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authorAhmed S. Darwish <a.darwish@linutronix.de>2020-07-20 18:55:27 +0300
committerPeter Zijlstra <peterz@infradead.org>2020-07-29 17:14:28 +0300
commit76246c9219726c71e3f470344d8c6a566fa2535b (patch)
tree7d5c228875a676e7acc2c813f1d34d1535c144cb /fs/nfs
parent67b7b641ca69cafb467f7560316b09b8ff0fa5c9 (diff)
downloadlinux-76246c9219726c71e3f470344d8c6a566fa2535b.tar.xz
NFSv4: Use sequence counter with associated spinlock
A sequence counter write side critical section must be protected by some form of locking to serialize writers. A plain seqcount_t does not contain the information of which lock must be held when entering a write side critical section. Use the new seqcount_spinlock_t data type, which allows to associate a spinlock with the sequence counter. This enables lockdep to verify that the spinlock used for writer serialization is held when the write side critical section is entered. If lockdep is disabled this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200720155530.1173732-22-a.darwish@linutronix.de
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4_fs.h2
-rw-r--r--fs/nfs/nfs4state.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 2b7f6dcd2eb8..210e590e1f71 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -117,7 +117,7 @@ struct nfs4_state_owner {
unsigned long so_flags;
struct list_head so_states;
struct nfs_seqid_counter so_seqid;
- seqcount_t so_reclaim_seqcount;
+ seqcount_spinlock_t so_reclaim_seqcount;
struct mutex so_delegreturn_mutex;
};
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index a8dc25ce48bb..b1dba24918f8 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -509,7 +509,7 @@ nfs4_alloc_state_owner(struct nfs_server *server,
nfs4_init_seqid_counter(&sp->so_seqid);
atomic_set(&sp->so_count, 1);
INIT_LIST_HEAD(&sp->so_lru);
- seqcount_init(&sp->so_reclaim_seqcount);
+ seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
mutex_init(&sp->so_delegreturn_mutex);
return sp;
}