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#include "logfsos.h"
#include "logfs.h"
#include "local.h"
#include "fcall.h"
static char *
copypages(LogfsServer *server, long newb, long oldb, Pageset copymask, LogfsLowLevelReadResult *llrrp, int *markedbadp)
{
char *errmsg;
int page;
LogfsLowLevel *ll;
int ppb;
int pagesize;
uchar *buf;
if(copymask == 0)
return nil;
ll = server->ll;
ppb = 1 << ll->l2pagesperblock;
pagesize = 1 << ll->l2pagesize;
*markedbadp = 0;
*llrrp = LogfsLowLevelReadResultOk;
errmsg = nil;
buf = logfsrealloc(nil, 1 << ll->l2pagesize);
if(buf == nil)
return Enomem;
for(page = ppb - 1; page >= 0; page--) {
Pageset m;
m = logfsdatapagemask(1, page);
if(copymask & m) {
LogfsLowLevelReadResult llrr;
if(server->trace > 1)
print("copypages read page %d\n", page);
errmsg = (*ll->readpagerange)(ll, buf, oldb, page, 0, pagesize, &llrr);
if(errmsg != nil)
break;
if(llrr > *llrrp)
*llrrp = llrr;
if(server->trace > 1)
print("copypages write page %d\n", page);
errmsg = (*ll->writepage)(ll, buf, newb, page);
if(errmsg) {
if(strcmp(errmsg, Eio) == 0) {
(*ll->markblockbad)(ll, newb);
*markedbadp = 1;
}
break;
}
if(server->trace > 1)
print("copypages end page %d\n", page);
}
}
logfsfreemem(buf);
return errmsg;
}
char *
logfsservercopyactivedata(LogfsServer *server, long newb, long oldblockindex, int forcepage0, LogfsLowLevelReadResult *llrrp, int *markedbadp)
{
LogfsLowLevel *ll = server->ll;
ulong newpath;
DataBlock *ob;
char *errmsg;
Pageset copymask;
ob = server->datablock + oldblockindex;
copymask = ~ob->free;
if(forcepage0)
copymask |= logfsdatapagemask(1, 0);
if(server->trace > 1)
print("copyactivedata %ld: (%ld -> %ld)\n", oldblockindex, ob->block, newb);
newpath = mkdatapath(dataseqof(ob->path), copygensucc(copygenof(ob->path)));
(*ll->setblocktag)(ll, newb, LogfsTdata);
(*ll->setblockpath)(ll, newb, newpath);
errmsg = copypages(server, newb, ob->block, copymask, llrrp, markedbadp);
if(errmsg)
return errmsg;
/*
* anything not copied is now not dirty
*/
ob->dirty &= copymask;
ob->block = newb;
ob->path = newpath;
return nil;
}
/*
* unconditionally replace a datablock, and mark the old one bad
* NB: if page 0 is apparently unused, force it to be copied, and mark
* it free and dirty afterwards
*/
char *
logfsserverreplacedatablock(LogfsServer *server, long index)
{
long newb;
LogfsLowLevel *ll = server->ll;
newb = logfsfindfreeblock(ll, AllocReasonReplace);
/* TODO - recover space by scavenging other blocks, or recycling the log */
while(newb >= 0) {
char *errmsg;
LogfsLowLevelReadResult llrr;
long oldblock;
int markedbad;
DataBlock *db;
db = server->datablock + index;
oldblock = db->block;
errmsg = logfsservercopyactivedata(server, newb, index, 1, &llrr, &markedbad);
if(errmsg) {
if(!markedbad)
return errmsg;
newb = logfsfindfreeblock(ll, AllocReasonReplace);
continue;
}
(*ll->markblockbad)(ll, oldblock);
return nil;
}
return logfsefullreplacing;
}
char *
logfsserverreplacelogblock(LogfsServer *server, LogSegment *seg, long index)
{
ulong opath;
LogfsLowLevel *ll = server->ll;
long oldb = seg->blockmap[index];
opath = (*ll->getblockpath)(ll, oldb);
for(;;) {
long newb;
int pages;
char *errmsg;
LogfsLowLevelReadResult llrr;
int markedbad;
newb = logfsfindfreeblock(ll, AllocReasonReplace);
if(newb < 0)
return "full replacing log block";
/* TODO - scavenge data space for a spare block */
(*ll->setblocktag)(ll, newb, LogfsTlog);
(*ll->setblockpath)(ll, newb, mklogpath(seg->gen, index, copygensucc(copygenof(opath))));
if(index == seg->curblockindex)
pages = seg->curpage;
else
pages = 1 << server->ll->l2pagesperblock;
errmsg = copypages(server, newb, oldb, logfsdatapagemask(pages, 0), &llrr, &markedbad);
if(errmsg == nil) {
(*ll->markblockbad)(ll, seg->blockmap[index]);
seg->blockmap[index] = newb;
return nil;
}
if(!markedbad)
return errmsg;
}
}
char *
logfsserverreplaceblock(LogfsServer *server, LogSegment *seg, long index)
{
if(seg)
return logfsserverreplacelogblock(server, seg, index);
else
return logfsserverreplacedatablock(server, index);
}
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