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1/*
2 * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
3 *
4 * In fact, that's a piece of procfs; it's *almost* isolated from
5 * the rest of fs/proc, but has rather close relationships with
6 * fs/namespace.c, thus here instead of fs/proc
7 *
8 */
9#include <linux/mnt_namespace.h>
10#include <linux/nsproxy.h>
11#include <linux/security.h>
12#include <linux/fs_struct.h>
13#include "proc/internal.h" /* only for get_proc_task() in ->open() */
14
15#include "pnode.h"
16#include "internal.h"
17
18static unsigned mounts_poll(struct file *file, poll_table *wait)
19{
20 struct seq_file *m = file->private_data;
21 struct proc_mounts *p = m->private;
22 struct mnt_namespace *ns = p->ns;
23 unsigned res = POLLIN | POLLRDNORM;
24 int event;
25
26 poll_wait(file, &p->ns->poll, wait);
27
28 event = ACCESS_ONCE(ns->event);
29 if (m->poll_event != event) {
30 m->poll_event = event;
31 res |= POLLERR | POLLPRI;
32 }
33
34 return res;
35}
36
37struct proc_fs_info {
38 int flag;
39 const char *str;
40};
41
42static int show_sb_opts(struct seq_file *m, struct super_block *sb)
43{
44 static const struct proc_fs_info fs_info[] = {
45 { MS_SYNCHRONOUS, ",sync" },
46 { MS_DIRSYNC, ",dirsync" },
47 { MS_MANDLOCK, ",mand" },
48 { MS_LAZYTIME, ",lazytime" },
49 { 0, NULL }
50 };
51 const struct proc_fs_info *fs_infop;
52
53 for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
54 if (sb->s_flags & fs_infop->flag)
55 seq_puts(m, fs_infop->str);
56 }
57
58 return security_sb_show_options(m, sb);
59}
60
61static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
62{
63 static const struct proc_fs_info mnt_info[] = {
64 { MNT_NOSUID, ",nosuid" },
65 { MNT_NODEV, ",nodev" },
66 { MNT_NOEXEC, ",noexec" },
67 { MNT_NOATIME, ",noatime" },
68 { MNT_NODIRATIME, ",nodiratime" },
69 { MNT_RELATIME, ",relatime" },
70 { 0, NULL }
71 };
72 const struct proc_fs_info *fs_infop;
73
74 for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) {
75 if (mnt->mnt_flags & fs_infop->flag)
76 seq_puts(m, fs_infop->str);
77 }
78}
79
80static inline void mangle(struct seq_file *m, const char *s)
81{
82 seq_escape(m, s, " \t\n\\");
83}
84
85static void show_type(struct seq_file *m, struct super_block *sb)
86{
87 mangle(m, sb->s_type->name);
88 if (sb->s_subtype && sb->s_subtype[0]) {
89 seq_putc(m, '.');
90 mangle(m, sb->s_subtype);
91 }
92}
93
94static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
95{
96 struct proc_mounts *p = m->private;
97 struct mount *r = real_mount(mnt);
98 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
99 struct super_block *sb = mnt_path.dentry->d_sb;
100 int err;
101
102 if (sb->s_op->show_devname) {
103 err = sb->s_op->show_devname(m, mnt_path.dentry);
104 if (err)
105 goto out;
106 } else {
107 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
108 }
109 seq_putc(m, ' ');
110 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
111 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
112 if (err)
113 goto out;
114 seq_putc(m, ' ');
115 show_type(m, sb);
116 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
117 err = show_sb_opts(m, sb);
118 if (err)
119 goto out;
120 show_mnt_opts(m, mnt);
121 if (sb->s_op->show_options)
122 err = sb->s_op->show_options(m, mnt_path.dentry);
123 seq_puts(m, " 0 0\n");
124out:
125 return err;
126}
127
128static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
129{
130 struct proc_mounts *p = m->private;
131 struct mount *r = real_mount(mnt);
132 struct super_block *sb = mnt->mnt_sb;
133 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
134 int err;
135
136 seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
137 MAJOR(sb->s_dev), MINOR(sb->s_dev));
138 if (sb->s_op->show_path) {
139 err = sb->s_op->show_path(m, mnt->mnt_root);
140 if (err)
141 goto out;
142 } else {
143 seq_dentry(m, mnt->mnt_root, " \t\n\\");
144 }
145 seq_putc(m, ' ');
146
147 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
148 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
149 if (err)
150 goto out;
151
152 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
153 show_mnt_opts(m, mnt);
154
155 /* Tagged fields ("foo:X" or "bar") */
156 if (IS_MNT_SHARED(r))
157 seq_printf(m, " shared:%i", r->mnt_group_id);
158 if (IS_MNT_SLAVE(r)) {
159 int master = r->mnt_master->mnt_group_id;
160 int dom = get_dominating_id(r, &p->root);
161 seq_printf(m, " master:%i", master);
162 if (dom && dom != master)
163 seq_printf(m, " propagate_from:%i", dom);
164 }
165 if (IS_MNT_UNBINDABLE(r))
166 seq_puts(m, " unbindable");
167
168 /* Filesystem specific data */
169 seq_puts(m, " - ");
170 show_type(m, sb);
171 seq_putc(m, ' ');
172 if (sb->s_op->show_devname) {
173 err = sb->s_op->show_devname(m, mnt->mnt_root);
174 if (err)
175 goto out;
176 } else {
177 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
178 }
179 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
180 err = show_sb_opts(m, sb);
181 if (err)
182 goto out;
183 if (sb->s_op->show_options)
184 err = sb->s_op->show_options(m, mnt->mnt_root);
185 seq_putc(m, '\n');
186out:
187 return err;
188}
189
190static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
191{
192 struct proc_mounts *p = m->private;
193 struct mount *r = real_mount(mnt);
194 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
195 struct super_block *sb = mnt_path.dentry->d_sb;
196 int err;
197
198 /* device */
199 if (sb->s_op->show_devname) {
200 seq_puts(m, "device ");
201 err = sb->s_op->show_devname(m, mnt_path.dentry);
202 if (err)
203 goto out;
204 } else {
205 if (r->mnt_devname) {
206 seq_puts(m, "device ");
207 mangle(m, r->mnt_devname);
208 } else
209 seq_puts(m, "no device");
210 }
211
212 /* mount point */
213 seq_puts(m, " mounted on ");
214 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
215 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
216 if (err)
217 goto out;
218 seq_putc(m, ' ');
219
220 /* file system type */
221 seq_puts(m, "with fstype ");
222 show_type(m, sb);
223
224 /* optional statistics */
225 if (sb->s_op->show_stats) {
226 seq_putc(m, ' ');
227 err = sb->s_op->show_stats(m, mnt_path.dentry);
228 }
229
230 seq_putc(m, '\n');
231out:
232 return err;
233}
234
235static int mounts_open_common(struct inode *inode, struct file *file,
236 int (*show)(struct seq_file *, struct vfsmount *))
237{
238 struct task_struct *task = get_proc_task(inode);
239 struct nsproxy *nsp;
240 struct mnt_namespace *ns = NULL;
241 struct path root;
242 struct proc_mounts *p;
243 struct seq_file *m;
244 int ret = -EINVAL;
245
246 if (!task)
247 goto err;
248
249 task_lock(task);
250 nsp = task->nsproxy;
251 if (!nsp || !nsp->mnt_ns) {
252 task_unlock(task);
253 put_task_struct(task);
254 goto err;
255 }
256 ns = nsp->mnt_ns;
257 get_mnt_ns(ns);
258 if (!task->fs) {
259 task_unlock(task);
260 put_task_struct(task);
261 ret = -ENOENT;
262 goto err_put_ns;
263 }
264 get_fs_root(task->fs, &root);
265 task_unlock(task);
266 put_task_struct(task);
267
268 ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
269 if (ret)
270 goto err_put_path;
271
272 m = file->private_data;
273 m->poll_event = ns->event;
274
275 p = m->private;
276 p->ns = ns;
277 p->root = root;
278 p->show = show;
279 p->cached_event = ~0ULL;
280
281 return 0;
282
283 err_put_path:
284 path_put(&root);
285 err_put_ns:
286 put_mnt_ns(ns);
287 err:
288 return ret;
289}
290
291static int mounts_release(struct inode *inode, struct file *file)
292{
293 struct seq_file *m = file->private_data;
294 struct proc_mounts *p = m->private;
295 path_put(&p->root);
296 put_mnt_ns(p->ns);
297 return seq_release_private(inode, file);
298}
299
300static int mounts_open(struct inode *inode, struct file *file)
301{
302 return mounts_open_common(inode, file, show_vfsmnt);
303}
304
305static int mountinfo_open(struct inode *inode, struct file *file)
306{
307 return mounts_open_common(inode, file, show_mountinfo);
308}
309
310static int mountstats_open(struct inode *inode, struct file *file)
311{
312 return mounts_open_common(inode, file, show_vfsstat);
313}
314
315const struct file_operations proc_mounts_operations = {
316 .open = mounts_open,
317 .read = seq_read,
318 .llseek = seq_lseek,
319 .release = mounts_release,
320 .poll = mounts_poll,
321};
322
323const struct file_operations proc_mountinfo_operations = {
324 .open = mountinfo_open,
325 .read = seq_read,
326 .llseek = seq_lseek,
327 .release = mounts_release,
328 .poll = mounts_poll,
329};
330
331const struct file_operations proc_mountstats_operations = {
332 .open = mountstats_open,
333 .read = seq_read,
334 .llseek = seq_lseek,
335 .release = mounts_release,
336};
1/*
2 * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
3 *
4 * In fact, that's a piece of procfs; it's *almost* isolated from
5 * the rest of fs/proc, but has rather close relationships with
6 * fs/namespace.c, thus here instead of fs/proc
7 *
8 */
9#include <linux/mnt_namespace.h>
10#include <linux/nsproxy.h>
11#include <linux/security.h>
12#include <linux/fs_struct.h>
13#include "proc/internal.h" /* only for get_proc_task() in ->open() */
14
15#include "pnode.h"
16#include "internal.h"
17
18static unsigned mounts_poll(struct file *file, poll_table *wait)
19{
20 struct proc_mounts *p = proc_mounts(file->private_data);
21 struct mnt_namespace *ns = p->ns;
22 unsigned res = POLLIN | POLLRDNORM;
23 int event;
24
25 poll_wait(file, &p->ns->poll, wait);
26
27 event = ACCESS_ONCE(ns->event);
28 if (p->m.poll_event != event) {
29 p->m.poll_event = event;
30 res |= POLLERR | POLLPRI;
31 }
32
33 return res;
34}
35
36struct proc_fs_info {
37 int flag;
38 const char *str;
39};
40
41static int show_sb_opts(struct seq_file *m, struct super_block *sb)
42{
43 static const struct proc_fs_info fs_info[] = {
44 { MS_SYNCHRONOUS, ",sync" },
45 { MS_DIRSYNC, ",dirsync" },
46 { MS_MANDLOCK, ",mand" },
47 { 0, NULL }
48 };
49 const struct proc_fs_info *fs_infop;
50
51 for (fs_infop = fs_info; fs_infop->flag; fs_infop++) {
52 if (sb->s_flags & fs_infop->flag)
53 seq_puts(m, fs_infop->str);
54 }
55
56 return security_sb_show_options(m, sb);
57}
58
59static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
60{
61 static const struct proc_fs_info mnt_info[] = {
62 { MNT_NOSUID, ",nosuid" },
63 { MNT_NODEV, ",nodev" },
64 { MNT_NOEXEC, ",noexec" },
65 { MNT_NOATIME, ",noatime" },
66 { MNT_NODIRATIME, ",nodiratime" },
67 { MNT_RELATIME, ",relatime" },
68 { 0, NULL }
69 };
70 const struct proc_fs_info *fs_infop;
71
72 for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) {
73 if (mnt->mnt_flags & fs_infop->flag)
74 seq_puts(m, fs_infop->str);
75 }
76}
77
78static inline void mangle(struct seq_file *m, const char *s)
79{
80 seq_escape(m, s, " \t\n\\");
81}
82
83static void show_type(struct seq_file *m, struct super_block *sb)
84{
85 mangle(m, sb->s_type->name);
86 if (sb->s_subtype && sb->s_subtype[0]) {
87 seq_putc(m, '.');
88 mangle(m, sb->s_subtype);
89 }
90}
91
92static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
93{
94 struct mount *r = real_mount(mnt);
95 int err = 0;
96 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
97 struct super_block *sb = mnt_path.dentry->d_sb;
98
99 if (sb->s_op->show_devname) {
100 err = sb->s_op->show_devname(m, mnt_path.dentry);
101 if (err)
102 goto out;
103 } else {
104 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
105 }
106 seq_putc(m, ' ');
107 seq_path(m, &mnt_path, " \t\n\\");
108 seq_putc(m, ' ');
109 show_type(m, sb);
110 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
111 err = show_sb_opts(m, sb);
112 if (err)
113 goto out;
114 show_mnt_opts(m, mnt);
115 if (sb->s_op->show_options)
116 err = sb->s_op->show_options(m, mnt_path.dentry);
117 seq_puts(m, " 0 0\n");
118out:
119 return err;
120}
121
122static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
123{
124 struct proc_mounts *p = proc_mounts(m);
125 struct mount *r = real_mount(mnt);
126 struct super_block *sb = mnt->mnt_sb;
127 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
128 struct path root = p->root;
129 int err = 0;
130
131 seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
132 MAJOR(sb->s_dev), MINOR(sb->s_dev));
133 if (sb->s_op->show_path)
134 err = sb->s_op->show_path(m, mnt->mnt_root);
135 else
136 seq_dentry(m, mnt->mnt_root, " \t\n\\");
137 if (err)
138 goto out;
139 seq_putc(m, ' ');
140
141 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
142 err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
143 if (err)
144 goto out;
145
146 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
147 show_mnt_opts(m, mnt);
148
149 /* Tagged fields ("foo:X" or "bar") */
150 if (IS_MNT_SHARED(r))
151 seq_printf(m, " shared:%i", r->mnt_group_id);
152 if (IS_MNT_SLAVE(r)) {
153 int master = r->mnt_master->mnt_group_id;
154 int dom = get_dominating_id(r, &p->root);
155 seq_printf(m, " master:%i", master);
156 if (dom && dom != master)
157 seq_printf(m, " propagate_from:%i", dom);
158 }
159 if (IS_MNT_UNBINDABLE(r))
160 seq_puts(m, " unbindable");
161
162 /* Filesystem specific data */
163 seq_puts(m, " - ");
164 show_type(m, sb);
165 seq_putc(m, ' ');
166 if (sb->s_op->show_devname)
167 err = sb->s_op->show_devname(m, mnt->mnt_root);
168 else
169 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
170 if (err)
171 goto out;
172 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
173 err = show_sb_opts(m, sb);
174 if (err)
175 goto out;
176 if (sb->s_op->show_options)
177 err = sb->s_op->show_options(m, mnt->mnt_root);
178 seq_putc(m, '\n');
179out:
180 return err;
181}
182
183static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
184{
185 struct mount *r = real_mount(mnt);
186 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
187 struct super_block *sb = mnt_path.dentry->d_sb;
188 int err = 0;
189
190 /* device */
191 if (sb->s_op->show_devname) {
192 seq_puts(m, "device ");
193 err = sb->s_op->show_devname(m, mnt_path.dentry);
194 } else {
195 if (r->mnt_devname) {
196 seq_puts(m, "device ");
197 mangle(m, r->mnt_devname);
198 } else
199 seq_puts(m, "no device");
200 }
201
202 /* mount point */
203 seq_puts(m, " mounted on ");
204 seq_path(m, &mnt_path, " \t\n\\");
205 seq_putc(m, ' ');
206
207 /* file system type */
208 seq_puts(m, "with fstype ");
209 show_type(m, sb);
210
211 /* optional statistics */
212 if (sb->s_op->show_stats) {
213 seq_putc(m, ' ');
214 if (!err)
215 err = sb->s_op->show_stats(m, mnt_path.dentry);
216 }
217
218 seq_putc(m, '\n');
219 return err;
220}
221
222static int mounts_open_common(struct inode *inode, struct file *file,
223 int (*show)(struct seq_file *, struct vfsmount *))
224{
225 struct task_struct *task = get_proc_task(inode);
226 struct nsproxy *nsp;
227 struct mnt_namespace *ns = NULL;
228 struct path root;
229 struct proc_mounts *p;
230 int ret = -EINVAL;
231
232 if (!task)
233 goto err;
234
235 rcu_read_lock();
236 nsp = task_nsproxy(task);
237 if (!nsp || !nsp->mnt_ns) {
238 rcu_read_unlock();
239 put_task_struct(task);
240 goto err;
241 }
242 ns = nsp->mnt_ns;
243 get_mnt_ns(ns);
244 rcu_read_unlock();
245 task_lock(task);
246 if (!task->fs) {
247 task_unlock(task);
248 put_task_struct(task);
249 ret = -ENOENT;
250 goto err_put_ns;
251 }
252 get_fs_root(task->fs, &root);
253 task_unlock(task);
254 put_task_struct(task);
255
256 ret = -ENOMEM;
257 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
258 if (!p)
259 goto err_put_path;
260
261 file->private_data = &p->m;
262 ret = seq_open(file, &mounts_op);
263 if (ret)
264 goto err_free;
265
266 p->ns = ns;
267 p->root = root;
268 p->m.poll_event = ns->event;
269 p->show = show;
270 p->cached_event = ~0ULL;
271
272 return 0;
273
274 err_free:
275 kfree(p);
276 err_put_path:
277 path_put(&root);
278 err_put_ns:
279 put_mnt_ns(ns);
280 err:
281 return ret;
282}
283
284static int mounts_release(struct inode *inode, struct file *file)
285{
286 struct proc_mounts *p = proc_mounts(file->private_data);
287 path_put(&p->root);
288 put_mnt_ns(p->ns);
289 return seq_release(inode, file);
290}
291
292static int mounts_open(struct inode *inode, struct file *file)
293{
294 return mounts_open_common(inode, file, show_vfsmnt);
295}
296
297static int mountinfo_open(struct inode *inode, struct file *file)
298{
299 return mounts_open_common(inode, file, show_mountinfo);
300}
301
302static int mountstats_open(struct inode *inode, struct file *file)
303{
304 return mounts_open_common(inode, file, show_vfsstat);
305}
306
307const struct file_operations proc_mounts_operations = {
308 .open = mounts_open,
309 .read = seq_read,
310 .llseek = seq_lseek,
311 .release = mounts_release,
312 .poll = mounts_poll,
313};
314
315const struct file_operations proc_mountinfo_operations = {
316 .open = mountinfo_open,
317 .read = seq_read,
318 .llseek = seq_lseek,
319 .release = mounts_release,
320 .poll = mounts_poll,
321};
322
323const struct file_operations proc_mountstats_operations = {
324 .open = mountstats_open,
325 .read = seq_read,
326 .llseek = seq_lseek,
327 .release = mounts_release,
328};