[PATCH v2] btrfs: trace use file_inode(file)->i_sb to calculate fs_info

[Goldwyn Rodrigues <rgoldwyn@suse.de>]

If overlay is used on top of btrfs, dentry->d_sb translates to overlay's
super block and fsid assignment will lead to a crash.

Use file_inode(file)->i_sb to always get btrfs_sb.

Changes since v1:
  Changed subject to include trace
  Use file_inode() to get inode pointer

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Boris Burkov <boris@bur.io>
---
 include/trace/events/btrfs.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 125bdc166bfe..92118df217b4 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -770,9 +770,9 @@ TRACE_EVENT(btrfs_sync_file,
 
 	TP_fast_assign(
 		const struct dentry *dentry = file->f_path.dentry;
-		const struct inode *inode = d_inode(dentry);
+		const struct inode *inode = file_inode(file);
 
-		TP_fast_assign_fsid(btrfs_sb(file->f_path.dentry->d_sb));
+		TP_fast_assign_fsid(btrfs_sb(inode->i_sb));
 		__entry->ino		= btrfs_ino(BTRFS_I(inode));
 		__entry->parent		= btrfs_ino(BTRFS_I(d_inode(dentry->d_parent)));
 		__entry->datasync	= datasync;
-- 
2.53.0


-- 
Goldwyn