Btrfs: extent_map optimizations to cut down on CPU usage

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 10 insertions, 10 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index fd7e6c182b9d..16f0260fca66 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -644,20 +644,20 @@ int close_ctree(struct btrfs_root *root)
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf)
 {
-        struct inode *btree_inode = buf->last_page->mapping->host;
+        struct inode *btree_inode = buf->first_page->mapping->host;
         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
 }
 
 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
 {
-        struct inode *btree_inode = buf->last_page->mapping->host;
+        struct inode *btree_inode = buf->first_page->mapping->host;
         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
                                           buf);
 }
 
 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         u64 transid = btrfs_header_generation(buf);
         struct inode *btree_inode = root->fs_info->btree_inode;
 
@@ -678,7 +678,7 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
 
 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
@@ -686,7 +686,7 @@ void btrfs_set_buffer_defrag(struct extent_buffer *buf)
 
 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
@@ -695,7 +695,7 @@ void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
 
 int btrfs_buffer_defrag(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
@@ -703,7 +703,7 @@ int btrfs_buffer_defrag(struct extent_buffer *buf)
 
 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
                      buf->start, buf->start + buf->len - 1,
@@ -712,7 +712,7 @@ int btrfs_buffer_defrag_done(struct extent_buffer *buf)
 
 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
                      buf->start, buf->start + buf->len - 1,
@@ -721,7 +721,7 @@ int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
 
 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
                      buf->start, buf->start + buf->len - 1,
@@ -730,7 +730,7 @@ int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
 
 int btrfs_read_buffer(struct extent_buffer *buf)
 {
-        struct btrfs_root *root = BTRFS_I(buf->last_page->mapping->host)->root;
+        struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
         struct inode *btree_inode = root->fs_info->btree_inode;
         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
                                         buf, 1);