From 221f715d90ec5fec569a19119887445c037bca86 Mon Sep 17 00:00:00 2001 From: aliguori Date: Sat, 28 Mar 2009 17:28:41 +0000 Subject: [PATCH] new scsi-generic abstraction, use SG_IO (Christoph Hellwig) Okay, I started looking into how to handle scsi-generic I/O in the new world order. I think the best is to use the SG_IO ioctl instead of the read/write interface as that allows us to support scsi passthrough on disk/cdrom devices, too. See Hannes patch on the kvm list from August for an example. Now that we always do ioctls we don't need another abstraction than bdrv_ioctl for the synchronous requests for now, and for asynchronous requests I've added a aio_ioctl abstraction keeping it simple. Long-term we might want to move the ops to a higher-level abstraction and let the low-level code fill out the request header, but I'm lazy enough to leave that to the people trying to support scsi-passthrough on a non-Linux OS. Tested lightly by issuing various sg_ commands from sg3-utils in a guest to a host CDROM device. Signed-off-by: Christoph Hellwig Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6895 c046a42c-6fe2-441c-8c8c-71466251a162 --- block-raw-posix.c | 54 ++++++++++++------------ block.c | 25 ++++-------- block.h | 11 ++--- block_int.h | 13 ++---- hw/scsi-generic.c | 42 ++----------------- posix-aio-compat.c | 100 ++++++++++++++++++++++++++++++--------------- posix-aio-compat.h | 7 +++- 7 files changed, 115 insertions(+), 137 deletions(-) diff --git a/block-raw-posix.c b/block-raw-posix.c index be6dd8333f..b35c9d09b2 100644 --- a/block-raw-posix.c +++ b/block-raw-posix.c @@ -1209,6 +1209,26 @@ static int raw_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) return ioctl(s->fd, req, buf); } + +static BlockDriverAIOCB *raw_aio_ioctl(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque) +{ + RawAIOCB *acb; + + acb = raw_aio_setup(bs, 0, buf, 0, cb, opaque); + if (!acb) + return NULL; + + acb->aiocb.aio_ioctl_cmd = req; + if (qemu_paio_ioctl(&acb->aiocb) < 0) { + raw_aio_remove(acb); + return NULL; + } + + return &acb->common; +} + #elif defined(__FreeBSD__) static int fd_open(BlockDriverState *bs) @@ -1349,33 +1369,14 @@ static int raw_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { return -ENOTSUP; } -#endif /* !linux && !FreeBSD */ - -static int raw_sg_send_command(BlockDriverState *bs, void *buf, int count) -{ - return raw_pwrite(bs, -1, buf, count); -} - -static int raw_sg_recv_response(BlockDriverState *bs, void *buf, int count) -{ - return raw_pread(bs, -1, buf, count); -} - -static BlockDriverAIOCB *raw_sg_aio_read(BlockDriverState *bs, - void *buf, int count, - BlockDriverCompletionFunc *cb, - void *opaque) -{ - return raw_aio_read(bs, 0, buf, -(int64_t)count, cb, opaque); -} -static BlockDriverAIOCB *raw_sg_aio_write(BlockDriverState *bs, - void *buf, int count, - BlockDriverCompletionFunc *cb, - void *opaque) +static BlockDriverAIOCB *raw_aio_ioctl(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque) { - return raw_aio_write(bs, 0, buf, -(int64_t)count, cb, opaque); + return -ENOTSUP; } +#endif /* !linux && !FreeBSD */ BlockDriver bdrv_host_device = { .format_name = "host_device", @@ -1402,8 +1403,5 @@ BlockDriver bdrv_host_device = { .bdrv_set_locked = raw_set_locked, /* generic scsi device */ .bdrv_ioctl = raw_ioctl, - .bdrv_sg_send_command = raw_sg_send_command, - .bdrv_sg_recv_response = raw_sg_recv_response, - .bdrv_sg_aio_read = raw_sg_aio_read, - .bdrv_sg_aio_write = raw_sg_aio_write, + .bdrv_aio_ioctl = raw_aio_ioctl, }; diff --git a/block.c b/block.c index 6479072e9b..7230f04e40 100644 --- a/block.c +++ b/block.c @@ -1633,24 +1633,13 @@ int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) return -ENOTSUP; } -int bdrv_sg_send_command(BlockDriverState *bs, void *buf, int count) -{ - return bs->drv->bdrv_sg_send_command(bs, buf, count); -} - -int bdrv_sg_recv_response(BlockDriverState *bs, void *buf, int count) -{ - return bs->drv->bdrv_sg_recv_response(bs, buf, count); -} - -BlockDriverAIOCB *bdrv_sg_aio_read(BlockDriverState *bs, void *buf, int count, - BlockDriverCompletionFunc *cb, void *opaque) +BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque) { - return bs->drv->bdrv_sg_aio_read(bs, buf, count, cb, opaque); -} + BlockDriver *drv = bs->drv; -BlockDriverAIOCB *bdrv_sg_aio_write(BlockDriverState *bs, void *buf, int count, - BlockDriverCompletionFunc *cb, void *opaque) -{ - return bs->drv->bdrv_sg_aio_write(bs, buf, count, cb, opaque); + if (drv && drv->bdrv_aio_ioctl) + return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); + return NULL; } diff --git a/block.h b/block.h index b0c63ac588..750816e55d 100644 --- a/block.h +++ b/block.h @@ -102,12 +102,10 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num, 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); +int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf); +BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque); /* Ensure contents are flushed to disk. */ void bdrv_flush(BlockDriverState *bs); @@ -169,7 +167,6 @@ int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn); -int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf); char *get_human_readable_size(char *buf, int buf_size, int64_t size); int path_is_absolute(const char *path); diff --git a/block_int.h b/block_int.h index 8b4c5fe5fc..b45bde04d4 100644 --- a/block_int.h +++ b/block_int.h @@ -86,16 +86,9 @@ struct BlockDriver { /* to control generic scsi devices */ int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); - 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); + BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque); AIOPool aio_pool; struct BlockDriver *next; diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c index 53e8951270..f4c615b626 100644 --- a/hw/scsi-generic.c +++ b/hw/scsi-generic.c @@ -201,8 +201,6 @@ static int execute_command(BlockDriverState *bdrv, SCSIRequest *r, int direction, BlockDriverCompletionFunc *complete) { - int ret; - r->io_header.interface_id = 'S'; r->io_header.dxfer_direction = direction; r->io_header.dxferp = r->buf; @@ -215,27 +213,7 @@ static int execute_command(BlockDriverState *bdrv, r->io_header.usr_ptr = r; r->io_header.flags |= SG_FLAG_DIRECT_IO; - 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_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_sg_aio_read(bdrv, (uint8_t*)&r->io_header, - sizeof(r->io_header), complete, r); + r->aiocb = bdrv_aio_ioctl(bdrv, SG_IO, &r->io_header, complete, r); if (r->aiocb == NULL) { BADF("execute_command: read failed !\n"); return -1; @@ -637,14 +615,7 @@ static int get_blocksize(BlockDriverState *bdrv) io_header.sbp = sensebuf; io_header.timeout = 6000; /* XXX */ - ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header)); - if (ret < 0) - return -1; - - while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 && - ret == -EINTR) - ; - + ret = bdrv_ioctl(bdrv, SG_IO, &io_header); if (ret < 0) return -1; @@ -675,14 +646,7 @@ static int get_stream_blocksize(BlockDriverState *bdrv) io_header.sbp = sensebuf; io_header.timeout = 6000; /* XXX */ - ret = bdrv_sg_send_command(bdrv, &io_header, sizeof(io_header)); - if (ret < 0) - return -1; - - while ((ret = bdrv_sg_recv_response(bdrv, &io_header, sizeof(io_header))) < 0 && - ret == -EINTR) - ; - + ret = bdrv_ioctl(bdrv, SG_IO, &io_header); if (ret < 0) return -1; diff --git a/posix-aio-compat.c b/posix-aio-compat.c index 6b547f41fd..65c80ecc3e 100644 --- a/posix-aio-compat.c +++ b/posix-aio-compat.c @@ -11,6 +11,7 @@ * */ +#include #include #include #include @@ -75,6 +76,47 @@ static void thread_create(pthread_t *thread, pthread_attr_t *attr, if (ret) die2(ret, "pthread_create"); } +static size_t handle_aiocb_readwrite(struct qemu_paiocb *aiocb) +{ + size_t offset = 0; + ssize_t len; + + while (offset < aiocb->aio_nbytes) { + if (aiocb->aio_type == QEMU_PAIO_WRITE) + len = pwrite(aiocb->aio_fildes, + (const char *)aiocb->aio_buf + offset, + aiocb->aio_nbytes - offset, + aiocb->aio_offset + offset); + else + len = pread(aiocb->aio_fildes, + (char *)aiocb->aio_buf + offset, + aiocb->aio_nbytes - offset, + aiocb->aio_offset + offset); + + if (len == -1 && errno == EINTR) + continue; + else if (len == -1) { + offset = -errno; + break; + } else if (len == 0) + break; + + offset += len; + } + + return offset; +} + +static size_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb) +{ + int ret; + + ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_buf); + if (ret == -1) + return -errno; + return ret; +} + static void *aio_thread(void *unused) { pid_t pid; @@ -88,8 +130,7 @@ static void *aio_thread(void *unused) while (1) { struct qemu_paiocb *aiocb; - size_t offset; - int ret = 0; + size_t ret = 0; qemu_timeval tv; struct timespec ts; @@ -109,40 +150,26 @@ static void *aio_thread(void *unused) aiocb = TAILQ_FIRST(&request_list); TAILQ_REMOVE(&request_list, aiocb, node); - - offset = 0; aiocb->active = 1; - idle_threads--; mutex_unlock(&lock); - while (offset < aiocb->aio_nbytes) { - ssize_t len; - - if (aiocb->is_write) - len = pwrite(aiocb->aio_fildes, - (const char *)aiocb->aio_buf + offset, - aiocb->aio_nbytes - offset, - aiocb->aio_offset + offset); - else - len = pread(aiocb->aio_fildes, - (char *)aiocb->aio_buf + offset, - aiocb->aio_nbytes - offset, - aiocb->aio_offset + offset); - - if (len == -1 && errno == EINTR) - continue; - else if (len == -1) { - offset = -errno; - break; - } else if (len == 0) - break; - - offset += len; - } + switch (aiocb->aio_type) { + case QEMU_PAIO_READ: + case QEMU_PAIO_WRITE: + ret = handle_aiocb_readwrite(aiocb); + break; + case QEMU_PAIO_IOCTL: + ret = handle_aiocb_ioctl(aiocb); + break; + default: + fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type); + ret = -EINVAL; + break; + } mutex_lock(&lock); - aiocb->ret = offset; + aiocb->ret = ret; idle_threads++; mutex_unlock(&lock); @@ -178,9 +205,9 @@ int qemu_paio_init(struct qemu_paioinit *aioinit) return 0; } -static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write) +static int qemu_paio_submit(struct qemu_paiocb *aiocb, int type) { - aiocb->is_write = is_write; + aiocb->aio_type = type; aiocb->ret = -EINPROGRESS; aiocb->active = 0; mutex_lock(&lock); @@ -195,12 +222,17 @@ static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write) int qemu_paio_read(struct qemu_paiocb *aiocb) { - return qemu_paio_submit(aiocb, 0); + return qemu_paio_submit(aiocb, QEMU_PAIO_READ); } int qemu_paio_write(struct qemu_paiocb *aiocb) { - return qemu_paio_submit(aiocb, 1); + return qemu_paio_submit(aiocb, QEMU_PAIO_WRITE); +} + +int qemu_paio_ioctl(struct qemu_paiocb *aiocb) +{ + return qemu_paio_submit(aiocb, QEMU_PAIO_IOCTL); } ssize_t qemu_paio_return(struct qemu_paiocb *aiocb) diff --git a/posix-aio-compat.h b/posix-aio-compat.h index 0bc10f5e08..a1cdfd7f1f 100644 --- a/posix-aio-compat.h +++ b/posix-aio-compat.h @@ -29,12 +29,16 @@ struct qemu_paiocb int aio_fildes; void *aio_buf; size_t aio_nbytes; +#define aio_ioctl_cmd aio_nbytes /* for QEMU_PAIO_IOCTL */ int ev_signo; off_t aio_offset; /* private */ TAILQ_ENTRY(qemu_paiocb) node; - int is_write; + int aio_type; +#define QEMU_PAIO_READ 0x01 +#define QEMU_PAIO_WRITE 0x02 +#define QEMU_PAIO_IOCTL 0x03 ssize_t ret; int active; }; @@ -49,6 +53,7 @@ struct qemu_paioinit int qemu_paio_init(struct qemu_paioinit *aioinit); int qemu_paio_read(struct qemu_paiocb *aiocb); int qemu_paio_write(struct qemu_paiocb *aiocb); +int qemu_paio_ioctl(struct qemu_paiocb *aiocb); int qemu_paio_error(struct qemu_paiocb *aiocb); ssize_t qemu_paio_return(struct qemu_paiocb *aiocb); int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb); -- 2.39.2