6.9-stable review patch. If anyone has any objections, please let me know.
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From: Christoph Hellwig hch@lst.de
commit 54e7d59841dab977f6cb1183d658b1b82c9f4e94 upstream.
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 Closes: https://lore.kernel.org/linux-mm/20240617053201.GA16852@lst.de/ Reviewed-by: Martin Wege martin.l.wege@gmail.com 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: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/direct.c | 2 -- 1 file changed, 2 deletions(-)
--- a/fs/nfs/direct.c +++ b/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