From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53583) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDFpH-00049P-QU for qemu-devel@nongnu.org; Wed, 15 Jun 2016 14:46:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bDFpG-00040E-3N for qemu-devel@nongnu.org; Wed, 15 Jun 2016 14:46:07 -0400 From: Colin Lord Date: Wed, 15 Jun 2016 14:40:55 -0400 Message-Id: <1466016055-31351-3-git-send-email-clord@redhat.com> In-Reply-To: <1466016055-31351-1-git-send-email-clord@redhat.com> References: <1466016055-31351-1-git-send-email-clord@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH 2/2] blockdev: Add dynamic module loading for block drivers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com, markmb@redhat.com, Colin Lord From: Marc Mari Extend the current module interface to allow for block drivers to be load= ed 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 Mar=C3=AD Signed-off-by: Colin Lord --- Makefile | 3 -- block.c | 86 +++++++++++++++++++++++++++++++++++++++++++++= ------ include/qemu/module.h | 3 ++ util/module.c | 37 ++++++---------------- 4 files changed, 90 insertions(+), 39 deletions(-) diff --git a/Makefile b/Makefile index 8f8b6a2..461187c 100644 --- a/Makefile +++ b/Makefile @@ -247,9 +247,6 @@ Makefile: $(version-obj-y) $(version-lobj-y) libqemustub.a: $(stub-obj-y) libqemuutil.a: $(util-obj-y) =20 -block-modules =3D $(foreach o,$(block-obj-m),"$(basename $(subst /,-,$o)= )",) NULL -util/module.o-cflags =3D -D'CONFIG_BLOCK_MODULES=3D$(block-modules)' - ###################################################################### =20 qemu-img.o: qemu-img-cmds.h diff --git a/block.c b/block.c index f54bc25..7a91434 100644 --- a/block.c +++ b/block.c @@ -26,6 +26,7 @@ #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/qbool.h" @@ -242,11 +243,29 @@ BlockDriverState *bdrv_new(void) BlockDriver *bdrv_find_format(const char *format_name) { BlockDriver *drv1; + size_t i; + QLIST_FOREACH(drv1, &bdrv_drivers, list) { if (!strcmp(drv1->format_name, format_name)) { return drv1; } } + + for (i =3D 0; i < ARRAY_SIZE(block_driver_modules); ++i) { + if (!strcmp(block_driver_modules[i].format_name, format_name)) { + block_module_load_one(block_driver_modules[i].library_name); + /* Copying code is not nice, but this way the current discov= ery is + * not modified. Calling recursively could fail if the libra= ry + * has been deleted. + */ + QLIST_FOREACH(drv1, &bdrv_drivers, list) { + if (!strcmp(drv1->format_name, format_name)) { + return drv1; + } + } + } + } + return NULL; } =20 @@ -447,8 +466,15 @@ int get_tmp_filename(char *filename, int size) static BlockDriver *find_hdev_driver(const char *filename) { int score_max =3D 0, score; + size_t i; BlockDriver *drv =3D NULL, *d; =20 + for (i =3D 0; i < ARRAY_SIZE(block_driver_modules); ++i) { + if (block_driver_modules[i].has_probe_device) { + block_module_load_one(block_driver_modules[i].library_name); + } + } + QLIST_FOREACH(d, &bdrv_drivers, list) { if (d->bdrv_probe_device) { score =3D d->bdrv_probe_device(filename); @@ -470,6 +496,7 @@ BlockDriver *bdrv_find_protocol(const char *filename, char protocol[128]; int len; const char *p; + size_t i; =20 /* TODO Drivers without bdrv_file_open must be specified explicitly = */ =20 @@ -496,6 +523,7 @@ BlockDriver *bdrv_find_protocol(const char *filename, len =3D sizeof(protocol) - 1; memcpy(protocol, filename, len); protocol[len] =3D '\0'; + QLIST_FOREACH(drv1, &bdrv_drivers, list) { if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { @@ -503,6 +531,23 @@ BlockDriver *bdrv_find_protocol(const char *filename= , } } =20 + for (i =3D 0; i < ARRAY_SIZE(block_driver_modules); ++i) { + if (block_driver_modules[i].protocol_name && + !strcmp(block_driver_modules[i].protocol_name, protocol)) { + block_module_load_one(block_driver_modules[i].library_name); + /* Copying code is not nice, but this way the current discov= ery is + * not modified. Calling recursively could fail if the libra= ry + * 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; } @@ -525,8 +570,15 @@ BlockDriver *bdrv_probe_all(const uint8_t *buf, int = buf_size, const char *filename) { int score_max =3D 0, score; + size_t i; BlockDriver *drv =3D NULL, *d; =20 + for (i =3D 0; i < ARRAY_SIZE(block_driver_modules); ++i) { + if (block_driver_modules[i].has_probe) { + block_module_load_one(block_driver_modules[i].library_name); + } + } + QLIST_FOREACH(d, &bdrv_drivers, list) { if (d->bdrv_probe) { score =3D d->bdrv_probe(buf, buf_size, filename); @@ -2738,26 +2790,42 @@ static int qsort_strcmp(const void *a, const void= *b) return strcmp(a, b); } =20 +static const char **add_format(const char **formats, int *count, + const char *format_name) +{ + int i; + + for (i =3D 0; i < *count; i++) { + if (!strcmp(formats[i], format_name)) { + return formats; + } + } + + *count +=3D 1; + formats =3D g_renew(const char *, formats, *count); + formats[*count] =3D format_name; + return formats; +} + void bdrv_iterate_format(void (*it)(void *opaque, const char *name), void *opaque) { BlockDriver *drv; int count =3D 0; int i; + size_t n; const char **formats =3D NULL; =20 QLIST_FOREACH(drv, &bdrv_drivers, list) { if (drv->format_name) { - bool found =3D false; - int i =3D count; - while (formats && i && !found) { - found =3D !strcmp(formats[--i], drv->format_name); - } + formats =3D add_format(formats, &count, drv->format_name); + } + } =20 - if (!found) { - formats =3D g_renew(const char *, formats, count + 1); - formats[count++] =3D drv->format_name; - } + for (n =3D 0; n < ARRAY_SIZE(block_driver_modules); ++n) { + if (block_driver_modules[n].format_name) { + formats =3D add_format(formats, &count, + block_driver_modules[n].format_name); } } =20 diff --git a/include/qemu/module.h b/include/qemu/module.h index 2370708..4729858 100644 --- a/include/qemu/module.h +++ b/include/qemu/module.h @@ -52,9 +52,12 @@ typedef enum { #define qapi_init(function) module_init(function, MODULE_INIT_QAPI) #define type_init(function) module_init(function, MODULE_INIT_QOM) =20 +#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); =20 void module_call_init(module_init_type type); +void module_load_one(const char *prefix, const char *lib_name); =20 #endif diff --git a/util/module.c b/util/module.c index ce058ae..dbc6e52 100644 --- a/util/module.c +++ b/util/module.c @@ -91,14 +91,11 @@ void register_dso_module_init(void (*fn)(void), modul= e_init_type type) QTAILQ_INSERT_TAIL(&dso_init_list, e, node); } =20 -static void module_load(module_init_type type); - void module_call_init(module_init_type type) { ModuleTypeList *l; ModuleEntry *e; =20 - module_load(type); l =3D find_type(type); =20 QTAILQ_FOREACH(e, l, node) { @@ -163,14 +160,10 @@ out: } #endif =20 -static void module_load(module_init_type type) +void module_load_one(const char *prefix, const char *lib_name) { #ifdef CONFIG_MODULES char *fname =3D NULL; - const char **mp; - static const char *block_modules[] =3D { - CONFIG_BLOCK_MODULES - }; char *exec_dir; char *dirs[3]; int i =3D 0; @@ -181,15 +174,6 @@ static void module_load(module_init_type type) return; } =20 - switch (type) { - case MODULE_INIT_BLOCK: - mp =3D block_modules; - break; - default: - /* no other types have dynamic modules for now*/ - return; - } - exec_dir =3D qemu_get_exec_dir(); dirs[i++] =3D g_strdup_printf("%s", CONFIG_QEMU_MODDIR); dirs[i++] =3D g_strdup_printf("%s/..", exec_dir ? : ""); @@ -198,16 +182,15 @@ static void module_load(module_init_type type) g_free(exec_dir); exec_dir =3D NULL; =20 - for ( ; *mp; mp++) { - for (i =3D 0; i < ARRAY_SIZE(dirs); i++) { - fname =3D g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOS= UF); - ret =3D module_load_file(fname); - g_free(fname); - fname =3D NULL; - /* Try loading until loaded a module file */ - if (!ret) { - break; - } + for (i =3D 0; i < ARRAY_SIZE(dirs); i++) { + fname =3D g_strdup_printf("%s/%s%s%s", + dirs[i], prefix, lib_name, HOST_DSOSUF); + ret =3D module_load_file(fname); + g_free(fname); + fname =3D NULL; + /* Try loading until loaded a module file */ + if (!ret) { + break; } } =20 --=20 2.5.5