[PATCH 07/15] reconnect_one(): use lookup_one_len_unlocked()

From: Al Viro
Date: Fri Apr 15 2016 - 20:58:51 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

... and explain the non-obvious logics in case when lookup yields
a different dentry.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/exportfs/expfs.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index c46f1a1..402c5ca 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -143,14 +143,18 @@ static struct dentry *reconnect_one(struct vfsmount *mnt,
if (err)
goto out_err;
dprintk("%s: found name: %s\n", __func__, nbuf);
- inode_lock(parent->d_inode);
- tmp = lookup_one_len(nbuf, parent, strlen(nbuf));
- inode_unlock(parent->d_inode);
+ tmp = lookup_one_len_unlocked(nbuf, parent, strlen(nbuf));
if (IS_ERR(tmp)) {
dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp));
goto out_err;
}
if (tmp != dentry) {
+ /*
+ * Somebody has renamed it since exportfs_get_name();
+ * great, since it could've only been renamed if it
+ * got looked up and thus connected, and it would
+ * remain connected afterwards. We are done.
+ */
dput(tmp);
goto out_reconnected;
}
--
2.8.0.rc3