s390/dasd: cleanup profiling

The dasd driver has a lot of duplicated code to handle
dasd_global_profile. With this patch we use the same code for the
global and the per device profiling data. Note that dasd_stats_write
had to change slightly to maintain some odd differences between
A) per device and global profile and B) proc and sysfs interface
usage.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 27 insertions, 85 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index a67e8dae73c3..be34ef41b7c7 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -674,10 +674,7 @@ EXPORT_SYMBOL(dasd_enable_device);
 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 
 #ifdef CONFIG_DASD_PROFILE
-static struct dasd_profile_info dasd_global_profile_data;
 struct dasd_profile dasd_global_profile = {
-        .dentry = NULL,
-        .data = &dasd_global_profile_data,
         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 };
 static struct dentry *dasd_debugfs_global_entry;
@@ -701,7 +698,7 @@ static void dasd_profile_start(struct dasd_block *block,
                                 break;
 
         spin_lock(&dasd_global_profile.lock);
-        if (dasd_global_profile_level) {
+        if (dasd_global_profile.data) {
                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
                 if (rq_data_dir(req) == READ)
                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
@@ -832,7 +829,7 @@ static void dasd_profile_end(struct dasd_block *block,
         dasd_profile_counter(endtime, endtime_ind);
 
         spin_lock(&dasd_global_profile.lock);
-        if (dasd_global_profile_level) {
+        if (dasd_global_profile.data) {
                 dasd_profile_end_add_data(dasd_global_profile.data,
                                           cqr->startdev != block->base,
                                           cqr->cpmode == 1,
@@ -884,11 +881,6 @@ void dasd_profile_reset(struct dasd_profile *profile)
         spin_unlock_bh(&profile->lock);
 }
 
-void dasd_global_profile_reset(void)
-{
-        dasd_profile_reset(&dasd_global_profile);
-}
-
 int dasd_profile_on(struct dasd_profile *profile)
 {
         struct dasd_profile_info *data;
@@ -956,12 +948,20 @@ static ssize_t dasd_stats_write(struct file *file,
                 dasd_profile_reset(prof);
         } else if (strncmp(str, "on", 2) == 0) {
                 rc = dasd_profile_on(prof);
-                if (!rc)
-                        rc = user_len;
+                if (rc)
+                        goto out;
+                rc = user_len;
+                if (prof == &dasd_global_profile) {
+                        dasd_profile_reset(prof);
+                        dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
+                }
         } else if (strncmp(str, "off", 3) == 0) {
+                if (prof == &dasd_global_profile)
+                        dasd_global_profile_level = DASD_PROFILE_OFF;
                 dasd_profile_off(prof);
         } else
                 rc = -EINVAL;
+out:
         vfree(buffer);
         return rc;
 }
@@ -1051,59 +1051,6 @@ static const struct file_operations dasd_stats_raw_fops = {
         .write          = dasd_stats_write,
 };
 
-static ssize_t dasd_stats_global_write(struct file *file,
-                                       const char __user *user_buf,
-                                       size_t user_len, loff_t *pos)
-{
-        char *buffer, *str;
-        ssize_t rc;
-
-        if (user_len > 65536)
-                user_len = 65536;
-        buffer = dasd_get_user_string(user_buf, user_len);
-        if (IS_ERR(buffer))
-                return PTR_ERR(buffer);
-        str = skip_spaces(buffer);
-        rc = user_len;
-        if (strncmp(str, "reset", 5) == 0) {
-                dasd_global_profile_reset();
-        } else if (strncmp(str, "on", 2) == 0) {
-                dasd_global_profile_reset();
-                dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
-        } else if (strncmp(str, "off", 3) == 0) {
-                dasd_global_profile_level = DASD_PROFILE_OFF;
-        } else
-                rc = -EINVAL;
-        vfree(buffer);
-        return rc;
-}
-
-static int dasd_stats_global_show(struct seq_file *m, void *v)
-{
-        if (!dasd_global_profile_level) {
-                seq_puts(m, "disabled\n");
-                return 0;
-        }
-        spin_lock_bh(&dasd_global_profile.lock);
-        dasd_stats_seq_print(m, dasd_global_profile.data);
-        spin_unlock_bh(&dasd_global_profile.lock);
-        return 0;
-}
-
-static int dasd_stats_global_open(struct inode *inode, struct file *file)
-{
-        return single_open(file, dasd_stats_global_show, NULL);
-}
-
-static const struct file_operations dasd_stats_global_fops = {
-        .owner          = THIS_MODULE,
-        .open           = dasd_stats_global_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = single_release,
-        .write          = dasd_stats_global_write,
-};
-
 static void dasd_profile_init(struct dasd_profile *profile,
                               struct dentry *base_dentry)
 {
@@ -1132,19 +1079,16 @@ static void dasd_profile_exit(struct dasd_profile *profile)
 static void dasd_statistics_removeroot(void)
 {
         dasd_global_profile_level = DASD_PROFILE_OFF;
-        debugfs_remove(dasd_global_profile.dentry);
-        dasd_global_profile.dentry = NULL;
+        dasd_profile_exit(&dasd_global_profile);
         debugfs_remove(dasd_debugfs_global_entry);
         debugfs_remove(dasd_debugfs_root_entry);
 }
 
 static void dasd_statistics_createroot(void)
 {
-        umode_t mode;
         struct dentry *pde;
 
         dasd_debugfs_root_entry = NULL;
-        dasd_debugfs_global_entry = NULL;
         pde = debugfs_create_dir("dasd", NULL);
         if (!pde || IS_ERR(pde))
                 goto error;
@@ -1153,13 +1097,7 @@ static void dasd_statistics_createroot(void)
         if (!pde || IS_ERR(pde))
                 goto error;
         dasd_debugfs_global_entry = pde;
-
-        mode = (S_IRUSR | S_IWUSR | S_IFREG);
-        pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
-                                  NULL, &dasd_stats_global_fops);
-        if (!pde || IS_ERR(pde))
-                goto error;
-        dasd_global_profile.dentry = pde;
+        dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
         return;
 
 error:
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 91731fa05604..227e3dea3155 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -728,7 +728,6 @@ int dasd_device_is_ro(struct dasd_device *);
 void dasd_profile_reset(struct dasd_profile *);
 int dasd_profile_on(struct dasd_profile *);
 void dasd_profile_off(struct dasd_profile *);
-void dasd_global_profile_reset(void);
 char *dasd_get_user_string(const char __user *, size_t);
 
 /* externals in dasd_devmap.c */
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 76410084c48f..aa7bb2d1da81 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -212,15 +212,15 @@ static int dasd_stats_proc_show(struct seq_file *m, void *v)
         struct dasd_profile_info *prof;
         int factor;
 
-        /* check for active profiling */
-        if (!dasd_global_profile_level) {
+        spin_lock_bh(&dasd_global_profile.lock);
+        prof = dasd_global_profile.data;
+        if (!prof) {
+                spin_unlock_bh(&dasd_global_profile.lock);
                 seq_printf(m, "Statistics are off - they might be "
                                     "switched on using 'echo set on > "
                                     "/proc/dasd/statistics'\n");
                 return 0;
         }
-        spin_lock_bh(&dasd_global_profile.lock);
-        prof = dasd_global_profile.data;
 
         /* prevent counter 'overflow' on output */
         for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
@@ -293,14 +293,19 @@ static ssize_t dasd_stats_proc_write(struct file *file,
                                 dasd_stats_all_block_off();
                                 goto out_error;
                         }
-                        dasd_global_profile_reset();
+                        rc = dasd_profile_on(&dasd_global_profile);
+                        if (rc) {
+                                dasd_stats_all_block_off();
+                                goto out_error;
+                        }
+                        dasd_profile_reset(&dasd_global_profile);
                         dasd_global_profile_level = DASD_PROFILE_ON;
                         pr_info("The statistics feature has been switched "
                                 "on\n");
                 } else if (strcmp(str, "off") == 0) {
-                        /* switch off and reset statistics profiling */
+                        /* switch off statistics profiling */
                         dasd_global_profile_level = DASD_PROFILE_OFF;
-                        dasd_global_profile_reset();
+                        dasd_profile_off(&dasd_global_profile);
                         dasd_stats_all_block_off();
                         pr_info("The statistics feature has been switched "
                                 "off\n");
@@ -308,7 +313,7 @@ static ssize_t dasd_stats_proc_write(struct file *file,
                         goto out_parse_error;
         } else if (strncmp(str, "reset", 5) == 0) {
                 /* reset the statistics */
-                dasd_global_profile_reset();
+                dasd_profile_reset(&dasd_global_profile);
                 dasd_stats_all_block_reset();
                 pr_info("The statistics have been reset\n");
         } else