tree 6898ca61ec49ae8d15fc8d48fa781d36c4a8fea8
parent be8d1a2ab98998d369c14c3deb600a31708a66c5
author Filipe Manana <fdmanana@suse.com> 1639666832 +0000
committer David Sterba <dsterba@suse.com> 1641561507 +0100

btrfs: respect the max size in the header when activating swap file

If we extended the size of a swapfile after its header was created (by the
mkswap utility) and then try to activate it, we will map the entire file
when activating the swap file, instead of limiting to the max size defined
in the swap file's header.

Currently test case generic/643 from fstests fails because we do not
respect that size limit defined in the swap file's header.

So fix this by not mapping file ranges beyond the max size defined in the
swap header.

This is the same type of bug that iomap used to have, and was fixed in
commit 36ca7943ac18ae ("mm/swap: consider max pages in
iomap_swapfile_add_extent").

Fixes: ed46ff3d423780 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-and-tested-by: Josef Bacik <josef@toxicpanda.com
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>