xref: /freebsd/tools/regression/nfsmmap/README (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1$FreeBSD$
2These tests are intended to make sure that NFS's use of the
3b_{valid,dirty}{off,end} fields of struct buf is consistent with the
4VM system's use of the underlying VM pages.
5
6Test1:
7	Open the file and write into the file, creating a buf
8	with a valid range and a dirty range
9
10	Fsync, flushing the dirty range
11
12	Mmap and read the whole page.  Since only part of the page is
13	valid, the VM system must re-read the invalid parts of the
14	page.
15
16Test2:
17	This is the same as test1 without the fsync.  The VM system
18	should first write out the dirty range and then read the rest
19	of the page.  This is currently broken since the vnode_pager
20	doesn't use the original buf for its i/o and therefore the
21	information in b_dirtyoff, b_dirtyend is not available.
22