1These tests are intended to make sure that NFS's use of the 2b_{valid,dirty}{off,end} fields of struct buf is consistent with the 3VM system's use of the underlying VM pages. 4 5Test1: 6 Open the file and write into the file, creating a buf 7 with a valid range and a dirty range 8 9 Fsync, flushing the dirty range 10 11 Mmap and read the whole page. Since only part of the page is 12 valid, the VM system must re-read the invalid parts of the 13 page. 14 15Test2: 16 This is the same as test1 without the fsync. The VM system 17 should first write out the dirty range and then read the rest 18 of the page. This is currently broken since the vnode_pager 19 doesn't use the original buf for its i/o and therefore the 20 information in b_dirtyoff, b_dirtyend is not available. 21