ocfs2: CoW a reflinked cluster when it is truncated.
When we truncate a file to a specific size which resides in a reflinked
cluster, we need to CoW it since ocfs2_zero_range_for_truncate will
zero the space after the size(just another type of write).
So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when
it hit the max cluster offset.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 6ee20e8..75f5b81 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -335,6 +335,39 @@
return ret;
}
+static int ocfs2_cow_file_pos(struct inode *inode,
+ struct buffer_head *fe_bh,
+ u64 offset)
+{
+ int status;
+ u32 phys, cpos = offset >> OCFS2_SB(inode->i_sb)->s_clustersize_bits;
+ unsigned int num_clusters = 0;
+ unsigned int ext_flags = 0;
+
+ /*
+ * If the new offset is aligned to the range of the cluster, there is
+ * no space for ocfs2_zero_range_for_truncate to fill, so no need to
+ * CoW either.
+ */
+ if ((offset & (OCFS2_SB(inode->i_sb)->s_clustersize - 1)) == 0)
+ return 0;
+
+ status = ocfs2_get_clusters(inode, cpos, &phys,
+ &num_clusters, &ext_flags);
+ if (status) {
+ mlog_errno(status);
+ goto out;
+ }
+
+ if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
+ goto out;
+
+ return ocfs2_refcount_cow(inode, fe_bh, cpos, 1, cpos+1);
+
+out:
+ return status;
+}
+
static int ocfs2_orphan_for_truncate(struct ocfs2_super *osb,
struct inode *inode,
struct buffer_head *fe_bh,
@@ -347,6 +380,17 @@
mlog_entry_void();
+ /*
+ * We need to CoW the cluster contains the offset if it is reflinked
+ * since we will call ocfs2_zero_range_for_truncate later which will
+ * write "0" from offset to the end of the cluster.
+ */
+ status = ocfs2_cow_file_pos(inode, fe_bh, new_i_size);
+ if (status) {
+ mlog_errno(status);
+ return status;
+ }
+
/* TODO: This needs to actually orphan the inode in this
* transaction. */
@@ -1713,7 +1757,7 @@
*meta_level = 1;
- ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters);
+ ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
if (ret)
mlog_errno(ret);
out: