[PATCH v5 3/7] scsi: core: Fail host creation if creating the proc directory fails

Bart Van Assche
2022-09-14T22:57:00Z

Users expect that the contents of /proc/scsi is in sync with the contents
of /sys/class/scsi_host. Hence fail host creation if creating the proc
directory fails.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/hosts.c | 3 ++-
drivers/scsi/scsi_priv.h | 4 ++--
drivers/scsi/scsi_proc.c | 13 +++++++++----
3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 9857dba09c95..12346e2297fd 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -519,7 +519,8 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
"failed to create tmf workq\n");
goto fail;
}
- scsi_proc_hostdir_add(shost->hostt);
+ if (scsi_proc_hostdir_add(shost->hostt) < 0)
+ goto fail;
return shost;
fail:
/*
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index f385b3f04d6e..8c2e32121db1 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -100,14 +100,14 @@ extern void scsi_evt_thread(struct work_struct *work);

/* scsi_proc.c */
#ifdef CONFIG_SCSI_PROC_FS
-extern void scsi_proc_hostdir_add(struct scsi_host_template *);
+extern int scsi_proc_hostdir_add(struct scsi_host_template *);
extern void scsi_proc_hostdir_rm(struct scsi_host_template *);
extern void scsi_proc_host_add(struct Scsi_Host *);
extern void scsi_proc_host_rm(struct Scsi_Host *);
extern int scsi_init_procfs(void);
extern void scsi_exit_procfs(void);
#else
-# define scsi_proc_hostdir_add(sht) do { } while (0)
+# define scsi_proc_hostdir_add(sht) 0
# define scsi_proc_hostdir_rm(sht) do { } while (0)
# define scsi_proc_host_add(shost) do { } while (0)
# define scsi_proc_host_rm(shost) do { } while (0)
diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c
index 456b43097288..8c84f1a74773 100644
--- a/drivers/scsi/scsi_proc.c
+++ b/drivers/scsi/scsi_proc.c
@@ -108,20 +108,25 @@ static const struct proc_ops proc_scsi_ops = {
*
* Sets sht->proc_dir to the new directory.
*/
-
-void scsi_proc_hostdir_add(struct scsi_host_template *sht)
+int scsi_proc_hostdir_add(struct scsi_host_template *sht)
{
+ int ret = 0;
+
if (!sht->show_info)
- return;
+ return 0;

mutex_lock(&global_host_template_mutex);
if (!sht->present++) {
sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
- if (!sht->proc_dir)
+ if (!sht->proc_dir) {
printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
__func__, sht->proc_name);
+ ret = -ENOMEM;
+ }
}
mutex_unlock(&global_host_template_mutex);
+
+ return ret;
}

/**