block: limited request size in write zeroes unsupported path
commit095e4fa4b56cf511cb41005872eeace9a2f24582
authorPeter Lieven <pl@kamp.de>
Mon, 5 Jan 2015 11:29:49 +0000 (5 12:29 +0100)
committerStefan Hajnoczi <stefanha@redhat.com>
Tue, 13 Jan 2015 13:43:29 +0000 (13 13:43 +0000)
tree929757fee681f1d76a0b744238c88d5900e9144d
parent51a2219bdceed16e81c6e2e2f08aed39c579728f
block: limited request size in write zeroes unsupported path

If bs->bl.max_write_zeroes is large and we end up in the unsupported
path we might allocate a lot of memory for the iovector and/or even
generate an oversized requests.

Fix this by limiting the request by the minimum of the reported
maximum transfer size or 16MB (32768 sectors).

Reported-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-id: 1420457389-16332-1-git-send-email-pl@kamp.de
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block.c