A SETCLIENTID boot verifier is nothing more than the client's boot
timestamp. An NFSv4 server is obligated to wipe all NFSv4 state for
an NFS client when the client presents an updated SETCLIENTID boot
verifier. This is how servers detect client reboots.
nfs4_reset_all_state() refreshes our client's boot verifier to trigger
a server to wipe this client's state. This function is invoked when
an NFSv4.1 server reports that it has revoked some or all of a
client's NFSv4 state.
Soon we want to get rid of the per-nfs_client cl_boot_time field,
however. Without cl_boot_time, our NFS client will need to find a
different way to force the server to purge the client's NFSv4 state.
Because these verifiers are opaque (ie, the server doesn't know or
care that they happen to be timestamps), we can do force the server
to wipe NFSv4 state by using the same trick we use now, but then
immediately afterwards establish a fresh client ID using the old boot
verifier again.
Hopefully there are no extra paranoid server implementations that keep
track of the client's boot verifiers and prevent clients from reusing
a previous one.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/nfs4_fs.h | 1 +
fs/nfs/nfs4proc.c | 9 +++++++--
fs/nfs/nfs4state.c | 13 +++++++++++--
3 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 03d3ff0..f164c73 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -24,6 +24,7 @@ enum nfs4_client_state {
NFS4CLNT_RECALL_SLOT,
NFS4CLNT_LEASE_CONFIRM,
NFS4CLNT_SERVER_SCOPE_MISMATCH,
+ NFS4CLNT_PURGE_STATE,
};
enum nfs4_session_state {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 73cfd9e..c56d547 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3937,8 +3937,13 @@ static void nfs4_construct_boot_verifier(struct nfs_client *clp,
{
__be32 verf[2];
- verf[0] = (__be32)clp->cl_boot_time.tv_sec;
- verf[1] = (__be32)clp->cl_boot_time.tv_nsec;
+ if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
+ verf[0] = (__be32)CURRENT_TIME.tv_sec;
+ verf[1] = (__be32)CURRENT_TIME.tv_nsec;
+ } else {
+ verf[0] = (__be32)clp->cl_boot_time.tv_sec;
+ verf[1] = (__be32)clp->cl_boot_time.tv_nsec;
+ }
memcpy(bootverf->data, verf, sizeof(bootverf->data));
}
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index f8c06de..32cce4a 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1615,7 +1615,7 @@ void nfs41_handle_recall_slot(struct nfs_client *clp)
static void nfs4_reset_all_state(struct nfs_client *clp)
{
if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
- clp->cl_boot_time = CURRENT_TIME;
+ set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
nfs4_state_start_reclaim_nograce(clp);
nfs4_schedule_state_manager(clp);
}
@@ -1631,7 +1631,6 @@ static void nfs41_handle_server_reboot(struct nfs_client *clp)
static void nfs41_handle_state_revoked(struct nfs_client *clp)
{
- /* Temporary */
nfs4_reset_all_state(clp);
}
@@ -1652,6 +1651,10 @@ void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
{
if (!flags)
return;
+
+ dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
+ __func__, clp->cl_hostname, clp->cl_clientid, flags);
+
if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
nfs41_handle_server_reboot(clp);
if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
@@ -1762,6 +1765,12 @@ static void nfs4_state_manager(struct nfs_client *clp)
/* Ensure exclusive access to NFSv4 state */
do {
+ if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
+ nfs4_reclaim_lease(clp);
+ clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
+ set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+ }
+
if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
/* We're going to have to re-establish a clientid */
status = nfs4_reclaim_lease(clp);
--
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