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Input: remove BKL, fix input_open_file() locking 

Holding the BKL in input_open_file seems pointless because it does not
protect against updates of input_table, and all open functions from the
underlying drivers have proper mutex locking.

This makes input_open_file take the input_mutex when accessing
the table and no lock when calling into the lower function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Arnd Bergmann 2010-03-09 20:38:48 -08:00 committed by Dmitry Torokhov
parent 77554b4d1f
commit 2f2177c8da
1 changed files with 10 additions and 8 deletions
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18
drivers/input/input.c
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@ -1879,35 +1879,37 @@ static int input_open_file(struct inode *inode, struct file *file)
const struct file_operations *old_fops, *new_fops = NULL;
int err;
lock_kernel();
err = mutex_lock_interruptible(&input_mutex);
if (err)
return err;
/* No load-on-demand here? */
handler = input_table[iminor(inode) >> 5];
if (!handler || !(new_fops = fops_get(handler->fops))) {
err = -ENODEV;
goto out;
}
if (handler)
new_fops = fops_get(handler->fops);
mutex_unlock(&input_mutex);
/*
* That's _really_ odd. Usually NULL ->open means "nothing special",
* not "no device". Oh, well...
*/
if (!new_fops->open) {
if (!new_fops || !new_fops->open) {
fops_put(new_fops);
err = -ENODEV;
goto out;
}
old_fops = file->f_op;
file->f_op = new_fops;
err = new_fops->open(inode, file);
if (err) {
fops_put(file->f_op);
file->f_op = fops_get(old_fops);
}
fops_put(old_fops);
out:
unlock_kernel();
return err;
}