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authorFlorian Weimer <fweimer@redhat.com>2018-02-21 10:42:48 +0100
committerFlorian Weimer <fweimer@redhat.com>2018-02-21 10:42:48 +0100
commit999a6dab3ee1c8e77bb348ba2389e7aeb5c062b2 (patch)
treeb88f28c02d2f98d8576f021b8d441814d848133b /elf/cache.c
parent52a01100ad011293197637e42b5be1a479a2f4ae (diff)
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ldconfig: Sync temporary files to disk before renaming them [BZ #20890]
If the system crashes before the file data has been written to disk, the
file system recovery upon the next mount may restore a partially
rewritten temporary file under the non-temporary (final) name (after the
rename operation).
Diffstat (limited to 'elf/cache.c')
-rw-r--r--elf/cache.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/elf/cache.c b/elf/cache.c
index c2c010f97b..e63979da7d 100644
--- a/elf/cache.c
+++ b/elf/cache.c
@@ -454,8 +454,7 @@ save_cache (const char *cache_name)
 	error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
     }
 
-  if (write (fd, strings, total_strlen) != (ssize_t) total_strlen
-      || close (fd))
+  if (write (fd, strings, total_strlen) != (ssize_t) total_strlen)
     error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 
   /* Make sure user can always read cache file */
@@ -464,6 +463,10 @@ save_cache (const char *cache_name)
 	   _("Changing access rights of %s to %#o failed"), temp_name,
 	   S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 
+  /* Make sure that data is written to disk.  */
+  if (fsync (fd) != 0 || close (fd) != 0)
+    error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
+
   /* Move temporary to its final location.  */
   if (rename (temp_name, cache_name))
     error (EXIT_FAILURE, errno, _("Renaming of %s to %s failed"), temp_name,
@@ -818,7 +821,8 @@ save_aux_cache (const char *aux_cache_name)
 
   if (write (fd, file_entries, file_entries_size + total_strlen)
       != (ssize_t) (file_entries_size + total_strlen)
-      || close (fd))
+      || fdatasync (fd) != 0
+      || close (fd) != 0)
     {
       unlink (temp_name);
       goto out_fail;