Merge tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "A fix of a corruption regarding fsync and clone, under some very
  specific conditions explained in the patch.

  The fix is marked for stable 3.16+ so I'd like to get it merged now
  given the impact"

* tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix file data corruption after cloning a range and fsync

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e55843f536bc..b3e45714d28f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4238,8 +4238,9 @@ int try_release_extent_mapping(struct page *page, gfp_t mask)
         struct extent_map *em;
         u64 start = page_offset(page);
         u64 end = start + PAGE_SIZE - 1;
-        struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
-        struct extent_map_tree *map = &BTRFS_I(page->mapping->host)->extent_tree;
+        struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
+        struct extent_io_tree *tree = &btrfs_inode->io_tree;
+        struct extent_map_tree *map = &btrfs_inode->extent_tree;
 
         if (gfpflags_allow_blocking(mask) &&
             page->mapping->host->i_size > SZ_16M) {
@@ -4262,6 +4263,8 @@ int try_release_extent_mapping(struct page *page, gfp_t mask)
                                             extent_map_end(em) - 1,
                                             EXTENT_LOCKED | EXTENT_WRITEBACK,
                                             0, NULL)) {
+                                set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+                                        &btrfs_inode->runtime_flags);
                                 remove_extent_mapping(map, em);
                                 /* once for the rb tree */
                                 free_extent_map(em);