From 87dc8a01281a4543ed25c367dace6e0f267e0dd1 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 13 Jun 2018 16:26:23 +0200 Subject: [PATCH] s390/cio: ensure that a chpid is registered only once Improve locking in chp_new to make sure that we don't register the same chpid twice. Chpid registration was synchronized via the machine check handler thread but we also have codepaths to look for new chpids triggered independent of that thread (during IPL or resume from hibernate). Signed-off-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/chp.c | 21 +++++++++++---------- drivers/s390/cio/css.c | 3 +-- 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c index afbdee7..51038ec 100644 --- a/drivers/s390/cio/chp.c +++ b/drivers/s390/cio/chp.c @@ -471,14 +471,17 @@ int chp_new(struct chp_id chpid) { struct channel_subsystem *css = css_by_id(chpid.cssid); struct channel_path *chp; - int ret; + int ret = 0; + mutex_lock(&css->mutex); if (chp_is_registered(chpid)) - return 0; - chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); - if (!chp) - return -ENOMEM; + goto out; + chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); + if (!chp) { + ret = -ENOMEM; + goto out; + } /* fill in status, etc. */ chp->chpid = chpid; chp->state = 1; @@ -505,21 +508,20 @@ int chp_new(struct chp_id chpid) put_device(&chp->dev); goto out; } - mutex_lock(&css->mutex); + if (css->cm_enabled) { ret = chp_add_cmg_attr(chp); if (ret) { device_unregister(&chp->dev); - mutex_unlock(&css->mutex); goto out; } } css->chps[chpid.id] = chp; - mutex_unlock(&css->mutex); goto out; out_free: kfree(chp); out: + mutex_unlock(&css->mutex); return ret; } @@ -585,8 +587,7 @@ static void chp_process_crw(struct crw *crw0, struct crw *crw1, switch (crw0->erc) { case CRW_ERC_IPARM: /* Path has come. */ case CRW_ERC_INIT: - if (!chp_is_registered(chpid)) - chp_new(chpid); + chp_new(chpid); chsc_chp_online(chpid); break; case CRW_ERC_PERRI: /* Path has gone. */ diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 9263a0f..830a83e 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -244,8 +244,7 @@ static void ssd_register_chpids(struct chsc_ssd_info *ssd) for (i = 0; i < 8; i++) { mask = 0x80 >> i; if (ssd->path_mask & mask) - if (!chp_is_registered(ssd->chpid[i])) - chp_new(ssd->chpid[i]); + chp_new(ssd->chpid[i]); } } -- 2.7.4