1 files changed, 12 insertions, 2 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3ca6943827ef..802a628e9f7d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3488,6 +3488,8 @@ static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
                         const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
 
                         len = round_down(i_size_read(src), sz) - loff;
+                        if (len == 0)
+                                return 0;
                         olen = len;
                 }
         }
@@ -4257,9 +4259,17 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
                 goto out_unlock;
         if (len == 0)
                 olen = len = src->i_size - off;
-        /* if we extend to eof, continue to block boundary */
-        if (off + len == src->i_size)
+        /*
+         * If we extend to eof, continue to block boundary if and only if the
+         * destination end offset matches the destination file's size, otherwise
+         * we would be corrupting data by placing the eof block into the middle
+         * of a file.
+         */
+        if (off + len == src->i_size) {
+                if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size)
+                        goto out_unlock;
                 len = ALIGN(src->i_size, bs) - off;
+        }
 
         if (len == 0) {
                 ret = 0;