NTFS: Fix read regression.

The regression was caused by:
        commit[a32ea1e1f925399e0d81ca3f7394a44a6dafa12c] Fix read/truncate race

This causes ntfs_readpage() to be called for a zero i_size inode, which
failed when the file was compressed and non-resident.

Thanks a lot to Mike Galbraith for reporting the issue and tracking down
the commit that caused the regression.

Looking into it I found three bugs which the patch fixes.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Tested-by:  Mike Galbraith <efault@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 4 deletions

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 92dabdcf2b80..50d3b0c258e3 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -179,10 +179,7 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx)
          * ntfs_mapping_pairs_decompress() fails.
          */
         end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1;
-        if (!a->data.non_resident.lowest_vcn && end_vcn == 1)
-                end_vcn = sle64_to_cpu(a->data.non_resident.allocated_size) >>
-                                ni->vol->cluster_size_bits;
-        if (unlikely(vcn >= end_vcn)) {
+        if (unlikely(vcn && vcn >= end_vcn)) {
                 err = -ENOENT;
                 goto err_out;
         }