diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/llite/glimpse.c')
-rw-r--r-- | drivers/staging/lustre/lustre/llite/glimpse.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/llite/glimpse.c b/drivers/staging/lustre/lustre/llite/glimpse.c new file mode 100644 index 000000000000..d8ea75424e2f --- /dev/null +++ b/drivers/staging/lustre/lustre/llite/glimpse.c @@ -0,0 +1,255 @@ +/* + * 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 "../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 vvp_object *vob = cl_inode2vvp(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->vob_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 ll_inode_info *lli = ll_i2info(inode); + const struct lu_fid *fid = lu_object_fid(&clob->co_lu); + 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) { + struct cl_lock *lock = vvp_env_lock(env); + struct cl_lock_descr *descr = &lock->cll_descr; + + /* 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_READ; + descr->cld_enq_flags = CEF_ASYNC | CEF_MUST; + if (agl) + descr->cld_enq_flags |= CEF_AGL; + /* + * 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. + */ + result = cl_lock_request(env, io, lock); + if (result < 0) + return result; + + if (!agl) { + ll_merge_attr(env, inode); + if (i_size_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_lock_release(env, lock); + } else { + CDEBUG(D_DLMTRACE, "No objects for inode\n"); + ll_merge_attr(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 ll_inode_info *lli = ll_i2info(inode); + struct cl_object *clob = lli->lli_clob; + int result; + + if (S_ISREG(inode->i_mode)) { + env = cl_env_get(refcheck); + if (!IS_ERR(env)) { + io = vvp_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 cl_object *clob; + int result; + int refcheck; + + if (!ll_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) { + struct cl_lock *lock = vvp_env_lock(env); + + lock->cll_descr = whole_file; + lock->cll_descr.cld_enq_flags = CEF_PEEK; + lock->cll_descr.cld_obj = clob; + result = cl_lock_request(env, io, lock); + if (result == 0) { + ll_merge_attr(env, inode); + cl_lock_release(env, lock); + } + } + cl_io_fini(env, io); + cl_env_put(env, &refcheck); + return result; +} |