From 6a25478077d987edc5e2f880590a2bc5fcab4441 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 11 Feb 2017 19:26:45 +0800 Subject: [PATCH] gfs2: Use rhashtable walk interface in glock_hash_walk The function glock_hash_walk walks the rhashtable by hand. This is broken because if it catches the hash table in the middle of a rehash, then it will miss entries. This patch replaces the manual walk by using the rhashtable walk interface. Fixes: 88ffbf3e037e ("GFS2: Use resizable hash table for glocks") Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- fs/gfs2/glock.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 94f50cac91c6..70e94170af85 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1420,26 +1420,32 @@ static struct shrinker glock_shrinker = { * @sdp: the filesystem * @bucket: the bucket * + * Note that the function can be called multiple times on the same + * object. So the user must ensure that the function can cope with + * that. */ static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) { struct gfs2_glock *gl; - struct rhash_head *pos; - const struct bucket_table *tbl; - int i; + struct rhashtable_iter iter; - rcu_read_lock(); - tbl = rht_dereference_rcu(gl_hash_table.tbl, &gl_hash_table); - for (i = 0; i < tbl->size; i++) { - rht_for_each_entry_rcu(gl, pos, tbl, i, gl_node) { + rhashtable_walk_enter(&gl_hash_table, &iter); + + do { + gl = ERR_PTR(rhashtable_walk_start(&iter)); + if (gl) + continue; + + while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl)) if ((gl->gl_name.ln_sbd == sdp) && lockref_get_not_dead(&gl->gl_lockref)) examiner(gl); - } - } - rcu_read_unlock(); - cond_resched(); + + rhashtable_walk_stop(&iter); + } while (cond_resched(), gl == ERR_PTR(-EAGAIN)); + + rhashtable_walk_exit(&iter); } /**