Re: [PATCH 5.15 1/3] ext4: add two helper functions extent_logical_end() and pa_logical_end()

[Greg KH <gregkh@linuxfoundation.org>]

On Sat, Oct 28, 2023 at 02:47:47PM +0800, Baokun Li wrote:
> commit 43bbddc067883d94de7a43d5756a295439fbe37d upstream.

Why just 5.15 and older?  What about 6.1.y?  We can't take patches only
for older stable kernels, otherwise you will have a regression when you
upgrade.  Please send a series for 6.1.y if you wish to have us apply
these for older kernels.

> When we use lstart + len to calculate the end of free extent or prealloc
> space, it may exceed the maximum value of 4294967295(0xffffffff) supported
> by ext4_lblk_t and cause overflow, which may lead to various problems.
> 
> Therefore, we add two helper functions, extent_logical_end() and
> pa_logical_end(), to limit the type of end to loff_t, and also convert
> lstart to loff_t for calculation to avoid overflow.
> 
> Signed-off-by: Baokun Li <libaokun1@huawei.com>
> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@huawei.com
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> 
> Conflicts:
> 	fs/ext4/mballoc.c
> 

Note, the "Conflicts:" stuff isn't needed.

thanks,

greg k-h