Commit 9a45022a authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: allow swap activation to be interruptible 



During swap activation we iterate over the extents of a file, then do
several checks for each extent, some of which may take some significant
time such as checking if an extent is shared. Since a file can have
many thousands of extents, this can be a very slow operation and it's
currently not interruptible. I had a bug during development of a previous
patch that resulted in an infinite loop when iterating the extents, so
a core was busy looping and I couldn't cancel the operation, which is very
annoying and requires a reboot. So make the loop interruptible by checking
for fatal signals at the end of each iteration and stopping immediately if
there is one.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 03018e5d

fs/btrfs/inode.c

+5 −0
Original line number Diff line number Diff line
@@ -10073,6 +10073,11 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, 
			bsi.block_start = physical_block_start;

			bsi.block_len = len;

		}



		if (fatal_signal_pending(current)) {

			ret = -EINTR;

			goto out;

		}

	}



	if (bsi.block_len)