1 files changed, 50 insertions, 34 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index f28a1b3e63a9..ff0b8844bd5a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -168,12 +168,7 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
 #define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
 
-#define VM_CAN_INVALIDATE 0x08000000    /* The mapping may be invalidated,
-                                         * eg. truncate or invalidate_inode_*.
-                                         * In this case, do_no_page must
-                                         * return with the page locked.
-                                         */
-#define VM_CAN_NONLINEAR 0x10000000     /* Has ->fault & does nonlinear pages */
+#define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
 
 #ifndef VM_STACK_DEFAULT_FLAGS          /* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
@@ -197,24 +192,44 @@ extern unsigned int kobjsize(const void *objp);
  */
 extern pgprot_t protection_map[16];
 
-#define FAULT_FLAG_WRITE        0x01
-#define FAULT_FLAG_NONLINEAR    0x02
+#define FAULT_FLAG_WRITE        0x01    /* Fault was a write access */
+#define FAULT_FLAG_NONLINEAR    0x02    /* Fault was via a nonlinear mapping */
+
+
+#define FAULT_RET_NOPAGE        0x0100  /* ->fault did not return a page. This
+                                         * can be used if the handler installs
+                                         * their own pte.
+                                         */
+#define FAULT_RET_LOCKED        0x0200  /* ->fault locked the page, caller must
+                                         * unlock after installing the mapping.
+                                         * This is used by pagecache in
+                                         * particular, where the page lock is
+                                         * used to synchronise against truncate
+                                         * and invalidate. Mutually exclusive
+                                         * with FAULT_RET_NOPAGE.
+                                         */
 
 /*
- * fault_data is filled in the the pagefault handler and passed to the
- * vma's ->fault function. That function is responsible for filling in
- * 'type', which is the type of fault if a page is returned, or the type
- * of error if NULL is returned.
+ * vm_fault is filled by the the pagefault handler and passed to the vma's
+ * ->fault function. The vma's ->fault is responsible for returning the
+ * VM_FAULT_xxx type which occupies the lowest byte of the return code, ORed
+ * with FAULT_RET_ flags that occupy the next byte and give details about
+ * how the fault was handled.
  *
- * pgoff should be used in favour of address, if possible. If pgoff is
- * used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get
- * nonlinear mapping support.
+ * pgoff should be used in favour of virtual_address, if possible. If pgoff
+ * is used, one may set VM_CAN_NONLINEAR in the vma->vm_flags to get nonlinear
+ * mapping support.
  */
-struct fault_data {
-        unsigned long address;
-        pgoff_t pgoff;
-        unsigned int flags;
-        int type;
+struct vm_fault {
+        unsigned int flags;             /* FAULT_FLAG_xxx flags */
+        pgoff_t pgoff;                  /* Logical page offset based on vma */
+        void __user *virtual_address;   /* Faulting virtual address */
+
+        struct page *page;              /* ->fault handlers should return a
+                                         * page here, unless FAULT_RET_NOPAGE
+                                         * is set (which is also implied by
+                                         * VM_FAULT_OOM or SIGBUS).
+                                         */
 };
 
 /*
@@ -225,15 +240,11 @@ struct fault_data {
 struct vm_operations_struct {
         void (*open)(struct vm_area_struct * area);
         void (*close)(struct vm_area_struct * area);
-        struct page *(*fault)(struct vm_area_struct *vma,
-                        struct fault_data *fdata);
+        int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
         struct page *(*nopage)(struct vm_area_struct *area,
                         unsigned long address, int *type);
         unsigned long (*nopfn)(struct vm_area_struct *area,
                         unsigned long address);
-        int (*populate)(struct vm_area_struct *area, unsigned long address,
-                        unsigned long len, pgprot_t prot, unsigned long pgoff,
-                        int nonblock);
 
         /* notification that a previously read-only page is about to become
          * writable, if an error is returned it will cause a SIGBUS */
@@ -700,8 +711,14 @@ static inline int page_mapped(struct page *page)
  * Used to decide whether a process gets delivered SIGBUS or
  * just gets major/minor fault counters bumped up.
  */
-#define VM_FAULT_OOM    0x00
-#define VM_FAULT_SIGBUS 0x01
+
+/*
+ * VM_FAULT_ERROR is set for the error cases, to make some tests simpler.
+ */
+#define VM_FAULT_ERROR  0x20
+
+#define VM_FAULT_OOM    (0x00 | VM_FAULT_ERROR)
+#define VM_FAULT_SIGBUS (0x01 | VM_FAULT_ERROR)
 #define VM_FAULT_MINOR  0x02
 #define VM_FAULT_MAJOR  0x03
 
@@ -711,6 +728,11 @@ static inline int page_mapped(struct page *page)
  */
 #define VM_FAULT_WRITE  0x10
 
+/*
+ * Mask of VM_FAULT_ flags
+ */
+#define VM_FAULT_MASK   0xff
+
 #define offset_in_page(p)       ((unsigned long)(p) & ~PAGE_MASK)
 
 extern void show_free_areas(void);
@@ -793,8 +815,6 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping,
 
 extern int vmtruncate(struct inode * inode, loff_t offset);
 extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end);
-extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
-extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
 
 #ifdef CONFIG_MMU
 extern int __handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma,
@@ -1135,11 +1155,7 @@ extern void truncate_inode_pages_range(struct address_space *,
                                        loff_t lstart, loff_t lend);
 
 /* generic vm_area_ops exported for stackable file systems */
-extern struct page *filemap_fault(struct vm_area_struct *, struct fault_data *);
-extern struct page * __deprecated_for_modules
-filemap_nopage(struct vm_area_struct *, unsigned long, int *);
-extern int __deprecated_for_modules filemap_populate(struct vm_area_struct *,
-                unsigned long, unsigned long, pgprot_t, unsigned long, int);
+extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
 
 /* mm/page-writeback.c */
 int write_one_page(struct page *page, int wait);