On Mon, 2021-04-26 at 22:20 +0100, David Howells wrote: > Okay, how about the attached, then? > > David > --- > 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 <willy@xxxxxxxxxxxxx> > Signed-off-by: David Howells <dhowells@xxxxxxxxxx> > Link: https://lore.kernel.org/r/161789062190.6155.12711584466338493050.stgit@xxxxxxxxxxxxxxxxxxxxxx/ [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 @@ void netfs_readahead(struct readahead_control *ractl, > 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 @@ int netfs_write_begin(struct file *file, struct address_space *mapping, > 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); > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
