*
* lustre/osp/lwp_dev.c
*
- * Light Weight Proxy, which is just for managing the connection established
- * from OSTs/MDTs to MDT0.
+ * This file provides code related to the Light Weight Proxy (LWP) managing
+ * the connections established from OST to MDT, and MDT to MDT0.
+ *
+ * A LWP connection is used to send quota and FLD query requests. It's not
+ * recoverable, which means target server doesn't have an on-disk record in
+ * the last_rcvd file to remember the connection. Once LWP reconnect after
+ * server reboot, server will always regard it as a new connection.
*
* Author: <di.wang@intel.com>
* Author: <yawei.niu@intel.com>
struct lwp_device {
struct lu_device lpd_dev;
- struct obd_device *lpd_obd;
- struct obd_uuid lpd_cluuid;
- struct obd_export *lpd_exp;
- int lpd_connects;
+ struct obd_device *lpd_obd; /* corresponding OBD device */
+ struct obd_uuid lpd_cluuid;/* UUID of LWP */
+ struct obd_export *lpd_exp; /* export of LWP */
+ int lpd_connects; /* use count, 0 or 1 */
};
static inline struct lwp_device *lu2lwp_dev(struct lu_device *d)
return &d->lpd_dev;
}
+/**
+ * Setup LWP device.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] lwp LWP device to be setup
+ * \param[in] nidstring remote target NID
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_setup(const struct lu_env *env, struct lwp_device *lwp,
char *nidstring)
{
RETURN(rc);
}
+/**
+ * Disconnect the import from LWP.
+ *
+ * \param[in] d LWP device to be disconnected
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_disconnect(struct lwp_device *d)
{
struct obd_import *imp;
imp = d->lpd_obd->u.cli.cl_import;
- /* Mark import deactivated now, so we don't try to reconnect if any
+ /*
+ * Mark import deactivated now, so we don't try to reconnect if any
* of the cleanup RPCs fails (e.g. ldlm cancel, etc). We don't
- * fully deactivate the import, or that would drop all requests. */
+ * fully deactivate the import because that would cause all requests
+ * to be dropped.
+ */
LASSERT(imp != NULL);
spin_lock(&imp->imp_lock);
imp->imp_deactive = 1;
ptlrpc_deactivate_import(imp);
- /* Some non-replayable imports (MDS's OSCs) are pinged, so just
+ /*
+ * Some non-replayable imports (MDS's OSCs) are pinged, so just
* delete it regardless. (It's safe to delete an import that was
- * never added.) */
+ * never added.)
+ */
ptlrpc_pinger_del_import(imp);
rc = ptlrpc_disconnect_import(imp, 0);
if (rc != 0)
RETURN(rc);
}
+/**
+ * Implementation of lu_device_operations::ldo_process_config.
+ *
+ * Process a Lustre configuration request.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] dev device to be processed
+ * \param[in] lcfg lustre_cfg, LCFG_PRE_CLEANUP or LCFG_CLEANUP
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_process_config(const struct lu_env *env,
struct lu_device *dev, struct lustre_cfg *lcfg)
{
.ldo_process_config = lwp_process_config,
};
+/**
+ * Initialize LWP device.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] lwp device to be initialized
+ * \param[in] ldt not used
+ * \param[in] cfg lustre_cfg contains remote target uuid
+ *
+ * \retval 0 on success
+ * \retval -ENODEV if the device name cannot be found
+ * \retval negative numbers on other errors
+ */
int lwp_init0(const struct lu_env *env, struct lwp_device *lwp,
struct lu_device_type *ldt, struct lustre_cfg *cfg)
{
RETURN(0);
}
+/**
+ * Implementation of lu_device_type_operations::ldto_device_free.
+ *
+ * Free a LWP device.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] lu device to be freed
+ *
+ * \retval NULL to indicate that this is the bottom device
+ * of the stack and there are no more devices
+ * below this one to be cleaned up.
+ */
static struct lu_device *lwp_device_free(const struct lu_env *env,
struct lu_device *lu)
{
RETURN(NULL);
}
+/**
+ * Implementation of lu_device_type_operations::ldto_device_alloc.
+ *
+ * Allocate a LWP device.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] ldt device type whose name is LUSTRE_LWP_NAME
+ * \param[in] lcfg lustre_cfg contains remote target UUID
+ *
+ * \retval pointer of allocated LWP device on success
+ * \retval ERR_PTR(errno) on error
+ */
static struct lu_device *lwp_device_alloc(const struct lu_env *env,
- struct lu_device_type *t,
+ struct lu_device_type *ldt,
struct lustre_cfg *lcfg)
{
struct lwp_device *lwp;
- struct lu_device *l;
+ struct lu_device *ludev;
OBD_ALLOC_PTR(lwp);
if (lwp == NULL) {
- l = ERR_PTR(-ENOMEM);
+ ludev = ERR_PTR(-ENOMEM);
} else {
int rc;
- l = lwp2lu_dev(lwp);
- lu_device_init(&lwp->lpd_dev, t);
- rc = lwp_init0(env, lwp, t, lcfg);
+ ludev = lwp2lu_dev(lwp);
+ lu_device_init(&lwp->lpd_dev, ldt);
+ rc = lwp_init0(env, lwp, ldt, lcfg);
if (rc != 0) {
- lwp_device_free(env, l);
- l = ERR_PTR(rc);
+ lwp_device_free(env, ludev);
+ ludev = ERR_PTR(rc);
}
}
- return l;
+ return ludev;
}
+/**
+ * Implementation of lu_device_type_operations::ltdo_device_fini.
+ *
+ * Finalize LWP device.
+ *
+ * \param[in] env environment passed by caller
+ * \param[in] ludev device to be finalized
+ *
+ * \retval NULL on success
+ */
static struct lu_device *lwp_device_fini(const struct lu_env *env,
- struct lu_device *d)
+ struct lu_device *ludev)
{
- struct lwp_device *m = lu2lwp_dev(d);
+ struct lwp_device *m = lu2lwp_dev(ludev);
struct obd_import *imp;
int rc;
ENTRY;
.ldt_ctx_tags = LCT_MD_THREAD
};
+/**
+ * Implementation of OBD device operations obd_ops::o_connect.
+ *
+ * Create export for LWP, and connect to target server.
+ *
+ * \param[in] env the environment passed by caller
+ * \param[out] exp export for the connection to be established
+ * \param[in] obd OBD device to perform the connect on
+ * \param[in] cluuid UUID of the OBD device
+ * \param[in] data connect data containing compatibility flags
+ * \param[in] localdata not used
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_obd_connect(const struct lu_env *env, struct obd_export **exp,
struct obd_device *obd, struct obd_uuid *cluuid,
struct obd_connect_data *data, void *localdata)
*exp = class_conn2export(&conn);
lwp->lpd_exp = *exp;
- /* Why should there ever be more than 1 connect? */
lwp->lpd_connects++;
LASSERT(lwp->lpd_connects == 1);
return rc;
}
+/**
+ * Implementation of OBD device operations obd_ops::o_disconnect.
+ *
+ * Release export for the LWP. Only disconnect the underlying layers
+ * on the final disconnect.
+ *
+ * \param[in] exp the export to perform disconnect on
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_obd_disconnect(struct obd_export *exp)
{
struct obd_device *obd = exp->exp_obd;
int rc;
ENTRY;
- /* Only disconnect the underlying layers on the final disconnect. */
LASSERT(lwp->lpd_connects == 1);
lwp->lpd_connects--;
RETURN(rc);
}
+/**
+ * Handle import events for the LWP device.
+ *
+ * \param[in] obd OBD device associated with the import
+ * \param[in] imp the import which event happened on
+ * \param[in] event event type
+ *
+ * \retval 0 on success
+ * \retval negative number on error
+ */
static int lwp_import_event(struct obd_device *obd, struct obd_import *imp,
enum obd_import_event event)
{
git://git.whamcloud.com / fs / lustre-release.git / commitdiff