ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset)
{
//printf("INTERCEPTED pwrite\n");
clock_t start = clock();
ssize_t ret = _pwrite(fd,buf,count,offset);
clock_t end = clock();
double called_time = (double)(start-program_start)/(double)(CLOCKS_PER_SEC);
double exec_time = (double)(end-start)/(double)(CLOCKS_PER_SEC);
fprintf(logFile,"%lf %lf pwrite %d %p %zu %ld = %zu\n",called_time,exec_time,fd,buf,count,offset,ret);
return ret;
}
ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
{
const char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t written = _pwrite(fd, p, count, offset);
if (unlikely(written < 0))
return -1;
if (unlikely(!written)) {
errno = ENOSPC;
return -1;
}
count -= written;
p += written;
total += written;
offset += written;
}
return total;
}
/**
* ntfs_pwrite - positioned write to disk
* @dev: device to write to
* @pos: position in file descriptor to write to
* @count: number of bytes to write
* @b: data buffer to write to disk
*
* This function will write @count bytes from data buffer @b to the device @dev
* at position @pos.
*
* On success, return the number of successfully written bytes. If this number
* is lower than @count this means that the write has been interrupted in
* flight or that an error was encountered during the write so that the write
* is partial. 0 means nothing was written (also return 0 when @count is 0).
*
* On error and nothing has been written, return -1 with errno set
* appropriately to the return code of either seek, write, or set
* to EINVAL in case of invalid arguments.
*/
s64 ntfs_pwrite(struct ntfs_device *dev, const s64 pos, s64 count,
const void *b)
{
s64 written, total;
struct ntfs_device_operations *dops;
s64 (*_pwrite)(struct ntfs_device *, const void *, s64, s64);
ntfs_log_trace("Entering for pos 0x%llx, count 0x%llx.\n", pos, count);
if (!b || count < 0 || pos < 0) {
errno = EINVAL;
return -1;
}
if (!count)
return 0;
if (NDevReadOnly(dev)) {
errno = EROFS;
return -1;
}
dops = dev->d_ops;
_pwrite = dops->pwrite;
if (!_pwrite)
_pwrite = fake_pwrite;
seek:
/*
* Locate to position if pwrite is to be emulated by seek() + write().
*/
if (_pwrite == fake_pwrite &&
dops->seek(dev, pos, SEEK_SET) == (off_t)-1) {
ntfs_log_perror("ntfs_pwrite: seek to 0x%llx returned error",
pos);
return -1;
}
NDevSetDirty(dev);
/* Write the data. */
for (total = 0; count; count -= written, total += written) {
written = _pwrite(dev, (const char*)b + total, count,
pos + total);
/* If everything ok, continue. */
if (written > 0)
continue;
/*
* If nothing written or error return number of bytes written.
*/
if (!written || total)
break;
/*
* If pwrite is not supported by the OS, fall back to emulating
* it by seek() + write() and set the device pwrite() pointer
* to NULL so we automatically use seek() + write() from now
* on.
*/
if (errno == ENOSYS && _pwrite != fake_pwrite) {
_pwrite = fake_pwrite;
dops->pwrite = NULL;
goto seek;
}
/* Nothing written and error, return error status. */
return written;
}
/* Finally, return the number of bytes written. */
return total;
}
