提交 7d780669 编写于 作者: A aliguori

Add specialized block driver scsi generic API (Avi Kivity)

When a scsi device is backed by a scsi generic device instead of an
ordinary host block device, the block API is abused in a couple of annoying
ways:

 - nb_sectors is negative, and specifies a byte count instead of a sector count
 - offset is ignored, since scsi-generic is essentially a packet protocol

This overloading makes hacking the block layer difficult.  Remove it by
introducing a new explicit API for scsi-generic devices.  The new API
is still backed by the old implementation, but at least the users are
insulated.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6822 c046a42c-6fe2-441c-8c8c-71466251a162
上级 943984c7
...@@ -1675,3 +1675,25 @@ int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) ...@@ -1675,3 +1675,25 @@ int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
return drv->bdrv_ioctl(bs, req, buf); return drv->bdrv_ioctl(bs, req, buf);
return -ENOTSUP; return -ENOTSUP;
} }
int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count)
{
return bdrv_pwrite(bs, -1, buf, count);
}
int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count)
{
return bdrv_pread(bs, -1, buf, count);
}
BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_read(bs, 0, buf, -(int64_t)count, cb, opaque);
}
BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_write(bs, 0, buf, -(int64_t)count, cb, opaque);
}
...@@ -101,6 +101,14 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num, ...@@ -101,6 +101,14 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
BlockDriverCompletionFunc *cb, void *opaque); BlockDriverCompletionFunc *cb, void *opaque);
void bdrv_aio_cancel(BlockDriverAIOCB *acb); void bdrv_aio_cancel(BlockDriverAIOCB *acb);
/* sg packet commands */
int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count);
int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count);
BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count,
BlockDriverCompletionFunc *cb, void *opaque);
/* Ensure contents are flushed to disk. */ /* Ensure contents are flushed to disk. */
void bdrv_flush(BlockDriverState *bs); void bdrv_flush(BlockDriverState *bs);
void bdrv_flush_all(void); void bdrv_flush_all(void);
......
...@@ -201,6 +201,7 @@ static int execute_command(BlockDriverState *bdrv, ...@@ -201,6 +201,7 @@ static int execute_command(BlockDriverState *bdrv,
SCSIRequest *r, int direction, SCSIRequest *r, int direction,
BlockDriverCompletionFunc *complete) BlockDriverCompletionFunc *complete)
{ {
int ret;
r->io_header.interface_id = 'S'; r->io_header.interface_id = 'S';
r->io_header.dxfer_direction = direction; r->io_header.dxfer_direction = direction;
...@@ -214,25 +215,27 @@ static int execute_command(BlockDriverState *bdrv, ...@@ -214,25 +215,27 @@ static int execute_command(BlockDriverState *bdrv,
r->io_header.usr_ptr = r; r->io_header.usr_ptr = r;
r->io_header.flags |= SG_FLAG_DIRECT_IO; r->io_header.flags |= SG_FLAG_DIRECT_IO;
if (bdrv_pwrite(bdrv, -1, &r->io_header, sizeof(r->io_header)) == -1) { ret = bdrv_sg_send_command(bdrv, &r->io_header, sizeof(r->io_header));
if (ret < 0) {
BADF("execute_command: write failed ! (%d)\n", errno); BADF("execute_command: write failed ! (%d)\n", errno);
return -1; return -1;
} }
if (complete == NULL) { if (complete == NULL) {
int ret; int ret;
r->aiocb = NULL; r->aiocb = NULL;
while ((ret = bdrv_pread(bdrv, -1, &r->io_header, while ((ret = bdrv_sg_recv_response(bdrv, &r->io_header,
sizeof(r->io_header))) == -1 && sizeof(r->io_header))) < 0 &&
errno == EINTR); ret == -EINTR)
if (ret == -1) { ;
if (ret < 0) {
BADF("execute_command: read failed !\n"); BADF("execute_command: read failed !\n");
return -1; return -1;
} }
return 0; return 0;
} }
r->aiocb = bdrv_aio_read(bdrv, 0, (uint8_t*)&r->io_header, r->aiocb = bdrv_sg_aio_read(bdrv, (uint8_t*)&r->io_header,
-(int64_t)sizeof(r->io_header), complete, r); sizeof(r->io_header), complete, r);
if (r->aiocb == NULL) { if (r->aiocb == NULL) {
BADF("execute_command: read failed !\n"); BADF("execute_command: read failed !\n");
return -1; return -1;
...@@ -634,14 +637,15 @@ static int get_blocksize(BlockDriverState *bdrv) ...@@ -634,14 +637,15 @@ static int get_blocksize(BlockDriverState *bdrv)
io_header.sbp = sensebuf; io_header.sbp = sensebuf;
io_header.timeout = 6000; /* XXX */ io_header.timeout = 6000; /* XXX */
ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header)); ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header));
if (ret == -1) if (ret < 0)
return -1; return -1;
while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 && while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 &&
errno == EINTR); ret == -EINTR)
;
if (ret == -1) if (ret < 0)
return -1; return -1;
return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7]; return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
...@@ -671,14 +675,15 @@ static int get_stream_blocksize(BlockDriverState *bdrv) ...@@ -671,14 +675,15 @@ static int get_stream_blocksize(BlockDriverState *bdrv)
io_header.sbp = sensebuf; io_header.sbp = sensebuf;
io_header.timeout = 6000; /* XXX */ io_header.timeout = 6000; /* XXX */
ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header)); ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header));
if (ret == -1) if (ret < 0)
return -1; return -1;
while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 && while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 &&
errno == EINTR); ret == -EINTR)
;
if (ret == -1) if (ret < 0)
return -1; return -1;
return (buf[9] << 16) | (buf[10] << 8) | buf[11]; return (buf[9] << 16) | (buf[10] << 8) | buf[11];
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册