Extract the common code from add_to_page_cache_locked so that
it could be shared by shmem file system.
Signed-off-by: Ning Qu <quning@xxxxxxxxx>
---
include/linux/pagemap.h | 2 ++
mm/filemap.c | 91 ++++++++++++++++++++++++++++++++-----------------
2 files changed, 61 insertions(+), 32 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8ce130f..1887255 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -548,6 +548,8 @@ static inline int fault_in_multipages_readable(const char __user *uaddr,
return ret;
}
+int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
+ pgoff_t index);
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
pgoff_t index, gfp_t gfp_mask);
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
diff --git a/mm/filemap.c b/mm/filemap.c
index 313df6d..998ee40 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -459,42 +459,22 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
EXPORT_SYMBOL_GPL(replace_page_cache_page);
/**
- * add_to_page_cache_locked - add a locked page to the pagecache
+ * __add_to_page_cache_locked - add a locked page to the pagecache
* @page: page to add
* @mapping: the page's address_space
* @offset: page index
- * @gfp_mask: page allocation mode
*
- * This function is used to add a page to the pagecache. It must be locked.
- * This function does not add the page to the LRU. The caller must do that.
+ * This function is the common code used for adding a page to the pagecache.
+ * mapping->tree_lock has to be held by caller.
*/
-int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
- pgoff_t offset, gfp_t gfp_mask)
+int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
+ pgoff_t offset)
{
- int error;
+ int error = 0;
int i, nr;
- VM_BUG_ON(!PageLocked(page));
- VM_BUG_ON(PageSwapBacked(page));
-
- /* memory cgroup controller handles thp pages on its side */
- error = mem_cgroup_cache_charge(page, current->mm,
- gfp_mask & GFP_RECLAIM_MASK);
- if (error)
- return error;
-
- if (PageTransHugeCache(page))
- BUILD_BUG_ON(HPAGE_CACHE_NR > RADIX_TREE_PRELOAD_NR);
-
nr = hpagecache_nr_pages(page);
- error = radix_tree_maybe_preload_contig(nr, gfp_mask & ~__GFP_HIGHMEM);
- if (error) {
- mem_cgroup_uncharge_cache_page(page);
- return error;
- }
-
- spin_lock_irq(&mapping->tree_lock);
page_cache_get(page);
page->index = offset;
page->mapping = mapping;
@@ -511,16 +491,14 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
goto err_insert;
}
}
- radix_tree_preload_end();
mapping->nrpages += nr;
__mod_zone_page_state(page_zone(page), NR_FILE_PAGES, nr);
if (PageTransHuge(page))
__inc_zone_page_state(page, NR_FILE_TRANSPARENT_HUGEPAGES);
- spin_unlock_irq(&mapping->tree_lock);
- trace_mm_filemap_add_to_page_cache(page);
+
return 0;
+
err_insert:
- radix_tree_preload_end();
if (i != 0)
error = -ENOSPC; /* no space for a huge page */
@@ -529,9 +507,58 @@ err_insert:
for (; i >= 0; i--)
radix_tree_delete(&mapping->page_tree, offset + i);
+ return error;
+}
+EXPORT_SYMBOL(__add_to_page_cache_locked);
+
+/**
+ * add_to_page_cache_locked - add a locked page to the pagecache
+ * @page: page to add
+ * @mapping: the page's address_space
+ * @offset: page index
+ * @gfp_mask: page allocation mode
+ *
+ * This function is used to add a page to the pagecache. It must be locked.
+ * This function does not add the page to the LRU. The caller must do that.
+ */
+int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
+ pgoff_t offset, gfp_t gfp_mask)
+{
+ int error;
+
+ VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON(PageSwapBacked(page));
+
+ /* memory cgroup controller handles thp pages on its side */
+ error = mem_cgroup_cache_charge(page, current->mm,
+ gfp_mask & GFP_RECLAIM_MASK);
+ if (error)
+ return error;
+
+ if (PageTransHugeCache(page))
+ BUILD_BUG_ON(HPAGE_CACHE_NR > RADIX_TREE_PRELOAD_NR);
+
+ error = radix_tree_maybe_preload_contig(hpagecache_nr_pages(page),
+ gfp_mask & ~__GFP_HIGHMEM);
+ if (error) {
+ mem_cgroup_uncharge_cache_page(page);
+ return error;
+ }
+
+ spin_lock_irq(&mapping->tree_lock);
+
+ error = __add_to_page_cache_locked(page, mapping, offset);
+
+ radix_tree_preload_end();
spin_unlock_irq(&mapping->tree_lock);
- mem_cgroup_uncharge_cache_page(page);
- page_cache_release(page);
+
+ if (!error)
+ trace_mm_filemap_add_to_page_cache(page);
+ else {
+ mem_cgroup_uncharge_cache_page(page);
+ page_cache_release(page);
+ }
+
return error;
}
EXPORT_SYMBOL(add_to_page_cache_locked);
--
1.8.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>