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authorAndreas Gruenbacher <agruenba@redhat.com>2017-03-16 09:54:57 -0400
committerBob Peterson <rpeterso@redhat.com>2017-03-16 09:58:49 -0400
commit972b044eeca582ef173d063773e292bd9e8633d6 (patch)
tree96ce685382befb17ba33751851cebde074f1a1a1
parent92ecd73a887c4a2b94daf5fc35179d75d1c4ef95 (diff)
downloadop-kernel-dev-972b044eeca582ef173d063773e292bd9e8633d6.zip
op-kernel-dev-972b044eeca582ef173d063773e292bd9e8633d6.tar.gz
gfs2: Don't pack struct lm_lockname
As per a suggestion by Linus, don't pack struct lm_lockname: we did that because the struct is used as a rhashtable key, but packing tells the compiler that the 64-bit fields in the struct may be unaligned, causing it to generate worse code on some architectures. Instead, rearrange the fields in the struct so that there is no padding between fields, and exclude any tail padding from the hash key size. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
-rw-r--r--fs/gfs2/glock.c2
-rw-r--r--fs/gfs2/incore.h8
2 files changed, 7 insertions, 3 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index b2638d8..35f3b0a 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -73,7 +73,7 @@ static DEFINE_SPINLOCK(lru_lock);
static struct rhashtable_params ht_parms = {
.nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4,
- .key_len = sizeof(struct lm_lockname),
+ .key_len = offsetofend(struct lm_lockname, ln_type),
.key_offset = offsetof(struct gfs2_glock, gl_name),
.head_offset = offsetof(struct gfs2_glock, gl_node),
};
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 511e1ed..b7cf65d 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -203,11 +203,15 @@ enum {
DFL_DLM_RECOVERY = 6,
};
+/*
+ * We are using struct lm_lockname as an rhashtable key. Avoid holes within
+ * the struct; padding at the end is fine.
+ */
struct lm_lockname {
- struct gfs2_sbd *ln_sbd;
u64 ln_number;
+ struct gfs2_sbd *ln_sbd;
unsigned int ln_type;
-} __packed __aligned(sizeof(int));
+};
#define lm_name_equal(name1, name2) \
(((name1)->ln_number == (name2)->ln_number) && \
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