On Tue 10-04-18 05:53:51, Matthew Wilcox wrote:
> From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
>
> The page cache has used the mapping's GFP flags for allocating
> radix tree nodes for a long time. It took care to always mask off the
> __GFP_HIGHMEM flag, and masked off other flags in other paths, but the
> __GFP_ZERO flag was still able to sneak through. The __GFP_DMA and
> __GFP_DMA32 flags would also have been able to sneak through if they
> were ever used. Fix them all by using GFP_RECLAIM_MASK at the innermost
> location, and remove it from earlier in the callchain.
>
> Fixes: 19f99cee206c ("f2fs: add core inode operations")
> Reported-by: Minchan Kim <minchan@xxxxxxxxxx>
> Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
I would push this into __radix_tree_preload...
Anyway
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> mm/filemap.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/mm/filemap.c b/mm/filemap.c
> index c2147682f4c3..1a4bfc5ed3dc 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -785,7 +785,7 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
> VM_BUG_ON_PAGE(!PageLocked(new), new);
> VM_BUG_ON_PAGE(new->mapping, new);
>
> - error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
> + error = radix_tree_preload(gfp_mask & GFP_RECLAIM_MASK);
> if (!error) {
> struct address_space *mapping = old->mapping;
> void (*freepage)(struct page *);
> @@ -841,7 +841,7 @@ static int __add_to_page_cache_locked(struct page *page,
> return error;
> }
>
> - error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM);
> + error = radix_tree_maybe_preload(gfp_mask & GFP_RECLAIM_MASK);
> if (error) {
> if (!huge)
> mem_cgroup_cancel_charge(page, memcg, false);
> @@ -1574,8 +1574,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
> if (fgp_flags & FGP_ACCESSED)
> __SetPageReferenced(page);
>
> - err = add_to_page_cache_lru(page, mapping, offset,
> - gfp_mask & GFP_RECLAIM_MASK);
> + err = add_to_page_cache_lru(page, mapping, offset, gfp_mask);
> if (unlikely(err)) {
> put_page(page);
> page = NULL;
> @@ -2378,7 +2377,7 @@ static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask)
> if (!page)
> return -ENOMEM;
>
> - ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask & GFP_KERNEL);
> + ret = add_to_page_cache_lru(page, mapping, offset, gfp_mask);
> if (ret == 0)
> ret = mapping->a_ops->readpage(file, page);
> else if (ret == -EEXIST)
> --
> 2.16.3
--
Michal Hocko
SUSE Labs
