ext4: don't bump up LONG_MAX nr_to_write by a factor of 8

I'm uneasy with lots of stuff going on in ext4_da_writepages(),
but bumping nr_to_write from LLONG_MAX to -8 clearly isn't
making anything better, so avoid the multiplier in that case.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 6 insertions, 3 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d88ba4a9effa..50f3bba68a25 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3004,9 +3004,12 @@ static int ext4_da_writepages(struct address_space *mapping,
          * sbi->max_writeback_mb_bump whichever is smaller.
          */
         max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
-        if (!range_cyclic && range_whole)
-                desired_nr_to_write = wbc->nr_to_write * 8;
-        else
+        if (!range_cyclic && range_whole) {
+                if (wbc->nr_to_write == LONG_MAX)
+                        desired_nr_to_write = wbc->nr_to_write;
+                else
+                        desired_nr_to_write = wbc->nr_to_write * 8;
+        } else
                 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
                                                            max_pages);
         if (desired_nr_to_write > max_pages)