2 files changed, 50 insertions, 18 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 876cddd6b2f0..248d20265249 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1334,7 +1334,6 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb,
                                     loff_t *ppos, size_t count, size_t ocount)
 {
         struct file *file = iocb->ki_filp;
-        struct inode *inode = fdentry(file)->d_inode;
         struct iov_iter i;
         ssize_t written;
         ssize_t written_buffered;
@@ -1344,18 +1343,6 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb,
         written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
                                             count, ocount);
 
-        /*
-         * the generic O_DIRECT will update in-memory i_size after the
-         * DIOs are done.  But our endio handlers that update the on
-         * disk i_size never update past the in memory i_size.  So we
-         * need one more update here to catch any additions to the
-         * file
-         */
-        if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
-                btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
-                mark_inode_dirty(inode);
-        }
-
         if (written < 0 || written == count)
                 return written;
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4a4f2d59a64b..6971fb5fc859 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5904,8 +5904,17 @@ map:
         bh_result->b_size = len;
         bh_result->b_bdev = em->bdev;
         set_buffer_mapped(bh_result);
-        if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
-                set_buffer_new(bh_result);
+        if (create) {
+                if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+                        set_buffer_new(bh_result);
+
+                /*
+                 * Need to update the i_size under the extent lock so buffered
+                 * readers will get the updated i_size when we unlock.
+                 */
+                if (start + len > i_size_read(inode))
+                        i_size_write(inode, start + len);
+        }
 
         free_extent_map(em);
 
@@ -6388,12 +6397,48 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
                  */
                 ordered = btrfs_lookup_ordered_range(inode, lockstart,
                                                      lockend - lockstart + 1);
-                if (!ordered)
+
+                /*
+                 * We need to make sure there are no buffered pages in this
+                 * range either, we could have raced between the invalidate in
+                 * generic_file_direct_write and locking the extent.  The
+                 * invalidate needs to happen so that reads after a write do not
+                 * get stale data.
+                 */
+                if (!ordered && (!writing ||
+                    !test_range_bit(&BTRFS_I(inode)->io_tree,
+                                    lockstart, lockend, EXTENT_UPTODATE, 0,
+                                    cached_state)))
                         break;
+
                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
                                      &cached_state, GFP_NOFS);
-                btrfs_start_ordered_extent(inode, ordered, 1);
-                btrfs_put_ordered_extent(ordered);
+
+                if (ordered) {
+                        btrfs_start_ordered_extent(inode, ordered, 1);
+                        btrfs_put_ordered_extent(ordered);
+                } else {
+                        /* Screw you mmap */
+                        ret = filemap_write_and_wait_range(file->f_mapping,
+                                                           lockstart,
+                                                           lockend);
+                        if (ret)
+                                goto out;
+
+                        /*
+                         * If we found a page that couldn't be invalidated just
+                         * fall back to buffered.
+                         */
+                        ret = invalidate_inode_pages2_range(file->f_mapping,
+                                        lockstart >> PAGE_CACHE_SHIFT,
+                                        lockend >> PAGE_CACHE_SHIFT);
+                        if (ret) {
+                                if (ret == -EBUSY)
+                                        ret = 0;
+                                goto out;
+                        }
+                }
+
                 cond_resched();
         }