PR: bin/3478

    Have pwd_mkdb lock the source file while rebuilding the database.  When
    called by programs such as vipw, the source file is a temporary file and
    this does not conflict with the lock on /etc/master.passwd already held
    by vipw.  When run manually, however, master.passwd is typically specified
    as the argument and the locking prevents other programs from messing with
    master.passwd during the database rebuild.

    Also pwd_mkdb uses a blocking exclusive lock as it may be called from
    a script.  The -N option was added to cause pwd_mkdb to get the lock
    non-blocking and exit with an error if the attempt fails, again useful
    for scripts.

1 files changed, 7 insertions, 0 deletions

diff --git a/usr.sbin/pwd_mkdb/pwd_mkdb.8 b/usr.sbin/pwd_mkdb/pwd_mkdb.8
index 54abc76..7beecd7 100644
--- a/usr.sbin/pwd_mkdb/pwd_mkdb.8
+++ b/usr.sbin/pwd_mkdb/pwd_mkdb.8
@@ -40,6 +40,7 @@
 .Sh SYNOPSIS
 .Nm pwd_mkdb
 .Op Fl C
+.Op Fl N
 .Op Fl p
 .Op Fl d Ar directory
 .Op Fl s Ar cachesize
@@ -67,6 +68,12 @@ The options are as follows:
 .It Fl C
 Check if the password file is in the correct format. Do not
 change, add, or remove any files.
+.It Fl N
+Tell
+.Nm Pwd_mkdb
+to exit with an error if it cannot obtain a lock on the file.  By default,
+we block waiting for a lock on the source file.  The lock is held through
+the rebuilding of the database.
 .It Fl p
 Create a Version 7 style password file and install it into
 .Pa /etc/passwd .