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| author |  Andrew Price <anprice@redhat.com>
| 2017-02-22 12:05:03 -0500 |
|---|---|---|
| committer |  Bob Peterson <rpeterso@redhat.com>
| 2017-02-23 10:06:00 -0500 |
| commit | f38e5fb95a1f8feda88531eedc98f69b24748712 (patch) | |
| tree | 941eb63a04a4ce71733273d1db846d501bfccf22 | |
| parent | gfs2: Make gfs2_write_full_page static (diff) | |
| download | linux-f38e5fb95a1f8feda88531eedc98f69b24748712.tar.gz linux-f38e5fb95a1f8feda88531eedc98f69b24748712.tar.bz2 linux-f38e5fb95a1f8feda88531eedc98f69b24748712.zip | |
gfs2: Add missing rcu locking for glock lookup
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.
Cc: <stable@vger.kernel.org> # 4.3+
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
| -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 2928f1209b67..d004debe2856 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -658,9 +658,11 @@ 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) @@ -728,15 +730,18 @@ 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); } |