stream_get_name(&tstream->ostream.ostream),
+                               tstream->temp_path_prefix);
+                       if (o_stream_temp_move_to_memory(&tstream->ostream.ostream) < 0)
+                               return -1;
+                       for (; i < iov_count; i++) {
+                               buffer_append(tstream->buf, iov[i].iov_base, iov[i].iov_len);
+                               bytes += iov[i].iov_len;
+                               tstream->ostream.ostream.offset += iov[i].iov_len;
+                       }
+                       i_assert(tstream->fd_tried);
+                       return bytes;
                }
                bytes += iov[i].iov_len;
                tstream->ostream.ostream.offset += iov[i].iov_len;

diff --git a/src/lib/iostream-temp.h b/src/lib/iostream-temp.h
index 8f16ff0e56ae544201d0824d72db2db6d4ee4c96..bf5a45d15d29958243e44409d057dc29ac8ba1d4 100644 (file)
--- a/src/lib/iostream-temp.h
+++ b/src/lib/iostream-temp.h
@@ -25,4 +25,7 @@ struct ostream *iostream_temp_create_sized(const char *temp_path_prefix,
 struct istream *iostream_temp_finish(struct ostream **output,
                                     size_t max_buffer_size);
 
+/* For internal testing: */
+int o_stream_temp_move_to_memory(struct ostream *output);
+
 #endif

diff --git a/src/lib/test-iostream-temp.c b/src/lib/test-iostream-temp.c
index 46b5e723bc0a435de03f8d357ae609e0df3df855..f1e0496493b5265154a2e8ab5049a97e08a9df57 100644 (file)
--- a/src/lib/test-iostream-temp.c
+++ b/src/lib/test-iostream-temp.c
@@ -48,6 +48,31 @@ static void test_iostream_temp_create_sized_disk(void)
        test_end();
 }
 
+static void test_iostream_temp_create_write_error(void)
+{
+       struct ostream *output;
+
+       test_begin("iostream_temp_create_sized() write error");
+       output = iostream_temp_create_sized(".", 0, "test", 1);
+
+       test_assert(o_stream_send(output, "123", 3) == 3);
+       test_assert(o_stream_get_fd(output) != -1);
+       test_assert(output->offset == 3);
+       test_assert(o_stream_temp_move_to_memory(output) == 0);
+       test_assert(o_stream_get_fd(output) == -1);
+       test_assert(o_stream_send(output, "45", 2) == 2);
+       test_assert(output->offset == 5);
+
+       const unsigned char *data;
+       size_t size;
+       struct istream *input = iostream_temp_finish(&output, 128);
+       test_assert(i_stream_read_bytes(input, &data, &size, 5) == 1 &&
+                   memcmp(data, "12345", 5) == 0);
+       i_stream_destroy(&input);
+
+       test_end();
+}
+
 static void test_iostream_temp_istream(void)
 {
        struct istream *input, *input2, *temp_input;
@@ -120,5 +145,6 @@ void test_iostream_temp(void)
 {
        test_iostream_temp_create_sized_memory();
        test_iostream_temp_create_sized_disk();
+       test_iostream_temp_create_write_error();
        test_iostream_temp_istream();
 }