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LU-2744 build: fix 'data race condition' issues
[fs/lustre-release.git] / lustre / include / lustre_import.h
index ebcc46f..acb82fd 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2013, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre is a trademark of Sun Microsystems, Inc.
  */
+/** \defgroup obd_import PtlRPC import definitions
+ * Imports are client-side representation of remote obd target.
+ *
+ * @{
+ */
 
 #ifndef __IMPORT_H
 #define __IMPORT_H
 
+/** \defgroup export export
+ *
+ * @{
+ */
+
 #include <lustre_handles.h>
 #include <lustre/lustre_idl.h>
 
 
-/* Adaptive Timeout stuff */
+/**
+ * Adaptive Timeout stuff
+ *
+ * @{
+ */
 #define D_ADAPTTO D_OTHER
 #define AT_BINS 4                  /* "bin" means "N seconds of history" */
 #define AT_FLG_NOHIST 0x1          /* use last reported value only */
 
 struct adaptive_timeout {
-        time_t           at_binstart;         /* bin start time */
-        unsigned int     at_hist[AT_BINS];    /* timeout history bins */
-        unsigned int     at_flags;
-        unsigned int     at_current;          /* current timeout value */
-        unsigned int     at_worst_ever;       /* worst-ever timeout value */
-        time_t           at_worst_time;       /* worst-ever timeout timestamp */
-        cfs_spinlock_t   at_lock;
+       time_t          at_binstart;         /* bin start time */
+       unsigned int    at_hist[AT_BINS];    /* timeout history bins */
+       unsigned int    at_flags;
+       unsigned int    at_current;          /* current timeout value */
+       unsigned int    at_worst_ever;       /* worst-ever timeout value */
+       time_t          at_worst_time;       /* worst-ever timeout timestamp */
+       spinlock_t      at_lock;
+};
+
+struct ptlrpc_at_array {
+        cfs_list_t       *paa_reqs_array; /** array to hold requests */
+        __u32             paa_size;       /** the size of array */
+        __u32             paa_count;      /** the total count of reqs */
+        time_t            paa_deadline;   /** the earliest deadline of reqs */
+        __u32            *paa_reqs_count; /** the count of reqs in each entry */
 };
 
+#define IMP_AT_MAX_PORTALS 8
+struct imp_at {
+        int                     iat_portal[IMP_AT_MAX_PORTALS];
+        struct adaptive_timeout iat_net_latency;
+        struct adaptive_timeout iat_service_estimate[IMP_AT_MAX_PORTALS];
+};
+
+
+/** @} */
+
+/** Possible import states */
 enum lustre_imp_state {
         LUSTRE_IMP_CLOSED     = 1,
         LUSTRE_IMP_NEW        = 2,
@@ -69,14 +102,7 @@ enum lustre_imp_state {
         LUSTRE_IMP_EVICTED    = 10,
 };
 
-struct ptlrpc_at_array {
-        cfs_list_t       *paa_reqs_array; /* array to hold requests */
-        __u32             paa_size;       /* the size of array */
-        __u32             paa_count;      /* the total count of reqs */
-        time_t            paa_deadline;   /* earliest deadline of reqs */
-        __u32            *paa_reqs_count; /* count of reqs in each entry */
-};
-
+/** Returns test string representation of numeric import state \a state */
 static inline char * ptlrpc_import_state_name(enum lustre_imp_state state)
 {
         static char* import_state_names[] = {
@@ -89,26 +115,33 @@ static inline char * ptlrpc_import_state_name(enum lustre_imp_state state)
         return import_state_names[state];
 }
 
+/**
+ * List of import event types
+ */
 enum obd_import_event {
         IMP_EVENT_DISCON     = 0x808001,
         IMP_EVENT_INACTIVE   = 0x808002,
         IMP_EVENT_INVALIDATE = 0x808003,
         IMP_EVENT_ACTIVE     = 0x808004,
         IMP_EVENT_OCD        = 0x808005,
+        IMP_EVENT_DEACTIVATE = 0x808006,
+        IMP_EVENT_ACTIVATE   = 0x808007,
 };
 
+/**
+ * Definition of import connection structure
+ */
 struct obd_import_conn {
+        /** Item for linking connections together */
         cfs_list_t                oic_item;
+        /** Pointer to actual PortalRPC connection */
         struct ptlrpc_connection *oic_conn;
+        /** uuid of remote side */
         struct obd_uuid           oic_uuid;
-        __u64                     oic_last_attempt; /* jiffies, 64-bit */
-};
-
-#define IMP_AT_MAX_PORTALS 8
-struct imp_at {
-        int                     iat_portal[IMP_AT_MAX_PORTALS];
-        struct adaptive_timeout iat_net_latency;
-        struct adaptive_timeout iat_service_estimate[IMP_AT_MAX_PORTALS];
+        /**
+         * Time (64 bit jiffies) of last connection attempt on this connection
+         */
+        __u64                     oic_last_attempt;
 };
 
 /* state history */
@@ -118,71 +151,140 @@ struct import_state_hist {
         time_t                ish_time;
 };
 
+/**
+ * Defintion of PortalRPC import structure.
+ * Imports are representing client-side view to remote target.
+ */
 struct obd_import {
+        /** Local handle (== id) for this import. */
         struct portals_handle     imp_handle;
+        /** Reference counter */
         cfs_atomic_t              imp_refcount;
         struct lustre_handle      imp_dlm_handle; /* client's ldlm export */
+        /** Currently active connection */
         struct ptlrpc_connection *imp_connection;
+        /** PortalRPC client structure for this import */
         struct ptlrpc_client     *imp_client;
+        /** List element for linking into pinger chain */
         cfs_list_t                imp_pinger_chain;
-        cfs_list_t                imp_zombie_chain; /* queue for destruction */
+        /** List element for linking into chain for destruction */
+        cfs_list_t                imp_zombie_chain;
 
-        /* Lists of requests that are retained for replay, waiting for a reply,
+        /**
+         * Lists of requests that are retained for replay, waiting for a reply,
          * or waiting for recovery to complete, respectively.
+         * @{
          */
         cfs_list_t                imp_replay_list;
         cfs_list_t                imp_sending_list;
         cfs_list_t                imp_delayed_list;
+        /** @} */
 
+        /** obd device for this import */
         struct obd_device        *imp_obd;
+
+        /**
+         * some seciruty-related fields
+         * @{
+         */
         struct ptlrpc_sec        *imp_sec;
-        cfs_semaphore_t           imp_sec_mutex;
+       struct mutex              imp_sec_mutex;
         cfs_time_t                imp_sec_expire;
+        /** @} */
+
+        /** Wait queue for those who need to wait for recovery completion */
         cfs_waitq_t               imp_recovery_waitq;
 
+        /** Number of requests currently in-flight */
         cfs_atomic_t              imp_inflight;
+        /** Number of requests currently unregistering */
         cfs_atomic_t              imp_unregistering;
+        /** Number of replay requests inflight */
         cfs_atomic_t              imp_replay_inflight;
-        cfs_atomic_t              imp_inval_count;  /* in-progress invalidations */
+        /** Number of currently happening import invalidations */
+        cfs_atomic_t              imp_inval_count;
+        /** Numbner of request timeouts */
         cfs_atomic_t              imp_timeouts;
+        /** Current import state */
         enum lustre_imp_state     imp_state;
+        /** History of import states */
         struct import_state_hist  imp_state_hist[IMP_STATE_HIST_LEN];
         int                       imp_state_hist_idx;
+        /** Current import generation. Incremented on every reconnect */
         int                       imp_generation;
+        /** Incremented every time we send reconnection request */
         __u32                     imp_conn_cnt;
+       /** 
+        * \see ptlrpc_free_committed remembers imp_generation value here
+        * after a check to save on unnecessary replay list iterations
+        */
         int                       imp_last_generation_checked;
+        /** Last tranno we replayed */
         __u64                     imp_last_replay_transno;
+        /** Last transno committed on remote side */
         __u64                     imp_peer_committed_transno;
+        /**
+         * \see ptlrpc_free_committed remembers last_transno since its last
+         * check here and if last_transno did not change since last run of
+         * ptlrpc_free_committed and import generation is the same, we can
+         * skip looking for requests to remove from replay list as optimisation
+         */
         __u64                     imp_last_transno_checked;
+        /**
+         * Remote export handle. This is how remote side knows what export
+         * we are talking to. Filled from response to connect request
+         */
         struct lustre_handle      imp_remote_handle;
-        cfs_time_t                imp_next_ping;   /* jiffies */
-        __u64                     imp_last_success_conn;   /* jiffies, 64-bit */
+        /** When to perform next ping. time in jiffies. */
+        cfs_time_t                imp_next_ping;
+        /** When we last succesfully connected. time in 64bit jiffies */
+        __u64                     imp_last_success_conn;
 
-        /* all available obd_import_conn linked here */
+        /** List of all possible connection for import. */
         cfs_list_t                imp_conn_list;
+        /**
+         * Current connection. \a imp_connection is imp_conn_current->oic_conn
+         */
         struct obd_import_conn   *imp_conn_current;
 
-        /* Protects flags, level, generation, conn_cnt, *_list */
-        cfs_spinlock_t            imp_lock;
-
-        /* flags */
-        unsigned long             imp_no_timeout:1,       /* timeouts are disabled */
-                                  imp_invalid:1,          /* evicted */
-                                  imp_deactive:1,         /* administratively disabled */
-                                  imp_replayable:1,       /* try to recover the import */
-                                  imp_dlm_fake:1,         /* don't run recovery (timeout instead) */
-                                  imp_server_timeout:1,   /* use 1/2 timeout on MDS' OSCs */
-                                  imp_initial_recov:1,    /* retry the initial connection */
-                                  imp_initial_recov_bk:1, /* turn off init_recov after trying all failover nids */
-                                  imp_delayed_recovery:1, /* VBR: imp in delayed recovery */
-                                  imp_no_lock_replay:1,   /* VBR: if gap was found then no lock replays */
-                                  imp_vbr_failed:1,       /* recovery by versions was failed */
-                                  imp_force_verify:1,     /* force an immidiate ping */
-                                  imp_pingable:1,         /* pingable */
-                                  imp_resend_replay:1,    /* resend for replay */
-                                  imp_recon_bk:1,         /* turn off reconnect if all failovers fail */
-                                  imp_last_recon:1,       /* internally used by above */
-                                  imp_force_reconnect:1;  /* import must be reconnected instead of chouse new connection */
+        /** Protects flags, level, generation, conn_cnt, *_list */
+       spinlock_t                imp_lock;
+
+       /* flags */
+       unsigned long             imp_no_timeout:1, /* timeouts are disabled */
+                                 imp_invalid:1,    /* evicted */
+                                 /* administratively disabled */
+                                 imp_deactive:1,
+                                 /* try to recover the import */
+                                 imp_replayable:1,
+                                 /* don't run recovery (timeout instead) */
+                                 imp_dlm_fake:1,
+                                 /* use 1/2 timeout on MDS' OSCs */
+                                 imp_server_timeout:1,
+                                 /* VBR: imp in delayed recovery */
+                                 imp_delayed_recovery:1,
+                                 /* VBR: if gap was found then no lock replays
+                                  */
+                                 imp_no_lock_replay:1,
+                                 /* recovery by versions was failed */
+                                 imp_vbr_failed:1,
+                                 /* force an immidiate ping */
+                                 imp_force_verify:1,
+                                 /* force a scheduled ping */
+                                 imp_force_next_verify:1,
+                                 /* pingable */
+                                 imp_pingable:1,
+                                 /* resend for replay */
+                                 imp_resend_replay:1,
+                                 /* disable normal recovery, for test only. */
+                                 imp_no_pinger_recover:1,
+                                 /* need IR MNE swab */
+                                 imp_need_mne_swab:1,
+                                 /* import must be reconnected instead of
+                                  * chouse new connection */
+                                 imp_force_reconnect:1,
+                                 /* import has tried to connect with server */
+                                 imp_connect_tried:1;
         __u32                     imp_connect_op;
         struct obd_connect_data   imp_connect_data;
         __u64                     imp_connect_flags_orig;
@@ -200,6 +302,12 @@ struct obd_import {
 typedef void (*obd_import_callback)(struct obd_import *imp, void *closure,
                                     int event, void *event_arg, void *cb_data);
 
+/**
+ * Structure for import observer.
+ * It is possible to register "observer" on an import and every time
+ * something happens to an import (like connect/evict/disconnect)
+ * obderver will get its callback called with event type
+ */
 struct obd_import_observer {
         cfs_list_t           oio_chain;
         obd_import_callback  oio_cb;
@@ -227,16 +335,22 @@ static inline unsigned int at_timeout2est(unsigned int val)
         return (max((val << 2) / 5, 5U) - 4);
 }
 
-static inline void at_init(struct adaptive_timeout *at, int val, int flags) {
-        memset(at, 0, sizeof(*at));
+static inline void at_reset(struct adaptive_timeout *at, int val) {
+       spin_lock(&at->at_lock);
         at->at_current = val;
         at->at_worst_ever = val;
         at->at_worst_time = cfs_time_current_sec();
-        at->at_flags = flags;
-        cfs_spin_lock_init(&at->at_lock);
+       spin_unlock(&at->at_lock);
+}
+static inline void at_init(struct adaptive_timeout *at, int val, int flags) {
+       memset(at, 0, sizeof(*at));
+       spin_lock_init(&at->at_lock);
+       at->at_flags = flags;
+       at_reset(at, val);
 }
+extern unsigned int at_min;
 static inline int at_get(struct adaptive_timeout *at) {
-        return at->at_current;
+        return (at->at_current > at_min) ? at->at_current : at_min;
 }
 int at_measured(struct adaptive_timeout *at, unsigned int val);
 int import_at_get_index(struct obd_import *imp, int portal);
@@ -248,4 +362,8 @@ struct obd_export;
 extern struct obd_import *class_exp2cliimp(struct obd_export *);
 extern struct obd_import *class_conn2cliimp(struct lustre_handle *);
 
+/** @} import */
+
 #endif /* __IMPORT_H */
+
+/** @} obd_import */