diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index af1608070cd5..61c98f03baa1 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -429,8 +429,9 @@ check_flags: no implementations. If your fs is not using generic_file_llseek, you need to acquire and release the appropriate locks in your ->llseek(). For many filesystems, it is probably safe to acquire the inode -mutex. Note some filesystems (i.e. remote ones) provide no -protection for i_size so you will need to use the BKL. +mutex or just to use i_size_read() instead. +Note: this does not protect the file->f_pos against concurrent modifications +since this is something the userspace has to take care about. Note: ext2_release() was *the* source of contention on fs-intensive loads and dropping BKL on ->release() helps to get rid of that (we still