From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53280) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eiiYs-0000hk-B6 for qemu-devel@nongnu.org; Mon, 05 Feb 2018 10:20:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eiiYr-0007qK-Bt for qemu-devel@nongnu.org; Mon, 05 Feb 2018 10:20:02 -0500 From: Max Reitz Date: Mon, 5 Feb 2018 16:18:20 +0100 Message-Id: <20180205151835.20812-12-mreitz@redhat.com> In-Reply-To: <20180205151835.20812-1-mreitz@redhat.com> References: <20180205151835.20812-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v8 11/26] block: Add bdrv_dirname() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Alberto Garcia , Kevin Wolf This function may be implemented by block drivers to derive a directory name from a BDS. Concatenating this g_free()-able string with a relative filename must result in a valid (not necessarily existing) filename, so this is a function that should generally be not implemented by format drivers, because this is protocol-specific. If a BDS's driver does not implement this function, bdrv_dirname() will fall through to the BDS's file if it exists. If it does not, the exact_filename field will be used to generate a directory name. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia --- include/block/block.h | 1 + include/block/block_int.h | 7 +++++++ block.c | 26 ++++++++++++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index fafb8a6a7a..1983055916 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -485,6 +485,7 @@ char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); char *bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, Error **errp); +char *bdrv_dirname(BlockDriverState *bs, Error **errp); int path_has_protocol(const char *path); int path_is_absolute(const char *path); diff --git a/include/block/block_int.h b/include/block/block_int.h index b5c124fcbd..8b0413e3df 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -135,6 +135,13 @@ struct BlockDriver { void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options); + /* + * Returns an allocated string which is the directory name of this BDS: It + * will be used to make relative filenames absolute by prepending this + * function's return value to them. + */ + char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp); + /* aio */ BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, diff --git a/block.c b/block.c index 06ee694ac5..8957a3d4dc 100644 --- a/block.c +++ b/block.c @@ -5153,6 +5153,32 @@ void bdrv_refresh_filename(BlockDriverState *bs) } } +char *bdrv_dirname(BlockDriverState *bs, Error **errp) +{ + BlockDriver *drv = bs->drv; + + if (!drv) { + error_setg(errp, "Node '%s' is ejected", bs->node_name); + return NULL; + } + + if (drv->bdrv_dirname) { + return drv->bdrv_dirname(bs, errp); + } + + if (bs->file) { + return bdrv_dirname(bs->file->bs, errp); + } + + if (bs->exact_filename[0] != '\0') { + return path_combine(bs->exact_filename, ""); + } + + error_setg(errp, "Cannot generate a base directory for %s nodes", + drv->format_name); + return NULL; +} + /* * Hot add/remove a BDS's child. So the user can take a child offline when * it is broken and take a new child online -- 2.14.3