blk-mq: don't count completed flush data request as inflight in case of quiesce
[linux-block.git] / fs / proc_namespace.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
0226f492
AV
2/*
3 * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
4 *
5 * In fact, that's a piece of procfs; it's *almost* isolated from
6 * the rest of fs/proc, but has rather close relationships with
7 * fs/namespace.c, thus here instead of fs/proc
8 *
9 */
10#include <linux/mnt_namespace.h>
11#include <linux/nsproxy.h>
12#include <linux/security.h>
13#include <linux/fs_struct.h>
f719ff9b
IM
14#include <linux/sched/task.h>
15
0226f492
AV
16#include "proc/internal.h" /* only for get_proc_task() in ->open() */
17
18#include "pnode.h"
19#include "internal.h"
20
076ccb76 21static __poll_t mounts_poll(struct file *file, poll_table *wait)
0226f492 22{
ede1bf0d
YD
23 struct seq_file *m = file->private_data;
24 struct proc_mounts *p = m->private;
0226f492 25 struct mnt_namespace *ns = p->ns;
a9a08845 26 __poll_t res = EPOLLIN | EPOLLRDNORM;
aab407fc 27 int event;
0226f492
AV
28
29 poll_wait(file, &p->ns->poll, wait);
30
6aa7de05 31 event = READ_ONCE(ns->event);
ede1bf0d
YD
32 if (m->poll_event != event) {
33 m->poll_event = event;
a9a08845 34 res |= EPOLLERR | EPOLLPRI;
0226f492 35 }
0226f492
AV
36
37 return res;
38}
39
1e88c420 40struct proc_fs_opts {
0226f492
AV
41 int flag;
42 const char *str;
43};
44
45static int show_sb_opts(struct seq_file *m, struct super_block *sb)
46{
1e88c420 47 static const struct proc_fs_opts fs_opts[] = {
1751e8a6
LT
48 { SB_SYNCHRONOUS, ",sync" },
49 { SB_DIRSYNC, ",dirsync" },
50 { SB_MANDLOCK, ",mand" },
51 { SB_LAZYTIME, ",lazytime" },
0226f492
AV
52 { 0, NULL }
53 };
1e88c420 54 const struct proc_fs_opts *fs_infop;
0226f492 55
1e88c420 56 for (fs_infop = fs_opts; fs_infop->flag; fs_infop++) {
0226f492
AV
57 if (sb->s_flags & fs_infop->flag)
58 seq_puts(m, fs_infop->str);
59 }
60
61 return security_sb_show_options(m, sb);
62}
63
64static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
65{
1e88c420 66 static const struct proc_fs_opts mnt_opts[] = {
0226f492
AV
67 { MNT_NOSUID, ",nosuid" },
68 { MNT_NODEV, ",nodev" },
69 { MNT_NOEXEC, ",noexec" },
70 { MNT_NOATIME, ",noatime" },
71 { MNT_NODIRATIME, ",nodiratime" },
72 { MNT_RELATIME, ",relatime" },
dab741e0 73 { MNT_NOSYMFOLLOW, ",nosymfollow" },
0226f492
AV
74 { 0, NULL }
75 };
1e88c420 76 const struct proc_fs_opts *fs_infop;
0226f492 77
1e88c420 78 for (fs_infop = mnt_opts; fs_infop->flag; fs_infop++) {
0226f492
AV
79 if (mnt->mnt_flags & fs_infop->flag)
80 seq_puts(m, fs_infop->str);
81 }
9caccd41 82
bb49e9e7 83 if (is_idmapped_mnt(mnt))
9caccd41 84 seq_puts(m, ",idmapped");
0226f492
AV
85}
86
87static inline void mangle(struct seq_file *m, const char *s)
88{
ed5fce76 89 seq_escape(m, s, " \t\n\\#");
0226f492
AV
90}
91
92static void show_type(struct seq_file *m, struct super_block *sb)
93{
94 mangle(m, sb->s_type->name);
c7eb6869 95 if (sb->s_subtype) {
0226f492
AV
96 seq_putc(m, '.');
97 mangle(m, sb->s_subtype);
98 }
99}
100
101static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
102{
ede1bf0d 103 struct proc_mounts *p = m->private;
0226f492 104 struct mount *r = real_mount(mnt);
0226f492 105 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
d861c630 106 struct super_block *sb = mnt_path.dentry->d_sb;
5d9f3c7b 107 int err;
0226f492 108
d861c630
AV
109 if (sb->s_op->show_devname) {
110 err = sb->s_op->show_devname(m, mnt_path.dentry);
0226f492
AV
111 if (err)
112 goto out;
113 } else {
114 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
115 }
116 seq_putc(m, ' ');
9d4d6574
DL
117 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
118 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
119 if (err)
120 goto out;
0226f492 121 seq_putc(m, ' ');
d861c630 122 show_type(m, sb);
0226f492 123 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
d861c630 124 err = show_sb_opts(m, sb);
0226f492
AV
125 if (err)
126 goto out;
127 show_mnt_opts(m, mnt);
d861c630 128 if (sb->s_op->show_options)
34c80b1d 129 err = sb->s_op->show_options(m, mnt_path.dentry);
0226f492
AV
130 seq_puts(m, " 0 0\n");
131out:
132 return err;
133}
134
135static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
136{
ede1bf0d 137 struct proc_mounts *p = m->private;
0226f492
AV
138 struct mount *r = real_mount(mnt);
139 struct super_block *sb = mnt->mnt_sb;
140 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
6ce4bca0 141 int err;
0226f492
AV
142
143 seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
144 MAJOR(sb->s_dev), MINOR(sb->s_dev));
6ce4bca0 145 if (sb->s_op->show_path) {
a6322de6 146 err = sb->s_op->show_path(m, mnt->mnt_root);
6ce4bca0
DL
147 if (err)
148 goto out;
149 } else {
0226f492 150 seq_dentry(m, mnt->mnt_root, " \t\n\\");
6ce4bca0 151 }
0226f492
AV
152 seq_putc(m, ' ');
153
154 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
9ad4dc4f 155 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
0226f492
AV
156 if (err)
157 goto out;
158
159 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
160 show_mnt_opts(m, mnt);
161
162 /* Tagged fields ("foo:X" or "bar") */
163 if (IS_MNT_SHARED(r))
164 seq_printf(m, " shared:%i", r->mnt_group_id);
165 if (IS_MNT_SLAVE(r)) {
166 int master = r->mnt_master->mnt_group_id;
167 int dom = get_dominating_id(r, &p->root);
168 seq_printf(m, " master:%i", master);
169 if (dom && dom != master)
170 seq_printf(m, " propagate_from:%i", dom);
171 }
172 if (IS_MNT_UNBINDABLE(r))
173 seq_puts(m, " unbindable");
174
175 /* Filesystem specific data */
176 seq_puts(m, " - ");
177 show_type(m, sb);
178 seq_putc(m, ' ');
6ce4bca0 179 if (sb->s_op->show_devname) {
d861c630 180 err = sb->s_op->show_devname(m, mnt->mnt_root);
6ce4bca0
DL
181 if (err)
182 goto out;
183 } else {
0226f492 184 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
6ce4bca0 185 }
bc98a42c 186 seq_puts(m, sb_rdonly(sb) ? " ro" : " rw");
0226f492
AV
187 err = show_sb_opts(m, sb);
188 if (err)
189 goto out;
190 if (sb->s_op->show_options)
34c80b1d 191 err = sb->s_op->show_options(m, mnt->mnt_root);
0226f492
AV
192 seq_putc(m, '\n');
193out:
194 return err;
195}
196
197static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
198{
ede1bf0d 199 struct proc_mounts *p = m->private;
0226f492
AV
200 struct mount *r = real_mount(mnt);
201 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
64132379 202 struct super_block *sb = mnt_path.dentry->d_sb;
b896fb35 203 int err;
0226f492
AV
204
205 /* device */
64132379 206 if (sb->s_op->show_devname) {
0226f492 207 seq_puts(m, "device ");
d861c630 208 err = sb->s_op->show_devname(m, mnt_path.dentry);
5f8d498d
DL
209 if (err)
210 goto out;
0226f492
AV
211 } else {
212 if (r->mnt_devname) {
213 seq_puts(m, "device ");
214 mangle(m, r->mnt_devname);
215 } else
216 seq_puts(m, "no device");
217 }
218
219 /* mount point */
220 seq_puts(m, " mounted on ");
9d4d6574
DL
221 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
222 err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\");
223 if (err)
224 goto out;
0226f492
AV
225 seq_putc(m, ' ');
226
227 /* file system type */
228 seq_puts(m, "with fstype ");
64132379 229 show_type(m, sb);
0226f492
AV
230
231 /* optional statistics */
64132379 232 if (sb->s_op->show_stats) {
0226f492 233 seq_putc(m, ' ');
b896fb35 234 err = sb->s_op->show_stats(m, mnt_path.dentry);
0226f492
AV
235 }
236
237 seq_putc(m, '\n');
9d4d6574 238out:
0226f492
AV
239 return err;
240}
241
242static int mounts_open_common(struct inode *inode, struct file *file,
243 int (*show)(struct seq_file *, struct vfsmount *))
244{
245 struct task_struct *task = get_proc_task(inode);
246 struct nsproxy *nsp;
247 struct mnt_namespace *ns = NULL;
248 struct path root;
249 struct proc_mounts *p;
ede1bf0d 250 struct seq_file *m;
0226f492
AV
251 int ret = -EINVAL;
252
253 if (!task)
254 goto err;
255
728dba3a
EB
256 task_lock(task);
257 nsp = task->nsproxy;
3d93116c 258 if (!nsp || !nsp->mnt_ns) {
728dba3a 259 task_unlock(task);
0226f492
AV
260 put_task_struct(task);
261 goto err;
262 }
263 ns = nsp->mnt_ns;
0226f492 264 get_mnt_ns(ns);
0226f492
AV
265 if (!task->fs) {
266 task_unlock(task);
267 put_task_struct(task);
268 ret = -ENOENT;
269 goto err_put_ns;
270 }
271 get_fs_root(task->fs, &root);
272 task_unlock(task);
273 put_task_struct(task);
274
ede1bf0d
YD
275 ret = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts));
276 if (ret)
0226f492
AV
277 goto err_put_path;
278
ede1bf0d
YD
279 m = file->private_data;
280 m->poll_event = ns->event;
0226f492 281
ede1bf0d 282 p = m->private;
0226f492
AV
283 p->ns = ns;
284 p->root = root;
0226f492 285 p->show = show;
9f6c61f9
MS
286 INIT_LIST_HEAD(&p->cursor.mnt_list);
287 p->cursor.mnt.mnt_flags = MNT_CURSOR;
0226f492
AV
288
289 return 0;
290
0226f492
AV
291 err_put_path:
292 path_put(&root);
293 err_put_ns:
294 put_mnt_ns(ns);
295 err:
296 return ret;
297}
298
299static int mounts_release(struct inode *inode, struct file *file)
300{
ede1bf0d
YD
301 struct seq_file *m = file->private_data;
302 struct proc_mounts *p = m->private;
0226f492 303 path_put(&p->root);
9f6c61f9 304 mnt_cursor_del(p->ns, &p->cursor);
0226f492 305 put_mnt_ns(p->ns);
ede1bf0d 306 return seq_release_private(inode, file);
0226f492
AV
307}
308
309static int mounts_open(struct inode *inode, struct file *file)
310{
311 return mounts_open_common(inode, file, show_vfsmnt);
312}
313
314static int mountinfo_open(struct inode *inode, struct file *file)
315{
316 return mounts_open_common(inode, file, show_mountinfo);
317}
318
319static int mountstats_open(struct inode *inode, struct file *file)
320{
321 return mounts_open_common(inode, file, show_vfsstat);
322}
323
324const struct file_operations proc_mounts_operations = {
325 .open = mounts_open,
14e3e989 326 .read_iter = seq_read_iter,
b0072734 327 .splice_read = copy_splice_read,
0226f492
AV
328 .llseek = seq_lseek,
329 .release = mounts_release,
330 .poll = mounts_poll,
331};
332
333const struct file_operations proc_mountinfo_operations = {
334 .open = mountinfo_open,
14e3e989 335 .read_iter = seq_read_iter,
b0072734 336 .splice_read = copy_splice_read,
0226f492
AV
337 .llseek = seq_lseek,
338 .release = mounts_release,
339 .poll = mounts_poll,
340};
341
342const struct file_operations proc_mountstats_operations = {
343 .open = mountstats_open,
14e3e989 344 .read_iter = seq_read_iter,
b0072734 345 .splice_read = copy_splice_read,
0226f492
AV
346 .llseek = seq_lseek,
347 .release = mounts_release,
348};