3 files changed, 20 insertions, 0 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 86249cf78897..ccb30ca9ebb2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -59,6 +59,7 @@
 #include "props.h"
 #include "sysfs.h"
 #include "qgroup.h"
+#include "tree-log.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
@@ -2521,6 +2522,8 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 out_end_trans:
         trans->block_rsv = NULL;
         trans->bytes_reserved = 0;
+        if (!err)
+                btrfs_record_snapshot_destroy(trans, dir);
         ret = btrfs_end_transaction(trans, root);
         if (ret && !err)
                 err = ret;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 978c3a810893..43c6781af654 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -5498,6 +5498,21 @@ record:
 }
 
 /*
+ * Make sure that if someone attempts to fsync the parent directory of a deleted
+ * snapshot, it ends up triggering a transaction commit. This is to guarantee
+ * that after replaying the log tree of the parent directory's root we will not
+ * see the snapshot anymore and at log replay time we will not see any log tree
+ * corresponding to the deleted snapshot's root, which could lead to replaying
+ * it after replaying the log tree of the parent directory (which would replay
+ * the snapshot delete operation).
+ */
+void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
+                                   struct inode *dir)
+{
+        BTRFS_I(dir)->last_unlink_trans = trans->transid;
+}
+
+/*
  * Call this after adding a new name for a file and it will properly
  * update the log to reflect the new name.
  *
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 6916a781ea02..a9f1b75d080d 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -79,6 +79,8 @@ int btrfs_pin_log_trans(struct btrfs_root *root);
 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
                              struct inode *dir, struct inode *inode,
                              int for_rename);
+void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
+                                   struct inode *dir);
 int btrfs_log_new_name(struct btrfs_trans_handle *trans,
                         struct inode *inode, struct inode *old_dir,
                         struct dentry *parent);