1 /*        $NetBSD: rf_reconstruct.h,v 1.32 2023/05/27 21:38:06 andvar Exp $     */
2 /*
3  * Copyright (c) 1995 Carnegie-Mellon University.
4  * All rights reserved.
5  *
6  * Author: Mark Holland
7  *
8  * Permission to use, copy, modify and distribute this software and
9  * its documentation is hereby granted, provided that both the copyright
10  * notice and this permission notice appear in all copies of the
11  * software, derivative works or modified versions, and any portions
12  * thereof, and that both notices appear in supporting documentation.
13  *
14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17  *
18  * Carnegie Mellon requests users of this software to return to
19  *
20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21  *  School of Computer Science
22  *  Carnegie Mellon University
23  *  Pittsburgh PA 15213-3890
24  *
25  * any improvements or extensions that they make and grant Carnegie the
26  * rights to redistribute these changes.
27  */
28 
29 /*********************************************************
30  * rf_reconstruct.h -- header file for reconstruction code
31  *********************************************************/
32 
33 #ifndef _RF__RF_RECONSTRUCT_H_
34 #define _RF__RF_RECONSTRUCT_H_
35 
36 #include <dev/raidframe/raidframevar.h>
37 #include <sys/time.h>
38 #include "rf_reconmap.h"
39 #include "rf_psstatus.h"
40 
41 /* reconstruction configuration information */
42 struct RF_ReconConfig_s {
43           unsigned numFloatingReconBufs;          /* number of floating recon bufs to
44                                                    * use */
45           RF_HeadSepLimit_t headSepLimit;         /* how far apart the heads are allow
46                                                    * to become, in parity stripes */
47 };
48 /* a reconstruction buffer */
49 struct RF_ReconBuffer_s {
50           RF_Raid_t *raidPtr; /* void *to avoid recursive includes */
51           void *buffer;                 /* points to the data */
52           RF_StripeNum_t parityStripeID;          /* the parity stripe that this data
53                                                    * relates to */
54           int     which_ru;   /* which reconstruction unit within the PSS */
55           RF_SectorNum_t failedDiskSectorOffset;  /* the offset into the failed
56                                                              * disk */
57           RF_RowCol_t col;    /* which disk this buffer belongs to or is
58                                          * targeted at */
59           RF_StripeCount_t count;       /* counts the # of SUs installed so far */
60           int     priority;   /* used to force hi priority recon */
61           RF_RbufType_t type; /* FORCED or FLOATING */
62           RF_ReconBuffer_t *next;       /* used for buffer management */
63           void   *arg;                  /* generic field for general use */
64           RF_RowCol_t spRow, spCol;     /* spare disk to which this buf should
65                                                    * be written */
66           /* if dist sparing off, always identifies the replacement disk */
67           RF_SectorNum_t spOffset;/* offset into the spare disk */
68           /* if dist sparing off, identical to failedDiskSectorOffset */
69           RF_ReconParityStripeStatus_t *pssPtr;   /* debug- pss associated with
70                                                              * issue-pending write */
71 };
72 /* a reconstruction event descriptor.  The event types currently are:
73  *    RF_REVENT_READDONE    -- a read operation has completed
74  *    RF_REVENT_WRITEDONE   -- a write operation has completed
75  *    RF_REVENT_BUFREADY    -- the buffer manager has produced a full buffer
76  *    RF_REVENT_BLOCKCLEAR  -- a reconstruction blockage has been cleared
77  *    RF_REVENT_BUFCLEAR    -- the buffer manager has released a process blocked on submission
78  *    RF_REVENT_SKIP        -- we need to skip the current RU and go on to the next one, typ. b/c we found recon forced
79  *    RF_REVENT_FORCEDREADONE- a forced-reconstruction read operation has completed
80  */
81 typedef enum RF_Revent_e {
82           RF_REVENT_READDONE,
83           RF_REVENT_WRITEDONE,
84           RF_REVENT_BUFREADY,
85           RF_REVENT_BLOCKCLEAR,
86           RF_REVENT_BUFCLEAR,
87           RF_REVENT_HEADSEPCLEAR,
88           RF_REVENT_SKIP,
89           RF_REVENT_FORCEDREADDONE,
90           RF_REVENT_READ_FAILED,
91           RF_REVENT_WRITE_FAILED,
92           RF_REVENT_FORCEDREAD_FAILED
93 }       RF_Revent_t;
94 
95 struct RF_ReconEvent_s {
96           RF_Revent_t type;   /* what kind of event has occurred */
97           RF_RowCol_t col;    /* row ID is implicit in the queue in which
98                                          * the event is placed */
99           void   *arg;                  /* a generic argument */
100           RF_ReconEvent_t *next;
101 };
102 /*
103  * Reconstruction control information maintained per-disk
104  * (for surviving disks)
105  */
106 struct RF_PerDiskReconCtrl_s {
107           RF_ReconCtrl_t *reconCtrl;
108           RF_RowCol_t col;    /* to make this structure self-identifying */
109           RF_StripeNum_t curPSID;       /* the next parity stripe ID to check on this
110                                          * disk */
111           RF_HeadSepLimit_t headSepCounter;       /* counter used to control
112                                                              * maximum head separation */
113           RF_SectorNum_t diskOffset;    /* the offset into the indicated disk
114                                                    * of the current PU */
115           RF_ReconUnitNum_t ru_count;   /* this counts off the recon units
116                                                    * within each parity unit */
117           RF_ReconBuffer_t *rbuf;       /* the recon buffer assigned to this disk */
118 };
119 /* main reconstruction control structure */
120 struct RF_ReconCtrl_s {
121           RF_RaidReconDesc_t *reconDesc;
122           RF_RowCol_t fcol;   /* which column has failed */
123           RF_PerDiskReconCtrl_t *perDiskInfo;     /* information maintained
124                                                              * per-disk */
125           RF_ReconMap_t *reconMap;/* map of what has/has not been reconstructed */
126           RF_RowCol_t spareCol;   /* which of the spare disks we're using */
127           RF_StripeNum_t lastPSID;/* the ID of the last parity stripe we want
128                                          * reconstructed */
129           int     percentComplete;/* percentage completion of reconstruction */
130           RF_ReconUnitCount_t  numRUsComplete; /* number of Reconstruction Units done */
131           RF_ReconUnitCount_t  numRUsTotal;    /* total number of Reconstruction Units */
132           int error;              /* non-0 indicates that an error has
133                                            occurred during reconstruction, and
134                                            the reconstruction is in the process of
135                                            bailing out. */
136 
137           /* reconstruction event queue */
138           RF_ReconEvent_t *eventQueue;  /* queue of pending reconstruction
139                                                    * events */
140           rf_declare_mutex2(eq_mutex);  /* mutex for locking event */
141           rf_declare_cond2(eq_cv);      /* queue */
142           int     eq_count;   /* debug only */
143 
144           /* reconstruction buffer management */
145           rf_declare_mutex2(rb_mutex);          /* mutex/cv for messing */
146           rf_declare_cond2(rb_cv);                /* around with recon buffers */
147           int rb_lock;                            /* 1 if someone is mucking
148                                                                with recon buffers,
149                                                                0 otherwise */
150           int pending_writes;                     /* number of writes which
151                                                                have not completed */
152           RF_ReconBuffer_t *floatingRbufs;        /* available floating
153                                                              * reconstruction buffers */
154           RF_ReconBuffer_t *committedRbufs;       /* recon buffers that have
155                                                              * been committed to some
156                                                              * waiting disk */
157           RF_ReconBuffer_t *fullBufferList;       /* full buffers waiting to be
158                                                              * written out */
159           RF_CallbackValueDesc_t *bufferWaitList; /* disks that are currently
160                                                              * blocked waiting for buffers */
161 
162           /* parity stripe status table */
163           RF_PSStatusHeader_t *pssTable;          /* stores the reconstruction status of
164                                                    * active parity stripes */
165 
166           /* maximum-head separation control */
167           RF_HeadSepLimit_t minHeadSepCounter;    /* the minimum hs counter over
168                                                              * all disks */
169           RF_CallbackValueDesc_t *headSepCBList;  /* list of callbacks to be
170                                                              * done as minPSID advances */
171 
172           /* performance monitoring */
173           struct timeval starttime;     /* recon start time */
174 };
175 /* the default priority for reconstruction accesses */
176 #define RF_IO_RECON_PRIORITY RF_IO_LOW_PRIORITY
177 
178 int rf_ConfigureReconstruction(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *);
179 int rf_ReconstructFailedDisk(RF_Raid_t *, RF_RowCol_t);
180 int rf_ReconstructFailedDiskBasic(RF_Raid_t *, RF_RowCol_t);
181 int rf_ReconstructInPlace(RF_Raid_t *, RF_RowCol_t);
182 int rf_ContinueReconstructFailedDisk(RF_RaidReconDesc_t *);
183 int rf_ForceOrBlockRecon(RF_Raid_t *, RF_AccessStripeMap_t *,
184                                void (*cbFunc) (void *), void *);
185 int rf_UnblockRecon(RF_Raid_t *, RF_AccessStripeMap_t *);
186 void rf_WakeupHeadSepCBWaiters(RF_Raid_t *);
187 
188 extern struct pool rf_reconbuffer_pool;
189 
190 #endif                                  /* !_RF__RF_RECONSTRUCT_H_ */
191