Commit 7d78066926b68afe28a1948c64618ee085d9ab02
1 parent
943984c7
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 <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6822 c046a42c-6fe2-441c-8c8c-71466251a162
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3 changed files
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52 additions
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17 deletions
block.c
@@ -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) | ||
1675 | return drv->bdrv_ioctl(bs, req, buf); | 1675 | return drv->bdrv_ioctl(bs, req, buf); |
1676 | return -ENOTSUP; | 1676 | return -ENOTSUP; |
1677 | } | 1677 | } |
1678 | + | ||
1679 | +int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count) | ||
1680 | +{ | ||
1681 | + return bdrv_pwrite(bs, -1, buf, count); | ||
1682 | +} | ||
1683 | + | ||
1684 | +int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count) | ||
1685 | +{ | ||
1686 | + return bdrv_pread(bs, -1, buf, count); | ||
1687 | +} | ||
1688 | + | ||
1689 | +BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count, | ||
1690 | + BlockDriverCompletionFunc *cb, void *opaque) | ||
1691 | +{ | ||
1692 | + return bdrv_aio_read(bs, 0, buf, -(int64_t)count, cb, opaque); | ||
1693 | +} | ||
1694 | + | ||
1695 | +BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count, | ||
1696 | + BlockDriverCompletionFunc *cb, void *opaque) | ||
1697 | +{ | ||
1698 | + return bdrv_aio_write(bs, 0, buf, -(int64_t)count, cb, opaque); | ||
1699 | +} |
block.h
@@ -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, | ||
101 | BlockDriverCompletionFunc *cb, void *opaque); | 101 | BlockDriverCompletionFunc *cb, void *opaque); |
102 | void bdrv_aio_cancel(BlockDriverAIOCB *acb); | 102 | void bdrv_aio_cancel(BlockDriverAIOCB *acb); |
103 | 103 | ||
104 | +/* sg packet commands */ | ||
105 | +int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count); | ||
106 | +int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count); | ||
107 | +BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count, | ||
108 | + BlockDriverCompletionFunc *cb, void *opaque); | ||
109 | +BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count, | ||
110 | + BlockDriverCompletionFunc *cb, void *opaque); | ||
111 | + | ||
104 | /* Ensure contents are flushed to disk. */ | 112 | /* Ensure contents are flushed to disk. */ |
105 | void bdrv_flush(BlockDriverState *bs); | 113 | void bdrv_flush(BlockDriverState *bs); |
106 | void bdrv_flush_all(void); | 114 | void bdrv_flush_all(void); |
hw/scsi-generic.c
@@ -201,6 +201,7 @@ static int execute_command(BlockDriverState *bdrv, | @@ -201,6 +201,7 @@ static int execute_command(BlockDriverState *bdrv, | ||
201 | SCSIRequest *r, int direction, | 201 | SCSIRequest *r, int direction, |
202 | BlockDriverCompletionFunc *complete) | 202 | BlockDriverCompletionFunc *complete) |
203 | { | 203 | { |
204 | + int ret; | ||
204 | 205 | ||
205 | r->io_header.interface_id = 'S'; | 206 | r->io_header.interface_id = 'S'; |
206 | r->io_header.dxfer_direction = direction; | 207 | 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, | ||
214 | r->io_header.usr_ptr = r; | 215 | r->io_header.usr_ptr = r; |
215 | r->io_header.flags |= SG_FLAG_DIRECT_IO; | 216 | r->io_header.flags |= SG_FLAG_DIRECT_IO; |
216 | 217 | ||
217 | - if (bdrv_pwrite(bdrv, -1, &r->io_header, sizeof(r->io_header)) == -1) { | 218 | + ret = bdrv_sg_send_command(bdrv, &r->io_header, sizeof(r->io_header)); |
219 | + if (ret < 0) { | ||
218 | BADF("execute_command: write failed ! (%d)\n", errno); | 220 | BADF("execute_command: write failed ! (%d)\n", errno); |
219 | return -1; | 221 | return -1; |
220 | } | 222 | } |
221 | if (complete == NULL) { | 223 | if (complete == NULL) { |
222 | int ret; | 224 | int ret; |
223 | r->aiocb = NULL; | 225 | r->aiocb = NULL; |
224 | - while ((ret = bdrv_pread(bdrv, -1, &r->io_header, | ||
225 | - sizeof(r->io_header))) == -1 && | ||
226 | - errno == EINTR); | ||
227 | - if (ret == -1) { | 226 | + while ((ret = bdrv_sg_recv_response(bdrv, &r->io_header, |
227 | + sizeof(r->io_header))) < 0 && | ||
228 | + ret == -EINTR) | ||
229 | + ; | ||
230 | + if (ret < 0) { | ||
228 | BADF("execute_command: read failed !\n"); | 231 | BADF("execute_command: read failed !\n"); |
229 | return -1; | 232 | return -1; |
230 | } | 233 | } |
231 | return 0; | 234 | return 0; |
232 | } | 235 | } |
233 | 236 | ||
234 | - r->aiocb = bdrv_aio_read(bdrv, 0, (uint8_t*)&r->io_header, | ||
235 | - -(int64_t)sizeof(r->io_header), complete, r); | 237 | + r->aiocb = bdrv_sg_aio_read(bdrv, (uint8_t*)&r->io_header, |
238 | + sizeof(r->io_header), complete, r); | ||
236 | if (r->aiocb == NULL) { | 239 | if (r->aiocb == NULL) { |
237 | BADF("execute_command: read failed !\n"); | 240 | BADF("execute_command: read failed !\n"); |
238 | return -1; | 241 | return -1; |
@@ -634,14 +637,15 @@ static int get_blocksize(BlockDriverState *bdrv) | @@ -634,14 +637,15 @@ static int get_blocksize(BlockDriverState *bdrv) | ||
634 | io_header.sbp = sensebuf; | 637 | io_header.sbp = sensebuf; |
635 | io_header.timeout = 6000; /* XXX */ | 638 | io_header.timeout = 6000; /* XXX */ |
636 | 639 | ||
637 | - ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header)); | ||
638 | - if (ret == -1) | 640 | + ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header)); |
641 | + if (ret < 0) | ||
639 | return -1; | 642 | return -1; |
640 | 643 | ||
641 | - while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 && | ||
642 | - errno == EINTR); | 644 | + while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 && |
645 | + ret == -EINTR) | ||
646 | + ; | ||
643 | 647 | ||
644 | - if (ret == -1) | 648 | + if (ret < 0) |
645 | return -1; | 649 | return -1; |
646 | 650 | ||
647 | return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7]; | 651 | 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) | ||
671 | io_header.sbp = sensebuf; | 675 | io_header.sbp = sensebuf; |
672 | io_header.timeout = 6000; /* XXX */ | 676 | io_header.timeout = 6000; /* XXX */ |
673 | 677 | ||
674 | - ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header)); | ||
675 | - if (ret == -1) | 678 | + ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header)); |
679 | + if (ret < 0) | ||
676 | return -1; | 680 | return -1; |
677 | 681 | ||
678 | - while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 && | ||
679 | - errno == EINTR); | 682 | + while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 && |
683 | + ret == -EINTR) | ||
684 | + ; | ||
680 | 685 | ||
681 | - if (ret == -1) | 686 | + if (ret < 0) |
682 | return -1; | 687 | return -1; |
683 | 688 | ||
684 | return (buf[9] << 16) | (buf[10] << 8) | buf[11]; | 689 | return (buf[9] << 16) | (buf[10] << 8) | buf[11]; |