Commit f084fe52 authored by Wenchao Hao's avatar Wenchao Hao Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: Add debugfs interface to fail target reset 



The interface is found at
/sys/kernel/debug/scsi_debug/target<h:c:t>/fail_reset where <h:c:t>
identifies the target to inject errors on. It's a simple bool type
interface which would make this target's reset fail if set to 'Y'.

Signed-off-by: default avatarWenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-10-haowenchao2@huawei.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 02678116

drivers/scsi/scsi_debug.c

+113 −1
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include <linux/xarray.h>

#include <linux/prefetch.h>

#include <linux/debugfs.h>

#include <linux/async.h>



#include <net/checksum.h>
@@ -357,6 +358,11 @@ struct sdebug_dev_info { 
	struct list_head inject_err_list;

};



struct sdebug_target_info {

	bool reset_fail;

	struct dentry *debugfs_entry;

};



struct sdebug_host_info {

	struct list_head host_list;

	int si_idx;	/* sdeb_store_info (per host) xarray index */
@@ -1082,6 +1088,91 @@ static const struct file_operations sdebug_error_fops = { 
	.release = single_release,

};



static int sdebug_target_reset_fail_show(struct seq_file *m, void *p)

{

	struct scsi_target *starget = (struct scsi_target *)m->private;

	struct sdebug_target_info *targetip =

		(struct sdebug_target_info *)starget->hostdata;



	if (targetip)

		seq_printf(m, "%c\n", targetip->reset_fail ? 'Y' : 'N');



	return 0;

}



static int sdebug_target_reset_fail_open(struct inode *inode, struct file *file)

{

	return single_open(file, sdebug_target_reset_fail_show, inode->i_private);

}



static ssize_t sdebug_target_reset_fail_write(struct file *file,

		const char __user *ubuf, size_t count, loff_t *ppos)

{

	int ret;

	struct scsi_target *starget =

		(struct scsi_target *)file->f_inode->i_private;

	struct sdebug_target_info *targetip =

		(struct sdebug_target_info *)starget->hostdata;



	if (targetip) {

		ret = kstrtobool_from_user(ubuf, count, &targetip->reset_fail);

		return ret < 0 ? ret : count;

	}

	return -ENODEV;

}



static const struct file_operations sdebug_target_reset_fail_fops = {

	.open	= sdebug_target_reset_fail_open,

	.read	= seq_read,

	.write	= sdebug_target_reset_fail_write,

	.release = single_release,

};



static int sdebug_target_alloc(struct scsi_target *starget)

{

	struct sdebug_target_info *targetip;

	struct dentry *dentry;



	targetip = kzalloc(sizeof(struct sdebug_target_info), GFP_KERNEL);

	if (!targetip)

		return -ENOMEM;



	targetip->debugfs_entry = debugfs_create_dir(dev_name(&starget->dev),

				sdebug_debugfs_root);

	if (IS_ERR_OR_NULL(targetip->debugfs_entry))

		pr_info("%s: failed to create debugfs directory for target %s\n",

			__func__, dev_name(&starget->dev));



	debugfs_create_file("fail_reset", 0600, targetip->debugfs_entry, starget,

				&sdebug_target_reset_fail_fops);

	if (IS_ERR_OR_NULL(dentry))

		pr_info("%s: failed to create fail_reset file for target %s\n",

			__func__, dev_name(&starget->dev));



	starget->hostdata = targetip;



	return 0;

}



static void sdebug_tartget_cleanup_async(void *data, async_cookie_t cookie)

{

	struct sdebug_target_info *targetip = data;



	debugfs_remove(targetip->debugfs_entry);

	kfree(targetip);

}



static void sdebug_target_destroy(struct scsi_target *starget)

{

	struct sdebug_target_info *targetip;



	targetip = (struct sdebug_target_info *)starget->hostdata;

	if (targetip) {

		starget->hostdata = NULL;

		async_schedule(sdebug_tartget_cleanup_async, targetip);

	}

}



/* Only do the extra work involved in logical block provisioning if one or

 * more of the lbpu, lbpws or lbpws10 parameters are given and we are doing

 * real reads and writes (i.e. not skipping them for speed).
@@ -5642,11 +5733,25 @@ static int scsi_debug_device_reset(struct scsi_cmnd *SCpnt) 
	return SUCCESS;

}



static int sdebug_fail_target_reset(struct scsi_cmnd *cmnd)

{

	struct scsi_target *starget = scsi_target(cmnd->device);

	struct sdebug_target_info *targetip =

		(struct sdebug_target_info *)starget->hostdata;



	if (targetip)

		return targetip->reset_fail;



	return 0;

}



static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)

{

	struct scsi_device *sdp = SCpnt->device;

	struct sdebug_host_info *sdbg_host = shost_to_sdebug_host(sdp->host);

	struct sdebug_dev_info *devip;

	u8 *cmd = SCpnt->cmnd;

	u8 opcode = cmd[0];

	int k = 0;



	++num_target_resets;
@@ -5664,6 +5769,12 @@ static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt) 
		sdev_printk(KERN_INFO, sdp,

			    "%s: %d device(s) found in target\n", __func__, k);



	if (sdebug_fail_target_reset(SCpnt)) {

		scmd_printk(KERN_INFO, SCpnt, "fail target reset 0x%x\n",

			    opcode);

		return FAILED;

	}



	return SUCCESS;

}
@@ -8119,7 +8230,6 @@ static int sdebug_init_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd) 
	return 0;

}





static struct scsi_host_template sdebug_driver_template = {

	.show_info =		scsi_debug_show_info,

	.write_info =		scsi_debug_write_info,
@@ -8149,6 +8259,8 @@ static struct scsi_host_template sdebug_driver_template = { 
	.track_queue_depth =	1,

	.cmd_size = sizeof(struct sdebug_scsi_cmd),

	.init_cmd_priv = sdebug_init_cmd_priv,

	.target_alloc =		sdebug_target_alloc,

	.target_destroy =	sdebug_target_destroy,

};



static int sdebug_driver_probe(struct device *dev)