From a8610297ea8849fe47a9442291b38936e3d403cc Mon Sep 17 00:00:00 2001 From: Fan Yong Date: Tue, 16 Aug 2016 16:18:29 -0400 Subject: [PATCH] staging: lustre: obdclass: bug fixes for lu_device_type handling There was no protection when inc/dec lu_device_type::ldt_device_nr, which may caused the ldt_device_nr to be wrong and trigger assert. This patch redefine lu_device_type::ldt_device_nr as atomic type. There was no protection when add/del lu_device_type::ldt_linkage into/from the global lu_device_types list, which may caused bad address accessing. This patch uses the existing obd_types_lock to protect related operations. We do NOT need lu_types_stop() any longer. Such function scans the global lu_device_types list, and for each type item on it which has zerod lu_device_type::ldt_device_nr, call its stop() method. In fact, the lu_device_type::ldt_device_nr only will be zero when the last lu_device_fini() is called, and at that time, inside the lu_device_fini(), its stop() method will be called. So it is unnecessary to call the stop() again via lu_types_stop(). Signed-off-by: Fan Yong Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4604 Reviewed-on: http://review.whamcloud.com/8694 Reviewed-by: Jian Yu Reviewed-by: Andreas Dilger Reviewed-by: Oleg Drokin Signed-off-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- .../staging/lustre/lustre/include/lu_object.h | 3 +- drivers/staging/lustre/lustre/llite/vvp_dev.c | 6 ---- .../lustre/lustre/obdclass/lu_object.c | 34 +++++++++---------- .../lustre/lustre/obdclass/obd_mount.c | 1 - 4 files changed, 18 insertions(+), 26 deletions(-) diff --git a/drivers/staging/lustre/lustre/include/lu_object.h b/drivers/staging/lustre/lustre/include/lu_object.h index 6e25c1bb6aa3..25c12d8d120a 100644 --- a/drivers/staging/lustre/lustre/include/lu_object.h +++ b/drivers/staging/lustre/lustre/include/lu_object.h @@ -327,7 +327,7 @@ struct lu_device_type { /** * Number of existing device type instances. */ - unsigned ldt_device_nr; + atomic_t ldt_device_nr; /** * Linkage into a global list of all device types. * @@ -673,7 +673,6 @@ void lu_object_add(struct lu_object *before, struct lu_object *o); int lu_device_type_init(struct lu_device_type *ldt); void lu_device_type_fini(struct lu_device_type *ldt); -void lu_types_stop(void); /** @} ctors */ diff --git a/drivers/staging/lustre/lustre/llite/vvp_dev.c b/drivers/staging/lustre/lustre/llite/vvp_dev.c index e623216e962d..771c0bd190a5 100644 --- a/drivers/staging/lustre/lustre/llite/vvp_dev.c +++ b/drivers/staging/lustre/lustre/llite/vvp_dev.c @@ -368,12 +368,6 @@ int cl_sb_fini(struct super_block *sb) CERROR("Cannot cleanup cl-stack due to memory shortage.\n"); result = PTR_ERR(env); } - /* - * If mount failed (sbi->ll_cl == NULL), and this there are no other - * mounts, stop device types manually (this usually happens - * automatically when last device is destroyed). - */ - lu_types_stop(); return result; } diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c index 9b03059f34d6..0c00bf81b896 100644 --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c @@ -726,34 +726,31 @@ int lu_device_type_init(struct lu_device_type *ldt) { int result = 0; + atomic_set(&ldt->ldt_device_nr, 0); INIT_LIST_HEAD(&ldt->ldt_linkage); if (ldt->ldt_ops->ldto_init) result = ldt->ldt_ops->ldto_init(ldt); - if (result == 0) + + if (!result) { + spin_lock(&obd_types_lock); list_add(&ldt->ldt_linkage, &lu_device_types); + spin_unlock(&obd_types_lock); + } + return result; } EXPORT_SYMBOL(lu_device_type_init); void lu_device_type_fini(struct lu_device_type *ldt) { + spin_lock(&obd_types_lock); list_del_init(&ldt->ldt_linkage); + spin_unlock(&obd_types_lock); if (ldt->ldt_ops->ldto_fini) ldt->ldt_ops->ldto_fini(ldt); } EXPORT_SYMBOL(lu_device_type_fini); -void lu_types_stop(void) -{ - struct lu_device_type *ldt; - - list_for_each_entry(ldt, &lu_device_types, ldt_linkage) { - if (ldt->ldt_device_nr == 0 && ldt->ldt_ops->ldto_stop) - ldt->ldt_ops->ldto_stop(ldt); - } -} -EXPORT_SYMBOL(lu_types_stop); - /** * Global list of all sites on this node */ @@ -1082,8 +1079,10 @@ EXPORT_SYMBOL(lu_device_put); */ int lu_device_init(struct lu_device *d, struct lu_device_type *t) { - if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start) + if (atomic_inc_return(&t->ldt_device_nr) == 1 && + t->ldt_ops->ldto_start) t->ldt_ops->ldto_start(t); + memset(d, 0, sizeof(*d)); atomic_set(&d->ld_ref, 0); d->ld_type = t; @@ -1098,9 +1097,8 @@ EXPORT_SYMBOL(lu_device_init); */ void lu_device_fini(struct lu_device *d) { - struct lu_device_type *t; + struct lu_device_type *t = d->ld_type; - t = d->ld_type; if (d->ld_obd) { d->ld_obd->obd_lu_dev = NULL; d->ld_obd = NULL; @@ -1109,8 +1107,10 @@ void lu_device_fini(struct lu_device *d) lu_ref_fini(&d->ld_reference); LASSERTF(atomic_read(&d->ld_ref) == 0, "Refcount is %u\n", atomic_read(&d->ld_ref)); - LASSERT(t->ldt_device_nr > 0); - if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop) + LASSERT(atomic_read(&t->ldt_device_nr) > 0); + + if (atomic_dec_and_test(&t->ldt_device_nr) && + t->ldt_ops->ldto_stop) t->ldt_ops->ldto_stop(t); } EXPORT_SYMBOL(lu_device_fini); diff --git a/drivers/staging/lustre/lustre/obdclass/obd_mount.c b/drivers/staging/lustre/lustre/obdclass/obd_mount.c index 4931e37adede..33d6c423c6fb 100644 --- a/drivers/staging/lustre/lustre/obdclass/obd_mount.c +++ b/drivers/staging/lustre/lustre/obdclass/obd_mount.c @@ -670,7 +670,6 @@ int lustre_common_put_super(struct super_block *sb) } /* Drop a ref to the mounted disk */ lustre_put_lsi(sb); - lu_types_stop(); return rc; } EXPORT_SYMBOL(lustre_common_put_super); -- 2.20.1