Commit ace74e79 authored Oct 08, 2020 by Darrick J. Wong

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>

parent 7249c95a

fs/xfs/xfs_rtalloc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1024,7 +1024,7 @@ xfs_growfs_rt(
		/*
		* Lock out other callers by grabbing the bitmap inode lock.
		*/
		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL \| XFS_ILOCK_RTBITMAP);
		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
		/*
		* Update the bitmap inode's size ondisk and incore. We need
		@@ -1038,7 +1038,7 @@ xfs_growfs_rt(
		/*
		* Get the summary inode into the transaction.
		*/
		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL);
		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL \| XFS_ILOCK_RTSUM);
		xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
		/*
		* Update the summary inode's size. We need to update the

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