summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/linux/shmem_fs.h17
-rw-r--r--mm/shmem.c23
2 files changed, 33 insertions, 7 deletions
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 22a20af4d785..aa08fa8fd79b 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -3,15 +3,9 @@
#include <linux/swap.h>
#include <linux/mempolicy.h>
+#include <linux/pagemap.h>
#include <linux/percpu_counter.h>
-struct page;
-struct file;
-struct inode;
-struct super_block;
-struct user_struct;
-struct vm_area_struct;
-
/* inode in-kernel data */
#define SHMEM_NR_DIRECT 16
@@ -61,9 +55,18 @@ extern struct file *shmem_file_setup(const char *name,
loff_t size, unsigned long flags);
extern int shmem_zero_setup(struct vm_area_struct *);
extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
+extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
+ pgoff_t index, gfp_t gfp_mask);
extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
extern int shmem_unuse(swp_entry_t entry, struct page *page);
extern void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
struct page **pagep, swp_entry_t *ent);
+static inline struct page *shmem_read_mapping_page(
+ struct address_space *mapping, pgoff_t index)
+{
+ return shmem_read_mapping_page_gfp(mapping, index,
+ mapping_gfp_mask(mapping));
+}
+
#endif
diff --git a/mm/shmem.c b/mm/shmem.c
index f1714758ea96..fcedf5464eb7 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3035,3 +3035,26 @@ int shmem_zero_setup(struct vm_area_struct *vma)
vma->vm_flags |= VM_CAN_NONLINEAR;
return 0;
}
+
+/**
+ * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags.
+ * @mapping: the page's address_space
+ * @index: the page index
+ * @gfp: the page allocator flags to use if allocating
+ *
+ * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)",
+ * with any new page allocations done using the specified allocation flags.
+ * But read_cache_page_gfp() uses the ->readpage() method: which does not
+ * suit tmpfs, since it may have pages in swapcache, and needs to find those
+ * for itself; although drivers/gpu/drm i915 and ttm rely upon this support.
+ *
+ * Provide a stub for those callers to start using now, then later
+ * flesh it out to call shmem_getpage() with additional gfp mask, when
+ * shmem_file_splice_read() is added and shmem_readpage() is removed.
+ */
+struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
+ pgoff_t index, gfp_t gfp)
+{
+ return read_cache_page_gfp(mapping, index, gfp);
+}
+EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp);