drivers/md/dm-vdo/indexer/index-session.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright 2023 Red Hat
   4  */
   5
   6 #ifndef UDS_INDEX_SESSION_H
   7 #define UDS_INDEX_SESSION_H
   8
   9 #include <linux/atomic.h>
  10 #include <linux/cache.h>
  11
  12 #include "thread-utils.h"
  13
  14 #include "config.h"
  15 #include "indexer.h"
  16
  17 /*
  18  * The index session mediates all interactions with a UDS index. Once the index session is created,
  19  * it can be used to open, close, suspend, or recreate an index. It implements the majority of the
  20  * functions in the top-level UDS API.
  21  *
  22  * If any deduplication request fails due to an internal error, the index is marked disabled. It
  23  * will not accept any further requests and can only be closed. Closing the index will clear the
  24  * disabled flag, and the index can then be reopened and recovered using the same index session.
  25  */
  26
  27 struct __aligned(L1_CACHE_BYTES) session_stats {
  28         /* Post requests that found an entry */
  29         u64 posts_found;
  30         /* Post requests found in the open chapter */
  31         u64 posts_found_open_chapter;
  32         /* Post requests found in the dense index */
  33         u64 posts_found_dense;
  34         /* Post requests found in the sparse index */
  35         u64 posts_found_sparse;
  36         /* Post requests that did not find an entry */
  37         u64 posts_not_found;
  38         /* Update requests that found an entry */
  39         u64 updates_found;
  40         /* Update requests that did not find an entry */
  41         u64 updates_not_found;
  42         /* Delete requests that found an entry */
  43         u64 deletions_found;
  44         /* Delete requests that did not find an entry */
  45         u64 deletions_not_found;
  46         /* Query requests that found an entry */
  47         u64 queries_found;
  48         /* Query requests that did not find an entry */
  49         u64 queries_not_found;
  50         /* Total number of requests */
  51         u64 requests;
  52 };
  53
  54 enum index_suspend_status {
  55         /* An index load has started but the index is not ready for use. */
  56         INDEX_OPENING = 0,
  57         /* The index is able to handle requests. */
  58         INDEX_READY,
  59         /* The index is attempting to suspend a rebuild. */
  60         INDEX_SUSPENDING,
  61         /* An index rebuild has been suspended. */
  62         INDEX_SUSPENDED,
  63         /* An index rebuild is being stopped in order to shut down. */
  64         INDEX_FREEING,
  65 };
  66
  67 struct index_load_context {
  68         struct mutex mutex;
  69         struct cond_var cond;
  70         enum index_suspend_status status;
  71 };
  72
  73 struct uds_index_session {
  74         unsigned int state;
  75         struct uds_index *index;
  76         struct uds_request_queue *callback_queue;
  77         struct uds_parameters parameters;
  78         struct index_load_context load_context;
  79         struct mutex request_mutex;
  80         struct cond_var request_cond;
  81         int request_count;
  82         struct session_stats stats;
  83 };
  84
  85 #endif /* UDS_INDEX_SESSION_H */