* [Qemu-devel] [PATCH v2] block/rbd: add preallocation support
@ 2019-05-06 12:23 Stefano Garzarella
2019-06-25 16:06 ` Max Reitz
0 siblings, 1 reply; 3+ messages in thread
From: Stefano Garzarella @ 2019-05-06 12:23 UTC (permalink / raw)
To: qemu-devel
Cc: Kevin Wolf, Josh Durgin, qemu-block, Markus Armbruster,
Max Reitz, Jason Dillaman
This patch adds the support of preallocation (off/full) for the RBD
block driver.
If available, we use rbd_writesame() to quickly fill the image when
full preallocation is required.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v2:
- Use 4 KiB buffer for rbd_writesame() [Jason]
- Use "rbd_concurrent_management_ops" and "stripe_unit" to limit
concurrent ops to the backing cluster [Jason]
---
block/rbd.c | 188 +++++++++++++++++++++++++++++++++++++++----
qapi/block-core.json | 4 +-
2 files changed, 175 insertions(+), 17 deletions(-)
diff --git a/block/rbd.c b/block/rbd.c
index 0c549c9935..bc54395e1c 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -13,6 +13,7 @@
#include "qemu/osdep.h"
+#include "qemu/units.h"
#include <rbd/librbd.h>
#include "qapi/error.h"
#include "qemu/error-report.h"
@@ -63,6 +64,7 @@
#define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)
#define RBD_MAX_SNAPS 100
+#define RBD_DEFAULT_CONCURRENT_OPS 10
/* The LIBRBD_SUPPORTS_IOVEC is defined in librbd.h */
#ifdef LIBRBD_SUPPORTS_IOVEC
@@ -331,6 +333,147 @@ static void qemu_rbd_memset(RADOSCB *rcb, int64_t offs)
}
}
+static int qemu_rbd_get_max_concurrent_ops(rados_t cluster)
+{
+ char buf[16];
+ int ret, max_concurrent_ops;
+
+ ret = rados_conf_get(cluster, "rbd_concurrent_management_ops", buf,
+ sizeof(buf));
+ if (ret < 0) {
+ return RBD_DEFAULT_CONCURRENT_OPS;
+ }
+
+ ret = qemu_strtoi(buf, NULL, 10, &max_concurrent_ops);
+ if (ret < 0) {
+ return RBD_DEFAULT_CONCURRENT_OPS;
+ }
+
+ return max_concurrent_ops;
+}
+
+static int qemu_rbd_do_truncate(rados_t cluster, rbd_image_t image,
+ int64_t offset, PreallocMode prealloc,
+ Error **errp)
+{
+ uint64_t current_length;
+ char *buf = NULL;
+ int ret;
+
+ ret = rbd_get_size(image, ¤t_length);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to get file length");
+ goto out;
+ }
+
+ if (current_length > offset && prealloc != PREALLOC_MODE_OFF) {
+ error_setg(errp, "Cannot use preallocation for shrinking files");
+ ret = -ENOTSUP;
+ goto out;
+ }
+
+ switch (prealloc) {
+ case PREALLOC_MODE_FULL: {
+ uint64_t current_offset = current_length;
+ int buf_size = 4 * KiB;
+ ssize_t bytes;
+
+#ifdef LIBRBD_SUPPORTS_WRITESAME
+ uint64_t stripe_unit, writesame_max_size;
+ int max_concurrent_ops;
+
+ max_concurrent_ops = qemu_rbd_get_max_concurrent_ops(cluster);
+ ret = rbd_get_stripe_unit(image, &stripe_unit);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to get stripe unit");
+ goto out;
+ }
+
+ /*
+ * We limit the rbd_writesame() size to avoid to spawn more then
+ * 'rbd_concurrent_management_ops' concurrent operations.
+ */
+ writesame_max_size = MIN(stripe_unit * max_concurrent_ops, INT_MAX);
+#endif /* LIBRBD_SUPPORTS_WRITESAME */
+
+ buf = g_malloc(buf_size);
+ /*
+ * Some versions of rbd_writesame() discards writes of buffers with
+ * all zeroes. In order to avoid this behaviour, we set the first byte
+ * to one.
+ */
+ buf[0] = 1;
+
+ ret = rbd_resize(image, offset);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to resize file");
+ goto out;
+ }
+
+#ifdef LIBRBD_SUPPORTS_WRITESAME
+ while (offset - current_offset > buf_size) {
+ bytes = MIN(offset - current_offset, writesame_max_size);
+ /*
+ * rbd_writesame() supports only request where the size of the
+ * operation is multiple of buffer size.
+ */
+ bytes -= bytes % buf_size;
+
+ bytes = rbd_writesame(image, current_offset, bytes, buf, buf_size,
+ 0);
+ if (bytes < 0) {
+ ret = bytes;
+ error_setg_errno(errp, -ret,
+ "Failed to write for preallocation");
+ goto out;
+ }
+
+ current_offset += bytes;
+ }
+#endif /* LIBRBD_SUPPORTS_WRITESAME */
+
+ while (current_offset < offset) {
+ bytes = rbd_write(image, current_offset,
+ MIN(offset - current_offset, buf_size), buf);
+ if (bytes < 0) {
+ ret = bytes;
+ error_setg_errno(errp, -ret,
+ "Failed to write for preallocation");
+ goto out;
+ }
+
+ current_offset += bytes;
+ }
+
+ ret = rbd_flush(image);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to flush the file");
+ goto out;
+ }
+
+ break;
+ }
+ case PREALLOC_MODE_OFF:
+ ret = rbd_resize(image, offset);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to resize file");
+ goto out;
+ }
+ break;
+ default:
+ error_setg(errp, "Unsupported preallocation mode: %s",
+ PreallocMode_str(prealloc));
+ ret = -ENOTSUP;
+ goto out;
+ }
+
+ ret = 0;
+
+out:
+ g_free(buf);
+ return ret;
+}
+
static QemuOptsList runtime_opts = {
.name = "rbd",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
@@ -376,6 +519,7 @@ static int qemu_rbd_do_create(BlockdevCreateOptions *options,
BlockdevCreateOptionsRbd *opts = &options->u.rbd;
rados_t cluster;
rados_ioctx_t io_ctx;
+ rbd_image_t image;
int obj_order = 0;
int ret;
@@ -404,13 +548,22 @@ static int qemu_rbd_do_create(BlockdevCreateOptions *options,
return ret;
}
- ret = rbd_create(io_ctx, opts->location->image, opts->size, &obj_order);
+ ret = rbd_create(io_ctx, opts->location->image, 0, &obj_order);
if (ret < 0) {
error_setg_errno(errp, -ret, "error rbd create");
goto out;
}
- ret = 0;
+ ret = rbd_open(io_ctx, opts->location->image, &image, NULL);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "error rbd open");
+ goto out;
+ }
+
+ ret = qemu_rbd_do_truncate(cluster, image, opts->size, opts->preallocation,
+ errp);
+
+ rbd_close(image);
out:
rados_ioctx_destroy(io_ctx);
rados_shutdown(cluster);
@@ -431,6 +584,7 @@ static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
BlockdevOptionsRbd *loc;
Error *local_err = NULL;
const char *keypairs, *password_secret;
+ char *prealloc;
QDict *options = NULL;
int ret = 0;
@@ -449,6 +603,16 @@ static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
BLOCK_OPT_CLUSTER_SIZE, 0);
rbd_opts->has_cluster_size = (rbd_opts->cluster_size != 0);
+ prealloc = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+ rbd_opts->preallocation = qapi_enum_parse(&PreallocMode_lookup, prealloc,
+ PREALLOC_MODE_OFF, &local_err);
+ g_free(prealloc);
+ if (local_err) {
+ ret = -EINVAL;
+ error_propagate(errp, local_err);
+ goto exit;
+ }
+
options = qdict_new();
qemu_rbd_parse_filename(filename, options, &local_err);
if (local_err) {
@@ -1052,21 +1216,8 @@ static int coroutine_fn qemu_rbd_co_truncate(BlockDriverState *bs,
Error **errp)
{
BDRVRBDState *s = bs->opaque;
- int r;
- if (prealloc != PREALLOC_MODE_OFF) {
- error_setg(errp, "Unsupported preallocation mode '%s'",
- PreallocMode_str(prealloc));
- return -ENOTSUP;
- }
-
- r = rbd_resize(s->image, offset);
- if (r < 0) {
- error_setg_errno(errp, -r, "Failed to resize file");
- return r;
- }
-
- return 0;
+ return qemu_rbd_do_truncate(s->cluster, s->image, offset, prealloc, errp);
}
static int qemu_rbd_snap_create(BlockDriverState *bs,
@@ -1219,6 +1370,11 @@ static QemuOptsList qemu_rbd_create_opts = {
.type = QEMU_OPT_SIZE,
.help = "RBD object size"
},
+ {
+ .name = BLOCK_OPT_PREALLOC,
+ .type = QEMU_OPT_STRING,
+ .help = "Preallocation mode (allowed values: off, full)"
+ },
{
.name = "password-secret",
.type = QEMU_OPT_STRING,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 7ccbfff9d0..db25a4065b 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4277,13 +4277,15 @@
# point to a snapshot.
# @size Size of the virtual disk in bytes
# @cluster-size RBD object size
+# @preallocation Preallocation mode (allowed values: off, full)
#
# Since: 2.12
##
{ 'struct': 'BlockdevCreateOptionsRbd',
'data': { 'location': 'BlockdevOptionsRbd',
'size': 'size',
- '*cluster-size' : 'size' } }
+ '*cluster-size' : 'size',
+ '*preallocation': 'PreallocMode' } }
##
# @BlockdevVmdkSubformat:
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] block/rbd: add preallocation support
2019-05-06 12:23 [Qemu-devel] [PATCH v2] block/rbd: add preallocation support Stefano Garzarella
@ 2019-06-25 16:06 ` Max Reitz
2019-06-26 7:46 ` Stefano Garzarella
0 siblings, 1 reply; 3+ messages in thread
From: Max Reitz @ 2019-06-25 16:06 UTC (permalink / raw)
To: Stefano Garzarella, qemu-devel
Cc: Kevin Wolf, Josh Durgin, qemu-block, Markus Armbruster, Jason Dillaman
[-- Attachment #1.1: Type: text/plain, Size: 4114 bytes --]
On 06.05.19 14:23, Stefano Garzarella wrote:
> This patch adds the support of preallocation (off/full) for the RBD
> block driver.
> If available, we use rbd_writesame() to quickly fill the image when
> full preallocation is required.
>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v2:
> - Use 4 KiB buffer for rbd_writesame() [Jason]
> - Use "rbd_concurrent_management_ops" and "stripe_unit" to limit
> concurrent ops to the backing cluster [Jason]
> ---
> block/rbd.c | 188 +++++++++++++++++++++++++++++++++++++++----
> qapi/block-core.json | 4 +-
> 2 files changed, 175 insertions(+), 17 deletions(-)
This patch conflicts a bit with the rbd file growth patch, so that would
need to be resolved in a v3.
But still, that doesn’t prevent me from reviewing it as it is:
> diff --git a/block/rbd.c b/block/rbd.c
> index 0c549c9935..bc54395e1c 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
[...]
> @@ -331,6 +333,147 @@ static void qemu_rbd_memset(RADOSCB *rcb, int64_t offs)
[...]
> +static int qemu_rbd_do_truncate(rados_t cluster, rbd_image_t image,
> + int64_t offset, PreallocMode prealloc,
> + Error **errp)
> +{
[...]
> +#ifdef LIBRBD_SUPPORTS_WRITESAME
> + uint64_t stripe_unit, writesame_max_size;
> + int max_concurrent_ops;
> +
> + max_concurrent_ops = qemu_rbd_get_max_concurrent_ops(cluster);
> + ret = rbd_get_stripe_unit(image, &stripe_unit);
> + if (ret < 0) {
> + error_setg_errno(errp, -ret, "Failed to get stripe unit");
> + goto out;
> + }
> +
> + /*
> + * We limit the rbd_writesame() size to avoid to spawn more then
s/then/than/
> + * 'rbd_concurrent_management_ops' concurrent operations.
> + */
> + writesame_max_size = MIN(stripe_unit * max_concurrent_ops, INT_MAX);
> +#endif /* LIBRBD_SUPPORTS_WRITESAME */
> +
> + buf = g_malloc(buf_size);
> + /*
> + * Some versions of rbd_writesame() discards writes of buffers with
> + * all zeroes. In order to avoid this behaviour, we set the first byte
> + * to one.
> + */
> + buf[0] = 1;
But I guess you’ll need to rewrite it as zero later, or the
“bdrv_rbd.bdrv_has_zero_init = bdrv_has_zero_init_1” is no longer quite
true.
[...]
> @@ -449,6 +603,16 @@ static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
> BLOCK_OPT_CLUSTER_SIZE, 0);
> rbd_opts->has_cluster_size = (rbd_opts->cluster_size != 0);
>
> + prealloc = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
> + rbd_opts->preallocation = qapi_enum_parse(&PreallocMode_lookup, prealloc,
> + PREALLOC_MODE_OFF, &local_err);
You also need to set rbd_opts->has_preallocation to true.
> + g_free(prealloc);
> + if (local_err) {
> + ret = -EINVAL;
> + error_propagate(errp, local_err);
> + goto exit;
> + }
> +
> options = qdict_new();
> qemu_rbd_parse_filename(filename, options, &local_err);
> if (local_err) {
[...]
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 7ccbfff9d0..db25a4065b 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -4277,13 +4277,15 @@
> # point to a snapshot.
> # @size Size of the virtual disk in bytes
> # @cluster-size RBD object size
> +# @preallocation Preallocation mode (allowed values: off, full)
There should be a "(Since: 4.1)" note here.
Max
> #
> # Since: 2.12
> ##
> { 'struct': 'BlockdevCreateOptionsRbd',
> 'data': { 'location': 'BlockdevOptionsRbd',
> 'size': 'size',
> - '*cluster-size' : 'size' } }
> + '*cluster-size' : 'size',
> + '*preallocation': 'PreallocMode' } }
>
> ##
> # @BlockdevVmdkSubformat:
>
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v2] block/rbd: add preallocation support
2019-06-25 16:06 ` Max Reitz
@ 2019-06-26 7:46 ` Stefano Garzarella
0 siblings, 0 replies; 3+ messages in thread
From: Stefano Garzarella @ 2019-06-26 7:46 UTC (permalink / raw)
To: Max Reitz
Cc: Kevin Wolf, Josh Durgin, qemu-block, qemu-devel,
Markus Armbruster, Jason Dillaman
On Tue, Jun 25, 2019 at 06:06:02PM +0200, Max Reitz wrote:
> On 06.05.19 14:23, Stefano Garzarella wrote:
> > This patch adds the support of preallocation (off/full) for the RBD
> > block driver.
> > If available, we use rbd_writesame() to quickly fill the image when
> > full preallocation is required.
> >
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > ---
> > v2:
> > - Use 4 KiB buffer for rbd_writesame() [Jason]
> > - Use "rbd_concurrent_management_ops" and "stripe_unit" to limit
> > concurrent ops to the backing cluster [Jason]
> > ---
> > block/rbd.c | 188 +++++++++++++++++++++++++++++++++++++++----
> > qapi/block-core.json | 4 +-
> > 2 files changed, 175 insertions(+), 17 deletions(-)
>
> This patch conflicts a bit with the rbd file growth patch, so that would
> need to be resolved in a v3.
Sure, I'll rebase this patch in a v3!
>
> But still, that doesn’t prevent me from reviewing it as it is:
>
> > diff --git a/block/rbd.c b/block/rbd.c
> > index 0c549c9935..bc54395e1c 100644
> > --- a/block/rbd.c
> > +++ b/block/rbd.c
>
> [...]
>
> > @@ -331,6 +333,147 @@ static void qemu_rbd_memset(RADOSCB *rcb, int64_t offs)
>
> [...]
>
> > +static int qemu_rbd_do_truncate(rados_t cluster, rbd_image_t image,
> > + int64_t offset, PreallocMode prealloc,
> > + Error **errp)
> > +{
>
> [...]
>
> > +#ifdef LIBRBD_SUPPORTS_WRITESAME
> > + uint64_t stripe_unit, writesame_max_size;
> > + int max_concurrent_ops;
> > +
> > + max_concurrent_ops = qemu_rbd_get_max_concurrent_ops(cluster);
> > + ret = rbd_get_stripe_unit(image, &stripe_unit);
> > + if (ret < 0) {
> > + error_setg_errno(errp, -ret, "Failed to get stripe unit");
> > + goto out;
> > + }
> > +
> > + /*
> > + * We limit the rbd_writesame() size to avoid to spawn more then
>
> s/then/than/
Ooo, I'll fix it!
>
> > + * 'rbd_concurrent_management_ops' concurrent operations.
> > + */
> > + writesame_max_size = MIN(stripe_unit * max_concurrent_ops, INT_MAX);
> > +#endif /* LIBRBD_SUPPORTS_WRITESAME */
> > +
> > + buf = g_malloc(buf_size);
> > + /*
> > + * Some versions of rbd_writesame() discards writes of buffers with
> > + * all zeroes. In order to avoid this behaviour, we set the first byte
> > + * to one.
> > + */
> > + buf[0] = 1;
>
> But I guess you’ll need to rewrite it as zero later, or the
> “bdrv_rbd.bdrv_has_zero_init = bdrv_has_zero_init_1” is no longer quite
> true.
Yes, and I should use g_malloc0. I'll check if the next rewrites is too
slow, in this case I'll use rbd_writesame() only for ceph version where
zeroed buffer is supported.
>
> [...]
>
> > @@ -449,6 +603,16 @@ static int coroutine_fn qemu_rbd_co_create_opts(const char *filename,
> > BLOCK_OPT_CLUSTER_SIZE, 0);
> > rbd_opts->has_cluster_size = (rbd_opts->cluster_size != 0);
> >
> > + prealloc = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
> > + rbd_opts->preallocation = qapi_enum_parse(&PreallocMode_lookup, prealloc,
> > + PREALLOC_MODE_OFF, &local_err);
>
> You also need to set rbd_opts->has_preallocation to true.
I'll fix.
>
> > + g_free(prealloc);
> > + if (local_err) {
> > + ret = -EINVAL;
> > + error_propagate(errp, local_err);
> > + goto exit;
> > + }
> > +
> > options = qdict_new();
> > qemu_rbd_parse_filename(filename, options, &local_err);
> > if (local_err) {
>
> [...]
>
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 7ccbfff9d0..db25a4065b 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -4277,13 +4277,15 @@
> > # point to a snapshot.
> > # @size Size of the virtual disk in bytes
> > # @cluster-size RBD object size
> > +# @preallocation Preallocation mode (allowed values: off, full)
>
> There should be a "(Since: 4.1)" note here.
I'll add the note!
Thanks for the review,
Stefano
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-06-26 7:50 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-06 12:23 [Qemu-devel] [PATCH v2] block/rbd: add preallocation support Stefano Garzarella
2019-06-25 16:06 ` Max Reitz
2019-06-26 7:46 ` Stefano Garzarella
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).