Commit | Line | Data |
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619daeee | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
6d66f5cd TH |
3 | * fs/sysfs/dir.c - sysfs core and dir operation implementation |
4 | * | |
5 | * Copyright (c) 2001-3 Patrick Mochel | |
6 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
7 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
8 | * | |
6d66f5cd | 9 | * Please see Documentation/filesystems/sysfs.txt for more information. |
1da177e4 LT |
10 | */ |
11 | ||
5d54f948 | 12 | #define pr_fmt(fmt) "sysfs: " fmt |
1da177e4 LT |
13 | |
14 | #include <linux/fs.h> | |
1da177e4 | 15 | #include <linux/kobject.h> |
c6f87733 | 16 | #include <linux/slab.h> |
1da177e4 LT |
17 | #include "sysfs.h" |
18 | ||
0cae60f9 | 19 | DEFINE_SPINLOCK(sysfs_symlink_target_lock); |
1da177e4 | 20 | |
324a56e1 | 21 | void sysfs_warn_dup(struct kernfs_node *parent, const char *name) |
d1c1459e | 22 | { |
3abb1d90 | 23 | char *buf; |
d1c1459e | 24 | |
3eef34ad TH |
25 | buf = kzalloc(PATH_MAX, GFP_KERNEL); |
26 | if (buf) | |
3abb1d90 | 27 | kernfs_path(parent, buf, PATH_MAX); |
d1c1459e | 28 | |
5d54f948 GKH |
29 | pr_warn("cannot create duplicate filename '%s/%s'\n", buf, name); |
30 | dump_stack(); | |
d1c1459e | 31 | |
3eef34ad | 32 | kfree(buf); |
d1c1459e TH |
33 | } |
34 | ||
1da177e4 | 35 | /** |
e34ff490 TH |
36 | * sysfs_create_dir_ns - create a directory for an object with a namespace tag |
37 | * @kobj: object we're creating directory for | |
38 | * @ns: the namespace tag to use | |
1da177e4 | 39 | */ |
e34ff490 | 40 | int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) |
1da177e4 | 41 | { |
324a56e1 | 42 | struct kernfs_node *parent, *kn; |
5f81880d DT |
43 | kuid_t uid; |
44 | kgid_t gid; | |
1da177e4 LT |
45 | |
46 | BUG_ON(!kobj); | |
47 | ||
90bc6135 | 48 | if (kobj->parent) |
324a56e1 | 49 | parent = kobj->parent->sd; |
1da177e4 | 50 | else |
324a56e1 | 51 | parent = sysfs_root_kn; |
1da177e4 | 52 | |
324a56e1 | 53 | if (!parent) |
3a198886 DW |
54 | return -ENOENT; |
55 | ||
5f81880d DT |
56 | kobject_get_ownership(kobj, &uid, &gid); |
57 | ||
bb8b9d09 | 58 | kn = kernfs_create_dir_ns(parent, kobject_name(kobj), |
5f81880d | 59 | S_IRWXU | S_IRUGO | S_IXUGO, uid, gid, |
488dee96 | 60 | kobj, ns); |
324a56e1 TH |
61 | if (IS_ERR(kn)) { |
62 | if (PTR_ERR(kn) == -EEXIST) | |
63 | sysfs_warn_dup(parent, kobject_name(kobj)); | |
64 | return PTR_ERR(kn); | |
93b2b8e4 TH |
65 | } |
66 | ||
324a56e1 | 67 | kobj->sd = kn; |
93b2b8e4 | 68 | return 0; |
1da177e4 LT |
69 | } |
70 | ||
b592fcfe EB |
71 | /** |
72 | * sysfs_remove_dir - remove an object's directory. | |
73 | * @kobj: object. | |
74 | * | |
75 | * The only thing special about this is that we remove any files in | |
76 | * the directory before we remove the directory, and we've inlined | |
77 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
78 | */ | |
1b18dc2b | 79 | void sysfs_remove_dir(struct kobject *kobj) |
b592fcfe | 80 | { |
324a56e1 | 81 | struct kernfs_node *kn = kobj->sd; |
aecdceda | 82 | |
0cae60f9 TH |
83 | /* |
84 | * In general, kboject owner is responsible for ensuring removal | |
85 | * doesn't race with other operations and sysfs doesn't provide any | |
86 | * protection; however, when @kobj is used as a symlink target, the | |
87 | * symlinking entity usually doesn't own @kobj and thus has no | |
324a56e1 TH |
88 | * control over removal. @kobj->sd may be removed anytime |
89 | * and symlink code may end up dereferencing an already freed node. | |
0cae60f9 | 90 | * |
324a56e1 TH |
91 | * sysfs_symlink_target_lock synchronizes @kobj->sd |
92 | * disassociation against symlink operations so that symlink code | |
93 | * can safely dereference @kobj->sd. | |
0cae60f9 TH |
94 | */ |
95 | spin_lock(&sysfs_symlink_target_lock); | |
608e266a | 96 | kobj->sd = NULL; |
0cae60f9 | 97 | spin_unlock(&sysfs_symlink_target_lock); |
aecdceda | 98 | |
324a56e1 | 99 | if (kn) { |
df23fc39 | 100 | WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR); |
324a56e1 | 101 | kernfs_remove(kn); |
250f7c3f | 102 | } |
1da177e4 LT |
103 | } |
104 | ||
e34ff490 TH |
105 | int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, |
106 | const void *new_ns) | |
ca1bab38 | 107 | { |
3eef34ad TH |
108 | struct kernfs_node *parent; |
109 | int ret; | |
3ff195b0 | 110 | |
3eef34ad TH |
111 | parent = kernfs_get_parent(kobj->sd); |
112 | ret = kernfs_rename_ns(kobj->sd, parent, new_name, new_ns); | |
113 | kernfs_put(parent); | |
114 | return ret; | |
ca1bab38 EB |
115 | } |
116 | ||
e34ff490 TH |
117 | int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, |
118 | const void *new_ns) | |
8a82472f | 119 | { |
324a56e1 TH |
120 | struct kernfs_node *kn = kobj->sd; |
121 | struct kernfs_node *new_parent; | |
8a82472f | 122 | |
324a56e1 TH |
123 | new_parent = new_parent_kobj && new_parent_kobj->sd ? |
124 | new_parent_kobj->sd : sysfs_root_kn; | |
51225039 | 125 | |
adc5e8b5 | 126 | return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); |
8a82472f | 127 | } |
87d2846f EB |
128 | |
129 | /** | |
130 | * sysfs_create_mount_point - create an always empty directory | |
131 | * @parent_kobj: kobject that will contain this always empty directory | |
132 | * @name: The name of the always empty directory to add | |
133 | */ | |
134 | int sysfs_create_mount_point(struct kobject *parent_kobj, const char *name) | |
135 | { | |
136 | struct kernfs_node *kn, *parent = parent_kobj->sd; | |
137 | ||
138 | kn = kernfs_create_empty_dir(parent, name); | |
139 | if (IS_ERR(kn)) { | |
140 | if (PTR_ERR(kn) == -EEXIST) | |
141 | sysfs_warn_dup(parent, name); | |
142 | return PTR_ERR(kn); | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(sysfs_create_mount_point); | |
148 | ||
149 | /** | |
150 | * sysfs_remove_mount_point - remove an always empty directory. | |
151 | * @parent_kobj: kobject that will contain this always empty directory | |
152 | * @name: The name of the always empty directory to remove | |
153 | * | |
154 | */ | |
155 | void sysfs_remove_mount_point(struct kobject *parent_kobj, const char *name) | |
156 | { | |
157 | struct kernfs_node *parent = parent_kobj->sd; | |
158 | ||
159 | kernfs_remove_by_name_ns(parent, name, NULL); | |
160 | } | |
161 | EXPORT_SYMBOL_GPL(sysfs_remove_mount_point); |