Commit 10ee2526 authored Jun 21, 2018 by Darrick J. Wong

xfs: allow empty transactions while frozen



In commit e89c0413 ("xfs: implement the GETFSMAP ioctl") we
created the ability to obtain empty transactions.  These transactions
have no log or block reservations and therefore can't modify anything.
Since they're also NO_WRITECOUNT they can run while the fs is frozen,
so we don't need to WARN_ON about that usage.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

parent e53946db

fs/xfs/xfs_trans.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -258,7 +258,12 @@ xfs_trans_alloc(
		if (!(flags & XFS_TRANS_NO_WRITECOUNT))
		sb_start_intwrite(mp->m_super);

		WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
		/*
		* Zero-reservation ("empty") transactions can't modify anything, so
		* they're allowed to run while we're frozen.
		*/
		WARN_ON(resp->tr_logres > 0 &&
		mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
		atomic_inc(&mp->m_active_trans);

		tp = kmem_zone_zalloc(xfs_trans_zone,

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