return 0;
}
-static uint64_t journal_file_entry_seqnum(JournalFile *f, uint64_t *seqnum) {
- uint64_t r;
+static uint64_t journal_file_entry_seqnum(
+ JournalFile *f,
+ uint64_t *seqnum) {
+
+ uint64_t ret;
assert(f);
assert(f->header);
- r = le64toh(f->header->tail_entry_seqnum) + 1;
+ /* Picks a new sequence number for the entry we are about to add and returns it. */
+
+ ret = le64toh(f->header->tail_entry_seqnum) + 1;
if (seqnum) {
- /* If an external seqnum counter was passed, we update
- * both the local and the external one, and set it to
- * the maximum of both */
+ /* If an external seqnum counter was passed, we update both the local and the external one,
+ * and set it to the maximum of both */
- if (*seqnum + 1 > r)
- r = *seqnum + 1;
+ if (*seqnum + 1 > ret)
+ ret = *seqnum + 1;
- *seqnum = r;
+ *seqnum = ret;
}
- f->header->tail_entry_seqnum = htole64(r);
+ f->header->tail_entry_seqnum = htole64(ret);
if (f->header->head_entry_seqnum == 0)
- f->header->head_entry_seqnum = htole64(r);
+ f->header->head_entry_seqnum = htole64(ret);
- return r;
+ return ret;
+}
+
+static void journal_file_revert_entry_seqnum(
+ JournalFile *f,
+ uint64_t *seqnum,
+ uint64_t revert_seqnum) {
+
+ assert(f);
+ assert(f->header);
+
+ if (revert_seqnum == 0) /* sequence number 0? can't go back */
+ return;
+
+ /* Undoes the effect of journal_file_entry_seqnum() above: if we fail to append an entry to a file,
+ * let's revert the seqnum we were about to use, so that we can use it on the next entry. */
+
+ if (le64toh(f->header->tail_entry_seqnum) == revert_seqnum)
+ f->header->tail_entry_seqnum = htole64(revert_seqnum - 1);
+
+ if (le64toh(f->header->head_entry_seqnum) == revert_seqnum)
+ f->header->head_entry_seqnum = 0;
+
+ if (seqnum && *seqnum == revert_seqnum)
+ *seqnum = revert_seqnum - 1;
}
int journal_file_append_object(
#if HAVE_GCRYPT
r = journal_file_hmac_put_object(f, OBJECT_ENTRY, o, np);
if (r < 0)
- return r;
+ goto fail;
#endif
r = journal_file_link_entry(f, o, np);
if (r < 0)
- return r;
+ goto fail;
if (ret)
*ret = o;
*ret_offset = np;
return 0;
+
+fail:
+ journal_file_revert_entry_seqnum(f, seqnum, le64toh(o->entry.seqnum));
+ return r;
}
void journal_file_post_change(JournalFile *f) {