/**
* Create a memory descriptor and attach it to a ME
*
* \param meh A handle for a ME to associate the new MD with.
* \param umd Provides initial values for the user-visible parts of a MD.
* Other than its use for initialization, there is no linkage between this
* structure and the MD maintained by the LNet.
* \param unlink A flag to indicate whether the MD is automatically unlinked
* when it becomes inactive, either because the operation threshold drops to
* zero or because the available memory becomes less than \a umd.max_size.
* (Note that the check for unlinking a MD only occurs after the completion
* of a successful operation on the MD.) The value LNET_UNLINK enables auto
* unlinking; the value LNET_RETAIN disables it.
* \param handle On successful returns, a handle to the newly created MD is
* saved here. This handle can be used later in LNetMDUnlink().
*
* \retval 0 On success.
* \retval -EINVAL If \a umd is not valid.
* \retval -ENOMEM If new MD cannot be allocated.
* \retval -ENOENT Either \a meh or \a umd.eq_handle does not point to a
* valid object. Note that it's OK to supply a NULL \a umd.eq_handle by
* calling LNetInvalidateHandle() on it.
* \retval -EBUSY If the ME pointed to by \a meh is already associated with
* a MD.
*/
int
LNetMDAttach(lnet_handle_me_t meh, lnet_md_t umd,
lnet_unlink_t unlink, lnet_handle_md_t *handle)
{
CFS_LIST_HEAD (matches);
CFS_LIST_HEAD (drops);
struct lnet_me *me;
struct lnet_libmd *md;
int cpt;
int rc;
LASSERT (the_lnet.ln_init);
LASSERT (the_lnet.ln_refcount > 0);
if (lnet_md_validate(&umd) != 0)
return -EINVAL;
if ((umd.options & (LNET_MD_OP_GET | LNET_MD_OP_PUT)) == 0) {
CERROR("Invalid option: no MD_OP set\n");
return -EINVAL;
}
md = lnet_md_alloc(&umd);
if (md == NULL)
return -ENOMEM;
rc = lnet_md_build(md, &umd, unlink);
cpt = lnet_cpt_of_cookie(meh.cookie);
lnet_res_lock(cpt);
if (rc != 0)
goto failed;
me = lnet_handle2me(&meh);
if (me == NULL)
rc = -ENOENT;
else if (me->me_md != NULL)
rc = -EBUSY;
else
rc = lnet_md_link(md, umd.eq_handle, cpt);
if (rc != 0)
goto failed;
/* attach this MD to portal of ME and check if it matches any
* blocked msgs on this portal */
lnet_ptl_attach_md(me, md, &matches, &drops);
lnet_md2handle(handle, md);
lnet_res_unlock(cpt);
lnet_drop_delayed_msg_list(&drops, "Bad match");
lnet_recv_delayed_msg_list(&matches);
return 0;
failed:
lnet_md_free_locked(md);
lnet_res_unlock(cpt);
return rc;
}
/**
* Create a memory descriptor and attach it to a ME
*
* \param meh A handle for a ME to associate the new MD with.
* \param umd Provides initial values for the user-visible parts of a MD.
* Other than its use for initialization, there is no linkage between this
* structure and the MD maintained by the LNet.
* \param unlink A flag to indicate whether the MD is automatically unlinked
* when it becomes inactive, either because the operation threshold drops to
* zero or because the available memory becomes less than \a umd.max_size.
* (Note that the check for unlinking a MD only occurs after the completion
* of a successful operation on the MD.) The value LNET_UNLINK enables auto
* unlinking; the value LNET_RETAIN disables it.
* \param handle On successful returns, a handle to the newly created MD is
* saved here. This handle can be used later in LNetMDUnlink().
*
* \retval 0 On success.
* \retval -EINVAL If \a umd is not valid.
* \retval -ENOMEM If new MD cannot be allocated.
* \retval -ENOENT Either \a meh or \a umd.eq_handle does not point to a
* valid object. Note that it's OK to supply a NULL \a umd.eq_handle by
* calling LNetInvalidateHandle() on it.
* \retval -EBUSY If the ME pointed to by \a meh is already associated with
* a MD.
*/
int
LNetMDAttach(struct lnet_handle_me meh, struct lnet_md umd,
enum lnet_unlink unlink, struct lnet_handle_md *handle)
{
LIST_HEAD(matches);
LIST_HEAD(drops);
struct lnet_me *me;
struct lnet_libmd *md;
int cpt;
int rc;
LASSERT(the_lnet.ln_refcount > 0);
if (lnet_md_validate(&umd))
return -EINVAL;
if (!(umd.options & (LNET_MD_OP_GET | LNET_MD_OP_PUT))) {
CERROR("Invalid option: no MD_OP set\n");
return -EINVAL;
}
md = lnet_md_alloc(&umd);
if (!md)
return -ENOMEM;
rc = lnet_md_build(md, &umd, unlink);
if (rc)
goto out_free;
cpt = lnet_cpt_of_cookie(meh.cookie);
lnet_res_lock(cpt);
me = lnet_handle2me(&meh);
if (!me)
rc = -ENOENT;
else if (me->me_md)
rc = -EBUSY;
else
rc = lnet_md_link(md, umd.eq_handle, cpt);
if (rc)
goto out_unlock;
/*
* attach this MD to portal of ME and check if it matches any
* blocked msgs on this portal
*/
lnet_ptl_attach_md(me, md, &matches, &drops);
lnet_md2handle(handle, md);
lnet_res_unlock(cpt);
lnet_drop_delayed_msg_list(&drops, "Bad match");
lnet_recv_delayed_msg_list(&matches);
return 0;
out_unlock:
lnet_res_unlock(cpt);
out_free:
lnet_md_free(md);
return rc;
}