* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
- * Copyright (c) 2011, 2014, Intel Corporation.
+ * Copyright (c) 2011, 2017, 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).
+ * glimpse code used by vvp (and other Lustre clients in the future).
*
* Author: Nikita Danilov <nikita.danilov@sun.com>
* Author: Oleg Drokin <oleg.drokin@sun.com>
#include "vvp_internal.h"
static const struct cl_lock_descr whole_file = {
- .cld_start = 0,
- .cld_end = CL_PAGE_EOF,
- .cld_mode = CLM_READ
+ .cld_start = 0,
+ .cld_end = CL_PAGE_EOF,
+ .cld_mode = CLM_READ
};
/*
*/
blkcnt_t dirty_cnt(struct inode *inode)
{
- blkcnt_t cnt = 0;
+ blkcnt_t cnt = 0;
struct vvp_object *vob = cl_inode2vvp(inode);
- void *results[1];
+ 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 (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->vob_mmap_cnt) > 0)
cnt = 1;
- return (cnt > 0) ? 1 : 0;
+ return (cnt > 0) ? 1 : 0;
}
int cl_glimpse_lock(const struct lu_env *env, struct cl_io *io,
CDEBUG(D_DLMTRACE, "Glimpsing inode "DFID"\n", PFID(fid));
/* NOTE: this looks like DLM lock request, but it may
- * not be one. Due to CEF_ASYNC flag (translated
+ * not be one. Due to CEF_GLIMPSE flag (translated
* to LDLM_FL_HAS_INTENT by osc), this is
* glimpse request, that won't revoke any
* conflicting DLM locks held. Instead,
*descr = whole_file;
descr->cld_obj = clob;
descr->cld_mode = CLM_READ;
- descr->cld_enq_flags = CEF_ASYNC | CEF_MUST;
+ descr->cld_enq_flags = CEF_GLIMPSE | CEF_MUST;
if (agl)
- descr->cld_enq_flags |= CEF_AGL;
+ descr->cld_enq_flags |= CEF_SPECULATIVE | CEF_NONBLOCK;
/*
- * 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.
*/
RETURN(result);
}
-static int cl_io_get(struct inode *inode, struct lu_env **envout,
- struct cl_io **ioout, __u16 *refcheck)
+/**
+ * Get an IO environment for special operations such as glimpse locks and
+ * manually requested locks (ladvise lockahead)
+ *
+ * \param[in] inode inode the operation is being performed on
+ * \param[out] envout thread specific execution environment
+ * \param[out] ioout client io description
+ * \param[out] refcheck reference check
+ *
+ * \retval 1 on success
+ * \retval 0 not a regular file, cannot get environment
+ * \retval negative negative errno on error
+ */
+int cl_io_get(struct inode *inode, struct lu_env **envout,
+ struct cl_io **ioout, u16 *refcheck)
{
- struct lu_env *env;
- struct cl_io *io;
- struct ll_inode_info *lli = ll_i2info(inode);
- struct cl_object *clob = lli->lli_clob;
+ 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)) {
+ 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;
+ 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;
- __u16 refcheck;
- int result;
-
- ENTRY;
-
- 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);
+ /*
+ * 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;
+ u16 refcheck;
+ int retried = 0;
+ int result;
+
+ ENTRY;
+
+ result = cl_io_get(inode, &env, &io, &refcheck);
+ if (result <= 0)
+ RETURN(result);
+
+ do {
+ io->ci_ndelay_tried = retried++;
+ io->ci_ndelay = io->ci_verify_layout = 1;
+ result = cl_io_init(env, io, CIT_GLIMPSE, 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);
+ if (!agl && result == -EWOULDBLOCK)
+ io->ci_need_restart = 1;
+ }
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);
- }
+ cl_io_fini(env, io);
+ } while (unlikely(io->ci_need_restart));
+
+ cl_env_put(env, &refcheck);
RETURN(result);
}