diff options
author | Andreas Gruenbacher <agruenba@redhat.com> | 2017-02-21 23:19:10 +0100 |
---|---|---|
committer | Bob Peterson <rpeterso@redhat.com> | 2017-04-03 09:14:41 -0400 |
commit | 0a52aba7c2168636fc71635cf3ccb92a79a96c38 (patch) | |
tree | a6d611d27d4c2a91e894165e71f31488e442ccd8 /fs/gfs2 | |
parent | c369898759e0e143a513d022121290370f001d01 (diff) | |
download | linux-0a52aba7c2168636fc71635cf3ccb92a79a96c38.tar.bz2 |
gfs2: Switch to rhashtable_lookup_get_insert_fast
Switch from rhashtable_lookup_insert_fast + rhashtable_lookup_fast to
rhashtable_lookup_get_insert_fast, which is cleaner and avoids an extra
rhashtable lookup.
At the same time, turn the retry loop in gfs2_glock_get into an infinite
loop. The lookup or insert will eventually succeed, usually very fast,
but there is no reason to give up trying at a fixed number of
iterations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Diffstat (limited to 'fs/gfs2')
-rw-r--r-- | fs/gfs2/glock.c | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 35f3b0a1d81b..9e81219692c4 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -655,10 +655,10 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type, .ln_sbd = sdp }; - struct gfs2_glock *gl, *tmp = NULL; + struct gfs2_glock *gl, *tmp; struct address_space *mapping; struct kmem_cache *cachep; - int ret, tries = 0; + int ret = 0; rcu_read_lock(); gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms); @@ -723,35 +723,32 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, } again: - ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node, - ht_parms); - if (ret == 0) { + rcu_read_lock(); + tmp = rhashtable_lookup_get_insert_fast(&gl_hash_table, &gl->gl_node, + ht_parms); + if (!tmp) { *glp = gl; - return 0; + goto out; } - - 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); + if (IS_ERR(tmp)) { + ret = PTR_ERR(tmp); + goto out_free; + } + if (lockref_get_not_dead(&tmp->gl_lockref)) { + *glp = tmp; + goto out_free; } + rcu_read_unlock(); + cond_resched(); + goto again; + +out_free: kfree(gl->gl_lksb.sb_lvbptr); kmem_cache_free(cachep, gl); atomic_dec(&sdp->sd_glock_disposal); - *glp = tmp; +out: + rcu_read_unlock(); return ret; } |