aboutsummaryrefslogtreecommitdiffstats
path: root/fs/anon_inodes.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/anon_inodes.c')
-rw-r--r--fs/anon_inodes.c109
1 files changed, 56 insertions, 53 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index f11e43ed907d..28d39fb84ae3 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -39,19 +39,6 @@ static const struct dentry_operations anon_inodefs_dentry_operations = {
39 .d_dname = anon_inodefs_dname, 39 .d_dname = anon_inodefs_dname,
40}; 40};
41 41
42static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
43 int flags, const char *dev_name, void *data)
44{
45 return mount_pseudo(fs_type, "anon_inode:", NULL,
46 &anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
47}
48
49static struct file_system_type anon_inode_fs_type = {
50 .name = "anon_inodefs",
51 .mount = anon_inodefs_mount,
52 .kill_sb = kill_anon_super,
53};
54
55/* 42/*
56 * nop .set_page_dirty method so that people can use .page_mkwrite on 43 * nop .set_page_dirty method so that people can use .page_mkwrite on
57 * anon inodes. 44 * anon inodes.
@@ -65,6 +52,62 @@ static const struct address_space_operations anon_aops = {
65 .set_page_dirty = anon_set_page_dirty, 52 .set_page_dirty = anon_set_page_dirty,
66}; 53};
67 54
55/*
56 * A single inode exists for all anon_inode files. Contrary to pipes,
57 * anon_inode inodes have no associated per-instance data, so we need
58 * only allocate one of them.
59 */
60static struct inode *anon_inode_mkinode(struct super_block *s)
61{
62 struct inode *inode = new_inode_pseudo(s);
63
64 if (!inode)
65 return ERR_PTR(-ENOMEM);
66
67 inode->i_ino = get_next_ino();
68 inode->i_fop = &anon_inode_fops;
69
70 inode->i_mapping->a_ops = &anon_aops;
71
72 /*
73 * Mark the inode dirty from the very beginning,
74 * that way it will never be moved to the dirty
75 * list because mark_inode_dirty() will think
76 * that it already _is_ on the dirty list.
77 */
78 inode->i_state = I_DIRTY;
79 inode->i_mode = S_IRUSR | S_IWUSR;
80 inode->i_uid = current_fsuid();
81 inode->i_gid = current_fsgid();
82 inode->i_flags |= S_PRIVATE;
83 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
84 return inode;
85}
86
87static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
88 int flags, const char *dev_name, void *data)
89{
90 struct dentry *root;
91 root = mount_pseudo(fs_type, "anon_inode:", NULL,
92 &anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
93 if (!IS_ERR(root)) {
94 struct super_block *s = root->d_sb;
95 anon_inode_inode = anon_inode_mkinode(s);
96 if (IS_ERR(anon_inode_inode)) {
97 dput(root);
98 deactivate_locked_super(s);
99 root = ERR_CAST(anon_inode_inode);
100 }
101 }
102 return root;
103}
104
105static struct file_system_type anon_inode_fs_type = {
106 .name = "anon_inodefs",
107 .mount = anon_inodefs_mount,
108 .kill_sb = kill_anon_super,
109};
110
68/** 111/**
69 * anon_inode_getfile - creates a new file instance by hooking it up to an 112 * anon_inode_getfile - creates a new file instance by hooking it up to an
70 * anonymous inode, and a dentry that describe the "class" 113 * anonymous inode, and a dentry that describe the "class"
@@ -180,38 +223,6 @@ err_put_unused_fd:
180} 223}
181EXPORT_SYMBOL_GPL(anon_inode_getfd); 224EXPORT_SYMBOL_GPL(anon_inode_getfd);
182 225
183/*
184 * A single inode exists for all anon_inode files. Contrary to pipes,
185 * anon_inode inodes have no associated per-instance data, so we need
186 * only allocate one of them.
187 */
188static struct inode *anon_inode_mkinode(void)
189{
190 struct inode *inode = new_inode_pseudo(anon_inode_mnt->mnt_sb);
191
192 if (!inode)
193 return ERR_PTR(-ENOMEM);
194
195 inode->i_ino = get_next_ino();
196 inode->i_fop = &anon_inode_fops;
197
198 inode->i_mapping->a_ops = &anon_aops;
199
200 /*
201 * Mark the inode dirty from the very beginning,
202 * that way it will never be moved to the dirty
203 * list because mark_inode_dirty() will think
204 * that it already _is_ on the dirty list.
205 */
206 inode->i_state = I_DIRTY;
207 inode->i_mode = S_IRUSR | S_IWUSR;
208 inode->i_uid = current_fsuid();
209 inode->i_gid = current_fsgid();
210 inode->i_flags |= S_PRIVATE;
211 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
212 return inode;
213}
214
215static int __init anon_inode_init(void) 226static int __init anon_inode_init(void)
216{ 227{
217 int error; 228 int error;
@@ -224,16 +235,8 @@ static int __init anon_inode_init(void)
224 error = PTR_ERR(anon_inode_mnt); 235 error = PTR_ERR(anon_inode_mnt);
225 goto err_unregister_filesystem; 236 goto err_unregister_filesystem;
226 } 237 }
227 anon_inode_inode = anon_inode_mkinode();
228 if (IS_ERR(anon_inode_inode)) {
229 error = PTR_ERR(anon_inode_inode);
230 goto err_mntput;
231 }
232
233 return 0; 238 return 0;
234 239
235err_mntput:
236 kern_unmount(anon_inode_mnt);
237err_unregister_filesystem: 240err_unregister_filesystem:
238 unregister_filesystem(&anon_inode_fs_type); 241 unregister_filesystem(&anon_inode_fs_type);
239err_exit: 242err_exit: