diff options
| author | Dae S. Kim <dae@velatum.com> | 2013-02-27 17:05:14 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-27 19:10:21 -0800 |
| commit | 3c94ce6f48f484bbc4dba83c0ed1f98f5e10957c (patch) | |
| tree | 0c475e8b2ab3a9e5b3e70f0a4dcd12f7ac46d514 | |
| parent | f2afae4629d74287aaac39d0532aac5819e77e70 (diff) | |
drivers/char/misc.c:misc_register(): do not loop on misc_list unconditionally
If the minor number is assigned dynamically, there is no need to search
for misc->minor in misc_list, since misc->minor == MISC_DYNAMIC_MINOR.
[akpm@linux-foundation.org: reduce scope of local `c']
Signed-off-by: Dae S. Kim <dae@velatum.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/char/misc.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 522136d4084..190d4423653 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -183,19 +183,12 @@ static const struct file_operations misc_fops = { int misc_register(struct miscdevice * misc) { - struct miscdevice *c; dev_t dev; int err = 0; INIT_LIST_HEAD(&misc->list); mutex_lock(&misc_mtx); - list_for_each_entry(c, &misc_list, list) { - if (c->minor == misc->minor) { - mutex_unlock(&misc_mtx); - return -EBUSY; - } - } if (misc->minor == MISC_DYNAMIC_MINOR) { int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS); @@ -205,6 +198,15 @@ int misc_register(struct miscdevice * misc) } misc->minor = DYNAMIC_MINORS - i - 1; set_bit(i, misc_minors); + } else { + struct miscdevice *c; + + list_for_each_entry(c, &misc_list, list) { + if (c->minor == misc->minor) { + mutex_unlock(&misc_mtx); + return -EBUSY; + } + } } dev = MKDEV(MISC_MAJOR, misc->minor); |