From eb6bb1c5bdc6e455a9d16cb845cc65afc9b0a617 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Mon, 16 Aug 2010 09:21:27 -0700 Subject: ceph: direct requests in snapped namespace based on nonsnap parent When making a request in the virtual snapdir or a snapped portion of the namespace, we should choose the MDS based on the first nonsnap parent (and its caps). If that is not the best place, we will get forward hints to find the right MDS in the cluster. This fixes ESTALE errors when using the .snap directory and namespace with multiple MDSs. Signed-off-by: Sage Weil --- fs/ceph/mds_client.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 397a47b696ce..8d1f11c7a5a2 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -560,6 +560,13 @@ static void __unregister_request(struct ceph_mds_client *mdsc, * * Called under mdsc->mutex. */ +struct dentry *get_nonsnap_parent(struct dentry *dentry) +{ + while (!IS_ROOT(dentry) && ceph_snap(dentry->d_inode) != CEPH_NOSNAP) + dentry = dentry->d_parent; + return dentry; +} + static int __choose_mds(struct ceph_mds_client *mdsc, struct ceph_mds_request *req) { @@ -590,14 +597,29 @@ static int __choose_mds(struct ceph_mds_client *mdsc, if (req->r_inode) { inode = req->r_inode; } else if (req->r_dentry) { - if (req->r_dentry->d_inode) { + struct inode *dir = req->r_dentry->d_parent->d_inode; + + if (dir->i_sb != mdsc->client->sb) { + /* not this fs! */ + inode = req->r_dentry->d_inode; + } else if (ceph_snap(dir) != CEPH_NOSNAP) { + /* direct snapped/virtual snapdir requests + * based on parent dir inode */ + struct dentry *dn = + get_nonsnap_parent(req->r_dentry->d_parent); + inode = dn->d_inode; + dout("__choose_mds using nonsnap parent %p\n", inode); + } else if (req->r_dentry->d_inode) { + /* dentry target */ inode = req->r_dentry->d_inode; } else { - inode = req->r_dentry->d_parent->d_inode; + /* dir + name */ + inode = dir; hash = req->r_dentry->d_name.hash; is_hash = true; } } + dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash, (int)hash, mode); if (!inode) -- cgit v1.2.3