ref: a291bbdeddfd41a2f0907ecbd7b819f0eedffdaf
dir: /sys/src/cmd/aux/flashfs/entry.c/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
#include "flashfs.h"
static int nextfnum;
static Intmap* map;
static Dir dirproto;
static char user[] = "flash";
Entry *root;
ulong used;
ulong limit;
ulong maxwrite;
enum
{
debug = 0,
};
static int
fnum(void)
{
return ++nextfnum;
}
static void
maxfnum(int n)
{
if(n > nextfnum)
nextfnum = n;
}
static int
hash(char *s)
{
int c, d, h;
h = 0;
while((c = *s++) != '\0') {
d = c;
c ^= c << 6;
h += (c << 11) ^ (c >> 1);
h ^= (d << 14) + (d << 7) + (d << 4) + d;
}
if(h < 0)
return ~h;
return h;
}
static void
dirinit(Entry *e)
{
Entry **t;
e->size = 0;
t = emalloc9p(HSIZE * sizeof(Entry*));
memset(t, 0, HSIZE * sizeof(Entry*));
e->htab = t;
e->files = nil;
e->readers = nil;
}
static void
fileinit(Entry *e)
{
e->size = 0;
e->gen[0].head = nil;
e->gen[0].tail = nil;
e->gen[1].head = nil;
e->gen[1].tail = nil;
}
static void
elfree(Extent *x)
{
Extent *t;
while(x != nil) {
t = x->next;
used -= x->size;
free(x);
x = t;
}
}
static void
extfree(Entry *e)
{
elfree(e->gen[0].head);
elfree(e->gen[1].head);
}
static void
efree(Entry *e)
{
if(debug)
fprint(2, "free %s\n", e->name);
if(e->mode & DMDIR)
free(e->htab);
else
extfree(e);
free(e->name);
free(e);
}
void
einit(void)
{
Entry *e;
e = emalloc9p(sizeof(Entry));
e->ref = 1;
e->parent = nil;
dirinit(e);
e->name = estrdup9p("");
e->fnum = 0;
e->mode = DMDIR | 0775;
e->mnum = 0;
e->mtime = 0;
root = e;
map = allocmap(nil);
}
static void
dumptree(Entry *e, int n)
{
Entry *l;
if(debug)
fprint(2, "%d %s %d\n", n, e->name, e->ref);
if(e->mode & DMDIR) {
n++;
for(l = e->files; l != nil; l = l->fnext)
dumptree(l, n);
}
}
void
edump(void)
{
if(debug)
dumptree(root, 0);
}
Entry *
elookup(ulong key)
{
if(key == 0)
return root;
maxfnum(key);
return lookupkey(map, key);
}
Extent *
esum(Entry *e, int sect, ulong addr, int *more)
{
Exts *x;
Extent *t, *u;
x = &e->gen[eparity];
t = x->tail;
if(t == nil || t->sect != sect || t->addr != addr)
return nil;
u = t->prev;
if(u != nil) {
u->next = nil;
*more = 1;
}
else {
x->head = nil;
*more = 0;
}
x->tail = u;
x = &e->gen[eparity^1];
u = x->head;
t->next = u;
x->head = t;
if(u == nil)
x->tail = t;
else
u->prev = t;
return t;
}
void
edestroy(Entry *e)
{
e->ref--;
if(e->ref == 0)
efree(e);
}
Entry *
ecreate(Entry *d, char *name, ulong n, ulong mode, ulong mtime, char **err)
{
int h;
Entry *e, *f;
h = hash(name) & HMASK;
for(e = d->htab[h]; e != nil; e = e->hnext) {
if(strcmp(e->name, name) == 0) {
*err = Eexists;
return nil;
}
}
e = emalloc9p(sizeof(Entry));
e->ref = 1;
e->parent = d;
d->ref++;
f = d->htab[h];
e->hnext = f;
e->hprev = nil;
if(f != nil)
f->hprev = e;
d->htab[h] = e;
f = d->files;
e->fnext = f;
e->fprev = nil;
if(f != nil)
f->fprev = e;
d->files = e;
d->ref--;
e->ref++;
e->name = estrdup9p(name);
if(n == 0)
n = fnum();
else
maxfnum(n);
insertkey(map, n, e);
e->fnum = n;
e->mode = mode & d->mode;
e->mnum = 0;
e->mtime = mtime;
if(e->mode & DMDIR)
dirinit(e);
else
fileinit(e);
d->mtime = mtime;
return e;
}
void
etrunc(Entry *e, ulong n, ulong mtime)
{
extfree(e);
deletekey(map, e->fnum);
if(n == 0)
n = fnum();
else
maxfnum(n);
e->fnum = n;
e->mnum = 0;
e->mtime = mtime;
insertkey(map, n, e);
fileinit(e);
e->parent->mtime = mtime;
}
char *
eremove(Entry *e)
{
Dirr *r;
Entry *d, *n, *p;
d = e->parent;
if(d == nil)
return Eperm;
if((e->mode & DMDIR) != 0 && e->files != nil)
return Edirnotempty;
p = e->hprev;
n = e->hnext;
if(n != nil)
n->hprev = p;
if(p != nil)
p->hnext = n;
else
d->htab[hash(e->name) & HMASK] = n;
for(r = d->readers; r != nil; r = r->next) {
if(r->cur == e)
r->cur = e->fnext;
}
p = e->fprev;
n = e->fnext;
if(n != nil)
n->fprev = p;
if(p != nil)
p->fnext = n;
else
d->files = n;
e->parent = nil;
d->ref--;
deletekey(map, e->fnum);
edestroy(e);
return nil;
}
Entry *
ewalk(Entry *d, char *name, char **err)
{
Entry *e;
if((d->mode & DMDIR) == 0) {
*err = Enotdir;
return nil;
}
if(strcmp(name, "..") == 0) {
e = d->parent;
if(e == nil)
return d;
edestroy(d);
e->ref++;
return e;
}
for(e = d->htab[hash(name) & HMASK]; e != nil; e = e->hnext) {
if(strcmp(e->name, name) == 0) {
d->ref--;
e->ref++;
return e;
}
}
*err = Enonexist;
return nil;
}
static void
eread0(Extent *e, Extent *x, uchar *a, ulong n, ulong off)
{
uchar *a0, *a1;
ulong n0, n1, o0, o1, d, z;
for(;;) {
while(e != nil) {
if(off < e->off + e->size && off + n > e->off) {
if(off >= e->off) {
d = off - e->off;
z = e->size - d;
if(n <= z) {
readdata(e->sect, a, n, e->addr + d);
return;
}
readdata(e->sect, a, z, e->addr + d);
a += z;
n -= z;
off += z;
}
else {
a0 = a;
n0 = e->off - off;
o0 = off;
a += n0;
n -= n0;
off += n0;
z = e->size;
if(n <= z) {
readdata(e->sect, a, n, e->addr);
a = a0;
n = n0;
off = o0;
}
else {
readdata(e->sect, a, z, e->addr);
a1 = a + z;
n1 = n - z;
o1 = off + z;
if(n0 < n1) {
eread0(e->next, x, a0, n0, o0);
a = a1;
n = n1;
off = o1;
}
else {
eread0(e->next, x, a1, n1, o1);
a = a0;
n = n0;
off = o0;
}
}
}
}
e = e->next;
}
if(x == nil)
break;
e = x;
x = nil;
}
memset(a, 0, n);
}
ulong
eread(Entry *e, int parity, void *a, ulong n, ulong off)
{
if(n + off >= e->size)
n = e->size - off;
if(n <= 0)
return 0;
eread0(e->gen[parity].head, e->gen[parity^1].head, a, n, off);
return n;
}
void
ewrite(Entry *e, Extent *x, int parity, ulong mtime)
{
ulong z;
Extent *t;
t = e->gen[parity].head;
x->next = t;
x->prev = nil;
e->gen[parity].head = x;
if(t == nil)
e->gen[parity].tail = x;
else
t->prev = x;
if(mtime != 0)
e->mtime = mtime;
used += x->size;
z = x->off + x->size;
if(z > e->size)
e->size = z;
}
ulong
echmod(Entry *e, ulong mode, ulong mnum)
{
if(mnum != 0)
e->mnum = mnum;
else
e->mnum++;
e->mode &= ~0777;
e->mode |= mode;
return e->mnum;
}
Qid
eqid(Entry *e)
{
Qid qid;
if(e->mode & DMDIR)
qid.type = QTDIR;
else
qid.type = 0;
qid.path = e->fnum;
return qid;
}
void
estat(Entry *e, Dir *d, int alloc)
{
d->type = 'z';
d->dev = 0;
if(alloc) {
d->uid = estrdup9p(user);
d->gid = estrdup9p(user);
d->muid = estrdup9p(user);
d->name = estrdup9p(e->name);
}
else {
d->uid = user;
d->gid = user;
d->muid = user;
d->name = e->name;
}
d->mode = e->mode;
d->length = e->size;
d->atime = e->mtime;
d->mtime = e->mtime;
d->qid = eqid(e);
}
Dirr *
ediropen(Entry *e)
{
Dirr *d, *t;
d = emalloc9p(sizeof(Dirr));
d->dir = e;
d->cur = e->files;
t = e->readers;
d->next = t;
d->prev = nil;
if(t != nil)
t->prev = d;
e->readers = d;
e->ref++;
return d;
}
int
edirread(Dirr *r, char *a, long n)
{
Dir d;
Entry *e;
int m, x;
m = 0;
for(e = r->cur; e != nil; e = e->fnext) {
estat(e, &d, 0);
x = convD2M(&d, (uchar *)a, n);
if(x <= BIT16SZ)
break;
a += x;
n -= x;
m += x;
}
r->cur = e;
return m;
}
void
edirclose(Dirr *d)
{
Entry *e;
Dirr *p, *n;
e = d->dir;
p = d->prev;
n = d->next;
if(n != nil)
n->prev = p;
if(p != nil)
p->next = n;
else
e->readers = n;
edestroy(e);
free(d);
}
static Renum R;
static void
xrenum(Extent *x)
{
while(x != nil) {
if(x->sect == R.old)
x->sect = R.new;
x = x->next;
}
}
static void
renum(Entry *e)
{
if(e->mode & DMDIR) {
for(e = e->files; e != nil; e = e->fnext)
renum(e);
}
else {
xrenum(e->gen[0].head);
xrenum(e->gen[1].head);
}
}
void
erenum(Renum *r)
{
R = *r;
renum(root);
}