Merge tag 'spi-fix-v5.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni...

[linux-2.6-microblaze.git] / fs / btrfs / subpage.h

diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h
index 0120948..7accb5c 100644 (file)
--- a/fs/btrfs/subpage.h
+++ b/fs/btrfs/subpage.h
@@ -6,10 +6,38 @@
 #include <linux/spinlock.h>
 
 /*
- * Maximum page size we support is 64K, minimum sector size is 4K, u16 bitmap
- * is sufficient. Regular bitmap_* is not used due to size reasons.
+ * Extra info for subpapge bitmap.
+ *
+ * For subpage we pack all uptodate/error/dirty/writeback/ordered bitmaps into
+ * one larger bitmap.
+ *
+ * This structure records how they are organized in the bitmap:
+ *
+ * /- uptodate_offset  /- error_offset /- dirty_offset
+ * |                   |               |
+ * v                   v               v
+ * |u|u|u|u|........|u|u|e|e|.......|e|e| ...  |o|o|
+ * |<- bitmap_nr_bits ->|
+ * |<--------------- total_nr_bits ---------------->|
  */
-#define BTRFS_SUBPAGE_BITMAP_SIZE      16
+struct btrfs_subpage_info {
+       /* Number of bits for each bitmap */
+       unsigned int bitmap_nr_bits;
+
+       /* Total number of bits for the whole bitmap */
+       unsigned int total_nr_bits;
+
+       /*
+        * *_start indicates where the bitmap starts, the length is always
+        * @bitmap_size, which is calculated from PAGE_SIZE / sectorsize.
+        */
+       unsigned int uptodate_offset;
+       unsigned int error_offset;
+       unsigned int dirty_offset;
+       unsigned int writeback_offset;
+       unsigned int ordered_offset;
+       unsigned int checked_offset;
+};
 
 /*
  * Structure to trace status of each sector inside a page, attached to
@@ -18,10 +46,6 @@
 struct btrfs_subpage {
        /* Common members for both data and metadata pages */
        spinlock_t lock;
-       u16 uptodate_bitmap;
-       u16 error_bitmap;
-       u16 dirty_bitmap;
-       u16 writeback_bitmap;
        /*
         * Both data and metadata needs to track how many readers are for the
         * page.
@@ -38,14 +62,11 @@ struct btrfs_subpage {
                 * manages whether the subpage can be detached.
                 */
                atomic_t eb_refs;
-               /* Structures only used by data */
-               struct {
-                       atomic_t writers;
 
-                       /* Tracke pending ordered extent in this sector */
-                       u16 ordered_bitmap;
-               };
+               /* Structures only used by data */
+               atomic_t writers;
        };
+       unsigned long bitmaps[];
 };
 
 enum btrfs_subpage_type {
@@ -53,15 +74,15 @@ enum btrfs_subpage_type {
        BTRFS_SUBPAGE_DATA,
 };
 
+void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize);
 int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
                         struct page *page, enum btrfs_subpage_type type);
 void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info,
                          struct page *page);
 
 /* Allocate additional data where page represents more than one sector */
-int btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
-                       struct btrfs_subpage **ret,
-                       enum btrfs_subpage_type type);
+struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
+                                         enum btrfs_subpage_type type);
 void btrfs_free_subpage(struct btrfs_subpage *subpage);
 
 void btrfs_page_inc_eb_refs(const struct btrfs_fs_info *fs_info,
@@ -122,11 +143,14 @@ DECLARE_BTRFS_SUBPAGE_OPS(error);
 DECLARE_BTRFS_SUBPAGE_OPS(dirty);
 DECLARE_BTRFS_SUBPAGE_OPS(writeback);
 DECLARE_BTRFS_SUBPAGE_OPS(ordered);
+DECLARE_BTRFS_SUBPAGE_OPS(checked);
 
 bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,
                struct page *page, u64 start, u32 len);
 
 void btrfs_page_assert_not_dirty(const struct btrfs_fs_info *fs_info,
                                 struct page *page);
+void btrfs_page_unlock_writer(struct btrfs_fs_info *fs_info, struct page *page,
+                             u64 start, u32 len);
 
 #endif