From 53b776c77aca99b663a5512a04abc27670d61058 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 26 Apr 2021 21:16:16 +0100 Subject: [PATCH] netfs: Miscellaneous fixes Fix some miscellaneous things in the new netfs lib[1]: (1) The kerneldoc for netfs_readpage() shouldn't say netfs_page(). (2) netfs_readpage() can get an integer overflow on 32-bit when it multiplies page_index(page) by PAGE_SIZE. It should use page_file_offset() instead. (3) netfs_write_begin() should use page_offset() to avoid the same overflow. Note that netfs_readpage() needs to use page_file_offset() rather than page_offset() as it may see swap-over-NFS. Reported-by: Matthew Wilcox (Oracle) Signed-off-by: David Howells Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Jeff Layton Link: https://lore.kernel.org/r/161789062190.6155.12711584466338493050.stgit@warthog.procyon.org.uk/ [1] --- fs/netfs/read_helper.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c index 1d3b50c5db6d..193841d03de0 100644 --- a/fs/netfs/read_helper.c +++ b/fs/netfs/read_helper.c @@ -933,7 +933,7 @@ cleanup: EXPORT_SYMBOL(netfs_readahead); /** - * netfs_page - Helper to manage a readpage request + * netfs_readpage - Helper to manage a readpage request * @file: The file to read from * @page: The page to read * @ops: The network filesystem's operations for the helper to use @@ -968,7 +968,7 @@ int netfs_readpage(struct file *file, return -ENOMEM; } rreq->mapping = page_file_mapping(page); - rreq->start = page_index(page) * PAGE_SIZE; + rreq->start = page_file_offset(page); rreq->len = thp_size(page); if (ops->begin_cache_operation) { @@ -1106,7 +1106,7 @@ retry: if (!rreq) goto error; rreq->mapping = page->mapping; - rreq->start = page->index * PAGE_SIZE; + rreq->start = page_offset(page); rreq->len = thp_size(page); rreq->no_unlock_page = page->index; __set_bit(NETFS_RREQ_NO_UNLOCK_PAGE, &rreq->flags);