From 54a32bfec140e03ebb19863db944b1c81e4df25e Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 3 Aug 2017 17:02:58 +0200 Subject: [PATCH] block: Allow reopen rw without BDRV_O_ALLOW_RDWR BDRV_O_ALLOW_RDWR is a flag that tells whether qemu can internally reopen a node read-write temporarily because the user requested read-write for the top-level image, but qemu decided that read-only is enough for this node (a backing file). bdrv_reopen() is different, it is also used for cases where the user changed their mind and wants to update the options. There is no reason to forbid making a node read-write in that case. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Jeff Cody Reviewed-by: John Snow --- block.c | 11 +++++++---- include/block/block.h | 3 ++- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index ab908cdc50..2711c3dd3b 100644 --- a/block.c +++ b/block.c @@ -246,7 +246,8 @@ bool bdrv_is_writable(BlockDriverState *bs) return !bdrv_is_read_only(bs) && !(bs->open_flags & BDRV_O_INACTIVE); } -int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) +int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, + bool ignore_allow_rdw, Error **errp) { /* Do not set read_only if copy_on_read is enabled */ if (bs->copy_on_read && read_only) { @@ -256,7 +257,9 @@ int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) } /* Do not clear read_only if it is prohibited */ - if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR)) { + if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) && + !ignore_allow_rdw) + { error_setg(errp, "Node '%s' is read only", bdrv_get_device_or_node_name(bs)); return -EPERM; @@ -269,7 +272,7 @@ 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); + ret = bdrv_can_set_read_only(bs, read_only, false, errp); if (ret < 0) { return ret; } @@ -2907,7 +2910,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is * not set, or if the BDS still has copy_on_read enabled */ read_only = !(reopen_state->flags & BDRV_O_RDWR); - ret = bdrv_can_set_read_only(reopen_state->bs, read_only, &local_err); + ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err); if (local_err) { error_propagate(errp, local_err); goto error; diff --git a/include/block/block.h b/include/block/block.h index 34770bb33a..ab80195378 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -436,7 +436,8 @@ int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, bool bdrv_is_read_only(BlockDriverState *bs); bool bdrv_is_writable(BlockDriverState *bs); -int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, Error **errp); +int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, + bool ignore_allow_rdw, 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);