block: introduce bdrv_can_set_read_only()

Introduce check function for setting read_only flags.  Will return < 0 on
error, with appropriate Error value set.  Does not alter any flags.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: e2bba34ac3bc76a0c42adc390413f358ae0566e8.1491597120.git.jcody@redhat.com
This commit is contained in:
Jeff Cody 2017-04-07 16:55:29 -04:00
parent 93ed524e3d
commit 45803a0396
2 changed files with 14 additions and 1 deletions

14
block.c
View File

@ -197,7 +197,7 @@ bool bdrv_is_read_only(BlockDriverState *bs)
return bs->read_only;
}
int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
{
/* Do not set read_only if copy_on_read is enabled */
if (bs->copy_on_read && read_only) {
@ -213,6 +213,18 @@ int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
return -EPERM;
}
return 0;
}
int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
{
int ret = 0;
ret = bdrv_can_set_read_only(bs, read_only, errp);
if (ret < 0) {
return ret;
}
bs->read_only = read_only;
return 0;
}

View File

@ -434,6 +434,7 @@ int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
int64_t sector_num, int nb_sectors, int *pnum);
bool bdrv_is_read_only(BlockDriverState *bs);
int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp);
int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp);
bool bdrv_is_sg(BlockDriverState *bs);
bool bdrv_is_inserted(BlockDriverState *bs);