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: Weston Andros Adamson <dros@primarydata.com>
This commit is contained in:
Weston Andros Adamson 2014-09-05 16:34:29 -04:00 committed by Tom Haynes
parent 180bb5ec06
commit 309a1d65b1

View File

@ -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));
/* keep track of how many bytes this group covers */
total_bytes += subreq->wb_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