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authorEric Blake <eblake@redhat.com>2016-05-06 10:26:30 -0600
committerKevin Wolf <kwolf@redhat.com>2016-05-12 15:22:08 +0200
commit60cb2fa7eb5431d8996589ebc5dde865c602d54b (patch)
tree7434d1c58e0ec3033d8330a2b121349e6a2e7b53
parent983a1600504b1b78242b9da29b0d7018a6eb231d (diff)
block: Introduce byte-based aio read/write
blk_aio_readv() and blk_aio_writev() are annoying in that they can't access sub-sector granularity, and cannot pass flags. Also, they require the caller to pass redundant information about the size of the I/O (qiov->size in bytes must match nb_sectors in sectors). Add new blk_aio_preadv() and blk_aio_pwritev() functions to fix the flaws. The next few patches will upgrade callers, then finally delete the old interfaces. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/block-backend.c18
-rw-r--r--include/sysemu/block-backend.h8
2 files changed, 24 insertions, 2 deletions
diff --git a/block/block-backend.c b/block/block-backend.c
index f8f88a6d5f..6ac76d0176 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1,7 +1,7 @@
/*
* QEMU Block backends
*
- * Copyright (C) 2014 Red Hat, Inc.
+ * Copyright (C) 2014-2016 Red Hat, Inc.
*
* Authors:
* Markus Armbruster <armbru@redhat.com>,
@@ -998,6 +998,14 @@ BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num,
blk_aio_read_entry, 0, cb, opaque);
}
+BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ return blk_aio_prwv(blk, offset, qiov->size, qiov,
+ blk_aio_read_entry, flags, cb, opaque);
+}
+
BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque)
@@ -1011,6 +1019,14 @@ BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
blk_aio_write_entry, 0, cb, opaque);
}
+BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque)
+{
+ return blk_aio_prwv(blk, offset, qiov->size, qiov,
+ blk_aio_write_entry, flags, cb, opaque);
+}
+
BlockAIOCB *blk_aio_flush(BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque)
{
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 851376b5b0..73df1a677c 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -1,7 +1,7 @@
/*
* QEMU Block backends
*
- * Copyright (C) 2014 Red Hat, Inc.
+ * Copyright (C) 2014-2016 Red Hat, Inc.
*
* Authors:
* Markus Armbruster <armbru@redhat.com>,
@@ -110,9 +110,15 @@ int64_t blk_nb_sectors(BlockBackend *blk);
BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
+ QEMUIOVector *qiov, BdrvRequestFlags flags,
+ BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_flush(BlockBackend *blk,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *blk_aio_discard(BlockBackend *blk,