From dac14a1dbe20e003215dacb8a3a1a7e4ca4e0ad0 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 19 Aug 2023 17:22:14 -0400 Subject: [PATCH] NFS: Fix a potential data corruption commit 88975a55969e11f26fe3846bf4fbf8e7dc8cbbd4 upstream. We must ensure that the subrequests are joined back into the head before we can retransmit a request. If the head was not on the commit lists, because the server wrote it synchronously, we still need to add it back to the retransmission list. Add a call that mirrors the effect of nfs_cancel_remove_inode() for O_DIRECT. Fixes: ed5d588fe47f ("NFS: Try to join page groups before an O_DIRECT retransmission") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- fs/nfs/direct.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index cf34d0c..3bb530d 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -474,13 +474,31 @@ out: return result; } +static void nfs_direct_add_page_head(struct list_head *list, + struct nfs_page *req) +{ + struct nfs_page *head = req->wb_head; + + if (!list_empty(&head->wb_list) || !nfs_lock_request(head)) + return; + if (!list_empty(&head->wb_list)) { + nfs_unlock_request(head); + return; + } + list_add(&head->wb_list, list); + kref_get(&head->wb_kref); + kref_get(&head->wb_kref); +} + static void nfs_direct_join_group(struct list_head *list, struct inode *inode) { struct nfs_page *req, *subreq; list_for_each_entry(req, list, wb_list) { - if (req->wb_head != req) + if (req->wb_head != req) { + nfs_direct_add_page_head(&req->wb_list, req); continue; + } subreq = req->wb_this_page; if (subreq == req) continue; -- 2.7.4