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-rw-r--r--drivers/md/dm-vdo/indexer/index-session.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/indexer/index-session.h b/drivers/md/dm-vdo/indexer/index-session.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef UDS_INDEX_SESSION_H
+#define UDS_INDEX_SESSION_H
+
+#include <linux/atomic.h>
+#include <linux/cache.h>
+
+#include "thread-utils.h"
+
+#include "config.h"
+#include "indexer.h"
+
+/*
+ * The index session mediates all interactions with a UDS index. Once the index session is created,
+ * it can be used to open, close, suspend, or recreate an index. It implements the majority of the
+ * functions in the top-level UDS API.
+ *
+ * If any deduplication request fails due to an internal error, the index is marked disabled. It
+ * will not accept any further requests and can only be closed. Closing the index will clear the
+ * disabled flag, and the index can then be reopened and recovered using the same index session.
+ */
+
+struct __aligned(L1_CACHE_BYTES) session_stats {
+ /* Post requests that found an entry */
+ u64 posts_found;
+ /* Post requests found in the open chapter */
+ u64 posts_found_open_chapter;
+ /* Post requests found in the dense index */
+ u64 posts_found_dense;
+ /* Post requests found in the sparse index */
+ u64 posts_found_sparse;
+ /* Post requests that did not find an entry */
+ u64 posts_not_found;
+ /* Update requests that found an entry */
+ u64 updates_found;
+ /* Update requests that did not find an entry */
+ u64 updates_not_found;
+ /* Delete requests that found an entry */
+ u64 deletions_found;
+ /* Delete requests that did not find an entry */
+ u64 deletions_not_found;
+ /* Query requests that found an entry */
+ u64 queries_found;
+ /* Query requests that did not find an entry */
+ u64 queries_not_found;
+ /* Total number of requests */
+ u64 requests;
+};
+
+enum index_suspend_status {
+ /* An index load has started but the index is not ready for use. */
+ INDEX_OPENING = 0,
+ /* The index is able to handle requests. */
+ INDEX_READY,
+ /* The index is attempting to suspend a rebuild. */
+ INDEX_SUSPENDING,
+ /* An index rebuild has been suspended. */
+ INDEX_SUSPENDED,
+ /* An index rebuild is being stopped in order to shut down. */
+ INDEX_FREEING,
+};
+
+struct index_load_context {
+ struct mutex mutex;
+ struct cond_var cond;
+ enum index_suspend_status status;
+};
+
+struct uds_index_session {
+ unsigned int state;
+ struct uds_index *index;
+ struct uds_request_queue *callback_queue;
+ struct uds_parameters parameters;
+ struct index_load_context load_context;
+ struct mutex request_mutex;
+ struct cond_var request_cond;
+ int request_count;
+ struct session_stats stats;
+};
+
+#endif /* UDS_INDEX_SESSION_H */