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From: Jan Kara <jack@suse.cz>
To: <linux-fsdevel@vger.kernel.org>
Cc: <linux-ext4@vger.kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	Jan Kara <jack@suse.cz>
Subject: [PATCH 8/9] quota: Set nofs allocation context when acquiring dqio_sem
Date: Tue, 23 Jan 2024 16:25:07 +0100
Message-Id: <20240123152520.4294-8-jack@suse.cz>
In-Reply-To: <20240123152113.13352-1-jack@suse.cz>
References: <20240123152113.13352-1-jack@suse.cz>
Precedence: bulk
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dqio_sem can be acquired during inode reclaim through dquot_drop() ->
dqput() -> dquot_release() -> write_file_info() context. In some cases
(most notably through dquot_get_next_id()) it can be acquired without
holding dquot->dq_lock (which already sets nofs allocation context). So
we need to set nofs allocation context when acquiring it as well.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ocfs2/quota_global.c | 12 ++++++++++++
 fs/ocfs2/quota_local.c  |  3 +++
 fs/quota/quota_v1.c     |  6 ++++++
 fs/quota/quota_v2.c     | 18 ++++++++++++++++++
 4 files changed, 39 insertions(+)

diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index dc9f76ab7e13..0575c2d060eb 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -447,14 +447,17 @@ int ocfs2_global_write_info(struct super_block *sb, int type)
 	int err;
 	struct quota_info *dqopt = sb_dqopt(sb);
 	struct ocfs2_mem_dqinfo *info = dqopt->info[type].dqi_priv;
+	unsigned int memalloc;
 
 	down_write(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	err = ocfs2_qinfo_lock(info, 1);
 	if (err < 0)
 		goto out_sem;
 	err = __ocfs2_global_write_info(sb, type);
 	ocfs2_qinfo_unlock(info, 1);
 out_sem:
+	memalloc_nofs_restore(memalloc);
 	up_write(&dqopt->dqio_sem);
 	return err;
 }
@@ -601,6 +604,7 @@ static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
 	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
 	struct ocfs2_super *osb = OCFS2_SB(sb);
 	int status = 0;
+	unsigned int memalloc;
 
 	trace_ocfs2_sync_dquot_helper(from_kqid(&init_user_ns, dquot->dq_id),
 				      dquot->dq_id.type,
@@ -618,6 +622,7 @@ static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
 		goto out_ilock;
 	}
 	down_write(&sb_dqopt(sb)->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	status = ocfs2_sync_dquot(dquot);
 	if (status < 0)
 		mlog_errno(status);
@@ -625,6 +630,7 @@ static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
 	status = ocfs2_local_write_dquot(dquot);
 	if (status < 0)
 		mlog_errno(status);
+	memalloc_nofs_restore(memalloc);
 	up_write(&sb_dqopt(sb)->dqio_sem);
 	ocfs2_commit_trans(osb, handle);
 out_ilock:
@@ -662,6 +668,7 @@ static int ocfs2_write_dquot(struct dquot *dquot)
 	handle_t *handle;
 	struct ocfs2_super *osb = OCFS2_SB(dquot->dq_sb);
 	int status = 0;
+	unsigned int memalloc;
 
 	trace_ocfs2_write_dquot(from_kqid(&init_user_ns, dquot->dq_id),
 				dquot->dq_id.type);
@@ -673,7 +680,9 @@ static int ocfs2_write_dquot(struct dquot *dquot)
 		goto out;
 	}
 	down_write(&sb_dqopt(dquot->dq_sb)->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	status = ocfs2_local_write_dquot(dquot);
+	memalloc_nofs_restore(memalloc);
 	up_write(&sb_dqopt(dquot->dq_sb)->dqio_sem);
 	ocfs2_commit_trans(osb, handle);
 out:
@@ -920,6 +929,7 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
 	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
 	handle_t *handle;
 	struct ocfs2_super *osb = OCFS2_SB(sb);
+	unsigned int memalloc;
 
 	trace_ocfs2_mark_dquot_dirty(from_kqid(&init_user_ns, dquot->dq_id),
 				     type);
@@ -946,6 +956,7 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
 		goto out_ilock;
 	}
 	down_write(&sb_dqopt(sb)->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	status = ocfs2_sync_dquot(dquot);
 	if (status < 0) {
 		mlog_errno(status);
@@ -954,6 +965,7 @@ static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
 	/* Now write updated local dquot structure */
 	status = ocfs2_local_write_dquot(dquot);
 out_dlock:
+	memalloc_nofs_restore(memalloc);
 	up_write(&sb_dqopt(sb)->dqio_sem);
 	ocfs2_commit_trans(osb, handle);
 out_ilock:
diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index e09842fc9d4d..8ce462c64c51 100644
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -470,6 +470,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode,
 	int bit, chunk;
 	struct ocfs2_recovery_chunk *rchunk, *next;
 	qsize_t spacechange, inodechange;
+	unsigned int memalloc;
 
 	trace_ocfs2_recover_local_quota_file((unsigned long)lqinode->i_ino, type);
 
@@ -521,6 +522,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode,
 				goto out_drop_lock;
 			}
 			down_write(&sb_dqopt(sb)->dqio_sem);
+			memalloc = memalloc_nofs_save();
 			spin_lock(&dquot->dq_dqb_lock);
 			/* Add usage from quota entry into quota changes
 			 * of our node. Auxiliary variables are important
@@ -553,6 +555,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode,
 			unlock_buffer(qbh);
 			ocfs2_journal_dirty(handle, qbh);
 out_commit:
+			memalloc_nofs_restore(memalloc);
 			up_write(&sb_dqopt(sb)->dqio_sem);
 			ocfs2_commit_trans(OCFS2_SB(sb), handle);
 out_drop_lock:
diff --git a/fs/quota/quota_v1.c b/fs/quota/quota_v1.c
index a0db3f195e95..3f3e8acc05db 100644
--- a/fs/quota/quota_v1.c
+++ b/fs/quota/quota_v1.c
@@ -160,9 +160,11 @@ static int v1_read_file_info(struct super_block *sb, int type)
 {
 	struct quota_info *dqopt = sb_dqopt(sb);
 	struct v1_disk_dqblk dqblk;
+	unsigned int memalloc;
 	int ret;
 
 	down_read(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 				sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 	if (ret != sizeof(struct v1_disk_dqblk)) {
@@ -179,6 +181,7 @@ static int v1_read_file_info(struct super_block *sb, int type)
 	dqopt->info[type].dqi_bgrace =
 			dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 out:
+	memalloc_nofs_restore(memalloc);
 	up_read(&dqopt->dqio_sem);
 	return ret;
 }
@@ -187,9 +190,11 @@ static int v1_write_file_info(struct super_block *sb, int type)
 {
 	struct quota_info *dqopt = sb_dqopt(sb);
 	struct v1_disk_dqblk dqblk;
+	unsigned int memalloc;
 	int ret;
 
 	down_write(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 				sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 	if (ret != sizeof(struct v1_disk_dqblk)) {
@@ -209,6 +214,7 @@ static int v1_write_file_info(struct super_block *sb, int type)
 	else if (ret >= 0)
 		ret = -EIO;
 out:
+	memalloc_nofs_restore(memalloc);
 	up_write(&dqopt->dqio_sem);
 	return ret;
 }
diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index ae99e7b88205..48e0d610ceef 100644
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -96,9 +96,11 @@ static int v2_read_file_info(struct super_block *sb, int type)
 	struct qtree_mem_dqinfo *qinfo;
 	ssize_t size;
 	unsigned int version;
+	unsigned int memalloc;
 	int ret;
 
 	down_read(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = v2_read_header(sb, type, &dqhead);
 	if (ret < 0)
 		goto out;
@@ -183,6 +185,7 @@ static int v2_read_file_info(struct super_block *sb, int type)
 		info->dqi_priv = NULL;
 	}
 out:
+	memalloc_nofs_restore(memalloc);
 	up_read(&dqopt->dqio_sem);
 	return ret;
 }
@@ -195,8 +198,10 @@ static int v2_write_file_info(struct super_block *sb, int type)
 	struct mem_dqinfo *info = &dqopt->info[type];
 	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 	ssize_t size;
+	unsigned int memalloc;
 
 	down_write(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	spin_lock(&dq_data_lock);
 	info->dqi_flags &= ~DQF_INFO_DIRTY;
 	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
@@ -209,6 +214,7 @@ static int v2_write_file_info(struct super_block *sb, int type)
 	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
+	memalloc_nofs_restore(memalloc);
 	up_write(&dqopt->dqio_sem);
 	if (size != sizeof(struct v2_disk_dqinfo)) {
 		quota_error(sb, "Can't write info structure");
@@ -328,11 +334,14 @@ static int v2_read_dquot(struct dquot *dquot)
 {
 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 	int ret;
+	unsigned int memalloc;
 
 	down_read(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = qtree_read_dquot(
 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 			dquot);
+	memalloc_nofs_restore(memalloc);
 	up_read(&dqopt->dqio_sem);
 	return ret;
 }
@@ -342,6 +351,7 @@ static int v2_write_dquot(struct dquot *dquot)
 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 	int ret;
 	bool alloc = false;
+	unsigned int memalloc;
 
 	/*
 	 * If space for dquot is already allocated, we don't need any
@@ -355,9 +365,11 @@ static int v2_write_dquot(struct dquot *dquot)
 	} else {
 		down_read(&dqopt->dqio_sem);
 	}
+	memalloc = memalloc_nofs_save();
 	ret = qtree_write_dquot(
 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 			dquot);
+	memalloc_nofs_restore(memalloc);
 	if (alloc)
 		up_write(&dqopt->dqio_sem);
 	else
@@ -368,10 +380,13 @@ static int v2_write_dquot(struct dquot *dquot)
 static int v2_release_dquot(struct dquot *dquot)
 {
 	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
+	unsigned int memalloc;
 	int ret;
 
 	down_write(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
+	memalloc_nofs_restore(memalloc);
 	up_write(&dqopt->dqio_sem);
 
 	return ret;
@@ -386,10 +401,13 @@ static int v2_free_file_info(struct super_block *sb, int type)
 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 {
 	struct quota_info *dqopt = sb_dqopt(sb);
+	unsigned int memalloc;
 	int ret;
 
 	down_read(&dqopt->dqio_sem);
+	memalloc = memalloc_nofs_save();
 	ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
+	memalloc_nofs_restore(memalloc);
 	up_read(&dqopt->dqio_sem);
 	return ret;
 }
-- 
2.35.3