fs/ntfs3: Fix case when index is reused during tree transformation

In most cases when adding a cluster to the directory index,
they are placed at the end, and in the bitmap, this cluster corresponds
to the last bit. The new directory size is calculated as follows:

	data_size = (u64)(bit + 1) << indx->index_bits;

In the case of reusing a non-final cluster from the index,
data_size is calculated incorrectly, resulting in the directory size
differing from the actual size.

A check for cluster reuse has been added, and the size update is skipped.

Fixes: 82cae269cfa95 ("fs/ntfs3: Add initialization of super block")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: stable@vger.kernel.org

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index daabaad63aaf64ae65b8d67bbd40de837bfe3486..14284f0ed46aaa2dc5ce1d3c425e8eeaf08cb32c 100644 (file)
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -1533,6 +1533,11 @@ static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
                goto out1;
        }
 
+       if (data_size <= le64_to_cpu(alloc->nres.data_size)) {
+               /* Reuse index. */
+               goto out;
+       }
+
        /* Increase allocation. */
        err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
                            &indx->alloc_run, data_size, &data_size, true,
@@ -1546,6 +1551,7 @@ static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
        if (in->name == I30_NAME)
                i_size_write(&ni->vfs_inode, data_size);
 
+out:
        *vbn = bit << indx->idx2vbn_bits;
 
        return 0;