include/linux/xattr.h

Source file repositories/reference/linux-study-clean/include/linux/xattr.h

File Facts

System
Linux kernel
Corpus path
include/linux/xattr.h
Extension
.h
Size
5916 bytes
Lines
173
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct xattr_handler {
	const char *name;
	const char *prefix;
	int flags;      /* fs private flags */
	bool (*list)(struct dentry *dentry);
	int (*get)(const struct xattr_handler *, struct dentry *dentry,
		   struct inode *inode, const char *name, void *buffer,
		   size_t size);
	int (*set)(const struct xattr_handler *,
		   struct mnt_idmap *idmap, struct dentry *dentry,
		   struct inode *inode, const char *name, const void *buffer,
		   size_t size, int flags);
};

/**
 * xattr_handler_can_list - check whether xattr can be listed
 * @handler: handler for this type of xattr
 * @dentry: dentry whose inode xattr to list
 *
 * Determine whether the xattr associated with @dentry can be listed given
 * @handler.
 *
 * Return: true if xattr can be listed, false if not.
 */
static inline bool xattr_handler_can_list(const struct xattr_handler *handler,
					  struct dentry *dentry)
{
	return handler && (!handler->list || handler->list(dentry));
}

const char *xattr_full_name(const struct xattr_handler *, const char *);

struct xattr {
	const char *name;
	void *value;
	size_t value_len;
};

ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct mnt_idmap *, struct dentry *, const char *,
		     void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr(struct mnt_idmap *, struct dentry *, struct inode *,
		   const char *, const void *, size_t, int);
int __vfs_setxattr_noperm(struct mnt_idmap *, struct dentry *,
			  const char *, const void *, size_t, int);
int __vfs_setxattr_locked(struct mnt_idmap *, struct dentry *,
			  const char *, const void *, size_t, int,
			  struct delegated_inode *);
int vfs_setxattr(struct mnt_idmap *, struct dentry *, const char *,
		 const void *, size_t, int);
int __vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *);
int __vfs_removexattr_locked(struct mnt_idmap *, struct dentry *,
			     const char *, struct delegated_inode *);
int vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *);

ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
int vfs_getxattr_alloc(struct mnt_idmap *idmap,
		       struct dentry *dentry, const char *name,
		       char **xattr_value, size_t size, gfp_t flags);

int xattr_supports_user_prefix(struct inode *inode);

static inline const char *xattr_prefix(const struct xattr_handler *handler)
{
	return handler->prefix ?: handler->name;
}

struct simple_xattr_cache {
	struct rhashtable *ht;
};

struct simple_xattr {
	struct rhash_head hash_node;
	struct list_head *parent;
	struct list_head node;
	struct rcu_head rcu;
	char *name;
	size_t size;
	char value[] __counted_by(size);
};

#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 */
};

Annotation

Implementation Notes