NFS: Fix up nfs_page_group_covers_page()
Fix up the test in nfs_page_group_covers_page(). The simplest implementation
is to check that we have a set of intersecting or contiguous subrequests
that connect page offset 0 to nfs_page_length(req->wb_page).
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0f418d8..759e37d 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -243,9 +243,6 @@ nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
{
struct nfs_page *req;
- WARN_ON_ONCE(head != head->wb_head);
- WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags));
-
req = head;
do {
if (page_offset >= req->wb_pgbase &&
@@ -273,18 +270,15 @@ static bool nfs_page_group_covers_page(struct nfs_page *req)
nfs_page_group_lock(req);
- do {
+ for (;;) {
tmp = nfs_page_group_search_locked(req->wb_head, pos);
- if (tmp) {
- /* no way this should happen */
- WARN_ON_ONCE(tmp->wb_pgbase != pos);
- pos += tmp->wb_bytes - (pos - tmp->wb_pgbase);
- }
- } while (tmp && pos < len);
+ if (!tmp)
+ break;
+ pos = tmp->wb_pgbase + tmp->wb_bytes;
+ }
nfs_page_group_unlock(req);
- WARN_ON_ONCE(pos > len);
- return pos == len;
+ return pos >= len;
}
/* We can set the PG_uptodate flag if we see that a write request