Re: [PATCH V7 13/17] xfs: xfs_growfs_rt_alloc: Unlock inode explicitly rather than through iop_committing()

Darrick J. Wong
2022-03-02T00:26:14Z

On Tue, Mar 01, 2022 at 04:09:34PM +0530, Chandan Babu R wrote:
> In order to be able to upgrade inodes to XFS_DIFLAG2_NREXT64, a future commit
> will perform such an upgrade in a transaction context. This requires the
> transaction to be rolled once. Hence inodes which have been added to the
> tranasction (via xfs_trans_ijoin()) with non-zero value for lock_flags
> argument would cause the inode to be unlocked when the transaction is rolled.
>
> To prevent this from happening in the case of realtime bitmap/summary inodes,
> this commit now unlocks the inode explictly rather than through
> iop_committing() call back.
>
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
> ---
> fs/xfs/xfs_rtalloc.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index b8c79ee791af..a70140b35e8b 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -780,6 +780,7 @@ xfs_growfs_rt_alloc(
> int resblks; /* space reservation */
> enum xfs_blft buf_type;
> struct xfs_trans *tp;
> + bool unlock_inode;
>
> if (ip == mp->m_rsumip)
> buf_type = XFS_BLFT_RTSUMMARY_BUF;
> @@ -802,7 +803,8 @@ xfs_growfs_rt_alloc(
> * Lock the inode.
> */
> xfs_ilock(ip, XFS_ILOCK_EXCL);
> - xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
> + xfs_trans_ijoin(tp, ip, 0);
> + unlock_inode = true;
>
> error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
> XFS_IEXT_ADD_NOSPLIT_CNT);
> @@ -823,8 +825,11 @@ xfs_growfs_rt_alloc(
> * Free any blocks freed up in the transaction, then commit.
> */
> error = xfs_trans_commit(tp);
> - if (error)
> + unlock_inode = false;
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> + if (error)
> return error;

Whitespace corruption here?

Other than that ... let's see, the ILOCK/ijoin in the inner loop that
zeroes the new bitmap/summary blocks doesn't require an explicit unlock,
so I think this looks fine now.

So with that fixed,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> +
> /*
> * Now we need to clear the allocated blocks.
> * Do this one block per transaction, to keep it simple.
> @@ -874,6 +879,8 @@ xfs_growfs_rt_alloc(
>
> out_trans_cancel:
> xfs_trans_cancel(tp);
> + if (unlock_inode)
> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
> return error;
> }
>
> --
> 2.30.2
>