Extend the current module interface to allow for block drivers to be loaded
dynamically on request.
The only block drivers that can be converted into modules are the drivers
that don't perform any init operation except for registering themselves. This
is why libiscsi has been disabled as a module.
All the necessary module information is located in a new structure found in
include/qemu/module_block.h
Signed-off-by: Marc Marí <mar...@redhat.com>
---
block.c | 73 +++++++++++++++++++++++++++++++++++--
configure | 2 +-
include/qemu/module.h | 3 ++
include/qemu/module_block.h | 89 +++++++++++++++++++++++++++++++++++++++++++++
util/module.c | 38 ++++++-------------
5 files changed, 174 insertions(+), 31 deletions(-)
create mode 100644 include/qemu/module_block.h
diff --git a/block.c b/block.c
index d088ee0..f24a624 100644
--- a/block.c
+++ b/block.c
@@ -27,6 +27,7 @@
#include "block/block_int.h"
#include "block/blockjob.h"
#include "qemu/error-report.h"
+#include "qemu/module_block.h"
#include "qemu/module.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qjson.h"
@@ -277,11 +278,30 @@ void bdrv_add_close_notifier(BlockDriverState *bs,
Notifier *notify)
BlockDriver *bdrv_find_format(const char *format_name)
{
BlockDriver *drv1;
+ int i;
+
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
if (!strcmp(drv1->format_name, format_name)) {
return drv1;
}
}
+
+ for (i = 0; i < ARRAY_SIZE(block_driver_module); ++i) {
+ if (!strcmp(block_driver_module[i].format_name, format_name)) {
+ block_module_load_one(block_driver_module[i].library_name);
+ /* Copying code is not nice, but this way the current discovery is
+ * not modified. Calling recursively could fail if the library
+ * has been deleted.
+ */
+ QLIST_FOREACH(drv1, &bdrv_drivers, list) {
+ if (!strcmp(drv1->format_name, format_name)) {
+ return drv1;
+ }
+ }
+ }
+ }
+
+
return NULL;
}
@@ -483,9 +503,15 @@ int get_tmp_filename(char *filename, int size)
*/
static BlockDriver *find_hdev_driver(const char *filename)
{
- int score_max = 0, score;
+ int score_max = 0, score, i;
BlockDriver *drv = NULL, *d;
+ for (i = 0; i < ARRAY_SIZE(block_driver_module); ++i) {
+ if (block_driver_module[i].has_probe_device) {
+ block_module_load_one(block_driver_module[i].library_name);
+ }
+ }
+
QLIST_FOREACH(d, &bdrv_drivers, list) {
if (d->bdrv_probe_device) {
score = d->bdrv_probe_device(filename);
@@ -507,6 +533,7 @@ BlockDriver *bdrv_find_protocol(const char *filename,
char protocol[128];
int len;
const char *p;
+ int i;
/* TODO Drivers without bdrv_file_open must be specified explicitly */
@@ -533,6 +560,7 @@ BlockDriver *bdrv_find_protocol(const char *filename,
len = sizeof(protocol) - 1;
memcpy(protocol, filename, len);
protocol[len] = '\0';
+
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
if (drv1->protocol_name &&
!strcmp(drv1->protocol_name, protocol)) {
@@ -540,6 +568,23 @@ BlockDriver *bdrv_find_protocol(const char *filename,
}
}
+ for (i = 0; i < ARRAY_SIZE(block_driver_module); ++i) {
+ if (block_driver_module[i].protocol_name &&
+ !strcmp(block_driver_module[i].protocol_name, protocol)) {
+ block_module_load_one(block_driver_module[i].library_name);
+ /* Copying code is not nice, but this way the current discovery is
+ * not modified. Calling recursively could fail if the library
+ * has been deleted.
+ */
+ QLIST_FOREACH(drv1, &bdrv_drivers, list) {
+ if (drv1->protocol_name &&
+ !strcmp(drv1->protocol_name, protocol)) {
+ return drv1;
+ }
+ }
+ }
+ }
+
error_setg(errp, "Unknown protocol '%s'", protocol);
return NULL;
}
@@ -561,9 +606,15 @@ BlockDriver *bdrv_find_protocol(const char *filename,
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
const char *filename)
{
- int score_max = 0, score;
+ int score_max = 0, score, i;
BlockDriver *drv = NULL, *d;
+ for (i = 0; i < ARRAY_SIZE(block_driver_module); ++i) {
+ if (block_driver_module[i].has_probe) {
+ block_module_load_one(block_driver_module[i].library_name);
+ }
+ }
+
QLIST_FOREACH(d, &bdrv_drivers, list) {
if (d->bdrv_probe) {
score = d->bdrv_probe(buf, buf_size, filename);
@@ -2783,7 +2834,7 @@ void bdrv_iterate_format(void (*it)(void *opaque, const
char *name),
{
BlockDriver *drv;
int count = 0;
- int i;
+ int i, n;
const char **formats = NULL;
QLIST_FOREACH(drv, &bdrv_drivers, list) {
@@ -2801,6 +2852,22 @@ void bdrv_iterate_format(void (*it)(void *opaque, const
char *name),
}
}
+ for (n = 0; n < ARRAY_SIZE(block_driver_module); ++n) {
+ if (block_driver_module[n].format_name) {
+ bool found = false;
+ int i = count;
+ while (formats && i && !found) {
+ found = !strcmp(formats[--i],
+ block_driver_module[n].format_name);
+ }
+
+ if (!found) {
+ formats = g_renew(const char *, formats, count + 1);
+ formats[count++] = block_driver_module[n].format_name;
+ }
+ }
+ }
+
qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
for (i = 0; i < count; i++) {
diff --git a/configure b/configure
index cd219d8..9fca9ee 100755
--- a/configure
+++ b/configure
@@ -4971,7 +4971,7 @@ if test "$bzip2" = "yes" ; then
fi
if test "$libiscsi" = "yes" ; then
- echo "CONFIG_LIBISCSI=m" >> $config_host_mak
+ echo "CONFIG_LIBISCSI=y" >> $config_host_mak
echo "LIBISCSI_CFLAGS=$libiscsi_cflags" >> $config_host_mak
echo "LIBISCSI_LIBS=$libiscsi_libs" >> $config_host_mak
fi
diff --git a/include/qemu/module.h b/include/qemu/module.h
index 72d9498..0ad4bb7 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -53,9 +53,12 @@ typedef enum {
#define qapi_init(function) module_init(function, MODULE_INIT_QAPI)
#define type_init(function) module_init(function, MODULE_INIT_QOM)
+#define block_module_load_one(lib) module_load_one("block-", lib);
+
void register_module_init(void (*fn)(void), module_init_type type);
void register_dso_module_init(void (*fn)(void), module_init_type type);
void module_call_init(module_init_type type);
+void module_load_one(const char *prefix, const char *lib_name);
#endif
diff --git a/include/qemu/module_block.h b/include/qemu/module_block.h
new file mode 100644
index 0000000..f1d389c
--- /dev/null
+++ b/include/qemu/module_block.h
@@ -0,0 +1,88 @@
+/*
+ * QEMU Block Module Infrastructure
+ *
+ * Copyright Red Hat, Inc. 2015
+ *
+ * Authors:
+ * Marc Mari <mar...@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_MODULE_BLOCK_H
+#define QEMU_MODULE_BLOCK_H
+
+#include "qemu-common.h"
+
+static const struct {
+ const char *format_name;
+ const char *protocol_name;
+ const char *library_name;
+ bool has_probe;
+ bool has_probe_device;
+} block_driver_module[] = {
+ {
+ .library_name = "curl",
+ .format_name = "http",
+ .protocol_name = "http",
+ },
+ {
+ .library_name = "curl",
+ .format_name = "https",
+ .protocol_name = "https",
+ },
+ {
+ .library_name = "curl",
+ .format_name = "ftp",
+ .protocol_name = "ftp",
+ },
+ {
+ .library_name = "curl",
+ .format_name = "ftps",
+ .protocol_name = "ftps",
+ },
+ {
+ .library_name = "curl",
+ .format_name = "tftp",
+ .protocol_name = "tftp",
+ },
+ {
+ .library_name = "rbd",
+ .format_name = "rbd",
+ .protocol_name = "rbd",
+ },
+ {
+ .library_name = "gluster",
+ .format_name = "gluster",
+ .protocol_name = "gluster",
+ },
+ {
+ .library_name = "gluster",
+ .format_name = "gluster",
+ .protocol_name = "gluster+tcp",
+ },
+ {
+ .library_name = "gluster",
+ .format_name = "gluster",
+ .protocol_name = "gluster+unix",
+ },
+ {
+ .library_name = "gluster",
+ .format_name = "gluster",
+ .protocol_name = "gluster+rdma",
+ },
+ {
+ .library_name = "ssh",
+ .format_name = "ssh",
+ .protocol_name = "ssh",
+ },
+ {
+ .library_name = "dmg",
+ .format_name = "dmg",
+ .has_probe = true,
+ },
+};
+
+#endif
\ No newline at end of file
diff --git a/util/module.c b/util/module.c
index 4bd4a94..992d317 100644
--- a/util/module.c
+++ b/util/module.c
@@ -91,14 +91,11 @@ void register_dso_module_init(void (*fn)(void),
module_init_type type)
QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
}
-static void module_load(module_init_type type);
-
void module_call_init(module_init_type type)
{
ModuleTypeList *l;
ModuleEntry *e;
- module_load(type);
l = find_type(type);
QTAILQ_FOREACH(e, l, node) {
@@ -149,6 +146,7 @@ static int module_load_file(const char *fname)
ret = -EINVAL;
} else {
QTAILQ_FOREACH(e, &dso_init_list, node) {
+ e->init();
register_module_init(e->init, e->type);
}
ret = 0;
@@ -163,14 +161,10 @@ out:
}
#endif
-static void module_load(module_init_type type)
+void module_load_one(const char *prefix, const char *lib_name)
{
#ifdef CONFIG_MODULES
char *fname = NULL;
- const char **mp;
- static const char *block_modules[] = {
- CONFIG_BLOCK_MODULES
- };
char *exec_dir;
char *dirs[3];
int i = 0;
@@ -181,15 +175,6 @@ static void module_load(module_init_type type)
return;
}
- switch (type) {
- case MODULE_INIT_BLOCK:
- mp = block_modules;
- break;
- default:
- /* no other types have dynamic modules for now*/
- return;
- }
-
exec_dir = qemu_get_exec_dir();
dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : "");
@@ -198,16 +183,15 @@ static void module_load(module_init_type type)
g_free(exec_dir);
exec_dir = NULL;
- for ( ; *mp; mp++) {
- for (i = 0; i < ARRAY_SIZE(dirs); i++) {
- fname = g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOSUF);
- ret = module_load_file(fname);
- g_free(fname);
- fname = NULL;
- /* Try loading until loaded a module file */
- if (!ret) {
- break;
- }
+ for (i = 0; i < ARRAY_SIZE(dirs); i++) {
+ fname = g_strdup_printf("%s/%s%s%s",
+ dirs[i], prefix, lib_name, HOST_DSOSUF);
+ ret = module_load_file(fname);
+ g_free(fname);
+ fname = NULL;
+ /* Try loading until loaded a module file */
+ if (!ret) {
+ break;
}
}
--
2.4.3
