1 files changed, 138 insertions, 0 deletions

diff --git a/fs/orangefs/dcache.c b/fs/orangefs/dcache.c
new file mode 100644
index 000000000000..5dfc4f3cfe68
--- /dev/null
+++ b/fs/orangefs/dcache.c
@@ -0,0 +1,138 @@
+/*
+ * (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 "orangefs-kernel.h"
+
+/* Returns 1 if dentry can still be trusted, else 0. */
+static int orangefs_revalidate_lookup(struct dentry *dentry)
+{
+        struct dentry *parent_dentry = dget_parent(dentry);
+        struct inode *parent_inode = parent_dentry->d_inode;
+        struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode);
+        struct inode *inode = dentry->d_inode;
+        struct orangefs_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(ORANGEFS_VFS_OP_LOOKUP);
+        if (!new_op)
+                goto out_put_parent;
+
+        new_op->upcall.req.lookup.sym_follow = ORANGEFS_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,
+                ORANGEFS_NAME_MAX);
+
+        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, "orangefs_lookup",
+                        get_interruptible_flag(parent_inode));
+
+        /* Positive dentry: reject if error or not the same inode. */
+        if (inode) {
+                if (err) {
+                        gossip_debug(GOSSIP_DCACHE_DEBUG,
+                            "%s:%s:%d lookup failure.\n",
+                            __FILE__, __func__, __LINE__);
+                        goto out_drop;
+                }
+                if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
+                    inode)) {
+                        gossip_debug(GOSSIP_DCACHE_DEBUG,
+                            "%s:%s:%d no match.\n",
+                            __FILE__, __func__, __LINE__);
+                        goto out_drop;
+                }
+
+        /* Negative dentry: reject if success or error other than ENOENT. */
+        } else {
+                gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
+                    __func__);
+                if (!err || err != -ENOENT) {
+                        if (new_op->downcall.status != 0)
+                                gossip_debug(GOSSIP_DCACHE_DEBUG,
+                                    "%s:%s:%d lookup failure.\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:
+        gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
+            __FILE__, __func__, __LINE__);
+        goto out_release_op;
+}
+
+/*
+ * Verify that dentry is valid.
+ *
+ * Should return 1 if dentry can still be trusted, else 0.
+ */
+static int orangefs_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+        int ret;
+
+        if (flags & LOOKUP_RCU)
+                return -ECHILD;
+
+        gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
+                     __func__, dentry);
+
+        /* skip root handle lookups. */
+        if (dentry->d_inode && is_root_handle(dentry->d_inode))
+                return 1;
+
+        /*
+         * If this passes, the positive dentry still exists or the negative
+         * dentry still does not exist.
+         */
+        if (!orangefs_revalidate_lookup(dentry))
+                return 0;
+
+        /* We do not need to continue with negative dentries. */
+        if (!dentry->d_inode)
+                goto out;
+
+        /* Now we must perform a getattr to validate the inode contents. */
+
+        ret = orangefs_inode_check_changed(dentry->d_inode);
+        if (ret < 0) {
+                gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
+                    __FILE__, __func__, __LINE__);
+                return 0;
+        }
+        if (ret == 0)
+                return 0;
+
+out:
+        gossip_debug(GOSSIP_DCACHE_DEBUG,
+            "%s: negative dentry or positive dentry and inode valid.\n",
+            __func__);
+        return 1;
+}
+
+const struct dentry_operations orangefs_dentry_operations = {
+        .d_revalidate = orangefs_d_revalidate,
+};