diff options
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c index d8a5cb3cd2bd..ce1507023132 100644 --- a/drivers/scsi/cxlflash/superpipe.c +++ b/drivers/scsi/cxlflash/superpipe.c @@ -1615,6 +1615,13 @@ err1: * place at the same time and the failure was due to CXL services being * unable to keep up. * + * As this routine is called on ioctl context, it holds the ioctl r/w + * semaphore that is used to drain ioctls in recovery scenarios. The + * implementation to achieve the pacing described above (a local mutex) + * requires that the ioctl r/w semaphore be dropped and reacquired to + * avoid a 3-way deadlock when multiple process recoveries operate in + * parallel. + * * Because a user can detect an error condition before the kernel, it is * quite possible for this routine to act as the kernel's EEH detection * source (MMIO read of mbox_r). Because of this, there is a window of @@ -1642,9 +1649,17 @@ static int cxlflash_afu_recover(struct scsi_device *sdev, int rc = 0; atomic_inc(&cfg->recovery_threads); + up_read(&cfg->ioctl_rwsem); rc = mutex_lock_interruptible(mutex); + down_read(&cfg->ioctl_rwsem); if (rc) goto out; + rc = check_state(cfg); + if (rc) { + dev_err(dev, "%s: Failed state! rc=%d\n", __func__, rc); + rc = -ENODEV; + goto out; + } dev_dbg(dev, "%s: reason 0x%016llX rctxid=%016llX\n", __func__, recover->reason, rctxid); |