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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/sysfs/inode.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/sysfs/inode.c')
-rw-r--r--fs/sysfs/inode.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
new file mode 100644
index 000000000000..aff7b2dfa8ee
--- /dev/null
+++ b/fs/sysfs/inode.c
@@ -0,0 +1,165 @@
1/*
2 * inode.c - basic inode and dentry operations.
3 *
4 * sysfs is Copyright (c) 2001-3 Patrick Mochel
5 *
6 * Please see Documentation/filesystems/sysfs.txt for more information.
7 */
8
9#undef DEBUG
10
11#include <linux/pagemap.h>
12#include <linux/namei.h>
13#include <linux/backing-dev.h>
14#include "sysfs.h"
15
16extern struct super_block * sysfs_sb;
17
18static struct address_space_operations sysfs_aops = {
19 .readpage = simple_readpage,
20 .prepare_write = simple_prepare_write,
21 .commit_write = simple_commit_write
22};
23
24static struct backing_dev_info sysfs_backing_dev_info = {
25 .ra_pages = 0, /* No readahead */
26 .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
27};
28
29struct inode * sysfs_new_inode(mode_t mode)
30{
31 struct inode * inode = new_inode(sysfs_sb);
32 if (inode) {
33 inode->i_mode = mode;
34 inode->i_uid = 0;
35 inode->i_gid = 0;
36 inode->i_blksize = PAGE_CACHE_SIZE;
37 inode->i_blocks = 0;
38 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
39 inode->i_mapping->a_ops = &sysfs_aops;
40 inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
41 }
42 return inode;
43}
44
45int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
46{
47 int error = 0;
48 struct inode * inode = NULL;
49 if (dentry) {
50 if (!dentry->d_inode) {
51 if ((inode = sysfs_new_inode(mode))) {
52 if (dentry->d_parent && dentry->d_parent->d_inode) {
53 struct inode *p_inode = dentry->d_parent->d_inode;
54 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
55 }
56 goto Proceed;
57 }
58 else
59 error = -ENOMEM;
60 } else
61 error = -EEXIST;
62 } else
63 error = -ENOENT;
64 goto Done;
65
66 Proceed:
67 if (init)
68 error = init(inode);
69 if (!error) {
70 d_instantiate(dentry, inode);
71 if (S_ISDIR(mode))
72 dget(dentry); /* pin only directory dentry in core */
73 } else
74 iput(inode);
75 Done:
76 return error;
77}
78
79struct dentry * sysfs_get_dentry(struct dentry * parent, const char * name)
80{
81 struct qstr qstr;
82
83 qstr.name = name;
84 qstr.len = strlen(name);
85 qstr.hash = full_name_hash(name,qstr.len);
86 return lookup_hash(&qstr,parent);
87}
88
89/*
90 * Get the name for corresponding element represented by the given sysfs_dirent
91 */
92const unsigned char * sysfs_get_name(struct sysfs_dirent *sd)
93{
94 struct attribute * attr;
95 struct bin_attribute * bin_attr;
96 struct sysfs_symlink * sl;
97
98 if (!sd || !sd->s_element)
99 BUG();
100
101 switch (sd->s_type) {
102 case SYSFS_DIR:
103 /* Always have a dentry so use that */
104 return sd->s_dentry->d_name.name;
105
106 case SYSFS_KOBJ_ATTR:
107 attr = sd->s_element;
108 return attr->name;
109
110 case SYSFS_KOBJ_BIN_ATTR:
111 bin_attr = sd->s_element;
112 return bin_attr->attr.name;
113
114 case SYSFS_KOBJ_LINK:
115 sl = sd->s_element;
116 return sl->link_name;
117 }
118 return NULL;
119}
120
121
122/*
123 * Unhashes the dentry corresponding to given sysfs_dirent
124 * Called with parent inode's i_sem held.
125 */
126void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
127{
128 struct dentry * dentry = sd->s_dentry;
129
130 if (dentry) {
131 spin_lock(&dcache_lock);
132 spin_lock(&dentry->d_lock);
133 if (!(d_unhashed(dentry) && dentry->d_inode)) {
134 dget_locked(dentry);
135 __d_drop(dentry);
136 spin_unlock(&dentry->d_lock);
137 spin_unlock(&dcache_lock);
138 simple_unlink(parent->d_inode, dentry);
139 } else {
140 spin_unlock(&dentry->d_lock);
141 spin_unlock(&dcache_lock);
142 }
143 }
144}
145
146void sysfs_hash_and_remove(struct dentry * dir, const char * name)
147{
148 struct sysfs_dirent * sd;
149 struct sysfs_dirent * parent_sd = dir->d_fsdata;
150
151 down(&dir->d_inode->i_sem);
152 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
153 if (!sd->s_element)
154 continue;
155 if (!strcmp(sysfs_get_name(sd), name)) {
156 list_del_init(&sd->s_sibling);
157 sysfs_drop_dentry(sd, dir);
158 sysfs_put(sd);
159 break;
160 }
161 }
162 up(&dir->d_inode->i_sem);
163}
164
165