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>
diff --git a/fs/read_write.c b/fs/read_write.c
index 74e3658..fd09f61 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -124,7 +124,7 @@
{
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 @@
retval = offset;
}
out:
- unlock_kernel();
+ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
return retval;
}
EXPORT_SYMBOL(default_llseek);