From 1e89d0f9bed7e95278d151cf6308cafbba8dae9f Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 1 Feb 2019 20:29:18 +0100 Subject: [PATCH] block: Add bdrv_dirname() 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 Message-id: 20190201192935.18394-15-mreitz@redhat.com Signed-off-by: Max Reitz --- block.c | 27 +++++++++++++++++++++++++++ include/block/block.h | 1 + include/block/block_int.h | 7 +++++++ 3 files changed, 35 insertions(+) diff --git a/block.c b/block.c index d14ce1c98c..9f655c0fd6 100644 --- a/block.c +++ b/block.c @@ -5715,6 +5715,33 @@ 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); + } + + bdrv_refresh_filename(bs); + 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 diff --git a/include/block/block.h b/include/block/block.h index 42cc38f598..5b5cf868df 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -491,6 +491,7 @@ 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 dd7276cde2..e4d4817ea6 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -141,6 +141,13 @@ 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_preadv)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,