* [Qemu-devel] [PATCH 1/3] gluster: Convert aio routines into coroutines
2013-12-21 9:21 [Qemu-devel] [PATCH v2 0/3] gluster: conversion to coroutines and supporting write_zeroes Bharata B Rao
@ 2013-12-21 9:21 ` Bharata B Rao
2013-12-21 9:21 ` [Qemu-devel] [PATCH 2/3] gluster: Implement .bdrv_co_write_zeroes for gluster Bharata B Rao
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Bharata B Rao @ 2013-12-21 9:21 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, pbonzini, jcody, stefanha, Bharata B Rao
Convert the read, write, flush and discard implementations from aio-based
ones to coroutine based ones.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
block/gluster.c | 221 +++++++++++++++++++-------------------------------------
1 file changed, 74 insertions(+), 147 deletions(-)
diff --git a/block/gluster.c b/block/gluster.c
index 877686a..7211a75 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -21,19 +21,15 @@
#include "qemu/uri.h"
typedef struct GlusterAIOCB {
- BlockDriverAIOCB common;
int64_t size;
int ret;
- bool *finished;
QEMUBH *bh;
+ Coroutine *coroutine;
} GlusterAIOCB;
typedef struct BDRVGlusterState {
struct glfs *glfs;
- int fds[2];
struct glfs_fd *fd;
- int event_reader_pos;
- GlusterAIOCB *event_acb;
} BDRVGlusterState;
#define GLUSTER_FD_READ 0
@@ -231,46 +227,13 @@ out:
return NULL;
}
-static void qemu_gluster_complete_aio(GlusterAIOCB *acb, BDRVGlusterState *s)
+static void qemu_gluster_complete_aio(void *opaque)
{
- int ret;
- bool *finished = acb->finished;
- BlockDriverCompletionFunc *cb = acb->common.cb;
- void *opaque = acb->common.opaque;
-
- if (!acb->ret || acb->ret == acb->size) {
- ret = 0; /* Success */
- } else if (acb->ret < 0) {
- ret = acb->ret; /* Read/Write failed */
- } else {
- ret = -EIO; /* Partial read/write - fail it */
- }
+ GlusterAIOCB *acb = (GlusterAIOCB *)opaque;
- qemu_aio_release(acb);
- cb(opaque, ret);
- if (finished) {
- *finished = true;
- }
-}
-
-static void qemu_gluster_aio_event_reader(void *opaque)
-{
- BDRVGlusterState *s = opaque;
- ssize_t ret;
-
- do {
- char *p = (char *)&s->event_acb;
-
- ret = read(s->fds[GLUSTER_FD_READ], p + s->event_reader_pos,
- sizeof(s->event_acb) - s->event_reader_pos);
- if (ret > 0) {
- s->event_reader_pos += ret;
- if (s->event_reader_pos == sizeof(s->event_acb)) {
- s->event_reader_pos = 0;
- qemu_gluster_complete_aio(s->event_acb, s);
- }
- }
- } while (ret < 0 && errno == EINTR);
+ qemu_bh_delete(acb->bh);
+ acb->bh = NULL;
+ qemu_coroutine_enter(acb->coroutine, NULL);
}
/* TODO Convert to fine grained options */
@@ -309,7 +272,6 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
filename = qemu_opt_get(opts, "filename");
-
s->glfs = qemu_gluster_init(gconf, filename);
if (!s->glfs) {
ret = -errno;
@@ -329,17 +291,7 @@ static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
s->fd = glfs_open(s->glfs, gconf->image, open_flags);
if (!s->fd) {
ret = -errno;
- goto out;
- }
-
- ret = qemu_pipe(s->fds);
- if (ret < 0) {
- ret = -errno;
- goto out;
}
- fcntl(s->fds[GLUSTER_FD_READ], F_SETFL, O_NONBLOCK);
- qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ],
- qemu_gluster_aio_event_reader, NULL, s);
out:
qemu_opts_del(opts);
@@ -398,58 +350,37 @@ out:
return ret;
}
-static void qemu_gluster_aio_cancel(BlockDriverAIOCB *blockacb)
-{
- GlusterAIOCB *acb = (GlusterAIOCB *)blockacb;
- bool finished = false;
-
- acb->finished = &finished;
- while (!finished) {
- qemu_aio_wait();
- }
-}
-
-static const AIOCBInfo gluster_aiocb_info = {
- .aiocb_size = sizeof(GlusterAIOCB),
- .cancel = qemu_gluster_aio_cancel,
-};
-
+/*
+ * AIO callback routine called from GlusterFS thread.
+ */
static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
{
GlusterAIOCB *acb = (GlusterAIOCB *)arg;
- BlockDriverState *bs = acb->common.bs;
- BDRVGlusterState *s = bs->opaque;
- int retval;
-
- acb->ret = ret;
- retval = qemu_write_full(s->fds[GLUSTER_FD_WRITE], &acb, sizeof(acb));
- if (retval != sizeof(acb)) {
- /*
- * Gluster AIO callback thread failed to notify the waiting
- * QEMU thread about IO completion.
- */
- error_report("Gluster AIO completion failed: %s", strerror(errno));
- abort();
+
+ if (!ret || ret == acb->size) {
+ acb->ret = 0; /* Success */
+ } else if (ret < 0) {
+ acb->ret = ret; /* Read/Write failed */
+ } else {
+ acb->ret = -EIO; /* Partial read/write - fail it */
}
+
+ acb->bh = qemu_bh_new(qemu_gluster_complete_aio, acb);
+ qemu_bh_schedule(acb->bh);
}
-static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque, int write)
+static coroutine_fn int qemu_gluster_co_rw(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int write)
{
int ret;
- GlusterAIOCB *acb;
+ GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
- size_t size;
- off_t offset;
+ size_t size = nb_sectors * BDRV_SECTOR_SIZE;
+ off_t offset = sector_num * BDRV_SECTOR_SIZE;
- offset = sector_num * BDRV_SECTOR_SIZE;
- size = nb_sectors * BDRV_SECTOR_SIZE;
-
- acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
acb->size = size;
acb->ret = 0;
- acb->finished = NULL;
+ acb->coroutine = qemu_coroutine_self();
if (write) {
ret = glfs_pwritev_async(s->fd, qiov->iov, qiov->niov, offset, 0,
@@ -460,13 +391,16 @@ static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs,
}
if (ret < 0) {
+ ret = -errno;
goto out;
}
- return &acb->common;
+
+ qemu_coroutine_yield();
+ ret = acb->ret;
out:
- qemu_aio_release(acb);
- return NULL;
+ g_slice_free(GlusterAIOCB, acb);
+ return ret;
}
static int qemu_gluster_truncate(BlockDriverState *bs, int64_t offset)
@@ -482,71 +416,68 @@ static int qemu_gluster_truncate(BlockDriverState *bs, int64_t offset)
return 0;
}
-static BlockDriverAIOCB *qemu_gluster_aio_readv(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque)
+static coroutine_fn int qemu_gluster_co_readv(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
- return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 0);
}
-static BlockDriverAIOCB *qemu_gluster_aio_writev(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque)
+static coroutine_fn int qemu_gluster_co_writev(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
- return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
+ return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 1);
}
-static BlockDriverAIOCB *qemu_gluster_aio_flush(BlockDriverState *bs,
- BlockDriverCompletionFunc *cb, void *opaque)
+static coroutine_fn int qemu_gluster_co_flush_to_disk(BlockDriverState *bs)
{
int ret;
- GlusterAIOCB *acb;
+ GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
- acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
acb->size = 0;
acb->ret = 0;
- acb->finished = NULL;
+ acb->coroutine = qemu_coroutine_self();
ret = glfs_fsync_async(s->fd, &gluster_finish_aiocb, acb);
if (ret < 0) {
+ ret = -errno;
goto out;
}
- return &acb->common;
+
+ qemu_coroutine_yield();
+ ret = acb->ret;
out:
- qemu_aio_release(acb);
- return NULL;
+ g_slice_free(GlusterAIOCB, acb);
+ return ret;
}
#ifdef CONFIG_GLUSTERFS_DISCARD
-static BlockDriverAIOCB *qemu_gluster_aio_discard(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, BlockDriverCompletionFunc *cb,
- void *opaque)
+static coroutine_fn int qemu_gluster_co_discard(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors)
{
int ret;
- GlusterAIOCB *acb;
+ GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
- size_t size;
- off_t offset;
-
- offset = sector_num * BDRV_SECTOR_SIZE;
- size = nb_sectors * BDRV_SECTOR_SIZE;
+ size_t size = nb_sectors * BDRV_SECTOR_SIZE;
+ off_t offset = sector_num * BDRV_SECTOR_SIZE;
- acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
acb->size = 0;
acb->ret = 0;
- acb->finished = NULL;
+ acb->coroutine = qemu_coroutine_self();
ret = glfs_discard_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
if (ret < 0) {
+ ret = -errno;
goto out;
}
- return &acb->common;
+
+ qemu_coroutine_yield();
+ ret = acb->ret;
out:
- qemu_aio_release(acb);
- return NULL;
+ g_slice_free(GlusterAIOCB, acb);
+ return ret;
}
#endif
@@ -581,10 +512,6 @@ static void qemu_gluster_close(BlockDriverState *bs)
{
BDRVGlusterState *s = bs->opaque;
- close(s->fds[GLUSTER_FD_READ]);
- close(s->fds[GLUSTER_FD_WRITE]);
- qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL);
-
if (s->fd) {
glfs_close(s->fd);
s->fd = NULL;
@@ -618,12 +545,12 @@ static BlockDriver bdrv_gluster = {
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
- .bdrv_aio_readv = qemu_gluster_aio_readv,
- .bdrv_aio_writev = qemu_gluster_aio_writev,
- .bdrv_aio_flush = qemu_gluster_aio_flush,
+ .bdrv_co_readv = qemu_gluster_co_readv,
+ .bdrv_co_writev = qemu_gluster_co_writev,
+ .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk,
.bdrv_has_zero_init = qemu_gluster_has_zero_init,
#ifdef CONFIG_GLUSTERFS_DISCARD
- .bdrv_aio_discard = qemu_gluster_aio_discard,
+ .bdrv_co_discard = qemu_gluster_co_discard,
#endif
.create_options = qemu_gluster_create_options,
};
@@ -639,12 +566,12 @@ static BlockDriver bdrv_gluster_tcp = {
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
- .bdrv_aio_readv = qemu_gluster_aio_readv,
- .bdrv_aio_writev = qemu_gluster_aio_writev,
- .bdrv_aio_flush = qemu_gluster_aio_flush,
+ .bdrv_co_readv = qemu_gluster_co_readv,
+ .bdrv_co_writev = qemu_gluster_co_writev,
+ .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk,
.bdrv_has_zero_init = qemu_gluster_has_zero_init,
#ifdef CONFIG_GLUSTERFS_DISCARD
- .bdrv_aio_discard = qemu_gluster_aio_discard,
+ .bdrv_co_discard = qemu_gluster_co_discard,
#endif
.create_options = qemu_gluster_create_options,
};
@@ -660,12 +587,12 @@ static BlockDriver bdrv_gluster_unix = {
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
- .bdrv_aio_readv = qemu_gluster_aio_readv,
- .bdrv_aio_writev = qemu_gluster_aio_writev,
- .bdrv_aio_flush = qemu_gluster_aio_flush,
+ .bdrv_co_readv = qemu_gluster_co_readv,
+ .bdrv_co_writev = qemu_gluster_co_writev,
+ .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk,
.bdrv_has_zero_init = qemu_gluster_has_zero_init,
#ifdef CONFIG_GLUSTERFS_DISCARD
- .bdrv_aio_discard = qemu_gluster_aio_discard,
+ .bdrv_co_discard = qemu_gluster_co_discard,
#endif
.create_options = qemu_gluster_create_options,
};
@@ -681,12 +608,12 @@ static BlockDriver bdrv_gluster_rdma = {
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
- .bdrv_aio_readv = qemu_gluster_aio_readv,
- .bdrv_aio_writev = qemu_gluster_aio_writev,
- .bdrv_aio_flush = qemu_gluster_aio_flush,
+ .bdrv_co_readv = qemu_gluster_co_readv,
+ .bdrv_co_writev = qemu_gluster_co_writev,
+ .bdrv_co_flush_to_disk = qemu_gluster_co_flush_to_disk,
.bdrv_has_zero_init = qemu_gluster_has_zero_init,
#ifdef CONFIG_GLUSTERFS_DISCARD
- .bdrv_aio_discard = qemu_gluster_aio_discard,
+ .bdrv_co_discard = qemu_gluster_co_discard,
#endif
.create_options = qemu_gluster_create_options,
};
--
1.7.11.7
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Qemu-devel] [PATCH 2/3] gluster: Implement .bdrv_co_write_zeroes for gluster
2013-12-21 9:21 [Qemu-devel] [PATCH v2 0/3] gluster: conversion to coroutines and supporting write_zeroes Bharata B Rao
2013-12-21 9:21 ` [Qemu-devel] [PATCH 1/3] gluster: Convert aio routines into coroutines Bharata B Rao
@ 2013-12-21 9:21 ` Bharata B Rao
2013-12-21 9:21 ` [Qemu-devel] [PATCH 3/3] gluster: Add support for creating zero-filled image Bharata B Rao
2014-01-06 2:11 ` [Qemu-devel] [PATCH v2 0/3] gluster: conversion to coroutines and supporting write_zeroes Stefan Hajnoczi
3 siblings, 0 replies; 5+ messages in thread
From: Bharata B Rao @ 2013-12-21 9:21 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, pbonzini, jcody, stefanha, Bharata B Rao
Support .bdrv_co_write_zeroes() from gluster driver by using GlusterFS API
glfs_zerofill() that off-loads the writing of zeroes to GlusterFS server.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
block/gluster.c | 79 +++++++++++++++++++++++++++++++++++++++++++--------------
configure | 8 ++++++
2 files changed, 68 insertions(+), 19 deletions(-)
diff --git a/block/gluster.c b/block/gluster.c
index 7211a75..3c796be 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -236,6 +236,25 @@ static void qemu_gluster_complete_aio(void *opaque)
qemu_coroutine_enter(acb->coroutine, NULL);
}
+/*
+ * AIO callback routine called from GlusterFS thread.
+ */
+static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
+{
+ GlusterAIOCB *acb = (GlusterAIOCB *)arg;
+
+ if (!ret || ret == acb->size) {
+ acb->ret = 0; /* Success */
+ } else if (ret < 0) {
+ acb->ret = ret; /* Read/Write failed */
+ } else {
+ acb->ret = -EIO; /* Partial read/write - fail it */
+ }
+
+ acb->bh = qemu_bh_new(qemu_gluster_complete_aio, acb);
+ qemu_bh_schedule(acb->bh);
+}
+
/* TODO Convert to fine grained options */
static QemuOptsList runtime_opts = {
.name = "gluster",
@@ -308,6 +327,35 @@ out:
return ret;
}
+#ifdef CONFIG_GLUSTERFS_ZEROFILL
+static coroutine_fn int qemu_gluster_co_write_zeroes(BlockDriverState *bs,
+ int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
+{
+ int ret;
+ GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
+ BDRVGlusterState *s = bs->opaque;
+ off_t size = nb_sectors * BDRV_SECTOR_SIZE;
+ off_t offset = sector_num * BDRV_SECTOR_SIZE;
+
+ acb->size = size;
+ acb->ret = 0;
+ acb->coroutine = qemu_coroutine_self();
+
+ ret = glfs_zerofill_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
+ if (ret < 0) {
+ ret = -errno;
+ goto out;
+ }
+
+ qemu_coroutine_yield();
+ ret = acb->ret;
+
+out:
+ g_slice_free(GlusterAIOCB, acb);
+ return ret;
+}
+#endif
+
static int qemu_gluster_create(const char *filename,
QEMUOptionParameter *options, Error **errp)
{
@@ -350,25 +398,6 @@ out:
return ret;
}
-/*
- * AIO callback routine called from GlusterFS thread.
- */
-static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
-{
- GlusterAIOCB *acb = (GlusterAIOCB *)arg;
-
- if (!ret || ret == acb->size) {
- acb->ret = 0; /* Success */
- } else if (ret < 0) {
- acb->ret = ret; /* Read/Write failed */
- } else {
- acb->ret = -EIO; /* Partial read/write - fail it */
- }
-
- acb->bh = qemu_bh_new(qemu_gluster_complete_aio, acb);
- qemu_bh_schedule(acb->bh);
-}
-
static coroutine_fn int qemu_gluster_co_rw(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int write)
{
@@ -552,6 +581,9 @@ static BlockDriver bdrv_gluster = {
#ifdef CONFIG_GLUSTERFS_DISCARD
.bdrv_co_discard = qemu_gluster_co_discard,
#endif
+#ifdef CONFIG_GLUSTERFS_ZEROFILL
+ .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
+#endif
.create_options = qemu_gluster_create_options,
};
@@ -573,6 +605,9 @@ static BlockDriver bdrv_gluster_tcp = {
#ifdef CONFIG_GLUSTERFS_DISCARD
.bdrv_co_discard = qemu_gluster_co_discard,
#endif
+#ifdef CONFIG_GLUSTERFS_ZEROFILL
+ .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
+#endif
.create_options = qemu_gluster_create_options,
};
@@ -594,6 +629,9 @@ static BlockDriver bdrv_gluster_unix = {
#ifdef CONFIG_GLUSTERFS_DISCARD
.bdrv_co_discard = qemu_gluster_co_discard,
#endif
+#ifdef CONFIG_GLUSTERFS_ZEROFILL
+ .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
+#endif
.create_options = qemu_gluster_create_options,
};
@@ -615,6 +653,9 @@ static BlockDriver bdrv_gluster_rdma = {
#ifdef CONFIG_GLUSTERFS_DISCARD
.bdrv_co_discard = qemu_gluster_co_discard,
#endif
+#ifdef CONFIG_GLUSTERFS_ZEROFILL
+ .bdrv_co_write_zeroes = qemu_gluster_co_write_zeroes,
+#endif
.create_options = qemu_gluster_create_options,
};
diff --git a/configure b/configure
index 07b6be3..64cac73 100755
--- a/configure
+++ b/configure
@@ -256,6 +256,7 @@ coroutine_pool=""
seccomp=""
glusterfs=""
glusterfs_discard="no"
+glusterfs_zerofill="no"
virtio_blk_data_plane=""
gtk=""
gtkabi="2.0"
@@ -2701,6 +2702,9 @@ if test "$glusterfs" != "no" ; then
if $pkg_config --atleast-version=5 glusterfs-api; then
glusterfs_discard="yes"
fi
+ if $pkg_config --atleast-version=6 glusterfs-api; then
+ glusterfs_zerofill="yes"
+ fi
else
if test "$glusterfs" = "yes" ; then
feature_not_found "GlusterFS backend support"
@@ -4207,6 +4211,10 @@ if test "$glusterfs_discard" = "yes" ; then
echo "CONFIG_GLUSTERFS_DISCARD=y" >> $config_host_mak
fi
+if test "$glusterfs_zerofill" = "yes" ; then
+ echo "CONFIG_GLUSTERFS_ZEROFILL=y" >> $config_host_mak
+fi
+
if test "$libssh2" = "yes" ; then
echo "CONFIG_LIBSSH2=y" >> $config_host_mak
fi
--
1.7.11.7
^ permalink raw reply related [flat|nested] 5+ messages in thread* [Qemu-devel] [PATCH 3/3] gluster: Add support for creating zero-filled image
2013-12-21 9:21 [Qemu-devel] [PATCH v2 0/3] gluster: conversion to coroutines and supporting write_zeroes Bharata B Rao
2013-12-21 9:21 ` [Qemu-devel] [PATCH 1/3] gluster: Convert aio routines into coroutines Bharata B Rao
2013-12-21 9:21 ` [Qemu-devel] [PATCH 2/3] gluster: Implement .bdrv_co_write_zeroes for gluster Bharata B Rao
@ 2013-12-21 9:21 ` Bharata B Rao
2014-01-06 2:11 ` [Qemu-devel] [PATCH v2 0/3] gluster: conversion to coroutines and supporting write_zeroes Stefan Hajnoczi
3 siblings, 0 replies; 5+ messages in thread
From: Bharata B Rao @ 2013-12-21 9:21 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, pbonzini, jcody, stefanha, Bharata B Rao
GlusterFS supports creation of zero-filled file on GlusterFS volume
by means of an API called glfs_zerofill(). Use this API from QEMU to
create an image that is filled with zeroes by using the preallocation
option of qemu-img.
qemu-img create gluster://server/volume/image -o preallocation=full 10G
The allowed values for preallocation are 'full' and 'off'. By default
preallocation is off and image is not zero-filled.
glfs_zerofill() offloads the writing of zeroes to the server and if
the storage supports SCSI WRITESAME, GlusterFS server can issue
BLKZEROOUT ioctl to achieve the zeroing.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
block/gluster.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 49 insertions(+), 1 deletion(-)
diff --git a/block/gluster.c b/block/gluster.c
index 3c796be..98f6859 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -354,6 +354,29 @@ out:
g_slice_free(GlusterAIOCB, acb);
return ret;
}
+
+static inline bool gluster_supports_zerofill(void)
+{
+ return 1;
+}
+
+static inline int qemu_gluster_zerofill(struct glfs_fd *fd, int64_t offset,
+ int64_t size)
+{
+ return glfs_zerofill(fd, offset, size);
+}
+
+#else
+static inline bool gluster_supports_zerofill(void)
+{
+ return 0;
+}
+
+static inline int qemu_gluster_zerofill(struct glfs_fd *fd, int64_t offset,
+ int64_t size)
+{
+ return 0;
+}
#endif
static int qemu_gluster_create(const char *filename,
@@ -362,6 +385,7 @@ static int qemu_gluster_create(const char *filename,
struct glfs *glfs;
struct glfs_fd *fd;
int ret = 0;
+ int prealloc = 0;
int64_t total_size = 0;
GlusterConf *gconf = g_malloc0(sizeof(GlusterConf));
@@ -374,6 +398,19 @@ static int qemu_gluster_create(const char *filename,
while (options && options->name) {
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
total_size = options->value.n / BDRV_SECTOR_SIZE;
+ } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
+ if (!options->value.s || !strcmp(options->value.s, "off")) {
+ prealloc = 0;
+ } else if (!strcmp(options->value.s, "full") &&
+ gluster_supports_zerofill()) {
+ prealloc = 1;
+ } else {
+ error_setg(errp, "Invalid preallocation mode: '%s'"
+ " or GlusterFS doesn't support zerofill API",
+ options->value.s);
+ ret = -EINVAL;
+ goto out;
+ }
}
options++;
}
@@ -383,9 +420,15 @@ static int qemu_gluster_create(const char *filename,
if (!fd) {
ret = -errno;
} else {
- if (glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) {
+ if (!glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE)) {
+ if (prealloc && qemu_gluster_zerofill(fd, 0,
+ total_size * BDRV_SECTOR_SIZE)) {
+ ret = -errno;
+ }
+ } else {
ret = -errno;
}
+
if (glfs_close(fd) != 0) {
ret = -errno;
}
@@ -560,6 +603,11 @@ static QEMUOptionParameter qemu_gluster_create_options[] = {
.type = OPT_SIZE,
.help = "Virtual disk size"
},
+ {
+ .name = BLOCK_OPT_PREALLOC,
+ .type = OPT_STRING,
+ .help = "Preallocation mode (allowed values: off, full)"
+ },
{ NULL }
};
--
1.7.11.7
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