/* $NetBSD: rf_reconstruct.h,v 1.28 2011/05/02 07:29:18 mrg Exp $ */ /* * Copyright (c) 1995 Carnegie-Mellon University. * All rights reserved. * * Author: Mark Holland * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /********************************************************* * rf_reconstruct.h -- header file for reconstruction code *********************************************************/ #ifndef _RF__RF_RECONSTRUCT_H_ #define _RF__RF_RECONSTRUCT_H_ #include #include #include "rf_reconmap.h" #include "rf_psstatus.h" /* reconstruction configuration information */ struct RF_ReconConfig_s { unsigned numFloatingReconBufs; /* number of floating recon bufs to * use */ RF_HeadSepLimit_t headSepLimit; /* how far apart the heads are allow * to become, in parity stripes */ }; /* a reconstruction buffer */ struct RF_ReconBuffer_s { RF_Raid_t *raidPtr; /* void *to avoid recursive includes */ void *buffer; /* points to the data */ RF_StripeNum_t parityStripeID; /* the parity stripe that this data * relates to */ int which_ru; /* which reconstruction unit within the PSS */ RF_SectorNum_t failedDiskSectorOffset; /* the offset into the failed * disk */ RF_RowCol_t col; /* which disk this buffer belongs to or is * targeted at */ RF_StripeCount_t count; /* counts the # of SUs installed so far */ int priority; /* used to force hi priority recon */ RF_RbufType_t type; /* FORCED or FLOATING */ RF_ReconBuffer_t *next; /* used for buffer management */ void *arg; /* generic field for general use */ RF_RowCol_t spRow, spCol; /* spare disk to which this buf should * be written */ /* if dist sparing off, always identifies the replacement disk */ RF_SectorNum_t spOffset;/* offset into the spare disk */ /* if dist sparing off, identical to failedDiskSectorOffset */ RF_ReconParityStripeStatus_t *pssPtr; /* debug- pss associated with * issue-pending write */ }; /* a reconstruction event descriptor. The event types currently are: * RF_REVENT_READDONE -- a read operation has completed * RF_REVENT_WRITEDONE -- a write operation has completed * RF_REVENT_BUFREADY -- the buffer manager has produced a full buffer * RF_REVENT_BLOCKCLEAR -- a reconstruction blockage has been cleared * RF_REVENT_BUFCLEAR -- the buffer manager has released a process blocked on submission * RF_REVENT_SKIP -- we need to skip the current RU and go on to the next one, typ. b/c we found recon forced * RF_REVENT_FORCEDREADONE- a forced-reconstructoin read operation has completed */ typedef enum RF_Revent_e { RF_REVENT_READDONE, RF_REVENT_WRITEDONE, RF_REVENT_BUFREADY, RF_REVENT_BLOCKCLEAR, RF_REVENT_BUFCLEAR, RF_REVENT_HEADSEPCLEAR, RF_REVENT_SKIP, RF_REVENT_FORCEDREADDONE, RF_REVENT_READ_FAILED, RF_REVENT_WRITE_FAILED, RF_REVENT_FORCEDREAD_FAILED } RF_Revent_t; struct RF_ReconEvent_s { RF_Revent_t type; /* what kind of event has occurred */ RF_RowCol_t col; /* row ID is implicit in the queue in which * the event is placed */ void *arg; /* a generic argument */ RF_ReconEvent_t *next; }; /* * Reconstruction control information maintained per-disk * (for surviving disks) */ struct RF_PerDiskReconCtrl_s { RF_ReconCtrl_t *reconCtrl; RF_RowCol_t col; /* to make this structure self-identifying */ RF_StripeNum_t curPSID; /* the next parity stripe ID to check on this * disk */ RF_HeadSepLimit_t headSepCounter; /* counter used to control * maximum head separation */ RF_SectorNum_t diskOffset; /* the offset into the indicated disk * of the current PU */ RF_ReconUnitNum_t ru_count; /* this counts off the recon units * within each parity unit */ RF_ReconBuffer_t *rbuf; /* the recon buffer assigned to this disk */ }; /* main reconstruction control structure */ struct RF_ReconCtrl_s { RF_RaidReconDesc_t *reconDesc; RF_RowCol_t fcol; /* which column has failed */ RF_PerDiskReconCtrl_t *perDiskInfo; /* information maintained * per-disk */ RF_ReconMap_t *reconMap;/* map of what has/has not been reconstructed */ RF_RowCol_t spareCol; /* which of the spare disks we're using */ RF_StripeNum_t lastPSID;/* the ID of the last parity stripe we want * reconstructed */ int percentComplete;/* percentage completion of reconstruction */ RF_ReconUnitCount_t numRUsComplete; /* number of Reconstruction Units done */ RF_ReconUnitCount_t numRUsTotal; /* total number of Reconstruction Units */ int error; /* non-0 indicates that an error has occured during reconstruction, and the reconstruction is in the process of bailing out. */ /* reconstruction event queue */ RF_ReconEvent_t *eventQueue; /* queue of pending reconstruction * events */ rf_declare_mutex2(eq_mutex); /* mutex for locking event */ rf_declare_cond2(eq_cv); /* queue */ int eq_count; /* debug only */ /* reconstruction buffer management */ rf_declare_mutex2(rb_mutex); /* mutex/cv for messing */ rf_declare_cond2(rb_cv); /* around with recon buffers */ int rb_lock; /* 1 if someone is mucking with recon buffers, 0 otherwise */ int pending_writes; /* number of writes which have not completed */ RF_ReconBuffer_t *floatingRbufs; /* available floating * reconstruction buffers */ RF_ReconBuffer_t *committedRbufs; /* recon buffers that have * been committed to some * waiting disk */ RF_ReconBuffer_t *fullBufferList; /* full buffers waiting to be * written out */ RF_CallbackDesc_t *bufferWaitList; /* disks that are currently * blocked waiting for buffers */ /* parity stripe status table */ RF_PSStatusHeader_t *pssTable; /* stores the reconstruction status of * active parity stripes */ /* maximum-head separation control */ RF_HeadSepLimit_t minHeadSepCounter; /* the minimum hs counter over * all disks */ RF_CallbackDesc_t *headSepCBList; /* list of callbacks to be * done as minPSID advances */ /* performance monitoring */ struct timeval starttime; /* recon start time */ }; /* the default priority for reconstruction accesses */ #define RF_IO_RECON_PRIORITY RF_IO_LOW_PRIORITY int rf_ConfigureReconstruction(RF_ShutdownList_t **); int rf_ReconstructFailedDisk(RF_Raid_t *, RF_RowCol_t); int rf_ReconstructFailedDiskBasic(RF_Raid_t *, RF_RowCol_t); int rf_ReconstructInPlace(RF_Raid_t *, RF_RowCol_t); int rf_ContinueReconstructFailedDisk(RF_RaidReconDesc_t *); int rf_ForceOrBlockRecon(RF_Raid_t *, RF_AccessStripeMap_t *, void (*cbFunc) (RF_Raid_t *, void *), void *); int rf_UnblockRecon(RF_Raid_t *, RF_AccessStripeMap_t *); void rf_WakeupHeadSepCBWaiters(RF_Raid_t *); extern struct pool rf_reconbuffer_pool; #endif /* !_RF__RF_RECONSTRUCT_H_ */