xref: /linux/fs/xfs/libxfs/xfs_parent.h (revision 4f77c3462308c62ffe7129cc18b9ac937f44b5a5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2022-2024 Oracle.
4  * All Rights Reserved.
5  */
6 #ifndef	__XFS_PARENT_H__
7 #define	__XFS_PARENT_H__
8 
9 /* Metadata validators */
10 bool xfs_parent_namecheck(unsigned int attr_flags, const void *name,
11 		size_t length);
12 bool xfs_parent_valuecheck(struct xfs_mount *mp, const void *value,
13 		size_t valuelen);
14 
15 xfs_dahash_t xfs_parent_hashval(struct xfs_mount *mp, const uint8_t *name,
16 		int namelen, xfs_ino_t parent_ino);
17 xfs_dahash_t xfs_parent_hashattr(struct xfs_mount *mp, const uint8_t *name,
18 		int namelen, const void *value, int valuelen);
19 
20 /* Initializes a xfs_parent_rec to be stored as an attribute name. */
21 static inline void
22 xfs_parent_rec_init(
23 	struct xfs_parent_rec	*rec,
24 	xfs_ino_t		ino,
25 	uint32_t		gen)
26 {
27 	rec->p_ino = cpu_to_be64(ino);
28 	rec->p_gen = cpu_to_be32(gen);
29 }
30 
31 /* Initializes a xfs_parent_rec to be stored as an attribute name. */
32 static inline void
33 xfs_inode_to_parent_rec(
34 	struct xfs_parent_rec	*rec,
35 	const struct xfs_inode	*dp)
36 {
37 	xfs_parent_rec_init(rec, dp->i_ino, VFS_IC(dp)->i_generation);
38 }
39 
40 extern struct kmem_cache	*xfs_parent_args_cache;
41 
42 /*
43  * Parent pointer information needed to pass around the deferred xattr update
44  * machinery.
45  */
46 struct xfs_parent_args {
47 	struct xfs_parent_rec	rec;
48 	struct xfs_parent_rec	new_rec;
49 	struct xfs_da_args	args;
50 };
51 
52 /*
53  * Start a parent pointer update by allocating the context object we need to
54  * perform a parent pointer update.
55  */
56 static inline int
57 xfs_parent_start(
58 	struct xfs_mount	*mp,
59 	struct xfs_parent_args	**ppargsp)
60 {
61 	if (!xfs_has_parent(mp)) {
62 		*ppargsp = NULL;
63 		return 0;
64 	}
65 
66 	*ppargsp = kmem_cache_zalloc(xfs_parent_args_cache, GFP_KERNEL);
67 	if (!*ppargsp)
68 		return -ENOMEM;
69 	return 0;
70 }
71 
72 /* Finish a parent pointer update by freeing the context object. */
73 static inline void
74 xfs_parent_finish(
75 	struct xfs_mount	*mp,
76 	struct xfs_parent_args	*ppargs)
77 {
78 	if (ppargs)
79 		kmem_cache_free(xfs_parent_args_cache, ppargs);
80 }
81 
82 int xfs_parent_addname(struct xfs_trans *tp, struct xfs_parent_args *ppargs,
83 		struct xfs_inode *dp, const struct xfs_name *parent_name,
84 		struct xfs_inode *child);
85 int xfs_parent_removename(struct xfs_trans *tp, struct xfs_parent_args *ppargs,
86 		struct xfs_inode *dp, const struct xfs_name *parent_name,
87 		struct xfs_inode *child);
88 int xfs_parent_replacename(struct xfs_trans *tp,
89 		struct xfs_parent_args *ppargs,
90 		struct xfs_inode *old_dp, const struct xfs_name *old_name,
91 		struct xfs_inode *new_dp, const struct xfs_name *new_name,
92 		struct xfs_inode *child);
93 
94 int xfs_parent_from_attr(struct xfs_mount *mp, unsigned int attr_flags,
95 		const unsigned char *name, unsigned int namelen,
96 		const void *value, unsigned int valuelen,
97 		xfs_ino_t *parent_ino, uint32_t *parent_gen);
98 
99 /* Repair functions */
100 int xfs_parent_lookup(struct xfs_trans *tp, struct xfs_inode *ip,
101 		const struct xfs_name *name, struct xfs_parent_rec *pptr,
102 		struct xfs_da_args *scratch);
103 int xfs_parent_set(struct xfs_inode *ip, xfs_ino_t owner,
104 		const struct xfs_name *name, struct xfs_parent_rec *pptr,
105 		struct xfs_da_args *scratch);
106 int xfs_parent_unset(struct xfs_inode *ip, xfs_ino_t owner,
107 		const struct xfs_name *name, struct xfs_parent_rec *pptr,
108 		struct xfs_da_args *scratch);
109 
110 #endif /* __XFS_PARENT_H__ */
111