Commit 31475dd6 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds

mm: a few small updates for radix-swap

Remove PageSwapBacked (!page_is_file_cache) cases from
add_to_page_cache_locked() and add_to_page_cache_lru(): those pages now
go through shmem_add_to_page_cache().

Remove a comment on maximum tmpfs size from fsstack_copy_inode_size(),
and add a comment on swap entries to invalidate_mapping_pages().

And mincore_page() uses find_get_page() on what might be shmem or a
tmpfs file: allow for a radix_tree_exceptional_entry(), and proceed to
find_get_page() on swapper_space if so (oh, swapper_space needs #ifdef).
Signed-off-by: default avatarHugh Dickins <>
Acked-by: default avatarRik van Riel <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 69f07ec9
......@@ -29,10 +29,7 @@ void fsstack_copy_inode_size(struct inode *dst, struct inode *src)
* We don't actually know what locking is used at the lower level;
* but if it's a filesystem that supports quotas, it will be using
* i_lock as in inode_add_bytes(). tmpfs uses other locking, and
* its 32-bit is (just) able to exceed 2TB i_size with the aid of
* holes; but its i_blocks cannot carry into the upper long without
* almost 2TB swap - let's ignore that case.
* i_lock as in inode_add_bytes().
if (sizeof(i_blocks) > sizeof(long))
......@@ -33,7 +33,6 @@
#include <linux/cpuset.h>
#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
#include <linux/memcontrol.h>
#include <linux/mm_inline.h> /* for page_is_file_cache() */
#include <linux/cleancache.h>
#include "internal.h"
......@@ -462,6 +461,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
int error;
error = mem_cgroup_cache_charge(page, current->mm,
gfp_mask & GFP_RECLAIM_MASK);
......@@ -479,8 +479,6 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
if (likely(!error)) {
__inc_zone_page_state(page, NR_FILE_PAGES);
if (PageSwapBacked(page))
__inc_zone_page_state(page, NR_SHMEM);
} else {
page->mapping = NULL;
......@@ -502,22 +500,9 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
int ret;
* Splice_read and readahead add shmem/tmpfs pages into the page cache
* before shmem_readpage has a chance to mark them as SwapBacked: they
* need to go on the anon lru below, and mem_cgroup_cache_charge
* (called in add_to_page_cache) needs to know where they're going too.
if (mapping_cap_swap_backed(mapping))
ret = add_to_page_cache(page, mapping, offset, gfp_mask);
if (ret == 0) {
if (page_is_file_cache(page))
if (ret == 0)
return ret;
......@@ -69,12 +69,14 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
* file will not get a swp_entry_t in its pte, but rather it is like
* any other file mapping (ie. marked !present and faulted in with
* tmpfs's .fault). So swapped out tmpfs mappings are tested here.
* However when tmpfs moves the page from pagecache and into swapcache,
* it is still in core, but the find_get_page below won't find it.
* No big deal, but make a note of it.
page = find_get_page(mapping, pgoff);
if (radix_tree_exceptional_entry(page)) {
swp_entry_t swap = radix_to_swp_entry(page);
page = find_get_page(&swapper_space, swap.val);
if (page) {
present = PageUptodate(page);
......@@ -336,6 +336,14 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
unsigned long count = 0;
int i;
* Note: this function may get called on a shmem/tmpfs mapping:
* pagevec_lookup() might then return 0 prematurely (because it
* got a gangful of swap entries); but it's hardly worth worrying
* about - it can rarely have anything to free from such a mapping
* (most pages are dirty), and already skips over any difficulties.
pagevec_init(&pvec, 0);
while (index <= end && pagevec_lookup(&pvec, mapping, index,
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
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