diff options
Diffstat (limited to 'drivers/scsi/scsi_proc.c')
| -rw-r--r-- | drivers/scsi/scsi_proc.c | 137 |
1 files changed, 116 insertions, 21 deletions
diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c index 95aee1ad1383..4a6eb1741be0 100644 --- a/drivers/scsi/scsi_proc.c +++ b/drivers/scsi/scsi_proc.c @@ -43,8 +43,23 @@ static struct proc_dir_entry *proc_scsi; -/* Protect sht->present and sht->proc_dir */ +/* Protects scsi_proc_list */ static DEFINE_MUTEX(global_host_template_mutex); +static LIST_HEAD(scsi_proc_list); + +/** + * struct scsi_proc_entry - (host template, SCSI proc dir) association + * @entry: entry in scsi_proc_list. + * @sht: SCSI host template associated with the procfs directory. + * @proc_dir: procfs directory associated with the SCSI host template. + * @present: Number of SCSI hosts instantiated for @sht. + */ +struct scsi_proc_entry { + struct list_head entry; + const struct scsi_host_template *sht; + struct proc_dir_entry *proc_dir; + unsigned int present; +}; static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) @@ -83,6 +98,45 @@ static int proc_scsi_host_open(struct inode *inode, struct file *file) 4 * PAGE_SIZE); } +static struct scsi_proc_entry * +__scsi_lookup_proc_entry(const struct scsi_host_template *sht) +{ + struct scsi_proc_entry *e; + + lockdep_assert_held(&global_host_template_mutex); + + list_for_each_entry(e, &scsi_proc_list, entry) + if (e->sht == sht) + return e; + + return NULL; +} + +static struct scsi_proc_entry * +scsi_lookup_proc_entry(const struct scsi_host_template *sht) +{ + struct scsi_proc_entry *e; + + mutex_lock(&global_host_template_mutex); + e = __scsi_lookup_proc_entry(sht); + mutex_unlock(&global_host_template_mutex); + + return e; +} + +/** + * scsi_template_proc_dir() - returns the procfs dir for a SCSI host template + * @sht: SCSI host template pointer. + */ +struct proc_dir_entry * +scsi_template_proc_dir(const struct scsi_host_template *sht) +{ + struct scsi_proc_entry *e = scsi_lookup_proc_entry(sht); + + return e ? e->proc_dir : NULL; +} +EXPORT_SYMBOL_GPL(scsi_template_proc_dir); + static const struct proc_ops proc_scsi_ops = { .proc_open = proc_scsi_host_open, .proc_release = single_release, @@ -97,35 +151,61 @@ 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(const struct scsi_host_template *sht) { + struct scsi_proc_entry *e; + int ret; + 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) - printk(KERN_ERR "%s: proc_mkdir failed for %s\n", - __func__, sht->proc_name); + e = __scsi_lookup_proc_entry(sht); + if (!e) { + e = kzalloc(sizeof(*e), GFP_KERNEL); + if (!e) { + ret = -ENOMEM; + goto unlock; + } } + if (e->present++) + goto success; + e->proc_dir = proc_mkdir(sht->proc_name, proc_scsi); + if (!e->proc_dir) { + printk(KERN_ERR "%s: proc_mkdir failed for %s\n", __func__, + sht->proc_name); + ret = -ENOMEM; + goto unlock; + } + e->sht = sht; + list_add_tail(&e->entry, &scsi_proc_list); +success: + e = NULL; + ret = 0; +unlock: mutex_unlock(&global_host_template_mutex); + + kfree(e); + return ret; } /** * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host * @sht: owner of directory */ -void scsi_proc_hostdir_rm(struct scsi_host_template *sht) +void scsi_proc_hostdir_rm(const struct scsi_host_template *sht) { + struct scsi_proc_entry *e; + if (!sht->show_info) return; mutex_lock(&global_host_template_mutex); - if (!--sht->present && sht->proc_dir) { + e = __scsi_lookup_proc_entry(sht); + if (e && !--e->present) { remove_proc_entry(sht->proc_name, proc_scsi); - sht->proc_dir = NULL; + list_del(&e->entry); + kfree(e); } mutex_unlock(&global_host_template_mutex); } @@ -137,20 +217,29 @@ void scsi_proc_hostdir_rm(struct scsi_host_template *sht) */ void scsi_proc_host_add(struct Scsi_Host *shost) { - struct scsi_host_template *sht = shost->hostt; + const struct scsi_host_template *sht = shost->hostt; + struct scsi_proc_entry *e; struct proc_dir_entry *p; char name[10]; - if (!sht->proc_dir) + if (!sht->show_info) return; + e = scsi_lookup_proc_entry(sht); + if (!e) + goto err; + sprintf(name,"%d", shost->host_no); - p = proc_create_data(name, S_IRUGO | S_IWUSR, - sht->proc_dir, &proc_scsi_ops, shost); + p = proc_create_data(name, S_IRUGO | S_IWUSR, e->proc_dir, + &proc_scsi_ops, shost); if (!p) - printk(KERN_ERR "%s: Failed to register host %d in" - "%s\n", __func__, shost->host_no, - sht->proc_name); + goto err; + return; + +err: + shost_printk(KERN_ERR, shost, + "%s: Failed to register host (%s failed)\n", __func__, + e ? "proc_create_data()" : "scsi_proc_hostdir_add()"); } /** @@ -159,13 +248,19 @@ void scsi_proc_host_add(struct Scsi_Host *shost) */ void scsi_proc_host_rm(struct Scsi_Host *shost) { + const struct scsi_host_template *sht = shost->hostt; + struct scsi_proc_entry *e; char name[10]; - if (!shost->hostt->proc_dir) + if (!sht->show_info) + return; + + e = scsi_lookup_proc_entry(sht); + if (!e) return; sprintf(name,"%d", shost->host_no); - remove_proc_entry(name, shost->hostt->proc_dir); + remove_proc_entry(name, e->proc_dir); } /** * proc_print_scsidevice - return data about this host |