lustre: add initial changelog reader (WIP)

Author: bertschinger

contrib/lustre/changelog_reader.c

@@ -0,0 +1,160 @@
+/*
+This file is part of GUFI, which is part of MarFS, which is released
+under the BSD license.
+
+
+Copyright (c) 2017, Los Alamos National Security (LANS), LLC
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+may be used to endorse or promote products derived from this software without
+specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+From Los Alamos National Security, LLC:
+LA-CC-15-039
+
+Copyright (c) 2017, Los Alamos National Security, LLC All rights reserved.
+Copyright 2017. Los Alamos National Security, LLC. This software was produced
+under U.S. Government contract DE-AC52-06NA25396 for Los Alamos National
+Laboratory (LANL), which is operated by Los Alamos National Security, LLC for
+the U.S. Department of Energy. The U.S. Government has rights to use,
+reproduce, and distribute this software.  NEITHER THE GOVERNMENT NOR LOS
+ALAMOS NATIONAL SECURITY, LLC MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR
+ASSUMES ANY LIABILITY FOR THE USE OF THIS SOFTWARE.  If software is
+modified to produce derivative works, such modified software should be
+clearly marked, so as not to confuse it with the version available from
+LANL.
+
+THIS SOFTWARE IS PROVIDED BY LOS ALAMOS NATIONAL SECURITY, LLC AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL LOS ALAMOS NATIONAL SECURITY, LLC OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+OF SUCH DAMAGE.
+*/
+
+/*
+ * To build:
+ *
+ *     export LUSTRE_LIBRARY_DIR=/home/$USER/git/lustre-release/lustre/utils/.libs
+ *     export LUSTRE_INCLUDE_DIR=/home/$USER/git/lustre-release/lustre/include/
+ *     gcc -D_GNU_SOURCE -I$LUSTRE_INCLUDE_DIR -I$LUSTRE_INCLUDE_DIR/uapi/ -L$LUSTRE_LIBRARY_DIR -llustreapi changelog_reader.c
+ *
+ * To run:
+ *
+ *     export LD_LIBRARY_PATH=$LUSTRE_LIBRARY_DIR
+ *     ./a.out
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "lustre/lustreapi.h"
+
+/** returns fid object sequence */
+static inline __u64 fid_seq(const struct lu_fid *fid)
+{
+	return fid->f_seq;
+}
+
+/** returns fid object id */
+static inline __u32 fid_oid(const struct lu_fid *fid)
+{
+	return fid->f_oid;
+}
+
+/**
+ * Flatten 128-bit FID values into a 64-bit value for use as an inode number.
+ *
+ * This is taken from lustre/include/uapi/linux/lustre/lustre_fid.h, with
+ * irrelevant parts (i.e., IGIF FIDs) removed.
+ *
+ * It would be better to directly include that header, but it's not part of the
+ * public Lustre API, and is also not designed for inclusion in userspace programs
+ * (e.g., it includes kernel headers which cannot be transitively included in
+ * userspace programs).
+ *
+ * So for lack of a better option, I copy the definition.
+ */
+static inline __u64 fid_flatten64(const struct lu_fid *fid)
+{
+	__u64 ino;
+	__u64 seq;
+
+	seq = fid_seq(fid);
+
+	ino = (seq << 24) + ((seq >> 24) & 0xffffff0000ULL) + fid_oid(fid);
+
+	return ino ?: fid_oid(fid);
+}
+
+int main(int argc, char *argv[])
+{
+    void *changelog_priv;
+    long long startrec = 0;
+    struct changelog_rec *rec;
+    int rc;
+
+    char *mdd = "lustre-MDT0000"; // TODO: make this a CLI arg
+
+	rc = llapi_changelog_start(&changelog_priv,
+				   CHANGELOG_FLAG_JOBID |
+				   CHANGELOG_FLAG_EXTRA_FLAGS,
+				   mdd, startrec);
+    if (rc < 0) {
+        fprintf(stderr, "error starting changelog: %s\n", strerror(-rc));
+        return EXIT_FAILURE;
+    }
+
+    while ((rc = llapi_changelog_recv(changelog_priv, &rec)) == 0) {
+        /*
+        printf("record: %s, fid: "DFID", parent: "DFID,
+                changelog_type2str(rec->cr_type),
+                PFID(&rec->cr_tfid),
+                PFID(&rec->cr_pfid));
+        printf(" inode: ");
+        */
+
+        printf("%llu\n", fid_flatten64(&rec->cr_pfid));
+    }
+
+    llapi_changelog_fini(&changelog_priv);
+
+    return rc == 1 ? EXIT_SUCCESS : EXIT_FAILURE;
+}