qemu/block/gluster.c
Bharata B Rao cf7f616b9d gluster: Add support for creating zero-filled image
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>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-22 12:07:16 +01:00

719 lines
20 KiB
C

/*
* GlusterFS backend for QEMU
*
* Copyright (C) 2012 Bharata B Rao <bharata@linux.vnet.ibm.com>
*
* Pipe handling mechanism in AIO implementation is derived from
* block/rbd.c. Hence,
*
* Copyright (C) 2010-2011 Christian Brunner <chb@muc.de>,
* Josh Durgin <josh.durgin@dreamhost.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include <glusterfs/api/glfs.h>
#include "block/block_int.h"
#include "qemu/sockets.h"
#include "qemu/uri.h"
typedef struct GlusterAIOCB {
int64_t size;
int ret;
QEMUBH *bh;
Coroutine *coroutine;
} GlusterAIOCB;
typedef struct BDRVGlusterState {
struct glfs *glfs;
struct glfs_fd *fd;
} BDRVGlusterState;
#define GLUSTER_FD_READ 0
#define GLUSTER_FD_WRITE 1
typedef struct GlusterConf {
char *server;
int port;
char *volname;
char *image;
char *transport;
} GlusterConf;
static void qemu_gluster_gconf_free(GlusterConf *gconf)
{
g_free(gconf->server);
g_free(gconf->volname);
g_free(gconf->image);
g_free(gconf->transport);
g_free(gconf);
}
static int parse_volume_options(GlusterConf *gconf, char *path)
{
char *p, *q;
if (!path) {
return -EINVAL;
}
/* volume */
p = q = path + strspn(path, "/");
p += strcspn(p, "/");
if (*p == '\0') {
return -EINVAL;
}
gconf->volname = g_strndup(q, p - q);
/* image */
p += strspn(p, "/");
if (*p == '\0') {
return -EINVAL;
}
gconf->image = g_strdup(p);
return 0;
}
/*
* file=gluster[+transport]://[server[:port]]/volname/image[?socket=...]
*
* 'gluster' is the protocol.
*
* 'transport' specifies the transport type used to connect to gluster
* management daemon (glusterd). Valid transport types are
* tcp, unix and rdma. If a transport type isn't specified, then tcp
* type is assumed.
*
* 'server' specifies the server where the volume file specification for
* the given volume resides. This can be either hostname, ipv4 address
* or ipv6 address. ipv6 address needs to be within square brackets [ ].
* If transport type is 'unix', then 'server' field should not be specifed.
* The 'socket' field needs to be populated with the path to unix domain
* socket.
*
* 'port' is the port number on which glusterd is listening. This is optional
* and if not specified, QEMU will send 0 which will make gluster to use the
* default port. If the transport type is unix, then 'port' should not be
* specified.
*
* 'volname' is the name of the gluster volume which contains the VM image.
*
* 'image' is the path to the actual VM image that resides on gluster volume.
*
* Examples:
*
* file=gluster://1.2.3.4/testvol/a.img
* file=gluster+tcp://1.2.3.4/testvol/a.img
* file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
* file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
* file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
* file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
* file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
* file=gluster+rdma://1.2.3.4:24007/testvol/a.img
*/
static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename)
{
URI *uri;
QueryParams *qp = NULL;
bool is_unix = false;
int ret = 0;
uri = uri_parse(filename);
if (!uri) {
return -EINVAL;
}
/* transport */
if (!strcmp(uri->scheme, "gluster")) {
gconf->transport = g_strdup("tcp");
} else if (!strcmp(uri->scheme, "gluster+tcp")) {
gconf->transport = g_strdup("tcp");
} else if (!strcmp(uri->scheme, "gluster+unix")) {
gconf->transport = g_strdup("unix");
is_unix = true;
} else if (!strcmp(uri->scheme, "gluster+rdma")) {
gconf->transport = g_strdup("rdma");
} else {
ret = -EINVAL;
goto out;
}
ret = parse_volume_options(gconf, uri->path);
if (ret < 0) {
goto out;
}
qp = query_params_parse(uri->query);
if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
ret = -EINVAL;
goto out;
}
if (is_unix) {
if (uri->server || uri->port) {
ret = -EINVAL;
goto out;
}
if (strcmp(qp->p[0].name, "socket")) {
ret = -EINVAL;
goto out;
}
gconf->server = g_strdup(qp->p[0].value);
} else {
gconf->server = g_strdup(uri->server);
gconf->port = uri->port;
}
out:
if (qp) {
query_params_free(qp);
}
uri_free(uri);
return ret;
}
static struct glfs *qemu_gluster_init(GlusterConf *gconf, const char *filename)
{
struct glfs *glfs = NULL;
int ret;
int old_errno;
ret = qemu_gluster_parseuri(gconf, filename);
if (ret < 0) {
error_report("Usage: file=gluster[+transport]://[server[:port]]/"
"volname/image[?socket=...]");
errno = -ret;
goto out;
}
glfs = glfs_new(gconf->volname);
if (!glfs) {
goto out;
}
ret = glfs_set_volfile_server(glfs, gconf->transport, gconf->server,
gconf->port);
if (ret < 0) {
goto out;
}
/*
* TODO: Use GF_LOG_ERROR instead of hard code value of 4 here when
* GlusterFS makes GF_LOG_* macros available to libgfapi users.
*/
ret = glfs_set_logging(glfs, "-", 4);
if (ret < 0) {
goto out;
}
ret = glfs_init(glfs);
if (ret) {
error_report("Gluster connection failed for server=%s port=%d "
"volume=%s image=%s transport=%s", gconf->server, gconf->port,
gconf->volname, gconf->image, gconf->transport);
goto out;
}
return glfs;
out:
if (glfs) {
old_errno = errno;
glfs_fini(glfs);
errno = old_errno;
}
return NULL;
}
static void qemu_gluster_complete_aio(void *opaque)
{
GlusterAIOCB *acb = (GlusterAIOCB *)opaque;
qemu_bh_delete(acb->bh);
acb->bh = NULL;
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",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = "filename",
.type = QEMU_OPT_STRING,
.help = "URL to the gluster image",
},
{ /* end of list */ }
},
};
static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
int bdrv_flags, Error **errp)
{
BDRVGlusterState *s = bs->opaque;
int open_flags = O_BINARY;
int ret = 0;
GlusterConf *gconf = g_malloc0(sizeof(GlusterConf));
QemuOpts *opts;
Error *local_err = NULL;
const char *filename;
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (error_is_set(&local_err)) {
qerror_report_err(local_err);
error_free(local_err);
ret = -EINVAL;
goto out;
}
filename = qemu_opt_get(opts, "filename");
s->glfs = qemu_gluster_init(gconf, filename);
if (!s->glfs) {
ret = -errno;
goto out;
}
if (bdrv_flags & BDRV_O_RDWR) {
open_flags |= O_RDWR;
} else {
open_flags |= O_RDONLY;
}
if ((bdrv_flags & BDRV_O_NOCACHE)) {
open_flags |= O_DIRECT;
}
s->fd = glfs_open(s->glfs, gconf->image, open_flags);
if (!s->fd) {
ret = -errno;
}
out:
qemu_opts_del(opts);
qemu_gluster_gconf_free(gconf);
if (!ret) {
return ret;
}
if (s->fd) {
glfs_close(s->fd);
}
if (s->glfs) {
glfs_fini(s->glfs);
}
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;
}
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,
QEMUOptionParameter *options, Error **errp)
{
struct glfs *glfs;
struct glfs_fd *fd;
int ret = 0;
int prealloc = 0;
int64_t total_size = 0;
GlusterConf *gconf = g_malloc0(sizeof(GlusterConf));
glfs = qemu_gluster_init(gconf, filename);
if (!glfs) {
ret = -errno;
goto out;
}
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++;
}
fd = glfs_creat(glfs, gconf->image,
O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR);
if (!fd) {
ret = -errno;
} else {
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;
}
}
out:
qemu_gluster_gconf_free(gconf);
if (glfs) {
glfs_fini(glfs);
}
return ret;
}
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 = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
size_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();
if (write) {
ret = glfs_pwritev_async(s->fd, qiov->iov, qiov->niov, offset, 0,
&gluster_finish_aiocb, acb);
} else {
ret = glfs_preadv_async(s->fd, qiov->iov, qiov->niov, offset, 0,
&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;
}
static int qemu_gluster_truncate(BlockDriverState *bs, int64_t offset)
{
int ret;
BDRVGlusterState *s = bs->opaque;
ret = glfs_ftruncate(s->fd, offset);
if (ret < 0) {
return -errno;
}
return 0;
}
static coroutine_fn int qemu_gluster_co_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 0);
}
static coroutine_fn int qemu_gluster_co_writev(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
{
return qemu_gluster_co_rw(bs, sector_num, nb_sectors, qiov, 1);
}
static coroutine_fn int qemu_gluster_co_flush_to_disk(BlockDriverState *bs)
{
int ret;
GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
acb->size = 0;
acb->ret = 0;
acb->coroutine = qemu_coroutine_self();
ret = glfs_fsync_async(s->fd, &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;
}
#ifdef CONFIG_GLUSTERFS_DISCARD
static coroutine_fn int qemu_gluster_co_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors)
{
int ret;
GlusterAIOCB *acb = g_slice_new(GlusterAIOCB);
BDRVGlusterState *s = bs->opaque;
size_t size = nb_sectors * BDRV_SECTOR_SIZE;
off_t offset = sector_num * BDRV_SECTOR_SIZE;
acb->size = 0;
acb->ret = 0;
acb->coroutine = qemu_coroutine_self();
ret = glfs_discard_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 int64_t qemu_gluster_getlength(BlockDriverState *bs)
{
BDRVGlusterState *s = bs->opaque;
int64_t ret;
ret = glfs_lseek(s->fd, 0, SEEK_END);
if (ret < 0) {
return -errno;
} else {
return ret;
}
}
static int64_t qemu_gluster_allocated_file_size(BlockDriverState *bs)
{
BDRVGlusterState *s = bs->opaque;
struct stat st;
int ret;
ret = glfs_fstat(s->fd, &st);
if (ret < 0) {
return -errno;
} else {
return st.st_blocks * 512;
}
}
static void qemu_gluster_close(BlockDriverState *bs)
{
BDRVGlusterState *s = bs->opaque;
if (s->fd) {
glfs_close(s->fd);
s->fd = NULL;
}
glfs_fini(s->glfs);
}
static int qemu_gluster_has_zero_init(BlockDriverState *bs)
{
/* GlusterFS volume could be backed by a block device */
return 0;
}
static QEMUOptionParameter qemu_gluster_create_options[] = {
{
.name = BLOCK_OPT_SIZE,
.type = OPT_SIZE,
.help = "Virtual disk size"
},
{
.name = BLOCK_OPT_PREALLOC,
.type = OPT_STRING,
.help = "Preallocation mode (allowed values: off, full)"
},
{ NULL }
};
static BlockDriver bdrv_gluster = {
.format_name = "gluster",
.protocol_name = "gluster",
.instance_size = sizeof(BDRVGlusterState),
.bdrv_needs_filename = true,
.bdrv_file_open = qemu_gluster_open,
.bdrv_close = qemu_gluster_close,
.bdrv_create = qemu_gluster_create,
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
.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_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,
};
static BlockDriver bdrv_gluster_tcp = {
.format_name = "gluster",
.protocol_name = "gluster+tcp",
.instance_size = sizeof(BDRVGlusterState),
.bdrv_needs_filename = true,
.bdrv_file_open = qemu_gluster_open,
.bdrv_close = qemu_gluster_close,
.bdrv_create = qemu_gluster_create,
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
.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_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,
};
static BlockDriver bdrv_gluster_unix = {
.format_name = "gluster",
.protocol_name = "gluster+unix",
.instance_size = sizeof(BDRVGlusterState),
.bdrv_needs_filename = true,
.bdrv_file_open = qemu_gluster_open,
.bdrv_close = qemu_gluster_close,
.bdrv_create = qemu_gluster_create,
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
.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_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,
};
static BlockDriver bdrv_gluster_rdma = {
.format_name = "gluster",
.protocol_name = "gluster+rdma",
.instance_size = sizeof(BDRVGlusterState),
.bdrv_needs_filename = true,
.bdrv_file_open = qemu_gluster_open,
.bdrv_close = qemu_gluster_close,
.bdrv_create = qemu_gluster_create,
.bdrv_getlength = qemu_gluster_getlength,
.bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
.bdrv_truncate = qemu_gluster_truncate,
.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_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,
};
static void bdrv_gluster_init(void)
{
bdrv_register(&bdrv_gluster_rdma);
bdrv_register(&bdrv_gluster_unix);
bdrv_register(&bdrv_gluster_tcp);
bdrv_register(&bdrv_gluster);
}
block_init(bdrv_gluster_init);