From 0c2f52bb9b0bce392f14a38d6477e396d6fc987e Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 24 Jul 2015 02:00:43 +0200
Subject: [PATCH] journal: when verifying journal files, handle empty ones
 nicely

A journal file that carries no objects should be considered valid.

Cherry-picked from: 8dc37a85255f68d62f7af66696cbf6a66401fb2a
Resolves: #1350232
---
 src/journal/journal-verify.c | 37 ++++++++++++++-----------------------
 1 file changed, 14 insertions(+), 23 deletions(-)

diff --git a/src/journal/journal-verify.c b/src/journal/journal-verify.c
index d2d5c400c..53f0550da 100644
--- a/src/journal/journal-verify.c
+++ b/src/journal/journal-verify.c
@@ -885,7 +885,11 @@ int journal_file_verify(
          * superficial structure, headers, hashes. */
 
         p = le64toh(f->header->header_size);
-        while (p != 0) {
+        for (;;) {
+                /* Early exit if there are no objects in the file, at all */
+                if (le64toh(f->header->tail_object_offset) == 0)
+                        break;
+
                 if (show_progress)
                         draw_progress(scale_progress(0x7FFF, p, le64toh(f->header->tail_object_offset)), &last_usec);
 
@@ -901,9 +905,6 @@ int journal_file_verify(
                         goto fail;
                 }
 
-                if (p == le64toh(f->header->tail_object_offset))
-                        found_last = true;
-
                 n_objects ++;
 
                 r = journal_file_object_verify(f, p, o);
@@ -1148,13 +1149,15 @@ int journal_file_verify(
                         n_weird ++;
                 }
 
-                if (p == le64toh(f->header->tail_object_offset))
-                        p = 0;
-                else
-                        p = p + ALIGN64(le64toh(o->object.size));
-        }
+                if (p == le64toh(f->header->tail_object_offset)) {
+                        found_last = true;
+                        break;
+                }
 
-        if (!found_last) {
+                p = p + ALIGN64(le64toh(o->object.size));
+        };
+
+        if (!found_last && le64toh(f->header->tail_object_offset) != 0) {
                 error(le64toh(f->header->tail_object_offset), "tail object pointer dead");
                 r = -EBADMSG;
                 goto fail;
@@ -1200,19 +1203,7 @@ int journal_file_verify(
                 goto fail;
         }
 
-        if (n_data_hash_tables != 1) {
-                error(0, "missing data hash table");
-                r = -EBADMSG;
-                goto fail;
-        }
-
-        if (n_field_hash_tables != 1) {
-                error(0, "missing field hash table");
-                r = -EBADMSG;
-                goto fail;
-        }
-
-        if (!found_main_entry_array) {
+        if (!found_main_entry_array && le64toh(f->header->entry_array_offset) != 0) {
                 error(0, "missing entry array");
                 r = -EBADMSG;
                 goto fail;