From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39699) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cqAIh-0001lx-9u for qemu-devel@nongnu.org; Mon, 20 Mar 2017 23:17:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cqAIg-0000Z8-Cu for qemu-devel@nongnu.org; Mon, 20 Mar 2017 23:17:35 -0400 From: Fam Zheng Date: Tue, 21 Mar 2017 11:16:23 +0800 Message-Id: <20170321031635.22123-5-famz@redhat.com> In-Reply-To: <20170321031635.22123-1-famz@redhat.com> References: <20170321031635.22123-1-famz@redhat.com> Subject: [Qemu-devel] [PATCH RFC 04/16] block: Propagate BLK_PERM_AIO_CONTEXT_CHANGE down the graph List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Stefan Hajnoczi , Kevin Wolf , Max Reitz , qemu-block@nongnu.org bdrv_set_aio_context can take care of children recursively, so it is okay to pass down the perm. Signed-off-by: Fam Zheng --- block.c | 18 ++++++++++-------- block/vvfat.c | 2 +- 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index ae9327b..0190087 100644 --- a/block.c +++ b/block.c @@ -1670,7 +1670,8 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \ | BLK_PERM_WRITE \ | BLK_PERM_WRITE_UNCHANGED \ - | BLK_PERM_RESIZE) + | BLK_PERM_RESIZE \ + | BLK_PERM_AIO_CONTEXT_CHANGE) #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH) void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, @@ -1713,21 +1714,22 @@ void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, perm |= BLK_PERM_CONSISTENT_READ; shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); } else { - /* We want consistent read from backing files if the parent needs it. + /* We want consistent read and aio context change from backing files if + * the parent needs it. * No other operations are performed on backing files. */ - perm &= BLK_PERM_CONSISTENT_READ; + perm &= BLK_PERM_CONSISTENT_READ | BLK_PERM_AIO_CONTEXT_CHANGE; - /* If the parent can deal with changing data, we're okay with a + /* If the parent can deal with changing aio context, we're okay too; + * If the parent can deal with changing data, we're okay with a * writable and resizable backing file. */ /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */ + shared &= BLK_PERM_AIO_CONTEXT_CHANGE | BLK_PERM_WRITE; if (shared & BLK_PERM_WRITE) { - shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; - } else { - shared = 0; + shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; } shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | - BLK_PERM_WRITE_UNCHANGED; + BLK_PERM_WRITE_UNCHANGED | BLK_PERM_AIO_CONTEXT_CHANGE; } *nperm = perm; diff --git a/block/vvfat.c b/block/vvfat.c index af5153d..70ce452 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -3080,7 +3080,7 @@ static void vvfat_child_perm(BlockDriverState *bs, BdrvChild *c, if (c == s->qcow) { /* This is a private node, nobody should try to attach to it */ *nperm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE; - *nshared = BLK_PERM_WRITE_UNCHANGED; + *nshared = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_AIO_CONTEXT_CHANGE; } else { /* The backing file is there so 'commit' can use it. vvfat doesn't * access it in any way. */ -- 2.9.3