ocfs2: zero tail of sparse files on truncate

Since we don't zero on extend anymore, truncate needs to be fixed up to zero
the part of a file between i_size and and end of it's cluster. Otherwise a
subsequent extend could expose bad data.

This introduced a new helper, which can be used in ocfs2_write().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 29 insertions, 1 deletions

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 0bd86a137591..78c99b5050df 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -489,12 +489,38 @@ static int ocfs2_truncate_for_delete(struct ocfs2_super *osb,
         int status = 0;
         struct ocfs2_truncate_context *tc = NULL;
         struct ocfs2_dinode *fe;
+        handle_t *handle = NULL;
 
         mlog_entry_void();
 
         fe = (struct ocfs2_dinode *) fe_bh->b_data;
 
         if (fe->i_clusters) {
+                handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+                if (IS_ERR(handle)) {
+                        status = PTR_ERR(handle);
+                        mlog_errno(status);
+                        goto out;
+                }
+
+                status = ocfs2_journal_access(handle, inode, fe_bh,
+                                              OCFS2_JOURNAL_ACCESS_WRITE);
+                if (status < 0) {
+                        mlog_errno(status);
+                        goto out;
+                }
+
+                i_size_write(inode, 0);
+
+                status = ocfs2_mark_inode_dirty(handle, inode, fe_bh);
+                if (status < 0) {
+                        mlog_errno(status);
+                        goto out;
+                }
+
+                ocfs2_commit_trans(osb, handle);
+                handle = NULL;
+
                 status = ocfs2_prepare_truncate(osb, inode, fe_bh, &tc);
                 if (status < 0) {
                         mlog_errno(status);
@@ -507,8 +533,10 @@ static int ocfs2_truncate_for_delete(struct ocfs2_super *osb,
                         goto out;
                 }
         }
-out:
 
+out:
+        if (handle)
+                ocfs2_commit_trans(osb, handle);
         mlog_exit(status);
         return status;
 }