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loop: split loop_control_ioctl

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Split loop_control_ioctl into a helper for each command.  This keeps the
code nicely separated for the upcoming locking changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-06-23 16:59:04 +02:00 committed by Jens Axboe
parent 4157fe0b3d
commit f9d107644a
1 changed files with 62 additions and 35 deletions
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97
drivers/block/loop.c
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@ -2397,8 +2397,51 @@ static void loop_probe(dev_t dev)
mutex_unlock(&loop_ctl_mutex);
}
static long loop_control_ioctl(struct file *file, unsigned int cmd,
unsigned long parm)
static int loop_control_add(int idx)
{
int ret;
ret = mutex_lock_killable(&loop_ctl_mutex);
if (ret)
return ret;
ret = loop_add(idx);
mutex_unlock(&loop_ctl_mutex);
return ret;
}
static int loop_control_remove(int idx)
{
struct loop_device *lo;
int ret;
ret = mutex_lock_killable(&loop_ctl_mutex);
if (ret)
return ret;
ret = loop_lookup(&lo, idx);
if (ret < 0)
goto out_unlock_ctrl;
ret = mutex_lock_killable(&lo->lo_mutex);
if (ret)
goto out_unlock_ctrl;
if (lo->lo_state != Lo_unbound ||
atomic_read(&lo->lo_refcnt) > 0) {
mutex_unlock(&lo->lo_mutex);
ret = -EBUSY;
goto out_unlock_ctrl;
}
lo->lo_state = Lo_deleting;
mutex_unlock(&lo->lo_mutex);
idr_remove(&loop_index_idr, lo->lo_number);
loop_remove(lo);
out_unlock_ctrl:
mutex_unlock(&loop_ctl_mutex);
return ret;
}
static int loop_control_get_free(int idx)
{
struct loop_device *lo;
int ret;
@ -2406,45 +2449,29 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
ret = mutex_lock_killable(&loop_ctl_mutex);
if (ret)
return ret;
ret = -ENOSYS;
switch (cmd) {
case LOOP_CTL_ADD:
ret = loop_add(parm);
break;
case LOOP_CTL_REMOVE:
ret = loop_lookup(&lo, parm);
if (ret < 0)
break;
ret = mutex_lock_killable(&lo->lo_mutex);
if (ret)
break;
if (lo->lo_state != Lo_unbound) {
ret = -EBUSY;
mutex_unlock(&lo->lo_mutex);
break;
}
if (atomic_read(&lo->lo_refcnt) > 0) {
ret = -EBUSY;
mutex_unlock(&lo->lo_mutex);
break;
}
lo->lo_state = Lo_deleting;
mutex_unlock(&lo->lo_mutex);
idr_remove(&loop_index_idr, lo->lo_number);
loop_remove(lo);
break;
case LOOP_CTL_GET_FREE:
ret = loop_lookup(&lo, -1);
if (ret >= 0)
break;
ret = loop_lookup(&lo, -1);
if (ret < 0)
ret = loop_add(-1);
}
mutex_unlock(&loop_ctl_mutex);
return ret;
}
static long loop_control_ioctl(struct file *file, unsigned int cmd,
unsigned long parm)
{
switch (cmd) {
case LOOP_CTL_ADD:
return loop_control_add(parm);
case LOOP_CTL_REMOVE:
return loop_control_remove(parm);
case LOOP_CTL_GET_FREE:
return loop_control_get_free(parm);
default:
return -ENOSYS;
}
}
static const struct file_operations loop_ctl_fops = {
.open = nonseekable_open,
.unlocked_ioctl = loop_control_ioctl,