1 files changed, 31 insertions, 5 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fba7a004e7e5..362720a3fea2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3410,15 +3410,41 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
                         goto out_unlock;
         }
 
-        /* truncate page cache pages from target inode range */
-        truncate_inode_pages_range(&inode->i_data, destoff,
-                                   PAGE_CACHE_ALIGN(destoff + len) - 1);
+        /*
+         * Lock the target range too. Right after we replace the file extent
+         * items in the fs tree (which now point to the cloned data), we might
+         * have a worker replace them with extent items relative to a write
+         * operation that was issued before this clone operation (i.e. confront
+         * with inode.c:btrfs_finish_ordered_io).
+         */
+        if (same_inode) {
+                u64 lock_start = min_t(u64, off, destoff);
+                u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
 
-        lock_extent_range(src, off, len);
+                lock_extent_range(src, lock_start, lock_len);
+        } else {
+                lock_extent_range(src, off, len);
+                lock_extent_range(inode, destoff, len);
+        }
 
         ret = btrfs_clone(src, inode, off, olen, len, destoff);
 
-        unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
+        if (same_inode) {
+                u64 lock_start = min_t(u64, off, destoff);
+                u64 lock_end = max_t(u64, off, destoff) + len - 1;
+
+                unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
+        } else {
+                unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
+                unlock_extent(&BTRFS_I(inode)->io_tree, destoff,
+                              destoff + len - 1);
+        }
+        /*
+         * Truncate page cache pages so that future reads will see the cloned
+         * data immediately and not the previous data.
+         */
+        truncate_inode_pages_range(&inode->i_data, destoff,
+                                   PAGE_CACHE_ALIGN(destoff + len) - 1);
 out_unlock:
         if (!same_inode) {
                 if (inode < src) {