Imported Upstream version 2.6.0

[debian/amanda] / common-src / amflock-lockf.c

diff --git a/common-src/amflock-lockf.c b/common-src/amflock-lockf.c
new file mode 100644 (file)
index 0000000..90af1ff
--- /dev/null
+++ b/common-src/amflock-lockf.c
@@ -0,0 +1,76 @@
+/*
+ * Amanda, The Advanced Maryland Automatic Network Disk Archiver
+ * Copyright (c) 1991-1998 University of Maryland at College Park
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of U.M. not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  U.M. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ *
+ * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
+ * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Authors: the Amanda Development Team.  Its members are listed in a
+ * file named AUTHORS, in the root directory of this distribution.
+ */
+
+/* moved from amflock.c by Dustin J. Mitchell <dustin@zmanda.com> */
+
+#include "amanda.h"
+
+/* XPG4-UNIX (eg, SGI IRIX, DEC DU) has F_ULOCK instead of F_UNLOCK */
+#if defined(F_ULOCK) && !defined(F_UNLOCK)
+#  define F_UNLOCK F_ULOCK
+#endif
+
+static int
+lockf_lock(
+    int        fd,
+    G_GNUC_UNUSED char *resource)
+{
+    return lockf(fd, F_LOCK, (off_t)0);
+}
+
+static int
+lockf_unlock(
+    int        fd,
+    G_GNUC_UNUSED char *resource)
+{
+    off_t pos;
+
+    /* unlock from here on */
+    if (lockf(fd, F_UNLOCK, (off_t)0) == -1) return -1;
+
+    /* unlock from bof to here */
+    pos = lseek(fd, (off_t)0, SEEK_CUR);
+    if (pos == (off_t)-1) {
+       if (errno == ESPIPE) 
+           pos = (off_t)0;
+       else
+           return -1;
+    }
+
+    if (pos > (off_t)0) {
+       if (lockf(fd, F_UNLOCK, -pos) == -1)
+           return -1;
+    }
+
+    return 0;
+}
+
+amflock_impl_t amflock_lockf_impl = {
+    lockf_lock,
+    lockf_lock, /* no read-only support */
+    lockf_unlock,
+    "lockf"
+};