Btrfs: Update metadata reservation for delayed allocation

Introduce metadata reservation context for delayed allocation
and update various related functions.

This patch also introduces EXTENT_FIRST_DELALLOC control bit for
set/clear_extent_bit. It tells set/clear_bit_hook whether they
are processing the first extent_state with EXTENT_DELALLOC bit
set. This change is important if set/clear_extent_bit involves
multiple extent_state.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 10 insertions, 19 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3066da468c6d..6a706e691377 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -587,19 +587,9 @@ static int btrfs_defrag_file(struct file *file,
                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
                         BTRFS_I(inode)->force_compress = 1;
 
-                ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
-                if (ret) {
-                        ret = -ENOSPC;
-                        break;
-                }
-
-                ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
-                if (ret) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       PAGE_CACHE_SIZE);
-                        ret = -ENOSPC;
-                        break;
-                }
+                ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
+                if (ret)
+                        goto err_unlock;
 again:
                 if (inode->i_size == 0 ||
                     i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
@@ -608,8 +598,10 @@ again:
                 }
 
                 page = grab_cache_page(inode->i_mapping, i);
-                if (!page)
+                if (!page) {
+                        ret = -ENOMEM;
                         goto err_reservations;
+                }
 
                 if (!PageUptodate(page)) {
                         btrfs_readpage(NULL, page);
@@ -617,6 +609,7 @@ again:
                         if (!PageUptodate(page)) {
                                 unlock_page(page);
                                 page_cache_release(page);
+                                ret = -EIO;
                                 goto err_reservations;
                         }
                 }
@@ -630,8 +623,7 @@ again:
                 wait_on_page_writeback(page);
 
                 if (PageDirty(page)) {
-                        btrfs_free_reserved_data_space(root, inode,
-                                                       PAGE_CACHE_SIZE);
+                        btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
                         goto loop_unlock;
                 }
 
@@ -669,7 +661,6 @@ loop_unlock:
                 page_cache_release(page);
                 mutex_unlock(&inode->i_mutex);
 
-                btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
                 i++;
         }
@@ -699,9 +690,9 @@ loop_unlock:
         return 0;
 
 err_reservations:
+        btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
+err_unlock:
         mutex_unlock(&inode->i_mutex);
-        btrfs_free_reserved_data_space(root, inode, PAGE_CACHE_SIZE);
-        btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
         return ret;
 }