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#include "stdinc.h"
#include "dat.h"
#include "fns.h"
u32int maxblocksize;
int readonly;
Part*
initpart(char *name, int writable)
{
Part *part;
Dir *dir;
int how;
part = MK(Part);
part->name = estrdup(name);
if(!writable && readonly)
how = OREAD;
else
how = ORDWR;
part->fd = open(name, how);
if(part->fd < 0){
if(how == ORDWR)
part->fd = open(name, OREAD);
if(part->fd < 0){
freepart(part);
seterr(EOk, "can't open partition='%s': %r", name);
return nil;
}
fprint(2, "warning: %s opened for reading only\n", name);
}
dir = dirfstat(part->fd);
if(dir == nil){
freepart(part);
seterr(EOk, "can't stat partition='%s': %r", name);
return nil;
}
part->size = dir->length;
part->blocksize = 0;
free(dir);
return part;
}
void
freepart(Part *part)
{
if(part == nil)
return;
close(part->fd);
free(part->name);
free(part);
}
void
partblocksize(Part *part, u32int blocksize)
{
if(part->blocksize)
sysfatal("resetting partition=%s's block size", part->name);
part->blocksize = blocksize;
if(blocksize > maxblocksize)
maxblocksize = blocksize;
}
int
writepart(Part *part, u64int addr, u8int *buf, u32int n)
{
long m, mm, nn;
qlock(&stats.lock);
stats.diskwrites++;
stats.diskbwrites += n;
qunlock(&stats.lock);
if(addr > part->size || addr + n > part->size){
seterr(ECorrupt, "out of bounds write to partition='%s'", part->name);
return -1;
}
print("write %s %lud at %llud\n", part->name, n, addr);
for(nn = 0; nn < n; nn += m){
mm = n - nn;
if(mm > MaxIo)
mm = MaxIo;
m = pwrite(part->fd, &buf[nn], mm, addr + nn);
if(m != mm){
if(m < 0){
seterr(EOk, "can't write partition='%s': %r", part->name);
return -1;
}
logerr(EOk, "truncated write to partition='%s' n=%ld wrote=%ld", part->name, mm, m);
}
}
return 0;
}
int
readpart(Part *part, u64int addr, u8int *buf, u32int n)
{
long m, mm, nn;
int i;
qlock(&stats.lock);
stats.diskreads++;
stats.diskbreads += n;
qunlock(&stats.lock);
if(addr > part->size || addr + n > part->size){
seterr(ECorrupt, "out of bounds read from partition='%s': addr=%lld n=%d size=%lld", part->name, addr, n, part->size);
return -1;
}
print("read %s %lud at %llud\n", part->name, n, addr);
for(nn = 0; nn < n; nn += m){
mm = n - nn;
if(mm > MaxIo)
mm = MaxIo;
m = -1;
for(i=0; i<4; i++) {
m = pread(part->fd, &buf[nn], mm, addr + nn);
if(m == mm)
break;
}
if(m != mm){
if(m < 0){
seterr(EOk, "can't read partition='%s': %r", part->name);
return -1;
}
logerr(EOk, "warning: truncated read from partition='%s' n=%ld read=%ld", part->name, mm, m);
}
}
return 0;
}
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