From 2aeccbe957d0d2b9fbb2a236e53a955097e2a9ce Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 20 Dec 2013 05:16:40 -0800 Subject: [PATCH] fs: add generic xattr_acl handlers 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. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Al Viro --- fs/posix_acl.c | 102 ++++++++++++++++++++++++++++++++ include/linux/posix_acl_xattr.h | 3 + 2 files changed, 105 insertions(+) diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 30524de49a6b..e699b076cdd8 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -611,3 +612,104 @@ 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; + if (S_ISLNK(dentry->d_inode->i_mode)) + 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 (!IS_POSIXACL(inode)) + return -EOPNOTSUPP; + if (!inode->i_op->set_acl) + return -EOPNOTSUPP; + + if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) + return value ? -EACCES : 0; + if (!inode_owner_or_capable(inode)) + return -EPERM; + + 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 (S_ISLNK(dentry->d_inode->i_mode)) + 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 ad93ad0f1db0..6f14ee295822 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 */ -- 2.30.2