ceph: fix race between cap issue and revoke
If we receive new caps from the auth MDS and the non-auth MDS is
revoking the newly issued caps, we should release the caps from
the non-auth MDS. The scenario is filelock's state changes from
SYNC to LOCK. Non-auth MDS revokes Fc cap, the client gets Fc cap
from the auth MDS at the same time.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7045a8d..25442b4 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -806,22 +806,28 @@
/*
* Return true if mask caps are currently being revoked by an MDS.
*/
+int __ceph_caps_revoking_other(struct ceph_inode_info *ci,
+ struct ceph_cap *ocap, int mask)
+{
+ struct ceph_cap *cap;
+ struct rb_node *p;
+
+ for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
+ cap = rb_entry(p, struct ceph_cap, ci_node);
+ if (cap != ocap && __cap_is_valid(cap) &&
+ (cap->implemented & ~cap->issued & mask))
+ return 1;
+ }
+ return 0;
+}
+
int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
{
struct inode *inode = &ci->vfs_inode;
- struct ceph_cap *cap;
- struct rb_node *p;
- int ret = 0;
+ int ret;
spin_lock(&ci->i_ceph_lock);
- for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
- cap = rb_entry(p, struct ceph_cap, ci_node);
- if (__cap_is_valid(cap) &&
- (cap->implemented & ~cap->issued & mask)) {
- ret = 1;
- break;
- }
- }
+ ret = __ceph_caps_revoking_other(ci, NULL, mask);
spin_unlock(&ci->i_ceph_lock);
dout("ceph_caps_revoking %p %s = %d\n", inode,
ceph_cap_string(mask), ret);
@@ -2488,6 +2494,11 @@
} else {
dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
ceph_cap_string(newcaps));
+ /* non-auth MDS is revoking the newly grant caps ? */
+ if (cap == ci->i_auth_cap &&
+ __ceph_caps_revoking_other(ci, cap, newcaps))
+ check_caps = 2;
+
cap->issued = newcaps;
cap->implemented |= newcaps; /* add bits only, to
* avoid stepping on a