On 08/28/2017 10:41 PM, Bart Van Assche wrote:
> Introduce struct scsi_vpd for the VPD page length, data and the
> RCU head that will be used to free the VPD data. Use kfree_rcu()
> instead of kfree() to free VPD data. Move the VPD buffer pointer
> check inside the RCU read lock in the sysfs code. Only annotate
> pointers that are shared across threads with __rcu. Use
> rcu_dereference() when dereferencing an RCU pointer. This patch
> suppresses about twenty sparse complaints about the vpd_pg8[03]
> pointers. This patch also fixes a race condition, namely that
> updating of the VPD pointers and length variables in struct
> scsi_device was not atomic with reference to the code reading
> these variables. See also "Does the update code tolerate concurrent
> accesses?" in Documentation/RCU/checklist.txt.
>
> Fixes: commit 09e2b0b14690 ("scsi: rescan VPD attributes")
> Signed-off-by: Bart Van Assche <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: Hannes Reinecke <[email protected]>
> Cc: Johannes Thumshirn <[email protected]>
> Cc: Shane Seymour <[email protected]>
> ---
> drivers/scsi/scsi.c | 44 ++++++++++++++++++--------------------------
> drivers/scsi/scsi_lib.c | 16 ++++++++--------
> drivers/scsi/scsi_sysfs.c | 29 ++++++++++++++++++++---------
> include/scsi/scsi_device.h | 18 ++++++++++++++----
> 4 files changed, 60 insertions(+), 47 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
[email protected] +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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