From: Jeff Layton Date: Tue, 12 Aug 2014 12:03:49 +0000 (-0400) Subject: locks: don't reuse file_lock in __posix_lock_file X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b84d49f9440b2b039828f3eb114e4bd4ebeb0c54;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git locks: don't reuse file_lock in __posix_lock_file Currently in the case where a new file lock completely replaces the old one, we end up overwriting the existing lock with the new info. This means that we have to call fl_release_private inside i_lock. Change the code to instead copy the info to new_fl, insert that lock into the correct spot and then delete the old lock. In a later patch, we'll defer the freeing of the old lock until after the i_lock has been dropped. Acked-by: J. Bruce Fields Signed-off-by: Jeff Layton --- diff --git a/fs/locks.c b/fs/locks.c index 2c2d4f5022a7..7dd4defb4d8d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1022,18 +1022,21 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str locks_delete_lock(before); continue; } - /* Replace the old lock with the new one. - * Wake up anybody waiting for the old one, - * as the change in lock type might satisfy - * their needs. + /* + * Replace the old lock with new_fl, and + * remove the old one. It's safe to do the + * insert here since we know that we won't be + * using new_fl later, and that the lock is + * just replacing an existing lock. */ - locks_wake_up_blocks(fl); - fl->fl_start = request->fl_start; - fl->fl_end = request->fl_end; - fl->fl_type = request->fl_type; - locks_release_private(fl); - locks_copy_private(fl, request); - request = fl; + error = -ENOLCK; + if (!new_fl) + goto out; + locks_copy_lock(new_fl, request); + request = new_fl; + new_fl = NULL; + locks_delete_lock(before); + locks_insert_lock(before, request); added = true; } }