ceph: remove the capsnaps when removing caps

[ Upstream commit a6d37ccdd240e80f26aaea0e62cda310e0e184d7 ]

capsnaps will take inode references via ihold when queueing to flush.
When force unmounting, the client will just close the sessions and
may never get a flush reply, causing a leak and inode ref leak.

Fix this by removing the capsnaps for an inode when removing the caps.

URL: https://tracker.ceph.com/issues/52295
Signed-off-by: Xiubo Li <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>

fs/ceph/caps.c

@@ -3169,7 +3169,16 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
  break;
  }
  }
- BUG_ON(!found);
+
+ if (!found) {
+ /*
+ * The capsnap should already be removed when removing
+ * auth cap in the case of a forced unmount.
+ */
+ WARN_ON_ONCE(ci->i_auth_cap);
+ goto unlock;
+ }
+
  capsnap->dirty_pages -= nr;
  if (capsnap->dirty_pages == 0) {
  complete_capsnap = true;
@@ -3191,6 +3200,7 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
  complete_capsnap ? " (complete capsnap)" : "");
  }
 
+unlock:
  spin_unlock(&ci->i_ceph_lock);
 
  if (last) {
@@ -3657,6 +3667,43 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
  iput(inode);
 }
 
+void __ceph_remove_capsnap(struct inode *inode, struct ceph_cap_snap *capsnap,
+ bool *wake_ci, bool *wake_mdsc)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
+ bool ret;
+
+ lockdep_assert_held(&ci->i_ceph_lock);
+
+ dout("removing capsnap %p, inode %p ci %p\n", capsnap, inode, ci);
+
+ list_del_init(&capsnap->ci_item);
+ ret = __detach_cap_flush_from_ci(ci, &capsnap->cap_flush);
+ if (wake_ci)
+ *wake_ci = ret;
+
+ spin_lock(&mdsc->cap_dirty_lock);
+ if (list_empty(&ci->i_cap_flush_list))
+ list_del_init(&ci->i_flushing_item);
+
+ ret = __detach_cap_flush_from_mdsc(mdsc, &capsnap->cap_flush);
+ if (wake_mdsc)
+ *wake_mdsc = ret;
+ spin_unlock(&mdsc->cap_dirty_lock);
+}
+
+void ceph_remove_capsnap(struct inode *inode, struct ceph_cap_snap *capsnap,
+ bool *wake_ci, bool *wake_mdsc)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+
+ lockdep_assert_held(&ci->i_ceph_lock);
+
+ WARN_ON_ONCE(capsnap->dirty_pages || capsnap->writing);
+ __ceph_remove_capsnap(inode, capsnap, wake_ci, wake_mdsc);
+}
+
 /*
  * Handle FLUSHSNAP_ACK. MDS has flushed snap data to disk and we can
  * throw away our cap_snap.
@@ -3694,23 +3741,10 @@ static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
  capsnap, capsnap->follows);
  }
  }
- if (flushed) {
- WARN_ON(capsnap->dirty_pages || capsnap->writing);
- dout(" removing %p cap_snap %p follows %lld\n",
- inode, capsnap, follows);
- list_del(&capsnap->ci_item);
- wake_ci |= __detach_cap_flush_from_ci(ci, &capsnap->cap_flush);
-
- spin_lock(&mdsc->cap_dirty_lock);
-
- if (list_empty(&ci->i_cap_flush_list))
- list_del_init(&ci->i_flushing_item);
-
- wake_mdsc |= __detach_cap_flush_from_mdsc(mdsc,
- &capsnap->cap_flush);
- spin_unlock(&mdsc->cap_dirty_lock);
- }
+ if (flushed)
+ ceph_remove_capsnap(inode, capsnap, &wake_ci, &wake_mdsc);
  spin_unlock(&ci->i_ceph_lock);
+
  if (flushed) {
  ceph_put_snap_context(capsnap->context);
  ceph_put_cap_snap(capsnap);

fs/ceph/mds_client.c

@@ -1587,22 +1587,46 @@ int ceph_iterate_session_caps(struct ceph_mds_session *session,
  return ret;
 }
 
+static int remove_capsnaps(struct ceph_mds_client *mdsc, struct inode *inode)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_cap_snap *capsnap;
+ int capsnap_release = 0;
+
+ lockdep_assert_held(&ci->i_ceph_lock);
+
+ dout("removing capsnaps, ci is %p, inode is %p\n", ci, inode);
+
+ while (!list_empty(&ci->i_cap_snaps)) {
+ capsnap = list_first_entry(&ci->i_cap_snaps,
+ struct ceph_cap_snap, ci_item);
+ __ceph_remove_capsnap(inode, capsnap, NULL, NULL);
+ ceph_put_snap_context(capsnap->context);
+ ceph_put_cap_snap(capsnap);
+ capsnap_release++;
+ }
+ wake_up_all(&ci->i_cap_wq);
+ wake_up_all(&mdsc->cap_flushing_wq);
+ return capsnap_release;
+}
+
 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
  void *arg)
 {
  struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
+ struct ceph_mds_client *mdsc = fsc->mdsc;
  struct ceph_inode_info *ci = ceph_inode(inode);
  LIST_HEAD(to_remove);
  bool dirty_dropped = false;
  bool invalidate = false;
+ int capsnap_release = 0;
 
  dout("removing cap %p, ci is %p, inode is %p\n",
  cap, ci, &ci->vfs_inode);
  spin_lock(&ci->i_ceph_lock);
  __ceph_remove_cap(cap, false);
  if (!ci->i_auth_cap) {
  struct ceph_cap_flush *cf;
- struct ceph_mds_client *mdsc = fsc->mdsc;
 
  if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
  if (inode->i_data.nrpages > 0)
@@ -1666,6 +1690,9 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
  list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
  ci->i_prealloc_cap_flush = NULL;
  }
+
+ if (!list_empty(&ci->i_cap_snaps))
+ capsnap_release = remove_capsnaps(mdsc, inode);
  }
  spin_unlock(&ci->i_ceph_lock);
  while (!list_empty(&to_remove)) {
@@ -1682,6 +1709,8 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
  ceph_queue_invalidate(inode);
  if (dirty_dropped)
  iput(inode);
+ while (capsnap_release--)
+ iput(inode);
  return 0;
 }
 

fs/ceph/super.h

@@ -1134,6 +1134,12 @@ extern void ceph_put_cap_refs_no_check_caps(struct ceph_inode_info *ci,
  int had);
 extern void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
  struct ceph_snap_context *snapc);
+extern void __ceph_remove_capsnap(struct inode *inode,
+ struct ceph_cap_snap *capsnap,
+ bool *wake_ci, bool *wake_mdsc);
+extern void ceph_remove_capsnap(struct inode *inode,
+ struct ceph_cap_snap *capsnap,
+ bool *wake_ci, bool *wake_mdsc);
 extern void ceph_flush_snaps(struct ceph_inode_info *ci,
  struct ceph_mds_session **psession);
 extern bool __ceph_should_report_size(struct ceph_inode_info *ci);