ref: 7eafe2899062ca12c157571455aa4076becd995c
dir: /clone.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
enum {
Nfileprocs = 4,
Nblkprocs = 16,
Blksz = 128*1024,
};
typedef struct Waitgroup Waitgroup;
typedef struct File File;
typedef struct Blk Blk;
struct Waitgroup {
Rendez;
QLock;
Ref;
};
struct File {
Dir;
Waitgroup wg;
Channel *errchan;
char *src, *dst;
int sfd, dfd;
};
struct Blk {
File *f;
long sz;
vlong offset;
};
int errors = 0;
int multisrc = 0;
int keepmode = 0;
int keepmtime = 0;
int keepuser = 0;
int keepgroup = 0;
int notemp = 0;
int blksz = Blksz;
int fileprocs = Nfileprocs;
int blkprocs = Nblkprocs;
long salt;
Dir *skipdir;
Channel *filechan; /* chan(File*) */
Channel *blkchan; /* chan(Blk*) */
void
usage(void)
{
fprint(2, "usage: %s [-guxT] [-b blocksize] [-p fileprocs:blockprocs] from ... to\n", argv0);
exits("usage");
}
void
error(char *fmt, ...)
{
va_list arg;
char err[ERRMAX];
errors = 1;
snprint(err, sizeof err, "%s: %s\n", argv0, fmt);
va_start(arg, fmt);
vfprint(2, err, arg);
va_end(arg);
}
void *
emalloc(ulong n)
{
void *p;
p = malloc(n);
if(p == nil)
sysfatal("malloc: %r");
return p;
}
char *
estrdup(char *s)
{
char *p;
p = strdup(s);
if(p == nil)
sysfatal("strdup: %r");
return p;
}
extern int cas(long *p, long ov, long nv);
void
wginit(Waitgroup *wg, long n)
{
memset(wg, 0, sizeof(*wg));
wg->l = &wg->QLock;
if(cas(&wg->ref, 0, n) == 0)
sysfatal("wginit: cas failed");
}
void
wgadd(Waitgroup *wg, long n)
{
long v;
v = wg->ref;
while(cas(&wg->ref, v, v+n) == 0)
v = wg->ref;
}
void
wgdone(Waitgroup *wg)
{
if(decref(wg) == 0){
qlock(wg);
rwakeupall(wg);
qunlock(wg);
}
}
void
wgwait(Waitgroup *wg)
{
qlock(wg);
while(wg->ref != 0)
rsleep(wg);
qunlock(wg);
}
char *
filename(char *s)
{
char *p;
p = strrchr(s, '/');
if(p == nil || p == s)
return s;
if(p[1] == 0){
*p = 0;
return filename(s);
}
return p + 1;
}
int
same(Dir *a, Dir *b)
{
if(a->type == b->type &&
a->dev == b->dev &&
a->qid.path == b->qid.path &&
a->qid.type == b->qid.type &&
a->qid.vers == b->qid.vers)
return 1;
return 0;
}
File *
filenew(char *src, char *dst, Dir *d)
{
File *f;
f = emalloc(sizeof(File));
memmove(f, d, sizeof(Dir));
f->uid = estrdup(d->uid);
f->gid = estrdup(d->gid);
f->src = estrdup(src);
f->dst = estrdup(dst);
f->sfd = -1;
f->dfd = -1;
f->errchan = chancreate(sizeof(ulong), 0);
return f;
}
void
filefree(File *f)
{
if(f->sfd >= 0)
close(f->sfd);
if(f->dfd >= 0)
close(f->dfd);
free(f->uid);
free(f->gid);
free(f->src);
free(f->dst);
chanfree(f->errchan);
free(f);
}
int
cloneattr(int fd, Dir *d)
{
Dir dd;
if(!(keepmode || keepuser || keepgroup || keepmtime))
return 1;
nulldir(&dd);
if(keepmode)
dd.mode = d->mode&DMDIR ? d->mode|0200 : d->mode;
if(keepmtime)
dd.mtime = d->mtime;
if(keepuser)
dd.uid = d->uid;
if(keepgroup)
dd.gid = d->gid;
if(dirfwstat(fd, &dd) < 0){
error("can't wstat: %r");
return -1;
}
return 1;
}
int
mkdir(char *src, char *dst, Dir *sd, Dir **dd)
{
int fd;
Dir d;
if(!(sd->mode & 0400)){
error("can't clone directory: '%s' permission denied", src);
return -1;
}
d = *sd;
d.mode = d.mode | DMDIR | 0200;
fd = create(dst, 0, d.mode);
if(fd < 0){
error("can't create directory: %r");
return -1;
}
if(cloneattr(fd, &d) < 0){
close(fd);
return -1;
}
if(dd){
*dd = dirfstat(fd);
if(*dd == nil){
error("can't stat: %r");
close(fd);
return -1;
}
}
close(fd);
return 1;
}
void
clonedir(char *src, char *dst)
{
int fd;
long n;
char *sn, *dn;
Dir *dirs, *d;
File *f;
dirs = nil;
fd = open(src, OREAD);
if(fd < 0){
error("can't open: %r");
return;
}
n = dirreadall(fd, &dirs);
if(n < 0){
error("can't read directory: %r");
close(fd);
return;
}
close(fd);
for(d = dirs; n; n--, d++){
if(d->mode & DMDIR && same(skipdir, d))
continue;
sn = smprint("%s/%s", src, d->name);
dn = smprint("%s/%s", dst, d->name);
if(d->mode & DMDIR){
if(mkdir(sn, dn, d, nil) < 0)
continue;
clonedir(sn, dn);
}else{
f = filenew(sn, dn, d);
sendp(filechan, f);
}
free(sn);
free(dn);
}
free(dirs);
}
void
clone(char *src, char *dst)
{
char *dn;
Dir *sd, *dd;
File *f;
dn = estrdup(dst);
dd = nil;
sd = dirstat(src);
if(sd == nil){
error("can't stat: %r");
return;
}
if(access(dn, AEXIST) >= 0){
dd = dirstat(dn);
if(dd == nil){
error("can't stat: %r");
goto End;
}
}else if(multisrc){
if(mkdir(src, dn, sd, &dd) < 0)
goto End;
skipdir = dd;
}
/* clone a file */
if(!(sd->mode & DMDIR)){
if(dd && dd->mode & DMDIR)
dn = smprint("%s/%s", dn, filename(src));
f = filenew(src, dn, sd);
sendp(filechan, f);
goto End;
}
/* clone a directory */
if(dd)
dn = smprint("%s/%s", dn, filename(src));
if(skipdir){
if(mkdir(src, dn, sd, nil) < 0)
goto End;
}else{
if(mkdir(src, dn, sd, &skipdir) < 0)
goto End;
}
clonedir(src, dn);
End:
free(dn);
free(sd);
free(dd);
}
vlong
blklist(File *f, Blk **bp)
{
long odd;
vlong i, nblk;
Blk *b, *p;
if(f->length == 0)
return 0;
odd = f->length % blksz;
nblk = f->length / blksz + (odd > 0);
b = p = emalloc(sizeof(Blk) * nblk);
for(i = 0; i < nblk; i++, p++){
p->f = f;
p->sz = blksz;
p->offset = blksz * i;
}
if(odd > 0)
b[nblk-1].sz = odd;
*bp = b;
return nblk;
}
int
clonefile(File *f)
{
int ret;
vlong n;
Blk *blks, *b, *be;
enum {Anext, Aerr, Aend};
Alt alts[] = {
[Anext] {blkchan, &b, CHANSND},
[Aerr] {f->errchan, nil, CHANRCV},
[Aend] {nil, nil, CHANEND},
};
ret = 1;
n = blklist(f, &blks);
if(n == 0)
return 1;
wginit(&f->wg, 0);
for(b = blks, be = b + n; b != be; b++)
switch(alt(alts)){
case Anext:
wgadd(&f->wg, 1);
break;
case Aerr:
ret = -1;
goto End;
}
End:
chanclose(f->errchan);
wgwait(&f->wg);
free(blks);
return ret;
}
long
preadn(int fd, void *buf, long nbytes, vlong offset)
{
long nr, n;
vlong o;
char *p;
nr = 0, n = nbytes, o = offset, p = buf;
while(nr < nbytes){
if((n = pread(fd, p, n, o)) < 0)
return -1;
if(n == 0)
break;
nr += n, o += n, p += n;
}
return nr;
}
void
blkproc(void *)
{
int sfd, dfd;
long n;
char *buf;
File *f;
Blk *b;
threadsetname("blkproc");
buf = emalloc(blksz);
for(;;){
b = recvp(blkchan);
if(b == nil)
break;
f = b->f;
sfd = f->sfd;
dfd = f->dfd;
if((n = preadn(sfd, buf, b->sz, b->offset)) < 0){
error("can't read: %r");
sendul(f->errchan, ~0);
}
if(n > 0 && pwrite(dfd, buf, n, b->offset) != n){
error("can't write: %r");
sendul(f->errchan, ~0);
}
wgdone(&f->wg);
}
}
void
fileproc(void *v)
{
char *dst;
Dir d;
File *f;
Waitgroup *wg;
threadsetname("fileproc");
wg = v;
for(;;){
f = recvp(filechan);
if(f == nil)
break;
dst = nil;
f->sfd = open(f->src, OREAD);
if(f->sfd < 0){
error("can't open: %r");
goto End;
}
if(notemp)
dst = estrdup(f->dst);
else
dst = smprint("%s.clone.%ld", f->dst, salt);
f->dfd = create(dst, OWRITE, f->mode);
if(f->dfd < 0){
error("can't create: %r");
goto End;
}
if(clonefile(f) < 0){
if(remove(dst) < 0)
error("can't remove: %r");
goto End;
}
cloneattr(f->dfd, f);
if(notemp)
goto End;
if(dirstat(f->dst) != nil && remove(f->dst) < 0){
error("can't remove: %r");
goto End;
}
nulldir(&d);
d.name = filename(f->dst);
if(dirfwstat(f->dfd, &d) < 0){
error("dirfwstat: %r");
goto End;
}
End:
filefree(f);
free(dst);
}
wgdone(wg);
}
void
threadmain(int argc, char *argv[])
{
int i;
char *dst, *p;
Waitgroup filewg;
salt = time(0);
ARGBEGIN{
case 'b':
blksz = strtol(EARGF(usage()), nil, 0);
break;
case 'p':
fileprocs = strtol(EARGF(usage()), &p, 0);
*p++ = 0;
blkprocs = strtol(p, nil, 0);
break;
case 'x':
keepmode = keepmtime = 1;
break;
case 'u':
keepuser = 1;
break;
case 'g':
keepgroup = 1;
break;
case 'T':
notemp = 1;
break;
}ARGEND;
if(argc < 2)
usage();
if(argc > 2)
multisrc = 1;
dst = argv[argc - 1];
filechan = chancreate(sizeof(File*), fileprocs);
blkchan = chancreate(sizeof(Blk*), blkprocs);
wginit(&filewg, fileprocs);
for(i = 0; i < fileprocs; i++)
proccreate(fileproc, &filewg, mainstacksize);
for(i = 0; i < blkprocs; i++)
proccreate(blkproc, nil, mainstacksize);
for(i = 0; i < argc -1; i++)
clone(argv[i], dst);
chanclose(filechan);
wgwait(&filewg);
if(errors)
threadexitsall("errors");
threadexitsall(nil);
}