staging: lustre: lov: add cl_object_layout_get()

Add cl_object_layout_get() to return the layout and generation of an
object. Replace some direct accesses to object LSM with calls to this
function.

In ll_getxattr() factor out the LOV xattr specific handling into a new
function ll_getxattr_lov() which calls cl_object_layout_get(). In
ll_listxattr() call ll_getxattr_lov() to determine if a lustre.lov
xattr should be emitted.  Add lov_lsm_pack() to generate LOV xattrs
from a LSM.

Remove the unused functions ccc_inode_lsm_{get,put}() and
lov_lsm_get().

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5814
Reviewed-on: http://review.whamcloud.com/13680
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 90 insertions, 62 deletions

diff --git a/drivers/staging/lustre/lustre/lov/lov_internal.h b/drivers/staging/lustre/lustre/lov/lov_internal.h
index fffc18ccd97e..60397a28ef58 100644
--- a/drivers/staging/lustre/lustre/lov/lov_internal.h
+++ b/drivers/staging/lustre/lustre/lov/lov_internal.h
@@ -176,6 +176,8 @@ int lov_del_target(struct obd_device *obd, __u32 index,
 		   struct obd_uuid *uuidp, int gen);
 
 /* lov_pack.c */
+ssize_t lov_lsm_pack(const struct lov_stripe_md *lsm, void *buf,
+		     size_t buf_size);
 int lov_packmd(struct obd_export *exp, struct lov_mds_md **lmm,
 	       struct lov_stripe_md *lsm);
 int lov_unpackmd(struct obd_export *exp, struct lov_stripe_md **lsmp,
diff --git a/drivers/staging/lustre/lustre/lov/lov_object.c b/drivers/staging/lustre/lustre/lov/lov_object.c
index 07bef44c7439..d39724ac0fd1 100644
--- a/drivers/staging/lustre/lustre/lov/lov_object.c
+++ b/drivers/staging/lustre/lustre/lov/lov_object.c
@@ -75,12 +75,11 @@ struct lov_layout_operations {
 
 static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov);
 
-void lov_lsm_put(struct cl_object *unused, struct lov_stripe_md *lsm)
+static void lov_lsm_put(struct lov_stripe_md *lsm)
 {
 	if (lsm)
 		lov_free_memmd(&lsm);
 }
-EXPORT_SYMBOL(lov_lsm_put);
 
 /*****************************************************************************
  *
@@ -1408,7 +1407,7 @@ obj_put:
 		cl_object_put(env, subobj);
 out:
 	kvfree(fm_local);
-	lov_lsm_put(obj, lsm);
+	lov_lsm_put(lsm);
 	return rc;
 }
 
@@ -1424,10 +1423,37 @@ static int lov_object_getstripe(const struct lu_env *env, struct cl_object *obj,
 		return -ENODATA;
 
 	rc = lov_getstripe(cl2lov(obj), lsm, lum);
-	lov_lsm_put(obj, lsm);
+	lov_lsm_put(lsm);
 	return rc;
 }
 
+static int lov_object_layout_get(const struct lu_env *env,
+				 struct cl_object *obj,
+				 struct cl_layout *cl)
+{
+	struct lov_object *lov = cl2lov(obj);
+	struct lov_stripe_md *lsm = lov_lsm_addref(lov);
+	struct lu_buf *buf = &cl->cl_buf;
+	ssize_t rc;
+
+	if (!lsm) {
+		cl->cl_size = 0;
+		cl->cl_layout_gen = CL_LAYOUT_GEN_EMPTY;
+		cl->cl_is_released = false;
+
+		return 0;
+	}
+
+	cl->cl_size = lov_mds_md_size(lsm->lsm_stripe_count, lsm->lsm_magic);
+	cl->cl_layout_gen = lsm->lsm_layout_gen;
+	cl->cl_is_released = lsm_is_released(lsm);
+
+	rc = lov_lsm_pack(lsm, buf->lb_buf, buf->lb_len);
+	lov_lsm_put(lsm);
+
+	return rc < 0 ? rc : 0;
+}
+
 static const struct cl_object_operations lov_ops = {
 	.coo_page_init = lov_page_init,
 	.coo_lock_init = lov_lock_init,
@@ -1436,6 +1462,7 @@ static const struct cl_object_operations lov_ops = {
 	.coo_attr_update = lov_attr_update,
 	.coo_conf_set  = lov_conf_set,
 	.coo_getstripe = lov_object_getstripe,
+	.coo_layout_get	 = lov_object_layout_get,
 	.coo_fiemap	 = lov_object_fiemap,
 };
 
@@ -1488,22 +1515,6 @@ struct lov_stripe_md *lov_lsm_addref(struct lov_object *lov)
 	return lsm;
 }
 
-struct lov_stripe_md *lov_lsm_get(struct cl_object *clobj)
-{
-	struct lu_object *luobj;
-	struct lov_stripe_md *lsm = NULL;
-
-	if (!clobj)
-		return NULL;
-
-	luobj = lu_object_locate(&cl_object_header(clobj)->coh_lu,
-				 &lov_device_type);
-	if (luobj)
-		lsm = lov_lsm_addref(lu2lov(luobj));
-	return lsm;
-}
-EXPORT_SYMBOL(lov_lsm_get);
-
 int lov_read_and_clear_async_rc(struct cl_object *clob)
 {
 	struct lu_object *luobj;
diff --git a/drivers/staging/lustre/lustre/lov/lov_pack.c b/drivers/staging/lustre/lustre/lov/lov_pack.c
index be6e9857ce2a..1156ef986422 100644
--- a/drivers/staging/lustre/lustre/lov/lov_pack.c
+++ b/drivers/staging/lustre/lustre/lov/lov_pack.c
@@ -97,6 +97,62 @@ void lov_dump_lmm_v3(int level, struct lov_mds_md_v3 *lmm)
 			     le16_to_cpu(lmm->lmm_stripe_count));
 }
 
+/**
+ * Pack LOV striping metadata for disk storage format (in little
+ * endian byte order).
+ *
+ * This follows the getxattr() conventions. If \a buf_size is zero
+ * then return the size needed. If \a buf_size is too small then
+ * return -ERANGE. Otherwise return the size of the result.
+ */
+ssize_t lov_lsm_pack(const struct lov_stripe_md *lsm, void *buf,
+		     size_t buf_size)
+{
+	struct lov_ost_data_v1 *lmm_objects;
+	struct lov_mds_md_v1 *lmmv1 = buf;
+	struct lov_mds_md_v3 *lmmv3 = buf;
+	size_t lmm_size;
+	unsigned int i;
+
+	lmm_size = lov_mds_md_size(lsm->lsm_stripe_count, lsm->lsm_magic);
+	if (!buf_size)
+		return lmm_size;
+
+	if (buf_size < lmm_size)
+		return -ERANGE;
+
+	/*
+	 * lmmv1 and lmmv3 point to the same struct and have the
+	 * same first fields
+	 */
+	lmmv1->lmm_magic = cpu_to_le32(lsm->lsm_magic);
+	lmm_oi_cpu_to_le(&lmmv1->lmm_oi, &lsm->lsm_oi);
+	lmmv1->lmm_stripe_size = cpu_to_le32(lsm->lsm_stripe_size);
+	lmmv1->lmm_stripe_count = cpu_to_le16(lsm->lsm_stripe_count);
+	lmmv1->lmm_pattern = cpu_to_le32(lsm->lsm_pattern);
+	lmmv1->lmm_layout_gen = cpu_to_le16(lsm->lsm_layout_gen);
+
+	if (lsm->lsm_magic == LOV_MAGIC_V3) {
+		CLASSERT(sizeof(lsm->lsm_pool_name) ==
+			 sizeof(lmmv3->lmm_pool_name));
+		strlcpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
+			sizeof(lmmv3->lmm_pool_name));
+		lmm_objects = lmmv3->lmm_objects;
+	} else {
+		lmm_objects = lmmv1->lmm_objects;
+	}
+
+	for (i = 0; i < lsm->lsm_stripe_count; i++) {
+		struct lov_oinfo *loi = lsm->lsm_oinfo[i];
+
+		ostid_cpu_to_le(&loi->loi_oi, &lmm_objects[i].l_ost_oi);
+		lmm_objects[i].l_ost_gen = cpu_to_le32(loi->loi_ost_gen);
+		lmm_objects[i].l_ost_idx = cpu_to_le32(loi->loi_ost_idx);
+	}
+
+	return lmm_size;
+}
+
 /* Pack LOV object metadata for disk storage.  It is packed in LE byte
  * order and is opaque to the networking layer.
  *
@@ -108,13 +164,8 @@ void lov_dump_lmm_v3(int level, struct lov_mds_md_v3 *lmm)
 int lov_obd_packmd(struct lov_obd *lov, struct lov_mds_md **lmmp,
 		   struct lov_stripe_md *lsm)
 {
-	struct lov_mds_md_v1 *lmmv1;
-	struct lov_mds_md_v3 *lmmv3;
 	__u16 stripe_count;
-	struct lov_ost_data_v1 *lmm_objects;
 	int lmm_size, lmm_magic;
-	int i;
-	int cplen = 0;
 
 	if (lsm) {
 		lmm_magic = lsm->lsm_magic;
@@ -177,46 +228,10 @@ int lov_obd_packmd(struct lov_obd *lov, struct lov_mds_md **lmmp,
 	CDEBUG(D_INFO, "lov_packmd: LOV_MAGIC 0x%08X, lmm_size = %d\n",
 	       lmm_magic, lmm_size);
 
-	lmmv1 = *lmmp;
-	lmmv3 = (struct lov_mds_md_v3 *)*lmmp;
-	if (lmm_magic == LOV_MAGIC_V3)
-		lmmv3->lmm_magic = cpu_to_le32(LOV_MAGIC_V3);
-	else
-		lmmv1->lmm_magic = cpu_to_le32(LOV_MAGIC_V1);
-
 	if (!lsm)
 		return lmm_size;
 
-	/* lmmv1 and lmmv3 point to the same struct and have the
-	 * same first fields
-	 */
-	lmm_oi_cpu_to_le(&lmmv1->lmm_oi, &lsm->lsm_oi);
-	lmmv1->lmm_stripe_size = cpu_to_le32(lsm->lsm_stripe_size);
-	lmmv1->lmm_stripe_count = cpu_to_le16(stripe_count);
-	lmmv1->lmm_pattern = cpu_to_le32(lsm->lsm_pattern);
-	lmmv1->lmm_layout_gen = cpu_to_le16(lsm->lsm_layout_gen);
-	if (lsm->lsm_magic == LOV_MAGIC_V3) {
-		cplen = strlcpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
-				sizeof(lmmv3->lmm_pool_name));
-		if (cplen >= sizeof(lmmv3->lmm_pool_name))
-			return -E2BIG;
-		lmm_objects = lmmv3->lmm_objects;
-	} else {
-		lmm_objects = lmmv1->lmm_objects;
-	}
-
-	for (i = 0; i < stripe_count; i++) {
-		struct lov_oinfo *loi = lsm->lsm_oinfo[i];
-		/* XXX LOV STACKING call down to osc_packmd() to do packing */
-		LASSERTF(ostid_id(&loi->loi_oi) != 0, "lmm_oi "DOSTID
-			 " stripe %u/%u idx %u\n", POSTID(&lmmv1->lmm_oi),
-			 i, stripe_count, loi->loi_ost_idx);
-		ostid_cpu_to_le(&loi->loi_oi, &lmm_objects[i].l_ost_oi);
-		lmm_objects[i].l_ost_gen = cpu_to_le32(loi->loi_ost_gen);
-		lmm_objects[i].l_ost_idx = cpu_to_le32(loi->loi_ost_idx);
-	}
-
-	return lmm_size;
+	return lov_lsm_pack(lsm, *lmmp, lmm_size);
 }
 
 int lov_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,