From 98e9cb5711c68223f0e4d5201b9a6add255ec550 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Wed, 2 Dec 2015 14:44:36 +0100 Subject: vfs: Distinguish between full xattr names and proper prefixes Add an additional "name" field to struct xattr_handler. When the name is set, the handler matches attributes with exactly that name. When the prefix is set instead, the handler matches attributes with the given prefix and with a non-empty suffix. This patch should avoid bugs like the one fixed in commit c361016a in the future. Signed-off-by: Andreas Gruenbacher Reviewed-by: James Morris Signed-off-by: Al Viro --- include/linux/xattr.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/linux/xattr.h') diff --git a/include/linux/xattr.h b/include/linux/xattr.h index 45fa3456a0cc..03c847fb6cc1 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -19,7 +19,13 @@ struct inode; struct dentry; +/* + * struct xattr_handler: When @name is set, match attributes with exactly that + * name. When @prefix is set instead, match attributes with that prefix and + * with a non-empty suffix. + */ struct xattr_handler { + const char *name; const char *prefix; int flags; /* fs private flags */ size_t (*list)(const struct xattr_handler *, struct dentry *dentry, @@ -54,6 +60,11 @@ int generic_removexattr(struct dentry *dentry, const char *name); ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, size_t size, gfp_t flags); +static inline const char *xattr_prefix(const struct xattr_handler *handler) +{ + return handler->prefix ?: handler->name; +} + struct simple_xattrs { struct list_head head; spinlock_t lock; -- cgit v1.2.3-59-g8ed1b