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From: Andreas Gruenbacher <agruenba@redhat.com>
To: gfs2@lists.linux.dev
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Subject: [PATCH 11/13] gfs2: Get rid of some unnecessary quota locking
Date: Tue, 18 Jun 2024 18:05:15 +0200	[thread overview]
Message-ID: <20240618160517.901589-12-agruenba@redhat.com> (raw)
In-Reply-To: <20240618160517.901589-1-agruenba@redhat.com>

With the locking the previous patch has introduced for each struct
gfs2_quota_data object, sd_quota_mutex has become largely irrelevant.
By waiting on the buffer head instead of waiting on the mutex in
get_bh(), it becomes completely irrelevant and can be removed.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/incore.h     |  1 -
 fs/gfs2/ops_fstype.c |  1 -
 fs/gfs2/quota.c      | 55 +++++++++++++++++++++++---------------------
 3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 90fd2584357a..aa4ef67a34e0 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -782,7 +782,6 @@ struct gfs2_sbd {
 
 	struct list_head sd_quota_list;
 	atomic_t sd_quota_count;
-	struct mutex sd_quota_mutex;
 	struct mutex sd_quota_sync_mutex;
 	wait_queue_head_t sd_quota_wait;
 
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0561edd6cc86..ff1f3e3dc65c 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -103,7 +103,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 	init_completion(&sdp->sd_journal_ready);
 
 	INIT_LIST_HEAD(&sdp->sd_quota_list);
-	mutex_init(&sdp->sd_quota_mutex);
 	mutex_init(&sdp->sd_quota_sync_mutex);
 	init_waitqueue_head(&sdp->sd_quota_wait);
 	spin_lock_init(&sdp->sd_bitmap_lock);
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 283c6ff21911..2490117afb96 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -397,16 +397,17 @@ static int bh_get(struct gfs2_quota_data *qd)
 	struct inode *inode = sdp->sd_qc_inode;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	unsigned int block, offset;
-	struct buffer_head *bh;
+	struct buffer_head *bh = NULL;
 	struct iomap iomap = { };
 	int error;
 
-	mutex_lock(&sdp->sd_quota_mutex);
-
-	if (qd->qd_bh_count++) {
-		mutex_unlock(&sdp->sd_quota_mutex);
+	spin_lock(&qd->qd_lockref.lock);
+	if (qd->qd_bh_count) {
+		qd->qd_bh_count++;
+		spin_unlock(&qd->qd_lockref.lock);
 		return 0;
 	}
+	spin_unlock(&qd->qd_lockref.lock);
 
 	block = qd->qd_slot / sdp->sd_qc_per_block;
 	offset = qd->qd_slot % sdp->sd_qc_per_block;
@@ -415,48 +416,52 @@ static int bh_get(struct gfs2_quota_data *qd)
 			       (loff_t)block << inode->i_blkbits,
 			       i_blocksize(inode), &iomap);
 	if (error)
-		goto fail;
+		return error;
 	error = -ENOENT;
 	if (iomap.type != IOMAP_MAPPED)
-		goto fail;
+		return error;
 
 	error = gfs2_meta_read(ip->i_gl, iomap.addr >> inode->i_blkbits,
 			       DIO_WAIT, 0, &bh);
 	if (error)
-		goto fail;
+		return error;
 	error = -EIO;
 	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
-		goto fail_brelse;
-
-	qd->qd_bh = bh;
-	qd->qd_bh_qc = (struct gfs2_quota_change *)
-		(bh->b_data + sizeof(struct gfs2_meta_header) +
-		 offset * sizeof(struct gfs2_quota_change));
-
-	mutex_unlock(&sdp->sd_quota_mutex);
+		goto out;
 
-	return 0;
+	spin_lock(&qd->qd_lockref.lock);
+	if (qd->qd_bh == NULL) {
+		qd->qd_bh = bh;
+		qd->qd_bh_qc = (struct gfs2_quota_change *)
+			(bh->b_data + sizeof(struct gfs2_meta_header) +
+			 offset * sizeof(struct gfs2_quota_change));
+		bh = NULL;
+	}
+	qd->qd_bh_count++;
+	spin_unlock(&qd->qd_lockref.lock);
+	error = 0;
 
-fail_brelse:
+out:
 	brelse(bh);
-fail:
-	qd->qd_bh_count--;
-	mutex_unlock(&sdp->sd_quota_mutex);
 	return error;
 }
 
 static void bh_put(struct gfs2_quota_data *qd)
 {
 	struct gfs2_sbd *sdp = qd->qd_sbd;
+	struct buffer_head *bh = NULL;
 
-	mutex_lock(&sdp->sd_quota_mutex);
+	spin_lock(&qd->qd_lockref.lock);
 	gfs2_assert(sdp, qd->qd_bh_count);
 	if (!--qd->qd_bh_count) {
-		brelse(qd->qd_bh);
+		bh = qd->qd_bh;
 		qd->qd_bh = NULL;
 		qd->qd_bh_qc = NULL;
 	}
-	mutex_unlock(&sdp->sd_quota_mutex);
+	spin_unlock(&qd->qd_lockref.lock);
+
+	if (bh)
+		brelse(bh);
 }
 
 static bool qd_grab_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
@@ -676,7 +681,6 @@ static void do_qc(struct gfs2_quota_data *qd, s64 change)
 	bool needs_put = false;
 	s64 x;
 
-	mutex_lock(&sdp->sd_quota_mutex);
 	gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
 
 	/*
@@ -720,7 +724,6 @@ static void do_qc(struct gfs2_quota_data *qd, s64 change)
 	}
 	if (change < 0) /* Reset quiet flag if we freed some blocks */
 		clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
-	mutex_unlock(&sdp->sd_quota_mutex);
 }
 
 static int gfs2_write_buf_to_page(struct gfs2_sbd *sdp, unsigned long index,
-- 
2.45.1


  parent reply	other threads:[~2024-06-18 16:05 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-18 16:05 [PATCH 00/13] gfs2: quota changes Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 01/13] gfs2: Minor gfs2_quota_init error path cleanup Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 02/13] gfs2: Check quota consistency on mount Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 03/13] gfs2: Revert "introduce qd_bh_get_or_undo" Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 04/13] gfs2: qd_check_sync cleanups Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 05/13] gfs2: Revert "ignore negated quota changes" Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 06/13] gfs2: Revert "Add quota_change type" Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 07/13] gfs2: Fix and clean up function do_qc Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 08/13] gfs2: quota need_sync cleanup Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 09/13] gfs2: Fold qd_fish into gfs2_quota_sync Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 10/13] gfs2: Add some missing quota locking Andreas Gruenbacher
2024-06-18 16:05 ` Andreas Gruenbacher [this message]
2024-06-20 14:22   ` [PATCH 11/13] gfs2: Get rid of some unnecessary " Alexander Aring
2024-06-20 14:45     ` Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 12/13] gfs2: Be more careful with the quota sync generation Andreas Gruenbacher
2024-06-18 16:05 ` [PATCH 13/13] gfs2: Revert "check for no eligible quota changes" Andreas Gruenbacher

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