From 6f838a4b73d9c85e498f94c28109dde0efc1cb9d Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Wed, 13 May 2020 13:05:27 +0200 Subject: [PATCH] block: Pull out bdrv_default_perms_for_storage() Right now, bdrv_format_default_perms() is used by format parents (generally). We want to switch to a model where most parents use a single BdrvChildClass, which then decides the permissions based on the child role. To do so, we have to split bdrv_format_default_perms() into separate functions for each such role. Note that bdrv_default_perms_for_storage() currently handles all DATA | METADATA children. A follow-up patch is going to split it further into one function for each case. Signed-off-by: Max Reitz Reviewed-by: Eric Blake Message-Id: <20200513110544.176672-18-mreitz@redhat.com> Signed-off-by: Kevin Wolf --- block.c | 71 ++++++++++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 46 insertions(+), 25 deletions(-) diff --git a/block.c b/block.c index b12222a471..5d17aa1cc3 100644 --- a/block.c +++ b/block.c @@ -2506,6 +2506,50 @@ static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c, *nshared = shared; } +static void bdrv_default_perms_for_storage(BlockDriverState *bs, BdrvChild *c, + const BdrvChildClass *child_class, + BdrvChildRole role, + BlockReopenQueue *reopen_queue, + uint64_t perm, uint64_t shared, + uint64_t *nperm, uint64_t *nshared) +{ + int flags; + + assert(child_class == &child_file || + (child_class == &child_of_bds && + (role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA)))); + + flags = bdrv_reopen_get_flags(reopen_queue, bs); + + /* + * Apart from the modifications below, the same permissions are + * forwarded and left alone as for filters + */ + bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue, + perm, shared, &perm, &shared); + + /* Format drivers may touch metadata even if the guest doesn't write */ + if (bdrv_is_writable_after_reopen(bs, reopen_queue)) { + perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; + } + + /* + * bs->file always needs to be consistent because of the metadata. We + * can never allow other users to resize or write to it. + */ + if (!(flags & BDRV_O_NO_IO)) { + perm |= BLK_PERM_CONSISTENT_READ; + } + shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); + + if (bs->open_flags & BDRV_O_INACTIVE) { + shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; + } + + *nperm = perm; + *nshared = shared; +} + void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, const BdrvChildClass *child_class, BdrvChildRole role, @@ -2517,31 +2561,8 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, assert(child_class == &child_backing || child_class == &child_file); if (!backing) { - int flags = bdrv_reopen_get_flags(reopen_queue, bs); - - /* Apart from the modifications below, the same permissions are - * forwarded and left alone as for filters */ - bdrv_filter_default_perms(bs, c, child_class, role, reopen_queue, - perm, shared, &perm, &shared); - - /* Format drivers may touch metadata even if the guest doesn't write */ - if (bdrv_is_writable_after_reopen(bs, reopen_queue)) { - perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; - } - - /* bs->file always needs to be consistent because of the metadata. We - * can never allow other users to resize or write to it. */ - if (!(flags & BDRV_O_NO_IO)) { - perm |= BLK_PERM_CONSISTENT_READ; - } - shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); - - if (bs->open_flags & BDRV_O_INACTIVE) { - shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; - } - - *nperm = perm; - *nshared = shared; + bdrv_default_perms_for_storage(bs, c, child_class, role, reopen_queue, + perm, shared, nperm, nshared); } else { bdrv_default_perms_for_cow(bs, c, child_class, role, reopen_queue, perm, shared, nperm, nshared); -- 2.11.4.GIT