ext4: add EXT4_IOC_ALLOC_DA_BLKS ioctl

Add an ioctl which forces all of the delay allocated blocks to be
allocated.  This also provides a function ext4_alloc_da_blocks() which
will be used by the following commits to force files to be fully
allocated to preserve application-expected ext3 behaviour.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 14 insertions, 0 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 22dd29f3ebc9..91e75f7a9e73 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -262,6 +262,20 @@ setversion_out:
                 return err;
         }
 
+        case EXT4_IOC_ALLOC_DA_BLKS:
+        {
+                int err;
+                if (!is_owner_or_cap(inode))
+                        return -EACCES;
+
+                err = mnt_want_write(filp->f_path.mnt);
+                if (err)
+                        return err;
+                err = ext4_alloc_da_blocks(inode);
+                mnt_drop_write(filp->f_path.mnt);
+                return err;
+        }
+
         default:
                 return -ENOTTY;
         }