nfsd: fix jiffies/time_t mixup in LRU list

commit 9594497f2c78993cb66b696122f7c65528ace985 upstream.

The nfsd4_blocked_lock->nbl_time timestamp is recorded in jiffies,
but then compared to a CLOCK_REALTIME timestamp later on, which makes
no sense.

For consistency with the other timestamps, change this to use a time_t.

This is a change in behavior, which may cause regressions, but the
current code is not sensible. On a system with CONFIG_HZ=1000,
the 'time_after((unsigned long)nbl->nbl_time, (unsigned long)cutoff))'
check is false for roughly the first 18 days of uptime and then true
for the next 49 days.

Fixes: 7919d0a27f1e ("nfsd: add a LRU list for blocked locks")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 08f6eb2..1c82d7d 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -6550,7 +6550,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        }
 
        if (fl_flags & FL_SLEEP) {
        }
 
        if (fl_flags & FL_SLEEP) {

-               nbl->nbl_time = jiffies;
+               nbl->nbl_time = get_seconds();

                spin_lock(&nn->blocked_locks_lock);
                list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked);
                list_add_tail(&nbl->nbl_lru, &nn->blocked_locks_lru);
                spin_lock(&nn->blocked_locks_lock);
                list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked);
                list_add_tail(&nbl->nbl_lru, &nn->blocked_locks_lru);

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 46f56af..a080789 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -605,7 +605,7 @@ static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
 struct nfsd4_blocked_lock {
        struct list_head        nbl_list;
        struct list_head        nbl_lru;
 struct nfsd4_blocked_lock {
        struct list_head        nbl_list;
        struct list_head        nbl_lru;

-       unsigned long           nbl_time;
+       time_t                  nbl_time;

        struct file_lock        nbl_lock;
        struct knfsd_fh         nbl_fh;
        struct nfsd4_callback   nbl_cb;
        struct file_lock        nbl_lock;
        struct knfsd_fh         nbl_fh;
        struct nfsd4_callback   nbl_cb;