ceph: protect d_parent access in ceph_d_revalidate
Protect d_parent with d_lock. Carry a reference. Simplify the flow so
that there is a single exit point and cleanup.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index ed296ec..31d27f8 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1024,36 +1024,38 @@
*/
static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ int valid = 0;
struct inode *dir;
if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
- dir = dentry->d_parent->d_inode;
-
dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
ceph_dentry(dentry)->offset);
+ dir = ceph_get_dentry_parent_inode(dentry);
+
/* always trust cached snapped dentries, snapdir dentry */
if (ceph_snap(dir) != CEPH_NOSNAP) {
dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
- goto out_touch;
+ valid = 1;
+ } else if (dentry->d_inode &&
+ ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) {
+ valid = 1;
+ } else if (dentry_lease_is_valid(dentry) ||
+ dir_lease_is_valid(dir, dentry)) {
+ valid = 1;
}
- if (dentry->d_inode && ceph_snap(dentry->d_inode) == CEPH_SNAPDIR)
- goto out_touch;
- if (dentry_lease_is_valid(dentry) ||
- dir_lease_is_valid(dir, dentry))
- goto out_touch;
-
- dout("d_revalidate %p invalid\n", dentry);
- d_drop(dentry);
- return 0;
-out_touch:
- ceph_dentry_lru_touch(dentry);
- return 1;
+ dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
+ if (valid)
+ ceph_dentry_lru_touch(dentry);
+ else
+ d_drop(dentry);
+ iput(dir);
+ return valid;
}
/*