1 files changed, 7 insertions, 3 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 20452c110d7d..841cfe3be0e0 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2242,6 +2242,7 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int origin)
         if (lockend <= lockstart)
                 lockend = lockstart + root->sectorsize;
 
+        lockend--;
         len = lockend - lockstart + 1;
 
         len = max_t(u64, len, root->sectorsize);
@@ -2308,9 +2309,12 @@ static int find_desired_extent(struct inode *inode, loff_t *offset, int origin)
                                         }
                                 }
 
-                                *offset = start;
-                                free_extent_map(em);
-                                break;
+                                if (!test_bit(EXTENT_FLAG_PREALLOC,
+                                              &em->flags)) {
+                                        *offset = start;
+                                        free_extent_map(em);
+                                        break;
+                                }
                         }
                 }