journal: refuse opening journal files from the future for writing

Never permit that we write to journal files that have newer timestamps than our
local wallclock has. If we'd accept that, then the entries in the file might
end up not being ordered strictly.

Let's refuse this with ETXTBSY, and then immediately rotate to use a new file,
so that each file remains strictly ordered also be wallclock internally.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index 28aea35d18..3224bdbf5f 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -595,32 +595,44 @@ static void server_cache_hostname(Server *s) {
 
 static bool shall_try_append_again(JournalFile *f, int r) {
         switch(r) {
+
         case -E2BIG:           /* Hit configured limit          */
         case -EFBIG:           /* Hit fs limit                  */
         case -EDQUOT:          /* Quota limit hit               */
         case -ENOSPC:          /* Disk full                     */
                 log_debug("%s: Allocation limit reached, rotating.", f->path);
                 return true;
+
         case -EIO:             /* I/O error of some kind (mmap) */
                 log_warning("%s: IO error, rotating.", f->path);
                 return true;
+
         case -EHOSTDOWN:       /* Other machine                 */
                 log_info("%s: Journal file from other machine, rotating.", f->path);
                 return true;
+
         case -EBUSY:           /* Unclean shutdown              */
                 log_info("%s: Unclean shutdown, rotating.", f->path);
                 return true;
+
         case -EPROTONOSUPPORT: /* Unsupported feature           */
                 log_info("%s: Unsupported feature, rotating.", f->path);
                 return true;
+
         case -EBADMSG:         /* Corrupted                     */
         case -ENODATA:         /* Truncated                     */
         case -ESHUTDOWN:       /* Already archived              */
                 log_warning("%s: Journal file corrupted, rotating.", f->path);
                 return true;
+
         case -EIDRM:           /* Journal file has been deleted */
                 log_warning("%s: Journal file has been deleted, rotating.", f->path);
                 return true;
+
+        case -ETXTBSY:         /* Journal file is from the future */
+                log_warning("%s: Journal file is from the future, rotateing.", f->path);
+                return true;
+
         default:
                 return false;
         }