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>

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 3c2d4ab..1d47d2e 100644 (file)
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -491,7 +491,7 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
                 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping)
                 * so shmem can relocate pages during swapin if required.
                 */
-               BUG_ON((mapping_gfp_mask(mapping) & __GFP_DMA32) &&
+               BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) &&
                                (page_to_pfn(p) >= 0x00100000UL));
        }
 

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7e505d4..399aab2 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2214,9 +2214,8 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
         * Fail silently without starting the shrinker
         */
        mapping = file_inode(obj->base.filp)->i_mapping;
-       gfp = mapping_gfp_mask(mapping);
+       gfp = mapping_gfp_constraint(mapping, ~(__GFP_IO | __GFP_RECLAIM));
        gfp |= __GFP_NORETRY | __GFP_NOWARN;
-       gfp &= ~(__GFP_IO | __GFP_RECLAIM);
        sg = st->sgl;
        st->nents = 0;
        for (i = 0; i < page_count; i++) {

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 57ee8ca..36dfeff 100644 (file)
--- 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 938efe3..eb90f0f 100644 (file)
--- 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 abe3a66..ed05da1 100644 (file)
--- 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 82283ab..51aff02 100644 (file)
--- 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 9d23e78..b7d218a 100644 (file)
--- 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 47c5c97..0068e82 100644 (file)
--- 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 612fbcf..60aaecd 100644 (file)
--- 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 560af04..1061611 100644 (file)
--- 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 7f9b096..6de0fbf 100644 (file)
--- 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 09abba7..1480d3a 100644 (file)
--- 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 0d3340b..3c18970 100644 (file)
--- 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 4a73d6d..ac2f649 100644 (file)
--- 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 262561f..9d383e5 100644 (file)
--- 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 5fc1e50..801c21c 100644 (file)
--- 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)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index a6c78e0..26eabf5 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -69,6 +69,13 @@ static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
        return (__force gfp_t)mapping->flags & __GFP_BITS_MASK;
 }
 
+/* Restricts the given gfp_mask to what the mapping allows. */
+static inline gfp_t mapping_gfp_constraint(struct address_space *mapping,
+               gfp_t gfp_mask)
+{
+       return mapping_gfp_mask(mapping) & gfp_mask;
+}
+
 /*
  * This is non-atomic.  Only to be used before the mapping is activated.
  * Probably needs a barrier...

diff --git a/mm/filemap.c b/mm/filemap.c
index 6ef3674..1bb0076 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1722,7 +1722,7 @@ no_cached_page:
                        goto out;
                }
                error = add_to_page_cache_lru(page, mapping, index,
-                                       GFP_KERNEL & mapping_gfp_mask(mapping));
+                               mapping_gfp_constraint(mapping, GFP_KERNEL));
                if (error) {
                        page_cache_release(page);
                        if (error == -EEXIST) {
@@ -1824,7 +1824,7 @@ static int page_cache_read(struct file *file, pgoff_t offset)
                        return -ENOMEM;
 
                ret = add_to_page_cache_lru(page, mapping, offset,
-                               GFP_KERNEL & mapping_gfp_mask(mapping));
+                               mapping_gfp_constraint(mapping, GFP_KERNEL));
                if (ret == 0)
                        ret = mapping->a_ops->readpage(file, page);
                else if (ret == -EEXIST)

diff --git a/mm/readahead.c b/mm/readahead.c
index 998ad59..ba22d7f 100644 (file)
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -90,7 +90,7 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
                page = list_to_page(pages);
                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))) {
                        read_cache_pages_invalidate_page(mapping, page);
                        continue;
                }
@@ -128,7 +128,7 @@ static int read_pages(struct address_space *mapping, struct file *filp,
                struct page *page = list_to_page(pages);
                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))) {
                        mapping->a_ops->readpage(filp, page);
                }
                page_cache_release(page);