static int
fileMetaRemove(File *f, char *uid)
{
Block *b;
MetaBlock mb;
MetaEntry me;
int i;
File *up;
up = f->up;
fileWAccess(up, uid);
fileMetaLock(f);
sourceLock(up->msource, OReadWrite);
b = sourceBlock(up->msource, f->boff, OReadWrite);
if(b == nil)
goto Err;
if(!mbUnpack(&mb, b->data, up->msource->dsize))
{
fprint(2, "U\n");
goto Err;
}
if(!mbSearch(&mb, f->dir.elem, &i, &me))
{
fprint(2, "S\n");
goto Err;
}
mbDelete(&mb, i);
mbPack(&mb);
sourceUnlock(up->msource);
blockDirty(b);
blockPut(b);
f->removed = 1;
f->boff = NilBlock;
f->dirty = 0;
fileMetaUnlock(f);
return 1;
Err:
sourceUnlock(up->msource);
blockPut(b);
fileMetaUnlock(f);
return 0;
}
static int
deeFill(DirEntryEnum *dee)
{
int i, n;
Source *meta, *source;
MetaBlock mb;
MetaEntry me;
File *f;
Block *b;
DirEntry *de;
/* clean up first */
for(i=dee->i; i<dee->n; i++)
deCleanup(dee->buf+i);
vtMemFree(dee->buf);
dee->buf = nil;
dee->i = 0;
dee->n = 0;
f = dee->file;
source = f->source;
meta = f->msource;
b = sourceBlock(meta, dee->boff, OReadOnly);
if(b == nil)
goto Err;
if(!mbUnpack(&mb, b->data, meta->dsize))
goto Err;
n = mb.nindex;
dee->buf = vtMemAlloc(n * sizeof(DirEntry));
for(i=0; i<n; i++){
de = dee->buf + i;
meUnpack(&me, &mb, i);
if(!deUnpack(de, &me))
goto Err;
dee->n++;
if(!(de->mode & ModeDir))
if(!dirEntrySize(source, de->entry, de->gen, &de->size))
goto Err;
}
dee->boff++;
blockPut(b);
return 1;
Err:
blockPut(b);
return 0;
}
/*
* the file is locked already
* f->msource is unlocked
*/
static File *
dirLookup(File *f, char *elem)
{
int i;
MetaBlock mb;
MetaEntry me;
Block *b;
Source *meta;
File *ff;
u32int bo, nb;
meta = f->msource;
b = nil;
if(!sourceLock(meta, -1))
return nil;
nb = (sourceGetSize(meta)+meta->dsize-1)/meta->dsize;
for(bo=0; bo<nb; bo++){
b = sourceBlock(meta, bo, OReadOnly);
if(b == nil)
goto Err;
if(!mbUnpack(&mb, b->data, meta->dsize))
goto Err;
if(mbSearch(&mb, elem, &i, &me)){
ff = fileAlloc(f->fs);
if(!deUnpack(&ff->dir, &me)){
fileFree(ff);
goto Err;
}
sourceUnlock(meta);
blockPut(b);
ff->boff = bo;
ff->mode = f->mode;
ff->issnapshot = f->issnapshot;
return ff;
}
blockPut(b);
b = nil;
}
vtSetError(ENoFile);
/* fall through */
Err:
sourceUnlock(meta);
blockPut(b);
return nil;
}
Source *
sourceOpen(Source *r, uint32_t offset, int mode, int issnapshot)
{
uint32_t bn;
Block *b;
assert(sourceIsLocked(r));
if(r->mode == OReadWrite)
assert(r->epoch == r->b->l.epoch);
if(!r->dir) {
vtSetError(ENotDir);
return nil;
}
bn = offset/(r->dsize/VtEntrySize);
b = sourceBlock(r, bn, mode);
if(b == nil)
return nil;
r = sourceAlloc(r->fs, b, r, offset, mode, issnapshot);
blockPut(b);
return r;
}
int
fileWrite(File *f, void *buf, int cnt, vlong offset, char *uid)
{
Source *s;
ulong bn;
int off, dsize, n;
Block *b;
uchar *p;
vlong eof;
if(0)fprint(2, "fileWrite: %s %d, %lld\n", f->dir.elem, cnt, offset);
if(!fileLock(f))
return -1;
s = nil;
if(f->dir.mode & ModeDir){
vtSetError(ENotFile);
goto Err;
}
if(f->source->mode != OReadWrite){
vtSetError(EReadOnly);
goto Err;
}
if(offset < 0){
vtSetError(EBadOffset);
goto Err;
}
fileWAccess(f, uid);
if(!sourceLock(f->source, -1))
goto Err;
s = f->source;
dsize = s->dsize;
eof = sourceGetSize(s);
if(f->dir.mode & ModeAppend)
offset = eof;
bn = offset/dsize;
off = offset%dsize;
p = buf;
while(cnt > 0){
n = cnt;
if(n > dsize-off)
n = dsize-off;
b = sourceBlock(s, bn, n<dsize?OReadWrite:OOverWrite);
if(b == nil){
if(offset > eof)
sourceSetSize(s, offset);
goto Err;
}
memmove(b->data+off, p, n);
off = 0;
cnt -= n;
p += n;
offset += n;
bn++;
blockDirty(b);
blockPut(b);
}
if(offset > eof && !sourceSetSize(s, offset))
goto Err;
sourceUnlock(s);
fileUnlock(f);
return p-(uchar*)buf;
Err:
if(s)
sourceUnlock(s);
fileUnlock(f);
return -1;
}
int
fileRead(File *f, void *buf, int cnt, vlong offset)
{
Source *s;
uvlong size;
u32int bn;
int off, dsize, n, nn;
Block *b;
uchar *p;
if(0)fprint(2, "fileRead: %s %d, %lld\n", f->dir.elem, cnt, offset);
if(!fileRLock(f))
return -1;
if(offset < 0){
vtSetError(EBadOffset);
goto Err1;
}
fileRAccess(f);
if(!sourceLock(f->source, OReadOnly))
goto Err1;
s = f->source;
dsize = s->dsize;
size = sourceGetSize(s);
if(offset >= size)
offset = size;
if(cnt > size-offset)
cnt = size-offset;
bn = offset/dsize;
off = offset%dsize;
p = buf;
while(cnt > 0){
b = sourceBlock(s, bn, OReadOnly);
if(b == nil)
goto Err;
n = cnt;
if(n > dsize-off)
n = dsize-off;
nn = dsize-off;
if(nn > n)
nn = n;
memmove(p, b->data+off, nn);
memset(p+nn, 0, nn-n);
off = 0;
bn++;
cnt -= n;
p += n;
blockPut(b);
}
sourceUnlock(s);
fileRUnlock(f);
return p-(uchar*)buf;
Err:
sourceUnlock(s);
Err1:
fileRUnlock(f);
return -1;
}
/*
* caller must lock f->source and f->msource
* caller must NOT lock the source and msource
* referenced by dir.
*/
static u32int
fileMetaAlloc(File *f, DirEntry *dir, u32int start)
{
u32int nb, bo;
Block *b, *bb;
MetaBlock mb;
int nn;
uchar *p;
int i, n, epb;
MetaEntry me;
Source *s, *ms;
s = f->source;
ms = f->msource;
n = deSize(dir);
nb = (sourceGetSize(ms)+ms->dsize-1)/ms->dsize;
b = nil;
if(start > nb)
start = nb;
for(bo=start; bo<nb; bo++){
b = sourceBlock(ms, bo, OReadWrite);
if(b == nil)
goto Err;
if(!mbUnpack(&mb, b->data, ms->dsize))
goto Err;
nn = (mb.maxsize*FullPercentage/100) - mb.size + mb.free;
if(n <= nn && mb.nindex < mb.maxindex)
break;
blockPut(b);
b = nil;
}
/* add block to meta file */
if(b == nil){
b = sourceBlock(ms, bo, OReadWrite);
if(b == nil)
goto Err;
sourceSetSize(ms, (nb+1)*ms->dsize);
mbInit(&mb, b->data, ms->dsize, ms->dsize/BytesPerEntry);
}
p = mbAlloc(&mb, n);
if(p == nil){
/* mbAlloc might have changed block */
mbPack(&mb);
blockDirty(b);
vtSetError(EBadMeta);
goto Err;
}
mbSearch(&mb, dir->elem, &i, &me);
assert(me.p == nil);
me.p = p;
me.size = n;
dePack(dir, &me);
mbInsert(&mb, i, &me);
mbPack(&mb);
/* meta block depends on super block for qid ... */
bb = cacheLocal(b->c, PartSuper, 0, OReadOnly);
blockDependency(b, bb, -1, nil, nil);
blockPut(bb);
/* ... and one or two dir entries */
epb = s->dsize/VtEntrySize;
bb = sourceBlock(s, dir->entry/epb, OReadOnly);
blockDependency(b, bb, -1, nil, nil);
blockPut(bb);
if(dir->mode & ModeDir){
bb = sourceBlock(s, dir->mentry/epb, OReadOnly);
blockDependency(b, bb, -1, nil, nil);
blockPut(bb);
}
blockDirty(b);
blockPut(b);
return bo;
Err:
blockPut(b);
return NilBlock;
}
File *
fileRoot(Source *r)
{
Block *b;
Source *r0, *r1, *r2;
MetaBlock mb;
MetaEntry me;
File *root, *mr;
Fs *fs;
b = nil;
root = nil;
mr = nil;
r1 = nil;
r2 = nil;
fs = r->fs;
if(!sourceLock(r, -1))
return nil;
r0 = sourceOpen(r, 0, fs->mode, 0);
if(r0 == nil)
goto Err;
r1 = sourceOpen(r, 1, fs->mode, 0);
if(r1 == nil)
goto Err;
r2 = sourceOpen(r, 2, fs->mode, 0);
if(r2 == nil)
goto Err;
mr = fileAlloc(fs);
mr->msource = r2;
r2 = nil;
root = fileAlloc(fs);
root->boff = 0;
root->up = mr;
root->source = r0;
r0->file = root; /* point back to source */
r0 = nil;
root->msource = r1;
r1 = nil;
mr->down = root;
if(!sourceLock(mr->msource, -1))
goto Err;
b = sourceBlock(mr->msource, 0, OReadOnly);
sourceUnlock(mr->msource);
if(b == nil)
goto Err;
if(!mbUnpack(&mb, b->data, mr->msource->dsize))
goto Err;
meUnpack(&me, &mb, 0);
if(!deUnpack(&root->dir, &me))
goto Err;
blockPut(b);
sourceUnlock(r);
fileRAccess(root);
return root;
Err:
blockPut(b);
if(r0)
sourceClose(r0);
if(r1)
sourceClose(r1);
if(r2)
sourceClose(r2);
if(mr)
fileFree(mr);
if(root)
fileFree(root);
sourceUnlock(r);
return nil;
}
/* assumes metaLock is held */
static int
fileMetaFlush2(File *f, char *oelem)
{
File *fp;
Block *b, *bb;
MetaBlock mb;
MetaEntry me, me2;
int i, n;
u32int boff;
if(!f->dirty)
return 0;
if(oelem == nil)
oelem = f->dir.elem;
//print("fileMetaFlush %s->%s\n", oelem, f->dir.elem);
fp = f->up;
if(!sourceLock(fp->msource, -1))
return -1;
/* can happen if source is clri'ed out from under us */
if(f->boff == NilBlock)
goto Err1;
b = sourceBlock(fp->msource, f->boff, OReadWrite);
if(b == nil)
goto Err1;
if(!mbUnpack(&mb, b->data, fp->msource->dsize))
goto Err;
if(!mbSearch(&mb, oelem, &i, &me))
goto Err;
n = deSize(&f->dir);
if(0)fprint(2, "old size %d new size %d\n", me.size, n);
if(mbResize(&mb, &me, n)){
/* fits in the block */
mbDelete(&mb, i);
if(strcmp(f->dir.elem, oelem) != 0)
mbSearch(&mb, f->dir.elem, &i, &me2);
dePack(&f->dir, &me);
mbInsert(&mb, i, &me);
mbPack(&mb);
blockDirty(b);
blockPut(b);
sourceUnlock(fp->msource);
f->dirty = 0;
return 1;
}
/*
* moving entry to another block
* it is feasible for the fs to crash leaving two copies
* of the directory entry. This is just too much work to
* fix. Given that entries are only allocated in a block that
* is less than PercentageFull, most modifications of meta data
* will fit within the block. i.e. this code should almost
* never be executed.
*/
boff = fileMetaAlloc(fp, &f->dir, f->boff+1);
if(boff == NilBlock){
/* mbResize might have modified block */
mbPack(&mb);
blockDirty(b);
goto Err;
}
fprint(2, "fileMetaFlush moving entry from %ud -> %ud\n", f->boff, boff);
f->boff = boff;
/* make sure deletion goes to disk after new entry */
bb = sourceBlock(fp->msource, f->boff, OReadWrite);
mbDelete(&mb, i);
mbPack(&mb);
blockDependency(b, bb, -1, nil, nil);
blockPut(bb);
blockDirty(b);
blockPut(b);
sourceUnlock(fp->msource);
f->dirty = 0;
return 1;
Err:
blockPut(b);
Err1:
sourceUnlock(fp->msource);
return -1;
}
/*
* Walk the source tree making sure that the BtData
* sources containing directory entries are okay.
*/
static void
chkDir(Fsck *chk, char *name, Source *source, Source *meta)
{
int i;
u32int a1, a2, nb, o;
char *s, *nn;
uchar *bm;
Block *b, *bb;
DirEntry de;
Entry e1, e2;
MetaBlock mb;
MetaEntry me;
Source *r, *mr;
if(!chk->useventi && globalToLocal(source->score)==NilBlock &&
globalToLocal(meta->score)==NilBlock)
return;
if(!sourceLock2(source, meta, OReadOnly)){
warn(chk, "could not lock sources for %s: %R", name);
return;
}
if(!sourceGetEntry(source, &e1) || !sourceGetEntry(meta, &e2)){
warn(chk, "could not load entries for %s: %R", name);
return;
}
a1 = globalToLocal(e1.score);
a2 = globalToLocal(e2.score);
if((!chk->useventi && a1==NilBlock && a2==NilBlock)
|| (getBit(chk->smap, a1) && getBit(chk->smap, a2))){
sourceUnlock(source);
sourceUnlock(meta);
return;
}
setBit(chk->smap, a1);
setBit(chk->smap, a2);
bm = vtMemAllocZ(sourceGetDirSize(source)/8 + 1);
nb = (sourceGetSize(meta) + meta->dsize - 1)/meta->dsize;
for(o = 0; o < nb; o++){
b = sourceBlock(meta, o, OReadOnly);
if(b == nil){
error(chk, "could not read block in meta file: %s[%ud]: %R",
name, o);
continue;
}
if(0) fprint(2, "source %V:%d block %d addr %d\n", source->score,
source->offset, o, b->addr);
if(b->addr != NilBlock && getBit(chk->errmap, b->addr))
warn(chk, "previously reported error in block %ux is in %s",
b->addr, name);
if(!mbUnpack(&mb, b->data, meta->dsize)){
error(chk, "could not unpack meta block: %s[%ud]: %R",
name, o);
blockPut(b);
continue;
}
if(!chkMetaBlock(&mb)){
error(chk, "bad meta block: %s[%ud]: %R", name, o);
blockPut(b);
continue;
}
s = nil;
for(i=mb.nindex-1; i>=0; i--){
meUnpack(&me, &mb, i);
if(!deUnpack(&de, &me)){
error(chk,
"could not unpack dir entry: %s[%ud][%d]: %R",
name, o, i);
continue;
}
if(s && strcmp(s, de.elem) <= 0)
error(chk,
"dir entry out of order: %s[%ud][%d] = %s last = %s",
name, o, i, de.elem, s);
vtMemFree(s);
s = vtStrDup(de.elem);
nn = smprint("%s/%s", name, de.elem);
if(nn == nil){
error(chk, "out of memory");
continue;
}
if(chk->printdirs)
if(de.mode&ModeDir)
chk->print("%s/\n", nn);
if(chk->printfiles)
if(!(de.mode&ModeDir))
chk->print("%s\n", nn);
if(!(de.mode & ModeDir)){
r = openSource(chk, source, nn, bm, de.entry,
de.gen, 0, &mb, i, b);
if(r != nil){
if(sourceLock(r, OReadOnly)){
scanSource(chk, nn, r);
sourceUnlock(r);
}
sourceClose(r);
}
deCleanup(&de);
free(nn);
continue;
}
r = openSource(chk, source, nn, bm, de.entry,
de.gen, 1, &mb, i, b);
if(r == nil){
deCleanup(&de);
free(nn);
continue;
}
mr = openSource(chk, source, nn, bm, de.mentry,
de.mgen, 0, &mb, i, b);
if(mr == nil){
sourceClose(r);
deCleanup(&de);
free(nn);
continue;
}
if(!(de.mode&ModeSnapshot) || chk->walksnapshots)
chkDir(chk, nn, r, mr);
sourceClose(mr);
sourceClose(r);
deCleanup(&de);
free(nn);
deCleanup(&de);
}
vtMemFree(s);
blockPut(b);
}
nb = sourceGetDirSize(source);
for(o=0; o<nb; o++){
if(getBit(bm, o))
continue;
r = sourceOpen(source, o, OReadOnly, 0);
if(r == nil)
continue;
warn(chk, "non referenced entry in source %s[%d]", name, o);
if((bb = sourceBlock(source, o/(source->dsize/VtEntrySize),
OReadOnly)) != nil){
if(bb->addr != NilBlock){
setBit(chk->errmap, bb->addr);
chk->clre(chk, bb, o%(source->dsize/VtEntrySize));
chk->nclre++;
}
blockPut(bb);
}
sourceClose(r);
}
sourceUnlock(source);
sourceUnlock(meta);
vtMemFree(bm);
}
/*
* 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 sources (OReadWrite) and sources for the
* snapshot file system (OReadOnly).
*/
static Block*
sourceLoadBlock(Source *r, int mode)
{
uint32_t addr;
Block *b;
switch(r->mode) {
default:
assert(0);
case OReadWrite:
assert(r->mode == OReadWrite);
/*
* This needn't be true -- we might bump the low epoch
* to reclaim some old blocks, but since this score is
* OReadWrite, the blocks must all still be open, so none
* are reclaimed. Thus it's okay that the epoch is so low.
* Proceed.
assert(r->epoch >= r->fs->elo);
*/
if(r->epoch == r->fs->ehi) {
b = cacheGlobal(r->fs->cache, r->score, BtDir, r->tag, OReadWrite);
if(b == nil)
return nil;
assert(r->epoch == b->l.epoch);
return b;
}
assert(r->parent != nil);
if(!sourceLock(r->parent, OReadWrite))
return nil;
b = sourceBlock(r->parent, r->offset/r->epb, OReadWrite);
sourceUnlock(r->parent);
if(b == nil)
return nil;
assert(b->l.epoch == r->fs->ehi);
// fprint(2, "sourceLoadBlock %p %V => %V\n", r, r->score, b->score);
memmove(r->score, b->score, VtScoreSize);
r->scoreEpoch = b->l.epoch;
r->tag = b->l.tag;
r->epoch = r->fs->ehi;
return b;
case OReadOnly:
addr = globalToLocal(r->score);
if(addr == NilBlock)
return cacheGlobal(r->fs->cache, r->score, BtDir, r->tag, mode);
b = cacheLocalData(r->fs->cache, addr, BtDir, r->tag, mode, r->scoreEpoch);
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 OReadWrite case
* above because blocks in the current epoch don't get
* reclaimed. The fact that we're OReadOnly means we're
* a snapshot. (Or else the file system is read-only, but then
* the archiver isn't going around deleting blocks.)
*/
if(strcmp(vtGetError(), ELabelMismatch) == 0) {
if(!sourceLock(r->parent, OReadOnly))
return nil;
b = sourceBlock(r->parent, r->offset/r->epb, OReadOnly);
sourceUnlock(r->parent);
if(b) {
fprint(2, "sourceAlloc: lost %V found %V\n",
r->score, b->score);
memmove(r->score, b->score, VtScoreSize);
r->scoreEpoch = b->l.epoch;
return b;
}
}
return nil;
}
}
Source *
sourceCreate(Source *r, int dsize, int dir, uint32_t offset)
{
int i, epb, psize;
uint32_t bn, size;
Block *b;
Entry e;
Source *rr;
assert(sourceIsLocked(r));
if(!r->dir) {
vtSetError(ENotDir);
return nil;
}
epb = r->dsize/VtEntrySize;
psize = (dsize/VtScoreSize)*VtScoreSize;
size = sourceGetDirSize(r);
if(offset == 0) {
/*
* look at a random block to see if we can find an empty entry
*/
offset = lnrand(size+1);
offset -= offset % epb;
}
/* try the given block and then try the last block */
for(;;) {
bn = offset/epb;
b = sourceBlock(r, bn, OReadWrite);
if(b == nil)
return nil;
for(i=offset%r->epb; i<epb; i++) {
entryUnpack(&e, b->data, i);
if((e.flags&VtEntryActive) == 0 && e.gen != ~0)
goto Found;
}
blockPut(b);
if(offset == size) {
fprint(2, "sourceCreate: cannot happen\n");
vtSetError("sourceCreate: cannot happen");
return nil;
}
offset = size;
}
Found:
/* found an entry - gen already set */
e.psize = psize;
e.dsize = dsize;
assert(psize && dsize);
e.flags = VtEntryActive;
if(dir)
e.flags |= VtEntryDir;
e.depth = 0;
e.size = 0;
memmove(e.score, vtZeroScore, VtScoreSize);
e.tag = 0;
e.snap = 0;
e.archive = 0;
entryPack(&e, b->data, i);
blockDirty(b);
offset = bn*epb + i;
if(offset+1 > size) {
if(!sourceSetDirSize(r, offset+1)) {
blockPut(b);
return nil;
}
}
rr = sourceAlloc(r->fs, b, r, offset, OReadWrite, 0);
blockPut(b);
return rr;
}