diff options
| author | Jeff Layton <jlayton@kernel.org> | 2019-04-15 18:00:42 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2019-04-23 21:37:54 +0200 |
| commit | 4b8222870032715f9d995f3eb7c7acd8379a275d (patch) | |
| tree | 922907eb1251073439bc094e76800b7f1188c098 /fs | |
| parent | ceph: ensure d_name stability in ceph_dentry_hash() (diff) | |
| download | linux-4b8222870032715f9d995f3eb7c7acd8379a275d.tar.xz linux-4b8222870032715f9d995f3eb7c7acd8379a275d.zip | |
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.c | 16 |
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) || |