From 9358c6d4c0264b1572554c49c4b92673ea9a5c72 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 30 Mar 2010 13:54:41 -0700 Subject: ceph: fix dentry rehashing on virtual .snap dir If a lookup fails on the magic .snap directory, we bind it to a magic snap directory inode in ceph_lookup_finish(). That code assumes the dentry is unhashed, but a recent server-side change started returning NULL leases on lookup failure, causing the .snap dentry to be hashed and NULL by ceph_fill_trace(). This causes dentry hash chain corruption, or a dies when d_rehash() includes BUG_ON(!d_unhashed(entry)); So, avoid processing the NULL dentry lease if it the dentry matches the snapdir name in ceph_fill_trace(). That allows the lookup completion to properly bind it to the snapdir inode. BUG there if dentry is hashed to be sure. Signed-off-by: Sage Weil --- fs/ceph/dir.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ceph/dir.c') diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 8a9116e15b7..aed8fda3302 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -488,6 +488,7 @@ struct dentry *ceph_finish_lookup(struct ceph_mds_request *req, struct inode *inode = ceph_get_snapdir(parent); dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n", dentry, dentry->d_name.len, dentry->d_name.name, inode); + BUG_ON(!d_unhashed(dentry)); d_add(dentry, inode); err = 0; } -- cgit v1.2.3-70-g09d2