diff options
| author | Eric Blake <eblake@redhat.com> | 2016-07-15 12:32:02 -0600 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2016-07-20 14:11:54 +0100 |
| commit | fb1a6de14ab353baa4bc3dfb777e662a26045ca9 (patch) | |
| tree | c9660b51c577459759693286876f1a0546d19a5d /block/nbd.c | |
| parent | 04ed95f4843281e292d93018d56d4b14705f9f2c (diff) | |
| download | qemu-fb1a6de14ab353baa4bc3dfb777e662a26045ca9.zip | |
nbd: Rely on block layer to break up large requests
Now that the block layer will honor max_transfer, we can simplify
our code to rely on that guarantee.
The readv code can call directly into nbd-client, just as the
writev code has done since commit 52a4650.
Interestingly enough, while qemu-io 'w 0 40m' splits into a 32M
and 8M transaction, 'w -z 0 40m' splits into two 16M and an 8M,
because the block layer caps the bounce buffer for writing zeroes
at 16M. When we later introduce support for NBD_CMD_WRITE_ZEROES,
we can get a full 32M zero write (or larger, if the client and
server negotiate that write zeroes can use a larger size than
ordinary writes).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1468607524-19021-5-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/nbd.c')
| -rw-r--r-- | block/nbd.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/block/nbd.c b/block/nbd.c index 08e5b67b2f..8a130787c5 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -349,12 +349,6 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, return ret; } -static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num, - int nb_sectors, QEMUIOVector *qiov) -{ - return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov); -} - static int nbd_co_flush(BlockDriverState *bs) { return nbd_client_co_flush(bs); @@ -450,7 +444,7 @@ static BlockDriver bdrv_nbd = { .instance_size = sizeof(BDRVNBDState), .bdrv_parse_filename = nbd_parse_filename, .bdrv_file_open = nbd_open, - .bdrv_co_readv = nbd_co_readv, + .bdrv_co_readv = nbd_client_co_readv, .bdrv_co_writev_flags = nbd_client_co_writev, .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, @@ -468,7 +462,7 @@ static BlockDriver bdrv_nbd_tcp = { .instance_size = sizeof(BDRVNBDState), .bdrv_parse_filename = nbd_parse_filename, .bdrv_file_open = nbd_open, - .bdrv_co_readv = nbd_co_readv, + .bdrv_co_readv = nbd_client_co_readv, .bdrv_co_writev_flags = nbd_client_co_writev, .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, @@ -486,7 +480,7 @@ static BlockDriver bdrv_nbd_unix = { .instance_size = sizeof(BDRVNBDState), .bdrv_parse_filename = nbd_parse_filename, .bdrv_file_open = nbd_open, - .bdrv_co_readv = nbd_co_readv, + .bdrv_co_readv = nbd_client_co_readv, .bdrv_co_writev_flags = nbd_client_co_writev, .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, |