From 8dcbec6d20eb881ba368d0aebc3a8a678aebb1da Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 8 Jun 2017 11:52:44 -0400 Subject: NFSv4.1: Handle EXCHGID4_FLAG_CONFIRMED_R during NFSv4.1 migration Transparent State Migration copies a client's lease state from the server where a filesystem used to reside to the server where it now resides. When an NFSv4.1 client first contacts that destination server, it uses EXCHANGE_ID to detect trunking relationships. The lease that was copied there is returned to that client, but the destination server sets EXCHGID4_FLAG_CONFIRMED_R when replying to the client. This is because the lease was confirmed on the source server (before it was copied). Normally, when CONFIRMED_R is set, a client purges the lease and creates a new one. However, that throws away the entire benefit of Transparent State Migration. Therefore, the client must not purge that lease when it is possible that Transparent State Migration has occurred. Reported-by: Xuan Qi Signed-off-by: Chuck Lever Tested-by: Xuan Qi Signed-off-by: Anna Schumaker --- fs/nfs/nfs4client.c | 5 +++++ fs/nfs/nfs4state.c | 16 +++++++++++----- include/linux/nfs_fs_sb.h | 2 ++ 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 66776f022111..50566acb5469 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -414,6 +414,7 @@ struct nfs_client *nfs4_init_client(struct nfs_client *clp, if (clp != old) clp->cl_preserve_clid = true; nfs_put_client(clp); + clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags); return old; error: @@ -852,6 +853,8 @@ static int nfs4_set_client(struct nfs_server *server, set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags); if (server->options & NFS_OPTION_MIGRATION) set_bit(NFS_CS_MIGRATION, &cl_init.init_flags); + if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status)) + set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags); /* Allocate or find a client reference we can use */ clp = nfs_get_client(&cl_init); @@ -1212,9 +1215,11 @@ int nfs4_update_server(struct nfs_server *server, const char *hostname, return -EAFNOSUPPORT; nfs_server_remove_lists(server); + set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status); error = nfs4_set_client(server, hostname, sap, salen, buf, clp->cl_proto, clnt->cl_timeout, clp->cl_minorversion, net); + clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status); nfs_put_client(clp); if (error != 0) { nfs_server_insert_lists(server); diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index b34de036501b..83f8e60bb1e3 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -352,11 +352,17 @@ int nfs41_discover_server_trunking(struct nfs_client *clp, if (clp != *result) return 0; - /* Purge state if the client id was established in a prior instance */ - if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) - set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state); - else - set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state); + /* + * Purge state if the client id was established in a prior + * instance and the client id could not have arrived on the + * server via Transparent State Migration. + */ + if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) { + if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags)) + set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state); + else + set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state); + } nfs4_schedule_state_manager(clp); status = nfs_wait_client_init_complete(clp); if (status < 0) diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index e418a1096662..74c44665e6d3 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -42,6 +42,7 @@ struct nfs_client { #define NFS_CS_MIGRATION 2 /* - transparent state migr */ #define NFS_CS_INFINITE_SLOTS 3 /* - don't limit TCP slots */ #define NFS_CS_NO_RETRANS_TIMEOUT 4 /* - Disable retransmit timeouts */ +#define NFS_CS_TSM_POSSIBLE 5 /* - Maybe state migration */ struct sockaddr_storage cl_addr; /* server identifier */ size_t cl_addrlen; char * cl_hostname; /* hostname of server */ @@ -210,6 +211,7 @@ struct nfs_server { unsigned long mig_status; #define NFS_MIG_IN_TRANSITION (1) #define NFS_MIG_FAILED (2) +#define NFS_MIG_TSM_POSSIBLE (3) void (*destroy)(struct nfs_server *); -- cgit v1.2.3