diff options
Diffstat (limited to 'drivers/scsi/cxlflash/superpipe.c')
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c index 34acb587d730..18a5e11aac3a 100644 --- a/drivers/scsi/cxlflash/superpipe.c +++ b/drivers/scsi/cxlflash/superpipe.c @@ -283,6 +283,24 @@ out: * @sdev: SCSI device associated with LUN. * @lli: LUN destined for capacity request. * + * The READ_CAP16 can take quite a while to complete. Should an EEH occur while + * in scsi_execute(), the EEH handler will attempt to recover. As part of the + * recovery, the handler drains all currently running ioctls, waiting until they + * have completed before proceeding with a reset. As this routine is used on the + * ioctl path, this can create a condition where the EEH handler becomes stuck, + * infinitely waiting for this ioctl thread. To avoid this behavior, temporarily + * unmark this thread as an ioctl thread by releasing the ioctl read semaphore. + * This will allow the EEH handler to proceed with a recovery while this thread + * is still running. Once the scsi_execute() returns, reacquire the ioctl read + * semaphore and check the adapter state in case it changed while inside of + * scsi_execute(). The state check will wait if the adapter is still being + * recovered or return a failure if the recovery failed. In the event that the + * adapter reset failed, simply return the failure as the ioctl would be unable + * to continue. + * + * Note that the above puts a requirement on this routine to only be called on + * an ioctl thread. + * * Return: 0 on success, -errno on failure */ static int read_cap16(struct scsi_device *sdev, struct llun_info *lli) @@ -314,8 +332,18 @@ retry: dev_dbg(dev, "%s: %ssending cmd(0x%x)\n", __func__, retry_cnt ? "re" : "", scsi_cmd[0]); + /* Drop the ioctl read semahpore across lengthy call */ + up_read(&cfg->ioctl_rwsem); result = scsi_execute(sdev, scsi_cmd, DMA_FROM_DEVICE, cmd_buf, CMD_BUFSIZE, sense_buf, to, CMD_RETRIES, 0, NULL); + down_read(&cfg->ioctl_rwsem); + rc = check_state(cfg); + if (rc) { + dev_err(dev, "%s: Failed state! result=0x08%X\n", + __func__, result); + rc = -ENODEV; + goto out; + } if (driver_byte(result) == DRIVER_SENSE) { result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */ @@ -1221,7 +1249,7 @@ static const struct file_operations null_fops = { * * Return: 0 on success, -errno on failure */ -static int check_state(struct cxlflash_cfg *cfg) +int check_state(struct cxlflash_cfg *cfg) { struct device *dev = &cfg->dev->dev; int rc = 0; |