Commit f1c17521 authored Jan 07, 2016 by Paolo Bonzini

nbd-server: do not exit on failed memory allocation



The amount of memory allocated in nbd_co_receive_request is driven by the
NBD client (possibly a virtual machine).  Parallel I/O can cause the
server to allocate a large amount of memory; check for failures and
return ENOMEM in that case.

Cc: qemu-block@nongnu.org
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent eb38c3b6

block/block-backend.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1033,6 +1033,11 @@ void blk_set_guest_block_size(BlockBackend *blk, int align)
		blk->guest_block_size = align;
		}

		void blk_try_blockalign(BlockBackend blk, size_t size)
		{
		return qemu_try_blockalign(blk ? blk->bs : NULL, size);
		}

		void blk_blockalign(BlockBackend blk, size_t size)
		{
		return qemu_blockalign(blk ? blk->bs : NULL, size);

include/sysemu/block-backend.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -148,6 +148,7 @@ int blk_get_flags(BlockBackend *blk);
		int blk_get_max_transfer_length(BlockBackend *blk);
		int blk_get_max_iov(BlockBackend *blk);
		void blk_set_guest_block_size(BlockBackend *blk, int align);
		void blk_try_blockalign(BlockBackend blk, size_t size);
		void blk_blockalign(BlockBackend blk, size_t size);
		bool blk_op_is_blocked(BlockBackend blk, BlockOpType op, Error *errp);
		void blk_op_unblock(BlockBackend blk, BlockOpType op, Error reason);

nbd/server.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -836,7 +836,11 @@ static ssize_t nbd_co_receive_request(NBDRequest req, struct nbd_request reque
		goto out;
		}

		req->data = blk_blockalign(client->exp->blk, request->len);
		req->data = blk_try_blockalign(client->exp->blk, request->len);
		if (req->data == NULL) {
		rc = -ENOMEM;
		goto out;
		}
		}
		if (command == NBD_CMD_WRITE) {
		TRACE("Reading %u byte(s)", request->len);