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|
- #include "stdinc.h"
- #include "dat.h"
- #include "fns.h"
- #include "error.h"
- /*
- * locking order is upwards. A thread can hold the lock for a File
- * and then acquire the lock of its parent
- */
- struct File {
- Fs *fs; /* immutable */
- /* meta data for file: protected by the lk in the parent */
- int ref; /* holds this data structure up */
- int partial; /* file was never really open */
- int removed; /* file has been removed */
- int dirty; /* dir is dirty with respect to meta data in block */
- u32int boff; /* block offset within msource for this file's meta data */
- DirEntry dir; /* meta data for this file */
- File *up; /* parent file */
- File *next; /* sibling */
- /* data for file */
- VtLock *lk; /* lock for the following */
- Source *source;
- Source *msource; /* for directories: meta data for children */
- File *down; /* children */
- int mode;
- int issnapshot;
- };
- static int fileMetaFlush2(File*, char*);
- static u32int fileMetaAlloc(File*, DirEntry*, u32int);
- static int fileRLock(File*);
- static void fileRUnlock(File*);
- static int fileLock(File*);
- static void fileUnlock(File*);
- static void fileMetaLock(File*);
- static void fileMetaUnlock(File*);
- static void fileRAccess(File*);
- static void fileWAccess(File*, char*);
- static File *
- fileAlloc(Fs *fs)
- {
- File *f;
- f = vtMemAllocZ(sizeof(File));
- f->lk = vtLockAlloc();
- f->ref = 1;
- f->fs = fs;
- f->boff = NilBlock;
- f->mode = fs->mode;
- return f;
- }
- static void
- fileFree(File *f)
- {
- sourceClose(f->source);
- vtLockFree(f->lk);
- sourceClose(f->msource);
- deCleanup(&f->dir);
- memset(f, ~0, sizeof(File));
- vtMemFree(f);
- }
- /*
- * 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;
- }
- 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 = 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;
- }
- static Source *
- fileOpenSource(File *f, u32int offset, u32int gen, int dir, uint mode, int issnapshot)
- {
- Source *r;
- if(!sourceLock(f->source, mode))
- return nil;
- r = sourceOpen(f->source, offset, mode, issnapshot);
- sourceUnlock(f->source);
- if(r == nil)
- return nil;
- if(r->gen != gen){
- vtSetError(ERemoved);
- goto Err;
- }
- if(r->dir != dir && r->mode != -1){
- fprint(2, "fileOpenSource: dir mismatch %d %d\n", r->dir, dir);
- vtSetError(EBadMeta);
- goto Err;
- }
- return r;
- Err:
- sourceClose(r);
- return nil;
- }
- File *
- _fileWalk(File *f, char *elem, int partial)
- {
- File *ff;
- fileRAccess(f);
- if(elem[0] == 0){
- vtSetError(EBadPath);
- return nil;
- }
- if(!fileIsDir(f)){
- vtSetError(ENotDir);
- return nil;
- }
- if(strcmp(elem, ".") == 0){
- return fileIncRef(f);
- }
- if(strcmp(elem, "..") == 0){
- if(fileIsRoot(f))
- return fileIncRef(f);
- return fileIncRef(f->up);
- }
- if(!fileLock(f))
- return nil;
- for(ff = f->down; ff; ff=ff->next){
- if(strcmp(elem, ff->dir.elem) == 0 && !ff->removed){
- ff->ref++;
- goto Exit;
- }
- }
- ff = dirLookup(f, elem);
- if(ff == nil)
- goto Err;
- if(ff->dir.mode & ModeSnapshot){
- ff->mode = OReadOnly;
- ff->issnapshot = 1;
- }
- if(partial){
- /*
- * Do nothing. We're opening this file only so we can clri it.
- * Usually the sources can't be opened, hence we won't even bother.
- * Be VERY careful with the returned file. If you hand it to a routine
- * expecting ff->source and/or ff->msource to be non-nil, we're
- * likely to dereference nil. FileClri should be the only routine
- * setting partial.
- */
- ff->partial = 1;
- }else if(ff->dir.mode & ModeDir){
- ff->source = fileOpenSource(f, ff->dir.entry, ff->dir.gen, 1, ff->mode, ff->issnapshot);
- ff->msource = fileOpenSource(f, ff->dir.mentry, ff->dir.mgen, 0, ff->mode, ff->issnapshot);
- if(ff->source == nil || ff->msource == nil)
- goto Err;
- }else{
- ff->source = fileOpenSource(f, ff->dir.entry, ff->dir.gen, 0, ff->mode, ff->issnapshot);
- if(ff->source == nil)
- goto Err;
- }
- /* link in and up parent ref count */
- ff->next = f->down;
- f->down = ff;
- ff->up = f;
- fileIncRef(f);
- Exit:
- fileUnlock(f);
- return ff;
- Err:
- fileUnlock(f);
- if(ff != nil)
- fileDecRef(ff);
- return nil;
- }
- File *
- fileWalk(File *f, char *elem)
- {
- return _fileWalk(f, elem, 0);
- }
- File *
- _fileOpen(Fs *fs, char *path, int partial)
- {
- File *f, *ff;
- char *p, elem[VtMaxStringSize], *opath;
- int n;
- f = fs->file;
- fileIncRef(f);
- opath = path;
- while(*path != 0){
- for(p = path; *p && *p != '/'; p++)
- ;
- n = p - path;
- if(n > 0){
- if(n > VtMaxStringSize){
- vtSetError("%s: element too long", EBadPath);
- goto Err;
- }
- memmove(elem, path, n);
- elem[n] = 0;
- ff = _fileWalk(f, elem, partial && *p=='\0');
- if(ff == nil){
- vtSetError("%.*s: %R", utfnlen(opath, p-opath), opath);
- goto Err;
- }
- fileDecRef(f);
- f = ff;
- }
- if(*p == '/')
- p++;
- path = p;
- }
- return f;
- Err:
- fileDecRef(f);
- return nil;
- }
- File*
- fileOpen(Fs *fs, char *path)
- {
- return _fileOpen(fs, path, 0);
- }
- static void
- fileSetTmp(File *f, int istmp)
- {
- int i;
- Entry e;
- Source *r;
- for(i=0; i<2; i++){
- if(i==0)
- r = f->source;
- else
- r = f->msource;
- if(r == nil)
- continue;
- if(!sourceGetEntry(r, &e)){
- fprint(2, "sourceGetEntry failed (cannot happen): %r\n");
- continue;
- }
- if(istmp)
- e.flags |= VtEntryNoArchive;
- else
- e.flags &= ~VtEntryNoArchive;
- if(!sourceSetEntry(r, &e)){
- fprint(2, "sourceSetEntry failed (cannot happen): %r\n");
- continue;
- }
- }
- }
- File *
- fileCreate(File *f, char *elem, ulong mode, char *uid)
- {
- File *ff;
- DirEntry *dir;
- Source *pr, *r, *mr;
- int isdir;
- if(!fileLock(f))
- return nil;
- r = nil;
- mr = nil;
- for(ff = f->down; ff; ff=ff->next){
- if(strcmp(elem, ff->dir.elem) == 0 && !ff->removed){
- ff = nil;
- vtSetError(EExists);
- goto Err1;
- }
- }
- ff = dirLookup(f, elem);
- if(ff != nil){
- vtSetError(EExists);
- goto Err1;
- }
- pr = f->source;
- if(pr->mode != OReadWrite){
- vtSetError(EReadOnly);
- goto Err1;
- }
- if(!sourceLock2(f->source, f->msource, -1))
- goto Err1;
- ff = fileAlloc(f->fs);
- isdir = mode & ModeDir;
- r = sourceCreate(pr, pr->dsize, isdir, 0);
- if(r == nil)
- goto Err;
- if(isdir){
- mr = sourceCreate(pr, pr->dsize, 0, r->offset);
- if(mr == nil)
- goto Err;
- }
- dir = &ff->dir;
- dir->elem = vtStrDup(elem);
- dir->entry = r->offset;
- dir->gen = r->gen;
- if(isdir){
- dir->mentry = mr->offset;
- dir->mgen = mr->gen;
- }
- dir->size = 0;
- if(!fsNextQid(f->fs, &dir->qid))
- goto Err;
- dir->uid = vtStrDup(uid);
- dir->gid = vtStrDup(f->dir.gid);
- dir->mid = vtStrDup(uid);
- dir->mtime = time(0L);
- dir->mcount = 0;
- dir->ctime = dir->mtime;
- dir->atime = dir->mtime;
- dir->mode = mode;
- ff->boff = fileMetaAlloc(f, dir, 0);
- if(ff->boff == NilBlock)
- goto Err;
- sourceUnlock(f->source);
- sourceUnlock(f->msource);
- ff->source = r;
- ff->msource = mr;
- if(mode&ModeTemporary){
- if(!sourceLock2(r, mr, -1))
- goto Err1;
- fileSetTmp(ff, 1);
- sourceUnlock(r);
- if(mr)
- sourceUnlock(mr);
- }
- /* committed */
- /* link in and up parent ref count */
- ff->next = f->down;
- f->down = ff;
- ff->up = f;
- fileIncRef(f);
- fileWAccess(f, uid);
- fileUnlock(f);
- return ff;
- Err:
- sourceUnlock(f->source);
- sourceUnlock(f->msource);
- Err1:
- if(r){
- sourceLock(r, -1);
- sourceRemove(r);
- }
- if(mr){
- sourceLock(mr, -1);
- sourceRemove(mr);
- }
- if(ff)
- fileDecRef(ff);
- fileUnlock(f);
- return 0;
- }
- 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;
- }
- /*
- * Changes the file block bn to be the given block score.
- * Very sneaky. Only used by flfmt.
- */
- int
- fileMapBlock(File *f, ulong bn, uchar score[VtScoreSize], ulong tag)
- {
- Block *b;
- Entry e;
- Source *s;
- if(!fileLock(f))
- return 0;
- s = nil;
- if(f->dir.mode & ModeDir){
- vtSetError(ENotFile);
- goto Err;
- }
- if(f->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- goto Err;
- }
- if(!sourceLock(f->source, -1))
- goto Err;
- s = f->source;
- b = _sourceBlock(s, bn, OReadWrite, 1, tag);
- if(b == nil)
- goto Err;
- if(!sourceGetEntry(s, &e))
- goto Err;
- if(b->l.type == BtDir){
- memmove(e.score, score, VtScoreSize);
- assert(e.tag == tag || e.tag == 0);
- e.tag = tag;
- e.flags |= VtEntryLocal;
- entryPack(&e, b->data, f->source->offset % f->source->epb);
- }else
- memmove(b->data + (bn%(e.psize/VtScoreSize))*VtScoreSize, score, VtScoreSize);
- blockDirty(b);
- blockPut(b);
- sourceUnlock(s);
- fileUnlock(f);
- return 1;
- Err:
- if(s)
- sourceUnlock(s);
- fileUnlock(f);
- return 0;
- }
- int
- fileSetSize(File *f, uvlong size)
- {
- int r;
- if(!fileLock(f))
- return 0;
- r = 0;
- if(f->dir.mode & ModeDir){
- vtSetError(ENotFile);
- goto Err;
- }
- if(f->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- goto Err;
- }
- if(!sourceLock(f->source, -1))
- goto Err;
- r = sourceSetSize(f->source, size);
- sourceUnlock(f->source);
- Err:
- fileUnlock(f);
- 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
- fileGetDir(File *f, DirEntry *dir)
- {
- if(!fileRLock(f))
- return 0;
- fileMetaLock(f);
- deCopy(dir, &f->dir);
- fileMetaUnlock(f);
- if(!fileIsDir(f)){
- if(!sourceLock(f->source, OReadOnly)){
- fileRUnlock(f);
- return 0;
- }
- dir->size = sourceGetSize(f->source);
- sourceUnlock(f->source);
- }
- fileRUnlock(f);
- return 1;
- }
- int
- fileTruncate(File *f, char *uid)
- {
- if(fileIsDir(f)){
- vtSetError(ENotFile);
- return 0;
- }
- if(!fileLock(f))
- return 0;
- if(f->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- fileUnlock(f);
- return 0;
- }
- if(!sourceLock(f->source, -1)){
- fileUnlock(f);
- return 0;
- }
- if(!sourceTruncate(f->source)){
- sourceUnlock(f->source);
- fileUnlock(f);
- return 0;
- }
- sourceUnlock(f->source);
- fileUnlock(f);
- fileWAccess(f, uid);
- return 1;
- }
- int
- fileSetDir(File *f, DirEntry *dir, char *uid)
- {
- File *ff;
- char *oelem;
- u32int mask;
- u64int size;
- /* can not set permissions for the root */
- if(fileIsRoot(f)){
- vtSetError(ERoot);
- return 0;
- }
- if(!fileLock(f))
- return 0;
- if(f->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- fileUnlock(f);
- return 0;
- }
- fileMetaLock(f);
- /* check new name does not already exist */
- if(strcmp(f->dir.elem, dir->elem) != 0){
- for(ff = f->up->down; ff; ff=ff->next){
- if(strcmp(dir->elem, ff->dir.elem) == 0 && !ff->removed){
- vtSetError(EExists);
- goto Err;
- }
- }
- ff = dirLookup(f->up, dir->elem);
- if(ff != nil){
- fileDecRef(ff);
- vtSetError(EExists);
- goto Err;
- }
- }
- if(!sourceLock2(f->source, f->msource, -1))
- goto Err;
- if(!fileIsDir(f)){
- size = sourceGetSize(f->source);
- if(size != dir->size){
- if(!sourceSetSize(f->source, dir->size)){
- sourceUnlock(f->source);
- if(f->msource)
- sourceUnlock(f->msource);
- goto Err;
- }
- /* commited to changing it now */
- }
- }
- /* commited to changing it now */
- if((f->dir.mode&ModeTemporary) != (dir->mode&ModeTemporary))
- fileSetTmp(f, dir->mode&ModeTemporary);
- sourceUnlock(f->source);
- if(f->msource)
- sourceUnlock(f->msource);
- oelem = nil;
- if(strcmp(f->dir.elem, dir->elem) != 0){
- oelem = f->dir.elem;
- f->dir.elem = vtStrDup(dir->elem);
- }
- if(strcmp(f->dir.uid, dir->uid) != 0){
- vtMemFree(f->dir.uid);
- f->dir.uid = vtStrDup(dir->uid);
- }
- if(strcmp(f->dir.gid, dir->gid) != 0){
- vtMemFree(f->dir.gid);
- f->dir.gid = vtStrDup(dir->gid);
- }
- f->dir.mtime = dir->mtime;
- f->dir.atime = dir->atime;
- //fprint(2, "mode %x %x ", f->dir.mode, dir->mode);
- mask = ~(ModeDir|ModeSnapshot);
- f->dir.mode &= ~mask;
- f->dir.mode |= mask & dir->mode;
- f->dirty = 1;
- //fprint(2, "->%x\n", f->dir.mode);
- fileMetaFlush2(f, oelem);
- vtMemFree(oelem);
- fileMetaUnlock(f);
- fileUnlock(f);
- fileWAccess(f->up, uid);
- return 1;
- Err:
- fileMetaUnlock(f);
- fileUnlock(f);
- return 0;
- }
- int
- fileSetQidSpace(File *f, u64int offset, u64int max)
- {
- int ret;
- if(!fileLock(f))
- return 0;
- fileMetaLock(f);
- f->dir.qidSpace = 1;
- f->dir.qidOffset = offset;
- f->dir.qidMax = max;
- ret = fileMetaFlush2(f, nil)>=0;
- fileMetaUnlock(f);
- fileUnlock(f);
- return ret;
- }
- uvlong
- fileGetId(File *f)
- {
- /* immutable */
- return f->dir.qid;
- }
- ulong
- fileGetMcount(File *f)
- {
- ulong mcount;
- fileMetaLock(f);
- mcount = f->dir.mcount;
- fileMetaUnlock(f);
- return mcount;
- }
- ulong
- fileGetMode(File *f)
- {
- ulong mode;
- fileMetaLock(f);
- mode = f->dir.mode;
- fileMetaUnlock(f);
- return mode;
- }
- int
- fileIsDir(File *f)
- {
- /* immutable */
- return (f->dir.mode & ModeDir) != 0;
- }
- int
- fileIsRoot(File *f)
- {
- return f == f->fs->file;
- }
- int
- fileIsRoFs(File *f)
- {
- return f->fs->mode == OReadOnly;
- }
- int
- fileGetSize(File *f, uvlong *size)
- {
- if(!fileRLock(f))
- return 0;
- if(!sourceLock(f->source, OReadOnly)){
- fileRUnlock(f);
- return 0;
- }
- *size = sourceGetSize(f->source);
- sourceUnlock(f->source);
- fileRUnlock(f);
- return 1;
- }
- int
- fileMetaFlush(File *f, int rec)
- {
- File **kids, *p;
- int nkids;
- int i, rv;
- fileMetaLock(f);
- rv = fileMetaFlush2(f, nil);
- fileMetaUnlock(f);
- if(!rec || !fileIsDir(f))
- return rv;
- if(!fileLock(f))
- return rv;
- nkids = 0;
- for(p=f->down; p; p=p->next)
- nkids++;
- kids = vtMemAlloc(nkids*sizeof(File*));
- i = 0;
- for(p=f->down; p; p=p->next){
- kids[i++] = p;
- p->ref++;
- }
- fileUnlock(f);
- for(i=0; i<nkids; i++){
- rv |= fileMetaFlush(kids[i], 1);
- fileDecRef(kids[i]);
- }
- vtMemFree(kids);
- return rv;
- }
- /* 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;
- }
- 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;
- }
- /* assume file is locked, assume f->msource is locked */
- static int
- fileCheckEmpty(File *f)
- {
- u32int i, n;
- Block *b;
- MetaBlock mb;
- Source *r;
- r = f->msource;
- n = (sourceGetSize(r)+r->dsize-1)/r->dsize;
- for(i=0; i<n; i++){
- b = sourceBlock(r, i, OReadOnly);
- if(b == nil)
- goto Err;
- if(!mbUnpack(&mb, b->data, r->dsize))
- goto Err;
- if(mb.nindex > 0){
- vtSetError(ENotEmpty);
- goto Err;
- }
- blockPut(b);
- }
- return 1;
- Err:
- blockPut(b);
- return 0;
- }
- int
- fileRemove(File *f, char *uid)
- {
- File *ff;
- /* can not remove the root */
- if(fileIsRoot(f)){
- vtSetError(ERoot);
- return 0;
- }
- if(!fileLock(f))
- return 0;
- if(f->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- goto Err1;
- }
- if(!sourceLock2(f->source, f->msource, -1))
- goto Err1;
- if(fileIsDir(f) && !fileCheckEmpty(f))
- goto Err;
- for(ff=f->down; ff; ff=ff->next)
- assert(ff->removed);
- sourceRemove(f->source);
- f->source = nil;
- if(f->msource){
- sourceRemove(f->msource);
- f->msource = nil;
- }
- fileUnlock(f);
- if(!fileMetaRemove(f, uid))
- return 0;
- return 1;
- Err:
- sourceUnlock(f->source);
- if(f->msource)
- sourceUnlock(f->msource);
- Err1:
- fileUnlock(f);
- return 0;
- }
- static int
- clri(File *f, char *uid)
- {
- int r;
- if(f == nil)
- return 0;
- if(f->up->source->mode != OReadWrite){
- vtSetError(EReadOnly);
- fileDecRef(f);
- return 0;
- }
- r = fileMetaRemove(f, uid);
- fileDecRef(f);
- return r;
- }
- int
- fileClriPath(Fs *fs, char *path, char *uid)
- {
- return clri(_fileOpen(fs, path, 1), uid);
- }
- int
- fileClri(File *dir, char *elem, char *uid)
- {
- return clri(_fileWalk(dir, elem, 1), uid);
- }
- File *
- fileIncRef(File *vf)
- {
- fileMetaLock(vf);
- assert(vf->ref > 0);
- vf->ref++;
- fileMetaUnlock(vf);
- return vf;
- }
- int
- fileDecRef(File *f)
- {
- File *p, *q, **qq;
- if(f->up == nil){
- /* never linked in */
- assert(f->ref == 1);
- fileFree(f);
- return 1;
- }
- fileMetaLock(f);
- f->ref--;
- if(f->ref > 0){
- fileMetaUnlock(f);
- return 0;
- }
- assert(f->ref == 0);
- assert(f->down == nil);
- fileMetaFlush2(f, nil);
- p = f->up;
- qq = &p->down;
- for(q = *qq; q; q = *qq){
- if(q == f)
- break;
- qq = &q->next;
- }
- assert(q != nil);
- *qq = f->next;
- fileMetaUnlock(f);
- fileFree(f);
- fileDecRef(p);
- return 1;
- }
- File *
- fileGetParent(File *f)
- {
- if(fileIsRoot(f))
- return fileIncRef(f);
- return fileIncRef(f->up);
- }
- DirEntryEnum *
- deeOpen(File *f)
- {
- DirEntryEnum *dee;
- File *p;
- if(!fileIsDir(f)){
- vtSetError(ENotDir);
- fileDecRef(f);
- return nil;
- }
- /* flush out meta data */
- if(!fileLock(f))
- return nil;
- for(p=f->down; p; p=p->next)
- fileMetaFlush2(p, nil);
- fileUnlock(f);
- dee = vtMemAllocZ(sizeof(DirEntryEnum));
- dee->file = fileIncRef(f);
- return dee;
- }
- static int
- dirEntrySize(Source *s, ulong elem, ulong gen, uvlong *size)
- {
- Block *b;
- ulong bn;
- Entry e;
- int epb;
- epb = s->dsize/VtEntrySize;
- bn = elem/epb;
- elem -= bn*epb;
- b = sourceBlock(s, bn, OReadOnly);
- if(b == nil)
- goto Err;
- if(!entryUnpack(&e, b->data, elem))
- goto Err;
- /* hanging entries are returned as zero size */
- if(!(e.flags & VtEntryActive) || e.gen != gen)
- *size = 0;
- else
- *size = e.size;
- blockPut(b);
- return 1;
- Err:
- blockPut(b);
- 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;
- }
- int
- deeRead(DirEntryEnum *dee, DirEntry *de)
- {
- int ret, didread;
- File *f;
- u32int nb;
- if(dee == nil){
- vtSetError("cannot happen in deeRead");
- return -1;
- }
- f = dee->file;
- if(!fileRLock(f))
- return -1;
- if(!sourceLock2(f->source, f->msource, OReadOnly)){
- fileRUnlock(f);
- return -1;
- }
- nb = (sourceGetSize(f->msource)+f->msource->dsize-1)/f->msource->dsize;
- didread = 0;
- while(dee->i >= dee->n){
- if(dee->boff >= nb){
- ret = 0;
- goto Return;
- }
- didread = 1;
- if(!deeFill(dee)){
- ret = -1;
- goto Return;
- }
- }
- memmove(de, dee->buf + dee->i, sizeof(DirEntry));
- dee->i++;
- ret = 1;
- Return:
- sourceUnlock(f->source);
- sourceUnlock(f->msource);
- fileRUnlock(f);
- if(didread)
- fileRAccess(f);
- return ret;
- }
- void
- deeClose(DirEntryEnum *dee)
- {
- int i;
- if(dee == nil)
- return;
- for(i=dee->i; i<dee->n; i++)
- deCleanup(dee->buf+i);
- vtMemFree(dee->buf);
- fileDecRef(dee->file);
- vtMemFree(dee);
- }
- /*
- * 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;
- }
- static int
- chkSource(File *f)
- {
- if(f->partial)
- return 1;
- if(f->source == nil || (f->dir.mode & ModeDir) && f->msource == nil){
- vtSetError(ERemoved);
- return 0;
- }
- return 1;
- }
- static int
- fileRLock(File *f)
- {
- assert(!vtCanLock(f->fs->elk));
- vtRLock(f->lk);
- if(!chkSource(f)){
- fileRUnlock(f);
- return 0;
- }
- return 1;
- }
- static void
- fileRUnlock(File *f)
- {
- vtRUnlock(f->lk);
- }
- static int
- fileLock(File *f)
- {
- assert(!vtCanLock(f->fs->elk));
- vtLock(f->lk);
- if(!chkSource(f)){
- fileUnlock(f);
- return 0;
- }
- return 1;
- }
- static void
- fileUnlock(File *f)
- {
- vtUnlock(f->lk);
- }
- /*
- * f->source and f->msource must NOT be locked.
- * fileMetaFlush locks the fileMeta and then the source (in fileMetaFlush2).
- * We have to respect that ordering.
- */
- static void
- fileMetaLock(File *f)
- {
- if(f->up == nil)
- fprint(2, "f->elem = %s\n", f->dir.elem);
- assert(f->up != nil);
- assert(!vtCanLock(f->fs->elk));
- vtLock(f->up->lk);
- }
- static void
- fileMetaUnlock(File *f)
- {
- vtUnlock(f->up->lk);
- }
- /*
- * f->source and f->msource must NOT be locked.
- * see fileMetaLock.
- */
- static void
- fileRAccess(File* f)
- {
- if(f->mode == OReadOnly)
- return;
- fileMetaLock(f);
- f->dir.atime = time(0L);
- f->dirty = 1;
- fileMetaUnlock(f);
- }
- /*
- * f->source and f->msource must NOT be locked.
- * see fileMetaLock.
- */
- static void
- fileWAccess(File* f, char *mid)
- {
- if(f->mode == OReadOnly)
- return;
- fileMetaLock(f);
- f->dir.atime = f->dir.mtime = time(0L);
- if(strcmp(f->dir.mid, mid) != 0){
- vtMemFree(f->dir.mid);
- f->dir.mid = vtStrDup(mid);
- }
- f->dir.mcount++;
- f->dirty = 1;
- fileMetaUnlock(f);
- /*RSC: let's try this */
- /*presotto - lets not
- if(f->up)
- fileWAccess(f->up, mid);
- */
- }
- static int
- getEntry(Source *r, Entry *e, int checkepoch)
- {
- u32int epoch;
- Block *b;
- if(r == nil){
- memset(&e, 0, sizeof e);
- return 1;
- }
- b = cacheGlobal(r->fs->cache, r->score, BtDir, r->tag, OReadOnly);
- if(b == nil)
- return 0;
- if(!entryUnpack(e, b->data, r->offset % r->epb)){
- blockPut(b);
- return 0;
- }
- epoch = b->l.epoch;
- blockPut(b);
- if(checkepoch){
- b = cacheGlobal(r->fs->cache, e->score, entryType(e), e->tag, OReadOnly);
- if(b){
- if(b->l.epoch >= epoch)
- fprint(2, "warning: entry %p epoch not older %#.8ux/%d %V/%d in getEntry\n",
- r, b->addr, b->l.epoch, r->score, epoch);
- blockPut(b);
- }
- }
- return 1;
- }
- static int
- setEntry(Source *r, Entry *e)
- {
- Block *b;
- Entry oe;
- b = cacheGlobal(r->fs->cache, r->score, BtDir, r->tag, OReadWrite);
- if(0) fprint(2, "setEntry: b %#ux %d score=%V\n", b->addr, r->offset % r->epb, e->score);
- if(b == nil)
- return 0;
- if(!entryUnpack(&oe, b->data, r->offset % r->epb)){
- blockPut(b);
- return 0;
- }
- e->gen = oe.gen;
- entryPack(e, b->data, r->offset % r->epb);
- /* BUG b should depend on the entry pointer */
- blockDirty(b);
- blockPut(b);
- return 1;
- }
- /* assumes hold elk */
- int
- fileSnapshot(File *dst, File *src, u32int epoch, int doarchive)
- {
- Entry e, ee;
- /* add link to snapshot */
- if(!getEntry(src->source, &e, 1) || !getEntry(src->msource, &ee, 1))
- return 0;
- e.snap = epoch;
- e.archive = doarchive;
- ee.snap = epoch;
- ee.archive = doarchive;
- if(!setEntry(dst->source, &e) || !setEntry(dst->msource, &ee))
- return 0;
- return 1;
- }
- int
- fileGetSources(File *f, Entry *e, Entry *ee)
- {
- if(!getEntry(f->source, e, 0)
- || !getEntry(f->msource, ee, 0))
- return 0;
- return 1;
- }
- /*
- * Walk down to the block(s) containing the Entries
- * for f->source and f->msource, copying as we go.
- */
- int
- fileWalkSources(File *f)
- {
- if(f->mode == OReadOnly){
- fprint(2, "readonly in fileWalkSources\n");
- return 1;
- }
- if(!sourceLock2(f->source, f->msource, OReadWrite)){
- fprint(2, "sourceLock2 failed in fileWalkSources\n");
- return 0;
- }
- sourceUnlock(f->source);
- sourceUnlock(f->msource);
- return 1;
- }
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