From 228345bf5db8bc97d1c64f062e138d389065d1ab Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Sat, 21 Apr 2018 15:29:26 +0200 Subject: [PATCH] block: Support BDRV_REQ_WRITE_UNCHANGED in filters Update the rest of the filter drivers to support BDRV_REQ_WRITE_UNCHANGED. They already forward write request flags to their children, so we just have to announce support for it. This patch does not cover the replication driver because that currently does not support flags at all, and because it just grabs the WRITE permission for its children when it can, so we should be fine just submitting the incoming WRITE_UNCHANGED requests as normal writes. It also does not cover format drivers for similar reasons. They all use bdrv_format_default_perms() as their .bdrv_child_perm() implementation so they just always grab the WRITE permission for their file children whenever possible. In addition, it often would be difficult to ascertain whether incoming unchanging writes end up as unchanging writes in their files. So we just leave them as normal potentially changing writes. Signed-off-by: Max Reitz Reviewed-by: Stefan Hajnoczi Reviewed-by: Alberto Garcia Message-id: 20180421132929.21610-7-mreitz@redhat.com Reviewed-by: Kevin Wolf Signed-off-by: Max Reitz --- block/blkdebug.c | 9 +++++---- block/blkreplay.c | 3 +++ block/blkverify.c | 3 +++ block/copy-on-read.c | 10 ++++++---- block/mirror.c | 2 ++ block/raw-format.c | 9 +++++---- block/throttle.c | 6 ++++-- 7 files changed, 28 insertions(+), 14 deletions(-) diff --git a/block/blkdebug.c b/block/blkdebug.c index 053372c22e..526af2a808 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -398,10 +398,11 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, goto out; } - bs->supported_write_flags = BDRV_REQ_FUA & - bs->file->bs->supported_write_flags; - bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & - bs->file->bs->supported_zero_flags; + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | + (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | + ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & + bs->file->bs->supported_zero_flags); ret = -EINVAL; /* Set alignment overrides */ diff --git a/block/blkreplay.c b/block/blkreplay.c index fe5a9b4a98..b016dbeee7 100755 --- a/block/blkreplay.c +++ b/block/blkreplay.c @@ -35,6 +35,9 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED; + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED; + ret = 0; fail: return ret; diff --git a/block/blkverify.c b/block/blkverify.c index 754cc9e857..da97ee5927 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -141,6 +141,9 @@ static int blkverify_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED; + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED; + ret = 0; fail: qemu_opts_del(opts); diff --git a/block/copy-on-read.c b/block/copy-on-read.c index 823ec751c4..6a97208888 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -33,11 +33,13 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags, return -EINVAL; } - bs->supported_write_flags = BDRV_REQ_FUA & - bs->file->bs->supported_write_flags; + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | + (BDRV_REQ_FUA & + bs->file->bs->supported_write_flags); - bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & - bs->file->bs->supported_zero_flags; + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | + ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & + bs->file->bs->supported_zero_flags); return 0; } diff --git a/block/mirror.c b/block/mirror.c index 6aa38db114..a4197bb975 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1134,6 +1134,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs, mirror_top_bs->implicit = true; } mirror_top_bs->total_sectors = bs->total_sectors; + mirror_top_bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED; + mirror_top_bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED; bdrv_set_aio_context(mirror_top_bs, bdrv_get_aio_context(bs)); /* bdrv_append takes ownership of the mirror_top_bs reference, need to keep diff --git a/block/raw-format.c b/block/raw-format.c index a378547c99..fe33693a2d 100644 --- a/block/raw-format.c +++ b/block/raw-format.c @@ -415,10 +415,11 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, } bs->sg = bs->file->bs->sg; - bs->supported_write_flags = BDRV_REQ_FUA & - bs->file->bs->supported_write_flags; - bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & - bs->file->bs->supported_zero_flags; + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | + (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | + ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) & + bs->file->bs->supported_zero_flags); if (bs->probed && !bdrv_is_read_only(bs)) { fprintf(stderr, diff --git a/block/throttle.c b/block/throttle.c index 95ed06acd8..e298827f95 100644 --- a/block/throttle.c +++ b/block/throttle.c @@ -81,8 +81,10 @@ static int throttle_open(BlockDriverState *bs, QDict *options, if (!bs->file) { return -EINVAL; } - bs->supported_write_flags = bs->file->bs->supported_write_flags; - bs->supported_zero_flags = bs->file->bs->supported_zero_flags; + bs->supported_write_flags = bs->file->bs->supported_write_flags | + BDRV_REQ_WRITE_UNCHANGED; + bs->supported_zero_flags = bs->file->bs->supported_zero_flags | + BDRV_REQ_WRITE_UNCHANGED; return throttle_configure_tgm(bs, tgm, options, errp); } -- GitLab