Merge branch 'samsung/fixes' of git+ssh://master.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / extent_io.h

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index a11a92ee2d30a84ccf52284e704c5cc971f7126e..7b2f0c3e79292a2f73aec86ed112e46b1a438c69 100644 (file)
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -76,15 +76,15 @@ struct extent_io_ops {
                                    struct extent_state *state);
        int (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
                                      struct extent_state *state, int uptodate);
-       int (*set_bit_hook)(struct inode *inode, struct extent_state *state,
-                           int *bits);
-       int (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
-                             int *bits);
-       int (*merge_extent_hook)(struct inode *inode,
-                                struct extent_state *new,
-                                struct extent_state *other);
-       int (*split_extent_hook)(struct inode *inode,
-                                struct extent_state *orig, u64 split);
+       void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
+                            int *bits);
+       void (*clear_bit_hook)(struct inode *inode, struct extent_state *state,
+                              int *bits);
+       void (*merge_extent_hook)(struct inode *inode,
+                                 struct extent_state *new,
+                                 struct extent_state *other);
+       void (*split_extent_hook)(struct inode *inode,
+                                 struct extent_state *orig, u64 split);
        int (*write_cache_pages_lock_hook)(struct page *page);
 };
 
@@ -108,8 +108,6 @@ struct extent_state {
        wait_queue_head_t wq;
        atomic_t refs;
        unsigned long state;
-       u64 split_start;
-       u64 split_end;
 
        /* for use by the FS */
        u64 private;
@@ -120,8 +118,6 @@ struct extent_state {
 struct extent_buffer {
        u64 start;
        unsigned long len;
-       char *map_token;
-       char *kaddr;
        unsigned long map_start;
        unsigned long map_len;
        struct page *first_page;
@@ -130,14 +126,26 @@ struct extent_buffer {
        struct rcu_head rcu_head;
        atomic_t refs;
 
-       /* the spinlock is used to protect most operations */
-       spinlock_t lock;
+       /* count of read lock holders on the extent buffer */
+       atomic_t write_locks;
+       atomic_t read_locks;
+       atomic_t blocking_writers;
+       atomic_t blocking_readers;
+       atomic_t spinning_readers;
+       atomic_t spinning_writers;
+
+       /* protects write locks */
+       rwlock_t lock;
 
-       /*
-        * when we keep the lock held while blocking, waiters go onto
-        * the wq
+       /* readers use lock_wq while they wait for the write
+        * lock holders to unlock
         */
-       wait_queue_head_t lock_wq;
+       wait_queue_head_t write_lock_wq;
+
+       /* writers use read_lock_wq while they wait for readers
+        * to unlock
+        */
+       wait_queue_head_t read_lock_wq;
 };
 
 static inline void extent_set_compress_type(unsigned long *bio_flags,
@@ -279,15 +287,10 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
 int extent_buffer_uptodate(struct extent_io_tree *tree,
                           struct extent_buffer *eb,
                           struct extent_state *cached_state);
-int map_extent_buffer(struct extent_buffer *eb, unsigned long offset,
-                     unsigned long min_len, char **token, char **map,
-                     unsigned long *map_start,
-                     unsigned long *map_len, int km);
 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
-                     unsigned long min_len, char **token, char **map,
+                     unsigned long min_len, char **map,
                      unsigned long *map_start,
-                     unsigned long *map_len, int km);
-void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km);
+                     unsigned long *map_len);
 int extent_range_uptodate(struct extent_io_tree *tree,
                          u64 start, u64 end);
 int extent_clear_unlock_delalloc(struct inode *inode,