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-bl...@nongnu.org
Reviewed-by: Max Reitz <mre...@redhat.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
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 f41d326..e813759 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 dc24476..1568554 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 c41af0d..eead339 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);
--
1.8.3.1
