diff options
Diffstat (limited to 'fs/configfs/inode.c')
-rw-r--r-- | fs/configfs/inode.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c new file mode 100644 index 000000000000..6b274c6d428f --- /dev/null +++ b/fs/configfs/inode.c | |||
@@ -0,0 +1,162 @@ | |||
1 | /* -*- mode: c; c-basic-offset: 8; -*- | ||
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | ||
3 | * | ||
4 | * inode.c - basic inode and dentry operations. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU General Public | ||
8 | * License as published by the Free Software Foundation; either | ||
9 | * version 2 of the License, or (at your option) any later version. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
14 | * General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public | ||
17 | * License along with this program; if not, write to the | ||
18 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
19 | * Boston, MA 021110-1307, USA. | ||
20 | * | ||
21 | * Based on sysfs: | ||
22 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | ||
23 | * | ||
24 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | ||
25 | * | ||
26 | * Please see Documentation/filesystems/configfs.txt for more information. | ||
27 | */ | ||
28 | |||
29 | #undef DEBUG | ||
30 | |||
31 | #include <linux/pagemap.h> | ||
32 | #include <linux/namei.h> | ||
33 | #include <linux/backing-dev.h> | ||
34 | |||
35 | #include <linux/configfs.h> | ||
36 | #include "configfs_internal.h" | ||
37 | |||
38 | extern struct super_block * configfs_sb; | ||
39 | |||
40 | static struct address_space_operations configfs_aops = { | ||
41 | .readpage = simple_readpage, | ||
42 | .prepare_write = simple_prepare_write, | ||
43 | .commit_write = simple_commit_write | ||
44 | }; | ||
45 | |||
46 | static struct backing_dev_info configfs_backing_dev_info = { | ||
47 | .ra_pages = 0, /* No readahead */ | ||
48 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, | ||
49 | }; | ||
50 | |||
51 | struct inode * configfs_new_inode(mode_t mode) | ||
52 | { | ||
53 | struct inode * inode = new_inode(configfs_sb); | ||
54 | if (inode) { | ||
55 | inode->i_mode = mode; | ||
56 | inode->i_uid = 0; | ||
57 | inode->i_gid = 0; | ||
58 | inode->i_blksize = PAGE_CACHE_SIZE; | ||
59 | inode->i_blocks = 0; | ||
60 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | ||
61 | inode->i_mapping->a_ops = &configfs_aops; | ||
62 | inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; | ||
63 | } | ||
64 | return inode; | ||
65 | } | ||
66 | |||
67 | int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) | ||
68 | { | ||
69 | int error = 0; | ||
70 | struct inode * inode = NULL; | ||
71 | if (dentry) { | ||
72 | if (!dentry->d_inode) { | ||
73 | if ((inode = configfs_new_inode(mode))) { | ||
74 | if (dentry->d_parent && dentry->d_parent->d_inode) { | ||
75 | struct inode *p_inode = dentry->d_parent->d_inode; | ||
76 | p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; | ||
77 | } | ||
78 | goto Proceed; | ||
79 | } | ||
80 | else | ||
81 | error = -ENOMEM; | ||
82 | } else | ||
83 | error = -EEXIST; | ||
84 | } else | ||
85 | error = -ENOENT; | ||
86 | goto Done; | ||
87 | |||
88 | Proceed: | ||
89 | if (init) | ||
90 | error = init(inode); | ||
91 | if (!error) { | ||
92 | d_instantiate(dentry, inode); | ||
93 | if (S_ISDIR(mode) || S_ISLNK(mode)) | ||
94 | dget(dentry); /* pin link and directory dentries in core */ | ||
95 | } else | ||
96 | iput(inode); | ||
97 | Done: | ||
98 | return error; | ||
99 | } | ||
100 | |||
101 | /* | ||
102 | * Get the name for corresponding element represented by the given configfs_dirent | ||
103 | */ | ||
104 | const unsigned char * configfs_get_name(struct configfs_dirent *sd) | ||
105 | { | ||
106 | struct attribute * attr; | ||
107 | |||
108 | if (!sd || !sd->s_element) | ||
109 | BUG(); | ||
110 | |||
111 | /* These always have a dentry, so use that */ | ||
112 | if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK)) | ||
113 | return sd->s_dentry->d_name.name; | ||
114 | |||
115 | if (sd->s_type & CONFIGFS_ITEM_ATTR) { | ||
116 | attr = sd->s_element; | ||
117 | return attr->name; | ||
118 | } | ||
119 | return NULL; | ||
120 | } | ||
121 | |||
122 | |||
123 | /* | ||
124 | * Unhashes the dentry corresponding to given configfs_dirent | ||
125 | * Called with parent inode's i_sem held. | ||
126 | */ | ||
127 | void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) | ||
128 | { | ||
129 | struct dentry * dentry = sd->s_dentry; | ||
130 | |||
131 | if (dentry) { | ||
132 | spin_lock(&dcache_lock); | ||
133 | if (!(d_unhashed(dentry) && dentry->d_inode)) { | ||
134 | dget_locked(dentry); | ||
135 | __d_drop(dentry); | ||
136 | spin_unlock(&dcache_lock); | ||
137 | simple_unlink(parent->d_inode, dentry); | ||
138 | } else | ||
139 | spin_unlock(&dcache_lock); | ||
140 | } | ||
141 | } | ||
142 | |||
143 | void configfs_hash_and_remove(struct dentry * dir, const char * name) | ||
144 | { | ||
145 | struct configfs_dirent * sd; | ||
146 | struct configfs_dirent * parent_sd = dir->d_fsdata; | ||
147 | |||
148 | down(&dir->d_inode->i_sem); | ||
149 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | ||
150 | if (!sd->s_element) | ||
151 | continue; | ||
152 | if (!strcmp(configfs_get_name(sd), name)) { | ||
153 | list_del_init(&sd->s_sibling); | ||
154 | configfs_drop_dentry(sd, dir); | ||
155 | configfs_put(sd); | ||
156 | break; | ||
157 | } | ||
158 | } | ||
159 | up(&dir->d_inode->i_sem); | ||
160 | } | ||
161 | |||
162 | |||