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CAPI: Convert capi drivers rwlock into mutex
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Turn the lock protecting registered capi drivers into a mutex and apply
it consistently.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Jan Kiszka authored and David S. Miller committed Feb 17, 2010
1 parent 5225303 commit 9717fb8
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Showing 3 changed files with 27 additions and 32 deletions.
49 changes: 22 additions & 27 deletions drivers/isdn/capi/kcapi.c
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ static char capi_manufakturer[64] = "AVM Berlin";
#define NCCI2CTRL(ncci) (((ncci) >> 24) & 0x7f)

LIST_HEAD(capi_drivers);
DEFINE_RWLOCK(capi_drivers_list_lock);
DEFINE_MUTEX(capi_drivers_lock);

static DEFINE_RWLOCK(application_lock);
static DEFINE_MUTEX(controller_mutex);
Expand Down Expand Up @@ -540,11 +540,9 @@ EXPORT_SYMBOL(detach_capi_ctr);

void register_capi_driver(struct capi_driver *driver)
{
unsigned long flags;

write_lock_irqsave(&capi_drivers_list_lock, flags);
mutex_lock(&capi_drivers_lock);
list_add_tail(&driver->list, &capi_drivers);
write_unlock_irqrestore(&capi_drivers_list_lock, flags);
mutex_unlock(&capi_drivers_lock);
}

EXPORT_SYMBOL(register_capi_driver);
Expand All @@ -558,11 +556,9 @@ EXPORT_SYMBOL(register_capi_driver);

void unregister_capi_driver(struct capi_driver *driver)
{
unsigned long flags;

write_lock_irqsave(&capi_drivers_list_lock, flags);
mutex_lock(&capi_drivers_lock);
list_del(&driver->list);
write_unlock_irqrestore(&capi_drivers_list_lock, flags);
mutex_unlock(&capi_drivers_lock);
}

EXPORT_SYMBOL(unregister_capi_driver);
Expand Down Expand Up @@ -899,7 +895,6 @@ static int old_capi_manufacturer(unsigned int cmd, void __user *data)
struct capi_driver *driver = NULL;
capiloaddata ldata;
struct list_head *l;
unsigned long flags;
int retval;

switch (cmd) {
Expand All @@ -919,7 +914,8 @@ static int old_capi_manufacturer(unsigned int cmd, void __user *data)
cparams.irq = cdef.irq;
cparams.cardnr = cdef.cardnr;

read_lock_irqsave(&capi_drivers_list_lock, flags);
mutex_lock(&capi_drivers_lock);

switch (cdef.cardtype) {
case AVM_CARDTYPE_B1:
list_for_each(l, &capi_drivers) {
Expand All @@ -940,18 +936,15 @@ static int old_capi_manufacturer(unsigned int cmd, void __user *data)
break;
}
if (!driver) {
read_unlock_irqrestore(&capi_drivers_list_lock, flags);
printk(KERN_ERR "kcapi: driver not loaded.\n");
return -EIO;
}
if (!driver->add_card) {
read_unlock_irqrestore(&capi_drivers_list_lock, flags);
retval = -EIO;
} else if (!driver->add_card) {
printk(KERN_ERR "kcapi: driver has no add card function.\n");
return -EIO;
}
retval = -EIO;
} else
retval = driver->add_card(driver, &cparams);

retval = driver->add_card(driver, &cparams);
read_unlock_irqrestore(&capi_drivers_list_lock, flags);
mutex_unlock(&capi_drivers_lock);
return retval;

case AVMB1_LOAD:
Expand Down Expand Up @@ -1107,6 +1100,8 @@ int capi20_manufacturer(unsigned int cmd, void __user *data)
cparams.cardtype = 0;
cdef.driver[sizeof(cdef.driver)-1] = 0;

mutex_lock(&capi_drivers_lock);

list_for_each(l, &capi_drivers) {
driver = list_entry(l, struct capi_driver, list);
if (strcmp(driver->name, cdef.driver) == 0)
Expand All @@ -1115,15 +1110,15 @@ int capi20_manufacturer(unsigned int cmd, void __user *data)
if (driver == NULL) {
printk(KERN_ERR "kcapi: driver \"%s\" not loaded.\n",
cdef.driver);
return -ESRCH;
}

if (!driver->add_card) {
retval = -ESRCH;
} else if (!driver->add_card) {
printk(KERN_ERR "kcapi: driver \"%s\" has no add card function.\n", cdef.driver);
return -EIO;
}
retval = -EIO;
} else
retval = driver->add_card(driver, &cparams);

return driver->add_card(driver, &cparams);
mutex_unlock(&capi_drivers_lock);
return retval;
}

default:
Expand Down
2 changes: 1 addition & 1 deletion drivers/isdn/capi/kcapi.h
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ enum {
};

extern struct list_head capi_drivers;
extern rwlock_t capi_drivers_list_lock;
extern struct mutex capi_drivers_lock;

extern struct capi20_appl *capi_applications[CAPI_MAXAPPL];
extern struct capi_ctr *capi_controller[CAPI_MAXCONTR];
Expand Down
8 changes: 4 additions & 4 deletions drivers/isdn/capi/kcapi_proc.c
Original file line number Diff line number Diff line change
Expand Up @@ -238,9 +238,9 @@ static const struct file_operations proc_applstats_ops = {
// ---------------------------------------------------------------------------

static void *capi_driver_start(struct seq_file *seq, loff_t *pos)
__acquires(&capi_drivers_list_lock)
__acquires(&capi_drivers_lock)
{
read_lock(&capi_drivers_list_lock);
mutex_lock(&capi_drivers_lock);
return seq_list_start(&capi_drivers, *pos);
}

Expand All @@ -250,9 +250,9 @@ static void *capi_driver_next(struct seq_file *seq, void *v, loff_t *pos)
}

static void capi_driver_stop(struct seq_file *seq, void *v)
__releases(&capi_drivers_list_lock)
__releases(&capi_drivers_lock)
{
read_unlock(&capi_drivers_list_lock);
mutex_unlock(&capi_drivers_lock);
}

static int capi_driver_show(struct seq_file *seq, void *v)
Expand Down

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