* 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 COPYING file that accompanied this code.
-
+ *
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* Copyright 2009 Sun Microsystems, Inc. All rights reserved
* Use is subject to license terms.
*
- * Copyright (c) 2012, 2013, Intel Corporation.
+ * Copyright (c) 2012, 2014, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* lustre/lod/lod_qos.c
*
+ * Implementation of different allocation algorithm used
+ * to distribute objects and data among OSTs.
*/
#define DEBUG_SUBSYSTEM S_LOV
#define D_QOS D_OTHER
-#if 0
-#define QOS_DEBUG(fmt, ...) CDEBUG(D_OTHER, fmt, ## __VA_ARGS__)
-#define QOS_CONSOLE(fmt, ...) LCONSOLE(D_OTHER, fmt, ## __VA_ARGS__)
-#else
-#define QOS_DEBUG(fmt, ...)
-#define QOS_CONSOLE(fmt, ...)
-#endif
+#define QOS_DEBUG(fmt, ...) CDEBUG(D_QOS, fmt, ## __VA_ARGS__)
+#define QOS_CONSOLE(fmt, ...) LCONSOLE(D_QOS, fmt, ## __VA_ARGS__)
#define TGT_BAVAIL(i) (OST_TGT(lod,i)->ltd_statfs.os_bavail * \
OST_TGT(lod,i)->ltd_statfs.os_bsize)
+/**
+ * Add a new target to Quality of Service (QoS) target table.
+ *
+ * Add a new OST target to the structure representing an OSS. Resort the list
+ * of known OSSs by the number of OSTs attached to each OSS. The OSS list is
+ * protected internally and no external locking is required.
+ *
+ * \param[in] lod LOD device
+ * \param[in] ost_desc OST description
+ *
+ * \retval 0 on success
+ * \retval -ENOMEM on error
+ */
int qos_add_tgt(struct lod_device *lod, struct lod_tgt_desc *ost_desc)
{
struct lod_qos_oss *oss = NULL, *temposs;
struct obd_export *exp = ost_desc->ltd_exp;
int rc = 0, found = 0;
- cfs_list_t *list;
+ struct list_head *list;
ENTRY;
down_write(&lod->lod_qos.lq_rw_sem);
* but there is no official API to access information like this
* with OSD API.
*/
- cfs_list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
+ list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
if (obd_uuid_equals(&oss->lqo_uuid,
&exp->exp_connection->c_remote_uuid)) {
found++;
sizeof(oss->lqo_uuid));
} else {
/* Assume we have to move this one */
- cfs_list_del(&oss->lqo_oss_list);
+ list_del(&oss->lqo_oss_list);
}
oss->lqo_ost_count++;
/* Add sorted by # of OSTs. Find the first entry that we're
bigger than... */
list = &lod->lod_qos.lq_oss_list;
- cfs_list_for_each_entry(temposs, list, lqo_oss_list) {
+ list_for_each_entry(temposs, list, lqo_oss_list) {
if (oss->lqo_ost_count > temposs->lqo_ost_count)
break;
}
/* ...and add before it. If we're the first or smallest, temposs
points to the list head, and we add to the end. */
- cfs_list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
+ list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
lod->lod_qos.lq_dirty = 1;
lod->lod_qos.lq_rr.lqr_dirty = 1;
RETURN(rc);
}
+/**
+ * Remove OST target from QoS table.
+ *
+ * Removes given OST target from QoS table and releases related OSS structure
+ * if no OSTs remain on the OSS.
+ *
+ * \param[in] lod LOD device
+ * \param[in] ost_desc OST description
+ *
+ * \retval 0 on success
+ * \retval -ENOENT if no OSS was found
+ */
int qos_del_tgt(struct lod_device *lod, struct lod_tgt_desc *ost_desc)
{
struct lod_qos_oss *oss;
if (oss->lqo_ost_count == 0) {
CDEBUG(D_QOS, "removing OSS %s\n",
obd_uuid2str(&oss->lqo_uuid));
- cfs_list_del(&oss->lqo_oss_list);
+ list_del(&oss->lqo_oss_list);
ost_desc->ltd_qos.ltq_oss = NULL;
OBD_FREE_PTR(oss);
}
RETURN(rc);
}
+/**
+ * Check whether the target is available for new OST objects.
+ *
+ * Request statfs data from the given target and verify it's active and not
+ * read-only. If so, then it can be used to place new OST objects. This
+ * function also maintains the number of active/inactive targets and sets
+ * dirty flags if those numbers change so others can run re-balance procedures.
+ * No external locking is required.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] d LOD device
+ * \param[in] index index of OST target to check
+ * \param[out] sfs buffer for statfs data
+ *
+ * \retval 0 if the target is good
+ * \retval negative negated errno on error
+
+ */
static int lod_statfs_and_check(const struct lu_env *env, struct lod_device *d,
int index, struct obd_statfs *sfs)
{
struct lod_tgt_desc *ost;
int rc;
+ ENTRY;
LASSERT(d);
ost = OST_TGT(d,index);
RETURN(rc);
}
+/**
+ * Maintain per-target statfs data.
+ *
+ * The function refreshes statfs data for all the targets every N seconds.
+ * The actual N is controlled via procfs and set to LOV_DESC_QOS_MAXAGE_DEFAULT
+ * initially.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lod LOD device
+ */
static void lod_qos_statfs_update(const struct lu_env *env,
struct lod_device *lod)
{
struct obd_device *obd = lod2obd(lod);
struct ost_pool *osts = &(lod->lod_pool_info);
unsigned int i;
- int idx, rc = 0;
+ int idx;
__u64 max_age, avail;
ENTRY;
down_write(&lod->lod_qos.lq_rw_sem);
if (cfs_time_beforeq_64(max_age, obd->obd_osfs_age))
- GOTO(out, rc = 0);
+ goto out;
for (i = 0; i < osts->op_count; i++) {
idx = osts->op_array[i];
avail = OST_TGT(lod,idx)->ltd_statfs.os_bavail;
- rc = lod_statfs_and_check(env, lod, idx,
- &OST_TGT(lod,idx)->ltd_statfs);
- if (rc)
- break;
+ if (lod_statfs_and_check(env, lod, idx,
+ &OST_TGT(lod, idx)->ltd_statfs))
+ continue;
if (OST_TGT(lod,idx)->ltd_statfs.os_bavail != avail)
/* recalculate weigths */
lod->lod_qos.lq_dirty = 1;
EXIT;
}
-/* Recalculate per-object penalties for OSSs and OSTs,
- depends on size of each ost in an oss */
+/**
+ * Calculate per-OST and per-OSS penalties
+ *
+ * Re-calculate penalties when the configuration changes, active targets
+ * change and after statfs refresh (all these are reflected by lq_dirty flag).
+ * On every OST and OSS: decay the penalty by half for every 8x the update
+ * interval that the device has been idle. That gives lots of time for the
+ * statfs information to be updated (which the penalty is only a proxy for),
+ * and avoids penalizing OSS/OSTs under light load.
+ * See lod_qos_calc_weight() for how penalties are factored into the weight.
+ *
+ * \param[in] lod LOD device
+ *
+ * \retval 0 on success
+ * \retval -EAGAIN the number of OSTs isn't enough
+ */
static int lod_qos_calc_ppo(struct lod_device *lod)
{
struct lod_qos_oss *oss;
GOTO(out, rc = -EAGAIN);
/* find bavail on each OSS */
- cfs_list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list)
- oss->lqo_bavail = 0;
+ list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list)
+ oss->lqo_bavail = 0;
lod->lod_qos.lq_active_oss_count = 0;
/*
age > 32 * lod->lod_desc.ld_qos_maxage)
OST_TGT(lod,i)->ltd_qos.ltq_penalty = 0;
else if (age > lod->lod_desc.ld_qos_maxage)
- /* Decay the penalty by half for every 8x the update
- * interval that the device has been idle. That gives
- * lots of time for the statfs information to be
- * updated (which the penalty is only a proxy for),
- * and avoids penalizing OSS/OSTs under light load. */
+ /* Decay OST penalty. */
OST_TGT(lod,i)->ltd_qos.ltq_penalty >>=
(age / lod->lod_desc.ld_qos_maxage);
}
}
/* Per-OSS penalty is prio * oss_avail / oss_osts / (num_oss - 1) / 2 */
- cfs_list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
+ list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
temp = oss->lqo_bavail >> 1;
do_div(temp, oss->lqo_ost_count * num_active);
oss->lqo_penalty_per_obj = (temp * prio_wide) >> 8;
age > 32 * lod->lod_desc.ld_qos_maxage)
oss->lqo_penalty = 0;
else if (age > lod->lod_desc.ld_qos_maxage)
- /* Decay the penalty by half for every 8x the update
- * interval that the device has been idle. That gives
- * lots of time for the statfs information to be
- * updated (which the penalty is only a proxy for),
- * and avoids penalizing OSS/OSTs under light load. */
+ /* Decay OSS penalty. */
oss->lqo_penalty >>= age / lod->lod_desc.ld_qos_maxage;
}
RETURN(rc);
}
+/**
+ * Calculate weight for a given OST target.
+ *
+ * The final OST weight is the number of bytes available minus the OST and
+ * OSS penalties. See lod_qos_calc_ppo() for how penalties are calculated.
+ *
+ * \param[in] lod LOD device, where OST targets are listed
+ * \param[in] i OST target index
+ *
+ * \retval 0
+ */
static int lod_qos_calc_weight(struct lod_device *lod, int i)
{
__u64 temp, temp2;
- /* Final ost weight = TGT_BAVAIL - ost_penalty - oss_penalty */
temp = TGT_BAVAIL(i);
temp2 = OST_TGT(lod,i)->ltd_qos.ltq_penalty +
OST_TGT(lod,i)->ltd_qos.ltq_oss->lqo_penalty;
return 0;
}
-/* We just used this index for a stripe; adjust everyone's weights */
+/**
+ * Re-calculate weights.
+ *
+ * The function is called when some OST target was used for a new object. In
+ * this case we should re-calculate all the weights to keep new allocations
+ * balanced well.
+ *
+ * \param[in] lod LOD device
+ * \param[in] osts OST pool where a new object was placed
+ * \param[in] index OST target where a new object was placed
+ * \param[out] total_wt new total weight for the pool
+ *
+ * \retval 0
+ */
static int lod_qos_used(struct lod_device *lod, struct ost_pool *osts,
__u32 index, __u64 *total_wt)
{
lod->lod_qos.lq_active_oss_count;
/* Decrease all OSS penalties */
- cfs_list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
+ list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
if (oss->lqo_penalty < oss->lqo_penalty_per_obj)
oss->lqo_penalty = 0;
else
}
#define LOV_QOS_EMPTY ((__u32)-1)
-/* compute optimal round-robin order, based on OSTs per OSS */
+
+/**
+ * Calculate optimal round-robin order with regard to OSSes.
+ *
+ * Place all the OSTs from pool \a src_pool in a special array to be used for
+ * round-robin (RR) stripe allocation. The placement algorithm interleaves
+ * OSTs from the different OSSs so that RR allocation can balance OSSs evenly.
+ * Resorts the targets when the number of active targets changes (because of
+ * a new target or activation/deactivation).
+ *
+ * \param[in] lod LOD device
+ * \param[in] src_pool OST pool
+ * \param[in] lqr round-robin list
+ *
+ * \retval 0 on success
+ * \retval -ENOMEM fails to allocate the array
+ */
static int lod_qos_calc_rr(struct lod_device *lod, struct ost_pool *src_pool,
struct lod_qos_rr *lqr)
{
/* Place all the OSTs from 1 OSS at the same time. */
placed = 0;
- cfs_list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
+ list_for_each_entry(oss, &lod->lod_qos.lq_oss_list, lqo_oss_list) {
int j = 0;
for (i = 0; i < lqr->lqr_pool.op_count; i++) {
}
/**
- * A helper function to:
- * create in-core lu object on the specified OSP
- * declare creation of the object
- * IMPORTANT: at this stage object is anonymouos - it has no fid assigned
- * this is a workaround till we have natural FIDs on OST
- *
- * at this point we want to declare (reserve) object for us as
- * we can't block at execution (when create method is called).
- * otherwise we'd block whole transaction batch
+ * Instantiate and declare creation of a new object.
+ *
+ * The function instantiates LU representation for a new object on the
+ * specified device. Also it declares an intention to create that
+ * object on the storage target.
+ *
+ * Note lu_object_anon() is used which is a trick with regard to LU/OSD
+ * infrastructure - in the existing precreation framework we can't assign FID
+ * at this moment, we do this later once a transaction is started. So the
+ * special method instantiates FID-less object in the cache and later it
+ * will get a FID and proper placement in LU cache.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] d LOD device
+ * \param[in] ost_idx OST target index where the object is being created
+ * \param[in] th transaction handle
+ *
+ * \retval object ptr on success, ERR_PTR() otherwise
*/
static struct dt_object *lod_qos_declare_object_on(const struct lu_env *env,
struct lod_device *d,
dt = container_of(n, struct dt_object, do_lu);
- rc = dt_declare_create(env, dt, NULL, NULL, NULL, th);
- if (rc) {
+ rc = lod_sub_object_declare_create(env, dt, NULL, NULL, NULL, th);
+ if (rc < 0) {
CDEBUG(D_OTHER, "can't declare creation on #%u: %d\n",
ost_idx, rc);
lu_object_put(env, o);
RETURN(dt);
}
+/**
+ * Calculate a minimum acceptable stripe count.
+ *
+ * Return an acceptable stripe count depending on flag LOV_USES_DEFAULT_STRIPE:
+ * all stripes or 3/4 of stripes.
+ *
+ * \param[in] stripe_cnt number of stripes requested
+ * \param[in] flags 0 or LOV_USES_DEFAULT_STRIPE
+ *
+ * \retval acceptable stripecount
+ */
static int min_stripe_count(__u32 stripe_cnt, int flags)
{
return (flags & LOV_USES_DEFAULT_STRIPE ?
#define LOV_CREATE_RESEED_MULT 30
#define LOV_CREATE_RESEED_MIN 2000
+/**
+ * Check if an OST is full.
+ *
+ * Check whether an OST should be considered full based
+ * on the given statfs data.
+ *
+ * \param[in] msfs statfs data
+ *
+ * \retval false not full
+ * \retval true full
+ */
static int inline lod_qos_dev_is_full(struct obd_statfs *msfs)
{
__u64 used;
return (msfs->os_bavail < used);
}
+/**
+ * Initialize temporary OST-in-use array.
+ *
+ * Allocate or extend the array used to mark targets already assigned to a new
+ * striping so they are not used more than once.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] stripes number of items needed in the array
+ *
+ * \retval 0 on success
+ * \retval -ENOMEM on error
+ */
static inline int lod_qos_ost_in_use_clear(const struct lu_env *env,
__u32 stripes)
{
return 0;
}
-static inline void lod_qos_ost_in_use(const struct lu_env *env, int idx, int ost)
+/**
+ * Remember a target in the array of used targets.
+ *
+ * Mark the given target as used for a new striping being created. The status
+ * of an OST in a striping can be checked with lod_qos_is_ost_used().
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] idx index in the array
+ * \param[in] ost OST target index to mark as used
+ */
+static inline void lod_qos_ost_in_use(const struct lu_env *env,
+ int idx, int ost)
{
struct lod_thread_info *info = lod_env_info(env);
int *osts = info->lti_ea_store;
osts[idx] = ost;
}
+/**
+ * Check is OST used in a striping.
+ *
+ * Checks whether OST with the given index is marked as used in the temporary
+ * array (see lod_qos_ost_in_use()).
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] ost OST target index to check
+ * \param[in] stripes the number of items used in the array already
+ *
+ * \retval 0 not used
+ * \retval 1 used
+ */
static int lod_qos_is_ost_used(const struct lu_env *env, int ost, __u32 stripes)
{
struct lod_thread_info *info = lod_env_info(env);
return 0;
}
-/* Allocate objects on OSTs with round-robin algorithm */
+/**
+ * Allocate a striping using round-robin algorigthm.
+ *
+ * Allocates a new striping using round-robin algorithm. The function refreshes
+ * all the internal structures (statfs cache, array of available OSTs sorted
+ * with regard to OSS, etc). The number of stripes required is taken from the
+ * object (must be prepared by the caller), but can change if the flag
+ * LOV_USES_DEFAULT_STRIPE is supplied. The caller should ensure nobody else
+ * is trying to create a striping on the object in parallel. All the internal
+ * structures (like pools, etc) are protected and no additional locking is
+ * required. The function succeeds even if a single stripe is allocated. To save
+ * time we give priority to targets which already have objects precreated.
+ * Full OSTs are skipped (see lod_qos_dev_is_full() for the details).
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[out] stripe striping created
+ * \param[in] flags allocation flags (0 or LOV_USES_DEFAULT_STRIPE)
+ * \param[in] th transaction handle
+ *
+ * \retval 0 on success
+ * \retval -ENOSPC if not enough OSTs are found
+ * \retval negative negated errno for other failures
+ */
static int lod_alloc_rr(const struct lu_env *env, struct lod_object *lo,
struct dt_object **stripe, int flags,
struct thandle *th)
RETURN(rc);
}
-/* alloc objects on osts with specific stripe offset */
+/**
+ * Allocate a specific striping layout on a user defined set of OSTs.
+ *
+ * Allocates new striping using the OST index range provided by the data from
+ * the lmm_obejcts contained in the lov_user_md passed to this method. Full
+ * OSTs are not considered. The exact order of OSTs requested by the user
+ * is respected as much as possible depending on OST status. The number of
+ * stripes needed and stripe offset are taken from the object. If that number
+ * can not be met, then the function returns a failure and then it's the
+ * caller's responsibility to release the stripes allocated. All the internal
+ * structures are protected, but no concurrent allocation is allowed on the
+ * same objects.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[out] stripe striping created
+ * \param[in] lum stripe md to specify list of OSTs
+ * \param[in] th transaction handle
+ *
+ * \retval 0 on success
+ * \retval -ENODEV OST index does not exist on file system
+ * \retval -EINVAL requested OST index is invalid
+ * \retval negative negated errno on error
+ */
+static int lod_alloc_ost_list(const struct lu_env *env,
+ struct lod_object *lo, struct dt_object **stripe,
+ struct lov_user_md *lum, struct thandle *th)
+{
+ struct lod_device *m = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+ struct obd_statfs *sfs = &lod_env_info(env)->lti_osfs;
+ struct dt_object *o;
+ struct lov_user_md_v3 *v3;
+ unsigned int array_idx = 0;
+ int stripe_count = 0;
+ int i;
+ int rc;
+ ENTRY;
+
+ /* for specific OSTs layout */
+ LASSERT(lum != NULL && lum->lmm_magic == LOV_USER_MAGIC_SPECIFIC);
+ lustre_print_user_md(D_OTHER, lum, __func__);
+
+ rc = lod_qos_ost_in_use_clear(env, lo->ldo_stripenr);
+ if (rc < 0)
+ RETURN(rc);
+
+ v3 = (struct lov_user_md_v3 *)lum;
+ for (i = 0; i < lo->ldo_stripenr; i++) {
+ if (v3->lmm_objects[i].l_ost_idx == lo->ldo_def_stripe_offset) {
+ array_idx = i;
+ break;
+ }
+ }
+ if (i == lo->ldo_stripenr) {
+ CDEBUG(D_OTHER,
+ "%s: start index %d not in the specified list of OSTs\n",
+ lod2obd(m)->obd_name, lo->ldo_def_stripe_offset);
+ RETURN(-EINVAL);
+ }
+
+ for (i = 0; i < lo->ldo_stripenr;
+ i++, array_idx = (array_idx + 1) % lo->ldo_stripenr) {
+ __u32 ost_idx = v3->lmm_objects[array_idx].l_ost_idx;
+
+ if (!cfs_bitmap_check(m->lod_ost_bitmap, ost_idx)) {
+ rc = -ENODEV;
+ break;
+ }
+
+ /*
+ * do not put >1 objects on a single OST
+ */
+ if (lod_qos_is_ost_used(env, ost_idx, stripe_count)) {
+ rc = -EINVAL;
+ break;
+ }
+
+ rc = lod_statfs_and_check(env, m, ost_idx, sfs);
+ if (rc < 0) /* this OSP doesn't feel well */
+ break;
+
+ o = lod_qos_declare_object_on(env, m, ost_idx, th);
+ if (IS_ERR(o)) {
+ rc = PTR_ERR(o);
+ CDEBUG(D_OTHER,
+ "%s: can't declare new object on #%u: %d\n",
+ lod2obd(m)->obd_name, ost_idx, rc);
+ break;
+ }
+
+ /*
+ * We've successfuly declared (reserved) an object
+ */
+ lod_qos_ost_in_use(env, stripe_count, ost_idx);
+ stripe[stripe_count] = o;
+ stripe_count++;
+ }
+
+ RETURN(rc);
+}
+
+/**
+ * Allocate a striping on a predefined set of OSTs.
+ *
+ * Allocates new striping starting from OST provided lo->ldo_def_stripe_offset.
+ * Full OSTs are not considered. The exact order of OSTs is not important and
+ * varies depending on OST status. The allocation procedure prefers the targets
+ * with precreated objects ready. The number of stripes needed and stripe
+ * offset are taken from the object. If that number can not be met, then the
+ * function returns a failure and then it's the caller's responsibility to
+ * release the stripes allocated. All the internal structures are protected,
+ * but no concurrent allocation is allowed on the same objects.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[out] stripe striping created
+ * \param[in] flags not used
+ * \param[in] th transaction handle
+ *
+ * \retval 0 on success
+ * \retval -E2BIG if no enough OSTs are found
+ * \retval -EINVAL requested offset is invalid
+ * \retval negative negated errno on error
+ */
static int lod_alloc_specific(const struct lu_env *env, struct lod_object *lo,
struct dt_object **stripe, int flags,
struct thandle *th)
RETURN(rc);
}
+/**
+ * Check whether QoS allocation should be used.
+ *
+ * A simple helper to decide when QoS allocation should be used:
+ * if it's just a single available target or the used space is
+ * evenly distributed among the targets at the moment, then QoS
+ * allocation algorithm should not be used.
+ *
+ * \param[in] lod LOD device
+ *
+ * \retval 0 should not be used
+ * \retval 1 should be used
+ */
static inline int lod_qos_is_usable(struct lod_device *lod)
{
#ifdef FORCE_QOS
return 1;
}
-/* Alloc objects on OSTs with optimization based on:
- - free space
- - network resources (shared OSS's)
+/**
+ * Allocate a striping using an algorithm with weights.
+ *
+ * The function allocates OST objects to create a striping. The algorithm
+ * used is based on weights (currently only using the free space), and it's
+ * trying to ensure the space is used evenly by OSTs and OSSs. The striping
+ * configuration (# of stripes, offset,
+ * pool) is taken from the object and is prepared by the caller.
+ * If LOV_USES_DEFAULT_STRIPE is not passed and prepared configuration can't
+ * be met due to too few OSTs, then allocation fails. If the flag is
+ * passed and less than 75% of the requested number of stripes can be
+ * allocated, then allocation fails.
+ * No concurrent allocation is allowed on the object and this must be
+ * ensured by the caller. All the internal structures are protected by the
+ * function.
+ * The algorithm has two steps: find available OSTs and calucate their weights,
+ * then select the OSTs the weights used as the probability. An OST with a
+ * higher weight is proportionately more likely to be selected than one with
+ * a lower weight.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[out] stripe striping created
+ * \param[in] flags 0 or LOV_USES_DEFAULT_STRIPE
+ * \param[in] th transaction handle
+ *
+ * \retval 0 on success
+ * \retval -E2BIG if no enough OSTs are found
+ * \retval -EINVAL requested offset is invalid
+ * \retval negative negated errno on error
*/
static int lod_alloc_qos(const struct lu_env *env, struct lod_object *lo,
struct dt_object **stripe, int flags,
RETURN(rc);
}
-/* Find the max stripecount we should use */
+/**
+ * Find largest stripe count the caller can use.
+ *
+ * Find the maximal possible stripe count not greater than \a stripe_count.
+ * Sometimes suggested stripecount can't be reached for a number of reasons:
+ * lack of enough active OSTs or the backend does not support EAs that large.
+ * If the passed one is 0, then the filesystem's default one is used.
+ *
+ * \param[in] lod LOD device
+ * \param[in] magic the format if striping
+ * \param[in] stripe_count count the caller would like to use
+ *
+ * \retval the maximum usable stripe count
+ */
static __u16 lod_get_stripecnt(struct lod_device *lod, __u32 magic,
__u16 stripe_count)
{
return (stripe_count < max_stripes) ? stripe_count : max_stripes;
}
+/**
+ * Create in-core respresentation for a fully-defined striping
+ *
+ * When the caller passes a fully-defined striping (i.e. everything including
+ * OST object FIDs are defined), then we still need to instantiate LU-cache
+ * with the objects representing the stripes defined. This function completes
+ * that task.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] mo LOD object
+ * \param[in] buf buffer containing the striping
+ *
+ * \retval 0 on success
+ * \retval negative negated errno on error
+ */
static int lod_use_defined_striping(const struct lu_env *env,
struct lod_object *mo,
const struct lu_buf *buf)
RETURN(rc);
}
+/**
+ * Parse suggested striping configuration.
+ *
+ * The caller gets a suggested striping configuration from a number of sources
+ * including per-directory default and applications. Then it needs to verify
+ * the suggested striping is valid, apply missing bits and store the resulting
+ * configuration in the object to be used by the allocator later. Must not be
+ * called concurrently against the same object. It's OK to provide a
+ * fully-defined striping.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[in] buf buffer containing the striping
+ *
+ * \retval 0 on success
+ * \retval negative negated errno on error
+ */
static int lod_qos_parse_config(const struct lu_env *env,
struct lod_object *lo,
const struct lu_buf *buf)
struct lod_device *d = lu2lod_dev(lod2lu_obj(lo)->lo_dev);
struct lov_user_md_v1 *v1 = NULL;
struct lov_user_md_v3 *v3 = NULL;
- struct pool_desc *pool;
+ char *pool_name = NULL;
__u32 magic;
int rc;
+ unsigned int size;
ENTRY;
if (buf == NULL || buf->lb_buf == NULL || buf->lb_len == 0)
RETURN(0);
+ v3 = buf->lb_buf;
v1 = buf->lb_buf;
magic = v1->lmm_magic;
- if (magic == __swab32(LOV_USER_MAGIC_V1)) {
+ if (unlikely(magic == LOV_MAGIC_V1_DEF || magic == LOV_MAGIC_V3_DEF)) {
+ /* try to use as fully defined striping */
+ rc = lod_use_defined_striping(env, lo, buf);
+ RETURN(rc);
+ }
+
+ switch (magic) {
+ case __swab32(LOV_USER_MAGIC_V1):
lustre_swab_lov_user_md_v1(v1);
magic = v1->lmm_magic;
- } else if (magic == __swab32(LOV_USER_MAGIC_V3)) {
- v3 = buf->lb_buf;
+ /* fall through */
+ case LOV_USER_MAGIC_V1:
+ size = sizeof(*v1);
+ break;
+
+ case __swab32(LOV_USER_MAGIC_V3):
lustre_swab_lov_user_md_v3(v3);
magic = v3->lmm_magic;
- }
+ /* fall through */
+ case LOV_USER_MAGIC_V3:
+ size = sizeof(*v3);
+ pool_name = v3->lmm_pool_name;
+ break;
- if (unlikely(magic != LOV_MAGIC_V1 && magic != LOV_MAGIC_V3)) {
- /* try to use as fully defined striping */
- rc = lod_use_defined_striping(env, lo, buf);
- RETURN(rc);
+ case __swab32(LOV_USER_MAGIC_SPECIFIC):
+ lustre_swab_lov_user_md_v3(v3);
+ lustre_swab_lov_user_md_objects(v3->lmm_objects,
+ v3->lmm_stripe_count);
+ magic = v3->lmm_magic;
+ /* fall through */
+ case LOV_USER_MAGIC_SPECIFIC:
+ if (v3->lmm_stripe_offset == LOV_OFFSET_DEFAULT)
+ v3->lmm_stripe_offset = v3->lmm_objects[0].l_ost_idx;
+ if (v3->lmm_pool_name[0] != '\0')
+ pool_name = v3->lmm_pool_name;
+ size = lov_user_md_size(v3->lmm_stripe_count,
+ LOV_USER_MAGIC_SPECIFIC);
+ break;
+
+ default:
+ CERROR("%s: unrecognized magic %X\n",
+ lod2obd(d)->obd_name, magic);
+ RETURN(-EINVAL);
}
- if (unlikely(buf->lb_len < sizeof(*v1))) {
- CERROR("wrong size: %u\n", (unsigned) buf->lb_len);
+ if (unlikely(buf->lb_len < size)) {
+ CERROR("%s: wrong size: %zd, expect: %u\n",
+ lod2obd(d)->obd_name, buf->lb_len, size);
RETURN(-EINVAL);
}
+ lustre_print_user_md(D_OTHER, v1, "parse config");
+
v1->lmm_magic = magic;
if (v1->lmm_pattern == 0)
v1->lmm_pattern = LOV_PATTERN_RAID0;
if (lov_pattern(v1->lmm_pattern) != LOV_PATTERN_RAID0) {
- CERROR("invalid pattern: %x\n", v1->lmm_pattern);
+ CERROR("%s: invalid pattern: %x\n",
+ lod2obd(d)->obd_name, v1->lmm_pattern);
RETURN(-EINVAL);
}
lo->ldo_pattern = v1->lmm_pattern;
- if (v1->lmm_stripe_size)
+ if (v1->lmm_stripe_size > 0)
lo->ldo_stripe_size = v1->lmm_stripe_size;
+
if (lo->ldo_stripe_size & (LOV_MIN_STRIPE_SIZE - 1))
lo->ldo_stripe_size = LOV_MIN_STRIPE_SIZE;
- if (v1->lmm_stripe_count)
+ if (v1->lmm_stripe_count > 0)
lo->ldo_stripenr = v1->lmm_stripe_count;
- if ((v1->lmm_stripe_offset >= d->lod_desc.ld_tgt_count) &&
- (v1->lmm_stripe_offset != (typeof(v1->lmm_stripe_offset))(-1))) {
- CERROR("invalid offset: %x\n", v1->lmm_stripe_offset);
- RETURN(-EINVAL);
- }
lo->ldo_def_stripe_offset = v1->lmm_stripe_offset;
- CDEBUG(D_OTHER, "lsm: %u size, %u stripes, %u offset\n",
- v1->lmm_stripe_size, v1->lmm_stripe_count,
- v1->lmm_stripe_offset);
-
- if (v1->lmm_magic == LOV_MAGIC_V3) {
- if (buf->lb_len < sizeof(*v3)) {
- CERROR("wrong size: %u\n", (unsigned) buf->lb_len);
- RETURN(-EINVAL);
- }
-
- v3 = buf->lb_buf;
- lod_object_set_pool(lo, v3->lmm_pool_name);
+ lod_object_set_pool(lo, NULL);
+ if (pool_name != NULL) {
+ struct pool_desc *pool;
/* In the function below, .hs_keycmp resolves to
* pool_hashkey_keycmp() */
/* coverity[overrun-buffer-val] */
- pool = lod_find_pool(d, v3->lmm_pool_name);
+ pool = lod_find_pool(d, pool_name);
if (pool != NULL) {
- if (lo->ldo_def_stripe_offset !=
- (typeof(v1->lmm_stripe_offset))(-1)) {
- rc = lo->ldo_def_stripe_offset;
- rc = lod_check_index_in_pool(rc, pool);
+ if (lo->ldo_def_stripe_offset != LOV_OFFSET_DEFAULT) {
+ rc = lod_check_index_in_pool(
+ lo->ldo_def_stripe_offset, pool);
if (rc < 0) {
lod_pool_putref(pool);
- CERROR("invalid offset\n");
+ CERROR("%s: invalid offset, %u\n",
+ lod2obd(d)->obd_name,
+ lo->ldo_def_stripe_offset);
RETURN(-EINVAL);
}
}
if (lo->ldo_stripenr > pool_tgt_count(pool))
- lo->ldo_stripenr= pool_tgt_count(pool);
+ lo->ldo_stripenr = pool_tgt_count(pool);
lod_pool_putref(pool);
}
- } else
- lod_object_set_pool(lo, NULL);
+
+ lod_object_set_pool(lo, pool_name);
+ }
/* fixup for released file */
if (lo->ldo_pattern & LOV_PATTERN_F_RELEASED) {
RETURN(0);
}
-/*
- * buf should be NULL or contain striping settings
+/**
+ * Create a striping for an obejct.
+ *
+ * The function creates a new striping for the object. A buffer containing
+ * configuration hints can be provided optionally. The function tries QoS
+ * algorithm first unless free space is distributed evenly among OSTs, but
+ * by default RR algorithm is preferred due to internal concurrency (QoS is
+ * serialized). The caller must ensure no concurrent calls to the function
+ * are made against the same object.
+ *
+ * \param[in] env execution environment for this thread
+ * \param[in] lo LOD object
+ * \param[in] attr attributes OST objects will be declared with
+ * \param[in] buf suggested striping configuration or NULL
+ * \param[in] th transaction handle
+ *
+ * \retval 0 on success
+ * \retval negative negated errno on error
*/
int lod_qos_prep_create(const struct lu_env *env, struct lod_object *lo,
struct lu_attr *attr, const struct lu_buf *buf,
GOTO(out, rc = 0);
if (likely(lo->ldo_stripe == NULL)) {
+ struct lov_user_md *lum = NULL;
+
/*
* no striping has been created so far
*/
*/
lod_qos_statfs_update(env, d);
lo->ldo_stripenr = lod_get_stripecnt(d, LOV_MAGIC,
- lo->ldo_stripenr);
+ lo->ldo_stripenr);
stripe_len = lo->ldo_stripenr;
OBD_ALLOC(stripe, sizeof(stripe[0]) * stripe_len);
/* XXX: support for non-0 files w/o objects */
CDEBUG(D_OTHER, "tgt_count %d stripenr %d\n",
d->lod_desc.ld_tgt_count, stripe_len);
- if (lo->ldo_def_stripe_offset >= d->lod_desc.ld_tgt_count) {
+
+ if (buf != NULL && buf->lb_buf != NULL)
+ lum = buf->lb_buf;
+
+ if (lum != NULL && lum->lmm_magic == LOV_USER_MAGIC_SPECIFIC) {
+ rc = lod_alloc_ost_list(env, lo, stripe, lum, th);
+ } else if (lo->ldo_def_stripe_offset == LOV_OFFSET_DEFAULT) {
rc = lod_alloc_qos(env, lo, stripe, flag, th);
if (rc == -EAGAIN)
rc = lod_alloc_rr(env, lo, stripe, flag, th);
o = lo->ldo_stripe[i];
LASSERT(o);
- rc = dt_declare_create(env, o, attr, NULL, NULL, th);
- if (rc) {
+ rc = lod_sub_object_declare_create(env, o, attr, NULL,
+ NULL, th);
+ if (rc < 0) {
CERROR("can't declare create: %d\n", rc);
break;
}