From 54e7d59841dab977f6cb1183d658b1b82c9f4e94 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 18 Jun 2024 18:56:47 +1200 Subject: [PATCH] nfs: drop the incorrect assertion in nfs_swap_rw() Since commit 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space"), we can plug multiple pages then unplug them all together. That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it actually equals the size of iov_iter_npages(iter, INT_MAX). Note this issue has nothing to do with large folios as we don't support THP_SWPOUT to non-block devices. [v-songbaohua@oppo.com: figure out the cause and correct the commit message] Link: https://lkml.kernel.org/r/20240618065647.21791-1-21cnbao@gmail.com Fixes: 2282679fb20b ("mm: submit multipage write for SWP_FS_OPS swap-space") Signed-off-by: Christoph Hellwig Signed-off-by: Barry Song Closes: https://lore.kernel.org/linux-mm/20240617053201.GA16852@lst.de/ Reviewed-by: Martin Wege Cc: NeilBrown Cc: Anna Schumaker Cc: Steve French Cc: Trond Myklebust Cc: Chuanhua Han Cc: Ryan Roberts Cc: Chris Li Cc: "Huang, Ying" Cc: Jeff Layton Cc: Matthew Wilcox Cc: Signed-off-by: Andrew Morton --- fs/nfs/direct.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index bb2f583eb28b..90079ca134dd 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -141,8 +141,6 @@ int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter) { ssize_t ret; - VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE); - if (iov_iter_rw(iter) == READ) ret = nfs_file_direct_read(iocb, iter, true); else