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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>
This commit is contained in:
Sebastian Ott 2015-01-28 18:44:17 +01:00 committed by Martin Schwidefsky
parent e6d60b368b
commit 8ea55c95c3
3 changed files with 24 additions and 14 deletions
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32
drivers/s390/block/dasd.c
View File

@ -674,8 +674,12 @@ EXPORT_SYMBOL(dasd_enable_device);
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 @@ static void dasd_profile_start(struct dasd_block *block,
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 @@ static void dasd_profile_end(struct dasd_block *block,
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 @@ static void dasd_profile_end(struct dasd_block *block,
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_profile_reset(struct dasd_profile *profile)
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 @@ static int dasd_stats_global_show(struct seq_file *m, void *v)
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_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;
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 @@ static void dasd_statistics_createroot(void)
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 @@ static void dasd_statistics_createroot(void)
NULL, &dasd_stats_global_fops);
if (!pde || IS_ERR(pde))
goto error;
dasd_global_profile_dentry = pde;
dasd_global_profile.dentry = pde;
return;
error:

2
drivers/s390/block/dasd_int.h
View File

@ -651,7 +651,7 @@ dasd_check_blocksize(int bsize)
#define DASD_PROFILE_GLOBAL_ONLY 2
extern debug_info_t *dasd_debug_area;
extern struct dasd_profile_info dasd_global_profile_data;
extern struct dasd_profile dasd_global_profile;
extern unsigned int dasd_global_profile_level;
extern const struct block_device_operations dasd_device_operations;

4
drivers/s390/block/dasd_proc.c
View File

@ -219,7 +219,8 @@ static int dasd_stats_proc_show(struct seq_file *m, void *v)
"/proc/dasd/statistics'\n");
return 0;
}
prof = &dasd_global_profile_data;
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;
@ -255,6 +256,7 @@ static int dasd_stats_proc_show(struct seq_file *m, void *v)
dasd_statistics_array(m, prof->dasd_io_time3, factor);
seq_printf(m, "# of req in chanq at enqueuing (1..32) \n");
dasd_statistics_array(m, prof->dasd_io_nr_req, factor);
spin_unlock_bh(&dasd_global_profile.lock);
#else
seq_printf(m, "Statistics are not activated in this kernel\n");
#endif