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authorKevin Wolf <kwolf@redhat.com>2019-03-22 13:45:23 +0100
committerKevin Wolf <kwolf@redhat.com>2019-03-26 11:37:51 +0100
commit738301e11758171defaa5a5237d584f8226af89f (patch)
tree35052b7dbe20d0e796a3c3df9c7da02407f65cc3 /include
parent80f5c33ff31eb9333f5036ee278fb1483fb4ff41 (diff)
file-posix: Support BDRV_REQ_NO_FALLBACK for zero writes
We know that the kernel implements a slow fallback code path for BLKZEROOUT, so if BDRV_REQ_NO_FALLBACK is given, we shouldn't call it. The other operations we call in the context of .bdrv_co_pwrite_zeroes should usually be quick, so no modification should be needed for them. If we ever notice that there are additional problematic cases, we can still make these conditional as well. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'include')
-rw-r--r--include/block/raw-aio.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h
index 6799614e56..ba223dd1f1 100644
--- a/include/block/raw-aio.h
+++ b/include/block/raw-aio.h
@@ -40,6 +40,7 @@
/* AIO flags */
#define QEMU_AIO_MISALIGNED 0x1000
#define QEMU_AIO_BLKDEV 0x2000
+#define QEMU_AIO_NO_FALLBACK 0x4000
/* linux-aio.c - Linux native implementation */