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[Qemu-devel] [6822] Add specialized block driver scsi generic API (Avi K
From: |
Anthony Liguori |
Subject: |
[Qemu-devel] [6822] Add specialized block driver scsi generic API (Avi Kivity) |
Date: |
Thu, 12 Mar 2009 19:57:09 +0000 |
Revision: 6822
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6822
Author: aliguori
Date: 2009-03-12 19:57:08 +0000 (Thu, 12 Mar 2009)
Log Message:
-----------
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: Avi Kivity <address@hidden>
Signed-off-by: Anthony Liguori <address@hidden>
Modified Paths:
--------------
trunk/block.c
trunk/block.h
trunk/hw/scsi-generic.c
Modified: trunk/block.c
===================================================================
--- trunk/block.c 2009-03-11 20:16:16 UTC (rev 6821)
+++ trunk/block.c 2009-03-12 19:57:08 UTC (rev 6822)
@@ -1675,3 +1675,25 @@
return drv->bdrv_ioctl(bs, req, buf);
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);
+}
Modified: trunk/block.h
===================================================================
--- trunk/block.h 2009-03-11 20:16:16 UTC (rev 6821)
+++ trunk/block.h 2009-03-12 19:57:08 UTC (rev 6822)
@@ -101,6 +101,14 @@
BlockDriverCompletionFunc *cb, void *opaque);
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. */
void bdrv_flush(BlockDriverState *bs);
void bdrv_flush_all(void);
Modified: trunk/hw/scsi-generic.c
===================================================================
--- trunk/hw/scsi-generic.c 2009-03-11 20:16:16 UTC (rev 6821)
+++ trunk/hw/scsi-generic.c 2009-03-12 19:57:08 UTC (rev 6822)
@@ -201,6 +201,7 @@
SCSIRequest *r, int direction,
BlockDriverCompletionFunc *complete)
{
+ int ret;
r->io_header.interface_id = 'S';
r->io_header.dxfer_direction = direction;
@@ -214,25 +215,27 @@
r->io_header.usr_ptr = r;
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);
return -1;
}
if (complete == NULL) {
int ret;
r->aiocb = NULL;
- while ((ret = bdrv_pread(bdrv, -1, &r->io_header,
- sizeof(r->io_header))) == -1 &&
- errno == EINTR);
- if (ret == -1) {
+ while ((ret = bdrv_sg_recv_response(bdrv, &r->io_header,
+ sizeof(r->io_header))) < 0 &&
+ ret == -EINTR)
+ ;
+ if (ret < 0) {
BADF("execute_command: read failed !\n");
return -1;
}
return 0;
}
- r->aiocb = bdrv_aio_read(bdrv, 0, (uint8_t*)&r->io_header,
- -(int64_t)sizeof(r->io_header), complete, r);
+ r->aiocb = bdrv_sg_aio_read(bdrv, (uint8_t*)&r->io_header,
+ sizeof(r->io_header), complete, r);
if (r->aiocb == NULL) {
BADF("execute_command: read failed !\n");
return -1;
@@ -634,14 +637,15 @@
io_header.sbp = sensebuf;
io_header.timeout = 6000; /* XXX */
- ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header));
- if (ret == -1)
+ ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header));
+ if (ret < 0)
return -1;
- while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 &&
- errno == EINTR);
+ while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header)))
< 0 &&
+ ret == -EINTR)
+ ;
- if (ret == -1)
+ if (ret < 0)
return -1;
return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
@@ -671,14 +675,15 @@
io_header.sbp = sensebuf;
io_header.timeout = 6000; /* XXX */
- ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header));
- if (ret == -1)
+ ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header));
+ if (ret < 0)
return -1;
- while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 &&
- errno == EINTR);
+ while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header)))
< 0 &&
+ ret == -EINTR)
+ ;
- if (ret == -1)
+ if (ret < 0)
return -1;
return (buf[9] << 16) | (buf[10] << 8) | buf[11];
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