NFS: Don't hold the group lock when calling nfs_release_request()

That can deadlock if this is the last reference since
nfs_page_group_destroy() calls nfs_page_group_sync_on_bit().
Note that even if the page was removed from the subpage list,
the req->wb_head could still be pointing to the old head.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2017-09-09 15:31:28 -04:00
parent 5d2a9d9dac
commit 8b77484f2b

View file

@ -532,9 +532,9 @@ nfs_lock_and_join_requests(struct page *page)
} 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);
nfs_unroll_locks(inode, head, subreq);
nfs_unlock_and_release_request(subreq);
nfs_page_group_unlock(head);
nfs_unlock_and_release_request(head);
return ERR_PTR(-EIO);
}