scsi: core: Fix the scsi_device_put() might_sleep annotation
authorBart Van Assche <bvanassche@acm.org>
Wed, 25 Jan 2023 19:43:11 +0000 (11:43 -0800)
committerMartin K. Petersen <martin.petersen@oracle.com>
Fri, 27 Jan 2023 03:01:31 +0000 (22:01 -0500)
commit2542fc9578d49b3b376231269d4c7c7d4cffd62a
tree575fe96245973259fdb45b790f8bccc24c17d4d7
parent0bfe63d075789456e9589457b29d6f9c279e3252
scsi: core: Fix the scsi_device_put() might_sleep annotation

Although most calls of scsi_device_put() happen from non-atomic context,
alua_rtpg_queue() calls this function from atomic context if
alua_rtpg_queue() itself is called from atomic context. alua_rtpg_queue()
is always called from contexts where the caller must hold at least one
reference to the scsi device in question. This means that the reference
taken by alua_rtpg_queue() itself can't be the last one, and thus can be
dropped without entering the code path in which scsi_device_put() might
actually sleep. Hence move the might_sleep() annotation from
scsi_device_put() into scsi_device_dev_release().

[1] https://lore.kernel.org/linux-scsi/b49e37d5-edfb-4c56-3eeb-62c7d5855c00@linux.ibm.com/
[2] https://lore.kernel.org/linux-scsi/55c35e64-a7d4-9072-46fd-e8eae6a90e96@linux.ibm.com/

Note: a significant part of the above description was written by Martin
Wilck.

Fixes: f93ed747e2c7 ("scsi: core: Release SCSI devices synchronously")
Cc: Martin Wilck <mwilck@suse.com>
Cc: Steffen Maier <maier@linux.ibm.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sachin Sant <sachinp@linux.ibm.com>
Cc: Benjamin Block <bblock@linux.ibm.com>
Reported-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Link: https://lore.kernel.org/r/20230125194311.249553-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/scsi.c
drivers/scsi/scsi_sysfs.c