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/*
* 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) 2008, 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.
*
* glimpse code shared between vvp and liblustre (and other Lustre clients in
* the future).
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
* Author: Oleg Drokin <oleg.drokin@sun.com>
*/
#include "../../include/linux/libcfs/libcfs.h"
#include "../include/obd_class.h"
#include "../include/obd_support.h"
#include "../include/obd.h"
#include "../include/lustre_dlm.h"
#include "../include/lustre_lite.h"
#include "../include/lustre_mdc.h"
#include <linux/pagemap.h>
#include <linux/file.h>
#include "../include/cl_object.h"
#include "../include/lclient.h"
#include "../llite/llite_internal.h"
static const struct cl_lock_descr whole_file = {
.cld_start = 0,
.cld_end = CL_PAGE_EOF,
.cld_mode = CLM_READ
};
/*
* Check whether file has possible unwriten pages.
*
* \retval 1 file is mmap-ed or has dirty pages
* 0 otherwise
*/
blkcnt_t dirty_cnt(struct inode *inode)
{
blkcnt_t cnt = 0;
struct ccc_object *vob = cl_inode2ccc(inode);
void *results[1];
if (inode->i_mapping)
cnt += radix_tree_gang_lookup_tag(&inode->i_mapping->page_tree,
results, 0, 1,
PAGECACHE_TAG_DIRTY);
if (cnt == 0 && atomic_read(&vob->cob_mmap_cnt) > 0)
cnt = 1;
return (cnt > 0) ? 1 : 0;
}
int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
struct inode *inode, struct cl_object *clob, int agl)
{
struct cl_lock_descr *descr = &ccc_env_info(env)->cti_descr;
struct cl_inode_info *lli = cl_i2info(inode);
const struct lu_fid *fid = lu_object_fid(&clob->co_lu);
struct ccc_io *cio = ccc_env_io(env);
struct cl_lock *lock;
int result;
result = 0;
if (!(lli->lli_flags & LLIF_MDS_SIZE_LOCK)) {
CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
if (lli->lli_has_smd) {
/* NOTE: this looks like DLM lock request, but it may
* not be one. Due to CEF_ASYNC flag (translated
* to LDLM_FL_HAS_INTENT by osc), this is
* glimpse request, that won't revoke any
* conflicting DLM locks held. Instead,
* ll_glimpse_callback() will be called on each
* client holding a DLM lock against this file,
* and resulting size will be returned for each
* stripe. DLM lock on [0, EOF] is acquired only
* if there were no conflicting locks. If there
* were conflicting locks, enqueuing or waiting
* fails with -ENAVAIL, but valid inode
* attributes are returned anyway.
*/
*descr = whole_file;
descr->cld_obj = clob;
descr->cld_mode = CLM_PHANTOM;
descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
if (agl)
descr->cld_enq_flags |= CEF_AGL;
cio->cui_glimpse = 1;
/*
* CEF_ASYNC is used because glimpse sub-locks cannot
* deadlock (because they never conflict with other
* locks) and, hence, can be enqueued out-of-order.
*
* CEF_MUST protects glimpse lock from conversion into
* a lockless mode.
*/
lock = cl_lock_request(env, io, descr, "glimpse",
current);
cio->cui_glimpse = 0;
if (!lock)
return 0;
if (IS_ERR(lock))
return PTR_ERR(lock);
LASSERT(agl == 0);
result = cl_wait(env, lock);
if (result == 0) {
cl_merge_lvb(env, inode);
if (cl_isize_read(inode) > 0 &&
inode->i_blocks == 0) {
/*
* LU-417: Add dirty pages block count
* lest i_blocks reports 0, some "cp" or
* "tar" may think it's a completely
* sparse file and skip it.
*/
inode->i_blocks = dirty_cnt(inode);
}
cl_unuse(env, lock);
}
cl_lock_release(env, lock, "glimpse", current);
} else {
CDEBUG(D_DLMTRACE, "No objects for inode\n");
cl_merge_lvb(env, inode);
}
}
return result;
}
static int cl_io_get(struct inode *inode, struct lu_env **envout,
struct cl_io **ioout, int *refcheck)
{
struct lu_env *env;
struct cl_io *io;
struct cl_inode_info *lli = cl_i2info(inode);
struct cl_object *clob = lli->lli_clob;
int result;
if (S_ISREG(cl_inode_mode(inode))) {
env = cl_env_get(refcheck);
if (!IS_ERR(env)) {
io = ccc_env_thread_io(env);
io->ci_obj = clob;
*envout = env;
*ioout = io;
result = 1;
} else
result = PTR_ERR(env);
} else
result = 0;
return result;
}
int cl_glimpse_size0(struct inode *inode, int agl)
{
/*
* We don't need ast_flags argument to cl_glimpse_size(), because
* osc_lock_enqueue() takes care of the possible deadlock that said
* argument was introduced to avoid.
*/
/*
* XXX but note that ll_file_seek() passes LDLM_FL_BLOCK_NOWAIT to
* cl_glimpse_size(), which doesn't make sense: glimpse locks are not
* blocking anyway.
*/
struct lu_env *env = NULL;
struct cl_io *io = NULL;
int result;
int refcheck;
result = cl_io_get(inode, &env, &io, &refcheck);
if (result > 0) {
again:
io->ci_verify_layout = 1;
result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
if (result > 0)
/*
* nothing to do for this io. This currently happens
* when stripe sub-object's are not yet created.
*/
result = io->ci_result;
else if (result == 0)
result = cl_glimpse_lock(env, io, inode, io->ci_obj,
agl);
OBD_FAIL_TIMEOUT(OBD_FAIL_GLIMPSE_DELAY, 2);
cl_io_fini(env, io);
if (unlikely(io->ci_need_restart))
goto again;
cl_env_put(env, &refcheck);
}
return result;
}
int cl_local_size(struct inode *inode)
{
struct lu_env *env = NULL;
struct cl_io *io = NULL;
struct ccc_thread_info *cti;
struct cl_object *clob;
struct cl_lock_descr *descr;
struct cl_lock *lock;
int result;
int refcheck;
if (!cl_i2info(inode)->lli_has_smd)
return 0;
result = cl_io_get(inode, &env, &io, &refcheck);
if (result <= 0)
return result;
clob = io->ci_obj;
result = cl_io_init(env, io, CIT_MISC, clob);
if (result > 0)
result = io->ci_result;
else if (result == 0) {
cti = ccc_env_info(env);
descr = &cti->cti_descr;
*descr = whole_file;
descr->cld_obj = clob;
lock = cl_lock_peek(env, io, descr, "localsize", current);
if (lock) {
cl_merge_lvb(env, inode);
cl_unuse(env, lock);
cl_lock_release(env, lock, "localsize", current);
result = 0;
} else
result = -ENODATA;
}
cl_io_fini(env, io);
cl_env_put(env, &refcheck);
return result;
}
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