Btrfs: ensure an entire eb is written at once

This patch simplifies how we track our extent buffers.  Previously we could exit
writepages with only having written half of an extent buffer, which meant we had
to track the state of the pages and the state of the extent buffers differently.
Now we only read in entire extent buffers and write out entire extent buffers,
this allows us to simply set bits in our bflags to indicate the state of the eb
and we no longer have to do things like track uptodate with our iotree.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 11 insertions, 13 deletions

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 60628341f156..489d7945154f 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -37,6 +37,8 @@
 #define EXTENT_BUFFER_READAHEAD 4       /* this got triggered by readahead */
 #define EXTENT_BUFFER_TREE_REF 5
 #define EXTENT_BUFFER_STALE 6
+#define EXTENT_BUFFER_WRITEBACK 7
+#define EXTENT_BUFFER_IOERR 8
 
 /* these are flags for extent_clear_unlock_delalloc */
 #define EXTENT_CLEAR_UNLOCK_PAGE 0x1
@@ -99,6 +101,7 @@ struct extent_io_tree {
         struct radix_tree_root buffer;
         struct address_space *mapping;
         u64 dirty_bytes;
+        int track_uptodate;
         spinlock_t lock;
         spinlock_t buffer_lock;
         struct extent_io_ops *ops;
@@ -132,7 +135,7 @@ struct extent_buffer {
         struct extent_io_tree *tree;
         spinlock_t refs_lock;
         atomic_t refs;
-        atomic_t pages_reading;
+        atomic_t io_pages;
         struct list_head leak_list;
         struct rcu_head rcu_head;
         pid_t lock_owner;
@@ -249,6 +252,8 @@ int extent_writepages(struct extent_io_tree *tree,
                       struct address_space *mapping,
                       get_extent_t *get_extent,
                       struct writeback_control *wbc);
+int btree_write_cache_pages(struct address_space *mapping,
+                            struct writeback_control *wbc);
 int extent_readpages(struct extent_io_tree *tree,
                      struct address_space *mapping,
                      struct list_head *pages, unsigned nr_pages,
@@ -297,18 +302,11 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 void memset_extent_buffer(struct extent_buffer *eb, char c,
                           unsigned long start, unsigned long len);
 int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits);
-int clear_extent_buffer_dirty(struct extent_io_tree *tree,
-                              struct extent_buffer *eb);
-int set_extent_buffer_dirty(struct extent_io_tree *tree,
-                             struct extent_buffer *eb);
-int set_extent_buffer_uptodate(struct extent_io_tree *tree,
-                               struct extent_buffer *eb);
-int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
-                                struct extent_buffer *eb,
-                                struct extent_state **cached_state);
-int extent_buffer_uptodate(struct extent_io_tree *tree,
-                           struct extent_buffer *eb,
-                           struct extent_state *cached_state);
+int clear_extent_buffer_dirty(struct extent_buffer *eb);
+int set_extent_buffer_dirty(struct extent_buffer *eb);
+int set_extent_buffer_uptodate(struct extent_buffer *eb);
+int clear_extent_buffer_uptodate(struct extent_buffer *eb);
+int extent_buffer_uptodate(struct extent_buffer *eb);
 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
                       unsigned long min_len, char **map,
                       unsigned long *map_start,