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| author | Alexandra Winter <wintera@linux.ibm.com> | 2021-09-21 16:52:17 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-09-22 05:02:24 +0200 |
| commit | d2b59bd4b06d84a4eadb520b0f71c62fe8ec0a62 (patch) | |
| tree | 7e5fe772eed361a7afc9e9f0accc14e1e8a05841 /drivers/s390/cio | |
| parent | s390/qeth: Fix deadlock in remove_discipline (diff) | |
| download | linux-d2b59bd4b06d84a4eadb520b0f71c62fe8ec0a62.tar.xz linux-d2b59bd4b06d84a4eadb520b0f71c62fe8ec0a62.zip | |
s390/qeth: fix deadlock during failing recovery
Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed
taking discipline_mutex inside qeth_do_reset(), fixing potential
deadlocks. An error path was missed though, that still takes
discipline_mutex and thus has the original deadlock potential.
Intermittent deadlocks were seen when a qeth channel path is configured
offline, causing a race between qeth_do_reset and ccwgroup_remove.
Call qeth_set_offline() directly in the qeth_do_reset() error case and
then a new variant of ccwgroup_set_offline(), without taking
discipline_mutex.
Fixes: b41b554c1ee7 ("s390/qeth: fix locking for discipline setup / removal")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/s390/cio')
| -rw-r--r-- | drivers/s390/cio/ccwgroup.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 2ec741106cb6..f0538609dfe4 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -77,12 +77,13 @@ EXPORT_SYMBOL(ccwgroup_set_online); /** * ccwgroup_set_offline() - disable a ccwgroup device * @gdev: target ccwgroup device + * @call_gdrv: Call the registered gdrv set_offline function * * This function attempts to put the ccwgroup device into the offline state. * Returns: * %0 on success and a negative error value on failure. */ -int ccwgroup_set_offline(struct ccwgroup_device *gdev) +int ccwgroup_set_offline(struct ccwgroup_device *gdev, bool call_gdrv) { struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver); int ret = -EINVAL; @@ -91,11 +92,16 @@ int ccwgroup_set_offline(struct ccwgroup_device *gdev) return -EAGAIN; if (gdev->state == CCWGROUP_OFFLINE) goto out; + if (!call_gdrv) { + ret = 0; + goto offline; + } if (gdrv->set_offline) ret = gdrv->set_offline(gdev); if (ret) goto out; +offline: gdev->state = CCWGROUP_OFFLINE; out: atomic_set(&gdev->onoff, 0); @@ -124,7 +130,7 @@ static ssize_t ccwgroup_online_store(struct device *dev, if (value == 1) ret = ccwgroup_set_online(gdev); else if (value == 0) - ret = ccwgroup_set_offline(gdev); + ret = ccwgroup_set_offline(gdev, true); else ret = -EINVAL; out: |