NTFS: Fix a stupid bug causing writes to non-initialized pages to segfault.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>

1 files changed, 9 insertions, 8 deletions

diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index cf3e6ced2d01..727533891813 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -668,10 +668,10 @@ map_buffer_cached:
                                  * to, we need to read it in before the write,
                                  * i.e. now.
                                  */
-                                if (!buffer_uptodate(bh) && ((bh_pos < pos &&
-                                                bh_end > pos) ||
-                                                (bh_end > end &&
-                                                bh_end > end))) {
+                                if (!buffer_uptodate(bh) && bh_pos < end &&
+                                                bh_end > pos &&
+                                                (bh_pos < pos ||
+                                                bh_end > end)) {
                                         /*
                                          * If the buffer is fully or partially
                                          * within the initialized size, do an
@@ -784,10 +784,11 @@ retry_remap:
                                                 blocksize_bits);
                                 cdelta = 0;
                                 /*
-                                 * If the number of remaining clusters in the
-                                 * @pages is smaller or equal to the number of
-                                 * cached clusters, unlock the runlist as the
-                                 * map cache will be used from now on.
+                                 * If the number of remaining clusters touched
+                                 * by the write is smaller or equal to the
+                                 * number of cached clusters, unlock the
+                                 * runlist as the map cache will be used from
+                                 * now on.
                                  */
                                 if (likely(vcn + vcn_len >= cend)) {
                                         if (rl_write_locked) {