xfs: annotate grabbing the realtime bitmap/summary locks in growfs
authorDarrick J. Wong <darrick.wong@oracle.com>
Thu, 8 Oct 2020 14:53:33 +0000 (07:53 -0700)
committerDarrick J. Wong <darrick.wong@oracle.com>
Tue, 13 Oct 2020 15:41:31 +0000 (08:41 -0700)
commitace74e797a82f7ded7912dfa285bd954cc66400d
treeb1dc5dccae281995a44880758d58aa01d3da2c8e
parent7249c95a3fd72c7f47ede0275b9fc4535db43e48
xfs: annotate grabbing the realtime bitmap/summary locks in growfs

Use XFS_ILOCK_RT{BITMAP,SUM} to annotate grabbing the rt bitmap and
summary locks when we grow the realtime volume, just like we do most
everywhere else.  This shuts up lockdep warnings about grabbing the
ILOCK class of locks recursively:

============================================
WARNING: possible recursive locking detected
5.9.0-rc4-djw #rc4 Tainted: G           O
--------------------------------------------
xfs_growfs/4841 is trying to acquire lock:
ffff888035acc230 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_ilock+0xac/0x1a0 [xfs]

but task is already holding lock:
ffff888035acedb0 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_ilock+0xac/0x1a0 [xfs]

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&xfs_nondir_ilock_class);
  lock(&xfs_nondir_ilock_class);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
fs/xfs/xfs_rtalloc.c