[PATCH] mm: clean up pagecache allocation

- Consolidate page_cache_alloc

- Fix splice: only the pagecache pages and filesystem data need to use
  mapping_gfp_mask.

- Fix grab_cache_page_nowait: same as splice, also honour NUMA placement.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 19 insertions, 28 deletions

diff --git a/fs/splice.c b/fs/splice.c
index 49fb9f129938..8d705954d294 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -74,7 +74,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
                 wait_on_page_writeback(page);
 
                 if (PagePrivate(page))
-                        try_to_release_page(page, mapping_gfp_mask(mapping));
+                        try_to_release_page(page, GFP_KERNEL);
 
                 /*
                  * If we succeeded in removing the mapping, set LRU flag
@@ -333,7 +333,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                                 break;
 
                         error = add_to_page_cache_lru(page, mapping, index,
-                                              mapping_gfp_mask(mapping));
+                                              GFP_KERNEL);
                         if (unlikely(error)) {
                                 page_cache_release(page);
                                 if (error == -EEXIST)
@@ -557,7 +557,6 @@ static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 {
         struct file *file = sd->file;
         struct address_space *mapping = file->f_mapping;
-        gfp_t gfp_mask = mapping_gfp_mask(mapping);
         unsigned int offset, this_len;
         struct page *page;
         pgoff_t index;
@@ -591,7 +590,7 @@ static int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
                         goto find_page;
 
                 page = buf->page;
-                if (add_to_page_cache(page, mapping, index, gfp_mask)) {
+                if (add_to_page_cache(page, mapping, index, GFP_KERNEL)) {
                         unlock_page(page);
                         goto find_page;
                 }
@@ -613,7 +612,7 @@ find_page:
                          * This will also lock the page
                          */
                         ret = add_to_page_cache_lru(page, mapping, index,
-                                                    gfp_mask);
+                                                    GFP_KERNEL);
                         if (unlikely(ret))
                                 goto out;
                 }
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 64f950925151..c3e255bf8594 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -52,19 +52,23 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
 void release_pages(struct page **pages, int nr, int cold);
 
 #ifdef CONFIG_NUMA
-extern struct page *page_cache_alloc(struct address_space *x);
-extern struct page *page_cache_alloc_cold(struct address_space *x);
+extern struct page *__page_cache_alloc(gfp_t gfp);
 #else
+static inline struct page *__page_cache_alloc(gfp_t gfp)
+{
+        return alloc_pages(gfp, 0);
+}
+#endif
+
 static inline struct page *page_cache_alloc(struct address_space *x)
 {
-        return alloc_pages(mapping_gfp_mask(x), 0);
+        return __page_cache_alloc(mapping_gfp_mask(x));
 }
 
 static inline struct page *page_cache_alloc_cold(struct address_space *x)
 {
-        return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
+        return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD);
 }
-#endif
 
 typedef int filler_t(void *, struct page *);
 
diff --git a/mm/filemap.c b/mm/filemap.c
index cb26e33fd0ff..7b84dc814347 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -467,25 +467,15 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 }
 
 #ifdef CONFIG_NUMA
-struct page *page_cache_alloc(struct address_space *x)
+struct page *__page_cache_alloc(gfp_t gfp)
 {
         if (cpuset_do_page_mem_spread()) {
                 int n = cpuset_mem_spread_node();
-                return alloc_pages_node(n, mapping_gfp_mask(x), 0);
+                return alloc_pages_node(n, gfp, 0);
         }
-        return alloc_pages(mapping_gfp_mask(x), 0);
+        return alloc_pages(gfp, 0);
 }
-EXPORT_SYMBOL(page_cache_alloc);
-
-struct page *page_cache_alloc_cold(struct address_space *x)
-{
-        if (cpuset_do_page_mem_spread()) {
-                int n = cpuset_mem_spread_node();
-                return alloc_pages_node(n, mapping_gfp_mask(x)|__GFP_COLD, 0);
-        }
-        return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
-}
-EXPORT_SYMBOL(page_cache_alloc_cold);
+EXPORT_SYMBOL(__page_cache_alloc);
 #endif
 
 static int __sleep_on_page_lock(void *word)
@@ -826,7 +816,6 @@ struct page *
 grab_cache_page_nowait(struct address_space *mapping, unsigned long index)
 {
         struct page *page = find_get_page(mapping, index);
-        gfp_t gfp_mask;
 
         if (page) {
                 if (!TestSetPageLocked(page))
@@ -834,9 +823,8 @@ grab_cache_page_nowait(struct address_space *mapping, unsigned long index)
                 page_cache_release(page);
                 return NULL;
         }
-        gfp_mask = mapping_gfp_mask(mapping) & ~__GFP_FS;
-        page = alloc_pages(gfp_mask, 0);
-        if (page && add_to_page_cache_lru(page, mapping, index, gfp_mask)) {
+        page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS);
+        if (page && add_to_page_cache_lru(page, mapping, index, GFP_KERNEL)) {
                 page_cache_release(page);
                 page = NULL;
         }