xattr.h 3.9 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. File: linux/xattr.h
  4. Extended attributes handling.
  5. Copyright (C) 2001 by Andreas Gruenbacher <[email protected]>
  6. Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved.
  7. Copyright (c) 2004 Red Hat, Inc., James Morris <[email protected]>
  8. */
  9. #ifndef _LINUX_XATTR_H
  10. #define _LINUX_XATTR_H
  11. #include <linux/slab.h>
  12. #include <linux/types.h>
  13. #include <linux/spinlock.h>
  14. #include <linux/mm.h>
  15. #include <linux/user_namespace.h>
  16. #include <uapi/linux/xattr.h>
  17. struct inode;
  18. struct dentry;
  19. /*
  20. * struct xattr_handler: When @name is set, match attributes with exactly that
  21. * name. When @prefix is set instead, match attributes with that prefix and
  22. * with a non-empty suffix.
  23. */
  24. struct xattr_handler {
  25. const char *name;
  26. const char *prefix;
  27. int flags; /* fs private flags */
  28. bool (*list)(struct dentry *dentry);
  29. int (*get)(const struct xattr_handler *, struct dentry *dentry,
  30. struct inode *inode, const char *name, void *buffer,
  31. size_t size);
  32. int (*set)(const struct xattr_handler *,
  33. struct user_namespace *mnt_userns, struct dentry *dentry,
  34. struct inode *inode, const char *name, const void *buffer,
  35. size_t size, int flags);
  36. };
  37. const char *xattr_full_name(const struct xattr_handler *, const char *);
  38. struct xattr {
  39. const char *name;
  40. void *value;
  41. size_t value_len;
  42. };
  43. ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t);
  44. ssize_t vfs_getxattr(struct user_namespace *, struct dentry *, const char *,
  45. void *, size_t);
  46. ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
  47. int __vfs_setxattr(struct user_namespace *, struct dentry *, struct inode *,
  48. const char *, const void *, size_t, int);
  49. int __vfs_setxattr_noperm(struct user_namespace *, struct dentry *,
  50. const char *, const void *, size_t, int);
  51. int __vfs_setxattr_locked(struct user_namespace *, struct dentry *,
  52. const char *, const void *, size_t, int,
  53. struct inode **);
  54. int vfs_setxattr(struct user_namespace *, struct dentry *, const char *,
  55. const void *, size_t, int);
  56. int __vfs_removexattr(struct user_namespace *, struct dentry *, const char *);
  57. int __vfs_removexattr_locked(struct user_namespace *, struct dentry *,
  58. const char *, struct inode **);
  59. int vfs_removexattr(struct user_namespace *, struct dentry *, const char *);
  60. ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
  61. ssize_t vfs_getxattr_alloc(struct user_namespace *mnt_userns,
  62. struct dentry *dentry, const char *name,
  63. char **xattr_value, size_t size, gfp_t flags);
  64. int xattr_supported_namespace(struct inode *inode, const char *prefix);
  65. static inline const char *xattr_prefix(const struct xattr_handler *handler)
  66. {
  67. return handler->prefix ?: handler->name;
  68. }
  69. struct simple_xattrs {
  70. struct list_head head;
  71. spinlock_t lock;
  72. };
  73. struct simple_xattr {
  74. struct list_head list;
  75. char *name;
  76. size_t size;
  77. char value[];
  78. };
  79. /*
  80. * initialize the simple_xattrs structure
  81. */
  82. static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
  83. {
  84. INIT_LIST_HEAD(&xattrs->head);
  85. spin_lock_init(&xattrs->lock);
  86. }
  87. /*
  88. * free all the xattrs
  89. */
  90. static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
  91. {
  92. struct simple_xattr *xattr, *node;
  93. list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
  94. kfree(xattr->name);
  95. kvfree(xattr);
  96. }
  97. }
  98. struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
  99. int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
  100. void *buffer, size_t size);
  101. int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
  102. const void *value, size_t size, int flags,
  103. ssize_t *removed_size);
  104. ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
  105. size_t size);
  106. void simple_xattr_list_add(struct simple_xattrs *xattrs,
  107. struct simple_xattr *new_xattr);
  108. #endif /* _LINUX_XATTR_H */