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8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/fs.h>
12#include <linux/pagemap.h>
13#include <linux/mount.h>
14#include <linux/namei.h>
15#include <linux/gfp.h>
16#include <linux/fs_context.h>
17#include "internal.h"
18
19
20static struct dentry *afs_mntpt_lookup(struct inode *dir,
21 struct dentry *dentry,
22 unsigned int flags);
23static int afs_mntpt_open(struct inode *inode, struct file *file);
24static void afs_mntpt_expiry_timed_out(struct work_struct *work);
25
26const struct file_operations afs_mntpt_file_operations = {
27 .open = afs_mntpt_open,
28 .llseek = noop_llseek,
29};
30
31const struct inode_operations afs_mntpt_inode_operations = {
32 .lookup = afs_mntpt_lookup,
33 .readlink = page_readlink,
34 .getattr = afs_getattr,
35 .listxattr = afs_listxattr,
36};
37
38const struct inode_operations afs_autocell_inode_operations = {
39 .getattr = afs_getattr,
40};
41
42static LIST_HEAD(afs_vfsmounts);
43static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out);
44
45static unsigned long afs_mntpt_expiry_timeout = 10 * 60;
46
47static const char afs_root_volume[] = "root.cell";
48
49
50
51
52static struct dentry *afs_mntpt_lookup(struct inode *dir,
53 struct dentry *dentry,
54 unsigned int flags)
55{
56 _enter("%p,%p{%pd2}", dir, dentry, dentry);
57 return ERR_PTR(-EREMOTE);
58}
59
60
61
62
63static int afs_mntpt_open(struct inode *inode, struct file *file)
64{
65 _enter("%p,%p{%pD2}", inode, file, file);
66 return -EREMOTE;
67}
68
69
70
71
72static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
73{
74 struct afs_fs_context *ctx = fc->fs_private;
75 struct afs_super_info *src_as = AFS_FS_S(mntpt->d_sb);
76 struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt));
77 struct afs_cell *cell;
78 const char *p;
79 int ret;
80
81 if (fc->net_ns != src_as->net_ns) {
82 put_net(fc->net_ns);
83 fc->net_ns = get_net(src_as->net_ns);
84 }
85
86 if (src_as->volume && src_as->volume->type == AFSVL_RWVOL) {
87 ctx->type = AFSVL_RWVOL;
88 ctx->force = true;
89 }
90 if (ctx->cell) {
91 afs_put_cell(ctx->net, ctx->cell);
92 ctx->cell = NULL;
93 }
94 if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
95
96 unsigned size = mntpt->d_name.len;
97
98 if (size < 2)
99 return -ENOENT;
100
101 p = mntpt->d_name.name;
102 if (mntpt->d_name.name[0] == '.') {
103 size--;
104 p++;
105 ctx->type = AFSVL_RWVOL;
106 ctx->force = true;
107 }
108 if (size > AFS_MAXCELLNAME)
109 return -ENAMETOOLONG;
110
111 cell = afs_lookup_cell(ctx->net, p, size, NULL, false);
112 if (IS_ERR(cell)) {
113 pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt);
114 return PTR_ERR(cell);
115 }
116 ctx->cell = cell;
117
118 ctx->volname = afs_root_volume;
119 ctx->volnamesz = sizeof(afs_root_volume) - 1;
120 } else {
121
122 struct page *page;
123 loff_t size = i_size_read(d_inode(mntpt));
124 char *buf;
125
126 if (src_as->cell)
127 ctx->cell = afs_get_cell(src_as->cell);
128
129 if (size > PAGE_SIZE - 1)
130 return -EINVAL;
131
132 page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL);
133 if (IS_ERR(page))
134 return PTR_ERR(page);
135
136 if (PageError(page)) {
137 ret = afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt);
138 put_page(page);
139 return ret;
140 }
141
142 buf = kmap(page);
143 ret = vfs_parse_fs_string(fc, "source", buf, size);
144 kunmap(page);
145 put_page(page);
146 if (ret < 0)
147 return ret;
148 }
149
150 return 0;
151}
152
153
154
155
156static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
157{
158 struct fs_context *fc;
159 struct vfsmount *mnt;
160 int ret;
161
162 BUG_ON(!d_inode(mntpt));
163
164 fc = fs_context_for_submount(&afs_fs_type, mntpt);
165 if (IS_ERR(fc))
166 return ERR_CAST(fc);
167
168 ret = afs_mntpt_set_params(fc, mntpt);
169 if (!ret)
170 mnt = fc_mount(fc);
171 else
172 mnt = ERR_PTR(ret);
173
174 put_fs_context(fc);
175 return mnt;
176}
177
178
179
180
181struct vfsmount *afs_d_automount(struct path *path)
182{
183 struct vfsmount *newmnt;
184
185 _enter("{%pd}", path->dentry);
186
187 newmnt = afs_mntpt_do_automount(path->dentry);
188 if (IS_ERR(newmnt))
189 return newmnt;
190
191 mntget(newmnt);
192 mnt_set_expiry(newmnt, &afs_vfsmounts);
193 queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
194 afs_mntpt_expiry_timeout * HZ);
195 _leave(" = %p", newmnt);
196 return newmnt;
197}
198
199
200
201
202static void afs_mntpt_expiry_timed_out(struct work_struct *work)
203{
204 _enter("");
205
206 if (!list_empty(&afs_vfsmounts)) {
207 mark_mounts_for_expiry(&afs_vfsmounts);
208 queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
209 afs_mntpt_expiry_timeout * HZ);
210 }
211
212 _leave("");
213}
214
215
216
217
218void afs_mntpt_kill_timer(void)
219{
220 _enter("");
221
222 ASSERT(list_empty(&afs_vfsmounts));
223 cancel_delayed_work_sync(&afs_mntpt_expiry_timer);
224}
225