From f56b355ca8ae0a2312da094630790b923b00d8b4 Mon Sep 17 00:00:00 2001 From: Jinshan Xiong Date: Wed, 30 Mar 2016 19:48:31 -0400 Subject: [PATCH] staging/lustre/osc: add weight function for DLM lock Use weigh_ast to decide if a lock covers any pages. In recovery, weigh_ast will be used to decide if a DLM read lock covers any locked pages, or it will be canceled instead being recovered. The problem with the original implementation is that it attached each osc_page to an osc_lock also changed lock state to add every pages for readahead. Signed-off-by: Jinshan Xiong Reviewed-on: http://review.whamcloud.com/7894 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3321 Reviewed-by: Bobi Jam Reviewed-by: Lai Siyao Signed-off-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman --- .../staging/lustre/lustre/ldlm/ldlm_request.c | 9 +- .../lustre/lustre/osc/osc_cl_internal.h | 20 ---- .../staging/lustre/lustre/osc/osc_internal.h | 3 +- drivers/staging/lustre/lustre/osc/osc_lock.c | 113 +++++++++++++----- drivers/staging/lustre/lustre/osc/osc_page.c | 78 +----------- .../staging/lustre/lustre/osc/osc_request.c | 5 +- 6 files changed, 89 insertions(+), 139 deletions(-) diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c index c7904a96f9af..d5968e01edd8 100644 --- a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c @@ -1139,10 +1139,10 @@ static ldlm_policy_res_t ldlm_cancel_no_wait_policy(struct ldlm_namespace *ns, ldlm_policy_res_t result = LDLM_POLICY_CANCEL_LOCK; ldlm_cancel_for_recovery cb = ns->ns_cancel_for_recovery; - lock_res_and_lock(lock); - /* don't check added & count since we want to process all locks - * from unused list + * from unused list. + * It's fine to not take lock to access lock->l_resource since + * the lock has already been granted so it won't change. */ switch (lock->l_resource->lr_type) { case LDLM_EXTENT: @@ -1151,11 +1151,12 @@ static ldlm_policy_res_t ldlm_cancel_no_wait_policy(struct ldlm_namespace *ns, break; default: result = LDLM_POLICY_SKIP_LOCK; + lock_res_and_lock(lock); lock->l_flags |= LDLM_FL_SKIPPED; + unlock_res_and_lock(lock); break; } - unlock_res_and_lock(lock); return result; } diff --git a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h index 0e06bedeb0dd..cf87043ce4b8 100644 --- a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h +++ b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h @@ -274,16 +274,6 @@ struct osc_lock { struct ldlm_enqueue_info ols_einfo; enum osc_lock_state ols_state; - /** - * How many pages are using this lock for io, currently only used by - * read-ahead. If non-zero, the underlying dlm lock won't be cancelled - * during recovery to avoid deadlock. see bz16774. - * - * \see osc_page::ops_lock - * \see osc_page_addref_lock(), osc_page_putref_lock() - */ - atomic_t ols_pageref; - /** * true, if ldlm_lock_addref() was called against * osc_lock::ols_lock. This is used for sanity checking. @@ -400,16 +390,6 @@ struct osc_page { * Submit time - the time when the page is starting RPC. For debugging. */ unsigned long ops_submit_time; - - /** - * A lock of which we hold a reference covers this page. Only used by - * read-ahead: for a readahead page, we hold it's covering lock to - * prevent it from being canceled during recovery. - * - * \see osc_lock::ols_pageref - * \see osc_page_addref_lock(), osc_page_putref_lock(). - */ - struct cl_lock *ops_lock; }; extern struct kmem_cache *osc_lock_kmem; diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h index 906225c520d6..b7fb01ad60a6 100644 --- a/drivers/staging/lustre/lustre/osc/osc_internal.h +++ b/drivers/staging/lustre/lustre/osc/osc_internal.h @@ -141,6 +141,7 @@ int osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, int osc_lru_reclaim(struct client_obd *cli); extern spinlock_t osc_ast_guard; +unsigned long osc_ldlm_weigh_ast(struct ldlm_lock *dlmlock); int osc_setup(struct obd_device *obd, struct lustre_cfg *lcfg); @@ -181,8 +182,6 @@ static inline struct osc_device *obd2osc_dev(const struct obd_device *d) return container_of0(d->obd_lu_dev, struct osc_device, od_cl.cd_lu_dev); } -int osc_dlm_lock_pageref(struct ldlm_lock *dlm); - extern struct kmem_cache *osc_quota_kmem; struct osc_quota_info { /** linkage for quota hash table */ diff --git a/drivers/staging/lustre/lustre/osc/osc_lock.c b/drivers/staging/lustre/lustre/osc/osc_lock.c index 3a8a6d129377..978b6ea67107 100644 --- a/drivers/staging/lustre/lustre/osc/osc_lock.c +++ b/drivers/staging/lustre/lustre/osc/osc_lock.c @@ -51,8 +51,6 @@ * @{ */ -#define _PAGEREF_MAGIC (-10000000) - /***************************************************************************** * * Type conversions. @@ -248,8 +246,6 @@ static void osc_lock_fini(const struct lu_env *env, */ osc_lock_unhold(ols); LASSERT(!ols->ols_lock); - LASSERT(atomic_read(&ols->ols_pageref) == 0 || - atomic_read(&ols->ols_pageref) == _PAGEREF_MAGIC); kmem_cache_free(osc_lock_kmem, ols); } @@ -895,11 +891,88 @@ static int osc_ldlm_glimpse_ast(struct ldlm_lock *dlmlock, void *data) return result; } -static unsigned long osc_lock_weigh(const struct lu_env *env, - const struct cl_lock_slice *slice) +static int weigh_cb(const struct lu_env *env, struct cl_io *io, + struct osc_page *ops, void *cbdata) { - /* TODO: check how many pages are covered by this lock */ - return cl2osc(slice->cls_obj)->oo_npages; + struct cl_page *page = ops->ops_cl.cpl_page; + + if (cl_page_is_vmlocked(env, page)) { + (*(unsigned long *)cbdata)++; + return CLP_GANG_ABORT; + } + + return CLP_GANG_OKAY; +} + +static unsigned long osc_lock_weight(const struct lu_env *env, + const struct osc_lock *ols) +{ + struct cl_io *io = &osc_env_info(env)->oti_io; + struct cl_lock_descr *descr = &ols->ols_cl.cls_lock->cll_descr; + struct cl_object *obj = ols->ols_cl.cls_obj; + unsigned long npages = 0; + int result; + + io->ci_obj = cl_object_top(obj); + io->ci_ignore_layout = 1; + result = cl_io_init(env, io, CIT_MISC, io->ci_obj); + if (result != 0) + return result; + + do { + result = osc_page_gang_lookup(env, io, cl2osc(obj), + descr->cld_start, descr->cld_end, + weigh_cb, (void *)&npages); + if (result == CLP_GANG_ABORT) + break; + if (result == CLP_GANG_RESCHED) + cond_resched(); + } while (result != CLP_GANG_OKAY); + cl_io_fini(env, io); + + return npages; +} + +/** + * Get the weight of dlm lock for early cancellation. + */ +unsigned long osc_ldlm_weigh_ast(struct ldlm_lock *dlmlock) +{ + struct cl_env_nest nest; + struct lu_env *env; + struct osc_lock *lock; + unsigned long weight; + + might_sleep(); + /* + * osc_ldlm_weigh_ast has a complex context since it might be called + * because of lock canceling, or from user's input. We have to make + * a new environment for it. Probably it is implementation safe to use + * the upper context because cl_lock_put don't modify environment + * variables. But just in case .. + */ + env = cl_env_nested_get(&nest); + if (IS_ERR(env)) + /* Mostly because lack of memory, do not eliminate this lock */ + return 1; + + LASSERT(dlmlock->l_resource->lr_type == LDLM_EXTENT); + lock = osc_ast_data_get(dlmlock); + if (!lock) { + /* cl_lock was destroyed because of memory pressure. + * It is much reasonable to assign this type of lock + * a lower cost. + */ + weight = 0; + goto out; + } + + weight = osc_lock_weight(env, lock); + osc_ast_data_put(env, lock); + +out: + cl_env_nested_put(&nest, env); + return weight; } static void osc_lock_build_einfo(const struct lu_env *env, @@ -1468,7 +1541,6 @@ static const struct cl_lock_operations osc_lock_ops = { .clo_delete = osc_lock_delete, .clo_state = osc_lock_state, .clo_cancel = osc_lock_cancel, - .clo_weigh = osc_lock_weigh, .clo_print = osc_lock_print, .clo_fits_into = osc_lock_fits_into, }; @@ -1570,7 +1642,6 @@ int osc_lock_init(const struct lu_env *env, __u32 enqflags = lock->cll_descr.cld_enq_flags; osc_lock_build_einfo(env, lock, clk, &clk->ols_einfo); - atomic_set(&clk->ols_pageref, 0); clk->ols_state = OLS_NEW; clk->ols_flags = osc_enq2ldlm_flags(enqflags); @@ -1597,26 +1668,4 @@ int osc_lock_init(const struct lu_env *env, return result; } -int osc_dlm_lock_pageref(struct ldlm_lock *dlm) -{ - struct osc_lock *olock; - int rc = 0; - - spin_lock(&osc_ast_guard); - olock = dlm->l_ast_data; - /* - * there's a very rare race with osc_page_addref_lock(), but that - * doesn't matter because in the worst case we don't cancel a lock - * which we actually can, that's no harm. - */ - if (olock && - atomic_add_return(_PAGEREF_MAGIC, - &olock->ols_pageref) != _PAGEREF_MAGIC) { - atomic_sub(_PAGEREF_MAGIC, &olock->ols_pageref); - rc = 1; - } - spin_unlock(&osc_ast_guard); - return rc; -} - /** @} osc */ diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c index eff3b4b3b2b3..8dc62fa04300 100644 --- a/drivers/staging/lustre/lustre/osc/osc_page.c +++ b/drivers/staging/lustre/lustre/osc/osc_page.c @@ -67,10 +67,6 @@ static int osc_page_protected(const struct lu_env *env, static void osc_page_fini(const struct lu_env *env, struct cl_page_slice *slice) { - struct osc_page *opg = cl2osc_page(slice); - - CDEBUG(D_TRACE, "%p\n", opg); - LASSERT(!opg->ops_lock); } static void osc_page_transfer_get(struct osc_page *opg, const char *label) @@ -139,42 +135,6 @@ void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj, policy->l_extent.end = cl_offset(obj, end + 1) - 1; } -static int osc_page_addref_lock(const struct lu_env *env, - struct osc_page *opg, - struct cl_lock *lock) -{ - struct osc_lock *olock; - int rc; - - LASSERT(!opg->ops_lock); - - olock = osc_lock_at(lock); - if (atomic_inc_return(&olock->ols_pageref) <= 0) { - atomic_dec(&olock->ols_pageref); - rc = -ENODATA; - } else { - cl_lock_get(lock); - opg->ops_lock = lock; - rc = 0; - } - return rc; -} - -static void osc_page_putref_lock(const struct lu_env *env, - struct osc_page *opg) -{ - struct cl_lock *lock = opg->ops_lock; - struct osc_lock *olock; - - LASSERT(lock); - olock = osc_lock_at(lock); - - atomic_dec(&olock->ols_pageref); - opg->ops_lock = NULL; - - cl_lock_put(env, lock); -} - static int osc_page_is_under_lock(const struct lu_env *env, const struct cl_page_slice *slice, struct cl_io *unused) @@ -185,39 +145,12 @@ static int osc_page_is_under_lock(const struct lu_env *env, lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page, NULL, 1, 0); if (lock) { - if (osc_page_addref_lock(env, cl2osc_page(slice), lock) == 0) - result = -EBUSY; cl_lock_put(env, lock); + result = -EBUSY; } return result; } -static void osc_page_disown(const struct lu_env *env, - const struct cl_page_slice *slice, - struct cl_io *io) -{ - struct osc_page *opg = cl2osc_page(slice); - - if (unlikely(opg->ops_lock)) - osc_page_putref_lock(env, opg); -} - -static void osc_page_completion_read(const struct lu_env *env, - const struct cl_page_slice *slice, - int ioret) -{ - struct osc_page *opg = cl2osc_page(slice); - - if (likely(opg->ops_lock)) - osc_page_putref_lock(env, opg); -} - -static void osc_page_completion_write(const struct lu_env *env, - const struct cl_page_slice *slice, - int ioret) -{ -} - static const char *osc_list(struct list_head *head) { return list_empty(head) ? "-" : "+"; @@ -366,15 +299,6 @@ static const struct cl_page_operations osc_page_ops = { .cpo_print = osc_page_print, .cpo_delete = osc_page_delete, .cpo_is_under_lock = osc_page_is_under_lock, - .cpo_disown = osc_page_disown, - .io = { - [CRT_READ] = { - .cpo_completion = osc_page_completion_read - }, - [CRT_WRITE] = { - .cpo_completion = osc_page_completion_write - } - }, .cpo_clip = osc_page_clip, .cpo_cancel = osc_page_cancel, .cpo_flush = osc_page_flush diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c index 1ff497f05b2f..1e378e6c1a70 100644 --- a/drivers/staging/lustre/lustre/osc/osc_request.c +++ b/drivers/staging/lustre/lustre/osc/osc_request.c @@ -3131,8 +3131,6 @@ static int osc_import_event(struct obd_device *obd, */ static int osc_cancel_for_recovery(struct ldlm_lock *lock) { - check_res_locked(lock->l_resource); - /* * Cancel all unused extent lock in granted mode LCK_PR or LCK_CR. * @@ -3141,8 +3139,7 @@ static int osc_cancel_for_recovery(struct ldlm_lock *lock) */ if (lock->l_resource->lr_type == LDLM_EXTENT && (lock->l_granted_mode == LCK_PR || - lock->l_granted_mode == LCK_CR) && - (osc_dlm_lock_pageref(lock) == 0)) + lock->l_granted_mode == LCK_CR) && osc_ldlm_weigh_ast(lock) == 0) return 1; return 0; -- 2.30.2