Re: [PATCH 18/20] staging: lustre: llite: Remove filtering of seclabel xattr

From: James Simmons
Date: Thu Jul 27 2017 - 15:35:48 EST



> From: Robin Humble <plaguedbypenguins@xxxxxxxxx>
>
> The security.capability xattr is used to implement File
> Capabilities in recent Linux versions. Capabilities are a
> fine grained approach to granting executables elevated
> privileges. eg. /bin/ping can have capabilities
> cap_net_admin, cap_net_raw+ep instead of being setuid root.
>
> This xattr has long been filtered out by llite, initially for
> stability reasons (b15587), and later over performance
> concerns as this xattr is read for every file with eg.
> 'ls --color'. Since LU-2869 xattr's are cached on clients,
> alleviating most performance concerns.
>
> Removing llite's filtering of the security.capability xattr
> enables using Lustre as a root filesystem, which is used on
> some large clusters.

The commit message for this patch is incorrect. Some how it got
mixed up with another patch which I missed in this push. Please
drop this patch and I will resent the correct patches later.

> Signed-off-by: Robin Humble <plaguedbypenguins@xxxxxxxxx>
> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-9562
> Reviewed-on: https://review.whamcloud.com/27292
> Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx>
> Reviewed-by: Sebastien Buisson <sbuisson@xxxxxxx>
> Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
> Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
> ---
> drivers/staging/lustre/lustre/llite/file.c | 58 ++++++++++++++++++++++
> .../staging/lustre/lustre/llite/llite_internal.h | 4 ++
> drivers/staging/lustre/lustre/llite/namei.c | 6 +++
> 3 files changed, 68 insertions(+)
>
> diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
> index 215479a..a324580 100644
> --- a/drivers/staging/lustre/lustre/llite/file.c
> +++ b/drivers/staging/lustre/lustre/llite/file.c
> @@ -3040,6 +3040,61 @@ struct posix_acl *ll_get_acl(struct inode *inode, int type)
> return acl;
> }
>
> +#ifdef CONFIG_FS_POSIX_ACL
> +int ll_set_acl(struct inode *inode, struct posix_acl *acl, int type)
> +{
> + const char *name = NULL;
> + char *value = NULL;
> + size_t size = 0;
> + int rc = 0;
> +
> + switch (type) {
> + case ACL_TYPE_ACCESS:
> + if (acl) {
> + rc = posix_acl_update_mode(inode, &inode->i_mode, &acl);
> + if (rc)
> + goto out;
> + }
> + name = XATTR_NAME_POSIX_ACL_ACCESS;
> + break;
> + case ACL_TYPE_DEFAULT:
> + if (!S_ISDIR(inode->i_mode)) {
> + rc = acl ? -EACCES : 0;
> + goto out;
> + }
> + name = XATTR_NAME_POSIX_ACL_DEFAULT;
> + break;
> + default:
> + rc = -EINVAL;
> + goto out;
> + }
> +
> + if (acl) {
> + size = posix_acl_xattr_size(acl->a_count);
> + value = kmalloc(size, GFP_NOFS);
> + if (!value) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
> + if (rc < 0)
> + goto out_free;
> + }
> +
> + /* dentry is only used for *.lov attributes so it's safe to be NULL */
> + rc = __vfs_setxattr(NULL, inode, name, value, size, XATTR_CREATE);
> +out_free:
> + kfree(value);
> +out:
> + if (!rc)
> + set_cached_acl(inode, type, acl);
> + else
> + forget_cached_acl(inode, type);
> + return rc;
> +}
> +#endif /* CONFIG_FS_POSIX_ACL */
> +
> int ll_inode_permission(struct inode *inode, int mask)
> {
> struct ll_sb_info *sbi;
> @@ -3162,6 +3217,9 @@ int ll_inode_permission(struct inode *inode, int mask)
> .listxattr = ll_listxattr,
> .fiemap = ll_fiemap,
> .get_acl = ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> + .set_acl = ll_set_acl,
> +#endif
> };
>
> /* dynamic ioctl number support routines */
> diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
> index cd3311a..b3374bc 100644
> --- a/drivers/staging/lustre/lustre/llite/llite_internal.h
> +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
> @@ -752,6 +752,10 @@ enum ldlm_mode ll_take_md_lock(struct inode *inode, __u64 bits,
> int ll_getattr(const struct path *path, struct kstat *stat,
> u32 request_mask, unsigned int flags);
> struct posix_acl *ll_get_acl(struct inode *inode, int type);
> +#ifdef CONFIG_FS_POSIX_ACL
> +int ll_set_acl(struct inode *inode, struct posix_acl *acl, int type);
> +#endif /* CONFIG_FS_POSIX_ACL */
> +
> int ll_migrate(struct inode *parent, struct file *file, int mdtidx,
> const char *name, int namelen);
> int ll_get_fid_by_name(struct inode *parent, const char *name,
> diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
> index a208a8b..14dccbe 100644
> --- a/drivers/staging/lustre/lustre/llite/namei.c
> +++ b/drivers/staging/lustre/lustre/llite/namei.c
> @@ -1187,6 +1187,9 @@ static int ll_rename(struct inode *src, struct dentry *src_dchild,
> .permission = ll_inode_permission,
> .listxattr = ll_listxattr,
> .get_acl = ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> + .set_acl = ll_set_acl,
> +#endif
> };
>
> const struct inode_operations ll_special_inode_operations = {
> @@ -1195,4 +1198,7 @@ static int ll_rename(struct inode *src, struct dentry *src_dchild,
> .permission = ll_inode_permission,
> .listxattr = ll_listxattr,
> .get_acl = ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> + .set_acl = ll_set_acl,
> +#endif
> };
> --
> 1.8.3.1
>
>