From f1c17521e79df863a5771d96974fab0d07f02be0 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 7 Jan 2016 14:34:13 +0100 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini --- block/block-backend.c | 5 +++++ include/sysemu/block-backend.h | 1 + nbd/server.c | 6 +++++- 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/block/block-backend.c b/block/block-backend.c index f41d326b3c..e81375955f 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -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); diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index dc244760a1..1568554e3e 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -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); diff --git a/nbd/server.c b/nbd/server.c index c41af0debe..eead339a2c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -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);