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From: "Yan, Zheng" <zyan@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: idryomov@redhat.com, jlayton@redhat.com
Subject: [PATCH 5/8] ceph: fix dir_lease_is_valid()
Date: Thu, 23 May 2019 16:06:43 +0800	[thread overview]
Message-ID: <20190523080646.19632-5-zyan@redhat.com> (raw)
In-Reply-To: <20190523080646.19632-1-zyan@redhat.com>

It should call __ceph_dentry_dir_lease_touch() under dentry->d_lock.
Besides, ceph_dentry(dentry) can be NULL when called by LOOKUP_RCU
d_revalidate()

Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
---
 fs/ceph/dir.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 0637149fb9f9..1271024a3797 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1512,18 +1512,26 @@ static int __dir_lease_try_check(const struct dentry *dentry)
 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
 {
 	struct ceph_inode_info *ci = ceph_inode(dir);
-	struct ceph_dentry_info *di = ceph_dentry(dentry);
-	int valid = 0;
+	int valid;
+	int shared_gen;
 
 	spin_lock(&ci->i_ceph_lock);
-	if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen)
-		valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
+	valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
+	shared_gen = atomic_read(&ci->i_shared_gen);
 	spin_unlock(&ci->i_ceph_lock);
-	if (valid)
-		__ceph_dentry_dir_lease_touch(di);
-	dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
-	     dir, (unsigned)atomic_read(&ci->i_shared_gen),
-	     dentry, (unsigned)di->lease_shared_gen, valid);
+	if (valid) {
+		struct ceph_dentry_info *di;
+		spin_lock(&dentry->d_lock);
+		di = ceph_dentry(dentry);
+		if (dir == d_inode(dentry->d_parent) &&
+		    di && di->lease_shared_gen == shared_gen)
+			__ceph_dentry_dir_lease_touch(di);
+		else
+			valid = 0;
+		spin_unlock(&dentry->d_lock);
+	}
+	dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
+	     dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
 	return valid;
 }
 
-- 
2.17.2


  parent reply	other threads:[~2019-05-23  8:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23  8:06 [PATCH 1/8] ceph: fix error handling in ceph_get_caps() Yan, Zheng
2019-05-23  8:06 ` [PATCH 2/8] ceph: single workqueue for inode related works Yan, Zheng
2019-05-23  8:06 ` [PATCH 3/8] ceph: avoid iput_final() while holding mutex or in dispatch thread Yan, Zheng
2019-05-23  8:06 ` [PATCH 4/8] ceph: close race between d_name_cmp() and update_dentry_lease() Yan, Zheng
2019-05-23  8:06 ` Yan, Zheng [this message]
2019-05-23  8:06 ` [PATCH 6/8] ceph: use READ_ONCE to access d_parent in RCU critical section Yan, Zheng
2019-05-23  8:06 ` [PATCH 7/8] ceph: ensure d_name/d_parent stability in ceph_mdsc_lease_send_msg() Yan, Zheng
2019-05-23  8:06 ` [PATCH 8/8] ceph: hold i_ceph_lock when removing caps for freeing inode Yan, Zheng
2019-05-29 13:14   ` Sasha Levin
2019-05-30  1:46     ` Yan, Zheng
2019-08-02  8:13       ` Greg KH

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