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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-06-02 14:21:55 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-06-12 20:55:59 -0400 |
| commit | 0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff (patch) | |
| tree | 52ae689dcddbc9155a840617c405de2b377de618 /drivers/scsi/scsi_lib.c | |
| parent | 43f7571be077ee4673466cbcba115427d68440e1 (diff) | |
| download | linux-stable-0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff.tar.gz linux-stable-0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff.tar.bz2 linux-stable-0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff.zip | |
scsi: Protect SCSI device state changes with a mutex
Serializing SCSI device state changes avoids that two state changes can
occur concurrently, e.g. the state changes in scsi_target_block() and
__scsi_remove_device(). This serialization is essential to make patch
"Make __scsi_remove_device go straight from BLOCKED to DEL" work
reliably.
Enable this mechanism for all scsi_target_*block() callers but not for
the scsi_internal_device_unblock() calls from the mpt3sas driver because
that driver can call scsi_internal_device_unblock() from atomic context.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.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 | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f0eb55744513..4b0bac3ac6ab 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2882,7 +2882,12 @@ static void scsi_wait_for_queuecommand(struct scsi_device *sdev) int scsi_device_quiesce(struct scsi_device *sdev) { - int err = scsi_device_set_state(sdev, SDEV_QUIESCE); + int err; + + mutex_lock(&sdev->state_mutex); + err = scsi_device_set_state(sdev, SDEV_QUIESCE); + mutex_unlock(&sdev->state_mutex); + if (err) return err; @@ -2910,10 +2915,11 @@ void scsi_device_resume(struct scsi_device *sdev) * so assume the state is being managed elsewhere (for example * device deleted during suspend) */ - if (sdev->sdev_state != SDEV_QUIESCE || - scsi_device_set_state(sdev, SDEV_RUNNING)) - return; - scsi_run_queue(sdev->request_queue); + mutex_lock(&sdev->state_mutex); + if (sdev->sdev_state == SDEV_QUIESCE && + scsi_device_set_state(sdev, SDEV_RUNNING) == 0) + scsi_run_queue(sdev->request_queue); + mutex_unlock(&sdev->state_mutex); } EXPORT_SYMBOL(scsi_device_resume); @@ -3012,6 +3018,7 @@ static int scsi_internal_device_block(struct scsi_device *sdev) struct request_queue *q = sdev->request_queue; int err; + mutex_lock(&sdev->state_mutex); err = scsi_internal_device_block_nowait(sdev); if (err == 0) { if (q->mq_ops) @@ -3019,6 +3026,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev) else scsi_wait_for_queuecommand(sdev); } + mutex_unlock(&sdev->state_mutex); + return err; } @@ -3089,7 +3098,13 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); static int scsi_internal_device_unblock(struct scsi_device *sdev, enum scsi_device_state new_state) { - return scsi_internal_device_unblock_nowait(sdev, new_state); + int ret; + + mutex_lock(&sdev->state_mutex); + ret = scsi_internal_device_unblock_nowait(sdev, new_state); + mutex_unlock(&sdev->state_mutex); + + return ret; } static void |