Re: [Libguestfs] [libnbd PATCH v2 1/5] lib: Refactor state event into command_common
On Tue, May 21, 2019 at 10:15:48PM -0500, Eric Blake wrote:
The next patch wants to make queuing commands smarter; rather than
duplicating the logic at each command's call site, it's better to
centralize things in command_common, and to also make this helper
routine visible for use in NBD_CMD_DISC.
There's a few problems with this patch.
To avoid leaking symbols -- even though we have a linker script, not
all future platforms are expected to support it -- global symbols
which are not exported should be called nbd_internal_*. So
command_common should be nbd_internal_command_common.
The bigger problem is:
@@ -505,8 +495,5 @@ nbd_unlocked_aio_block_status (struct
nbd_connection *conn,
cmd->extent_fn = extent;
cmd->extent_id = id;
- if (nbd_internal_run (conn->h, conn, cmd_issue) == -1)
- return -1;
-
return cmd->handle;
This changes the semantics of the function because the cmd->extent_*
fields are set too late. (Yes, command_common is rather ad hoc :-)
Rich.
--
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