--- /dev/null
+/*
+ * 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 != NULL)
+ 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 == NULL)
+ 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 != NULL) {
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff