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| author |   Bart Van Assche <bvanassche@acm.org> | 2019-06-17 08:18:19 -0700 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2019-06-20 15:37:02 -0400 |
| commit | bbe9fb0d04b96dda1fd7bd973e094004978b2166 (patch) | |
| tree | ef796d2beef86a4d838ff4c0e47a2c26af82c852 /drivers/scsi/scsi_lib.c | |
| parent | scsi: Restrict user space SCSI device state changes to "running" and "offline" (diff) | |
| download | linux-dev-bbe9fb0d04b96dda1fd7bd973e094004978b2166.tar.xz linux-dev-bbe9fb0d04b96dda1fd7bd973e094004978b2166.zip | |
scsi: Avoid that .queuecommand() gets called for a blocked SCSI device
Several SCSI transport and LLD drivers surround code that does not
tolerate concurrent calls of .queuecommand() with scsi_target_block() /
scsi_target_unblock(). These last two functions use
blk_mq_quiesce_queue() / blk_mq_unquiesce_queue() for scsi-mq request
queues to prevent concurrent .queuecommand() calls. However, that is
not sufficient to prevent .queuecommand() calls from scsi_send_eh_cmnd().
Hence surround the .queuecommand() call from the SCSI error handler with
code that avoids that .queuecommand() gets called in the blocked state.
Note: converting the .queuecommand() call in scsi_send_eh_cmnd() into
code that calls blk_get_request() + blk_execute_rq() is not an option
since scsi_send_eh_cmnd() must be able to make forward progress even
if all requests have been allocated.
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index b1b1a1aaa353..6c84edc53f05 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2616,10 +2616,6 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); * a legal transition). When the device is in this state, command processing * is paused until the device leaves the SDEV_BLOCK state. See also * scsi_internal_device_unblock(). - * - * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after - * scsi_internal_device_block() has blocked a SCSI device and also - * remove the rport mutex lock and unlock calls from srp_queuecommand(). */ static int scsi_internal_device_block(struct scsi_device *sdev) { |