The following patchset introduces a per-inode rpc wait queue to be used to synchronize layout gets and returns during their respective rpc prepare phase. Essentially, layout gets wait on layout segments marked as invalid, currently meaning there is a layout return in progress. It should be ok to send the layout get anyway but waiting avoids the race rather than having to possibly resolve it on the done path. In the future layout gets could insert the layout segment they ask for as "invalid" so that parallel layout gets would wait too. However, since the server may return a different segment than requested (bigger or smaller), there's no guarantee that the parallel layoutget will overlap the one in progress. Layout returns wait on layout segments while they are being used (e.g. for I/O operations). [PATCH 1/4] SQUASHME: pnfs-post-submit: remove take_ref and only_valid params from pnfs_has_layout [PATCH 2/4] pnfs: allow nfs4_proc_layoutget to sleep on invalid lsegs [PATCH 3/4] pnfs: allow nfs4_proc_layoutreturn to sleep on barrier [PATCH 4/4] SQUASHME: pnfs: get rid of lo_waitq -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
