nfsd: set and test NFSD4_CLIENT_STABLE bit to reduce nfsdcltrack upcalls

The nfsdcltrack upcall doesn't utilize the NFSD4_CLIENT_STABLE flag,
which basically results in an upcall every time we call into the client
tracking ops.

Change it to set this bit on a successful "check" or "create" request,
and clear it on a "remove" request.  Also, check to see if that bit is
set before upcalling on a "check" or "remove" request, and skip
upcalling appropriately, depending on its state.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index bf3a3575d060..d0fc003d130a 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -1296,7 +1296,8 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
         grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
 
         nfsd4_cltrack_upcall_lock(clp);
-        nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start);
+        if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
+                set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
         nfsd4_cltrack_upcall_unlock(clp);
 
         kfree(has_session);
@@ -1309,6 +1310,9 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
 {
         char *hexid;
 
+        if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+                return;
+
         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
         if (!hexid) {
                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
@@ -1316,7 +1320,9 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
         }
 
         nfsd4_cltrack_upcall_lock(clp);
-        nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL);
+        if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
+            nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
+                clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
         nfsd4_cltrack_upcall_unlock(clp);
 
         kfree(hexid);
@@ -1328,6 +1334,9 @@ nfsd4_umh_cltrack_check(struct nfs4_client *clp)
         int ret;
         char *hexid, *has_session, *legacy;
 
+        if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+                return 0;
+
         hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
         if (!hexid) {
                 dprintk("%s: can't allocate memory for upcall!\n", __func__);
@@ -1338,9 +1347,14 @@ nfsd4_umh_cltrack_check(struct nfs4_client *clp)
         legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
 
         nfsd4_cltrack_upcall_lock(clp);
-        ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
+        if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
+                ret = 0;
+        } else {
+                ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
+                if (ret == 0)
+                        set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+        }
         nfsd4_cltrack_upcall_unlock(clp);
-
         kfree(has_session);
         kfree(legacy);
         kfree(hexid);