ceph: handle LOOKUP_RCU in ceph_d_revalidate
We can now handle the snapshot cases under RCU, as well as the
non-snapshot case when we don't need to queue up a lease renewal
allow LOOKUP_RCU walks to proceed under those conditions.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 60dcca1..c64a0b7 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1214,15 +1214,19 @@
struct dentry *parent;
struct inode *dir;
- if (flags & LOOKUP_RCU)
- return -ECHILD;
+ if (flags & LOOKUP_RCU) {
+ parent = ACCESS_ONCE(dentry->d_parent);
+ dir = d_inode_rcu(parent);
+ if (!dir)
+ return -ECHILD;
+ } else {
+ parent = dget_parent(dentry);
+ dir = d_inode(parent);
+ }
dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
- parent = dget_parent(dentry);
- dir = d_inode(parent);
-
/* always trust cached snapped dentries, snapdir dentry */
if (ceph_snap(dir) != CEPH_NOSNAP) {
dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
@@ -1249,6 +1253,9 @@
struct ceph_mds_request *req;
int op, mask, err;
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
op = ceph_snap(dir) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
@@ -1284,7 +1291,8 @@
ceph_dir_clear_complete(dir);
}
- dput(parent);
+ if (!(flags & LOOKUP_RCU))
+ dput(parent);
return valid;
}