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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_scan.c | |
| parent | 43f7571be077ee4673466cbcba115427d68440e1 (diff) | |
| download | linux-exynos-0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff.tar.gz linux-exynos-0db6ca8a5e1ea585795db3643ec7d50fc8cb1aff.tar.bz2 linux-exynos-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_scan.c')
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 6f7128f49c30..e6de4eee97a3 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -231,6 +231,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, sdev->id = starget->id; sdev->lun = lun; sdev->channel = starget->channel; + mutex_init(&sdev->state_mutex); sdev->sdev_state = SDEV_CREATED; INIT_LIST_HEAD(&sdev->siblings); INIT_LIST_HEAD(&sdev->same_target_siblings); @@ -943,16 +944,17 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, /* set the device running here so that slave configure * may do I/O */ + mutex_lock(&sdev->state_mutex); ret = scsi_device_set_state(sdev, SDEV_RUNNING); - if (ret) { + if (ret) ret = scsi_device_set_state(sdev, SDEV_BLOCK); + mutex_unlock(&sdev->state_mutex); - if (ret) { - sdev_printk(KERN_ERR, sdev, - "in wrong state %s to complete scan\n", - scsi_device_state_name(sdev->sdev_state)); - return SCSI_SCAN_NO_RESPONSE; - } + if (ret) { + sdev_printk(KERN_ERR, sdev, + "in wrong state %s to complete scan\n", + scsi_device_state_name(sdev->sdev_state)); + return SCSI_SCAN_NO_RESPONSE; } if (*bflags & BLIST_MS_192_BYTES_FOR_3F) |