Message ID | 1409274040-20304-1-git-send-email-famz@redhat.com |
---|---|
State | New |
Headers | show |
The Friday 29 Aug 2014 à 09:00:40 (+0800), Fam Zheng wrote : > This is an analogue to Linux null_blk. It can be used for testing or > benchmarking block device emulation and general block layer > functionalities such as coroutines and throttling, where disk IO is not > necessary or wanted. > > Use null:// for AIO version, and null-co:// for coroutine version. > > Signed-off-by: Fam Zheng <famz@redhat.com> > > --- > V4: Add "#optional". (Eric) > Add null_aio_common. (Benoit) > Add null-co in json schema. (Eric, Benoit) > --- > block/Makefile.objs | 1 + > block/null.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++ > qapi/block-core.json | 20 +++++- > 3 files changed, 195 insertions(+), 2 deletions(-) > create mode 100644 block/null.c > > diff --git a/block/Makefile.objs b/block/Makefile.objs > index 858d2b3..087e281 100644 > --- a/block/Makefile.objs > +++ b/block/Makefile.objs > @@ -9,6 +9,7 @@ block-obj-y += snapshot.o qapi.o > block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o > block-obj-$(CONFIG_POSIX) += raw-posix.o > block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o > +block-obj-y += null.o > > ifeq ($(CONFIG_POSIX),y) > block-obj-y += nbd.o nbd-client.o sheepdog.o > diff --git a/block/null.c b/block/null.c > new file mode 100644 > index 0000000..5676994 > --- /dev/null > +++ b/block/null.c > @@ -0,0 +1,176 @@ > +/* > + * Null block driver > + * > + * Authors: > + * Fam Zheng <famz@redhat.com> > + * > + * Copyright (C) 2014 Red Hat, Inc. > + * > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > + * See the COPYING file in the top-level directory. > + */ > + > +#include "block/block_int.h" > + > +typedef struct { > + int64_t length; > +} BDRVNullState; > + > +static QemuOptsList runtime_opts = { > + .name = "null", > + .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), > + .desc = { > + { > + .name = "filename", > + .type = QEMU_OPT_STRING, > + .help = "", > + }, > + { > + .name = BLOCK_OPT_SIZE, > + .type = QEMU_OPT_SIZE, > + .help = "size of the null block", > + }, > + { /* end of list */ } > + }, > +}; > + > +static int null_file_open(BlockDriverState *bs, QDict *options, int flags, > + Error **errp) > +{ > + QemuOpts *opts; > + BDRVNullState *s = bs->opaque; > + > + opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); > + qemu_opts_absorb_qdict(opts, options, &error_abort); > + s->length = > + qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 1 << 30); > + qemu_opts_del(opts); > + return 0; > +} > + > +static void null_close(BlockDriverState *bs) > +{ > +} > + > +static int64_t null_getlength(BlockDriverState *bs) > +{ > + BDRVNullState *s = bs->opaque; > + return s->length; > +} > + > +static coroutine_fn int null_co_read(BlockDriverState *bs, int64_t sector_num, > + uint8_t *buf, int nb_sectors) > +{ > + return 0; > +} > + > +static coroutine_fn int null_co_write(BlockDriverState *bs, int64_t sector_num, > + const uint8_t *buf, int nb_sectors) > +{ > + return 0; > +} > + > +static coroutine_fn int null_co_flush(BlockDriverState *bs) > +{ > + return 0; > +} > + > +typedef struct { > + BlockDriverAIOCB common; > + QEMUBH *bh; > +} NullAIOCB; > + > +static void null_aio_cancel(BlockDriverAIOCB *blockacb); > + > +static const AIOCBInfo null_aiocb_info = { > + .aiocb_size = sizeof(NullAIOCB), > + .cancel = null_aio_cancel, > +}; > + > +static void null_bh_cb(void *opaque) > +{ > + NullAIOCB *acb = opaque; > + acb->common.cb(acb->common.opaque, 0); > + qemu_bh_delete(acb->bh); > + qemu_aio_release(acb); > +} > + > +static inline BlockDriverAIOCB *null_aio_common(BlockDriverState *bs, > + BlockDriverCompletionFunc *cb, > + void *opaque) > +{ > + NullAIOCB *acb; > + > + acb = qemu_aio_get(&null_aiocb_info, bs, cb, opaque); > + acb->bh = aio_bh_new(bdrv_get_aio_context(bs), null_bh_cb, acb); > + qemu_bh_schedule(acb->bh); > + return &acb->common; > +} > + > +static BlockDriverAIOCB *null_aio_readv(BlockDriverState *bs, > + int64_t sector_num, QEMUIOVector *qiov, > + int nb_sectors, > + BlockDriverCompletionFunc *cb, > + void *opaque) > +{ > + return null_aio_common(bs, cb, opaque); > +} > + > +static BlockDriverAIOCB *null_aio_writev(BlockDriverState *bs, > + int64_t sector_num, QEMUIOVector *qiov, > + int nb_sectors, > + BlockDriverCompletionFunc *cb, > + void *opaque) > +{ > + return null_aio_common(bs, cb, opaque); > +} > + > +static BlockDriverAIOCB *null_aio_flush(BlockDriverState *bs, > + BlockDriverCompletionFunc *cb, > + void *opaque) > +{ > + return null_aio_common(bs, cb, opaque); > +} > + > +static void null_aio_cancel(BlockDriverAIOCB *blockacb) > +{ > + NullAIOCB *acb = container_of(blockacb, NullAIOCB, common); > + qemu_bh_delete(acb->bh); > + qemu_aio_release(acb); > +} > + > +static BlockDriver bdrv_null = { > + .format_name = "null", > + .protocol_name = "null", > + .instance_size = sizeof(BDRVNullState), > + > + .bdrv_file_open = null_file_open, > + .bdrv_close = null_close, > + .bdrv_getlength = null_getlength, > + > + .bdrv_aio_readv = null_aio_readv, > + .bdrv_aio_writev = null_aio_writev, > + .bdrv_aio_flush = null_aio_flush, > +}; > + > +static BlockDriver bdrv_null_co = { > + .format_name = "null-co", > + .protocol_name = "null-co", > + .instance_size = sizeof(BDRVNullState), > + > + .bdrv_file_open = null_file_open, > + .bdrv_close = null_close, > + .bdrv_getlength = null_getlength, > + > + .bdrv_read = null_co_read, > + .bdrv_write = null_co_write, > + .bdrv_co_flush_to_disk = null_co_flush, > +}; > + > +static void bdrv_null_init(void) > +{ > + bdrv_register(&bdrv_null); > + bdrv_register(&bdrv_null_co); > +} > + > +block_init(bdrv_null_init); > diff --git a/qapi/block-core.json b/qapi/block-core.json > index fb74c56..92e294c 100644 > --- a/qapi/block-core.json > +++ b/qapi/block-core.json > @@ -1150,7 +1150,8 @@ > 'data': [ 'archipelago', 'file', 'host_device', 'host_cdrom', 'host_floppy', > 'http', 'https', 'ftp', 'ftps', 'tftp', 'vvfat', 'blkdebug', > 'blkverify', 'bochs', 'cloop', 'cow', 'dmg', 'parallels', 'qcow', > - 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum' ] } > + 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum', > + 'null', 'null-co' ] } > > ## > # @BlockdevOptionsBase > @@ -1203,6 +1204,19 @@ > 'data': { 'filename': 'str' } } > > ## > +# @BlockdevOptionsNull > +# > +# Driver specific block device options for the null backend. > +# > +# @size: #optional size of the device in bytes. > +# > +# Since: 2.2 > +## > +{ 'type': 'BlockdevOptionsNull', > + 'base': 'BlockdevOptionsFile', > + 'data': { '*size': 'int' } } > + > +## > # @BlockdevOptionsVVFAT > # > # Driver specific block device options for the vvfat protocol. > @@ -1484,7 +1498,9 @@ > 'vhdx': 'BlockdevOptionsGenericFormat', > 'vmdk': 'BlockdevOptionsGenericCOWFormat', > 'vpc': 'BlockdevOptionsGenericFormat', > - 'quorum': 'BlockdevOptionsQuorum' > + 'quorum': 'BlockdevOptionsQuorum', > + 'null': 'BlockdevOptionsNull', > + 'null-co': 'BlockdevOptionsNull' > } } > > ## > -- > 2.1.0 > Look good. Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
On Fri, Aug 29, 2014 at 09:00:40AM +0800, Fam Zheng wrote: > This is an analogue to Linux null_blk. It can be used for testing or > benchmarking block device emulation and general block layer > functionalities such as coroutines and throttling, where disk IO is not > necessary or wanted. > > Use null:// for AIO version, and null-co:// for coroutine version. Looks fine but please call them null-aio:// and null-co:// so it's 100% clear what they do. Stefan
diff --git a/block/Makefile.objs b/block/Makefile.objs index 858d2b3..087e281 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -9,6 +9,7 @@ block-obj-y += snapshot.o qapi.o block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o block-obj-$(CONFIG_POSIX) += raw-posix.o block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o +block-obj-y += null.o ifeq ($(CONFIG_POSIX),y) block-obj-y += nbd.o nbd-client.o sheepdog.o diff --git a/block/null.c b/block/null.c new file mode 100644 index 0000000..5676994 --- /dev/null +++ b/block/null.c @@ -0,0 +1,176 @@ +/* + * Null block driver + * + * Authors: + * Fam Zheng <famz@redhat.com> + * + * Copyright (C) 2014 Red Hat, Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "block/block_int.h" + +typedef struct { + int64_t length; +} BDRVNullState; + +static QemuOptsList runtime_opts = { + .name = "null", + .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), + .desc = { + { + .name = "filename", + .type = QEMU_OPT_STRING, + .help = "", + }, + { + .name = BLOCK_OPT_SIZE, + .type = QEMU_OPT_SIZE, + .help = "size of the null block", + }, + { /* end of list */ } + }, +}; + +static int null_file_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + QemuOpts *opts; + BDRVNullState *s = bs->opaque; + + opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); + qemu_opts_absorb_qdict(opts, options, &error_abort); + s->length = + qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 1 << 30); + qemu_opts_del(opts); + return 0; +} + +static void null_close(BlockDriverState *bs) +{ +} + +static int64_t null_getlength(BlockDriverState *bs) +{ + BDRVNullState *s = bs->opaque; + return s->length; +} + +static coroutine_fn int null_co_read(BlockDriverState *bs, int64_t sector_num, + uint8_t *buf, int nb_sectors) +{ + return 0; +} + +static coroutine_fn int null_co_write(BlockDriverState *bs, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + return 0; +} + +static coroutine_fn int null_co_flush(BlockDriverState *bs) +{ + return 0; +} + +typedef struct { + BlockDriverAIOCB common; + QEMUBH *bh; +} NullAIOCB; + +static void null_aio_cancel(BlockDriverAIOCB *blockacb); + +static const AIOCBInfo null_aiocb_info = { + .aiocb_size = sizeof(NullAIOCB), + .cancel = null_aio_cancel, +}; + +static void null_bh_cb(void *opaque) +{ + NullAIOCB *acb = opaque; + acb->common.cb(acb->common.opaque, 0); + qemu_bh_delete(acb->bh); + qemu_aio_release(acb); +} + +static inline BlockDriverAIOCB *null_aio_common(BlockDriverState *bs, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + NullAIOCB *acb; + + acb = qemu_aio_get(&null_aiocb_info, bs, cb, opaque); + acb->bh = aio_bh_new(bdrv_get_aio_context(bs), null_bh_cb, acb); + qemu_bh_schedule(acb->bh); + return &acb->common; +} + +static BlockDriverAIOCB *null_aio_readv(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, + int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + return null_aio_common(bs, cb, opaque); +} + +static BlockDriverAIOCB *null_aio_writev(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, + int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + return null_aio_common(bs, cb, opaque); +} + +static BlockDriverAIOCB *null_aio_flush(BlockDriverState *bs, + BlockDriverCompletionFunc *cb, + void *opaque) +{ + return null_aio_common(bs, cb, opaque); +} + +static void null_aio_cancel(BlockDriverAIOCB *blockacb) +{ + NullAIOCB *acb = container_of(blockacb, NullAIOCB, common); + qemu_bh_delete(acb->bh); + qemu_aio_release(acb); +} + +static BlockDriver bdrv_null = { + .format_name = "null", + .protocol_name = "null", + .instance_size = sizeof(BDRVNullState), + + .bdrv_file_open = null_file_open, + .bdrv_close = null_close, + .bdrv_getlength = null_getlength, + + .bdrv_aio_readv = null_aio_readv, + .bdrv_aio_writev = null_aio_writev, + .bdrv_aio_flush = null_aio_flush, +}; + +static BlockDriver bdrv_null_co = { + .format_name = "null-co", + .protocol_name = "null-co", + .instance_size = sizeof(BDRVNullState), + + .bdrv_file_open = null_file_open, + .bdrv_close = null_close, + .bdrv_getlength = null_getlength, + + .bdrv_read = null_co_read, + .bdrv_write = null_co_write, + .bdrv_co_flush_to_disk = null_co_flush, +}; + +static void bdrv_null_init(void) +{ + bdrv_register(&bdrv_null); + bdrv_register(&bdrv_null_co); +} + +block_init(bdrv_null_init); diff --git a/qapi/block-core.json b/qapi/block-core.json index fb74c56..92e294c 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1150,7 +1150,8 @@ 'data': [ 'archipelago', 'file', 'host_device', 'host_cdrom', 'host_floppy', 'http', 'https', 'ftp', 'ftps', 'tftp', 'vvfat', 'blkdebug', 'blkverify', 'bochs', 'cloop', 'cow', 'dmg', 'parallels', 'qcow', - 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum' ] } + 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum', + 'null', 'null-co' ] } ## # @BlockdevOptionsBase @@ -1203,6 +1204,19 @@ 'data': { 'filename': 'str' } } ## +# @BlockdevOptionsNull +# +# Driver specific block device options for the null backend. +# +# @size: #optional size of the device in bytes. +# +# Since: 2.2 +## +{ 'type': 'BlockdevOptionsNull', + 'base': 'BlockdevOptionsFile', + 'data': { '*size': 'int' } } + +## # @BlockdevOptionsVVFAT # # Driver specific block device options for the vvfat protocol. @@ -1484,7 +1498,9 @@ 'vhdx': 'BlockdevOptionsGenericFormat', 'vmdk': 'BlockdevOptionsGenericCOWFormat', 'vpc': 'BlockdevOptionsGenericFormat', - 'quorum': 'BlockdevOptionsQuorum' + 'quorum': 'BlockdevOptionsQuorum', + 'null': 'BlockdevOptionsNull', + 'null-co': 'BlockdevOptionsNull' } } ##
This is an analogue to Linux null_blk. It can be used for testing or benchmarking block device emulation and general block layer functionalities such as coroutines and throttling, where disk IO is not necessary or wanted. Use null:// for AIO version, and null-co:// for coroutine version. Signed-off-by: Fam Zheng <famz@redhat.com> --- V4: Add "#optional". (Eric) Add null_aio_common. (Benoit) Add null-co in json schema. (Eric, Benoit) --- block/Makefile.objs | 1 + block/null.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++++++ qapi/block-core.json | 20 +++++- 3 files changed, 195 insertions(+), 2 deletions(-) create mode 100644 block/null.c