From: Emoly Liu <emoly....@intel.com> Since the inflight request holds import refcount as well as export, sometimes obd_disconnect() in client_common_put_super() can't put the last refcount of OSC import (e.g. due to network disconnection), this will cause cl_cache being accessed after free.
To fix this issue, ccc_users is used as cl_cache refcount, and lov/llite/osc all hold one cl_cache refcount respectively, to avoid the race that a new OST is being added into the system when the client is mounted. The following cl_cache functions are added: - cl_cache_init(): allocate and initialize cl_cache - cl_cache_incref(): increase cl_cache refcount - cl_cache_decref(): decrease cl_cache refcount and free the cache if refcount=0. Signed-off-by: Emoly Liu <emoly....@intel.com> Reviewed-on: http://review.whamcloud.com/13746 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6173 Reviewed-by: Niu Yawei <yawei....@intel.com> Signed-off-by: Oleg Drokin <gr...@linuxhacker.ru> --- drivers/staging/lustre/lustre/include/cl_object.h | 10 ++++- drivers/staging/lustre/lustre/include/obd.h | 2 +- .../staging/lustre/lustre/llite/llite_internal.h | 2 +- drivers/staging/lustre/lustre/llite/llite_lib.c | 35 +++++++--------- drivers/staging/lustre/lustre/llite/lproc_llite.c | 6 +-- drivers/staging/lustre/lustre/lov/lov_obd.c | 7 ++++ drivers/staging/lustre/lustre/obdclass/cl_page.c | 46 ++++++++++++++++++++++ drivers/staging/lustre/lustre/osc/osc_page.c | 4 +- drivers/staging/lustre/lustre/osc/osc_request.c | 4 +- 9 files changed, 86 insertions(+), 30 deletions(-) diff --git a/drivers/staging/lustre/lustre/include/cl_object.h b/drivers/staging/lustre/lustre/include/cl_object.h index 36ca935..3cd4a25 100644 --- a/drivers/staging/lustre/lustre/include/cl_object.h +++ b/drivers/staging/lustre/lustre/include/cl_object.h @@ -2322,7 +2322,8 @@ void cl_lock_descr_print(const struct lu_env *env, void *cookie, */ struct cl_client_cache { /** - * # of users (OSCs) + * # of client cache refcount + * # of users (OSCs) + 2 (held by llite and lov) */ atomic_t ccc_users; /** @@ -2357,6 +2358,13 @@ struct cl_client_cache { }; +/** + * cl_cache functions + */ +struct cl_client_cache *cl_cache_init(unsigned long lru_page_max); +void cl_cache_incref(struct cl_client_cache *cache); +void cl_cache_decref(struct cl_client_cache *cache); + /** @} cl_page */ /** \defgroup cl_lock cl_lock diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h index e654d42..ed1081a 100644 --- a/drivers/staging/lustre/lustre/include/obd.h +++ b/drivers/staging/lustre/lustre/include/obd.h @@ -415,7 +415,7 @@ struct lov_obd { enum lustre_sec_part lov_sp_me; /* Cached LRU and unstable data from upper layer */ - void *lov_cache; + struct cl_client_cache *lov_cache; struct rw_semaphore lov_notify_lock; diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h index 7c1a3254..74cd241 100644 --- a/drivers/staging/lustre/lustre/llite/llite_internal.h +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h @@ -493,7 +493,7 @@ struct ll_sb_info { * any page which is sent to a server as part of a bulk request, * but is uncommitted to stable storage. */ - struct cl_client_cache ll_cache; + struct cl_client_cache *ll_cache; struct lprocfs_stats *ll_ra_stats; diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c index ac833db..83f4e1a 100644 --- a/drivers/staging/lustre/lustre/llite/llite_lib.c +++ b/drivers/staging/lustre/lustre/llite/llite_lib.c @@ -83,15 +83,11 @@ static struct ll_sb_info *ll_init_sbi(struct super_block *sb) pages = si.totalram - si.totalhigh; lru_page_max = pages / 2; - /* initialize ll_cache data */ - atomic_set(&sbi->ll_cache.ccc_users, 0); - sbi->ll_cache.ccc_lru_max = lru_page_max; - atomic_set(&sbi->ll_cache.ccc_lru_left, lru_page_max); - spin_lock_init(&sbi->ll_cache.ccc_lru_lock); - INIT_LIST_HEAD(&sbi->ll_cache.ccc_lru); - - atomic_set(&sbi->ll_cache.ccc_unstable_nr, 0); - init_waitqueue_head(&sbi->ll_cache.ccc_unstable_waitq); + sbi->ll_cache = cl_cache_init(lru_page_max); + if (!sbi->ll_cache) { + kfree(sbi); + return NULL; + } sbi->ll_ra_info.ra_max_pages_per_file = min(pages / 32, SBI_DEFAULT_READAHEAD_MAX); @@ -131,6 +127,11 @@ static void ll_free_sbi(struct super_block *sb) { struct ll_sb_info *sbi = ll_s2sbi(sb); + if (sbi->ll_cache) { + cl_cache_decref(sbi->ll_cache); + sbi->ll_cache = NULL; + } + kfree(sbi); } @@ -514,8 +515,8 @@ static int client_common_fill_super(struct super_block *sb, char *md, char *dt, cl_sb_init(sb); err = obd_set_info_async(NULL, sbi->ll_dt_exp, sizeof(KEY_CACHE_SET), - KEY_CACHE_SET, sizeof(sbi->ll_cache), - &sbi->ll_cache, NULL); + KEY_CACHE_SET, sizeof(*sbi->ll_cache), + sbi->ll_cache, NULL); sb->s_root = d_make_root(root); if (!sb->s_root) { @@ -560,8 +561,6 @@ out_lock_cn_cb: out_dt: obd_disconnect(sbi->ll_dt_exp); sbi->ll_dt_exp = NULL; - /* Make sure all OScs are gone, since cl_cache is accessing sbi. */ - obd_zombie_barrier(); out_md_fid: obd_fid_fini(sbi->ll_md_exp->exp_obd); out_md: @@ -618,10 +617,6 @@ static void client_common_put_super(struct super_block *sb) obd_fid_fini(sbi->ll_dt_exp->exp_obd); obd_disconnect(sbi->ll_dt_exp); sbi->ll_dt_exp = NULL; - /* wait till all OSCs are gone, since cl_cache is accessing sbi. - * see LU-2543. - */ - obd_zombie_barrier(); ldebugfs_unregister_mountpoint(sbi); @@ -962,12 +957,12 @@ void ll_put_super(struct super_block *sb) if (!force) { struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL); - rc = l_wait_event(sbi->ll_cache.ccc_unstable_waitq, - !atomic_read(&sbi->ll_cache.ccc_unstable_nr), + rc = l_wait_event(sbi->ll_cache->ccc_unstable_waitq, + !atomic_read(&sbi->ll_cache->ccc_unstable_nr), &lwi); } - ccc_count = atomic_read(&sbi->ll_cache.ccc_unstable_nr); + ccc_count = atomic_read(&sbi->ll_cache->ccc_unstable_nr); if (!force && rc != -EINTR) LASSERTF(!ccc_count, "count: %i\n", ccc_count); diff --git a/drivers/staging/lustre/lustre/llite/lproc_llite.c b/drivers/staging/lustre/lustre/llite/lproc_llite.c index 6e9a8a5..1f00bce 100644 --- a/drivers/staging/lustre/lustre/llite/lproc_llite.c +++ b/drivers/staging/lustre/lustre/llite/lproc_llite.c @@ -360,7 +360,7 @@ static int ll_max_cached_mb_seq_show(struct seq_file *m, void *v) { struct super_block *sb = m->private; struct ll_sb_info *sbi = ll_s2sbi(sb); - struct cl_client_cache *cache = &sbi->ll_cache; + struct cl_client_cache *cache = sbi->ll_cache; int shift = 20 - PAGE_SHIFT; int max_cached_mb; int unused_mb; @@ -387,7 +387,7 @@ static ssize_t ll_max_cached_mb_seq_write(struct file *file, { struct super_block *sb = ((struct seq_file *)file->private_data)->private; struct ll_sb_info *sbi = ll_s2sbi(sb); - struct cl_client_cache *cache = &sbi->ll_cache; + struct cl_client_cache *cache = sbi->ll_cache; struct lu_env *env; int refcheck; int mult, rc, pages_number; @@ -826,7 +826,7 @@ static ssize_t unstable_stats_show(struct kobject *kobj, { struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info, ll_kobj); - struct cl_client_cache *cache = &sbi->ll_cache; + struct cl_client_cache *cache = sbi->ll_cache; int pages, mb; pages = atomic_read(&cache->ccc_unstable_nr); diff --git a/drivers/staging/lustre/lustre/lov/lov_obd.c b/drivers/staging/lustre/lustre/lov/lov_obd.c index c87096e..9b92d55 100644 --- a/drivers/staging/lustre/lustre/lov/lov_obd.c +++ b/drivers/staging/lustre/lustre/lov/lov_obd.c @@ -892,6 +892,12 @@ static int lov_cleanup(struct obd_device *obd) kfree(lov->lov_tgts); lov->lov_tgt_size = 0; } + + if (lov->lov_cache) { + cl_cache_decref(lov->lov_cache); + lov->lov_cache = NULL; + } + return 0; } @@ -2121,6 +2127,7 @@ static int lov_set_info_async(const struct lu_env *env, struct obd_export *exp, LASSERT(!lov->lov_cache); lov->lov_cache = val; do_inactive = 1; + cl_cache_incref(lov->lov_cache); } for (i = 0; i < count; i++, val = (char *)val + incr) { diff --git a/drivers/staging/lustre/lustre/obdclass/cl_page.c b/drivers/staging/lustre/lustre/obdclass/cl_page.c index 71bff49..db2dc6b 100644 --- a/drivers/staging/lustre/lustre/obdclass/cl_page.c +++ b/drivers/staging/lustre/lustre/obdclass/cl_page.c @@ -1072,3 +1072,49 @@ void cl_page_slice_add(struct cl_page *page, struct cl_page_slice *slice, slice->cpl_page = page; } EXPORT_SYMBOL(cl_page_slice_add); + +/** + * Allocate and initialize cl_cache, called by ll_init_sbi(). + */ +struct cl_client_cache *cl_cache_init(unsigned long lru_page_max) +{ + struct cl_client_cache *cache = NULL; + + cache = kzalloc(sizeof(*cache), GFP_KERNEL); + if (!cache) + return NULL; + + /* Initialize cache data */ + atomic_set(&cache->ccc_users, 1); + cache->ccc_lru_max = lru_page_max; + atomic_set(&cache->ccc_lru_left, lru_page_max); + spin_lock_init(&cache->ccc_lru_lock); + INIT_LIST_HEAD(&cache->ccc_lru); + + atomic_set(&cache->ccc_unstable_nr, 0); + init_waitqueue_head(&cache->ccc_unstable_waitq); + + return cache; +} +EXPORT_SYMBOL(cl_cache_init); + +/** + * Increase cl_cache refcount + */ +void cl_cache_incref(struct cl_client_cache *cache) +{ + atomic_inc(&cache->ccc_users); +} +EXPORT_SYMBOL(cl_cache_incref); + +/** + * Decrease cl_cache refcount and free the cache if refcount=0. + * Since llite, lov and osc all hold cl_cache refcount, + * the free will not cause race. (LU-6173) + */ +void cl_cache_decref(struct cl_client_cache *cache) +{ + if (atomic_dec_and_test(&cache->ccc_users)) + kfree(cache); +} +EXPORT_SYMBOL(cl_cache_decref); diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c index 57d8a5a..c1aa11e 100644 --- a/drivers/staging/lustre/lustre/osc/osc_page.c +++ b/drivers/staging/lustre/lustre/osc/osc_page.c @@ -414,7 +414,7 @@ static int osc_cache_too_much(struct client_obd *cli) int pages = atomic_read(&cli->cl_lru_in_list); unsigned long budget; - budget = cache->ccc_lru_max / atomic_read(&cache->ccc_users); + budget = cache->ccc_lru_max / (atomic_read(&cache->ccc_users) - 2); /* if it's going to run out LRU slots, we should free some, but not * too much to maintain fairness among OSCs. @@ -714,7 +714,7 @@ int osc_lru_reclaim(struct client_obd *cli) cache->ccc_lru_shrinkers++; list_move_tail(&cli->cl_lru_osc, &cache->ccc_lru); - max_scans = atomic_read(&cache->ccc_users); + max_scans = atomic_read(&cache->ccc_users) - 2; while (--max_scans > 0 && !list_empty(&cache->ccc_lru)) { cli = list_entry(cache->ccc_lru.next, struct client_obd, cl_lru_osc); diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c index 7260027..9334349 100644 --- a/drivers/staging/lustre/lustre/osc/osc_request.c +++ b/drivers/staging/lustre/lustre/osc/osc_request.c @@ -2913,7 +2913,7 @@ static int osc_set_info_async(const struct lu_env *env, struct obd_export *exp, LASSERT(!cli->cl_cache); /* only once */ cli->cl_cache = val; - atomic_inc(&cli->cl_cache->ccc_users); + cl_cache_incref(cli->cl_cache); cli->cl_lru_left = &cli->cl_cache->ccc_lru_left; /* add this osc into entity list */ @@ -3293,7 +3293,7 @@ static int osc_cleanup(struct obd_device *obd) list_del_init(&cli->cl_lru_osc); spin_unlock(&cli->cl_cache->ccc_lru_lock); cli->cl_lru_left = NULL; - atomic_dec(&cli->cl_cache->ccc_users); + cl_cache_decref(cli->cl_cache); cli->cl_cache = NULL; } -- 2.7.4 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
