WORM: Write Once Read Many times xlator support

This xlator will allow files to be opened for write in append mode
only. Mount with --worm(glusterfs) or -o worm (mount) option to
enable worm xlator

Change-Id: I1be02fcf2aee2182ea2c66b514357918136fabeb
BUG: 3166
Reviewed-on: http://review.gluster.com/23
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@gluster.com>

1 files changed, 101 insertions, 0 deletions

diff --git a/xlators/features/read-only/src/worm.c b/xlators/features/read-only/src/worm.c
new file mode 100644
index 00000000000..790bc3234dd
--- /dev/null
+++ b/xlators/features/read-only/src/worm.c
@@ -0,0 +1,101 @@
+/*
+  Copyright (c) 2008-2011 Gluster, Inc. <http://www.gluster.com>
+  This file is part of GlusterFS.
+
+  GlusterFS is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published
+  by the Free Software Foundation; either version 3 of the License,
+  or (at your option) any later version.
+
+  GlusterFS is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "xlator.h"
+#include "defaults.h"
+#include "read-only-common.h"
+
+static int32_t
+worm_open_cbk (call_frame_t *frame, void *cookie, xlator_t *this, int32_t op_ret,
+             int32_t op_errno, fd_t *fd)
+{
+        STACK_UNWIND_STRICT (open, frame, op_ret, op_errno, fd);
+        return 0;
+}
+
+int32_t
+worm_open (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
+         fd_t *fd, int32_t wbflags)
+{
+        if ((((flags & O_ACCMODE) == O_WRONLY) ||
+              ((flags & O_ACCMODE) == O_RDWR)) &&
+              !(flags & O_APPEND)) {
+                STACK_UNWIND_STRICT (open, frame, -1, EROFS, NULL);
+                return 0;
+        }
+
+        STACK_WIND (frame, worm_open_cbk, FIRST_CHILD(this),
+                    FIRST_CHILD(this)->fops->open, loc, flags, fd, wbflags);
+        return 0;
+}
+
+int32_t
+init (xlator_t *this)
+{
+        if (!this->children || this->children->next) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "translator not configured with exactly one child");
+                return -1;
+        }
+
+        if (!this->parents) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "dangling volume. check volfile ");
+        }
+
+        return 0;
+}
+
+
+void
+fini (xlator_t *this)
+{
+        return;
+}
+
+struct xlator_fops fops = {
+        
+        .open        = worm_open,
+
+        .unlink      = ro_unlink,
+        .rmdir       = ro_rmdir,
+        .rename      = ro_rename,
+        .truncate    = ro_truncate,
+        .removexattr = ro_removexattr,
+        .fsyncdir    = ro_fsyncdir,
+        .xattrop     = ro_xattrop,
+        .inodelk     = ro_inodelk,
+        .finodelk    = ro_finodelk,
+        .entrylk     = ro_entrylk,
+        .fentrylk    = ro_fentrylk,
+        .lk          = ro_lk,
+};
+
+struct xlator_cbks cbks = {
+};
+
+struct volume_options options[] = {
+        { .key = {NULL} },
+};
+