1 files changed, 25 insertions, 6 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index b8a7637e14a1..1a0510ad030c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -364,6 +364,7 @@ int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans,
                        u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
 {
         u64 extent_end = 0;
+        u64 locked_end = end;
         u64 search_start = start;
         u64 leaf_start;
         u64 ram_bytes = 0;
@@ -479,12 +480,6 @@ next_slot:
                         goto next_slot;
                 }
 
-                if (found_inline) {
-                        u64 mask = root->sectorsize - 1;
-                        search_start = (extent_end + mask) & ~mask;
-                } else
-                        search_start = extent_end;
-
                 if (end <= extent_end && start >= key.offset && found_inline)
                         *hint_byte = EXTENT_MAP_INLINE;
 
@@ -501,6 +496,26 @@ next_slot:
                         if (found_inline && start <= key.offset)
                                 keep = 1;
                 }
+
+                if (bookend && found_extent && locked_end < extent_end) {
+                        ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
+                                        locked_end, extent_end - 1, GFP_NOFS);
+                        if (!ret) {
+                                btrfs_release_path(root, path);
+                                lock_extent(&BTRFS_I(inode)->io_tree,
+                                        locked_end, extent_end - 1, GFP_NOFS);
+                                locked_end = extent_end;
+                                continue;
+                        }
+                        locked_end = extent_end;
+                }
+
+                if (found_inline) {
+                        u64 mask = root->sectorsize - 1;
+                        search_start = (extent_end + mask) & ~mask;
+                } else
+                        search_start = extent_end;
+
                 /* truncate existing extent */
                 if (start > key.offset) {
                         u64 new_num;
@@ -638,6 +653,10 @@ next_slot:
         }
 out:
         btrfs_free_path(path);
+        if (locked_end > end) {
+                unlock_extent(&BTRFS_I(inode)->io_tree, end, locked_end - 1,
+                              GFP_NOFS);
+        }
         btrfs_check_file(root, inode);
         return ret;
 }