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authorJeff Layton <jlayton@kernel.org>2019-04-15 12:00:42 -0400
committerIlya Dryomov <idryomov@gmail.com>2019-04-23 21:37:54 +0200
commit4b8222870032715f9d995f3eb7c7acd8379a275d (patch)
tree922907eb1251073439bc094e76800b7f1188c098 /fs
parent76a495d666e5043ffc315695f8241f5e94a98849 (diff)
ceph: handle the case where a dentry has been renamed on outstanding req
It's possible for us to issue a lookup to revalidate a dentry concurrently with a rename. If done in the right order, then we could end up processing dentry info in the reply that no longer reflects the state of the dentry. If req->r_dentry->d_name differs from the one in the trace, then just ignore the trace in the reply. We only need to do this however if the parent's i_rwsem is not held. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/ceph/inode.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2d61ddda9bf5..c2feb310ac1e 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1163,6 +1163,19 @@ static int splice_dentry(struct dentry **pdn, struct inode *in)
return 0;
}
+static int d_name_cmp(struct dentry *dentry, const char *name, size_t len)
+{
+ int ret;
+
+ /* take d_lock to ensure dentry->d_name stability */
+ spin_lock(&dentry->d_lock);
+ ret = dentry->d_name.len - len;
+ if (!ret)
+ ret = memcmp(dentry->d_name.name, name, len);
+ spin_unlock(&dentry->d_lock);
+ return ret;
+}
+
/*
* Incorporate results into the local cache. This is either just
* one inode, or a directory, dentry, and possibly linked-to inode (e.g.,
@@ -1412,7 +1425,8 @@ retry_lookup:
err = splice_dentry(&req->r_dentry, in);
if (err < 0)
goto done;
- } else if (rinfo->head->is_dentry) {
+ } else if (rinfo->head->is_dentry &&
+ !d_name_cmp(req->r_dentry, rinfo->dname, rinfo->dname_len)) {
struct ceph_vino *ptvino = NULL;
if ((le32_to_cpu(rinfo->diri.in->cap.caps) & CEPH_CAP_FILE_SHARED) ||