ceph: trim deleted inode

The MDS uses caps message to notify clients about deleted inode.
when receiving a such message, invalidate any alias of the inode.
This makes the kernel release the inode ASAP.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>

1 files changed, 40 insertions, 1 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 25442b40c25a..430121a795bd 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2334,6 +2334,38 @@ void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
 }
 
 /*
+ * Invalidate unlinked inode's aliases, so we can drop the inode ASAP.
+ */
+static void invalidate_aliases(struct inode *inode)
+{
+        struct dentry *dn, *prev = NULL;
+
+        dout("invalidate_aliases inode %p\n", inode);
+        d_prune_aliases(inode);
+        /*
+         * For non-directory inode, d_find_alias() only returns
+         * connected dentry. After calling d_delete(), the dentry
+         * become disconnected.
+         *
+         * For directory inode, d_find_alias() only can return
+         * disconnected dentry. But directory inode should have
+         * one alias at most.
+         */
+        while ((dn = d_find_alias(inode))) {
+                if (dn == prev) {
+                        dput(dn);
+                        break;
+                }
+                d_delete(dn);
+                if (prev)
+                        dput(prev);
+                prev = dn;
+        }
+        if (prev)
+                dput(prev);
+}
+
+/*
  * Handle a cap GRANT message from the MDS.  (Note that a GRANT may
  * actually be a revocation if it specifies a smaller cap set.)
  *
@@ -2363,6 +2395,7 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
         int writeback = 0;
         int revoked_rdcache = 0;
         int queue_invalidate = 0;
+        int deleted_inode = 0;
 
         dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
              inode, cap, mds, seq, ceph_cap_string(newcaps));
@@ -2407,8 +2440,12 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                      from_kgid(&init_user_ns, inode->i_gid));
         }
 
-        if ((issued & CEPH_CAP_LINK_EXCL) == 0)
+        if ((issued & CEPH_CAP_LINK_EXCL) == 0) {
                 set_nlink(inode, le32_to_cpu(grant->nlink));
+                if (inode->i_nlink == 0 &&
+                    (newcaps & (CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL)))
+                        deleted_inode = 1;
+        }
 
         if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
                 int len = le32_to_cpu(grant->xattr_len);
@@ -2517,6 +2554,8 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
                 ceph_queue_writeback(inode);
         if (queue_invalidate)
                 ceph_queue_invalidate(inode);
+        if (deleted_inode)
+                invalidate_aliases(inode);
         if (wake)
                 wake_up_all(&ci->i_cap_wq);