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| author | Andrew Price <anprice@redhat.com> | 2017-02-22 20:05:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-12 08:37:29 +0300 |
| commit | 70a09029b7be8091499aef3ed39a91325d841ec4 (patch) | |
| tree | 12fb13056d48fb9088456e81903c41b1a21ddb35 | |
| parent | 44dd30e04c1f59dff7115857e51bce4b6ddd2137 (diff) | |
| download | linux-70a09029b7be8091499aef3ed39a91325d841ec4.tar.xz | |
gfs2: Add missing rcu locking for glock lookup
commit f38e5fb95a1f8feda88531eedc98f69b24748712 upstream.
We must hold the rcu read lock across looking up glocks and trying to
bump their refcount to prevent the glocks from being freed in between.
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/gfs2/glock.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 32e74710b1aa..9cd8c92b953d 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -651,9 +651,11 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, struct kmem_cache *cachep; int ret, tries = 0; + rcu_read_lock(); gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); if (gl && !lockref_get_not_dead(&gl->gl_lockref)) gl = NULL; + rcu_read_unlock(); *glp = gl; if (gl) @@ -721,15 +723,18 @@ again: if (ret == -EEXIST) { ret = 0; + rcu_read_lock(); tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) { if (++tries < 100) { + rcu_read_unlock(); cond_resched(); goto again; } tmp = NULL; ret = -ENOMEM; } + rcu_read_unlock(); } else { WARN_ON_ONCE(ret); } |