RBD: Add support readv,writev for rbd

Rbd can do readv and writev directly, so wo do not need to transform
iov to buf or vice versa any more.

Signed-off-by: tianqing <tianqing@unitedstack.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
This commit is contained in:
tianqing 2017-02-21 14:50:03 +08:00 committed by Jeff Cody
parent ef503a8417
commit 1d393bdeae

View file

@ -62,6 +62,13 @@
#define RBD_MAX_SNAP_NAME_SIZE 128
#define RBD_MAX_SNAPS 100
/* The LIBRBD_SUPPORTS_IOVEC is defined in librbd.h */
#ifdef LIBRBD_SUPPORTS_IOVEC
#define LIBRBD_USE_IOVEC 1
#else
#define LIBRBD_USE_IOVEC 0
#endif
typedef enum {
RBD_AIO_READ,
RBD_AIO_WRITE,
@ -310,6 +317,17 @@ static int qemu_rbd_set_conf(rados_t cluster, const char *conf,
return ret;
}
static void qemu_rbd_memset(RADOSCB *rcb, int64_t offs)
{
if (LIBRBD_USE_IOVEC) {
RBDAIOCB *acb = rcb->acb;
iov_memset(acb->qiov->iov, acb->qiov->niov, offs, 0,
acb->qiov->size - offs);
} else {
memset(rcb->buf + offs, 0, rcb->size - offs);
}
}
static int qemu_rbd_create(const char *filename, QemuOpts *opts, Error **errp)
{
Error *local_err = NULL;
@ -426,11 +444,11 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
}
} else {
if (r < 0) {
memset(rcb->buf, 0, rcb->size);
qemu_rbd_memset(rcb, 0);
acb->ret = r;
acb->error = 1;
} else if (r < rcb->size) {
memset(rcb->buf + r, 0, rcb->size - r);
qemu_rbd_memset(rcb, r);
if (!acb->error) {
acb->ret = rcb->size;
}
@ -441,10 +459,13 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb)
g_free(rcb);
if (acb->cmd == RBD_AIO_READ) {
qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
if (!LIBRBD_USE_IOVEC) {
if (acb->cmd == RBD_AIO_READ) {
qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
}
qemu_vfree(acb->bounce);
}
qemu_vfree(acb->bounce);
acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));
qemu_aio_unref(acb);
@ -655,7 +676,6 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
RBDAIOCB *acb;
RADOSCB *rcb = NULL;
rbd_completion_t c;
char *buf;
int r;
BDRVRBDState *s = bs->opaque;
@ -664,27 +684,29 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
acb->cmd = cmd;
acb->qiov = qiov;
assert(!qiov || qiov->size == size);
if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
acb->bounce = NULL;
} else {
acb->bounce = qemu_try_blockalign(bs, qiov->size);
if (acb->bounce == NULL) {
goto failed;
rcb = g_new(RADOSCB, 1);
if (!LIBRBD_USE_IOVEC) {
if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) {
acb->bounce = NULL;
} else {
acb->bounce = qemu_try_blockalign(bs, qiov->size);
if (acb->bounce == NULL) {
goto failed;
}
}
if (cmd == RBD_AIO_WRITE) {
qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
}
rcb->buf = acb->bounce;
}
acb->ret = 0;
acb->error = 0;
acb->s = s;
if (cmd == RBD_AIO_WRITE) {
qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
}
buf = acb->bounce;
rcb = g_new(RADOSCB, 1);
rcb->acb = acb;
rcb->buf = buf;
rcb->s = acb->s;
rcb->size = size;
r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c);
@ -694,10 +716,18 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
switch (cmd) {
case RBD_AIO_WRITE:
r = rbd_aio_write(s->image, off, size, buf, c);
#ifdef LIBRBD_SUPPORTS_IOVEC
r = rbd_aio_writev(s->image, qiov->iov, qiov->niov, off, c);
#else
r = rbd_aio_write(s->image, off, size, rcb->buf, c);
#endif
break;
case RBD_AIO_READ:
r = rbd_aio_read(s->image, off, size, buf, c);
#ifdef LIBRBD_SUPPORTS_IOVEC
r = rbd_aio_readv(s->image, qiov->iov, qiov->niov, off, c);
#else
r = rbd_aio_read(s->image, off, size, rcb->buf, c);
#endif
break;
case RBD_AIO_DISCARD:
r = rbd_aio_discard_wrapper(s->image, off, size, c);
@ -712,14 +742,16 @@ static BlockAIOCB *rbd_start_aio(BlockDriverState *bs,
if (r < 0) {
goto failed_completion;
}
return &acb->common;
failed_completion:
rbd_aio_release(c);
failed:
g_free(rcb);
qemu_vfree(acb->bounce);
if (!LIBRBD_USE_IOVEC) {
qemu_vfree(acb->bounce);
}
qemu_aio_unref(acb);
return NULL;
}