diff --git a/fs/nfs/read.c b/fs/nfs/read.c index 53d5b83611ce..e818a475ca64 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -130,7 +130,6 @@ static void nfs_page_group_set_uptodate(struct nfs_page *req) SetPageUptodate(req->wb_page); } -/* Note io was page aligned */ static void nfs_read_completion(struct nfs_pgio_header *hdr) { unsigned long bytes = 0; @@ -140,14 +139,25 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr) while (!list_empty(&hdr->pages)) { struct nfs_page *req = nfs_list_entry(hdr->pages.next); struct page *page = req->wb_page; + unsigned long start = req->wb_pgbase; + unsigned long end = req->wb_pgbase + req->wb_bytes; if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) { - if (bytes > hdr->good_bytes) - zero_user(page, 0, PAGE_SIZE); - else if (hdr->good_bytes - bytes < PAGE_SIZE) - zero_user_segment(page, - hdr->good_bytes & ~PAGE_MASK, - PAGE_SIZE); + /* note: regions of the page not covered by a + * request are zeroed in nfs_readpage_async / + * readpage_async_filler */ + if (bytes > hdr->good_bytes) { + /* nothing in this request was good, so zero + * the full extent of the request */ + zero_user_segment(page, start, end); + + } else if (hdr->good_bytes - bytes < req->wb_bytes) { + /* part of this request has good bytes, but + * not all. zero the bad bytes */ + start += hdr->good_bytes - bytes; + WARN_ON(start < req->wb_pgbase); + zero_user_segment(page, start, end); + } } bytes += req->wb_bytes; if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {