On Thu, Jan 26, 2023 at 08:23:54PM +0000, Matthew Wilcox (Oracle) wrote:
> Saves a number of calls to compound_head().
Is this left over from an earlier version of this patch series? There
are no changes to calls to compound_head() that I can find in this
patch.
> @@ -565,10 +564,9 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
>
> /* We cannot recurse into the filesystem as the transaction is already
> * started */
> - flags = memalloc_nofs_save();
> - page = grab_cache_page_write_begin(mapping, 0);
> - memalloc_nofs_restore(flags);
> - if (!page) {
> + folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
> + mapping_gfp_mask(mapping));
> + if (!folio) {
> ret = -ENOMEM;
> goto out;
> }
Is there a reason why to use FGP_NOFS as opposed to using
memalloc_nofs_{save,restore}()?
I thought using memalloc_nofs_save() is considered the perferred
approach by mm-folks.
- Ted
