From 5db11c21a929cd9d8c0484006efb1014fc723c93 Mon Sep 17 00:00:00 2001
From: Mike Marshall <hubcap@omnibond.com>
Date: Fri, 17 Jul 2015 10:38:12 -0400
Subject: Orangefs: kernel client part 2

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
---
 fs/orangefs/dcache.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 fs/orangefs/dcache.c

(limited to 'fs/orangefs/dcache.c')

diff --git a/fs/orangefs/dcache.c b/fs/orangefs/dcache.c
new file mode 100644
index 000000000000..9466b179bf24
--- /dev/null
+++ b/fs/orangefs/dcache.c
@@ -0,0 +1,142 @@
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Implementation of dentry (directory cache) functions.
+ */
+
+#include "protocol.h"
+#include "pvfs2-kernel.h"
+
+/* Returns 1 if dentry can still be trusted, else 0. */
+static int pvfs2_revalidate_lookup(struct dentry *dentry)
+{
+	struct dentry *parent_dentry = dget_parent(dentry);
+	struct inode *parent_inode = parent_dentry->d_inode;
+	struct pvfs2_inode_s *parent = PVFS2_I(parent_inode);
+	struct inode *inode = dentry->d_inode;
+	struct pvfs2_kernel_op_s *new_op;
+	int ret = 0;
+	int err = 0;
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__);
+
+	new_op = op_alloc(PVFS2_VFS_OP_LOOKUP);
+	if (!new_op)
+		goto out_put_parent;
+
+	new_op->upcall.req.lookup.sym_follow = PVFS2_LOOKUP_LINK_NO_FOLLOW;
+	new_op->upcall.req.lookup.parent_refn = parent->refn;
+	strncpy(new_op->upcall.req.lookup.d_name,
+		dentry->d_name.name,
+		PVFS2_NAME_LEN);
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s:%s:%d interrupt flag [%d]\n",
+		     __FILE__,
+		     __func__,
+		     __LINE__,
+		     get_interruptible_flag(parent_inode));
+
+	err = service_operation(new_op, "pvfs2_lookup",
+			get_interruptible_flag(parent_inode));
+	if (err)
+		goto out_drop;
+
+	if (new_op->downcall.status != 0 ||
+	    !match_handle(new_op->downcall.resp.lookup.refn.khandle, inode)) {
+		gossip_debug(GOSSIP_DCACHE_DEBUG,
+			"%s:%s:%d "
+			"lookup failure |%s| or no match |%s|.\n",
+			__FILE__,
+			__func__,
+			__LINE__,
+			new_op->downcall.status ? "true" : "false",
+			match_handle(new_op->downcall.resp.lookup.refn.khandle,
+					inode) ? "false" : "true");
+		gossip_debug(GOSSIP_DCACHE_DEBUG,
+			     "%s:%s:%d revalidate failed\n",
+			     __FILE__, __func__, __LINE__);
+		goto out_drop;
+	}
+
+	ret = 1;
+out_release_op:
+	op_release(new_op);
+out_put_parent:
+	dput(parent_dentry);
+	return ret;
+out_drop:
+	d_drop(dentry);
+	goto out_release_op;
+}
+
+/*
+ * Verify that dentry is valid.
+ *
+ * Should return 1 if dentry can still be trusted, else 0
+ */
+static int pvfs2_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode;
+	int ret = 0;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
+		     __func__, dentry);
+
+	/* find inode from dentry */
+	if (!dentry->d_inode) {
+		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
+			     __func__);
+		goto invalid_exit;
+	}
+
+	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: inode valid.\n", __func__);
+	inode = dentry->d_inode;
+
+	/*
+	 * first perform a lookup to make sure that the object not only
+	 * exists, but is still in the expected place in the name space
+	 */
+	if (!is_root_handle(inode)) {
+		if (!pvfs2_revalidate_lookup(dentry))
+			goto invalid_exit;
+	} else {
+		gossip_debug(GOSSIP_DCACHE_DEBUG,
+			     "%s: root handle, lookup skipped.\n",
+			     __func__);
+	}
+
+	/* now perform getattr */
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s: doing getattr: inode: %p, handle: %pU\n",
+		     __func__,
+		     inode,
+		     get_khandle_from_ino(inode));
+	ret = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
+	gossip_debug(GOSSIP_DCACHE_DEBUG,
+		     "%s: getattr %s (ret = %d), returning %s for dentry i_count=%d\n",
+		     __func__,
+		     (ret == 0 ? "succeeded" : "failed"),
+		     ret,
+		     (ret == 0 ? "valid" : "INVALID"),
+		     atomic_read(&inode->i_count));
+	if (ret != 0)
+		goto invalid_exit;
+
+	/* dentry is valid! */
+	return 1;
+
+invalid_exit:
+	return 0;
+}
+
+const struct dentry_operations pvfs2_dentry_operations = {
+	.d_revalidate = pvfs2_d_revalidate,
+};
-- 
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