[PATCH] vfs: show filesystem name at dump_inode()

[Tetsuo Handa]

Commit 8b17e540969a ("vfs: add initial support for CONFIG_DEBUG_VFS") added
dump_inode(), but dump_inode() currently reports only raw pointer address.
Comment says that adding a proper inode dumping routine is a TODO.

However, syzkaller concurrently tests multiple filesystems, and several
filesystems started calling dump_inode() due to hitting VFS_BUG_ON_INODE()
added by commit af153bb63a33 ("vfs: catch invalid modes in may_open()")
before a proper inode dumping routine is implemented.

Show filesystem name at dump_inode() so that we can find which filesystem
has passed an invalid mode to may_open() from syzkaller's crash reports.

Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
---
 fs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/inode.c b/fs/inode.c
index 01ebdc40021e..8a60aec94245 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2914,7 +2914,7 @@ EXPORT_SYMBOL(mode_strip_sgid);
  */
 void dump_inode(struct inode *inode, const char *reason)
 {
-       pr_warn("%s encountered for inode %px", reason, inode);
+	pr_warn("%s encountered for inode %px (%s)\n", reason, inode, inode->i_sb->s_type->name);
 }
 
 EXPORT_SYMBOL(dump_inode);
-- 
2.50.1