Miklos,
On Fri, Feb 21, 2020 at 7:01 PM Christoph Hellwig <hch@xxxxxx> wrote:
> There is no excuse to ever perform actions related to a specific handler
> directly from the generic xattr code as we have handler that understand
> the specific data in given attrs. As a nice sideeffect this removes
> tons of pointless boilerplate code.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
can you please review this change from an overlayfs point of view?
Thanks,
Andreas
> ---
> fs/posix_acl.c | 62 ++-------------------------------
> fs/xattr.c | 8 +----
> include/linux/posix_acl_xattr.h | 12 -------
> 3 files changed, 3 insertions(+), 79 deletions(-)
>
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 249672bf54fe..09f1b7d186f0 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -663,64 +663,6 @@ int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
> }
> EXPORT_SYMBOL(posix_acl_update_mode);
>
> -/*
> - * Fix up the uids and gids in posix acl extended attributes in place.
> - */
> -static void posix_acl_fix_xattr_userns(
> - struct user_namespace *to, struct user_namespace *from,
> - void *value, size_t size)
> -{
> - struct posix_acl_xattr_header *header = value;
> - struct posix_acl_xattr_entry *entry = (void *)(header + 1), *end;
> - int count;
> - kuid_t uid;
> - kgid_t gid;
> -
> - if (!value)
> - return;
> - if (size < sizeof(struct posix_acl_xattr_header))
> - return;
> - if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
> - return;
> -
> - count = posix_acl_xattr_count(size);
> - if (count < 0)
> - return;
> - if (count == 0)
> - return;
> -
> - for (end = entry + count; entry != end; entry++) {
> - switch(le16_to_cpu(entry->e_tag)) {
> - case ACL_USER:
> - uid = make_kuid(from, le32_to_cpu(entry->e_id));
> - entry->e_id = cpu_to_le32(from_kuid(to, uid));
> - break;
> - case ACL_GROUP:
> - gid = make_kgid(from, le32_to_cpu(entry->e_id));
> - entry->e_id = cpu_to_le32(from_kgid(to, gid));
> - break;
> - default:
> - break;
> - }
> - }
> -}
> -
> -void posix_acl_fix_xattr_from_user(void *value, size_t size)
> -{
> - struct user_namespace *user_ns = current_user_ns();
> - if (user_ns == &init_user_ns)
> - return;
> - posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
> -}
> -
> -void posix_acl_fix_xattr_to_user(void *value, size_t size)
> -{
> - struct user_namespace *user_ns = current_user_ns();
> - if (user_ns == &init_user_ns)
> - return;
> - posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
> -}
> -
> /*
> * Convert from extended attribute to in-memory representation.
> */
> @@ -851,7 +793,7 @@ posix_acl_xattr_get(const struct xattr_handler *handler,
> if (acl == NULL)
> return -ENODATA;
>
> - error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
> + error = posix_acl_to_xattr(current_user_ns(), acl, value, size);
> posix_acl_release(acl);
>
> return error;
> @@ -889,7 +831,7 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
> int ret;
>
> if (value) {
> - acl = posix_acl_from_xattr(&init_user_ns, value, size);
> + acl = posix_acl_from_xattr(current_user_ns(), value, size);
> if (IS_ERR(acl))
> return PTR_ERR(acl);
> }
> diff --git a/fs/xattr.c b/fs/xattr.c
> index 90dd78f0eb27..c31e9a9ea172 100644
> --- a/fs/xattr.c
> +++ b/fs/xattr.c
> @@ -437,10 +437,7 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value,
> error = -EFAULT;
> goto out;
> }
> - if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
> - (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
> - posix_acl_fix_xattr_from_user(kvalue, size);
> - else if (strcmp(kname, XATTR_NAME_CAPS) == 0) {
> + if (strcmp(kname, XATTR_NAME_CAPS) == 0) {
> error = cap_convert_nscap(d, &kvalue, size);
> if (error < 0)
> goto out;
> @@ -537,9 +534,6 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
>
> error = vfs_getxattr(d, kname, kvalue, size);
> if (error > 0) {
> - if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
> - (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
> - posix_acl_fix_xattr_to_user(kvalue, error);
> if (size && copy_to_user(value, kvalue, error))
> error = -EFAULT;
> } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
> diff --git a/include/linux/posix_acl_xattr.h b/include/linux/posix_acl_xattr.h
> index 2387709991b5..8f5e70a1bd05 100644
> --- a/include/linux/posix_acl_xattr.h
> +++ b/include/linux/posix_acl_xattr.h
> @@ -32,18 +32,6 @@ posix_acl_xattr_count(size_t size)
> return size / sizeof(struct posix_acl_xattr_entry);
> }
>
> -#ifdef CONFIG_FS_POSIX_ACL
> -void posix_acl_fix_xattr_from_user(void *value, size_t size);
> -void posix_acl_fix_xattr_to_user(void *value, size_t size);
> -#else
> -static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
> -{
> -}
> -static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
> -{
> -}
> -#endif
> -
> struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
> const void *value, size_t size);
> int posix_acl_to_xattr(struct user_namespace *user_ns,
> --
> 2.24.1
>
