static void
superInit(char *label, u32int root, uchar score[VtScoreSize])
{
Super s;
memset(buf, 0, bsize);
memset(&s, 0, sizeof(s));
s.version = SuperVersion;
s.epochLow = 1;
s.epochHigh = 1;
s.qid = qid;
s.active = root;
s.next = NilBlock;
s.current = NilBlock;
strecpy(s.name, s.name+sizeof(s.name), label);
memmove(s.last, score, VtScoreSize);
superPack(&s, buf);
blockWrite(PartSuper, 0);
}
void
main(int argc, char **argv)
{
int fd;
Header h;
Super s;
ARGBEGIN{
default:
usage();
}ARGEND
if(argc == 0 || argc > 2)
usage();
if((fd = open(argv[0], argc==2 ? ORDWR : OREAD)) < 0)
sysfatal("open %s: %r", argv[0]);
if(pread(fd, buf, HeaderSize, HeaderOffset) != HeaderSize)
sysfatal("reading header: %r");
if(!headerUnpack(&h, buf))
sysfatal("unpacking header: %r");
if(pread(fd, buf, h.blockSize, (vlong)h.super*h.blockSize) != h.blockSize)
sysfatal("reading super block: %r");
if(!superUnpack(&s, buf))
sysfatal("unpacking super block: %r");
print("epoch %d\n", s.epochLow);
if(argc == 2){
s.epochLow = strtoul(argv[1], 0, 0);
superPack(&s, buf);
if(pwrite(fd, buf, h.blockSize, (vlong)h.super*h.blockSize) != h.blockSize)
sysfatal("writing super block: %r");
}
exits(0);
}
void
superWrite(Block* b, Super* super, int forceWrite)
{
superPack(super, b->data);
blockDirty(b);
if(forceWrite){
while(!blockWrite(b, Waitlock)){
/* this should no longer happen */
fprint(2, "%s: could not write super block; "
"waiting 10 seconds\n", argv0);
sleep(10*1000);
}
while(b->iostate != BioClean && b->iostate != BioDirty){
assert(b->iostate == BioWriting);
vtSleep(b->ioready);
}
/*
* it's okay that b might still be dirty.
* that means it got written out but with an old root pointer,
* but the other fields went out, and those are the ones
* we really care about. (specifically, epochHigh; see fsSnapshot).
*/
}
}
Fs *
fsOpen(char *file, VtSession *z, int32_t ncache, int mode)
{
int fd, m;
uint8_t oscore[VtScoreSize];
Block *b, *bs;
Disk *disk;
Fs *fs;
Super super;
switch(mode){
default:
vtSetError(EBadMode);
return nil;
case OReadOnly:
m = OREAD;
break;
case OReadWrite:
m = ORDWR;
break;
}
fd = open(file, m);
if(fd < 0){
vtSetError("open %s: %r", file);
return nil;
}
bwatchInit();
disk = diskAlloc(fd);
if(disk == nil){
vtSetError("diskAlloc: %R");
close(fd);
return nil;
}
fs = vtMemAllocZ(sizeof(Fs));
fs->mode = mode;
fs->name = vtStrDup(file);
fs->blockSize = diskBlockSize(disk);
fs->elk = vtLockAlloc();
fs->cache = cacheAlloc(disk, z, ncache, mode);
if(mode == OReadWrite && z)
fs->arch = archInit(fs->cache, disk, fs, z);
fs->z = z;
b = cacheLocal(fs->cache, PartSuper, 0, mode);
if(b == nil)
goto Err;
if(!superUnpack(&super, b->data)){
blockPut(b);
vtSetError("bad super block");
goto Err;
}
blockPut(b);
fs->ehi = super.epochHigh;
fs->elo = super.epochLow;
//fprint(2, "%s: fs->ehi %d fs->elo %d active=%d\n", argv0, fs->ehi, fs->elo, super.active);
fs->source = sourceRoot(fs, super.active, mode);
if(fs->source == nil){
/*
* Perhaps it failed because the block is copy-on-write.
* Do the copy and try again.
*/
if(mode == OReadOnly || strcmp(vtGetError(), EBadRoot) != 0)
goto Err;
b = cacheLocalData(fs->cache, super.active, BtDir, RootTag,
OReadWrite, 0);
if(b == nil){
vtSetError("cacheLocalData: %R");
goto Err;
}
if(b->l.epoch == fs->ehi){
blockPut(b);
vtSetError("bad root source block");
goto Err;
}
b = blockCopy(b, RootTag, fs->ehi, fs->elo);
if(b == nil)
goto Err;
localToGlobal(super.active, oscore);
super.active = b->addr;
bs = cacheLocal(fs->cache, PartSuper, 0, OReadWrite);
if(bs == nil){
blockPut(b);
vtSetError("cacheLocal: %R");
goto Err;
}
superPack(&super, bs->data);
blockDependency(bs, b, 0, oscore, nil);
blockPut(b);
blockDirty(bs);
blockRemoveLink(bs, globalToLocal(oscore), BtDir, RootTag, 0);
blockPut(bs);
fs->source = sourceRoot(fs, super.active, mode);
if(fs->source == nil){
vtSetError("sourceRoot: %R");
goto Err;
}
}
//fprint(2, "%s: got fs source\n", argv0);
vtRLock(fs->elk);
fs->file = fileRoot(fs->source);
fs->source->file = fs->file; /* point back */
vtRUnlock(fs->elk);
if(fs->file == nil){
vtSetError("fileRoot: %R");
goto Err;
}
//fprint(2, "%s: got file root\n", argv0);
if(mode == OReadWrite){
fs->metaFlush = periodicAlloc(fsMetaFlush, fs, 1000);
fs->snap = snapInit(fs);
}
return fs;
Err:
fprint(2, "%s: fsOpen error\n", argv0);
fsClose(fs);
return nil;
}
static void
archThread(void *v)
{
Arch *a = v;
Block *b;
Param p;
Super super;
int ret;
u32int addr;
uchar rbuf[VtRootSize];
VtRoot root;
vtThreadSetName("arch");
for(;;){
/* look for work */
vtLock(a->fs->elk);
b = superGet(a->c, &super);
if(b == nil){
vtUnlock(a->fs->elk);
fprint(2, "archThread: superGet: %R\n");
sleep(60*1000);
continue;
}
addr = super.next;
if(addr != NilBlock && super.current == NilBlock){
super.current = addr;
super.next = NilBlock;
superPack(&super, b->data);
blockDirty(b);
}else
addr = super.current;
blockPut(b);
vtUnlock(a->fs->elk);
if(addr == NilBlock){
/* wait for work */
vtLock(a->lk);
vtSleep(a->starve);
if(a->die != nil)
goto Done;
vtUnlock(a->lk);
continue;
}
sleep(10*1000); /* window of opportunity to provoke races */
/* do work */
memset(&p, 0, sizeof p);
p.blockSize = a->blockSize;
p.dsize = 3*VtEntrySize; /* root has three Entries */
p.c = a->c;
p.a = a;
ret = archWalk(&p, addr, BtDir, RootTag);
switch(ret){
default:
abort();
case ArchFailure:
fprint(2, "archiveBlock %#ux: %R\n", addr);
sleep(60*1000);
continue;
case ArchSuccess:
case ArchFaked:
break;
}
if(0) fprint(2, "archiveSnapshot 0x%#ux: maxdepth %ud nfixed %ud"
" send %ud nfailsend %ud nvisit %ud"
" nreclaim %ud nfake %ud nreal %ud\n",
addr, p.maxdepth, p.nfixed,
p.nsend, p.nfailsend, p.nvisit,
p.nreclaim, p.nfake, p.nreal);
if(0) fprint(2, "archiveBlock %V (%ud)\n", p.score, p.blockSize);
/* tie up vac root */
memset(&root, 0, sizeof root);
root.version = VtRootVersion;
strecpy(root.type, root.type+sizeof root.type, "vac");
strecpy(root.name, root.name+sizeof root.name, "fossil");
memmove(root.score, p.score, VtScoreSize);
memmove(root.prev, super.last, VtScoreSize);
root.blockSize = a->blockSize;
vtRootPack(&root, rbuf);
if(!vtWrite(a->z, p.score, VtRootType, rbuf, VtRootSize)
|| !vtSha1Check(p.score, rbuf, VtRootSize)){
fprint(2, "vtWriteBlock %#ux: %R\n", addr);
sleep(60*1000);
continue;
}
/* record success */
vtLock(a->fs->elk);
b = superGet(a->c, &super);
if(b == nil){
vtUnlock(a->fs->elk);
fprint(2, "archThread: superGet: %R\n");
sleep(60*1000);
continue;
}
super.current = NilBlock;
memmove(super.last, p.score, VtScoreSize);
superPack(&super, b->data);
blockDirty(b);
blockPut(b);
vtUnlock(a->fs->elk);
consPrint("archive vac:%V\n", p.score);
}
Done:
a->ref--;
vtWakeup(a->die);
vtUnlock(a->lk);
}
