[2/3] gfs2: switch to lockref_init(..., 1)

Commit Message

Andreas Gruenbacher Jan. 29, 2025, 2:33 p.m. UTC

In qd_alloc(), initialize the lockref count to 1 to cover the common
case.  Compensate for that in gfs2_quota_init() by adjusting the count
back down to 0; this only occurs when mounting the filesystem rw.

Signed-off-by: Andreas Gruenbacher <[e-mail]>
---
 fs/gfs2/quota.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig Jan. 29, 2025, 4:50 p.m. UTC | #1

On Wed, Jan 29, 2025 at 03:33:51PM +0100, Andreas Gruenbacher wrote:
> In qd_alloc(), initialize the lockref count to 1 to cover the common
> case.  Compensate for that in gfs2_quota_init() by adjusting the count
> back down to 0; this only occurs when mounting the filesystem rw.

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 58bc5013ca49..6ae529a5388b 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -236,7 +236,7 @@  static struct gfs2_quota_data *qd_alloc(unsigned hash, struct gfs2_sbd *sdp, str
 		return NULL;
 
 	qd->qd_sbd = sdp;
-	lockref_init(&qd->qd_lockref, 0);
+	lockref_init(&qd->qd_lockref, 1);
 	qd->qd_id = qid;
 	qd->qd_slot = -1;
 	INIT_LIST_HEAD(&qd->qd_lru);
@@ -297,7 +297,6 @@  static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
 	spin_lock_bucket(hash);
 	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
 	if (qd == NULL) {
-		new_qd->qd_lockref.count++;
 		*qdp = new_qd;
 		list_add(&new_qd->qd_list, &sdp->sd_quota_list);
 		hlist_bl_add_head_rcu(&new_qd->qd_hlist, &qd_hash_table[hash]);
@@ -1450,6 +1449,7 @@  int gfs2_quota_init(struct gfs2_sbd *sdp)
 			if (qd == NULL)
 				goto fail_brelse;
 
+			qd->qd_lockref.count = 0;
 			set_bit(QDF_CHANGE, &qd->qd_flags);
 			qd->qd_change = qc_change;
 			qd->qd_slot = slot;