>>>>> "Guillaume" == Guillaume Thouvenin <guillaume.thouvenin@polymtl.ca> writes:
Guillaume> I implemented the ioctl as follow:
Guillaume> int my_ioctl(...) {
Guillaume> ...
Guillaume> switch(cmd) {
Guillaume> case REMOVE_AN_ITEM:
Guillaume> spin_lock_irq(&my_lock);
Guillaume> update_my_structure();
Guillaume> spin_unlock_irq(&my_lock);
Guillaume> break;
Guillaume> ....
Guillaume> }
Guillaume> }
Guillaume> Function update_my_structure() remove an item from a list
Guillaume> of items and if the list is empty, it dumps information
Guillaume> about this list in a file. So, in this function I call
Guillaume> filp_open() if list is empty. The problem is that you can
Guillaume> not call filp_open() if you are in a spinlock because irq
Guillaume> must be enable.
Guillaume> So my question is how can you open a file if you are in a
Guillaume> spin_lock_irq()?
Don't.
Do
switch (cmd)
{
case REMOVE_AN_ITEM:
spin_lock_irq (&my_lock);
is_empty = update_my_structure ();
spin_unlock_irq (&my_lock);
if (is_empty)
dump_stuff_to_file ();
break;
which is not very good either. Better return information that the
list is empty to the caller and let it meddle with files from
userspace.
~velco
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