ocfs2: Integrate CoW in file write.

When we use mmap, we CoW the refcountd clusters in
ocfs2_write_begin_nolock. While for normal file
io(including directio), we do CoW in
ocfs2_prepare_inode_for_write.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index fdad075fed61..9db9d64ca475 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -44,6 +44,7 @@
 #include "suballoc.h"
 #include "super.h"
 #include "symlink.h"
+#include "refcounttree.h"
 
 #include "buffer_head_io.h"
 
@@ -590,6 +591,8 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
                 goto bail;
         }
 
+        /* We should already CoW the refcounted extent. */
+        BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
         /*
          * get_more_blocks() expects us to describe a hole by clearing
          * the mapped bit on bh_result().
@@ -1449,6 +1452,9 @@ static int ocfs2_populate_write_desc(struct inode *inode,
                                 goto out;
                         }
 
+                        /* We should already CoW the refcountd extent. */
+                        BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
+
                         /*
                          * Assume worst case - that we're writing in
                          * the middle of the extent.
@@ -1700,6 +1706,19 @@ int ocfs2_write_begin_nolock(struct address_space *mapping,
                 goto out;
         }
 
+        ret = ocfs2_check_range_for_refcount(inode, pos, len);
+        if (ret < 0) {
+                mlog_errno(ret);
+                goto out;
+        } else if (ret == 1) {
+                ret = ocfs2_refcount_cow(inode, di_bh,
+                                         wc->w_cpos, wc->w_clen);
+                if (ret) {
+                        mlog_errno(ret);
+                        goto out;
+                }
+        }
+
         ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
                                         &extents_to_split);
         if (ret) {