s390/dasd: add locking for global_profile access
Access to DASDs global statistics is done without locking which
can lead to inconsistent data. Add locking to fix this. Also move
the relevant structs in a global dasd_profile struct.
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>
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 4abf1196..a67e8da 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -674,8 +674,12 @@
unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
#ifdef CONFIG_DASD_PROFILE
-struct dasd_profile_info dasd_global_profile_data;
-static struct dentry *dasd_global_profile_dentry;
+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;
/*
@@ -696,11 +700,13 @@
if (++counter >= 31)
break;
+ spin_lock(&dasd_global_profile.lock);
if (dasd_global_profile_level) {
- dasd_global_profile_data.dasd_io_nr_req[counter]++;
+ dasd_global_profile.data->dasd_io_nr_req[counter]++;
if (rq_data_dir(req) == READ)
- dasd_global_profile_data.dasd_read_nr_req[counter]++;
+ dasd_global_profile.data->dasd_read_nr_req[counter]++;
}
+ spin_unlock(&dasd_global_profile.lock);
spin_lock(&block->profile.lock);
if (block->profile.data) {
@@ -825,8 +831,9 @@
dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
dasd_profile_counter(endtime, endtime_ind);
+ spin_lock(&dasd_global_profile.lock);
if (dasd_global_profile_level) {
- dasd_profile_end_add_data(&dasd_global_profile_data,
+ dasd_profile_end_add_data(dasd_global_profile.data,
cqr->startdev != block->base,
cqr->cpmode == 1,
rq_data_dir(req) == READ,
@@ -835,6 +842,7 @@
irqtime_ind, irqtimeps_ind,
endtime_ind);
}
+ spin_unlock(&dasd_global_profile.lock);
spin_lock(&block->profile.lock);
if (block->profile.data)
@@ -878,8 +886,7 @@
void dasd_global_profile_reset(void)
{
- memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
- getnstimeofday(&dasd_global_profile_data.starttod);
+ dasd_profile_reset(&dasd_global_profile);
}
int dasd_profile_on(struct dasd_profile *profile)
@@ -1077,7 +1084,9 @@
seq_puts(m, "disabled\n");
return 0;
}
- dasd_stats_seq_print(m, &dasd_global_profile_data);
+ 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;
}
@@ -1123,8 +1132,8 @@
static void dasd_statistics_removeroot(void)
{
dasd_global_profile_level = DASD_PROFILE_OFF;
- debugfs_remove(dasd_global_profile_dentry);
- dasd_global_profile_dentry = NULL;
+ debugfs_remove(dasd_global_profile.dentry);
+ dasd_global_profile.dentry = NULL;
debugfs_remove(dasd_debugfs_global_entry);
debugfs_remove(dasd_debugfs_root_entry);
}
@@ -1136,7 +1145,6 @@
dasd_debugfs_root_entry = NULL;
dasd_debugfs_global_entry = NULL;
- dasd_global_profile_dentry = NULL;
pde = debugfs_create_dir("dasd", NULL);
if (!pde || IS_ERR(pde))
goto error;
@@ -1151,7 +1159,7 @@
NULL, &dasd_stats_global_fops);
if (!pde || IS_ERR(pde))
goto error;
- dasd_global_profile_dentry = pde;
+ dasd_global_profile.dentry = pde;
return;
error: