diff options
Diffstat (limited to 'drivers/scsi/cxlflash/vlun.c')
| -rw-r--r-- | drivers/scsi/cxlflash/vlun.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c index b0eaf557cc2f..a53f583e2d7b 100644 --- a/drivers/scsi/cxlflash/vlun.c +++ b/drivers/scsi/cxlflash/vlun.c @@ -400,6 +400,24 @@ static int init_vlun(struct llun_info *lli) * @lba: Logical block address to start write same. * @nblks: Number of logical blocks to write same. * + * The SCSI WRITE_SAME16 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 write_same16(struct scsi_device *sdev, @@ -433,9 +451,20 @@ static int write_same16(struct scsi_device *sdev, put_unaligned_be32(ws_limit < left ? ws_limit : left, &scsi_cmd[10]); + /* Drop the ioctl read semahpore across lengthy call */ + up_read(&cfg->ioctl_rwsem); result = scsi_execute(sdev, scsi_cmd, DMA_TO_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 (result) { dev_err_ratelimited(dev, "%s: command failed for " "offset %lld result=0x%x\n", |