[PATCH 02/18] btrfs: Carve out btrfs_get_extent_map_write() out of btrfs_get_blocks_write()

[Goldwyn Rodrigues]

From: Goldwyn Rodrigues <rgold...@suse.com>

This makes btrfs_get_extent_map_write() independent of Direct
I/O code.

Signed-off-by: Goldwyn Rodrigues <rgold...@suse.com>
---
 fs/btrfs/ctree.h |  2 ++
 fs/btrfs/inode.c | 40 +++++++++++++++++++++++++++-------------
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8ca1c0d120f4..9512f49262dd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3277,6 +3277,8 @@ struct inode *btrfs_iget_path(struct super_block *s, 
struct btrfs_key *location,
                              struct btrfs_path *path);
 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
                         struct btrfs_root *root, int *was_new);
+int btrfs_get_extent_map_write(struct extent_map **map, struct buffer_head *bh,
+               struct inode *inode, u64 start, u64 len);
 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
                                    struct page *page, size_t pg_offset,
                                    u64 start, u64 end, int create);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 82fdda8ff5ab..68b8a4935ba6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7496,11 +7496,10 @@ static int btrfs_get_blocks_direct_read(struct 
extent_map *em,
        return 0;
 }
 
-static int btrfs_get_blocks_direct_write(struct extent_map **map,
-                                        struct buffer_head *bh_result,
-                                        struct inode *inode,
-                                        struct btrfs_dio_data *dio_data,
-                                        u64 start, u64 len)
+int btrfs_get_extent_map_write(struct extent_map **map,
+               struct buffer_head *bh,
+               struct inode *inode,
+               u64 start, u64 len)
 {
        struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
        struct extent_map *em = *map;
@@ -7554,22 +7553,38 @@ static int btrfs_get_blocks_direct_write(struct 
extent_map **map,
                         */
                        btrfs_free_reserved_data_space_noquota(inode, start,
                                                               len);
-                       goto skip_cow;
+                       /* skip COW */
+                       goto out;
                }
        }
 
        /* this will cow the extent */
-       len = bh_result->b_size;
+       if (bh)
+               len = bh->b_size;
        free_extent_map(em);
        *map = em = btrfs_new_extent_direct(inode, start, len);
-       if (IS_ERR(em)) {
-               ret = PTR_ERR(em);
-               goto out;
-       }
+       if (IS_ERR(em))
+               return PTR_ERR(em);
+out:
+       return ret;
+}
 
+static int btrfs_get_blocks_direct_write(struct extent_map **map,
+                                        struct buffer_head *bh_result,
+                                        struct inode *inode,
+                                        struct btrfs_dio_data *dio_data,
+                                        u64 start, u64 len)
+{
+       int ret;
+       struct extent_map *em;
+
+       ret = btrfs_get_extent_map_write(map, bh_result, inode,
+                       start, len);
+       if (ret < 0)
+               return ret;
+       em = *map;
        len = min(len, em->len - (start - em->start));
 
-skip_cow:
        bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
                inode->i_blkbits;
        bh_result->b_size = len;
@@ -7590,7 +7605,6 @@ static int btrfs_get_blocks_direct_write(struct 
extent_map **map,
        dio_data->reserve -= len;
        dio_data->unsubmitted_oe_range_end = start + len;
        current->journal_info = dio_data;
-out:
        return ret;
 }
 
-- 
2.16.4

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