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#include "all.h"
enum{
MAXWREN = 7,
};
#define WMAGIC "kfs wren device\n"
typedef struct Wren Wren;
struct Wren{
QLock;
Device dev;
uvlong size;
int fd;
};
static Wren *wrens;
static int maxwren;
char *wrenfile;
int nwren;
int badmagic;
static Wren *
wren(Device dev)
{
int i;
for(i = 0; i < maxwren; i++)
if(devcmp(dev, wrens[i].dev) == 0)
return &wrens[i];
panic("can't find wren for %D", dev);
return 0;
}
void
wreninit(Device dev)
{
char buf[MAXBUFSIZE];
Wren *w;
Dir *d;
int fd, i;
if(wrens == 0)
wrens = ialloc(MAXWREN * sizeof *wrens);
w = &wrens[maxwren];
fd = open(wrenfile, ORDWR);
if(fd < 0)
panic("can't open %s", wrenfile);
if((d = dirfstat(fd)) == nil)
panic("can't stat %s\n", wrenfile);
seek(fd, 0, 0);
i = read(fd, buf, sizeof buf);
if(i < sizeof buf)
panic("can't read %s", wrenfile);
badmagic = 0;
RBUFSIZE = 1024;
if(strncmp(buf+256, WMAGIC, strlen(WMAGIC)) == 0){
RBUFSIZE = atol(buf+256+strlen(WMAGIC));
if(RBUFSIZE % 512){
fprint(2, "kfs: bad buffersize(%d): assuming 1k blocks\n", RBUFSIZE);
RBUFSIZE = 1024;
}
}else
badmagic = 1;
w->dev = dev;
w->size = d->length;
free(d);
w->fd = fd;
maxwren++;
}
void
wrenream(Device dev)
{
Wren *w;
char buf[MAXBUFSIZE];
int fd, i;
if(RBUFSIZE % 512)
panic("kfs: bad buffersize(%d): restart a multiple of 512\n", RBUFSIZE);
if(RBUFSIZE > sizeof(buf))
panic("kfs: bad buffersize(%d): must be at most %d\n", RBUFSIZE, sizeof(buf));
print("kfs: reaming the file system using %d byte blocks\n", RBUFSIZE);
w = wren(dev);
fd = w->fd;
memset(buf, 0, sizeof buf);
sprint(buf+256, "%s%d\n", WMAGIC, RBUFSIZE);
qlock(w);
i = seek(fd, 0, 0) < 0 || write(fd, buf, RBUFSIZE) != RBUFSIZE;
qunlock(w);
if(i < 0)
panic("can't ream disk");
}
int
wrentag(char *p, int tag, long qpath)
{
Tag *t;
t = (Tag*)(p+BUFSIZE);
return t->tag != tag || (qpath&~QPDIR) != t->path;
}
int
wrencheck(Device dev)
{
char buf[MAXBUFSIZE];
if(badmagic)
return 1;
if(RBUFSIZE > sizeof(buf))
panic("kfs: bad buffersize(%d): must be at most %d\n", RBUFSIZE, sizeof(buf));
if(wrenread(dev, wrensuper(dev), buf) || wrentag(buf, Tsuper, QPSUPER)
|| wrenread(dev, wrenroot(dev), buf) || wrentag(buf, Tdir, QPROOT))
return 1;
if(((Dentry *)buf)[0].mode & DALLOC)
return 0;
return 1;
}
long
wrensize(Device dev)
{
return wren(dev)->size / RBUFSIZE;
}
long
wrensuper(Device dev)
{
USED(dev);
return 1;
}
long
wrenroot(Device dev)
{
USED(dev);
return 2;
}
int
wrenread(Device dev, long addr, void *b)
{
Wren *w;
int fd, i;
w = wren(dev);
fd = w->fd;
qlock(w);
i = seek(fd, (vlong)addr*RBUFSIZE, 0) == -1 || read(fd, b, RBUFSIZE) != RBUFSIZE;
qunlock(w);
if(i)
print("wrenread failed: %r\n");
return i;
}
int
wrenwrite(Device dev, long addr, void *b)
{
Wren *w;
int fd, i;
w = wren(dev);
fd = w->fd;
qlock(w);
i = seek(fd, (vlong)addr*RBUFSIZE, 0) == -1 || write(fd, b, RBUFSIZE) != RBUFSIZE;
qunlock(w);
if(i)
print("wrenwrite failed: %r\n");
return i;
}
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