[PATCH v11 3/4] xfs: refactor the usage around xfs_trans_context_{set,clear}

Yafang Shao
2020-12-08T12:29:58Z

The xfs_trans context should be active after it is allocated, and
deactive when it is freed.

So these two helpers are refactored as,
- xfs_trans_context_set()
Used in xfs_trans_alloc()
- xfs_trans_context_clear()
Used in xfs_trans_free()

This patch is based on Darrick's work to fix the issue in xfs/141 in the
earlier version. [1]

1. https://lore.kernel.org/linux-xfs/20201104001649.GN7123@magnolia

Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
fs/xfs/xfs_trans.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 11d390f0d3f2..fe20398a214e 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -67,6 +67,9 @@ xfs_trans_free(
xfs_extent_busy_sort(&tp->t_busy);
xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);

+ /* Detach the transaction from this thread. */
+ xfs_trans_context_clear(tp);
+
trace_xfs_trans_free(tp, _RET_IP_);
if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
sb_end_intwrite(tp->t_mountp->m_super);
@@ -153,9 +156,6 @@ xfs_trans_reserve(
int error = 0;
bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;

- /* Mark this thread as being in a transaction */
- xfs_trans_context_set(tp);
-
/*
* Attempt to reserve the needed disk blocks by decrementing
* the number needed from the number available. This will
@@ -163,10 +163,9 @@ xfs_trans_reserve(
*/
if (blocks > 0) {
error = xfs_mod_fdblocks(mp, -((int64_t)blocks), rsvd);
- if (error != 0) {
- xfs_trans_context_clear(tp);
+ if (error != 0)
return -ENOSPC;
- }
+
tp->t_blk_res += blocks;
}

@@ -241,8 +240,6 @@ xfs_trans_reserve(
tp->t_blk_res = 0;
}

- xfs_trans_context_clear(tp);
-
return error;
}

@@ -284,6 +281,8 @@ xfs_trans_alloc(
INIT_LIST_HEAD(&tp->t_dfops);
tp->t_firstblock = NULLFSBLOCK;

+ /* Mark this thread as being in a transaction */
+ xfs_trans_context_set(tp);
error = xfs_trans_reserve(tp, resp, blocks, rtextents);
if (error) {
xfs_trans_cancel(tp);
@@ -878,7 +877,6 @@ __xfs_trans_commit(

xfs_log_commit_cil(mp, tp, &commit_lsn, regrant);

- xfs_trans_context_clear(tp);
xfs_trans_free(tp);

/*
@@ -911,7 +909,6 @@ __xfs_trans_commit(
tp->t_ticket = NULL;
}

- xfs_trans_context_clear(tp);
xfs_trans_free_items(tp, !!error);
xfs_trans_free(tp);

@@ -971,9 +968,6 @@ xfs_trans_cancel(
tp->t_ticket = NULL;
}

- /* mark this thread as no longer being in a transaction */
- xfs_trans_context_clear(tp);
-
xfs_trans_free_items(tp, dirty);
xfs_trans_free(tp);
}
--
2.18.4