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qemu/block/gluster.c
Paolo Bonzini 0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create 
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c).  So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.

Mostly done with the following semantic patch:

@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));

@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);

except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00

1081 lines
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/*
* GlusterFS backend for QEMU
*
* Copyright (C) 2012 Bharata B Rao <bharata@linux.vnet.ibm.com>
*
* 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 "qemu/osdep.h"
#include <glusterfs/api/glfs.h>
#include "block/block_int.h"
#include "qapi/error.h"
#include "qemu/uri.h"
typedef struct GlusterAIOCB {
int64_t size;
int ret;
QEMUBH *bh;
Coroutine *coroutine;
AioContext *aio_context;
} GlusterAIOCB;
typedef struct BDRVGlusterState {
struct glfs *glfs;
struct glfs_fd *fd;
bool supports_seek_data;
int debug_level;
} BDRVGlusterState;
typedef struct GlusterConf {
char *server;
int port;
char *volname;
char *image;
char *transport;
int debug_level;
} GlusterConf;
static void qemu_gluster_gconf_free(GlusterConf *gconf)
{
if (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 specified.
* 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 (!uri->scheme || !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 ? uri->server : "localhost");
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,
Error **errp)
{
struct glfs *glfs = NULL;
int ret;
int old_errno;
ret = qemu_gluster_parseuri(gconf, filename);
if (ret < 0) {
error_setg(errp, "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;
}
ret = glfs_set_logging(glfs, "-", gconf->debug_level);
if (ret < 0) {
goto out;
}
ret = glfs_init(glfs);
if (ret) {
error_setg_errno(errp, errno,
"Gluster connection failed for server=%s port=%d "
"volume=%s image=%s transport=%s", gconf->server,
gconf->port, gconf->volname, gconf->image,
gconf->transport);
/* glfs_init sometimes doesn't set errno although docs suggest that */
if (errno == 0)
errno = EINVAL;
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);
}
/*
* 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 = -errno; /* Read/Write failed */
} else {
acb->ret = -EIO; /* Partial read/write - fail it */
}
acb->bh = aio_bh_new(acb->aio_context, qemu_gluster_complete_aio, acb);
qemu_bh_schedule(acb->bh);
}
#define GLUSTER_OPT_FILENAME "filename"
#define GLUSTER_OPT_DEBUG "debug"
#define GLUSTER_DEBUG_DEFAULT 4
#define GLUSTER_DEBUG_MAX 9
/* TODO Convert to fine grained options */
static QemuOptsList runtime_opts = {
.name = "gluster",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = GLUSTER_OPT_FILENAME,
.type = QEMU_OPT_STRING,
.help = "URL to the gluster image",
},
{
.name = GLUSTER_OPT_DEBUG,
.type = QEMU_OPT_NUMBER,
.help = "Gluster log level, valid range is 0-9",
},
{ /* end of list */ }
},
};
static void qemu_gluster_parse_flags(int bdrv_flags, int *open_flags)
{
assert(open_flags != NULL);
*open_flags |= O_BINARY;
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;
}
}
/*
* Do SEEK_DATA/HOLE to detect if it is functional. Older broken versions of
* gfapi incorrectly return the current offset when SEEK_DATA/HOLE is used.
* - Corrected versions return -1 and set errno to EINVAL.
* - Versions that support SEEK_DATA/HOLE correctly, will return -1 and set
* errno to ENXIO when SEEK_DATA is called with a position of EOF.
*/
static bool qemu_gluster_test_seek(struct glfs_fd *fd)
{
off_t ret, eof;
eof = glfs_lseek(fd, 0, SEEK_END);
if (eof < 0) {
/* this should never occur */
return false;
}
/* this should always fail with ENXIO if SEEK_DATA is supported */
ret = glfs_lseek(fd, eof, SEEK_DATA);
return (ret < 0) && (errno == ENXIO);
}
static int qemu_gluster_open(BlockDriverState *bs, QDict *options,
int bdrv_flags, Error **errp)
{
BDRVGlusterState *s = bs->opaque;
int open_flags = 0;
int ret = 0;
GlusterConf *gconf = g_new0(GlusterConf, 1);
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 (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto out;
}
filename = qemu_opt_get(opts, GLUSTER_OPT_FILENAME);
s->debug_level = qemu_opt_get_number(opts, GLUSTER_OPT_DEBUG,
GLUSTER_DEBUG_DEFAULT);
if (s->debug_level < 0) {
s->debug_level = 0;
} else if (s->debug_level > GLUSTER_DEBUG_MAX) {
s->debug_level = GLUSTER_DEBUG_MAX;
}
gconf->debug_level = s->debug_level;
s->glfs = qemu_gluster_init(gconf, filename, errp);
if (!s->glfs) {
ret = -errno;
goto out;
}
#ifdef CONFIG_GLUSTERFS_XLATOR_OPT
/* Without this, if fsync fails for a recoverable reason (for instance,
* ENOSPC), gluster will dump its cache, preventing retries. This means
* almost certain data loss. Not all gluster versions support the
* 'resync-failed-syncs-after-fsync' key value, but there is no way to
* discover during runtime if it is supported (this api returns success for
* unknown key/value pairs) */
ret = glfs_set_xlator_option(s->glfs, "*-write-behind",
"resync-failed-syncs-after-fsync",
"on");
if (ret < 0) {
error_setg_errno(errp, errno, "Unable to set xlator key/value pair");
ret = -errno;
goto out;
}
#endif
qemu_gluster_parse_flags(bdrv_flags, &open_flags);
s->fd = glfs_open(s->glfs, gconf->image, open_flags);
if (!s->fd) {
ret = -errno;
}
s->supports_seek_data = qemu_gluster_test_seek(s->fd);
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;
}
typedef struct BDRVGlusterReopenState {
struct glfs *glfs;
struct glfs_fd *fd;
} BDRVGlusterReopenState;
static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
int ret = 0;
BDRVGlusterState *s;
BDRVGlusterReopenState *reop_s;
GlusterConf *gconf = NULL;
int open_flags = 0;
assert(state != NULL);
assert(state->bs != NULL);
s = state->bs->opaque;
state->opaque = g_new0(BDRVGlusterReopenState, 1);
reop_s = state->opaque;
qemu_gluster_parse_flags(state->flags, &open_flags);
gconf = g_new0(GlusterConf, 1);
gconf->debug_level = s->debug_level;
reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename, errp);
if (reop_s->glfs == NULL) {
ret = -errno;
goto exit;
}
#ifdef CONFIG_GLUSTERFS_XLATOR_OPT
ret = glfs_set_xlator_option(reop_s->glfs, "*-write-behind",
"resync-failed-syncs-after-fsync", "on");
if (ret < 0) {
error_setg_errno(errp, errno, "Unable to set xlator key/value pair");
ret = -errno;
goto exit;
}
#endif
reop_s->fd = glfs_open(reop_s->glfs, gconf->image, open_flags);
if (reop_s->fd == NULL) {
/* reops->glfs will be cleaned up in _abort */
ret = -errno;
goto exit;
}
exit:
/* state->opaque will be freed in either the _abort or _commit */
qemu_gluster_gconf_free(gconf);
return ret;
}
static void qemu_gluster_reopen_commit(BDRVReopenState *state)
{
BDRVGlusterReopenState *reop_s = state->opaque;
BDRVGlusterState *s = state->bs->opaque;
/* close the old */
if (s->fd) {
glfs_close(s->fd);
}
if (s->glfs) {
glfs_fini(s->glfs);
}
/* use the newly opened image / connection */
s->fd = reop_s->fd;
s->glfs = reop_s->glfs;
g_free(state->opaque);
state->opaque = NULL;
return;
}
static void qemu_gluster_reopen_abort(BDRVReopenState *state)
{
BDRVGlusterReopenState *reop_s = state->opaque;
if (reop_s == NULL) {
return;
}
if (reop_s->fd) {
glfs_close(reop_s->fd);
}
if (reop_s->glfs) {
glfs_fini(reop_s->glfs);
}
g_free(state->opaque);
state->opaque = NULL;
return;
}
#ifdef CONFIG_GLUSTERFS_ZEROFILL
static coroutine_fn int qemu_gluster_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset, int size, BdrvRequestFlags flags)
{
int ret;
GlusterAIOCB acb;
BDRVGlusterState *s = bs->opaque;
acb.size = size;
acb.ret = 0;
acb.coroutine = qemu_coroutine_self();
acb.aio_context = bdrv_get_aio_context(bs);
ret = glfs_zerofill_async(s->fd, offset, size, gluster_finish_aiocb, &acb);
if (ret < 0) {
return -errno;
}
qemu_coroutine_yield();
return acb.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,
QemuOpts *opts, Error **errp)
{
struct glfs *glfs;
struct glfs_fd *fd;
int ret = 0;
int prealloc = 0;
int64_t total_size = 0;
char *tmp = NULL;
GlusterConf *gconf = g_new0(GlusterConf, 1);
gconf->debug_level = qemu_opt_get_number_del(opts, GLUSTER_OPT_DEBUG,
GLUSTER_DEBUG_DEFAULT);
if (gconf->debug_level < 0) {
gconf->debug_level = 0;
} else if (gconf->debug_level > GLUSTER_DEBUG_MAX) {
gconf->debug_level = GLUSTER_DEBUG_MAX;
}
glfs = qemu_gluster_init(gconf, filename, errp);
if (!glfs) {
ret = -errno;
goto out;
}
total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
tmp = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
if (!tmp || !strcmp(tmp, "off")) {
prealloc = 0;
} else if (!strcmp(tmp, "full") &&
gluster_supports_zerofill()) {
prealloc = 1;
} else {
error_setg(errp, "Invalid preallocation mode: '%s'"
" or GlusterFS doesn't support zerofill API",
tmp);
ret = -EINVAL;
goto out;
}
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)) {
if (prealloc && qemu_gluster_zerofill(fd, 0, total_size)) {
ret = -errno;
}
} else {
ret = -errno;
}
if (glfs_close(fd) != 0) {
ret = -errno;
}
}
out:
g_free(tmp);
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;
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();
acb.aio_context = bdrv_get_aio_context(bs);
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) {
return -errno;
}
qemu_coroutine_yield();
return acb.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 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 coroutine_fn int qemu_gluster_co_flush_to_disk(BlockDriverState *bs)
{
int ret;
GlusterAIOCB acb;
BDRVGlusterState *s = bs->opaque;
acb.size = 0;
acb.ret = 0;
acb.coroutine = qemu_coroutine_self();
acb.aio_context = bdrv_get_aio_context(bs);
ret = glfs_fsync_async(s->fd, gluster_finish_aiocb, &acb);
if (ret < 0) {
ret = -errno;
goto error;
}
qemu_coroutine_yield();
if (acb.ret < 0) {
ret = acb.ret;
goto error;
}
return acb.ret;
error:
/* Some versions of Gluster (3.5.6 -> 3.5.8?) will not retain its cache
* after a fsync failure, so we have no way of allowing the guest to safely
* continue. Gluster versions prior to 3.5.6 don't retain the cache
* either, but will invalidate the fd on error, so this is again our only
* option.
*
* The 'resync-failed-syncs-after-fsync' xlator option for the
* write-behind cache will cause later gluster versions to retain its
* cache after error, so long as the fd remains open. However, we
* currently have no way of knowing if this option is supported.
*
* TODO: Once gluster provides a way for us to determine if the option
* is supported, bypass the closure and setting drv to NULL. */
qemu_gluster_close(bs);
bs->drv = NULL;
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;
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();
acb.aio_context = bdrv_get_aio_context(bs);
ret = glfs_discard_async(s->fd, offset, size, gluster_finish_aiocb, &acb);
if (ret < 0) {
return -errno;
}
qemu_coroutine_yield();
return acb.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 int qemu_gluster_has_zero_init(BlockDriverState *bs)
{
/* GlusterFS volume could be backed by a block device */
return 0;
}
/*
* Find allocation range in @bs around offset @start.
* May change underlying file descriptor's file offset.
* If @start is not in a hole, store @start in @data, and the
* beginning of the next hole in @hole, and return 0.
* If @start is in a non-trailing hole, store @start in @hole and the
* beginning of the next non-hole in @data, and return 0.
* If @start is in a trailing hole or beyond EOF, return -ENXIO.
* If we can't find out, return a negative errno other than -ENXIO.
*
* (Shamefully copied from raw-posix.c, only miniscule adaptions.)
*/
static int find_allocation(BlockDriverState *bs, off_t start,
off_t *data, off_t *hole)
{
BDRVGlusterState *s = bs->opaque;
off_t offs;
if (!s->supports_seek_data) {
return -ENOTSUP;
}
/*
* SEEK_DATA cases:
* D1. offs == start: start is in data
* D2. offs > start: start is in a hole, next data at offs
* D3. offs < 0, errno = ENXIO: either start is in a trailing hole
* or start is beyond EOF
* If the latter happens, the file has been truncated behind
* our back since we opened it. All bets are off then.
* Treating like a trailing hole is simplest.
* D4. offs < 0, errno != ENXIO: we learned nothing
*/
offs = glfs_lseek(s->fd, start, SEEK_DATA);
if (offs < 0) {
return -errno; /* D3 or D4 */
}
assert(offs >= start);
if (offs > start) {
/* D2: in hole, next data at offs */
*hole = start;
*data = offs;
return 0;
}
/* D1: in data, end not yet known */
/*
* SEEK_HOLE cases:
* H1. offs == start: start is in a hole
* If this happens here, a hole has been dug behind our back
* since the previous lseek().
* H2. offs > start: either start is in data, next hole at offs,
* or start is in trailing hole, EOF at offs
* Linux treats trailing holes like any other hole: offs ==
* start. Solaris seeks to EOF instead: offs > start (blech).
* If that happens here, a hole has been dug behind our back
* since the previous lseek().
* H3. offs < 0, errno = ENXIO: start is beyond EOF
* If this happens, the file has been truncated behind our
* back since we opened it. Treat it like a trailing hole.
* H4. offs < 0, errno != ENXIO: we learned nothing
* Pretend we know nothing at all, i.e. "forget" about D1.
*/
offs = glfs_lseek(s->fd, start, SEEK_HOLE);
if (offs < 0) {
return -errno; /* D1 and (H3 or H4) */
}
assert(offs >= start);
if (offs > start) {
/*
* D1 and H2: either in data, next hole at offs, or it was in
* data but is now in a trailing hole. In the latter case,
* all bets are off. Treating it as if it there was data all
* the way to EOF is safe, so simply do that.
*/
*data = start;
*hole = offs;
return 0;
}
/* D1 and H1 */
return -EBUSY;
}
/*
* Returns the allocation status of the specified sectors.
*
* If 'sector_num' is beyond the end of the disk image the return value is 0
* and 'pnum' is set to 0.
*
* 'pnum' is set to the number of sectors (including and immediately following
* the specified sector) that are known to be in the same
* allocated/unallocated state.
*
* 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
* beyond the end of the disk image it will be clamped.
*
* (Based on raw_co_get_block_status() from raw-posix.c.)
*/
static int64_t coroutine_fn qemu_gluster_co_get_block_status(
BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
BlockDriverState **file)
{
BDRVGlusterState *s = bs->opaque;
off_t start, data = 0, hole = 0;
int64_t total_size;
int ret = -EINVAL;
if (!s->fd) {
return ret;
}
start = sector_num * BDRV_SECTOR_SIZE;
total_size = bdrv_getlength(bs);
if (total_size < 0) {
return total_size;
} else if (start >= total_size) {
*pnum = 0;
return 0;
} else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
}
ret = find_allocation(bs, start, &data, &hole);
if (ret == -ENXIO) {
/* Trailing hole */
*pnum = nb_sectors;
ret = BDRV_BLOCK_ZERO;
} else if (ret < 0) {
/* No info available, so pretend there are no holes */
*pnum = nb_sectors;
ret = BDRV_BLOCK_DATA;
} else if (data == start) {
/* On a data extent, compute sectors to the end of the extent,
* possibly including a partial sector at EOF. */
*pnum = MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_SIZE));
ret = BDRV_BLOCK_DATA;
} else {
/* On a hole, compute sectors to the beginning of the next extent. */
assert(hole == start);
*pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);
ret = BDRV_BLOCK_ZERO;
}
*file = bs;
return ret | BDRV_BLOCK_OFFSET_VALID | start;
}
static QemuOptsList qemu_gluster_create_opts = {
.name = "qemu-gluster-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(qemu_gluster_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
{
.name = BLOCK_OPT_PREALLOC,
.type = QEMU_OPT_STRING,
.help = "Preallocation mode (allowed values: off, full)"
},
{
.name = GLUSTER_OPT_DEBUG,
.type = QEMU_OPT_NUMBER,
.help = "Gluster log level, valid range is 0-9",
},
{ /* end of list */ }
}
};
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_reopen_prepare = qemu_gluster_reopen_prepare,
.bdrv_reopen_commit = qemu_gluster_reopen_commit,
.bdrv_reopen_abort = qemu_gluster_reopen_abort,
.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_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
.bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
.create_opts = &qemu_gluster_create_opts,
};
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_reopen_prepare = qemu_gluster_reopen_prepare,
.bdrv_reopen_commit = qemu_gluster_reopen_commit,
.bdrv_reopen_abort = qemu_gluster_reopen_abort,
.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_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
.bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
.create_opts = &qemu_gluster_create_opts,
};
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_reopen_prepare = qemu_gluster_reopen_prepare,
.bdrv_reopen_commit = qemu_gluster_reopen_commit,
.bdrv_reopen_abort = qemu_gluster_reopen_abort,
.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_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
.bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
.create_opts = &qemu_gluster_create_opts,
};
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_reopen_prepare = qemu_gluster_reopen_prepare,
.bdrv_reopen_commit = qemu_gluster_reopen_commit,
.bdrv_reopen_abort = qemu_gluster_reopen_abort,
.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_pwrite_zeroes = qemu_gluster_co_pwrite_zeroes,
#endif
.bdrv_co_get_block_status = qemu_gluster_co_get_block_status,
.create_opts = &qemu_gluster_create_opts,
};
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);
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