*
* 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.
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
* GPL HEADER END
*/
* Copyright 2008 Sun Microsystems, Inc. All rights reserved
* Use is subject to license terms.
*
- * Copyright (c) 2012, Intel Corporation.
+ * Copyright (c) 2014 Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Lustre is a trademark of Sun Microsystems, Inc.
*
- * lustre/ofd/filter_fmd.c
+ * lustre/ofd/ofd_fmd.c
+ *
+ * This file provides functions to handle Filter Modification Data (FMD).
+ * The FMD is responsible for file attributes to be applied in
+ * Transaction ID (XID) order, so older requests can't re-write newer
+ * attributes.
+ *
+ * FMD is organized as per-client list and identified by FID of object. Each
+ * FMD stores FID of object and the highest received XID of modification
+ * request for this object.
+ *
+ * FMD can expire if there are no updates for a long time to keep the list
+ * reasonably small.
+ *
+ * Author: Andreas Dilger <andreas.dilger@intel.com>
*/
#define DEBUG_SUBSYSTEM S_FILTER
#include "ofd_internal.h"
-static cfs_mem_cache_t *ll_fmd_cachep;
+static struct kmem_cache *ll_fmd_cachep;
-/* drop fmd reference, free it if last ref. must be called with fed_lock held.*/
+/**
+ * Drop FMD reference and free it if reference drops to zero.
+ *
+ * Must be called with fed_lock held.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fmd FMD to put
+ */
static inline void ofd_fmd_put_nolock(struct obd_export *exp,
struct ofd_mod_data *fmd)
{
struct filter_export_data *fed = &exp->exp_filter_data;
- LASSERT_SPIN_LOCKED(&fed->fed_lock);
+ assert_spin_locked(&fed->fed_lock);
if (--fmd->fmd_refcount == 0) {
/* XXX when we have persistent reservations and the handle
* is stored herein we need to drop it here. */
fed->fed_mod_count--;
- cfs_list_del(&fmd->fmd_list);
+ list_del(&fmd->fmd_list);
OBD_SLAB_FREE(fmd, ll_fmd_cachep, sizeof(*fmd));
}
}
-/* drop fmd reference, free it if last ref */
+/**
+ * Wrapper to drop FMD reference with fed_lock held.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fmd FMD to put
+ */
void ofd_fmd_put(struct obd_export *exp, struct ofd_mod_data *fmd)
{
struct filter_export_data *fed = &exp->exp_filter_data;
spin_unlock(&fed->fed_lock);
}
-/* expire entries from the end of the list if there are too many
- * or they are too old */
+/**
+ * Expire FMD entries.
+ *
+ * Expire entries from the FMD list if there are too many
+ * of them or they are too old.
+ *
+ * This function must be called with fed_lock held.
+ *
+ * The \a keep FMD is not to be expired in any case. This parameter is used
+ * by ofd_fmd_find_nolock() to prohibit a FMD that was just found from
+ * expiring.
+ *
+ * \param[in] exp OBD export
+ * \param[in] keep FMD to keep always
+ */
static void ofd_fmd_expire_nolock(struct obd_export *exp,
struct ofd_mod_data *keep)
{
cfs_time_t now = cfs_time_current();
- cfs_list_for_each_entry_safe(fmd, tmp, &fed->fed_mod_list, fmd_list) {
+ list_for_each_entry_safe(fmd, tmp, &fed->fed_mod_list, fmd_list) {
if (fmd == keep)
break;
fed->fed_mod_count < ofd->ofd_fmd_max_num)
break;
- cfs_list_del_init(&fmd->fmd_list);
+ list_del_init(&fmd->fmd_list);
ofd_fmd_put_nolock(exp, fmd); /* list reference */
}
}
+/**
+ * Expire FMD entries.
+ *
+ * This is a wrapper to call ofd_fmd_expire_nolock() with the required lock.
+ *
+ * \param[in] exp OBD export
+ */
void ofd_fmd_expire(struct obd_export *exp)
{
struct filter_export_data *fed = &exp->exp_filter_data;
spin_unlock(&fed->fed_lock);
}
-/* find specified fid in fed_fmd_list.
- * caller must hold fed_lock and take fmd reference itself */
+/**
+ * Find FMD by specified FID.
+ *
+ * Function finds FMD entry by FID in the filter_export_data::fed_fmd_list.
+ *
+ * Caller must hold filter_export_data::fed_lock and take FMD reference.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fid FID of FMD to find
+ *
+ * \retval struct ofd_mod_data found by FID
+ * \retval NULL is FMD is not found
+ */
static struct ofd_mod_data *ofd_fmd_find_nolock(struct obd_export *exp,
const struct lu_fid *fid)
{
cfs_time_t now = cfs_time_current();
- LASSERT_SPIN_LOCKED(&fed->fed_lock);
+ assert_spin_locked(&fed->fed_lock);
- cfs_list_for_each_entry_reverse(fmd, &fed->fed_mod_list, fmd_list) {
+ list_for_each_entry_reverse(fmd, &fed->fed_mod_list, fmd_list) {
if (lu_fid_eq(&fmd->fmd_fid, fid)) {
found = fmd;
- cfs_list_del(&fmd->fmd_list);
- cfs_list_add_tail(&fmd->fmd_list, &fed->fed_mod_list);
+ list_del(&fmd->fmd_list);
+ list_add_tail(&fmd->fmd_list, &fed->fed_mod_list);
fmd->fmd_expire = cfs_time_add(now, ofd->ofd_fmd_max_age);
break;
}
return found;
}
-/* Find fmd based on fid or return NULL if not found. */
+/**
+ * Find FMD by specified FID with locking.
+ *
+ * Wrapper to the ofd_fmd_find_nolock() with correct locks.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fid FID of FMD to find
+ *
+ * \retval struct ofd_mod_data found by FID
+ * \retval NULL indicates FMD is not found
+ */
struct ofd_mod_data *ofd_fmd_find(struct obd_export *exp,
- struct lu_fid *fid)
+ const struct lu_fid *fid)
{
struct filter_export_data *fed = &exp->exp_filter_data;
struct ofd_mod_data *fmd;
return fmd;
}
-/* Find fmd based on FID, or create a new one if none is found.
+/**
+ * Find FMD by FID or create a new one if none is found.
+ *
* It is possible for this function to return NULL under memory pressure,
- * or if fid = 0 is passed (which will only cause old entries to expire).
- * Currently this is not fatal because any fmd state is transient and
- * may also be freed when it gets sufficiently old. */
-struct ofd_mod_data *ofd_fmd_get(struct obd_export *exp, struct lu_fid *fid)
+ * or if the passed FID is zero (which will only cause old entries to expire).
+ * Currently this is not fatal because any FMD state is transient and
+ * may also be freed when it gets sufficiently old.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fid FID of FMD to find
+ *
+ * \retval struct ofd_mod_data found by FID
+ * \retval NULL indicates FMD is not found
+ */
+struct ofd_mod_data *ofd_fmd_get(struct obd_export *exp, const struct lu_fid *fid)
{
struct filter_export_data *fed = &exp->exp_filter_data;
struct ofd_device *ofd = ofd_exp(exp);
found = ofd_fmd_find_nolock(exp, fid);
if (fmd_new) {
if (found == NULL) {
- cfs_list_add_tail(&fmd_new->fmd_list,
- &fed->fed_mod_list);
+ list_add_tail(&fmd_new->fmd_list,
+ &fed->fed_mod_list);
fmd_new->fmd_fid = *fid;
fmd_new->fmd_refcount++; /* list reference */
found = fmd_new;
}
#ifdef DO_FMD_DROP
-/* drop fmd list reference so it will disappear when last reference is put.
- * This isn't so critical because it would in fact only affect the one client
- * that is doing the unlink and at worst we have an stale entry referencing
- * an object that should never be used again. */
-void ofd_fmd_drop(struct obd_export *exp, struct lu_fid *fid)
+/**
+ * Drop FMD list reference so it will disappear when last reference is dropped
+ * to zero.
+ *
+ * This function is called from ofd_object_destroy() and may only affect
+ * the one client that is doing the unlink and at worst we have an stale entry
+ * referencing an object that should never be used again.
+ *
+ * NB: this function is used only if DO_FMD_DROP is defined. It is not
+ * currently defined, so FMD drop doesn't happen and FMD are dropped only
+ * when expired.
+ *
+ * \param[in] exp OBD export
+ * \param[in] fid FID of FMD to drop
+ */
+void ofd_fmd_drop(struct obd_export *exp, const struct lu_fid *fid)
{
struct filter_export_data *fed = &exp->exp_filter_data;
struct ofd_mod_data *found = NULL;
spin_lock(&fed->fed_lock);
found = ofd_fmd_find_nolock(exp, fid);
if (found) {
- cfs_list_del_init(&found->fmd_list);
+ list_del_init(&found->fmd_list);
ofd_fmd_put_nolock(exp, found);
}
spin_unlock(&fed->fed_lock);
}
#endif
-/* remove all entries from fmd list */
+/**
+ * Remove all entries from FMD list.
+ *
+ * Cleanup function to free all FMD enries on the given export.
+ *
+ * \param[in] exp OBD export
+ */
void ofd_fmd_cleanup(struct obd_export *exp)
{
struct filter_export_data *fed = &exp->exp_filter_data;
struct ofd_mod_data *fmd = NULL, *tmp;
spin_lock(&fed->fed_lock);
- cfs_list_for_each_entry_safe(fmd, tmp, &fed->fed_mod_list, fmd_list) {
- cfs_list_del_init(&fmd->fmd_list);
+ list_for_each_entry_safe(fmd, tmp, &fed->fed_mod_list, fmd_list) {
+ list_del_init(&fmd->fmd_list);
if (fmd->fmd_refcount > 1) {
CDEBUG(D_INFO, "fmd %p still referenced (refcount = %d)\n",
fmd, fmd->fmd_refcount);
spin_unlock(&fed->fed_lock);
}
+/**
+ * Initialize FMD subsystem.
+ *
+ * This function is called upon OFD setup and initialize memory to be used
+ * by FMD entries.
+ */
int ofd_fmd_init(void)
{
- ll_fmd_cachep = cfs_mem_cache_create("ll_fmd_cache",
- sizeof(struct ofd_mod_data),
- 0, 0);
+ ll_fmd_cachep = kmem_cache_create("ll_fmd_cache",
+ sizeof(struct ofd_mod_data),
+ 0, 0, NULL);
if (!ll_fmd_cachep)
return -ENOMEM;
else
return 0;
}
+/**
+ * Stop FMD subsystem.
+ *
+ * This function is called upon OFD cleanup and destroy memory used
+ * by FMD entries.
+ */
void ofd_fmd_exit(void)
{
if (ll_fmd_cachep) {
- int rc = cfs_mem_cache_destroy(ll_fmd_cachep);
-
- LASSERTF(rc == 0, "Cannot destroy ll_fmd_cachep: rc %d\n", rc);
+ kmem_cache_destroy(ll_fmd_cachep);
ll_fmd_cachep = NULL;
}
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff