drivers/staging/lustre/lustre/mdc/mdc_lib.c

/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_MDC
#include "../include/lustre_net.h"
#include "../include/lustre/lustre_idl.h"
#include "mdc_internal.h"


static void __mdc_pack_body(struct mdt_body *b, __u32 suppgid)
{
	LASSERT(b != NULL);

	b->suppgid = suppgid;
	b->uid = from_kuid(&init_user_ns, current_uid());
	b->gid = from_kgid(&init_user_ns, current_gid());
	b->fsuid = from_kuid(&init_user_ns, current_fsuid());
	b->fsgid = from_kgid(&init_user_ns, current_fsgid());
	b->capability = cfs_curproc_cap_pack();
}

void mdc_pack_capa(struct ptlrpc_request *req,
		   const struct req_msg_field *field,
		   struct obd_capa *oc)
{
	struct req_capsule *pill = &req->rq_pill;
	struct lustre_capa *c;

	if (oc == NULL) {
		LASSERT(req_capsule_get_size(pill, field, RCL_CLIENT) == 0);
		return;
	}

	c = req_capsule_client_get(pill, field);
	LASSERT(c != NULL);
	capa_cpy(c, oc);
	DEBUG_CAPA(D_SEC, c, "pack");
}

void mdc_is_subdir_pack(struct ptlrpc_request *req, const struct lu_fid *pfid,
			const struct lu_fid *cfid, int flags)
{
	struct mdt_body *b = req_capsule_client_get(&req->rq_pill,
						    &RMF_MDT_BODY);

	if (pfid) {
		b->fid1 = *pfid;
		b->valid = OBD_MD_FLID;
	}
	if (cfid)
		b->fid2 = *cfid;
	b->flags = flags;
}

void mdc_swap_layouts_pack(struct ptlrpc_request *req,
			   struct md_op_data *op_data)
{
	struct mdt_body *b = req_capsule_client_get(&req->rq_pill,
						    &RMF_MDT_BODY);

	__mdc_pack_body(b, op_data->op_suppgids[0]);
	b->fid1 = op_data->op_fid1;
	b->fid2 = op_data->op_fid2;
	b->valid |= OBD_MD_FLID;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);
	mdc_pack_capa(req, &RMF_CAPA2, op_data->op_capa2);
}

void mdc_pack_body(struct ptlrpc_request *req,
		   const struct lu_fid *fid, struct obd_capa *oc,
		   __u64 valid, int ea_size, __u32 suppgid, int flags)
{
	struct mdt_body *b = req_capsule_client_get(&req->rq_pill,
						    &RMF_MDT_BODY);
	LASSERT(b != NULL);
	b->valid = valid;
	b->eadatasize = ea_size;
	b->flags = flags;
	__mdc_pack_body(b, suppgid);
	if (fid) {
		b->fid1 = *fid;
		b->valid |= OBD_MD_FLID;
		mdc_pack_capa(req, &RMF_CAPA1, oc);
	}
}

void mdc_readdir_pack(struct ptlrpc_request *req, __u64 pgoff,
		      __u32 size, const struct lu_fid *fid, struct obd_capa *oc)
{
	struct mdt_body *b = req_capsule_client_get(&req->rq_pill,
						    &RMF_MDT_BODY);
	b->fid1 = *fid;
	b->valid |= OBD_MD_FLID;
	b->size = pgoff;		       /* !! */
	b->nlink = size;			/* !! */
	__mdc_pack_body(b, -1);
	b->mode = LUDA_FID | LUDA_TYPE;

	mdc_pack_capa(req, &RMF_CAPA1, oc);
}

/* packing of MDS records */
void mdc_create_pack(struct ptlrpc_request *req, struct md_op_data *op_data,
		     const void *data, int datalen, __u32 mode,
		     __u32 uid, __u32 gid, cfs_cap_t cap_effective, __u64 rdev)
{
	struct mdt_rec_create	*rec;
	char			*tmp;
	__u64			 flags;

	CLASSERT(sizeof(struct mdt_rec_reint) == sizeof(struct mdt_rec_create));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);


	rec->cr_opcode   = REINT_CREATE;
	rec->cr_fsuid    = uid;
	rec->cr_fsgid    = gid;
	rec->cr_cap      = cap_effective;
	rec->cr_fid1     = op_data->op_fid1;
	rec->cr_fid2     = op_data->op_fid2;
	rec->cr_mode     = mode;
	rec->cr_rdev     = rdev;
	rec->cr_time     = op_data->op_mod_time;
	rec->cr_suppgid1 = op_data->op_suppgids[0];
	rec->cr_suppgid2 = op_data->op_suppgids[1];
	flags = op_data->op_flags & MF_SOM_LOCAL_FLAGS;
	if (op_data->op_bias & MDS_CREATE_VOLATILE)
		flags |= MDS_OPEN_VOLATILE;
	set_mrc_cr_flags(rec, flags);
	rec->cr_bias     = op_data->op_bias;
	rec->cr_umask    = current_umask();

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);

	tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
	LOGL0(op_data->op_name, op_data->op_namelen, tmp);

	if (data) {
		tmp = req_capsule_client_get(&req->rq_pill, &RMF_EADATA);
		memcpy(tmp, data, datalen);
	}
}

static __u64 mds_pack_open_flags(__u64 flags, __u32 mode)
{
	__u64 cr_flags = (flags & (FMODE_READ | FMODE_WRITE |
				   MDS_OPEN_HAS_EA | MDS_OPEN_HAS_OBJS |
				   MDS_OPEN_OWNEROVERRIDE | MDS_OPEN_LOCK |
				   MDS_OPEN_BY_FID | MDS_OPEN_LEASE |
				   MDS_OPEN_RELEASE));
	if (flags & O_CREAT)
		cr_flags |= MDS_OPEN_CREAT;
	if (flags & O_EXCL)
		cr_flags |= MDS_OPEN_EXCL;
	if (flags & O_TRUNC)
		cr_flags |= MDS_OPEN_TRUNC;
	if (flags & O_APPEND)
		cr_flags |= MDS_OPEN_APPEND;
	if (flags & O_SYNC)
		cr_flags |= MDS_OPEN_SYNC;
	if (flags & O_DIRECTORY)
		cr_flags |= MDS_OPEN_DIRECTORY;
	if (flags & __FMODE_EXEC)
		cr_flags |= MDS_FMODE_EXEC;
	if (cl_is_lov_delay_create(flags))
		cr_flags |= MDS_OPEN_DELAY_CREATE;

	if (flags & O_NONBLOCK)
		cr_flags |= MDS_OPEN_NORESTORE;

	return cr_flags;
}

/* packing of MDS records */
void mdc_open_pack(struct ptlrpc_request *req, struct md_op_data *op_data,
		   __u32 mode, __u64 rdev, __u64 flags, const void *lmm,
		   int lmmlen)
{
	struct mdt_rec_create *rec;
	char *tmp;
	__u64 cr_flags;

	CLASSERT(sizeof(struct mdt_rec_reint) == sizeof(struct mdt_rec_create));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);

	/* XXX do something about time, uid, gid */
	rec->cr_opcode   = REINT_OPEN;
	rec->cr_fsuid    = from_kuid(&init_user_ns, current_fsuid());
	rec->cr_fsgid    = from_kgid(&init_user_ns, current_fsgid());
	rec->cr_cap      = cfs_curproc_cap_pack();
	rec->cr_fid1 = op_data->op_fid1;
	rec->cr_fid2 = op_data->op_fid2;

	rec->cr_mode     = mode;
	cr_flags = mds_pack_open_flags(flags, mode);
	rec->cr_rdev     = rdev;
	rec->cr_time     = op_data->op_mod_time;
	rec->cr_suppgid1 = op_data->op_suppgids[0];
	rec->cr_suppgid2 = op_data->op_suppgids[1];
	rec->cr_bias     = op_data->op_bias;
	rec->cr_umask    = current_umask();
	rec->cr_old_handle = op_data->op_handle;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);
	/* the next buffer is child capa, which is used for replay,
	 * will be packed from the data in reply message. */

	if (op_data->op_name) {
		tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
		LOGL0(op_data->op_name, op_data->op_namelen, tmp);
		if (op_data->op_bias & MDS_CREATE_VOLATILE)
			cr_flags |= MDS_OPEN_VOLATILE;
	}

	if (lmm) {
		cr_flags |= MDS_OPEN_HAS_EA;
		tmp = req_capsule_client_get(&req->rq_pill, &RMF_EADATA);
		memcpy(tmp, lmm, lmmlen);
	}
	set_mrc_cr_flags(rec, cr_flags);
}

static inline __u64 attr_pack(unsigned int ia_valid)
{
	__u64 sa_valid = 0;

	if (ia_valid & ATTR_MODE)
		sa_valid |= MDS_ATTR_MODE;
	if (ia_valid & ATTR_UID)
		sa_valid |= MDS_ATTR_UID;
	if (ia_valid & ATTR_GID)
		sa_valid |= MDS_ATTR_GID;
	if (ia_valid & ATTR_SIZE)
		sa_valid |= MDS_ATTR_SIZE;
	if (ia_valid & ATTR_ATIME)
		sa_valid |= MDS_ATTR_ATIME;
	if (ia_valid & ATTR_MTIME)
		sa_valid |= MDS_ATTR_MTIME;
	if (ia_valid & ATTR_CTIME)
		sa_valid |= MDS_ATTR_CTIME;
	if (ia_valid & ATTR_ATIME_SET)
		sa_valid |= MDS_ATTR_ATIME_SET;
	if (ia_valid & ATTR_MTIME_SET)
		sa_valid |= MDS_ATTR_MTIME_SET;
	if (ia_valid & ATTR_FORCE)
		sa_valid |= MDS_ATTR_FORCE;
	if (ia_valid & ATTR_ATTR_FLAG)
		sa_valid |= MDS_ATTR_ATTR_FLAG;
	if (ia_valid & ATTR_KILL_SUID)
		sa_valid |=  MDS_ATTR_KILL_SUID;
	if (ia_valid & ATTR_KILL_SGID)
		sa_valid |= MDS_ATTR_KILL_SGID;
	if (ia_valid & ATTR_CTIME_SET)
		sa_valid |= MDS_ATTR_CTIME_SET;
	if (ia_valid & ATTR_FROM_OPEN)
		sa_valid |= MDS_ATTR_FROM_OPEN;
	if (ia_valid & ATTR_BLOCKS)
		sa_valid |= MDS_ATTR_BLOCKS;
	if (ia_valid & MDS_OPEN_OWNEROVERRIDE)
		/* NFSD hack (see bug 5781) */
		sa_valid |= MDS_OPEN_OWNEROVERRIDE;
	return sa_valid;
}

static void mdc_setattr_pack_rec(struct mdt_rec_setattr *rec,
				 struct md_op_data *op_data)
{
	rec->sa_opcode  = REINT_SETATTR;
	rec->sa_fsuid   = from_kuid(&init_user_ns, current_fsuid());
	rec->sa_fsgid   = from_kgid(&init_user_ns, current_fsgid());
	rec->sa_cap     = cfs_curproc_cap_pack();
	rec->sa_suppgid = -1;

	rec->sa_fid    = op_data->op_fid1;
	rec->sa_valid  = attr_pack(op_data->op_attr.ia_valid);
	rec->sa_mode   = op_data->op_attr.ia_mode;
	rec->sa_uid    = from_kuid(&init_user_ns, op_data->op_attr.ia_uid);
	rec->sa_gid    = from_kgid(&init_user_ns, op_data->op_attr.ia_gid);
	rec->sa_size   = op_data->op_attr.ia_size;
	rec->sa_blocks = op_data->op_attr_blocks;
	rec->sa_atime  = LTIME_S(op_data->op_attr.ia_atime);
	rec->sa_mtime  = LTIME_S(op_data->op_attr.ia_mtime);
	rec->sa_ctime  = LTIME_S(op_data->op_attr.ia_ctime);
	rec->sa_attr_flags =
			((struct ll_iattr *)&op_data->op_attr)->ia_attr_flags;
	if ((op_data->op_attr.ia_valid & ATTR_GID) &&
	    in_group_p(op_data->op_attr.ia_gid))
		rec->sa_suppgid =
			from_kgid(&init_user_ns, op_data->op_attr.ia_gid);
	else
		rec->sa_suppgid = op_data->op_suppgids[0];

	rec->sa_bias = op_data->op_bias;
}

static void mdc_ioepoch_pack(struct mdt_ioepoch *epoch,
			     struct md_op_data *op_data)
{
	memcpy(&epoch->handle, &op_data->op_handle, sizeof(epoch->handle));
	epoch->ioepoch = op_data->op_ioepoch;
	epoch->flags = op_data->op_flags & MF_SOM_LOCAL_FLAGS;
}

void mdc_setattr_pack(struct ptlrpc_request *req, struct md_op_data *op_data,
		      void *ea, int ealen, void *ea2, int ea2len)
{
	struct mdt_rec_setattr *rec;
	struct mdt_ioepoch *epoch;
	struct lov_user_md *lum = NULL;

	CLASSERT(sizeof(struct mdt_rec_reint) ==
					sizeof(struct mdt_rec_setattr));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);
	mdc_setattr_pack_rec(rec, op_data);

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);

	if (op_data->op_flags & (MF_SOM_CHANGE | MF_EPOCH_OPEN)) {
		epoch = req_capsule_client_get(&req->rq_pill, &RMF_MDT_EPOCH);
		mdc_ioepoch_pack(epoch, op_data);
	}

	if (ealen == 0)
		return;

	lum = req_capsule_client_get(&req->rq_pill, &RMF_EADATA);
	if (ea == NULL) { /* Remove LOV EA */
		lum->lmm_magic = LOV_USER_MAGIC_V1;
		lum->lmm_stripe_size = 0;
		lum->lmm_stripe_count = 0;
		lum->lmm_stripe_offset = (typeof(lum->lmm_stripe_offset))(-1);
	} else {
		memcpy(lum, ea, ealen);
	}

	if (ea2len == 0)
		return;

	memcpy(req_capsule_client_get(&req->rq_pill, &RMF_LOGCOOKIES), ea2,
	       ea2len);
}

void mdc_unlink_pack(struct ptlrpc_request *req, struct md_op_data *op_data)
{
	struct mdt_rec_unlink *rec;
	char *tmp;

	CLASSERT(sizeof(struct mdt_rec_reint) == sizeof(struct mdt_rec_unlink));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);
	LASSERT(rec != NULL);

	rec->ul_opcode   = op_data->op_cli_flags & CLI_RM_ENTRY ?
					REINT_RMENTRY : REINT_UNLINK;
	rec->ul_fsuid    = op_data->op_fsuid;
	rec->ul_fsgid    = op_data->op_fsgid;
	rec->ul_cap      = op_data->op_cap;
	rec->ul_mode     = op_data->op_mode;
	rec->ul_suppgid1 = op_data->op_suppgids[0];
	rec->ul_suppgid2 = -1;
	rec->ul_fid1     = op_data->op_fid1;
	rec->ul_fid2     = op_data->op_fid2;
	rec->ul_time     = op_data->op_mod_time;
	rec->ul_bias     = op_data->op_bias;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);

	tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
	LASSERT(tmp != NULL);
	LOGL0(op_data->op_name, op_data->op_namelen, tmp);
}

void mdc_link_pack(struct ptlrpc_request *req, struct md_op_data *op_data)
{
	struct mdt_rec_link *rec;
	char *tmp;

	CLASSERT(sizeof(struct mdt_rec_reint) == sizeof(struct mdt_rec_link));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);
	LASSERT(rec != NULL);

	rec->lk_opcode   = REINT_LINK;
	rec->lk_fsuid    = op_data->op_fsuid; /* current->fsuid; */
	rec->lk_fsgid    = op_data->op_fsgid; /* current->fsgid; */
	rec->lk_cap      = op_data->op_cap;   /* current->cap_effective; */
	rec->lk_suppgid1 = op_data->op_suppgids[0];
	rec->lk_suppgid2 = op_data->op_suppgids[1];
	rec->lk_fid1     = op_data->op_fid1;
	rec->lk_fid2     = op_data->op_fid2;
	rec->lk_time     = op_data->op_mod_time;
	rec->lk_bias     = op_data->op_bias;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);
	mdc_pack_capa(req, &RMF_CAPA2, op_data->op_capa2);

	tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
	LOGL0(op_data->op_name, op_data->op_namelen, tmp);
}

void mdc_rename_pack(struct ptlrpc_request *req, struct md_op_data *op_data,
		     const char *old, int oldlen, const char *new, int newlen)
{
	struct mdt_rec_rename *rec;
	char *tmp;

	CLASSERT(sizeof(struct mdt_rec_reint) == sizeof(struct mdt_rec_rename));
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);

	/* XXX do something about time, uid, gid */
	rec->rn_opcode   = REINT_RENAME;
	rec->rn_fsuid    = op_data->op_fsuid;
	rec->rn_fsgid    = op_data->op_fsgid;
	rec->rn_cap      = op_data->op_cap;
	rec->rn_suppgid1 = op_data->op_suppgids[0];
	rec->rn_suppgid2 = op_data->op_suppgids[1];
	rec->rn_fid1     = op_data->op_fid1;
	rec->rn_fid2     = op_data->op_fid2;
	rec->rn_time     = op_data->op_mod_time;
	rec->rn_mode     = op_data->op_mode;
	rec->rn_bias     = op_data->op_bias;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);
	mdc_pack_capa(req, &RMF_CAPA2, op_data->op_capa2);

	tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
	LOGL0(old, oldlen, tmp);

	if (new) {
		tmp = req_capsule_client_get(&req->rq_pill, &RMF_SYMTGT);
		LOGL0(new, newlen, tmp);
	}
}

void mdc_getattr_pack(struct ptlrpc_request *req, __u64 valid, int flags,
		      struct md_op_data *op_data, int ea_size)
{
	struct mdt_body *b = req_capsule_client_get(&req->rq_pill,
						    &RMF_MDT_BODY);

	b->valid = valid;
	if (op_data->op_bias & MDS_CHECK_SPLIT)
		b->valid |= OBD_MD_FLCKSPLIT;
	if (op_data->op_bias & MDS_CROSS_REF)
		b->valid |= OBD_MD_FLCROSSREF;
	b->eadatasize = ea_size;
	b->flags = flags;
	__mdc_pack_body(b, op_data->op_suppgids[0]);

	b->fid1 = op_data->op_fid1;
	b->fid2 = op_data->op_fid2;
	b->valid |= OBD_MD_FLID;

	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);

	if (op_data->op_name) {
		char *tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);

		LOGL0(op_data->op_name, op_data->op_namelen, tmp);

	}
}

static void mdc_hsm_release_pack(struct ptlrpc_request *req,
				 struct md_op_data *op_data)
{
	if (op_data->op_bias & MDS_HSM_RELEASE) {
		struct close_data *data;
		struct ldlm_lock *lock;

		data = req_capsule_client_get(&req->rq_pill, &RMF_CLOSE_DATA);
		LASSERT(data != NULL);

		lock = ldlm_handle2lock(&op_data->op_lease_handle);
		if (lock != NULL) {
			data->cd_handle = lock->l_remote_handle;
			ldlm_lock_put(lock);
		}
		ldlm_cli_cancel(&op_data->op_lease_handle, LCF_LOCAL);

		data->cd_data_version = op_data->op_data_version;
		data->cd_fid = op_data->op_fid2;
	}
}

void mdc_close_pack(struct ptlrpc_request *req, struct md_op_data *op_data)
{
	struct mdt_ioepoch *epoch;
	struct mdt_rec_setattr *rec;

	epoch = req_capsule_client_get(&req->rq_pill, &RMF_MDT_EPOCH);
	rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);

	mdc_setattr_pack_rec(rec, op_data);
	mdc_pack_capa(req, &RMF_CAPA1, op_data->op_capa1);
	mdc_ioepoch_pack(epoch, op_data);
	mdc_hsm_release_pack(req, op_data);
}

static int mdc_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
{
	int rc;

	client_obd_list_lock(&cli->cl_loi_list_lock);
	rc = list_empty(&mcw->mcw_entry);
	client_obd_list_unlock(&cli->cl_loi_list_lock);
	return rc;
};

/* We record requests in flight in cli->cl_r_in_flight here.
 * There is only one write rpc possible in mdc anyway. If this to change
 * in the future - the code may need to be revisited. */
int mdc_enter_request(struct client_obd *cli)
{
	int rc = 0;
	struct mdc_cache_waiter mcw;
	struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);

	client_obd_list_lock(&cli->cl_loi_list_lock);
	if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
		list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
		init_waitqueue_head(&mcw.mcw_waitq);
		client_obd_list_unlock(&cli->cl_loi_list_lock);
		rc = l_wait_event(mcw.mcw_waitq, mdc_req_avail(cli, &mcw),
				  &lwi);
		if (rc) {
			client_obd_list_lock(&cli->cl_loi_list_lock);
			if (list_empty(&mcw.mcw_entry))
				cli->cl_r_in_flight--;
			list_del_init(&mcw.mcw_entry);
			client_obd_list_unlock(&cli->cl_loi_list_lock);
		}
	} else {
		cli->cl_r_in_flight++;
		client_obd_list_unlock(&cli->cl_loi_list_lock);
	}
	return rc;
}

void mdc_exit_request(struct client_obd *cli)
{
	struct list_head *l, *tmp;
	struct mdc_cache_waiter *mcw;

	client_obd_list_lock(&cli->cl_loi_list_lock);
	cli->cl_r_in_flight--;
	list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
		if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
			/* No free request slots anymore */
			break;
		}

		mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
		list_del_init(&mcw->mcw_entry);
		cli->cl_r_in_flight++;
		wake_up(&mcw->mcw_waitq);
	}
	/* Empty waiting list? Decrease reqs in-flight number */

	client_obd_list_unlock(&cli->cl_loi_list_lock);
}