Thread (26 messages) 26 messages, 4 authors, 2014-06-04
STALE4385d

[PATCH 1/5] quota: protect Q_GETFMT by dqonoff_mutex

From: Niu Yawei <hidden>
Date: 2014-06-04 04:19:12
Also in: linux-fsdevel
Subsystem: diskquota, filesystems (vfs and infrastructure), the rest · Maintainers: Jan Kara, Alexander Viro, Christian Brauner, Linus Torvalds

Subject: [PATCH 1/5] quota: protect Q_GETFMT by dqonoff_mutex

dqptr_sem will go away. Protect Q_GETFMT quotactl by
dqonoff_mutex instead. This is also enough to make sure
quota info will not go away while we are looking at it.

Signed-off-by: Lai Siyao <redacted>
Signed-off-by: Niu Yawei <redacted>
---
 fs/quota/quota.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 2b363e2..e4851cb 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -79,13 +79,13 @@ static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
 {
 	__u32 fmt;
 
-	down_read(&sb_dqopt(sb)->dqptr_sem);
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
 	if (!sb_has_quota_active(sb, type)) {
-		up_read(&sb_dqopt(sb)->dqptr_sem);
+		mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 		return -ESRCH;
 	}
 	fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id;
-	up_read(&sb_dqopt(sb)->dqptr_sem);
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
 	if (copy_to_user(addr, &fmt, sizeof(fmt)))
 		return -EFAULT;
 	return 0;
-- 
1.7.1

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