Re: [PATCH 16/16] vfs: return -EOPNOTSUPP for fscaps from vfs_*xattr()
From: Amir Goldstein <amir73il@gmail.com>
Date: 2023-11-30 06:10:27
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linux-fsdevel, linux-unionfs, lkml
On Wed, Nov 29, 2023 at 11:51 PM Seth Forshee (DigitalOcean) [off-list ref] wrote:
Now that the new vfs-level interfaces are fully supported and all code has been converted to use them, stop permitting use of the top-level vfs xattr interfaces for capabilities xattrs. Unlike with ACLs we still need to be able to work with fscaps xattrs using lower-level interfaces in a handful of places, so only use of the top-level xattr interfaces is restricted.
Can you explain why? Is there an inherent difference between ACLs and fscaps in that respect or is it just a matter of more work that needs to be done?
quoted hunk ↗ jump to hunk
Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> --- fs/xattr.c | 9 +++++++++ 1 file changed, 9 insertions(+)diff --git a/fs/xattr.c b/fs/xattr.c index 372644b15457..4b779779ad8c 100644 --- a/fs/xattr.c +++ b/fs/xattr.c@@ -540,6 +540,9 @@ vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, const void *orig_value = value; int error; + if (!strcmp(name, XATTR_NAME_CAPS)) + return -EOPNOTSUPP; +
It this is really not expected, then it should be an assert and please use an inline helper like is_posix_acl_xattr(): if (WARN_ON_ONCE(is_fscaps_xattr(name))) It wouldn't hurt to add those assertions to is_posix_acl_xattr() cases as well, but that is unrelated to your change. Thanks, Amir.