The patch titled Subject: nfs: drop the incorrect assertion in nfs_swap_rw() has been added to the -mm mm-hotfixes-unstable branch. Its filename is nfs-drop-the-incorrect-assertion-in-nfs_swap_rw.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days

------------------------------------------------------ From: Christoph Hellwig hch@lst.de Subject: nfs: drop the incorrect assertion in nfs_swap_rw() Date: Tue, 18 Jun 2024 18:56:47 +1200

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 hch@lst.de Signed-off-by: Barry Song v-songbaohua@oppo.com Reported-by: Christoph Hellwig hch@lst.de Closes: https://lore.kernel.org/linux-mm/20240617053201.GA16852@lst.de/ Cc: NeilBrown neilb@suse.de Cc: Anna Schumaker anna@kernel.org Cc: Steve French sfrench@samba.org Cc: Trond Myklebust trondmy@kernel.org Cc: Chuanhua Han hanchuanhua@oppo.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Chris Li chrisl@kernel.org Cc: "Huang, Ying" ying.huang@intel.com Cc: Jeff Layton jlayton@kernel.org Cc: Matthew Wilcox willy@infradead.org Cc: Martin Wege martin.l.wege@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/nfs/direct.c | 2 -- 1 file changed, 2 deletions(-)

--- a/fs/nfs/direct.c~nfs-drop-the-incorrect-assertion-in-nfs_swap_rw +++ a/fs/nfs/direct.c @@ -141,8 +141,6 @@ int nfs_swap_rw(struct kiocb *iocb, stru { 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 _

Patches currently in -mm which might be from hch@lst.de are

nfs-drop-the-incorrect-assertion-in-nfs_swap_rw.patch nfs-fix-nfs_swap_rw-for-large-folio-swap.patch