[PATCH 2/7] xfs: Increase XFS_QM_TRANS_MAXDQS to 5

Darrick J. Wong
2024-04-10T00:48:02Z

From: Allison Henderson <allison.henderson@oracle.com>

With parent pointers enabled, a rename operation can update up to 5
inodes: src_dp, target_dp, src_ip, target_ip and wip. This causes
their dquots to a be attached to the transaction chain, so we need
to increase XFS_QM_TRANS_MAXDQS. This patch also add a helper
function xfs_dqlockn to lock an arbitrary number of dquots.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_dquot.c | 41 +++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_dquot.h | 1 +
fs/xfs/xfs_qm.h | 2 +-
fs/xfs/xfs_trans_dquot.c | 15 ++++++++++-----
4 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index c98cb468c3578..13aba84bd64af 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -1371,6 +1371,47 @@ xfs_dqlock2(
}
}

+static int
+xfs_dqtrx_cmp(
+ const void *a,
+ const void *b)
+{
+ const struct xfs_dqtrx *qa = a;
+ const struct xfs_dqtrx *qb = b;
+
+ if (qa->qt_dquot->q_id > qb->qt_dquot->q_id)
+ return 1;
+ if (qa->qt_dquot->q_id < qb->qt_dquot->q_id)
+ return -1;
+ return 0;
+}
+
+void
+xfs_dqlockn(
+ struct xfs_dqtrx *q)
+{
+ unsigned int i;
+
+ BUILD_BUG_ON(XFS_QM_TRANS_MAXDQS > MAX_LOCKDEP_SUBCLASSES);
+
+ /* Sort in order of dquot id, do not allow duplicates */
+ for (i = 0; i < XFS_QM_TRANS_MAXDQS && q[i].qt_dquot != NULL; i++) {
+ unsigned int j;
+
+ for (j = 0; j < i; j++)
+ ASSERT(q[i].qt_dquot != q[j].qt_dquot);
+ }
+ if (i == 0)
+ return;
+
+ sort(q, i, sizeof(struct xfs_dqtrx), xfs_dqtrx_cmp, NULL);
+
+ mutex_lock(&q[0].qt_dquot->q_qlock);
+ for (i = 1; i < XFS_QM_TRANS_MAXDQS && q[i].qt_dquot != NULL; i++)
+ mutex_lock_nested(&q[i].qt_dquot->q_qlock,
+ XFS_QLOCK_NESTED + i - 1);
+}
+
int __init
xfs_qm_init(void)
{
diff --git a/fs/xfs/xfs_dquot.h b/fs/xfs/xfs_dquot.h
index 956272d9b302f..677bb2dc9ac91 100644
--- a/fs/xfs/xfs_dquot.h
+++ b/fs/xfs/xfs_dquot.h
@@ -223,6 +223,7 @@ int xfs_qm_dqget_uncached(struct xfs_mount *mp,
void xfs_qm_dqput(struct xfs_dquot *dqp);

void xfs_dqlock2(struct xfs_dquot *, struct xfs_dquot *);
+void xfs_dqlockn(struct xfs_dqtrx *q);

void xfs_dquot_set_prealloc_limits(struct xfs_dquot *);

diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index f5993012bf98f..6e09dfcd13e25 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -136,7 +136,7 @@ enum {
XFS_QM_TRANS_PRJ,
XFS_QM_TRANS_DQTYPES
};
-#define XFS_QM_TRANS_MAXDQS 2
+#define XFS_QM_TRANS_MAXDQS 5
struct xfs_dquot_acct {
struct xfs_dqtrx dqs[XFS_QM_TRANS_DQTYPES][XFS_QM_TRANS_MAXDQS];
};
diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index 577b535a595cb..b368e13424c4f 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c
@@ -379,24 +379,29 @@ xfs_trans_mod_dquot(

/*
* Given an array of dqtrx structures, lock all the dquots associated and join
- * them to the transaction, provided they have been modified. We know that the
- * highest number of dquots of one type - usr, grp and prj - involved in a
- * transaction is 3 so we don't need to make this very generic.
+ * them to the transaction, provided they have been modified.
*/
STATIC void
xfs_trans_dqlockedjoin(
struct xfs_trans *tp,
struct xfs_dqtrx *q)
{
+ unsigned int i;
ASSERT(q[0].qt_dquot != NULL);
if (q[1].qt_dquot == NULL) {
xfs_dqlock(q[0].qt_dquot);
xfs_trans_dqjoin(tp, q[0].qt_dquot);
- } else {
- ASSERT(XFS_QM_TRANS_MAXDQS == 2);
+ } else if (q[2].qt_dquot == NULL) {
xfs_dqlock2(q[0].qt_dquot, q[1].qt_dquot);
xfs_trans_dqjoin(tp, q[0].qt_dquot);
xfs_trans_dqjoin(tp, q[1].qt_dquot);
+ } else {
+ xfs_dqlockn(q);
+ for (i = 0; i < XFS_QM_TRANS_MAXDQS; i++) {
+ if (q[i].qt_dquot == NULL)
+ break;
+ xfs_trans_dqjoin(tp, q[i].qt_dquot);
+ }
}
}