ocfs2: ocfs2_mv_xattr_buckets() can handle a partial cluster now.

If you look at ocfs2_mv_xattr_bucket_cross_cluster(), you'll notice that
two-thirds of the code is almost identical to ocfs2_mv_xattr_buckets().
The only difference is that ocfs2_mv_xattr_buckets() moves a whole
cluster's worth, while ocfs2_mv_xattr_bucket_cross_cluster() moves half
the cluster.

We change ocfs2_mv_xattr_buckets() to allow moving partial clusters.
The original caller of ocfs2_mv_xattr_buckets() still moves the whole
cluster's worth - it just passes a start_bucket of 0.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 20 insertions, 13 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index c1f2e0690747..97340940cee2 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -3995,18 +3995,19 @@ out:
 /*
  * src_blk points to the start of an existing extent.  last_blk points to
  * last cluster in that extent.  to_blk points to a newly allocated
- * extent.  We copy the buckets from cluster at last_blk to the new extent,
- * initializing its xh_num_buckets.  The old extent's xh_num_buckets
- * shrinks by the same amount.
+ * extent.  We copy the buckets from the cluster at last_blk to the new
+ * extent.  If start_bucket is non-zero, we skip that many buckets before
+ * we start copying.  The new extent's xh_num_buckets gets set to the
+ * number of buckets we copied.  The old extent's xh_num_buckets shrinks
+ * by the same amount.
  */
-static int ocfs2_mv_xattr_buckets(struct inode *inode,
-                                  handle_t *handle,
-                                  u64 src_blk, u64 last_blk,
-                                  u64 to_blk, u32 *first_hash)
+static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
+                                  u64 src_blk, u64 last_blk, u64 to_blk,
+                                  unsigned int start_bucket,
+                                  u32 *first_hash)
 {
         int i, ret, credits;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-        int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
         int blks_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
         int num_buckets = ocfs2_xattr_buckets_per_cluster(osb);
         struct ocfs2_xattr_bucket *old_first, *new_first;
@@ -4014,6 +4015,12 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode,
         mlog(0, "mv xattrs from cluster %llu to %llu\n",
              (unsigned long long)last_blk, (unsigned long long)to_blk);
 
+        BUG_ON(start_bucket >= num_buckets);
+        if (start_bucket) {
+                num_buckets -= start_bucket;
+                last_blk += (start_bucket * blks_per_bucket);
+        }
+
         /* The first bucket of the original extent */
         old_first = ocfs2_xattr_bucket_new(inode);
         /* The first bucket of the new extent */
@@ -4031,10 +4038,11 @@ static int ocfs2_mv_xattr_buckets(struct inode *inode,
         }
 
         /*
-         * We need to update the first bucket of the old extent and the
-         * entire first cluster of the new extent.
+         * We need to update the first bucket of the old extent and all
+         * the buckets going to the new extent.
          */
-        credits = blks_per_bucket + bpc + handle->h_buffer_credits;
+        credits = ((num_buckets + 1) * blks_per_bucket) +
+                handle->h_buffer_credits;
         ret = ocfs2_extend_trans(handle, credits);
         if (ret) {
                 mlog_errno(ret);
@@ -4177,8 +4185,7 @@ static int ocfs2_adjust_xattr_cross_cluster(struct inode *inode,
                 if (prev_clusters > 1 && (*header_bh)->b_blocknr != last_blk)
                         ret = ocfs2_mv_xattr_buckets(inode, handle,
                                                      (*first_bh)->b_blocknr,
-                                                     last_blk,
-                                                     new_blk,
+                                                     last_blk, new_blk, 0,
                                                      v_start);
                 else {
                         ret = ocfs2_divide_xattr_cluster(inode, handle,