vfs: don't use BKL in default_llseek

There are currently 191 users of default_llseek.
Nine of these are in device drivers that use the
big kernel lock. None of these ever touch
file->f_pos outside of llseek or file_pos_write.

Consequently, we never rely on the BKL
in the default_llseek function and can
replace that with i_mutex, which is also
used in generic_file_llseek.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Arnd Bergmann 2010-07-07 22:55:17 +02:00
parent 6038f373a3
commit ab91261f5c

View File

@ -124,7 +124,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
{
loff_t retval;
lock_kernel();
mutex_lock(&file->f_dentry->d_inode->i_mutex);
switch (origin) {
case SEEK_END:
offset += i_size_read(file->f_path.dentry->d_inode);
@ -145,7 +145,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
retval = offset;
}
out:
unlock_kernel();
mutex_unlock(&file->f_dentry->d_inode->i_mutex);
return retval;
}
EXPORT_SYMBOL(default_llseek);