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-rw-r--r--fs/orangefs/dcache.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/fs/orangefs/dcache.c b/fs/orangefs/dcache.c
new file mode 100644
index 000000000..5dfc4f3cf
--- /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,
+};