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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; |
1da177e4 LT |
43 | |
44 | BUG_ON(!kobj); | |
45 | ||
90bc6135 | 46 | if (kobj->parent) |
324a56e1 | 47 | parent = kobj->parent->sd; |
1da177e4 | 48 | else |
324a56e1 | 49 | parent = sysfs_root_kn; |
1da177e4 | 50 | |
324a56e1 | 51 | if (!parent) |
3a198886 DW |
52 | return -ENOENT; |
53 | ||
bb8b9d09 TH |
54 | kn = kernfs_create_dir_ns(parent, kobject_name(kobj), |
55 | S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns); | |
324a56e1 TH |
56 | if (IS_ERR(kn)) { |
57 | if (PTR_ERR(kn) == -EEXIST) | |
58 | sysfs_warn_dup(parent, kobject_name(kobj)); | |
59 | return PTR_ERR(kn); | |
93b2b8e4 TH |
60 | } |
61 | ||
324a56e1 | 62 | kobj->sd = kn; |
93b2b8e4 | 63 | return 0; |
1da177e4 LT |
64 | } |
65 | ||
b592fcfe EB |
66 | /** |
67 | * sysfs_remove_dir - remove an object's directory. | |
68 | * @kobj: object. | |
69 | * | |
70 | * The only thing special about this is that we remove any files in | |
71 | * the directory before we remove the directory, and we've inlined | |
72 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
73 | */ | |
1b18dc2b | 74 | void sysfs_remove_dir(struct kobject *kobj) |
b592fcfe | 75 | { |
324a56e1 | 76 | struct kernfs_node *kn = kobj->sd; |
aecdceda | 77 | |
0cae60f9 TH |
78 | /* |
79 | * In general, kboject owner is responsible for ensuring removal | |
80 | * doesn't race with other operations and sysfs doesn't provide any | |
81 | * protection; however, when @kobj is used as a symlink target, the | |
82 | * symlinking entity usually doesn't own @kobj and thus has no | |
324a56e1 TH |
83 | * control over removal. @kobj->sd may be removed anytime |
84 | * and symlink code may end up dereferencing an already freed node. | |
0cae60f9 | 85 | * |
324a56e1 TH |
86 | * sysfs_symlink_target_lock synchronizes @kobj->sd |
87 | * disassociation against symlink operations so that symlink code | |
88 | * can safely dereference @kobj->sd. | |
0cae60f9 TH |
89 | */ |
90 | spin_lock(&sysfs_symlink_target_lock); | |
608e266a | 91 | kobj->sd = NULL; |
0cae60f9 | 92 | spin_unlock(&sysfs_symlink_target_lock); |
aecdceda | 93 | |
324a56e1 | 94 | if (kn) { |
df23fc39 | 95 | WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR); |
324a56e1 | 96 | kernfs_remove(kn); |
250f7c3f | 97 | } |
1da177e4 LT |
98 | } |
99 | ||
e34ff490 TH |
100 | int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, |
101 | const void *new_ns) | |
ca1bab38 | 102 | { |
3eef34ad TH |
103 | struct kernfs_node *parent; |
104 | int ret; | |
3ff195b0 | 105 | |
3eef34ad TH |
106 | parent = kernfs_get_parent(kobj->sd); |
107 | ret = kernfs_rename_ns(kobj->sd, parent, new_name, new_ns); | |
108 | kernfs_put(parent); | |
109 | return ret; | |
ca1bab38 EB |
110 | } |
111 | ||
e34ff490 TH |
112 | int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, |
113 | const void *new_ns) | |
8a82472f | 114 | { |
324a56e1 TH |
115 | struct kernfs_node *kn = kobj->sd; |
116 | struct kernfs_node *new_parent; | |
8a82472f | 117 | |
324a56e1 TH |
118 | new_parent = new_parent_kobj && new_parent_kobj->sd ? |
119 | new_parent_kobj->sd : sysfs_root_kn; | |
51225039 | 120 | |
adc5e8b5 | 121 | return kernfs_rename_ns(kn, new_parent, kn->name, new_ns); |
8a82472f | 122 | } |
87d2846f EB |
123 | |
124 | /** | |
125 | * sysfs_create_mount_point - create an always empty directory | |
126 | * @parent_kobj: kobject that will contain this always empty directory | |
127 | * @name: The name of the always empty directory to add | |
128 | */ | |
129 | int sysfs_create_mount_point(struct kobject *parent_kobj, const char *name) | |
130 | { | |
131 | struct kernfs_node *kn, *parent = parent_kobj->sd; | |
132 | ||
133 | kn = kernfs_create_empty_dir(parent, name); | |
134 | if (IS_ERR(kn)) { | |
135 | if (PTR_ERR(kn) == -EEXIST) | |
136 | sysfs_warn_dup(parent, name); | |
137 | return PTR_ERR(kn); | |
138 | } | |
139 | ||
140 | return 0; | |
141 | } | |
142 | EXPORT_SYMBOL_GPL(sysfs_create_mount_point); | |
143 | ||
144 | /** | |
145 | * sysfs_remove_mount_point - remove an always empty directory. | |
146 | * @parent_kobj: kobject that will contain this always empty directory | |
147 | * @name: The name of the always empty directory to remove | |
148 | * | |
149 | */ | |
150 | void sysfs_remove_mount_point(struct kobject *parent_kobj, const char *name) | |
151 | { | |
152 | struct kernfs_node *parent = parent_kobj->sd; | |
153 | ||
154 | kernfs_remove_by_name_ns(parent, name, NULL); | |
155 | } | |
156 | EXPORT_SYMBOL_GPL(sysfs_remove_mount_point); |