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NetBSD/sys/dev/raidframe/rf_reconstruct.c
oster 38a3987b69 RAIDframe, version 1.1, from the Parallel Data Laboratory at 
Carnegie Mellon University.  Full RAID implementation, including
levels 0, 1, 4, 5, 6, parity logging, and a few other goodies.
Ported to NetBSD by Greg Oster.
1998-11-13 04:20:26 +00:00

1595 lines
62 KiB
C
Raw Blame History

/* $NetBSD: rf_reconstruct.c,v 1.1 1998/11/13 04:20:33 oster 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.c -- code to perform on-line reconstruction
*
************************************************************/
/*
* :
* Log: rf_reconstruct.c,v
* Revision 1.65 1996/08/06 22:24:56 jimz
* get rid of sys/buf.h on linux
*
* Revision 1.64 1996/07/30 04:28:53 jimz
* include rf_types.h first
*
* Revision 1.63 1996/07/27 23:36:08 jimz
* Solaris port of simulator
*
* Revision 1.62 1996/07/17 21:00:58 jimz
* clean up timer interface, tracing
*
* Revision 1.61 1996/07/15 05:40:41 jimz
* some recon datastructure cleanup
* better handling of multiple failures
* added undocumented double-recon test
*
* Revision 1.60 1996/07/15 02:57:18 jimz
* added debugging (peek at first couple bytes of recon buffers
* as they go by)
*
* Revision 1.59 1996/07/13 00:00:59 jimz
* sanitized generalized reconstruction architecture
* cleaned up head sep, rbuf problems
*
* Revision 1.58 1996/07/11 19:08:00 jimz
* generalize reconstruction mechanism
* allow raid1 reconstructs via copyback (done with array
* quiesced, not online, therefore not disk-directed)
*
* Revision 1.57 1996/06/17 14:38:33 jimz
* properly #if out RF_DEMO code
* fix bug in MakeConfig that was causing weird behavior
* in configuration routines (config was not zeroed at start)
* clean up genplot handling of stacks
*
* Revision 1.56 1996/06/17 03:24:59 jimz
* include shutdown.h for define of now-macroized ShutdownCreate
*
* Revision 1.55 1996/06/11 10:58:36 jimz
* get rid of simulator-testcode artifacts
* add generic ReconDoneProc mechanism instead
*
* Revision 1.54 1996/06/10 14:18:58 jimz
* move user, throughput stats into per-array structure
*
* Revision 1.53 1996/06/10 11:55:47 jimz
* Straightened out some per-array/not-per-array distinctions, fixed
* a couple bugs related to confusion. Added shutdown lists. Removed
* layout shutdown function (now subsumed by shutdown lists).
*
* Revision 1.52 1996/06/09 02:36:46 jimz
* lots of little crufty cleanup- fixup whitespace
* issues, comment #ifdefs, improve typing in some
* places (esp size-related)
*
* Revision 1.51 1996/06/07 22:26:27 jimz
* type-ify which_ru (RF_ReconUnitNum_t)
*
* Revision 1.50 1996/06/07 21:33:04 jimz
* begin using consistent types for sector numbers,
* stripe numbers, row+col numbers, recon unit numbers
*
* Revision 1.49 1996/06/06 01:24:36 jimz
* don't get rid of reconCtrlPtr until we're done with it
*
* Revision 1.48 1996/06/05 18:06:02 jimz
* Major code cleanup. The Great Renaming is now done.
* Better modularity. Better typing. Fixed a bunch of
* synchronization bugs. Made a lot of global stuff
* per-desc or per-array. Removed dead code.
*
* Revision 1.47 1996/06/03 23:28:26 jimz
* more bugfixes
* check in tree to sync for IPDS runs with current bugfixes
* there still may be a problem with threads in the script test
* getting I/Os stuck- not trivially reproducible (runs ~50 times
* in a row without getting stuck)
*
* Revision 1.46 1996/06/02 17:31:48 jimz
* Moved a lot of global stuff into array structure, where it belongs.
* Fixed up paritylogging, pss modules in this manner. Some general
* code cleanup. Removed lots of dead code, some dead files.
*
* Revision 1.45 1996/05/31 22:26:54 jimz
* fix a lot of mapping problems, memory allocation problems
* found some weird lock issues, fixed 'em
* more code cleanup
*
* Revision 1.44 1996/05/30 23:22:16 jimz
* bugfixes of serialization, timing problems
* more cleanup
*
* Revision 1.43 1996/05/30 11:29:41 jimz
* Numerous bug fixes. Stripe lock release code disagreed with the taking code
* about when stripes should be locked (I made it consistent: no parity, no lock)
* There was a lot of extra serialization of I/Os which I've removed- a lot of
* it was to calculate values for the cache code, which is no longer with us.
* More types, function, macro cleanup. Added code to properly quiesce the array
* on shutdown. Made a lot of stuff array-specific which was (bogusly) general
* before. Fixed memory allocation, freeing bugs.
*
* Revision 1.42 1996/05/27 18:56:37 jimz
* more code cleanup
* better typing
* compiles in all 3 environments
*
* Revision 1.41 1996/05/24 22:17:04 jimz
* continue code + namespace cleanup
* typed a bunch of flags
*
* Revision 1.40 1996/05/24 04:40:40 jimz
* don't do demoMode stuff in kernel
*
* Revision 1.39 1996/05/24 01:59:45 jimz
* another checkpoint in code cleanup for release
* time to sync kernel tree
*
* Revision 1.38 1996/05/23 21:46:35 jimz
* checkpoint in code cleanup (release prep)
* lots of types, function names have been fixed
*
* Revision 1.37 1996/05/23 00:33:23 jimz
* code cleanup: move all debug decls to rf_options.c, all extern
* debug decls to rf_options.h, all debug vars preceded by rf_
*
* Revision 1.36 1996/05/18 19:51:34 jimz
* major code cleanup- fix syntax, make some types consistent,
* add prototypes, clean out dead code, et cetera
*
* Revision 1.35 1996/05/01 16:28:16 jimz
* don't include ccmn.h
*
* Revision 1.34 1995/12/12 18:10:06 jimz
* MIN -> RF_MIN, MAX -> RF_MAX, ASSERT -> RF_ASSERT
* fix 80-column brain damage in comments
*
* Revision 1.33 1995/12/06 15:05:09 root
* added copyright info
*
* Revision 1.32 1995/11/17 19:04:11 wvcii
* added prototyping to ComputePSDiskOffsets
* prow and pcol now type int (were u_int)
*
* Revision 1.31 1995/11/17 01:39:35 amiri
* isolated some demo related stuff
*
* Revision 1.30 1995/10/18 19:33:14 amiri
* removed fflush (stdin/stdout) calls from ReconstructFailedDisk
*
* Revision 1.29 1995/10/11 10:20:33 jimz
* #if 0'd problem code for sigmetrics
*
* Revision 1.28 1995/10/10 23:18:15 amiri
* added fflushes to stdin/stdout before requesting
* input in demo mode.
*
* Revision 1.27 1995/10/10 19:24:47 amiri
* took out update_mode (for demo) from
* KERNEL source.
*
* Revision 1.26 1995/10/09 23:35:48 amiri
* added support for more meters in recon. demo
*
* Revision 1.25 1995/07/03 18:14:30 holland
* changed the way the number of floating recon bufs &
* the head sep limit get set
*
* Revision 1.24 1995/07/02 15:07:42 holland
* bug fixes related to getting distributed sparing numbers
*
* Revision 1.23 1995/06/23 13:36:36 robby
* updeated to prototypes in rf_layout.h
*
*/
#ifdef _KERNEL
#define KERNEL
#endif
#include "rf_types.h"
#include <sys/time.h>
#ifndef LINUX
#include <sys/buf.h>
#endif /* !LINUX */
#include <sys/errno.h>
#include "rf_raid.h"
#include "rf_reconutil.h"
#include "rf_revent.h"
#include "rf_reconbuffer.h"
#include "rf_threadid.h"
#include "rf_acctrace.h"
#include "rf_etimer.h"
#include "rf_dag.h"
#include "rf_desc.h"
#include "rf_general.h"
#include "rf_freelist.h"
#include "rf_debugprint.h"
#include "rf_driver.h"
#include "rf_utils.h"
#include "rf_cpuutil.h"
#include "rf_shutdown.h"
#include "rf_sys.h"
#if RF_DEMO > 0
#include "rf_demo.h"
#endif /* RF_DEMO > 0 */
#ifdef KERNEL
#include "rf_kintf.h"
#endif /* KERNEL */
/* setting these to -1 causes them to be set to their default values if not set by debug options */
#define Dprintf(s) if (rf_reconDebug) rf_debug_printf(s,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf1(s,a) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf2(s,a,b) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf3(s,a,b,c) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),NULL,NULL,NULL,NULL,NULL)
#define Dprintf4(s,a,b,c,d) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),NULL,NULL,NULL,NULL)
#define Dprintf5(s,a,b,c,d,e) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),NULL,NULL,NULL)
#define Dprintf6(s,a,b,c,d,e,f) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),NULL,NULL)
#define Dprintf7(s,a,b,c,d,e,f,g) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),NULL)
#define Dprintf8(s,a,b,c,d,e,f,g,h) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),(void *)((unsigned long)h))
#define DDprintf1(s,a) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define DDprintf2(s,a,b) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
#define DDprintf3(s,a,b,c) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),NULL,NULL,NULL,NULL,NULL)
#define DDprintf4(s,a,b,c,d) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),NULL,NULL,NULL,NULL)
#define DDprintf5(s,a,b,c,d,e) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),NULL,NULL,NULL)
#define DDprintf6(s,a,b,c,d,e,f) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),NULL,NULL)
#define DDprintf7(s,a,b,c,d,e,f,g) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),NULL)
#define DDprintf8(s,a,b,c,d,e,f,g,h) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),(void *)((unsigned long)h))
#ifdef KERNEL
static RF_Thread_t recon_thr_handle;
static int recon_thread_initialized = 0;
#endif /* KERNEL */
static RF_FreeList_t *rf_recond_freelist;
#define RF_MAX_FREE_RECOND 4
#define RF_RECOND_INC 1
static RF_RaidReconDesc_t *AllocRaidReconDesc(RF_Raid_t *raidPtr,
RF_RowCol_t row, RF_RowCol_t col, RF_RaidDisk_t *spareDiskPtr,
int numDisksDone, RF_RowCol_t srow, RF_RowCol_t scol);
static void FreeReconDesc(RF_RaidReconDesc_t *reconDesc);
static int ProcessReconEvent(RF_Raid_t *raidPtr, RF_RowCol_t frow,
RF_ReconEvent_t *event);
static int IssueNextReadRequest(RF_Raid_t *raidPtr, RF_RowCol_t row,
RF_RowCol_t col);
static int TryToRead(RF_Raid_t *raidPtr, RF_RowCol_t row, RF_RowCol_t col);
static int ComputePSDiskOffsets(RF_Raid_t *raidPtr, RF_StripeNum_t psid,
RF_RowCol_t row, RF_RowCol_t col, RF_SectorNum_t *outDiskOffset,
RF_SectorNum_t *outFailedDiskSectorOffset, RF_RowCol_t *spRow,
RF_RowCol_t *spCol, RF_SectorNum_t *spOffset);
static int IssueNextWriteRequest(RF_Raid_t *raidPtr, RF_RowCol_t row);
static int ReconReadDoneProc(void *arg, int status);
static int ReconWriteDoneProc(void *arg, int status);
static void CheckForNewMinHeadSep(RF_Raid_t *raidPtr, RF_RowCol_t row,
RF_HeadSepLimit_t hsCtr);
static int CheckHeadSeparation(RF_Raid_t *raidPtr, RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t row, RF_RowCol_t col, RF_HeadSepLimit_t hsCtr,
RF_ReconUnitNum_t which_ru);
static int CheckForcedOrBlockedReconstruction(RF_Raid_t *raidPtr,
RF_ReconParityStripeStatus_t *pssPtr, RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t row, RF_RowCol_t col, RF_StripeNum_t psid,
RF_ReconUnitNum_t which_ru);
static void ForceReconReadDoneProc(void *arg, int status);
static void rf_ShutdownReconstruction(void *);
struct RF_ReconDoneProc_s {
void (*proc)(RF_Raid_t *, void *);
void *arg;
RF_ReconDoneProc_t *next;
};
static RF_FreeList_t *rf_rdp_freelist;
#define RF_MAX_FREE_RDP 4
#define RF_RDP_INC 1
static void SignalReconDone(RF_Raid_t *raidPtr)
{
RF_ReconDoneProc_t *p;
RF_LOCK_MUTEX(raidPtr->recon_done_proc_mutex);
for(p=raidPtr->recon_done_procs;p;p=p->next) {
p->proc(raidPtr, p->arg);
}
RF_UNLOCK_MUTEX(raidPtr->recon_done_proc_mutex);
}
int rf_RegisterReconDoneProc(
RF_Raid_t *raidPtr,
void (*proc)(RF_Raid_t *, void *),
void *arg,
RF_ReconDoneProc_t **handlep)
{
RF_ReconDoneProc_t *p;
RF_FREELIST_GET(rf_rdp_freelist,p,next,(RF_ReconDoneProc_t *));
if (p == NULL)
return(ENOMEM);
p->proc = proc;
p->arg = arg;
RF_LOCK_MUTEX(raidPtr->recon_done_proc_mutex);
p->next = raidPtr->recon_done_procs;
raidPtr->recon_done_procs = p;
RF_UNLOCK_MUTEX(raidPtr->recon_done_proc_mutex);
if (handlep)
*handlep = p;
return(0);
}
/*****************************************************************************************
*
* sets up the parameters that will be used by the reconstruction process
* currently there are none, except for those that the layout-specific
* configuration (e.g. rf_ConfigureDeclustered) routine sets up.
*
* in the kernel, we fire off the recon thread.
*
****************************************************************************************/
static void rf_ShutdownReconstruction(ignored)
void *ignored;
{
RF_FREELIST_DESTROY(rf_recond_freelist,next,(RF_RaidReconDesc_t *));
RF_FREELIST_DESTROY(rf_rdp_freelist,next,(RF_ReconDoneProc_t *));
}
int rf_ConfigureReconstruction(listp)
RF_ShutdownList_t **listp;
{
int rc;
RF_FREELIST_CREATE(rf_recond_freelist, RF_MAX_FREE_RECOND,
RF_RECOND_INC, sizeof(RF_RaidReconDesc_t));
if (rf_recond_freelist == NULL)
return(ENOMEM);
RF_FREELIST_CREATE(rf_rdp_freelist, RF_MAX_FREE_RDP,
RF_RDP_INC, sizeof(RF_ReconDoneProc_t));
if (rf_rdp_freelist == NULL) {
RF_FREELIST_DESTROY(rf_recond_freelist,next,(RF_RaidReconDesc_t *));
return(ENOMEM);
}
rc = rf_ShutdownCreate(listp, rf_ShutdownReconstruction, NULL);
if (rc) {
RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
__FILE__, __LINE__, rc);
rf_ShutdownReconstruction(NULL);
return(rc);
}
#ifdef KERNEL
if (!recon_thread_initialized) {
RF_CREATE_THREAD(recon_thr_handle, rf_ReconKernelThread, NULL);
recon_thread_initialized = 1;
}
#endif /* KERNEL */
return(0);
}
static RF_RaidReconDesc_t *AllocRaidReconDesc(raidPtr, row, col, spareDiskPtr, numDisksDone, srow, scol)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_RowCol_t col;
RF_RaidDisk_t *spareDiskPtr;
int numDisksDone;
RF_RowCol_t srow;
RF_RowCol_t scol;
{
RF_RaidReconDesc_t *reconDesc;
RF_FREELIST_GET(rf_recond_freelist,reconDesc,next,(RF_RaidReconDesc_t *));
reconDesc->raidPtr = raidPtr;
reconDesc->row = row;
reconDesc->col = col;
reconDesc->spareDiskPtr=spareDiskPtr;
reconDesc->numDisksDone=numDisksDone;
reconDesc->srow=srow;
reconDesc->scol=scol;
reconDesc->state = 0;
reconDesc->next = NULL;
return(reconDesc);
}
static void FreeReconDesc(reconDesc)
RF_RaidReconDesc_t *reconDesc;
{
#if RF_RECON_STATS > 0
printf("RAIDframe: %lu recon event waits, %lu recon delays\n",
(long)reconDesc->numReconEventWaits, (long)reconDesc->numReconExecDelays);
#endif /* RF_RECON_STATS > 0 */
#ifdef KERNEL
printf("RAIDframe: %lu max exec ticks\n",
(long)reconDesc->maxReconExecTicks);
#endif /* KERNEL */
#if (RF_RECON_STATS > 0) || defined(KERNEL)
printf("\n");
#endif /* (RF_RECON_STATS > 0) || KERNEL */
RF_FREELIST_FREE(rf_recond_freelist,reconDesc,next);
}
/*****************************************************************************************
*
* primary routine to reconstruct a failed disk. This should be called from
* within its own thread. It won't return until reconstruction completes,
* fails, or is aborted.
****************************************************************************************/
int rf_ReconstructFailedDisk(raidPtr, row, col)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_RowCol_t col;
{
#ifdef SIMULATE
RF_PendingRecon_t *pend;
RF_RowCol_t r, c;
#endif /* SIMULATE */
RF_LayoutSW_t *lp;
int rc;
lp = raidPtr->Layout.map;
if (lp->SubmitReconBuffer) {
/*
* The current infrastructure only supports reconstructing one
* disk at a time for each array.
*/
#ifdef SIMULATE
if (raidPtr->reconInProgress) {
RF_Malloc(pend, sizeof(RF_PendingRecon_t), (RF_PendingRecon_t *));
pend->row = row;
pend->col = col;
pend->next = raidPtr->pendingRecon;
raidPtr->pendingRecon = pend;
/* defer until current recon completes */
return(0);
}
raidPtr->reconInProgress++;
#else /* SIMULATE */
RF_LOCK_MUTEX(raidPtr->mutex);
while (raidPtr->reconInProgress) {
RF_WAIT_COND(raidPtr->waitForReconCond, raidPtr->mutex);
}
raidPtr->reconInProgress++;
RF_UNLOCK_MUTEX(raidPtr->mutex);
#endif /* SIMULATE */
rc = rf_ReconstructFailedDiskBasic(raidPtr, row, col);
}
else {
RF_ERRORMSG1("RECON: no way to reconstruct failed disk for arch %c\n",
lp->parityConfig);
rc = EIO;
}
#ifdef SIMULATE
pend = raidPtr->pendingRecon;
if (pend) {
/* launch next recon */
raidPtr->pendingRecon = pend->next;
r = pend->row;
c = pend->col;
RF_Free(pend, sizeof(RF_PendingRecon_t));
return(rf_ReconstructFailedDisk(raidPtr, r, c));
}
#else /* SIMULATE */
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_SIGNAL_COND(raidPtr->waitForReconCond);
#if 1
#if defined(__NetBSD__) && defined(_KERNEL)
wakeup(&raidPtr->waitForReconCond); /* XXX Methinks this will be needed
at some point... GO*/
#endif
#endif
#endif /* SIMULATE */
return(rc);
}
int rf_ReconstructFailedDiskBasic(raidPtr, row, col)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_RowCol_t col;
{
RF_RaidDisk_t *spareDiskPtr = NULL;
RF_RaidReconDesc_t *reconDesc;
RF_RowCol_t srow, scol;
int numDisksDone=0, rc;
/* first look for a spare drive onto which to reconstruct the data */
/* spare disk descriptors are stored in row 0. This may have to change eventually */
RF_LOCK_MUTEX(raidPtr->mutex);
RF_ASSERT (raidPtr->Disks[row][col].status == rf_ds_failed);
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
if (raidPtr->status[row] != rf_rs_degraded) {
RF_ERRORMSG2("Unable to reconstruct disk at row %d col %d because status not degraded\n",row,col);
RF_UNLOCK_MUTEX(raidPtr->mutex);
return(EINVAL);
}
srow = row;
scol = (-1);
}
else {
srow = 0;
for (scol=raidPtr->numCol; scol<raidPtr->numCol + raidPtr->numSpare; scol++) {
if (raidPtr->Disks[srow][scol].status == rf_ds_spare) {
spareDiskPtr = &raidPtr->Disks[srow][scol];
spareDiskPtr->status = rf_ds_used_spare;
break;
}
}
if (!spareDiskPtr) {
RF_ERRORMSG2("Unable to reconstruct disk at row %d col %d because no spares are available\n",row,col);
RF_UNLOCK_MUTEX(raidPtr->mutex);
return(ENOSPC);
}
#if RF_DEMO > 0
if (!rf_demoMode) {
#endif /* RF_DEMO > 0 */
printf("RECON: initiating reconstruction on row %d col %d -> spare at row %d col %d\n",row, col, srow, scol);
#if RF_DEMO > 0
}
#endif /* RF_DEMO > 0 */
}
RF_UNLOCK_MUTEX(raidPtr->mutex);
reconDesc = AllocRaidReconDesc((void *) raidPtr, row, col,spareDiskPtr, numDisksDone, srow , scol);
raidPtr->reconDesc = (void *) reconDesc;
#if RF_RECON_STATS > 0
reconDesc->hsStallCount = 0;
reconDesc->numReconExecDelays = 0;
reconDesc->numReconEventWaits = 0;
#endif /* RF_RECON_STATS > 0 */
#ifdef KERNEL
reconDesc->reconExecTimerRunning = 0;
reconDesc->reconExecTicks = 0;
reconDesc->maxReconExecTicks = 0;
#endif /* KERNEL */
#if RF_DEMO > 0 && !defined(SIMULATE)
if (rf_demoMode) {
char cbuf[10];
printf("About to start reconstruction, hit return to continue:");
gets(cbuf);
}
#endif /* RF_DEMO > 0 && !SIMULATE */
rc = rf_ContinueReconstructFailedDisk(reconDesc);
return(rc);
}
int rf_ContinueReconstructFailedDisk(reconDesc)
RF_RaidReconDesc_t *reconDesc;
{
RF_Raid_t *raidPtr=reconDesc->raidPtr;
RF_RowCol_t row=reconDesc->row;
RF_RowCol_t col=reconDesc->col;
RF_RowCol_t srow=reconDesc->srow;
RF_RowCol_t scol=reconDesc->scol;
RF_ReconMap_t *mapPtr;
RF_ReconEvent_t *event;
struct timeval etime, elpsd;
unsigned long xor_s, xor_resid_us;
int retcode,i, ds;
switch (reconDesc->state)
{
case 0:
raidPtr->accumXorTimeUs = 0;
/* create one trace record per physical disk */
RF_Malloc(raidPtr->recon_tracerecs, raidPtr->numCol * sizeof(RF_AccTraceEntry_t), (RF_AccTraceEntry_t *));
/* quiesce the array prior to starting recon. this is needed to assure no nasty interactions
* with pending user writes. We need to do this before we change the disk or row status.
*/
reconDesc->state=1;
Dprintf("RECON: begin request suspend\n");
retcode = rf_SuspendNewRequestsAndWait(raidPtr);
Dprintf("RECON: end request suspend\n");
rf_StartUserStats(raidPtr); /* zero out the stats kept on user accs */
#ifdef SIMULATE
if (retcode) return(0);
#endif /* SIMULATE */
/* fall through to state 1 */
case 1:
RF_LOCK_MUTEX(raidPtr->mutex);
/* create the reconstruction control pointer and install it in the right slot */
raidPtr->reconControl[row] = rf_MakeReconControl(reconDesc, row, col, srow, scol);
mapPtr=raidPtr->reconControl[row]->reconMap;
raidPtr->status[row] = rf_rs_reconstructing;
raidPtr->Disks[row][col].status = rf_ds_reconstructing;
raidPtr->Disks[row][col].spareRow = srow;
raidPtr->Disks[row][col].spareCol = scol;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_GETTIME(raidPtr->reconControl[row]->starttime);
#if RF_DEMO > 0
if (rf_demoMode) {
rf_demo_update_mode(RF_DEMO_RECON);
rf_startup_recon_demo(rf_demoMeterVpos, raidPtr->numCol,
raidPtr->Layout.numDataCol+raidPtr->Layout.numParityCol, 0);
}
#endif /* RF_DEMO > 0 */
/* now start up the actual reconstruction: issue a read for each surviving disk */
rf_start_cpu_monitor();
reconDesc->numDisksDone = 0;
for (i=0; i<raidPtr->numCol; i++) {
if (i != col) {
/* find and issue the next I/O on the indicated disk */
if (IssueNextReadRequest(raidPtr, row, i)) {
Dprintf2("RECON: done issuing for r%d c%d\n", row, i);
reconDesc->numDisksDone++;
}
}
}
case 2:
Dprintf("RECON: resume requests\n");
rf_ResumeNewRequests(raidPtr);
reconDesc->state=3;
case 3:
/* process reconstruction events until all disks report that they've completed all work */
mapPtr=raidPtr->reconControl[row]->reconMap;
while (reconDesc->numDisksDone < raidPtr->numCol-1) {
event = rf_GetNextReconEvent(reconDesc, row, (void (*)(void *))rf_ContinueReconstructFailedDisk,reconDesc);
#ifdef SIMULATE
if (event==NULL) {return(0);}
#else /* SIMULATE */
RF_ASSERT(event);
#endif /* SIMULATE */
if (ProcessReconEvent(raidPtr, row, event)) reconDesc->numDisksDone++;
raidPtr->reconControl[row]->percentComplete = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 100 / mapPtr->totalRUs);
#if RF_DEMO > 0
if (rf_prReconSched || rf_demoMode)
#else /* RF_DEMO > 0 */
if (rf_prReconSched)
#endif /* RF_DEMO > 0 */
{
rf_PrintReconSchedule(raidPtr->reconControl[row]->reconMap, &(raidPtr->reconControl[row]->starttime));
}
}
reconDesc->state=4;
case 4:
mapPtr=raidPtr->reconControl[row]->reconMap;
if (rf_reconDebug) {
printf("RECON: all reads completed\n");
}
/* at this point all the reads have completed. We now wait for any pending writes
* to complete, and then we're done
*/
while (rf_UnitsLeftToReconstruct(raidPtr->reconControl[row]->reconMap) > 0) {
event = rf_GetNextReconEvent(reconDesc, row, (void (*)(void *))rf_ContinueReconstructFailedDisk,reconDesc);
#ifdef SIMULATE
if (event==NULL) {return(0);}
#else /* SIMULATE */
RF_ASSERT(event);
#endif /* SIMULATE */
(void) ProcessReconEvent(raidPtr, row, event); /* ignore return code */
raidPtr->reconControl[row]->percentComplete = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 100 / mapPtr->totalRUs);
#if RF_DEMO > 0
if (rf_prReconSched || rf_demoMode)
#else /* RF_DEMO > 0 */
if (rf_prReconSched)
#endif /* RF_DEMO > 0 */
{
rf_PrintReconSchedule(raidPtr->reconControl[row]->reconMap, &(raidPtr->reconControl[row]->starttime));
}
}
reconDesc->state=5;
case 5:
rf_stop_cpu_monitor();
/* Success: mark the dead disk as reconstructed. We quiesce the array here to assure no
* nasty interactions with pending user accesses when we free up the psstatus structure
* as part of FreeReconControl()
*/
reconDesc->state=6;
retcode = rf_SuspendNewRequestsAndWait(raidPtr);
rf_StopUserStats(raidPtr);
rf_PrintUserStats(raidPtr); /* print out the stats on user accs accumulated during recon */
#ifdef SIMULATE
if (retcode) return(0);
#endif /* SIMULATE */
/* fall through to state 6 */
case 6:
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->numFailures--;
ds = (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE);
raidPtr->Disks[row][col].status = (ds) ? rf_ds_dist_spared : rf_ds_spared;
raidPtr->status[row] = (ds) ? rf_rs_reconfigured : rf_rs_optimal;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_GETTIME(etime);
RF_TIMEVAL_DIFF(&(raidPtr->reconControl[row]->starttime), &etime, &elpsd);
/* XXX -- why is state 7 different from state 6 if there is no return() here? -- XXX
* Note that I set elpsd above & use it below, so if you put a return
* here you'll have to fix this. (also, FreeReconControl is called below)
*/
case 7:
rf_ResumeNewRequests(raidPtr);
#if RF_DEMO > 0
if (rf_demoMode) {
rf_finish_recon_demo(&elpsd);
}
else {
#endif /* RF_DEMO > 0 */
printf("Reconstruction of disk at row %d col %d completed and spare disk reassigned\n", row, col);
xor_s = raidPtr->accumXorTimeUs/1000000;
xor_resid_us = raidPtr->accumXorTimeUs%1000000;
printf("Recon time was %d.%06d seconds, accumulated XOR time was %ld us (%ld.%06ld)\n",
(int)elpsd.tv_sec,(int)elpsd.tv_usec,raidPtr->accumXorTimeUs,xor_s,xor_resid_us);
printf(" (start time %d sec %d usec, end time %d sec %d usec)\n",
(int)raidPtr->reconControl[row]->starttime.tv_sec,
(int)raidPtr->reconControl[row]->starttime.tv_usec,
(int)etime.tv_sec, (int)etime.tv_usec);
rf_print_cpu_util("reconstruction");
#if RF_RECON_STATS > 0
printf("Total head-sep stall count was %d\n",
(int)reconDesc->hsStallCount);
#endif /* RF_RECON_STATS > 0 */
#if RF_DEMO > 0
}
#endif /* RF_DEMO > 0 */
rf_FreeReconControl(raidPtr, row);
RF_Free(raidPtr->recon_tracerecs, raidPtr->numCol * sizeof(RF_AccTraceEntry_t));
FreeReconDesc(reconDesc);
}
SignalReconDone(raidPtr);
return (0);
}
/*****************************************************************************************
* do the right thing upon each reconstruction event.
* returns nonzero if and only if there is nothing left unread on the indicated disk
****************************************************************************************/
static int ProcessReconEvent(raidPtr, frow, event)
RF_Raid_t *raidPtr;
RF_RowCol_t frow;
RF_ReconEvent_t *event;
{
int retcode = 0, submitblocked;
RF_ReconBuffer_t *rbuf;
RF_SectorCount_t sectorsPerRU;
Dprintf1("RECON: ProcessReconEvent type %d\n", event->type);
switch(event->type) {
/* a read I/O has completed */
case RF_REVENT_READDONE:
rbuf = raidPtr->reconControl[frow]->perDiskInfo[event->col].rbuf;
Dprintf3("RECON: READDONE EVENT: row %d col %d psid %ld\n",
frow, event->col, rbuf->parityStripeID);
Dprintf7("RECON: done read psid %ld buf %lx %02x %02x %02x %02x %02x\n",
rbuf->parityStripeID, rbuf->buffer, rbuf->buffer[0]&0xff, rbuf->buffer[1]&0xff,
rbuf->buffer[2]&0xff, rbuf->buffer[3]&0xff, rbuf->buffer[4]&0xff);
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
submitblocked = rf_SubmitReconBuffer(rbuf, 0, 0);
Dprintf1("RECON: submitblocked=%d\n", submitblocked);
if (!submitblocked) retcode = IssueNextReadRequest(raidPtr, frow, event->col);
break;
/* a write I/O has completed */
case RF_REVENT_WRITEDONE:
if (rf_floatingRbufDebug) {
rf_CheckFloatingRbufCount(raidPtr, 1);
}
sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU;
rbuf = (RF_ReconBuffer_t *) event->arg;
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
Dprintf3("RECON: WRITEDONE EVENT: psid %d ru %d (%d %% complete)\n",
rbuf->parityStripeID, rbuf->which_ru, raidPtr->reconControl[frow]->percentComplete);
rf_ReconMapUpdate(raidPtr, raidPtr->reconControl[frow]->reconMap,
rbuf->failedDiskSectorOffset, rbuf->failedDiskSectorOffset + sectorsPerRU -1);
rf_RemoveFromActiveReconTable(raidPtr, frow, rbuf->parityStripeID, rbuf->which_ru);
if (rbuf->type == RF_RBUF_TYPE_FLOATING) {
RF_LOCK_MUTEX(raidPtr->reconControl[frow]->rb_mutex);
raidPtr->numFullReconBuffers--;
rf_ReleaseFloatingReconBuffer(raidPtr, frow, rbuf);
RF_UNLOCK_MUTEX(raidPtr->reconControl[frow]->rb_mutex);
} else if (rbuf->type == RF_RBUF_TYPE_FORCED) rf_FreeReconBuffer(rbuf);
else RF_ASSERT(0);
break;
case RF_REVENT_BUFCLEAR: /* A buffer-stall condition has been cleared */
Dprintf2("RECON: BUFCLEAR EVENT: row %d col %d\n",frow, event->col);
submitblocked = rf_SubmitReconBuffer(raidPtr->reconControl[frow]->perDiskInfo[event->col].rbuf, 0, (int) (long)event->arg);
RF_ASSERT(!submitblocked); /* we wouldn't have gotten the BUFCLEAR event if we couldn't submit */
retcode = IssueNextReadRequest(raidPtr, frow, event->col);
break;
case RF_REVENT_BLOCKCLEAR: /* A user-write reconstruction blockage has been cleared */
DDprintf2("RECON: BLOCKCLEAR EVENT: row %d col %d\n",frow, event->col);
retcode = TryToRead(raidPtr, frow, event->col);
break;
case RF_REVENT_HEADSEPCLEAR: /* A max-head-separation reconstruction blockage has been cleared */
Dprintf2("RECON: HEADSEPCLEAR EVENT: row %d col %d\n",frow, event->col);
retcode = TryToRead(raidPtr, frow, event->col);
break;
/* a buffer has become ready to write */
case RF_REVENT_BUFREADY:
Dprintf2("RECON: BUFREADY EVENT: row %d col %d\n",frow, event->col);
retcode = IssueNextWriteRequest(raidPtr, frow);
if (rf_floatingRbufDebug) {
rf_CheckFloatingRbufCount(raidPtr, 1);
}
break;
/* we need to skip the current RU entirely because it got recon'd while we were waiting for something else to happen */
case RF_REVENT_SKIP:
DDprintf2("RECON: SKIP EVENT: row %d col %d\n",frow, event->col);
retcode = IssueNextReadRequest(raidPtr, frow, event->col);
break;
/* a forced-reconstruction read access has completed. Just submit the buffer */
case RF_REVENT_FORCEDREADDONE:
rbuf = (RF_ReconBuffer_t *) event->arg;
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
DDprintf2("RECON: FORCEDREADDONE EVENT: row %d col %d\n",frow, event->col);
submitblocked = rf_SubmitReconBuffer(rbuf, 1, 0);
RF_ASSERT(!submitblocked);
break;
default:
RF_PANIC();
}
rf_FreeReconEventDesc(event);
return(retcode);
}
/*****************************************************************************************
*
* find the next thing that's needed on the indicated disk, and issue a read
* request for it. We assume that the reconstruction buffer associated with this
* process is free to receive the data. If reconstruction is blocked on the
* indicated RU, we issue a blockage-release request instead of a physical disk
* read request. If the current disk gets too far ahead of the others, we issue
* a head-separation wait request and return.
*
* ctrl->{ru_count, curPSID, diskOffset} and rbuf->failedDiskSectorOffset are
* maintained to point the the unit we're currently accessing. Note that this deviates
* from the standard C idiom of having counters point to the next thing to be
* accessed. This allows us to easily retry when we're blocked by head separation
* or reconstruction-blockage events.
*
* returns nonzero if and only if there is nothing left unread on the indicated disk
****************************************************************************************/
static int IssueNextReadRequest(raidPtr, row, col)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_RowCol_t col;
{
RF_PerDiskReconCtrl_t *ctrl = &raidPtr->reconControl[row]->perDiskInfo[col];
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_ReconBuffer_t *rbuf = ctrl->rbuf;
RF_ReconUnitCount_t RUsPerPU = layoutPtr->SUsPerPU / layoutPtr->SUsPerRU;
RF_SectorCount_t sectorsPerRU = layoutPtr->sectorsPerStripeUnit * layoutPtr->SUsPerRU;
int do_new_check = 0, retcode = 0, status;
/* if we are currently the slowest disk, mark that we have to do a new check */
if (ctrl->headSepCounter <= raidPtr->reconControl[row]->minHeadSepCounter) do_new_check = 1;
while (1) {
ctrl->ru_count++;
if (ctrl->ru_count < RUsPerPU) {
ctrl->diskOffset += sectorsPerRU;
rbuf->failedDiskSectorOffset += sectorsPerRU;
} else {
ctrl->curPSID++;
ctrl->ru_count = 0;
/* code left over from when head-sep was based on parity stripe id */
if (ctrl->curPSID >= raidPtr->reconControl[row]->lastPSID) {
CheckForNewMinHeadSep(raidPtr, row, ++(ctrl->headSepCounter));
return(1); /* finito! */
}
/* find the disk offsets of the start of the parity stripe on both the current disk and the failed disk.
* skip this entire parity stripe if either disk does not appear in the indicated PS
*/
status = ComputePSDiskOffsets(raidPtr, ctrl->curPSID, row, col, &ctrl->diskOffset, &rbuf->failedDiskSectorOffset,
&rbuf->spRow, &rbuf->spCol, &rbuf->spOffset);
if (status) {
ctrl->ru_count = RUsPerPU-1; continue;
}
}
rbuf->which_ru = ctrl->ru_count;
/* skip this RU if it's already been reconstructed */
if (rf_CheckRUReconstructed(raidPtr->reconControl[row]->reconMap, rbuf->failedDiskSectorOffset)) {
Dprintf2("Skipping psid %ld ru %d: already reconstructed\n",ctrl->curPSID,ctrl->ru_count);
continue;
}
break;
}
ctrl->headSepCounter++;
if (do_new_check) CheckForNewMinHeadSep(raidPtr, row, ctrl->headSepCounter); /* update min if needed */
/* at this point, we have definitely decided what to do, and we have only to see if we can actually do it now */
rbuf->parityStripeID = ctrl->curPSID;
rbuf->which_ru = ctrl->ru_count;
bzero((char *)&raidPtr->recon_tracerecs[col], sizeof(raidPtr->recon_tracerecs[col]));
raidPtr->recon_tracerecs[col].reconacc = 1;
RF_ETIMER_START(raidPtr->recon_tracerecs[col].recon_timer);
retcode = TryToRead(raidPtr, row, col);
return(retcode);
}
/* tries to issue the next read on the indicated disk. We may be blocked by (a) the heads being too
* far apart, or (b) recon on the indicated RU being blocked due to a write by a user thread.
* In this case, we issue a head-sep or blockage wait request, which will cause this same routine
* to be invoked again later when the blockage has cleared.
*/
static int TryToRead(raidPtr, row, col)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_RowCol_t col;
{
RF_PerDiskReconCtrl_t *ctrl = &raidPtr->reconControl[row]->perDiskInfo[col];
RF_SectorCount_t sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU;
RF_StripeNum_t psid = ctrl->curPSID;
RF_ReconUnitNum_t which_ru = ctrl->ru_count;
RF_DiskQueueData_t *req;
int status, created = 0;
RF_ReconParityStripeStatus_t *pssPtr;
/* if the current disk is too far ahead of the others, issue a head-separation wait and return */
if (CheckHeadSeparation(raidPtr, ctrl, row, col, ctrl->headSepCounter, which_ru)) return(0);
RF_LOCK_PSS_MUTEX(raidPtr, row, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl[row]->pssTable, psid, which_ru, RF_PSS_CREATE, &created);
/* if recon is blocked on the indicated parity stripe, issue a block-wait request and return.
* this also must mark the indicated RU in the stripe as under reconstruction if not blocked.
*/
status = CheckForcedOrBlockedReconstruction(raidPtr, pssPtr, ctrl, row, col, psid, which_ru);
if (status == RF_PSS_RECON_BLOCKED) {
Dprintf2("RECON: Stalling psid %ld ru %d: recon blocked\n",psid,which_ru);
goto out;
} else if (status == RF_PSS_FORCED_ON_WRITE) {
rf_CauseReconEvent(raidPtr, row, col, NULL, RF_REVENT_SKIP);
goto out;
}
/* make one last check to be sure that the indicated RU didn't get reconstructed while
* we were waiting for something else to happen. This is unfortunate in that it causes
* us to make this check twice in the normal case. Might want to make some attempt to
* re-work this so that we only do this check if we've definitely blocked on one of the
* above checks. When this condition is detected, we may have just created a bogus
* status entry, which we need to delete.
*/
if (rf_CheckRUReconstructed(raidPtr->reconControl[row]->reconMap, ctrl->rbuf->failedDiskSectorOffset)) {
Dprintf2("RECON: Skipping psid %ld ru %d: prior recon after stall\n",psid,which_ru);
if (created) rf_PSStatusDelete(raidPtr, raidPtr->reconControl[row]->pssTable, pssPtr);
rf_CauseReconEvent(raidPtr, row, col, NULL, RF_REVENT_SKIP);
goto out;
}
/* found something to read. issue the I/O */
Dprintf5("RECON: Read for psid %ld on row %d col %d offset %ld buf %lx\n",
psid, row, col, ctrl->diskOffset, ctrl->rbuf->buffer);
RF_ETIMER_STOP(raidPtr->recon_tracerecs[col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[col].recon_timer);
raidPtr->recon_tracerecs[col].specific.recon.recon_start_to_fetch_us =
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[col].recon_timer);
/* should be ok to use a NULL proc pointer here, all the bufs we use should be in kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_READ, ctrl->diskOffset, sectorsPerRU, ctrl->rbuf->buffer, psid, which_ru,
ReconReadDoneProc, (void *) ctrl, NULL, &raidPtr->recon_tracerecs[col], (void *)raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this -- XXX */
ctrl->rbuf->arg = (void *) req;
rf_DiskIOEnqueue(&raidPtr->Queues[row][col], req, RF_IO_RECON_PRIORITY);
pssPtr->issued[col] = 1;
out:
RF_UNLOCK_PSS_MUTEX(raidPtr, row, psid);
return(0);
}
/* given a parity stripe ID, we want to find out whether both the current disk and the
* failed disk exist in that parity stripe. If not, we want to skip this whole PS.
* If so, we want to find the disk offset of the start of the PS on both the current
* disk and the failed disk.
*
* this works by getting a list of disks comprising the indicated parity stripe, and
* searching the list for the current and failed disks. Once we've decided they both
* exist in the parity stripe, we need to decide whether each is data or parity,
* so that we'll know which mapping function to call to get the corresponding disk
* offsets.
*
* this is kind of unpleasant, but doing it this way allows the reconstruction code
* to use parity stripe IDs rather than physical disks address to march through the
* failed disk, which greatly simplifies a lot of code, as well as eliminating the
* need for a reverse-mapping function. I also think it will execute faster, since
* the calls to the mapping module are kept to a minimum.
*
* ASSUMES THAT THE STRIPE IDENTIFIER IDENTIFIES THE DISKS COMPRISING THE STRIPE
* IN THE CORRECT ORDER
*/
static int ComputePSDiskOffsets(
RF_Raid_t *raidPtr, /* raid descriptor */
RF_StripeNum_t psid, /* parity stripe identifier */
RF_RowCol_t row, /* row and column of disk to find the offsets for */
RF_RowCol_t col,
RF_SectorNum_t *outDiskOffset,
RF_SectorNum_t *outFailedDiskSectorOffset,
RF_RowCol_t *spRow, /* OUT: row,col of spare unit for failed unit */
RF_RowCol_t *spCol,
RF_SectorNum_t *spOffset) /* OUT: offset into disk containing spare unit */
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_RowCol_t fcol = raidPtr->reconControl[row]->fcol;
RF_RaidAddr_t sosRaidAddress; /* start-of-stripe */
RF_RowCol_t *diskids;
u_int i, j, k, i_offset, j_offset;
RF_RowCol_t prow, pcol;
int testcol, testrow;
RF_RowCol_t stripe;
RF_SectorNum_t poffset;
char i_is_parity=0, j_is_parity=0;
RF_RowCol_t stripeWidth = layoutPtr->numDataCol + layoutPtr->numParityCol;
/* get a listing of the disks comprising that stripe */
sosRaidAddress = rf_ParityStripeIDToRaidAddress(layoutPtr, psid);
(layoutPtr->map->IdentifyStripe)(raidPtr, sosRaidAddress, &diskids, &stripe);
RF_ASSERT(diskids);
/* reject this entire parity stripe if it does not contain the indicated disk or it does not contain the failed disk */
if (row != stripe)
goto skipit;
for (i=0; i<stripeWidth; i++) {
if (col == diskids[i])
break;
}
if (i == stripeWidth)
goto skipit;
for (j=0; j<stripeWidth; j++) {
if (fcol == diskids[j])
break;
}
if (j == stripeWidth) {
goto skipit;
}
/* find out which disk the parity is on */
(layoutPtr->map->MapParity)(raidPtr, sosRaidAddress, &prow, &pcol, &poffset, RF_DONT_REMAP);
/* find out if either the current RU or the failed RU is parity */
/* also, if the parity occurs in this stripe prior to the data and/or failed col, we need to decrement i and/or j */
for (k=0; k<stripeWidth; k++)
if (diskids[k] == pcol)
break;
RF_ASSERT(k < stripeWidth);
i_offset = i; j_offset=j;
if (k < i) i_offset--; else if (k==i) {i_is_parity = 1; i_offset = 0;} /* set offsets to zero to disable multiply below */
if (k < j) j_offset--; else if (k==j) {j_is_parity = 1; j_offset = 0;}
/* at this point, [ij]_is_parity tells us whether the [current,failed] disk is parity at
* the start of this RU, and, if data, "[ij]_offset" tells us how far into the stripe
* the [current,failed] disk is.
*/
/* call the mapping routine to get the offset into the current disk, repeat for failed disk. */
if (i_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + i_offset * layoutPtr->sectorsPerStripeUnit, &testrow, &testcol, outDiskOffset, RF_DONT_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + i_offset * layoutPtr->sectorsPerStripeUnit, &testrow, &testcol, outDiskOffset, RF_DONT_REMAP);
RF_ASSERT(row == testrow && col == testcol);
if (j_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, &testrow, &testcol, outFailedDiskSectorOffset, RF_DONT_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, &testrow, &testcol, outFailedDiskSectorOffset, RF_DONT_REMAP);
RF_ASSERT(row == testrow && fcol == testcol);
/* now locate the spare unit for the failed unit */
if (layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) {
if (j_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, spRow, spCol, spOffset, RF_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, spRow, spCol, spOffset, RF_REMAP);
} else {
*spRow = raidPtr->reconControl[row]->spareRow;
*spCol = raidPtr->reconControl[row]->spareCol;
*spOffset = *outFailedDiskSectorOffset;
}
return(0);
skipit:
Dprintf3("RECON: Skipping psid %ld: nothing needed from r%d c%d\n",
psid, row, col);
return(1);
}
/* this is called when a buffer has become ready to write to the replacement disk */
static int IssueNextWriteRequest(raidPtr, row)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_SectorCount_t sectorsPerRU = layoutPtr->sectorsPerStripeUnit * layoutPtr->SUsPerRU;
RF_RowCol_t fcol = raidPtr->reconControl[row]->fcol;
RF_ReconBuffer_t *rbuf;
RF_DiskQueueData_t *req;
rbuf = rf_GetFullReconBuffer(raidPtr->reconControl[row]);
RF_ASSERT(rbuf); /* there must be one available, or we wouldn't have gotten the event that sent us here */
RF_ASSERT(rbuf->pssPtr);
rbuf->pssPtr->writeRbuf = rbuf;
rbuf->pssPtr = NULL;
Dprintf7("RECON: New write (r %d c %d offs %d) for psid %ld ru %d (failed disk offset %ld) buf %lx\n",
rbuf->spRow, rbuf->spCol, rbuf->spOffset, rbuf->parityStripeID,
rbuf->which_ru, rbuf->failedDiskSectorOffset, rbuf->buffer);
Dprintf6("RECON: new write psid %ld %02x %02x %02x %02x %02x\n",
rbuf->parityStripeID, rbuf->buffer[0]&0xff, rbuf->buffer[1]&0xff,
rbuf->buffer[2]&0xff, rbuf->buffer[3]&0xff, rbuf->buffer[4]&0xff);
/* should be ok to use a NULL b_proc here b/c all addrs should be in kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_WRITE, rbuf->spOffset,
sectorsPerRU, rbuf->buffer,
rbuf->parityStripeID, rbuf->which_ru,
ReconWriteDoneProc, (void *) rbuf, NULL,
&raidPtr->recon_tracerecs[fcol],
(void *)raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this -- XXX */
rbuf->arg = (void *) req;
rf_DiskIOEnqueue(&raidPtr->Queues[rbuf->spRow][rbuf->spCol], req, RF_IO_RECON_PRIORITY);
return(0);
}
/* this gets called upon the completion of a reconstruction read operation
* the arg is a pointer to the per-disk reconstruction control structure
* for the process that just finished a read.
*
* called at interrupt context in the kernel, so don't do anything illegal here.
*/
static int ReconReadDoneProc(arg, status)
void *arg;
int status;
{
RF_PerDiskReconCtrl_t *ctrl = (RF_PerDiskReconCtrl_t *) arg;
RF_Raid_t *raidPtr = ctrl->reconCtrl->reconDesc->raidPtr;
if (status) {
/*
* XXX
*/
printf("Recon read failed!\n");
RF_PANIC();
}
RF_ETIMER_STOP(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
raidPtr->recon_tracerecs[ctrl->col].specific.recon.recon_fetch_to_return_us =
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
rf_CauseReconEvent(raidPtr, ctrl->row, ctrl->col, NULL, RF_REVENT_READDONE);
return(0);
}
/* this gets called upon the completion of a reconstruction write operation.
* the arg is a pointer to the rbuf that was just written
*
* called at interrupt context in the kernel, so don't do anything illegal here.
*/
static int ReconWriteDoneProc(arg, status)
void *arg;
int status;
{
RF_ReconBuffer_t *rbuf = (RF_ReconBuffer_t *) arg;
Dprintf2("Reconstruction completed on psid %ld ru %d\n",rbuf->parityStripeID, rbuf->which_ru);
if (status) {printf("Recon write failed!\n"); /*fprintf(stderr,"Recon write failed!\n");*/ RF_PANIC();}
rf_CauseReconEvent((RF_Raid_t *) rbuf->raidPtr, rbuf->row, rbuf->col, arg, RF_REVENT_WRITEDONE);
return(0);
}
/* computes a new minimum head sep, and wakes up anyone who needs to be woken as a result */
static void CheckForNewMinHeadSep(raidPtr, row, hsCtr)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_HeadSepLimit_t hsCtr;
{
RF_ReconCtrl_t *reconCtrlPtr = raidPtr->reconControl[row];
RF_HeadSepLimit_t new_min;
RF_RowCol_t i;
RF_CallbackDesc_t *p;
RF_ASSERT(hsCtr >= reconCtrlPtr->minHeadSepCounter); /* from the definition of a minimum */
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
new_min = ~ (1L<< (8*sizeof(long)-1)); /* 0x7FFF....FFF */
for (i=0; i<raidPtr->numCol; i++) if (i != reconCtrlPtr->fcol) {
if (reconCtrlPtr->perDiskInfo[i].headSepCounter < new_min) new_min = reconCtrlPtr->perDiskInfo[i].headSepCounter;
}
/* set the new minimum and wake up anyone who can now run again */
if (new_min != reconCtrlPtr->minHeadSepCounter) {
reconCtrlPtr->minHeadSepCounter = new_min;
Dprintf1("RECON: new min head pos counter val is %ld\n",new_min);
while (reconCtrlPtr->headSepCBList) {
if (reconCtrlPtr->headSepCBList->callbackArg.v > new_min) break;
p = reconCtrlPtr->headSepCBList;
reconCtrlPtr->headSepCBList = p->next;
p->next = NULL;
rf_CauseReconEvent(raidPtr, p->row, p->col, NULL, RF_REVENT_HEADSEPCLEAR);
rf_FreeCallbackDesc(p);
}
}
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
}
/* checks to see that the maximum head separation will not be violated
* if we initiate a reconstruction I/O on the indicated disk. Limiting the
* maximum head separation between two disks eliminates the nasty buffer-stall
* conditions that occur when one disk races ahead of the others and consumes
* all of the floating recon buffers. This code is complex and unpleasant
* but it's necessary to avoid some very nasty, albeit fairly rare,
* reconstruction behavior.
*
* returns non-zero if and only if we have to stop working on the indicated disk
* due to a head-separation delay.
*/
static int CheckHeadSeparation(
RF_Raid_t *raidPtr,
RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t row,
RF_RowCol_t col,
RF_HeadSepLimit_t hsCtr,
RF_ReconUnitNum_t which_ru)
{
RF_ReconCtrl_t *reconCtrlPtr = raidPtr->reconControl[row];
RF_CallbackDesc_t *cb, *p, *pt;
int retval = 0, tid;
/* if we're too far ahead of the slowest disk, stop working on this disk
* until the slower ones catch up. We do this by scheduling a wakeup callback
* for the time when the slowest disk has caught up. We define "caught up"
* with 20% hysteresis, i.e. the head separation must have fallen to at most
* 80% of the max allowable head separation before we'll wake up.
*
*/
rf_get_threadid(tid);
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
if ((raidPtr->headSepLimit >= 0) &&
((ctrl->headSepCounter - reconCtrlPtr->minHeadSepCounter) > raidPtr->headSepLimit))
{
Dprintf6("[%d] RECON: head sep stall: row %d col %d hsCtr %ld minHSCtr %ld limit %ld\n",
tid,row,col,ctrl->headSepCounter, reconCtrlPtr->minHeadSepCounter, raidPtr->headSepLimit);
cb = rf_AllocCallbackDesc();
/* the minHeadSepCounter value we have to get to before we'll wake up. build in 20% hysteresis. */
cb->callbackArg.v = (ctrl->headSepCounter - raidPtr->headSepLimit + raidPtr->headSepLimit/5);
cb->row = row; cb->col = col;
cb->next = NULL;
/* insert this callback descriptor into the sorted list of pending head-sep callbacks */
p = reconCtrlPtr->headSepCBList;
if (!p) reconCtrlPtr->headSepCBList = cb;
else if (cb->callbackArg.v < p->callbackArg.v) {
cb->next = reconCtrlPtr->headSepCBList;
reconCtrlPtr->headSepCBList = cb;
}
else {
for (pt=p, p=p->next; p && (p->callbackArg.v < cb->callbackArg.v); pt=p,p=p->next);
cb->next = p;
pt->next = cb;
}
retval = 1;
#if RF_RECON_STATS > 0
ctrl->reconCtrl->reconDesc->hsStallCount++;
#endif /* RF_RECON_STATS > 0 */
}
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
return(retval);
}
/* checks to see if reconstruction has been either forced or blocked by a user operation.
* if forced, we skip this RU entirely.
* else if blocked, put ourselves on the wait list.
* else return 0.
*
* ASSUMES THE PSS MUTEX IS LOCKED UPON ENTRY
*/
static int CheckForcedOrBlockedReconstruction(
RF_Raid_t *raidPtr,
RF_ReconParityStripeStatus_t *pssPtr,
RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t row,
RF_RowCol_t col,
RF_StripeNum_t psid,
RF_ReconUnitNum_t which_ru)
{
RF_CallbackDesc_t *cb;
int retcode = 0;
if ((pssPtr->flags & RF_PSS_FORCED_ON_READ) || (pssPtr->flags & RF_PSS_FORCED_ON_WRITE)) retcode = RF_PSS_FORCED_ON_WRITE;
else if (pssPtr->flags & RF_PSS_RECON_BLOCKED) {
Dprintf4("RECON: row %d col %d blocked at psid %ld ru %d\n",row, col, psid, which_ru);
cb = rf_AllocCallbackDesc(); /* append ourselves to the blockage-wait list */
cb->row = row; cb->col = col;
cb->next = pssPtr->blockWaitList;
pssPtr->blockWaitList = cb;
retcode = RF_PSS_RECON_BLOCKED;
}
if (!retcode) pssPtr->flags |= RF_PSS_UNDER_RECON; /* mark this RU as under reconstruction */
return(retcode);
}
/* if reconstruction is currently ongoing for the indicated stripeID, reconstruction
* is forced to completion and we return non-zero to indicate that the caller must
* wait. If not, then reconstruction is blocked on the indicated stripe and the
* routine returns zero. If and only if we return non-zero, we'll cause the cbFunc
* to get invoked with the cbArg when the reconstruction has completed.
*/
int rf_ForceOrBlockRecon(raidPtr, asmap, cbFunc, cbArg)
RF_Raid_t *raidPtr;
RF_AccessStripeMap_t *asmap;
void (*cbFunc)(RF_Raid_t *,void *);
void *cbArg;
{
RF_RowCol_t row = asmap->physInfo->row; /* which row of the array we're working on */
RF_StripeNum_t stripeID = asmap->stripeID; /* the stripe ID we're forcing recon on */
RF_SectorCount_t sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU; /* num sects in one RU */
RF_ReconParityStripeStatus_t *pssPtr; /* a pointer to the parity stripe status structure */
RF_StripeNum_t psid; /* parity stripe id */
RF_SectorNum_t offset, fd_offset; /* disk offset, failed-disk offset */
RF_RowCol_t *diskids;
RF_RowCol_t stripe;
int tid;
RF_ReconUnitNum_t which_ru; /* RU within parity stripe */
RF_RowCol_t fcol, diskno, i;
RF_ReconBuffer_t *new_rbuf; /* ptr to newly allocated rbufs */
RF_DiskQueueData_t *req; /* disk I/O req to be enqueued */
RF_CallbackDesc_t *cb;
int created = 0, nPromoted;
rf_get_threadid(tid);
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);
RF_LOCK_PSS_MUTEX(raidPtr, row, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl[row]->pssTable, psid, which_ru, RF_PSS_CREATE|RF_PSS_RECON_BLOCKED, &created);
/* if recon is not ongoing on this PS, just return */
if (!(pssPtr->flags & RF_PSS_UNDER_RECON)) {
RF_UNLOCK_PSS_MUTEX(raidPtr, row, psid);
return(0);
}
/* otherwise, we have to wait for reconstruction to complete on this RU. */
/* In order to avoid waiting for a potentially large number of low-priority accesses to
* complete, we force a normal-priority (i.e. not low-priority) reconstruction
* on this RU.
*/
if (!(pssPtr->flags & RF_PSS_FORCED_ON_WRITE) && !(pssPtr->flags & RF_PSS_FORCED_ON_READ)) {
DDprintf1("Forcing recon on psid %ld\n",psid);
pssPtr->flags |= RF_PSS_FORCED_ON_WRITE; /* mark this RU as under forced recon */
pssPtr->flags &= ~RF_PSS_RECON_BLOCKED; /* clear the blockage that we just set */
fcol = raidPtr->reconControl[row]->fcol;
/* get a listing of the disks comprising the indicated stripe */
(raidPtr->Layout.map->IdentifyStripe)(raidPtr, asmap->raidAddress, &diskids, &stripe);
RF_ASSERT(row == stripe);
/* For previously issued reads, elevate them to normal priority. If the I/O has already completed,
* it won't be found in the queue, and hence this will be a no-op.
* For unissued reads, allocate buffers and issue new reads. The fact that we've set the
* FORCED bit means that the regular recon procs will not re-issue these reqs
*/
for (i=0; i<raidPtr->Layout.numDataCol+raidPtr->Layout.numParityCol; i++) if ( (diskno = diskids[i]) != fcol) {
if (pssPtr->issued[diskno]) {
nPromoted = rf_DiskIOPromote(&raidPtr->Queues[row][diskno], psid, which_ru);
if (rf_reconDebug && nPromoted) printf("[%d] promoted read from row %d col %d\n",tid,row,diskno);
} else {
new_rbuf = rf_MakeReconBuffer(raidPtr, row, diskno, RF_RBUF_TYPE_FORCED); /* create new buf */
ComputePSDiskOffsets(raidPtr, psid, row, diskno, &offset, &fd_offset,
&new_rbuf->spRow, &new_rbuf->spCol, &new_rbuf->spOffset); /* find offsets & spare location */
new_rbuf->parityStripeID = psid; /* fill in the buffer */
new_rbuf->which_ru = which_ru;
new_rbuf->failedDiskSectorOffset = fd_offset;
new_rbuf->priority = RF_IO_NORMAL_PRIORITY;
/* use NULL b_proc b/c all addrs should be in kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_READ, offset + which_ru * sectorsPerRU, sectorsPerRU, new_rbuf->buffer,
psid, which_ru, (int (*)(void *, int))ForceReconReadDoneProc, (void *) new_rbuf, NULL,
NULL,(void *)raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this -- XXX */
new_rbuf->arg = req;
rf_DiskIOEnqueue(&raidPtr->Queues[row][diskno], req, RF_IO_NORMAL_PRIORITY); /* enqueue the I/O */
Dprintf3("[%d] Issued new read req on row %d col %d\n",tid,row,diskno);
}
}
/* if the write is sitting in the disk queue, elevate its priority */
if (rf_DiskIOPromote(&raidPtr->Queues[row][fcol], psid, which_ru)) printf("[%d] promoted write to row %d col %d\n",tid,row,fcol);
}
/* install a callback descriptor to be invoked when recon completes on this parity stripe. */
cb = rf_AllocCallbackDesc();
/* XXX the following is bogus.. These functions don't really match!! GO */
cb->callbackFunc = (void (*)(RF_CBParam_t))cbFunc;
cb->callbackArg.p = (void *) cbArg;
cb->next = pssPtr->procWaitList;
pssPtr->procWaitList = cb;
DDprintf2("[%d] Waiting for forced recon on psid %ld\n",tid,psid);
RF_UNLOCK_PSS_MUTEX(raidPtr, row, psid);
return(1);
}
/* called upon the completion of a forced reconstruction read.
* all we do is schedule the FORCEDREADONE event.
* called at interrupt context in the kernel, so don't do anything illegal here.
*/
static void ForceReconReadDoneProc(arg, status)
void *arg;
int status;
{
RF_ReconBuffer_t *rbuf = arg;
if (status) {printf("Forced recon read failed!\n"); /*fprintf(stderr,"Forced recon read failed!\n");*/ RF_PANIC();}
rf_CauseReconEvent((RF_Raid_t *) rbuf->raidPtr, rbuf->row, rbuf->col, (void *) rbuf, RF_REVENT_FORCEDREADDONE);
}
/* releases a block on the reconstruction of the indicated stripe */
int rf_UnblockRecon(raidPtr, asmap)
RF_Raid_t *raidPtr;
RF_AccessStripeMap_t *asmap;
{
RF_RowCol_t row = asmap->origRow;
RF_StripeNum_t stripeID = asmap->stripeID;
RF_ReconParityStripeStatus_t *pssPtr;
RF_ReconUnitNum_t which_ru;
RF_StripeNum_t psid;
int tid, created = 0;
RF_CallbackDesc_t *cb;
rf_get_threadid(tid);
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);
RF_LOCK_PSS_MUTEX( raidPtr, row, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl[row]->pssTable, psid, which_ru, RF_PSS_NONE, &created);
/* When recon is forced, the pss desc can get deleted before we get back to unblock recon.
* But, this can _only_ happen when recon is forced.
* It would be good to put some kind of sanity check here, but how to decide if recon
* was just forced or not?
*/
if (!pssPtr) {
/*printf("Warning: no pss descriptor upon unblock on psid %ld RU %d\n",psid,which_ru);*/
if (rf_reconDebug || rf_pssDebug) printf("Warning: no pss descriptor upon unblock on psid %ld RU %d\n",(long)psid,which_ru);
goto out;
}
pssPtr->blockCount--;
Dprintf3("[%d] unblocking recon on psid %ld: blockcount is %d\n",tid,psid,pssPtr->blockCount);
if (pssPtr->blockCount == 0) { /* if recon blockage has been released */
/* unblock recon before calling CauseReconEvent in case CauseReconEvent causes us to
* try to issue a new read before returning here.
*/
pssPtr->flags &= ~RF_PSS_RECON_BLOCKED;
while (pssPtr->blockWaitList) { /* spin through the block-wait list and release all the waiters */
cb = pssPtr->blockWaitList;
pssPtr->blockWaitList = cb->next;
cb->next = NULL;
rf_CauseReconEvent(raidPtr, cb->row, cb->col, NULL, RF_REVENT_BLOCKCLEAR);
rf_FreeCallbackDesc(cb);
}
if (!(pssPtr->flags & RF_PSS_UNDER_RECON)) { /* if no recon was requested while recon was blocked */
rf_PSStatusDelete(raidPtr, raidPtr->reconControl[row]->pssTable, pssPtr);
}
}
out:
RF_UNLOCK_PSS_MUTEX( raidPtr, row, psid );
return(0);
}
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