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| author | Dan Williams <dan.j.williams@intel.com> | 2019-07-18 04:08:26 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2019-07-19 02:23:27 +0300 |
| commit | 87a30e1f05d73a34e6d1895065541369131aaf1c (patch) | |
| tree | a5582d3cd7723db8b7ad2f4801a5540c36c5266a /drivers/nvdimm/core.c | |
| parent | ca6bf264f6d856f959c4239cda1047b587745c67 (diff) | |
| download | linux-87a30e1f05d73a34e6d1895065541369131aaf1c.tar.xz | |
driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.
A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.
Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:
"Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
using it as much as anything else, so user beware :)
I don't object to it if it makes things easier for you to debug."
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
Diffstat (limited to 'drivers/nvdimm/core.c')
| -rw-r--r-- | drivers/nvdimm/core.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c index 5e1f060547bf..9204f1e9fd14 100644 --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -246,7 +246,7 @@ static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf, * * Enforce that uuids can only be changed while the device is disabled * (driver detached) - * LOCKING: expects device_lock() is held on entry + * LOCKING: expects nd_device_lock() is held on entry */ int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf, size_t len) @@ -347,15 +347,15 @@ static DEVICE_ATTR_RO(provider); static int flush_namespaces(struct device *dev, void *data) { - device_lock(dev); - device_unlock(dev); + nd_device_lock(dev); + nd_device_unlock(dev); return 0; } static int flush_regions_dimms(struct device *dev, void *data) { - device_lock(dev); - device_unlock(dev); + nd_device_lock(dev); + nd_device_unlock(dev); device_for_each_child(dev, NULL, flush_namespaces); return 0; } |