btrfs: allow swap activation to be interruptible

[ Upstream commit 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 ]

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: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

This commit is contained in:

Filipe Manana

2024-12-09 16:31:41 +00:00

committed by

Greg Kroah-Hartman

parent 4ac8e8bf70

commit 93d7d212c6

1 changed files with 5 additions and 0 deletions

									
										fs/btrfs/inode.c
									
		+5
		
												View File
												
				@@ -10056,6 +10056,11 @@ 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)