From 7c85d9007d05436e71d2b805b96c1e36a8193bd4 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 13 Dec 2006 15:23:48 -0500 Subject: NFS: Fixup some outdated comments... Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 42 +----------------------------------------- 1 file changed, 1 insertion(+), 41 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index f983c51e05a..e9eff9376dc 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1,47 +1,7 @@ /* * linux/fs/nfs/write.c * - * Writing file data over NFS. - * - * We do it like this: When a (user) process wishes to write data to an - * NFS file, a write request is allocated that contains the RPC task data - * plus some info on the page to be written, and added to the inode's - * write chain. If the process writes past the end of the page, an async - * RPC call to write the page is scheduled immediately; otherwise, the call - * is delayed for a few seconds. - * - * Just like readahead, no async I/O is performed if wsize < PAGE_SIZE. - * - * Write requests are kept on the inode's writeback list. Each entry in - * that list references the page (portion) to be written. When the - * cache timeout has expired, the RPC task is woken up, and tries to - * lock the page. As soon as it manages to do so, the request is moved - * from the writeback list to the writelock list. - * - * Note: we must make sure never to confuse the inode passed in the - * write_page request with the one in page->inode. As far as I understand - * it, these are different when doing a swap-out. - * - * To understand everything that goes on here and in the NFS read code, - * one should be aware that a page is locked in exactly one of the following - * cases: - * - * - A write request is in progress. - * - A user process is in generic_file_write/nfs_update_page - * - A user process is in generic_file_read - * - * Also note that because of the way pages are invalidated in - * nfs_revalidate_inode, the following assertions hold: - * - * - If a page is dirty, there will be no read requests (a page will - * not be re-read unless invalidated by nfs_revalidate_inode). - * - If the page is not uptodate, there will be no pending write - * requests, and no process will be in nfs_update_page. - * - * FIXME: Interaction with the vmscan routines is not optimal yet. - * Either vmscan must be made nfs-savvy, or we need a different page - * reclaim concept that supports something like FS-independent - * buffer_heads with a b_ops-> field. + * Write file data over NFS. * * Copyright (C) 1996, 1997, Olaf Kirch */ -- cgit v1.2.3