[PATCH] v9fs: VFS file, dentry, and directory operations
This part of the patch contains the VFS file, dentry & directory interfaces.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
new file mode 100644
index 0000000..306c967
--- /dev/null
+++ b/fs/9p/vfs_dentry.c
@@ -0,0 +1,126 @@
+/*
+ * linux/fs/9p/vfs_dentry.c
+ *
+ * This file contians vfs dentry ops for the 9P2000 protocol.
+ *
+ * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, write to:
+ * Free Software Foundation
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA 02111-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/inet.h>
+#include <linux/namei.h>
+#include <linux/idr.h>
+
+#include "debug.h"
+#include "v9fs.h"
+#include "9p.h"
+#include "v9fs_vfs.h"
+#include "conv.h"
+#include "fid.h"
+
+/**
+ * v9fs_dentry_validate - VFS dcache hook to validate cache
+ * @dentry: dentry that is being validated
+ * @nd: path data
+ *
+ * dcache really shouldn't be used for 9P2000 as at all due to
+ * potential attached semantics to directory traversal (walk).
+ *
+ * FUTURE: look into how to use dcache to allow multi-stage
+ * walks in Plan 9 & potential for better dcache operation which
+ * would remain valid for Plan 9 semantics. Older versions
+ * had validation via stat for those interested. However, since
+ * stat has the same approximate overhead as walk there really
+ * is no difference. The only improvement would be from a
+ * time-decay cache like NFS has and that undermines the
+ * synchronous nature of 9P2000.
+ *
+ */
+
+static int v9fs_dentry_validate(struct dentry *dentry, struct nameidata *nd)
+{
+ struct dentry *dc = current->fs->pwd;
+
+ dprintk(DEBUG_VFS, "dentry: %s (%p)\n", dentry->d_iname, dentry);
+ if (v9fs_fid_lookup(dentry, FID_OP)) {
+ dprintk(DEBUG_VFS, "VALID\n");
+ return 1;
+ }
+
+ while (dc != NULL) {
+ if (dc == dentry) {
+ dprintk(DEBUG_VFS, "VALID\n");
+ return 1;
+ }
+ if (dc == dc->d_parent)
+ break;
+
+ dc = dc->d_parent;
+ }
+
+ dprintk(DEBUG_VFS, "INVALID\n");
+ return 0;
+}
+
+/**
+ * v9fs_dentry_release - called when dentry is going to be freed
+ * @dentry: dentry that is being release
+ *
+ */
+
+void v9fs_dentry_release(struct dentry *dentry)
+{
+ dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
+
+ if (dentry->d_fsdata != NULL) {
+ struct list_head *fid_list = dentry->d_fsdata;
+ struct v9fs_fid *temp = NULL;
+ struct v9fs_fid *current_fid = NULL;
+ struct v9fs_fcall *fcall = NULL;
+
+ list_for_each_entry_safe(current_fid, temp, fid_list, list) {
+ if (v9fs_t_clunk
+ (current_fid->v9ses, current_fid->fid, &fcall))
+ dprintk(DEBUG_ERROR, "clunk failed: %s\n",
+ FCALL_ERROR(fcall));
+
+ v9fs_put_idpool(current_fid->fid,
+ ¤t_fid->v9ses->fidpool);
+
+ kfree(fcall);
+ v9fs_fid_destroy(current_fid);
+ }
+
+ kfree(dentry->d_fsdata); /* free the list_head */
+ }
+}
+
+struct dentry_operations v9fs_dentry_operations = {
+ .d_revalidate = v9fs_dentry_validate,
+ .d_release = v9fs_dentry_release,
+};