mm: allow GFP_{FS,IO} for page_cache_read page cache allocation

[linux-2.6-block.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 00bad7793788b2fb3342bda26335fc0713f0e909..ec9d4559514d6ac765f1e74d91c60ef04055c64f 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -51,6 +51,17 @@ extern int sysctl_legacy_va_layout;
 #define sysctl_legacy_va_layout 0
 #endif
 
+#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
+extern const int mmap_rnd_bits_min;
+extern const int mmap_rnd_bits_max;
+extern int mmap_rnd_bits __read_mostly;
+#endif
+#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
+extern const int mmap_rnd_compat_bits_min;
+extern const int mmap_rnd_compat_bits_max;
+extern int mmap_rnd_compat_bits __read_mostly;
+#endif
+
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -225,10 +236,14 @@ extern pgprot_t protection_map[16];
  * ->fault function. The vma's ->fault is responsible for returning a bitmask
  * of VM_FAULT_xxx flags that give details about how the fault was handled.
  *
+ * MM layer fills up gfp_mask for page allocations but fault handler might
+ * alter it if its implementation requires a different allocation context.
+ *
  * pgoff should be used in favour of virtual_address, if possible.
  */
 struct vm_fault {
        unsigned int flags;             /* FAULT_FLAG_xxx flags */
+       gfp_t gfp_mask;                 /* gfp mask to be used for allocations */
        pgoff_t pgoff;                  /* Logical page offset based on vma */
        void __user *virtual_address;   /* Faulting virtual address */
 
@@ -1361,10 +1376,26 @@ static inline void dec_mm_counter(struct mm_struct *mm, int member)
        atomic_long_dec(&mm->rss_stat.count[member]);
 }
 
+/* Optimized variant when page is already known not to be PageAnon */
+static inline int mm_counter_file(struct page *page)
+{
+       if (PageSwapBacked(page))
+               return MM_SHMEMPAGES;
+       return MM_FILEPAGES;
+}
+
+static inline int mm_counter(struct page *page)
+{
+       if (PageAnon(page))
+               return MM_ANONPAGES;
+       return mm_counter_file(page);
+}
+
 static inline unsigned long get_mm_rss(struct mm_struct *mm)
 {
        return get_mm_counter(mm, MM_FILEPAGES) +
-               get_mm_counter(mm, MM_ANONPAGES);
+               get_mm_counter(mm, MM_ANONPAGES) +
+               get_mm_counter(mm, MM_SHMEMPAGES);
 }
 
 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)