Commit 309a1d65 authored by Weston Andros Adamson's avatar Weston Andros Adamson Committed by Tom Haynes
Browse files

nfs: handle overlapping reqs in lock_and_join 



This is needed for mirrored DS support, where multuple requests
cover the same range.

Signed-off-by: default avatarWeston Andros Adamson <dros@primarydata.com>
parent 180bb5ec

fs/nfs/write.c

+11 −6
Original line number Diff line number Diff line
@@ -473,13 +473,18 @@ try_again: 
	do {

		/*

		 * Subrequests are always contiguous, non overlapping

		 * and in order. If not, it's a programming error.

		 * and in order - but may be repeated (mirrored writes).

		 */

		WARN_ON_ONCE(subreq->wb_offset !=

		     (head->wb_offset + total_bytes));



		if (subreq->wb_offset == (head->wb_offset + total_bytes)) {

			/* keep track of how many bytes this group covers */

			total_bytes += subreq->wb_bytes;

		} else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset ||

			    ((subreq->wb_offset + subreq->wb_bytes) >

			     (head->wb_offset + total_bytes)))) {

			nfs_page_group_unlock(head);

			spin_unlock(&inode->i_lock);

			return ERR_PTR(-EIO);

		}



		if (!nfs_lock_request(subreq)) {

			/* releases page group bit lock and