/*
* offset and count are in bytes, but must be multiples of the sector size
* for files opened with O_DIRECT. buf must be aligned to sector size bytes
* then.
*
* This function may be called without alignment if the caller ensures
* that O_DIRECT is not in effect.
*/
static int raw_pwrite_aligned(BlockDriverState *bs, int64_t offset,
const uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
int ret;
ret = fd_open(bs);
if (ret < 0)
return -errno;
ret = pwrite(s->fd, buf, count, offset);
if (ret == count)
return ret;
DEBUG_BLOCK_PRINT("raw_pwrite(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
"] write failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
return (ret < 0) ? -errno : ret;
}
/*
* offset and count are in bytes, but must be multiples of 512 for files
* opened with O_DIRECT. buf must be aligned to 512 bytes then.
*
* This function may be called without alignment if the caller ensures
* that O_DIRECT is not in effect.
*/
static int raw_pread_aligned(BlockDriverState *bs, int64_t offset,
uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
int ret;
ret = fd_open(bs);
if (ret < 0)
return ret;
if (offset >= 0 && lseek(s->fd, offset, SEEK_SET) == (off_t)-1) {
++(s->lseek_err_cnt);
if(s->lseek_err_cnt <= 10) {
DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
"] lseek failed : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, errno, strerror(errno));
}
return -1;
}
s->lseek_err_cnt=0;
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
/* Allow reads beyond the end (needed for pwrite) */
if ((ret == 0) && bs->growable) {
int64_t size = raw_getlength(bs);
if (offset >= size) {
memset(buf, 0, count);
ret = count;
goto label__raw_read__success;
}
}
DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
"] read failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
/* Try harder for CDrom. */
if (bs->type == BDRV_TYPE_CDROM) {
lseek(s->fd, offset, SEEK_SET);
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
lseek(s->fd, offset, SEEK_SET);
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
"] retry read failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
}
label__raw_read__success:
return (ret < 0) ? -errno : ret;
}
