Commit 14b9d090 authored by David Howells's avatar David Howells
Browse files

cachefiles: Explain checks in a comment 



Add a comment to explain the checks that cachefiles is making of the
backing filesystem[1].

Suggested-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/568749bd7cc02908ecf6f3d6a611b6f9cf5c4afd.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/164251405621.3435901.771439791811515914.stgit@warthog.procyon.org.uk/ # v1
parent b64a3314

fs/cachefiles/cache.c

+7 −1
Original line number Original line Diff line number Diff line
@@ -49,7 +49,13 @@ int cachefiles_add_cache(struct cachefiles_cache *cache) 
		goto error_unsupported;

		goto error_unsupported;

	}

	}





	/* check parameters */

	/* Check features of the backing filesystem:

	 * - Directories must support looking up and directory creation

	 * - We use xattrs to store metadata

	 * - We need to be able to query the amount of space available

	 * - We want to be able to sync the filesystem when stopping the cache

	 * - We use DIO to/from pages, so the blocksize mustn't be too big.

	 */

	ret = -EOPNOTSUPP;

	ret = -EOPNOTSUPP;

	if (d_is_negative(root) ||

	if (d_is_negative(root) ||

	    !d_backing_inode(root)->i_op->lookup ||

	    !d_backing_inode(root)->i_op->lookup ||