quota: Set nofs allocation context when acquiring dqio_sem

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>

2 files changed, 24 insertions, 0 deletions

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 @@ out_free:
 		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;
 }