drivers/staging/lustre/lustre/llite/lcommon_cl.c - arm/linux - Git at Google

 /*
  * 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.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
 /*
  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
  * Copyright (c) 2011, 2015, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre is a trademark of Sun Microsystems, Inc.
  *
  * cl code shared between vvp and liblustre (and other Lustre clients in the
  * future).
  *
  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  */

 #define DEBUG_SUBSYSTEM S_LLITE

 #include <linux/libcfs/libcfs.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/quotaops.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 #include <linux/rbtree.h>

 #include <obd.h>
 #include <obd_support.h>
 #include <lustre_fid.h>
 #include <lustre_dlm.h>
 #include <lustre_mdc.h>
 #include <cl_object.h>

 #include "llite_internal.h"

 /*
  * ccc_ prefix stands for "Common Client Code".
  */

 /*****************************************************************************
  *
  * Vvp device and device type functions.
  *
  */

 /**
  * An `emergency' environment used by cl_inode_fini() when cl_env_get()
  * fails. Access to this environment is serialized by cl_inode_fini_guard
  * mutex.
  */
 struct lu_env *cl_inode_fini_env;
 u16 cl_inode_fini_refcheck;

 /**
  * A mutex serializing calls to slp_inode_fini() under extreme memory
  * pressure, when environments cannot be allocated.
  */
 static DEFINE_MUTEX(cl_inode_fini_guard);

 int cl_setattr_ost(struct cl_object *obj, const struct iattr *attr,
 		   unsigned int attr_flags)
 {
 	struct lu_env *env;
 	struct cl_io  *io;
 	int	    result;
 	u16 refcheck;

 	env = cl_env_get(&refcheck);
 	if (IS_ERR(env))
 		return PTR_ERR(env);

 	io = vvp_env_thread_io(env);
 	io->ci_obj = obj;
 	io->ci_verify_layout = 1;

 	io->u.ci_setattr.sa_attr.lvb_atime = LTIME_S(attr->ia_atime);
 	io->u.ci_setattr.sa_attr.lvb_mtime = LTIME_S(attr->ia_mtime);
 	io->u.ci_setattr.sa_attr.lvb_ctime = LTIME_S(attr->ia_ctime);
 	io->u.ci_setattr.sa_attr.lvb_size = attr->ia_size;
 	io->u.ci_setattr.sa_attr_flags = attr_flags;
 	io->u.ci_setattr.sa_valid = attr->ia_valid;
 	io->u.ci_setattr.sa_parent_fid = lu_object_fid(&obj->co_lu);

 again:
 	if (cl_io_init(env, io, CIT_SETATTR, io->ci_obj) == 0) {
 		struct vvp_io *vio = vvp_env_io(env);

 		if (attr->ia_valid & ATTR_FILE)
 			/* populate the file descriptor for ftruncate to honor
 			 * group lock - see LU-787
 			 */
 			vio->vui_fd = LUSTRE_FPRIVATE(attr->ia_file);

 		result = cl_io_loop(env, io);
 	} else {
 		result = io->ci_result;
 	}
 	cl_io_fini(env, io);
 	if (unlikely(io->ci_need_restart))
 		goto again;

 	cl_env_put(env, &refcheck);
 	return result;
 }

 /**
  * Initialize or update CLIO structures for regular files when new
  * meta-data arrives from the server.
  *
  * \param inode regular file inode
  * \param md    new file metadata from MDS
  * - allocates cl_object if necessary,
  * - updated layout, if object was already here.
  */
 int cl_file_inode_init(struct inode *inode, struct lustre_md *md)
 {
 	struct lu_env	*env;
 	struct ll_inode_info *lli;
 	struct cl_object     *clob;
 	struct lu_site       *site;
 	struct lu_fid	*fid;
 	struct cl_object_conf conf = {
 		.coc_inode = inode,
 		.u = {
 			.coc_layout = md->layout,
 		}
 	};
 	int result = 0;
 	u16 refcheck;

 	LASSERT(md->body->mbo_valid & OBD_MD_FLID);
 	LASSERT(S_ISREG(inode->i_mode));

 	env = cl_env_get(&refcheck);
 	if (IS_ERR(env))
 		return PTR_ERR(env);

 	site = ll_i2sbi(inode)->ll_site;
 	lli  = ll_i2info(inode);
 	fid  = &lli->lli_fid;
 	LASSERT(fid_is_sane(fid));

 	if (!lli->lli_clob) {
 		/* clob is slave of inode, empty lli_clob means for new inode,
 		 * there is no clob in cache with the given fid, so it is
 		 * unnecessary to perform lookup-alloc-lookup-insert, just
 		 * alloc and insert directly.
 		 */
 		LASSERT(inode->i_state & I_NEW);
 		conf.coc_lu.loc_flags = LOC_F_NEW;
 		clob = cl_object_find(env, lu2cl_dev(site->ls_top_dev),
 				      fid, &conf);
 		if (!IS_ERR(clob)) {
 			/*
 			 * No locking is necessary, as new inode is
 			 * locked by I_NEW bit.
 			 */
 			lli->lli_clob = clob;
 			lu_object_ref_add(&clob->co_lu, "inode", inode);
 		} else {
 			result = PTR_ERR(clob);
 		}
 	} else {
 		result = cl_conf_set(env, lli->lli_clob, &conf);
 	}

 	cl_env_put(env, &refcheck);

 	if (result != 0)
 		CERROR("Failure to initialize cl object " DFID ": %d\n",
 		       PFID(fid), result);
 	return result;
 }

 /**
  * Wait for others drop their references of the object at first, then we drop
  * the last one, which will lead to the object be destroyed immediately.
  * Must be called after cl_object_kill() against this object.
  *
  * The reason we want to do this is: destroying top object will wait for sub
  * objects being destroyed first, so we can't let bottom layer (e.g. from ASTs)
  * to initiate top object destroying which may deadlock. See bz22520.
  */
 static void cl_object_put_last(struct lu_env *env, struct cl_object *obj)
 {
 	struct lu_object_header *header = obj->co_lu.lo_header;
 	wait_queue_entry_t	   waiter;

 	if (unlikely(atomic_read(&header->loh_ref) != 1)) {
 		struct lu_site *site = obj->co_lu.lo_dev->ld_site;
 		struct lu_site_bkt_data *bkt;

 		bkt = lu_site_bkt_from_fid(site, &header->loh_fid);

 		init_waitqueue_entry(&waiter, current);
 		add_wait_queue(&bkt->lsb_marche_funebre, &waiter);

 		while (1) {
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			if (atomic_read(&header->loh_ref) == 1)
 				break;
 			schedule();
 		}

 		set_current_state(TASK_RUNNING);
 		remove_wait_queue(&bkt->lsb_marche_funebre, &waiter);
 	}

 	cl_object_put(env, obj);
 }

 void cl_inode_fini(struct inode *inode)
 {
 	struct lu_env	   *env;
 	struct ll_inode_info    *lli  = ll_i2info(inode);
 	struct cl_object	*clob = lli->lli_clob;
 	u16 refcheck;
 	int emergency;

 	if (clob) {
 		env = cl_env_get(&refcheck);
 		emergency = IS_ERR(env);
 		if (emergency) {
 			mutex_lock(&cl_inode_fini_guard);
 			LASSERT(cl_inode_fini_env);
 			env = cl_inode_fini_env;
 		}
 		/*
 		 * cl_object cache is a slave to inode cache (which, in turn
 		 * is a slave to dentry cache), don't keep cl_object in memory
 		 * when its master is evicted.
 		 */
 		cl_object_kill(env, clob);
 		lu_object_ref_del(&clob->co_lu, "inode", inode);
 		cl_object_put_last(env, clob);
 		lli->lli_clob = NULL;
 		if (emergency)
 			mutex_unlock(&cl_inode_fini_guard);
 		else
 			cl_env_put(env, &refcheck);
 	}
 }

 /**
  * build inode number from passed @fid
  */
 __u64 cl_fid_build_ino(const struct lu_fid *fid, int api32)
 {
 	if (BITS_PER_LONG == 32 || api32)
 		return fid_flatten32(fid);
 	else
 		return fid_flatten(fid);
 }

 /**
  * build inode generation from passed @fid.  If our FID overflows the 32-bit
  * inode number then return a non-zero generation to distinguish them.
  */
 __u32 cl_fid_build_gen(const struct lu_fid *fid)
 {
 	__u32 gen;

 	if (fid_is_igif(fid)) {
 		gen = lu_igif_gen(fid);
 		return gen;
 	}

 	gen = fid_flatten(fid) >> 32;
 	return gen;
 }
	/*
	* 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.gnu.org/licenses/gpl-2.0.html
	*
	* GPL HEADER END
	*/
	/*
	* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
	* Use is subject to license terms.
	*
	* Copyright (c) 2011, 2015, Intel Corporation.
	*/
	/*
	* This file is part of Lustre, http://www.lustre.org/
	* Lustre is a trademark of Sun Microsystems, Inc.
	*
	* cl code shared between vvp and liblustre (and other Lustre clients in the
	* future).
	*
	* Author: Nikita Danilov <nikita.danilov@sun.com>
	*/

	#define DEBUG_SUBSYSTEM S_LLITE

	#include <linux/libcfs/libcfs.h>
	#include <linux/fs.h>
	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/quotaops.h>
	#include <linux/highmem.h>
	#include <linux/pagemap.h>
	#include <linux/rbtree.h>

	#include <obd.h>
	#include <obd_support.h>
	#include <lustre_fid.h>
	#include <lustre_dlm.h>
	#include <lustre_mdc.h>
	#include <cl_object.h>

	#include "llite_internal.h"

	/*
	* ccc_ prefix stands for "Common Client Code".
	*/

	/*****************************************************************************
	*
	* Vvp device and device type functions.
	*
	*/

	/**
	* An `emergency' environment used by cl_inode_fini() when cl_env_get()
	* fails. Access to this environment is serialized by cl_inode_fini_guard
	* mutex.
	*/
	struct lu_env *cl_inode_fini_env;
	u16 cl_inode_fini_refcheck;

	/**
	* A mutex serializing calls to slp_inode_fini() under extreme memory
	* pressure, when environments cannot be allocated.
	*/
	static DEFINE_MUTEX(cl_inode_fini_guard);

	int cl_setattr_ost(struct cl_object obj, const struct iattr attr,
	unsigned int attr_flags)
	{
	struct lu_env *env;
	struct cl_io *io;
	int result;
	u16 refcheck;

	env = cl_env_get(&refcheck);
	if (IS_ERR(env))
	return PTR_ERR(env);

	io = vvp_env_thread_io(env);
	io->ci_obj = obj;
	io->ci_verify_layout = 1;

	io->u.ci_setattr.sa_attr.lvb_atime = LTIME_S(attr->ia_atime);
	io->u.ci_setattr.sa_attr.lvb_mtime = LTIME_S(attr->ia_mtime);
	io->u.ci_setattr.sa_attr.lvb_ctime = LTIME_S(attr->ia_ctime);
	io->u.ci_setattr.sa_attr.lvb_size = attr->ia_size;
	io->u.ci_setattr.sa_attr_flags = attr_flags;
	io->u.ci_setattr.sa_valid = attr->ia_valid;
	io->u.ci_setattr.sa_parent_fid = lu_object_fid(&obj->co_lu);

	again:
	if (cl_io_init(env, io, CIT_SETATTR, io->ci_obj) == 0) {
	struct vvp_io *vio = vvp_env_io(env);

	if (attr->ia_valid & ATTR_FILE)
	/* populate the file descriptor for ftruncate to honor
	* group lock - see LU-787
	*/
	vio->vui_fd = LUSTRE_FPRIVATE(attr->ia_file);

	result = cl_io_loop(env, io);
	} else {
	result = io->ci_result;
	}
	cl_io_fini(env, io);
	if (unlikely(io->ci_need_restart))
	goto again;

	cl_env_put(env, &refcheck);
	return result;
	}

	/**
	* Initialize or update CLIO structures for regular files when new
	* meta-data arrives from the server.
	*
	* \param inode regular file inode
	* \param md new file metadata from MDS
	* - allocates cl_object if necessary,
	* - updated layout, if object was already here.
	*/
	int cl_file_inode_init(struct inode inode, struct lustre_md md)
	{
	struct lu_env *env;
	struct ll_inode_info *lli;
	struct cl_object *clob;
	struct lu_site *site;
	struct lu_fid *fid;
	struct cl_object_conf conf = {
	.coc_inode = inode,
	.u = {
	.coc_layout = md->layout,
	}
	};
	int result = 0;
	u16 refcheck;

	LASSERT(md->body->mbo_valid & OBD_MD_FLID);
	LASSERT(S_ISREG(inode->i_mode));

	env = cl_env_get(&refcheck);
	if (IS_ERR(env))
	return PTR_ERR(env);

	site = ll_i2sbi(inode)->ll_site;
	lli = ll_i2info(inode);
	fid = &lli->lli_fid;
	LASSERT(fid_is_sane(fid));

	if (!lli->lli_clob) {
	/* clob is slave of inode, empty lli_clob means for new inode,
	* there is no clob in cache with the given fid, so it is
	* unnecessary to perform lookup-alloc-lookup-insert, just
	* alloc and insert directly.
	*/
	LASSERT(inode->i_state & I_NEW);
	conf.coc_lu.loc_flags = LOC_F_NEW;
	clob = cl_object_find(env, lu2cl_dev(site->ls_top_dev),
	fid, &conf);
	if (!IS_ERR(clob)) {
	/*
	* No locking is necessary, as new inode is
	* locked by I_NEW bit.
	*/
	lli->lli_clob = clob;
	lu_object_ref_add(&clob->co_lu, "inode", inode);
	} else {
	result = PTR_ERR(clob);
	}
	} else {
	result = cl_conf_set(env, lli->lli_clob, &conf);
	}

	cl_env_put(env, &refcheck);

	if (result != 0)
	CERROR("Failure to initialize cl object " DFID ": %d\n",
	PFID(fid), result);
	return result;
	}

	/**
	* Wait for others drop their references of the object at first, then we drop
	* the last one, which will lead to the object be destroyed immediately.
	* Must be called after cl_object_kill() against this object.
	*
	* The reason we want to do this is: destroying top object will wait for sub
	* objects being destroyed first, so we can't let bottom layer (e.g. from ASTs)
	* to initiate top object destroying which may deadlock. See bz22520.
	*/
	static void cl_object_put_last(struct lu_env env, struct cl_object obj)
	{
	struct lu_object_header *header = obj->co_lu.lo_header;
	wait_queue_entry_t waiter;

	if (unlikely(atomic_read(&header->loh_ref) != 1)) {
	struct lu_site *site = obj->co_lu.lo_dev->ld_site;
	struct lu_site_bkt_data *bkt;

	bkt = lu_site_bkt_from_fid(site, &header->loh_fid);

	init_waitqueue_entry(&waiter, current);
	add_wait_queue(&bkt->lsb_marche_funebre, &waiter);

	while (1) {
	set_current_state(TASK_UNINTERRUPTIBLE);
	if (atomic_read(&header->loh_ref) == 1)
	break;
	schedule();
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&bkt->lsb_marche_funebre, &waiter);
	}

	cl_object_put(env, obj);
	}

	void cl_inode_fini(struct inode *inode)
	{
	struct lu_env *env;
	struct ll_inode_info *lli = ll_i2info(inode);
	struct cl_object *clob = lli->lli_clob;
	u16 refcheck;
	int emergency;

	if (clob) {
	env = cl_env_get(&refcheck);
	emergency = IS_ERR(env);
	if (emergency) {
	mutex_lock(&cl_inode_fini_guard);
	LASSERT(cl_inode_fini_env);
	env = cl_inode_fini_env;
	}
	/*
	* cl_object cache is a slave to inode cache (which, in turn
	* is a slave to dentry cache), don't keep cl_object in memory
	* when its master is evicted.
	*/
	cl_object_kill(env, clob);
	lu_object_ref_del(&clob->co_lu, "inode", inode);
	cl_object_put_last(env, clob);
	lli->lli_clob = NULL;
	if (emergency)
	mutex_unlock(&cl_inode_fini_guard);
	else
	cl_env_put(env, &refcheck);
	}
	}

	/**
	* build inode number from passed @fid
	*/
	__u64 cl_fid_build_ino(const struct lu_fid *fid, int api32)
	{
	if (BITS_PER_LONG == 32 \|\| api32)
	return fid_flatten32(fid);
	else
	return fid_flatten(fid);
	}

	/**
	* build inode generation from passed @fid. If our FID overflows the 32-bit
	* inode number then return a non-zero generation to distinguish them.
	*/
	__u32 cl_fid_build_gen(const struct lu_fid *fid)
	{
	__u32 gen;

	if (fid_is_igif(fid)) {
	gen = lu_igif_gen(fid);
	return gen;
	}

	gen = fid_flatten(fid) >> 32;
	return gen;
	}