Commit 0aaa3fad authored by John Garry's avatar John Garry Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: Change shost list lock to a mutex 



The shost list lock, sdebug_host_list_lock, is a spinlock. We would only
lock in non-atomic context in this driver, so use a mutex instead, which is
friendlier if we need to schedule when iterating.

Signed-off-by: default avatarJohn Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-4-john.g.garry@oracle.com


Acked-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 00f9d622

drivers/scsi/scsi_debug.c

+19 −19
Original line number Diff line number Diff line
@@ -816,7 +816,7 @@ static int sdebug_cylinders_per; /* cylinders per surface */ 
static int sdebug_sectors_per;		/* sectors per cylinder */



static LIST_HEAD(sdebug_host_list);

static DEFINE_SPINLOCK(sdebug_host_list_lock);

static DEFINE_MUTEX(sdebug_host_list_mutex);



static struct xarray per_store_arr;

static struct xarray *per_store_ap = &per_store_arr;
@@ -908,7 +908,7 @@ static void sdebug_max_tgts_luns(void) 
	struct sdebug_host_info *sdbg_host;

	struct Scsi_Host *hpnt;



	spin_lock(&sdebug_host_list_lock);

	mutex_lock(&sdebug_host_list_mutex);

	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {

		hpnt = sdbg_host->shost;

		if ((hpnt->this_id >= 0) &&
@@ -919,7 +919,7 @@ static void sdebug_max_tgts_luns(void) 
		/* sdebug_max_luns; */

		hpnt->max_lun = SCSI_W_LUN_REPORT_LUNS + 1;

	}

	spin_unlock(&sdebug_host_list_lock);

	mutex_unlock(&sdebug_host_list_mutex);

}



enum sdeb_cmd_data {SDEB_IN_DATA = 0, SDEB_IN_CDB = 1};
@@ -1051,14 +1051,14 @@ static void all_config_cdb_len(void) 
	struct Scsi_Host *shost;

	struct scsi_device *sdev;



	spin_lock(&sdebug_host_list_lock);

	mutex_lock(&sdebug_host_list_mutex);

	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {

		shost = sdbg_host->shost;

		shost_for_each_device(sdev, shost) {

			config_cdb_len(sdev);

		}

	}

	spin_unlock(&sdebug_host_list_lock);

	mutex_unlock(&sdebug_host_list_mutex);

}



static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)
@@ -5423,7 +5423,7 @@ static int scsi_debug_host_reset(struct scsi_cmnd *SCpnt) 
	++num_host_resets;

	if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)

		sdev_printk(KERN_INFO, SCpnt->device, "%s\n", __func__);

	spin_lock(&sdebug_host_list_lock);

	mutex_lock(&sdebug_host_list_mutex);

	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {

		list_for_each_entry(devip, &sdbg_host->dev_info_list,

				    dev_list) {
@@ -5431,7 +5431,7 @@ static int scsi_debug_host_reset(struct scsi_cmnd *SCpnt) 
			++k;

		}

	}

	spin_unlock(&sdebug_host_list_lock);

	mutex_unlock(&sdebug_host_list_mutex);

	stop_all_queued();

	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)

		sdev_printk(KERN_INFO, SCpnt->device,
@@ -6337,13 +6337,13 @@ static ssize_t lun_format_store(struct device_driver *ddp, const char *buf, 
			struct sdebug_host_info *sdhp;

			struct sdebug_dev_info *dp;



			spin_lock(&sdebug_host_list_lock);

			mutex_lock(&sdebug_host_list_mutex);

			list_for_each_entry(sdhp, &sdebug_host_list, host_list) {

				list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) {

					set_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm);

				}

			}

			spin_unlock(&sdebug_host_list_lock);

			mutex_unlock(&sdebug_host_list_mutex);

		}

		return count;

	}
@@ -6373,7 +6373,7 @@ static ssize_t max_luns_store(struct device_driver *ddp, const char *buf, 
			struct sdebug_host_info *sdhp;

			struct sdebug_dev_info *dp;



			spin_lock(&sdebug_host_list_lock);

			mutex_lock(&sdebug_host_list_mutex);

			list_for_each_entry(sdhp, &sdebug_host_list,

					    host_list) {

				list_for_each_entry(dp, &sdhp->dev_info_list,
@@ -6382,7 +6382,7 @@ static ssize_t max_luns_store(struct device_driver *ddp, const char *buf, 
						dp->uas_bm);

				}

			}

			spin_unlock(&sdebug_host_list_lock);

			mutex_unlock(&sdebug_host_list_mutex);

		}

		return count;

	}
@@ -6489,7 +6489,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf, 
			struct sdebug_host_info *sdhp;

			struct sdebug_dev_info *dp;



			spin_lock(&sdebug_host_list_lock);

			mutex_lock(&sdebug_host_list_mutex);

			list_for_each_entry(sdhp, &sdebug_host_list,

					    host_list) {

				list_for_each_entry(dp, &sdhp->dev_info_list,
@@ -6498,7 +6498,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf, 
						dp->uas_bm);

				}

			}

			spin_unlock(&sdebug_host_list_lock);

			mutex_unlock(&sdebug_host_list_mutex);

		}

		return count;

	}
@@ -7258,9 +7258,9 @@ static int sdebug_add_host_helper(int per_host_idx) 
			goto clean;

	}



	spin_lock(&sdebug_host_list_lock);

	mutex_lock(&sdebug_host_list_mutex);

	list_add_tail(&sdbg_host->host_list, &sdebug_host_list);

	spin_unlock(&sdebug_host_list_lock);

	mutex_unlock(&sdebug_host_list_mutex);



	sdbg_host->dev.bus = &pseudo_lld_bus;

	sdbg_host->dev.parent = pseudo_primary;
@@ -7269,9 +7269,9 @@ static int sdebug_add_host_helper(int per_host_idx) 


	error = device_register(&sdbg_host->dev);

	if (error) {

		spin_lock(&sdebug_host_list_lock);

		mutex_lock(&sdebug_host_list_mutex);

		list_del(&sdbg_host->host_list);

		spin_unlock(&sdebug_host_list_lock);

		mutex_unlock(&sdebug_host_list_mutex);

		goto clean;

	}
@@ -7311,7 +7311,7 @@ static void sdebug_do_remove_host(bool the_end) 
	struct sdebug_host_info *sdbg_host = NULL;

	struct sdebug_host_info *sdbg_host2;



	spin_lock(&sdebug_host_list_lock);

	mutex_lock(&sdebug_host_list_mutex);

	if (!list_empty(&sdebug_host_list)) {

		sdbg_host = list_entry(sdebug_host_list.prev,

				       struct sdebug_host_info, host_list);
@@ -7336,7 +7336,7 @@ static void sdebug_do_remove_host(bool the_end) 
	}

	if (sdbg_host)

		list_del(&sdbg_host->host_list);

	spin_unlock(&sdebug_host_list_lock);

	mutex_unlock(&sdebug_host_list_mutex);



	if (!sdbg_host)

		return;