mm, fs: introduce mapping_gfp_constraint()

There are many places which use mapping_gfp_mask to restrict a more
generic gfp mask which would be used for allocations which are not
directly related to the page cache but they are performed in the same
context.

Let's introduce a helper function which makes the restriction explicit and
easier to track.  This patch doesn't introduce any functional changes.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

14 files changed, 23 insertions, 23 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 57ee8ca29b06..36dfeff2c1f4 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -482,13 +482,12 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 			goto next;
 		}
 
-		page = __page_cache_alloc(mapping_gfp_mask(mapping) &
-								~__GFP_FS);
+		page = __page_cache_alloc(mapping_gfp_constraint(mapping,
+								 ~__GFP_FS));
 		if (!page)
 			break;
 
-		if (add_to_page_cache_lru(page, mapping, pg_index,
-								GFP_NOFS)) {
+		if (add_to_page_cache_lru(page, mapping, pg_index, GFP_NOFS)) {
 			page_cache_release(page);
 			goto next;
 		}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 938efe33be80..eb90f0f1a124 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3316,7 +3316,7 @@ static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
 
 static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
 {
-	return mapping_gfp_mask(mapping) & ~__GFP_FS;
+	return mapping_gfp_constraint(mapping, ~__GFP_FS);
 }
 
 /* extent-tree.c */
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index abe3a66bd3ba..ed05da1b977e 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -85,8 +85,8 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 	}
 
 	mapping_set_gfp_mask(inode->i_mapping,
-			mapping_gfp_mask(inode->i_mapping) &
-			~(__GFP_FS | __GFP_HIGHMEM));
+			mapping_gfp_constraint(inode->i_mapping,
+			~(__GFP_FS | __GFP_HIGHMEM)));
 
 	return inode;
 }
diff --git a/fs/buffer.c b/fs/buffer.c
index 82283abb2795..51aff0296ce2 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -999,7 +999,7 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 	int ret = 0;		/* Will call free_more_memory() */
 	gfp_t gfp_mask;
 
-	gfp_mask = (mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS) | gfp;
+	gfp_mask = mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS) | gfp;
 
 	/*
 	 * XXX: __getblk_slow() can not really deal with failure and
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 9d23e788d1df..b7d218a168fb 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1283,8 +1283,8 @@ static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		int ret1;
 		struct address_space *mapping = inode->i_mapping;
 		struct page *page = find_or_create_page(mapping, 0,
-						mapping_gfp_mask(mapping) &
-						~__GFP_FS);
+						mapping_gfp_constraint(mapping,
+						~__GFP_FS));
 		if (!page) {
 			ret = VM_FAULT_OOM;
 			goto out;
@@ -1428,7 +1428,8 @@ void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
 		if (i_size_read(inode) == 0)
 			return;
 		page = find_or_create_page(mapping, 0,
-					   mapping_gfp_mask(mapping) & ~__GFP_FS);
+					   mapping_gfp_constraint(mapping,
+					   ~__GFP_FS));
 		if (!page)
 			return;
 		if (PageUptodate(page)) {
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 47c5c97e2dd3..0068e82217c3 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3380,7 +3380,7 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 	struct page *page, *tpage;
 	unsigned int expected_index;
 	int rc;
-	gfp_t gfp = GFP_KERNEL & mapping_gfp_mask(mapping);
+	gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
 
 	INIT_LIST_HEAD(tmplist);
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 612fbcf76b5c..60aaecd5598b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3344,7 +3344,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 	int err = 0;
 
 	page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
-				   mapping_gfp_mask(mapping) & ~__GFP_FS);
+				   mapping_gfp_constraint(mapping, ~__GFP_FS));
 	if (!page)
 		return -ENOMEM;
 
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 560af0437704..1061611ae14d 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -166,7 +166,7 @@ int ext4_mpage_readpages(struct address_space *mapping,
 			page = list_entry(pages->prev, struct page, lru);
 			list_del(&page->lru);
 			if (add_to_page_cache_lru(page, mapping, page->index,
-					GFP_KERNEL & mapping_gfp_mask(mapping)))
+				  mapping_gfp_constraint(mapping, GFP_KERNEL)))
 				goto next_page;
 		}
 
diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
index 7f9b096d8d57..6de0fbfc6c00 100644
--- a/fs/logfs/segment.c
+++ b/fs/logfs/segment.c
@@ -57,7 +57,7 @@ static struct page *get_mapping_page(struct super_block *sb, pgoff_t index,
 	filler_t *filler = super->s_devops->readpage;
 	struct page *page;
 
-	BUG_ON(mapping_gfp_mask(mapping) & __GFP_FS);
+	BUG_ON(mapping_gfp_constraint(mapping, __GFP_FS));
 	if (use_filler)
 		page = read_cache_page(mapping, index, filler, sb);
 	else {
diff --git a/fs/mpage.c b/fs/mpage.c
index 09abba7653aa..1480d3a18037 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -361,7 +361,7 @@ mpage_readpages(struct address_space *mapping, struct list_head *pages,
 	sector_t last_block_in_bio = 0;
 	struct buffer_head map_bh;
 	unsigned long first_logical_block = 0;
-	gfp_t gfp = GFP_KERNEL & mapping_gfp_mask(mapping);
+	gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
 
 	map_bh.b_state = 0;
 	map_bh.b_size = 0;
@@ -397,7 +397,7 @@ int mpage_readpage(struct page *page, get_block_t get_block)
 	sector_t last_block_in_bio = 0;
 	struct buffer_head map_bh;
 	unsigned long first_logical_block = 0;
-	gfp_t gfp = GFP_KERNEL & mapping_gfp_mask(page->mapping);
+	gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
 
 	map_bh.b_state = 0;
 	map_bh.b_size = 0;
diff --git a/fs/namei.c b/fs/namei.c
index 0d3340b32e14..3c18970a8899 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4604,7 +4604,7 @@ EXPORT_SYMBOL(__page_symlink);
 int page_symlink(struct inode *inode, const char *symname, int len)
 {
 	return __page_symlink(inode, symname, len,
-			!(mapping_gfp_mask(inode->i_mapping) & __GFP_FS));
+			!mapping_gfp_constraint(inode->i_mapping, __GFP_FS));
 }
 EXPORT_SYMBOL(page_symlink);
 
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 4a73d6dffabf..ac2f64943ff4 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -356,7 +356,7 @@ struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 		goto failed;
 
 	mapping_set_gfp_mask(inode->i_mapping,
-			     mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
+			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 
 	root = NILFS_I(dir)->i_root;
 	ii = NILFS_I(inode);
@@ -522,7 +522,7 @@ static int __nilfs_read_inode(struct super_block *sb,
 	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 	nilfs_set_inode_flags(inode);
 	mapping_set_gfp_mask(inode->i_mapping,
-			     mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
+			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 	return 0;
 
  failed_unmap:
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 262561fea923..9d383e5eff0e 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -525,8 +525,8 @@ static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
 				}
 			}
 			err = add_to_page_cache_lru(*cached_page, mapping,
-					index,
-					GFP_KERNEL & mapping_gfp_mask(mapping));
+				   index,
+				   mapping_gfp_constraint(mapping, GFP_KERNEL));
 			if (unlikely(err)) {
 				if (err == -EEXIST)
 					continue;
diff --git a/fs/splice.c b/fs/splice.c
index 5fc1e50a7f30..801c21cd77fe 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -360,7 +360,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 				break;
 
 			error = add_to_page_cache_lru(page, mapping, index,
-					GFP_KERNEL & mapping_gfp_mask(mapping));
+				   mapping_gfp_constraint(mapping, GFP_KERNEL));
 			if (unlikely(error)) {
 				page_cache_release(page);
 				if (error == -EEXIST)