Viewing: mdd_trans.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2011, 2017, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Lustre Metadata Server (mdd) routines
*
* Author: Wang Di <wangdi@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_MDS
#include <linux/kthread.h>
#include <obd_class.h>
#include <lprocfs_status.h>
#include <lustre_mds.h>
#include <lustre_barrier.h>
#include "mdd_internal.h"
struct thandle *mdd_trans_create(const struct lu_env *env,
struct mdd_device *mdd)
{
struct thandle *th;
struct lu_ucred *uc = lu_ucred_check(env);
/* If blocked by the write barrier, then return "-EINPROGRESS"
* to the caller. Usually, such error will be forwarded to the
* client, and the expected behaviour is to re-try such modify
* RPC some time later until the barrier is thawed or expired. */
if (unlikely(!barrier_entry(mdd->mdd_bottom)))
return ERR_PTR(-EINPROGRESS);
if (mdd->mdd_child->dd_rdonly)
return ERR_PTR(-EROFS);
th = mdd_child_ops(mdd)->dt_trans_create(env, mdd->mdd_child);
if (IS_ERR(th)) {
barrier_exit(mdd->mdd_bottom);
goto out;
}
if (uc)
th->th_ignore_quota = !!cap_raised(uc->uc_cap, CAP_SYS_RESOURCE);
th->th_ignore_root_proj_quota =
uc ? uc->uc_rbac_ignore_root_prjquota : 1;
out:
mdd_env_info(env)->mdi_chlog_declared = 0;
return th;
}
int mdd_trans_start(const struct lu_env *env, struct mdd_device *mdd,
struct thandle *th)
{
return mdd_child_ops(mdd)->dt_trans_start(env, mdd->mdd_child, th);
}
struct mdd_changelog_gc {
struct mdd_device *mcgc_mdd;
__u32 mcgc_id;
__u32 mcgc_mintime;
__u64 mcgc_minrec;
char mcgc_name[CHANGELOG_USER_NAMELEN_FULL];
};
/* return first registered ChangeLog user idle since too long
* use ChangeLog's user plain LLOG mtime for this */
static int mdd_changelog_gc_cb(const struct lu_env *env,
struct llog_handle *llh,
struct llog_rec_hdr *hdr, void *data)
{
struct llog_changelog_user_rec2 *rec;
struct mdd_changelog_gc *mcgc = data;
struct mdd_device *mdd = mcgc->mcgc_mdd;
ENTRY;
if ((llh->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN) == 0)
RETURN(-ENXIO);
rec = container_of(hdr, typeof(*rec), cur_hdr);
if (rec->cur_endrec < mcgc->mcgc_minrec &&
(mdd->mdd_changelog_emrg_gc ||
mdd_changelog_is_too_idle(mdd, rec->cur_endrec, rec->cur_time))) {
mcgc->mcgc_mintime = rec->cur_time;
mcgc->mcgc_minrec = rec->cur_endrec;
mcgc->mcgc_id = rec->cur_id;
mdd_chlg_username(rec, mcgc->mcgc_name,
sizeof(mcgc->mcgc_name));
}
RETURN(0);
}
/* recover space from long-term inactive ChangeLog users */
static int mdd_chlg_garbage_collect(void *data)
{
struct mdd_device *mdd = data;
struct lu_env *env = NULL;
int rc;
struct llog_ctxt *ctxt, *uctxt;
ENTRY;
mdd->mdd_cl.mc_gc_task = current;
CDEBUG(D_HA, "%s: ChangeLog garbage collect thread start with PID %d\n",
mdd2obd_dev(mdd)->obd_name, current->pid);
OBD_ALLOC_PTR(env);
if (!env)
GOTO(out, rc = -ENOMEM);
rc = lu_env_init(env, LCT_MD_THREAD);
if (rc)
GOTO(out_free, rc);
uctxt = llog_get_context(mdd2obd_dev(mdd),
LLOG_CHANGELOG_USER_ORIG_CTXT);
if (!uctxt)
GOTO(out_env, rc = -ENXIO);
if (!(uctxt->loc_handle->lgh_hdr->llh_flags & LLOG_F_IS_CAT))
GOTO(out_uctxt, rc = -ENXIO);
ctxt = llog_get_context(mdd2obd_dev(mdd), LLOG_CHANGELOG_ORIG_CTXT);
if (!ctxt)
GOTO(out_uctxt, rc = -ENXIO);
for (;;) {
__u32 time_now = (__u32)ktime_get_real_seconds();
struct mdd_changelog_gc mcgc = {
.mcgc_mdd = mdd,
.mcgc_minrec = mdd->mdd_cl.mc_index,
.mcgc_name = { 0 },
};
/* Prior each iteration check if emergency GC is still needed */
if (mdd->mdd_changelog_emrg_gc &&
mdd_changelog_is_space_safe(env, mdd, ctxt->loc_handle, 0))
mdd->mdd_changelog_emrg_gc = false;
rc = llog_cat_process(env, uctxt->loc_handle,
mdd_changelog_gc_cb, &mcgc, 0, 0);
if (rc)
GOTO(out_ctxt, rc);
if (!mcgc.mcgc_name[0])
break;
CWARN("%s: force deregister of changelog user %s idle for %us with %llu unprocessed records\n",
mdd2obd_dev(mdd)->obd_name, mcgc.mcgc_name,
time_now - mcgc.mcgc_mintime,
mdd->mdd_cl.mc_index - mcgc.mcgc_minrec);
mdd_changelog_user_purge(env, mdd, mcgc.mcgc_id);
/* purge just the oldest user in emergency per GC run */
mdd->mdd_changelog_emrg_gc = false;
if (kthread_should_stop())
GOTO(out_ctxt, rc = 0);
}
EXIT;
out_ctxt:
llog_ctxt_put(ctxt);
out_uctxt:
llog_ctxt_put(uctxt);
out_env:
lu_env_fini(env);
out_free:
OBD_FREE_PTR(env);
out:
spin_lock(&mdd->mdd_cl.mc_lock);
mdd->mdd_cl.mc_gc_task = MDD_CHLG_GC_NONE;
spin_unlock(&mdd->mdd_cl.mc_lock);
return rc;
}
int mdd_trans_stop(const struct lu_env *env, struct mdd_device *mdd,
int result, struct thandle *handle)
{
int rc;
handle->th_result = result;
rc = mdd_child_ops(mdd)->dt_trans_stop(env, mdd->mdd_child, handle);
barrier_exit(mdd->mdd_bottom);
/* bottom half of changelog garbage-collection mechanism, started
* from mdd_changelog_store(). This is required, as running a
* kthead can't occur during a journal transaction is being filled
* because otherwise a deadlock can happen if memory reclaim is
* triggered by kthreadd when forking the new thread, and thus
* I/Os could be attempted to the same device from shrinkers
* requiring a new journal transaction to be started when current
* could never complete (LU-10680).
*/
if (unlikely(mdd->mdd_cl.mc_flags & CLM_ON &&
cmpxchg(&mdd->mdd_cl.mc_gc_task, MDD_CHLG_GC_NEED,
MDD_CHLG_GC_START) == MDD_CHLG_GC_NEED)) {
/* XXX we may want to cmpxchg() only if MDD_CHLG_GC_NEED
* to save its cost in the frequent case and have an extra
* if/test cost in the rare case where we need to spawn?
*/
struct task_struct *gc_task;
struct obd_device *obd = mdd2obd_dev(mdd);
gc_task = kthread_run(mdd_chlg_garbage_collect, mdd,
"chlg_gc_thread");
if (IS_ERR(gc_task)) {
CERROR("%s: cannot start ChangeLog garbage collection thread: rc = %ld\n",
obd->obd_name,
PTR_ERR(gc_task));
mdd->mdd_cl.mc_gc_task = MDD_CHLG_GC_NONE;
} else {
CDEBUG(D_HA, "%s: a ChangeLog garbage collection thread has been started\n",
obd->obd_name);
}
}
/* if operation failed, return \a result, otherwise return status of
* dt_trans_stop */
return result ?: rc;
}
