ceph: flush dirty caps of unlinked inode ASAP

Client should release unlinked inode from its cache ASAP. But client
can't release inode with dirty caps.

Link: http://tracker.ceph.com/issues/22886
Signed-off-by: Zhi Zhang <zhang.david2011@gmail.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

3 files changed, 32 insertions, 24 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6582c4507e6c..0e5bd3e3344e 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3965,6 +3965,32 @@ void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
 }
 
 /*
+ * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps. If it
+ * looks like the link count will hit 0, drop any other caps (other
+ * than PIN) we don't specifically want (due to the file still being
+ * open).
+ */
+int ceph_drop_caps_for_unlink(struct inode *inode)
+{
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+
+        spin_lock(&ci->i_ceph_lock);
+        if (inode->i_nlink == 1) {
+                drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
+
+                ci->i_ceph_flags |= CEPH_I_NODELAY;
+                if (__ceph_caps_dirty(ci)) {
+                        struct ceph_mds_client *mdsc =
+                                ceph_inode_to_client(inode)->mdsc;
+                        __cap_delay_requeue_front(mdsc, ci);
+                }
+        }
+        spin_unlock(&ci->i_ceph_lock);
+        return drop;
+}
+
+/*
  * Helpers for embedding cap and dentry lease releases into mds
  * requests.
  *
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 0c4346806e17..f1d9c6cc0491 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1003,26 +1003,6 @@ static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 }
 
 /*
- * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
- * looks like the link count will hit 0, drop any other caps (other
- * than PIN) we don't specifically want (due to the file still being
- * open).
- */
-static int drop_caps_for_unlink(struct inode *inode)
-{
-        struct ceph_inode_info *ci = ceph_inode(inode);
-        int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
-
-        spin_lock(&ci->i_ceph_lock);
-        if (inode->i_nlink == 1) {
-                drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
-                ci->i_ceph_flags |= CEPH_I_NODELAY;
-        }
-        spin_unlock(&ci->i_ceph_lock);
-        return drop;
-}
-
-/*
  * rmdir and unlink are differ only by the metadata op code
  */
 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
@@ -1056,7 +1036,7 @@ static int ceph_unlink(struct inode *dir, struct dentry *dentry)
         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
-        req->r_inode_drop = drop_caps_for_unlink(inode);
+        req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
         err = ceph_mdsc_do_request(mdsc, dir, req);
         if (!err && !req->r_reply_info.head->is_dentry)
                 d_delete(dentry);
@@ -1104,8 +1084,10 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
         /* release LINK_RDCACHE on source inode (mds will lock it) */
         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
-        if (d_really_is_positive(new_dentry))
-                req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
+        if (d_really_is_positive(new_dentry)) {
+                req->r_inode_drop =
+                        ceph_drop_caps_for_unlink(d_inode(new_dentry));
+        }
         err = ceph_mdsc_do_request(mdsc, old_dir, req);
         if (!err && !req->r_reply_info.head->is_dentry) {
                 /*
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 21b2e5b004eb..1c2086e0fec2 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -987,7 +987,7 @@ extern void ceph_check_caps(struct ceph_inode_info *ci, int flags,
                             struct ceph_mds_session *session);
 extern void ceph_check_delayed_caps(struct ceph_mds_client *mdsc);
 extern void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc);
-
+extern int  ceph_drop_caps_for_unlink(struct inode *inode);
 extern int ceph_encode_inode_release(void **p, struct inode *inode,
                                      int mds, int drop, int unless, int force);
 extern int ceph_encode_dentry_release(void **p, struct dentry *dn,