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>
This commit is contained in:
Jeff Layton 2016-07-01 09:39:21 -04:00 committed by Ilya Dryomov
parent 14fb9c9efe
commit f49d1e058d

View File

@ -1214,15 +1214,19 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
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 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
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 @@ static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
ceph_dir_clear_complete(dir);
}
dput(parent);
if (!(flags & LOOKUP_RCU))
dput(parent);
return valid;
}