3 files changed, 42 insertions, 9 deletions

diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 4f0ab88a1b31..e21b2f7f4159 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -100,8 +100,6 @@ enum kernfs_node_type {
 
 #define KERNFS_TYPE_MASK		0x000f
 #define KERNFS_FLAG_MASK		~KERNFS_TYPE_MASK
-#define KERNFS_MAX_USER_XATTRS		128
-#define KERNFS_USER_XATTR_SIZE_LIMIT	(128 << 10)
 
 enum kernfs_node_flag {
 	KERNFS_ACTIVATED	= 0x0010,
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index a8273b32e041..f6a2d3402d76 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -48,7 +48,7 @@ struct shmem_inode_info {
 	};
 	struct timespec64	i_crtime;	/* file creation time */
 	struct shared_policy	policy;		/* NUMA memory alloc policy */
-	struct simple_xattrs	xattrs;		/* list of xattrs */
+	struct simple_xattrs	*xattrs;	/* list of xattrs */
 	pgoff_t			fallocend;	/* highest fallocate endindex */
 	unsigned int		fsflags;	/* for FS_IOC_[SG]ETFLAGS */
 	atomic_t		stop_eviction;	/* hold when working on inode */
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 296b5ee5c979..8b6601367eae 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -16,6 +16,7 @@
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
+#include <linux/rhashtable-types.h>
 #include <linux/user_namespace.h>
 #include <uapi/linux/xattr.h>
 
@@ -106,31 +107,65 @@ static inline const char *xattr_prefix(const struct xattr_handler *handler)
 }
 
 struct simple_xattrs {
-	struct rb_root rb_root;
-	rwlock_t lock;
+	struct rhashtable ht;
 };
 
 struct simple_xattr {
-	struct rb_node rb_node;
+	struct rhash_head hash_node;
+	struct rcu_head rcu;
 	char *name;
 	size_t size;
 	char value[] __counted_by(size);
 };
 
-void simple_xattrs_init(struct simple_xattrs *xattrs);
+#define SIMPLE_XATTR_MAX_NR		128
+#define SIMPLE_XATTR_MAX_SIZE		(128 << 10)
+
+struct simple_xattr_limits {
+	atomic_t	nr_xattrs;	/* current user.* xattr count */
+	atomic_t	xattr_size;	/* current total user.* value bytes */
+};
+
+static inline void simple_xattr_limits_init(struct simple_xattr_limits *limits)
+{
+	atomic_set(&limits->nr_xattrs, 0);
+	atomic_set(&limits->xattr_size, 0);
+}
+
+int simple_xattrs_init(struct simple_xattrs *xattrs);
+struct simple_xattrs *simple_xattrs_alloc(void);
+struct simple_xattrs *simple_xattrs_lazy_alloc(struct simple_xattrs **xattrsp,
+					       const void *value, int flags);
 void simple_xattrs_free(struct simple_xattrs *xattrs, size_t *freed_space);
 size_t simple_xattr_space(const char *name, size_t size);
 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
 void simple_xattr_free(struct simple_xattr *xattr);
+void simple_xattr_free_rcu(struct simple_xattr *xattr);
 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
 		     void *buffer, size_t size);
 struct simple_xattr *simple_xattr_set(struct simple_xattrs *xattrs,
 				      const char *name, const void *value,
 				      size_t size, int flags);
+int simple_xattr_set_limited(struct simple_xattrs *xattrs,
+			     struct simple_xattr_limits *limits,
+			     const char *name, const void *value,
+			     size_t size, int flags);
 ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 			  char *buffer, size_t size);
-void simple_xattr_add(struct simple_xattrs *xattrs,
-		      struct simple_xattr *new_xattr);
+int simple_xattr_add(struct simple_xattrs *xattrs,
+		     struct simple_xattr *new_xattr);
 int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name);
 
+DEFINE_CLASS(simple_xattr,
+	     struct simple_xattr *,
+	     if (!IS_ERR_OR_NULL(_T)) simple_xattr_free(_T),
+	     simple_xattr_alloc(value, size),
+	     const void *value, size_t size)
+
+DEFINE_CLASS(simple_xattrs,
+            struct simple_xattrs *,
+            if (!IS_ERR_OR_NULL(_T)) { simple_xattrs_free(_T, NULL); kfree(_T); },
+            simple_xattrs_alloc(),
+            void)
+
 #endif	/* _LINUX_XATTR_H */