/*
* Change the depth of the VtFile r.
* The entry e for r is contained in block p.
*/
static int
growdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
{
VtBlock *b, *bb;
assert(ISLOCKED(r));
assert(depth <= VtPointerDepth);
b = vtcacheglobal(r->c, e->score, e->type);
if(b == nil)
return -1;
/*
* Keep adding layers until we get to the right depth
* or an error occurs.
*/
while(DEPTH(e->type) < depth){
bb = vtcacheallocblock(r->c, e->type+1);
if(bb == nil)
break;
memmove(bb->data, b->score, VtScoreSize);
memmove(e->score, bb->score, VtScoreSize);
e->type++;
e->flags |= VtEntryLocal;
vtblockput(b);
b = bb;
}
vtentrypack(e, p->data, r->offset % r->epb);
vtblockput(b);
if(DEPTH(e->type) == depth)
return 0;
return -1;
}
static VtBlock *
blockwalk(VtBlock *p, int index, VtCache *c, int mode, VtEntry *e)
{
VtBlock *b;
int type;
uchar *score;
VtEntry oe;
switch(p->type){
case VtDataType:
assert(0);
case VtDirType:
type = e->type;
score = e->score;
break;
default:
type = p->type - 1;
score = p->data+index*VtScoreSize;
break;
}
/*print("walk from %V/%d ty %d to %V ty %d\n", p->score, index, p->type, score, type); */
if(mode == VtOWRITE && vtglobaltolocal(score) == NilBlock){
print("VtOWRITE && NilBlock\n");
b = vtcacheallocblock(c, type);
print("vtcachealloblcok returns %p\n", b);
if(b)
goto HaveCopy;
}else
b = vtcacheglobal(c, score, type);
if(b == nil || mode == VtOREAD)
return b;
if(vtglobaltolocal(b->score) != NilBlock)
return b;
oe = *e;
/*
* Copy on write.
*/
e->flags |= VtEntryLocal;
b = vtblockcopy(b/*, e->tag, fs->ehi, fs->elo*/);
if(b == nil)
return nil;
HaveCopy:
if(p->type == VtDirType){
memmove(e->score, b->score, VtScoreSize);
vtentrypack(e, p->data, index);
}else{
memmove(p->data+index*VtScoreSize, b->score, VtScoreSize);
}
return b;
}
void
threadmain(int argc, char **argv)
{
char *pref, *mountname, *mountplace;
uchar score[VtScoreSize], prev[VtScoreSize];
int i, fd, csize;
vlong bsize;
Tm tm;
VtEntry e;
VtBlock *b;
VtCache *c;
VtRoot root;
char *tmp, *tmpnam;
fmtinstall('F', vtfcallfmt);
fmtinstall('H', encodefmt);
fmtinstall('T', timefmt);
fmtinstall('V', vtscorefmt);
mountname = sysname();
mountplace = nil;
ARGBEGIN{
default:
usage();
break;
case 'D':
debug++;
break;
case 'V':
chattyventi = 1;
break;
case 'f':
fastwrites = 1;
break;
case 'i':
incremental = 1;
break;
case 'm':
mountname = EARGF(usage());
break;
case 'M':
mountplace = EARGF(usage());
i = strlen(mountplace);
if(i > 0 && mountplace[i-1] == '/')
mountplace[i-1] = 0;
break;
case 'n':
nop = 1;
break;
case 's':
statustime = atoi(EARGF(usage()));
break;
case 'v':
verbose = 1;
break;
case 'w':
nwritethread = atoi(EARGF(usage()));
break;
}ARGEND
if(argc != 1 && argc != 2)
usage();
if(statustime)
print("# %T vbackup %s %s\n", argv[0], argc>=2 ? argv[1] : "");
/*
* open fs
*/
if((disk = diskopenfile(argv[0])) == nil)
sysfatal("diskopen: %r");
if((disk = diskcache(disk, 32768, 2*MAXQ+16)) == nil)
sysfatal("diskcache: %r");
if((fsys = fsysopen(disk)) == nil)
sysfatal("fsysopen: %r");
/*
* connect to venti
*/
if((z = vtdial(nil)) == nil)
sysfatal("vtdial: %r");
if(vtconnect(z) < 0)
sysfatal("vtconnect: %r");
/*
* set up venti block cache
*/
zero = vtmallocz(fsys->blocksize);
bsize = fsys->blocksize;
csize = 50; /* plenty; could probably do with 5 */
if(verbose)
fprint(2, "cache %d blocks\n", csize);
c = vtcachealloc(z, bsize*csize);
zcache = c;
/*
* parse starting score
*/
memset(prev, 0, sizeof prev);
if(argc == 1){
vfile = vtfilecreateroot(c, (fsys->blocksize/VtScoreSize)*VtScoreSize,
fsys->blocksize, VtDataType);
if(vfile == nil)
sysfatal("vtfilecreateroot: %r");
vtfilelock(vfile, VtORDWR);
if(vtfilewrite(vfile, zero, 1, bsize*fsys->nblock-1) != 1)
sysfatal("vtfilewrite: %r");
if(vtfileflush(vfile) < 0)
sysfatal("vtfileflush: %r");
}else{
if(vtparsescore(argv[1], &pref, score) < 0)
sysfatal("bad score: %r");
if(pref!=nil && strcmp(pref, fsys->type) != 0)
sysfatal("score is %s but fsys is %s", pref, fsys->type);
b = vtcacheglobal(c, score, VtRootType, VtRootSize);
if(b){
if(vtrootunpack(&root, b->data) < 0)
sysfatal("bad root: %r");
if(strcmp(root.type, fsys->type) != 0)
sysfatal("root is %s but fsys is %s", root.type, fsys->type);
memmove(prev, score, VtScoreSize);
memmove(score, root.score, VtScoreSize);
vtblockput(b);
}
b = vtcacheglobal(c, score, VtDirType, VtEntrySize);
if(b == nil)
sysfatal("vtcacheglobal %V: %r", score);
if(vtentryunpack(&e, b->data, 0) < 0)
sysfatal("%V: vtentryunpack failed", score);
if(verbose)
fprint(2, "entry: size %llud psize %d dsize %d\n",
e.size, e.psize, e.dsize);
vtblockput(b);
if((vfile = vtfileopenroot(c, &e)) == nil)
sysfatal("vtfileopenroot: %r");
vtfilelock(vfile, VtORDWR);
if(e.dsize != bsize)
sysfatal("file system block sizes don't match %d %lld", e.dsize, bsize);
if(e.size != fsys->nblock*bsize)
sysfatal("file system block counts don't match %lld %lld", e.size, fsys->nblock*bsize);
}
tmpnam = nil;
if(incremental){
if(vtfilegetentry(vfile, &e) < 0)
sysfatal("vtfilegetentry: %r");
if((vscores = vtfileopenroot(c, &e)) == nil)
sysfatal("vtfileopenroot: %r");
vtfileunlock(vfile);
}else{
/*
* write scores of blocks into temporary file
*/
if((tmp = getenv("TMP")) != nil){
/* okay, good */
}else if(access("/var/tmp", 0) >= 0)
tmp = "/var/tmp";
else
tmp = "/tmp";
tmpnam = smprint("%s/vbackup.XXXXXX", tmp);
if(tmpnam == nil)
sysfatal("smprint: %r");
if((fd = opentemp(tmpnam, ORDWR|ORCLOSE)) < 0)
sysfatal("opentemp %s: %r", tmpnam);
if(statustime)
print("# %T reading scores into %s\n", tmpnam);
if(verbose)
fprint(2, "read scores into %s...\n", tmpnam);
Binit(&bscores, fd, OWRITE);
for(i=0; i<fsys->nblock; i++){
if(vtfileblockscore(vfile, i, score) < 0)
sysfatal("vtfileblockhash %d: %r", i);
if(Bwrite(&bscores, score, VtScoreSize) != VtScoreSize)
sysfatal("Bwrite: %r");
}
Bterm(&bscores);
vtfileunlock(vfile);
/*
* prep scores for rereading
*/
seek(fd, 0, 0);
Binit(&bscores, fd, OREAD);
}
/*
* start the main processes
*/
if(statustime)
print("# %T starting procs\n");
qcmp = qalloc();
qventi = qalloc();
rlock(&endlk);
proccreate(fsysproc, nil, STACK);
rlock(&endlk);
proccreate(ventiproc, nil, STACK);
rlock(&endlk);
proccreate(cmpproc, nil, STACK);
if(statustime){
rlock(&endlk);
proccreate(statusproc, nil, STACK);
}
/*
* wait for processes to finish
*/
wlock(&endlk);
qfree(qcmp);
qfree(qventi);
if(statustime)
print("# %T procs exited: %d of %d %d-byte blocks changed, "
"%d read, %d written, %d skipped, %d copied\n",
nchange, fsys->nblock, fsys->blocksize,
vtcachenread, vtcachenwrite, nskip, vtcachencopy);
/*
* prepare root block
*/
if(incremental)
vtfileclose(vscores);
vtfilelock(vfile, -1);
if(vtfileflush(vfile) < 0)
sysfatal("vtfileflush: %r");
if(vtfilegetentry(vfile, &e) < 0)
sysfatal("vtfilegetentry: %r");
vtfileunlock(vfile);
vtfileclose(vfile);
b = vtcacheallocblock(c, VtDirType, VtEntrySize);
if(b == nil)
sysfatal("vtcacheallocblock: %r");
vtentrypack(&e, b->data, 0);
if(vtblockwrite(b) < 0)
sysfatal("vtblockwrite: %r");
memset(&root, 0, sizeof root);
strecpy(root.name, root.name+sizeof root.name, argv[0]);
strecpy(root.type, root.type+sizeof root.type, fsys->type);
memmove(root.score, b->score, VtScoreSize);
root.blocksize = fsys->blocksize;
memmove(root.prev, prev, VtScoreSize);
vtblockput(b);
b = vtcacheallocblock(c, VtRootType, VtRootSize);
if(b == nil)
sysfatal("vtcacheallocblock: %r");
vtrootpack(&root, b->data);
if(vtblockwrite(b) < 0)
sysfatal("vtblockwrite: %r");
tm = *localtime(time(0));
tm.year += 1900;
tm.mon++;
if(mountplace == nil)
mountplace = guessmountplace(argv[0]);
print("mount /%s/%d/%02d%02d%s %s:%V %d/%02d%02d/%02d%02d\n",
mountname, tm.year, tm.mon, tm.mday,
mountplace,
root.type, b->score,
tm.year, tm.mon, tm.mday, tm.hour, tm.min);
print("# %T %s %s:%V\n", argv[0], root.type, b->score);
if(statustime)
print("# %T venti sync\n");
vtblockput(b);
if(vtsync(z) < 0)
sysfatal("vtsync: %r");
if(statustime)
print("# %T synced\n");
fsysclose(fsys);
diskclose(disk);
vtcachefree(zcache);
// Vtgoodbye hangs on Linux - not sure why.
// Probably vtfcallrpc doesn't quite get the
// remote hangup right. Also probably related
// to the vtrecvproc problem below.
// vtgoodbye(z);
// Leak here, because I can't seem to make
// the vtrecvproc exit.
// vtfreeconn(z);
free(tmpnam);
z = nil;
zcache = nil;
fsys = nil;
disk = nil;
threadexitsall(nil);
}
/*
* Retrieve the block containing the entry for r.
* If a snapshot has happened, we might need
* to get a new copy of the block. We avoid this
* in the common case by caching the score for
* the block and the last epoch in which it was valid.
*
* We use r->mode to tell the difference between active
* file system VtFiles (VtORDWR) and VtFiles for the
* snapshot file system (VtOREAD).
*/
static VtBlock*
fileloadblock(VtFile *r, int mode)
{
char e[ERRMAX];
u32int addr;
VtBlock *b;
switch(r->mode){
default:
assert(0);
case VtOWRITE:
assert(r->mode == VtORDWR);
if(r->local == 1){
b = vtcacheglobal(r->c, r->score, VtDirType);
if(b == nil)
return nil;
b->pc = getcallerpc(&r);
return b;
}
assert(r->parent != nil);
if(vtfilelock(r->parent, VtORDWR) < 0)
return nil;
b = vtfileblock(r->parent, r->offset/r->epb, VtORDWR);
if(b == nil)
b = vtfileblock(r->parent, r->offset/r->epb, VtOWRITE);
vtfileunlock(r->parent);
if(b == nil)
return nil;
memmove(r->score, b->score, VtScoreSize);
r->local = 1;
return b;
case VtORDWR:
assert(r->mode == VtORDWR);
if(r->local == 1){
b = vtcacheglobal(r->c, r->score, VtDirType);
if(b == nil)
return nil;
b->pc = getcallerpc(&r);
return b;
}
assert(r->parent != nil);
if(vtfilelock(r->parent, VtORDWR) < 0)
return nil;
b = vtfileblock(r->parent, r->offset/r->epb, VtORDWR);
vtfileunlock(r->parent);
if(b == nil)
return nil;
memmove(r->score, b->score, VtScoreSize);
r->local = 1;
return b;
case VtOREAD:
if(mode == VtORDWR){
werrstr("read/write lock of read-only file");
return nil;
}
addr = vtglobaltolocal(r->score);
if(addr == NilBlock)
return vtcacheglobal(r->c, r->score, VtDirType);
b = vtcachelocal(r->c, addr, VtDirType);
if(b)
return b;
/*
* If it failed because the epochs don't match, the block has been
* archived and reclaimed. Rewalk from the parent and get the
* new pointer. This can't happen in the VtORDWR case
* above because blocks in the current epoch don't get
* reclaimed. The fact that we're VtOREAD means we're
* a snapshot. (Or else the file system is read-only, but then
* the archiver isn't going around deleting blocks.)
*/
rerrstr(e, sizeof e);
if(strcmp(e, ELabelMismatch) == 0){
if(vtfilelock(r->parent, VtOREAD) < 0)
return nil;
b = vtfileblock(r->parent, r->offset/r->epb, VtOREAD);
vtfileunlock(r->parent);
if(b){
fprint(2, "vtfilealloc: lost %V found %V\n",
r->score, b->score);
memmove(r->score, b->score, VtScoreSize);
return b;
}
}
return nil;
}
}
static int
shrinkdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
{
VtBlock *b, *nb, *ob, *rb;
VtEntry oe;
assert(ISLOCKED(r));
assert(depth <= VtPointerDepth);
rb = vtcacheglobal(r->c, e->score, e->type);
if(rb == nil)
return -1;
/*
* Walk down to the new root block.
* We may stop early, but something is better than nothing.
*/
oe = *e;
ob = nil;
b = rb;
for(; DEPTH(e->type) > depth; e->type--){
nb = vtcacheglobal(r->c, b->data, e->type-1);
if(nb == nil)
break;
if(ob!=nil && ob!=rb)
vtblockput(ob);
ob = b;
b = nb;
}
if(b == rb){
vtblockput(rb);
return 0;
}
/*
* Right now, e points at the root block rb, b is the new root block,
* and ob points at b. To update:
*
* (i) change e to point at b
* (ii) zero the pointer ob -> b
* (iii) free the root block
*
* p (the block containing e) must be written before
* anything else.
*/
/* (i) */
memmove(e->score, b->score, VtScoreSize);
vtentrypack(e, p->data, r->offset % r->epb);
/* (ii) */
memmove(ob->data, vtzeroscore, VtScoreSize);
/* (iii) */
vtblockput(rb);
if(ob!=nil && ob!=rb)
vtblockput(ob);
vtblockput(b);
if(DEPTH(e->type) == depth)
return 0;
return -1;
}
static int
shrinksize(VtFile *r, VtEntry *e, uvlong size)
{
int i, depth, type, isdir, ppb;
uvlong ptrsz;
uchar score[VtScoreSize];
VtBlock *b;
b = vtcacheglobal(r->c, e->score, e->type);
if(b == nil)
return -1;
ptrsz = e->dsize;
ppb = e->psize/VtScoreSize;
type = e->type;
depth = DEPTH(type);
for(i=0; i+1<depth; i++)
ptrsz *= ppb;
isdir = r->dir;
while(depth > 0){
if(b->addr == NilBlock){
/* not worth copying the block just so we can zero some of it */
vtblockput(b);
return -1;
}
/*
* invariant: each pointer in the tree rooted at b accounts for ptrsz bytes
*/
/* zero the pointers to unnecessary blocks */
i = (size+ptrsz-1)/ptrsz;
for(; i<ppb; i++)
memmove(b->data+i*VtScoreSize, vtzeroscore, VtScoreSize);
/* recurse (go around again) on the partially necessary block */
i = size/ptrsz;
size = size%ptrsz;
if(size == 0){
vtblockput(b);
return 0;
}
ptrsz /= ppb;
type--;
memmove(score, b->data+i*VtScoreSize, VtScoreSize);
vtblockput(b);
b = vtcacheglobal(r->c, score, type);
if(b == nil)
return -1;
}
if(b->addr == NilBlock){
vtblockput(b);
return -1;
}
/*
* No one ever truncates BtDir blocks.
*/
if(depth==0 && !isdir && e->dsize > size)
memset(b->data+size, 0, e->dsize-size);
vtblockput(b);
return 0;
}
