Re: [PATCH 04/18] fs: add generic xattr_acl handlers

Jan Kara
2013-12-02T20:59:34Z

On Sun 01-12-13 03:59:07, Christoph Hellwig wrote:
> With the ->set_acl inode operation we can implement the Posix ACL
> xattr handlers in generic code instead of duplicating them all
> over the tree.
Looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>

Honza

>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> fs/xattr_acl.c | 95 +++++++++++++++++++++++++++++++++++++++
> include/linux/posix_acl_xattr.h | 3 ++
> 2 files changed, 98 insertions(+)
>
> diff --git a/fs/xattr_acl.c b/fs/xattr_acl.c
> index 9fbea87..932ec76 100644
> --- a/fs/xattr_acl.c
> +++ b/fs/xattr_acl.c
> @@ -10,6 +10,7 @@
> #include <linux/posix_acl_xattr.h>
> #include <linux/gfp.h>
> #include <linux/user_namespace.h>
> +#include <linux/xattr.h>
>
> /*
> * Fix up the uids and gids in posix acl extended attributes in place.
> @@ -178,3 +179,97 @@ posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
> return real_size;
> }
> EXPORT_SYMBOL (posix_acl_to_xattr);
> +
> +static int
> +posix_acl_xattr_get(struct dentry *dentry, const char *name,
> + void *value, size_t size, int type)
> +{
> + struct posix_acl *acl;
> + int error;
> +
> + if (!IS_POSIXACL(dentry->d_inode))
> + return -EOPNOTSUPP;
> +
> + acl = get_acl(dentry->d_inode, type);
> + if (IS_ERR(acl))
> + return PTR_ERR(acl);
> + if (acl == NULL)
> + return -ENODATA;
> +
> + error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
> + posix_acl_release(acl);
> +
> + return error;
> +}
> +
> +static int
> +posix_acl_xattr_set(struct dentry *dentry, const char *name,
> + const void *value, size_t size, int flags, int type)
> +{
> + struct inode *inode = dentry->d_inode;
> + struct posix_acl *acl = NULL;
> + int ret;
> +
> + if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
> + return value ? -EACCES : 0;
> + if (!inode_owner_or_capable(inode))
> + return -EPERM;
> + if (!IS_POSIXACL(inode))
> + return -EOPNOTSUPP;
> +
> + if (value) {
> + acl = posix_acl_from_xattr(&init_user_ns, value, size);
> + if (IS_ERR(acl))
> + return PTR_ERR(acl);
> +
> + if (acl) {
> + ret = posix_acl_valid(acl);
> + if (ret)
> + goto out;
> + }
> + }
> +
> + ret = inode->i_op->set_acl(inode, acl, type);
> +out:
> + posix_acl_release(acl);
> + return ret;
> +}
> +
> +static size_t
> +posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
> + const char *name, size_t name_len, int type)
> +{
> + const char *xname;
> + size_t size;
> +
> + if (!IS_POSIXACL(dentry->d_inode))
> + return -EOPNOTSUPP;
> +
> + if (type == ACL_TYPE_ACCESS)
> + xname = POSIX_ACL_XATTR_ACCESS;
> + else
> + xname = POSIX_ACL_XATTR_DEFAULT;
> +
> + size = strlen(xname) + 1;
> + if (list && size <= list_size)
> + memcpy(list, xname, size);
> + return size;
> +}
> +
> +const struct xattr_handler posix_acl_access_xattr_handler = {
> + .prefix = POSIX_ACL_XATTR_ACCESS,
> + .flags = ACL_TYPE_ACCESS,
> + .list = posix_acl_xattr_list,
> + .get = posix_acl_xattr_get,
> + .set = posix_acl_xattr_set,
> +};
> +EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
> +
> +const struct xattr_handler posix_acl_default_xattr_handler = {
> + .prefix = POSIX_ACL_XATTR_DEFAULT,
> + .flags = ACL_TYPE_DEFAULT,
> + .list = posix_acl_xattr_list,
> + .get = posix_acl_xattr_get,
> + .set = posix_acl_xattr_set,
> +};
> +EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
> diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h
> index ad93ad0..6f14ee2 100644
> --- a/include/linux/posix_acl_xattr.h
> +++ b/include/linux/posix_acl_xattr.h
> @@ -69,4 +69,7 @@ struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
> int posix_acl_to_xattr(struct user_namespace *user_ns,
> const struct posix_acl *acl, void *buffer, size_t size);
>
> +extern const struct xattr_handler posix_acl_access_xattr_handler;
> +extern const struct xattr_handler posix_acl_default_xattr_handler;
> +
> #endif /* _POSIX_ACL_XATTR_H */
> --
> 1.7.10.4
>
>
> --
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--
Jan Kara <jack@suse.cz>
SUSE Labs, CR