journal-file: explicitly handle file systems that do not support hole punching

Apparently the error code fallocate() returns if hole punching is not
supported is not too well defined (man page just says "an error is
returned"), hence let's accept the usual set of errors, and the
normalize it to EOPNOTSUPP, and generate a clear error message in this
case.

diff --git a/src/journal/managed-journal-file.c b/src/journal/managed-journal-file.c
index 5d5ec9f9203761d978a7a81f4a4bbc05e3276909..657cf5ebbf6ee8ef4b58313bf9e1050aa5fde073 100644 (file)
--- a/src/journal/managed-journal-file.c
+++ b/src/journal/managed-journal-file.c
@@ -5,6 +5,7 @@
 
 #include "chattr-util.h"
 #include "copy.h"
+#include "errno-util.h"
 #include "fd-util.h"
 #include "format-util.h"
 #include "journal-authenticate.h"
@@ -91,8 +92,14 @@ static int managed_journal_file_entry_array_punch_hole(JournalFile *f, uint64_t
                 return 0;
         }
 
-        if (fallocate(f->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, sz) < 0)
+        if (fallocate(f->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, sz) < 0) {
+                if (ERRNO_IS_NOT_SUPPORTED(errno)) {
+                        log_debug("Hole punching not supported by backing file system, skipping.");
+                        return -EOPNOTSUPP; /* Make recognizable */
+                }
+
                 return log_debug_errno(errno, "Failed to punch hole in entry array of %s: %m", f->path);
+        }
 
         return 0;
 }
@@ -135,8 +142,12 @@ static int managed_journal_file_punch_holes(JournalFile *f) {
                                 if (le64toh(o.data.n_entries) == 0)
                                         continue;
 
-                                (void) managed_journal_file_entry_array_punch_hole(
-                                        f, le64toh(o.data.entry_array_offset), le64toh(o.data.n_entries) - 1);
+                                r = managed_journal_file_entry_array_punch_hole(
+                                                f, le64toh(o.data.entry_array_offset), le64toh(o.data.n_entries) - 1);
+                                if (r == -EOPNOTSUPP)
+                                        return -EOPNOTSUPP;
+
+                                /* Ignore other errors */
                         }
                 }
         }