2 * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats}
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
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() */
18 static unsigned mounts_poll(struct file *file, poll_table *wait)
20 struct proc_mounts *p = proc_mounts(file->private_data);
21 struct mnt_namespace *ns = p->ns;
22 unsigned res = POLLIN | POLLRDNORM;
24 poll_wait(file, &p->ns->poll, wait);
26 br_read_lock(&vfsmount_lock);
27 if (p->m.poll_event != ns->event) {
28 p->m.poll_event = ns->event;
29 res |= POLLERR | POLLPRI;
31 br_read_unlock(&vfsmount_lock);
41 static int show_sb_opts(struct seq_file *m, struct super_block *sb)
43 static const struct proc_fs_info fs_info[] = {
44 { MS_SYNCHRONOUS, ",sync" },
45 { MS_DIRSYNC, ",dirsync" },
46 { MS_MANDLOCK, ",mand" },
49 const struct proc_fs_info *fs_infop;
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);
56 return security_sb_show_options(m, sb);
59 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
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" },
70 const struct proc_fs_info *fs_infop;
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);
78 static inline void mangle(struct seq_file *m, const char *s)
80 seq_escape(m, s, " \t\n\\");
83 static void show_type(struct seq_file *m, struct super_block *sb)
85 mangle(m, sb->s_type->name);
86 if (sb->s_subtype && sb->s_subtype[0]) {
88 mangle(m, sb->s_subtype);
92 static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
94 struct mount *r = real_mount(mnt);
96 struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
97 struct super_block *sb = mnt_path.dentry->d_sb;
99 if (sb->s_op->show_devname) {
100 err = sb->s_op->show_devname(m, mnt_path.dentry);
104 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
107 seq_path(m, &mnt_path, " \t\n\\");
110 seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
111 err = show_sb_opts(m, sb);
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");
122 static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
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;
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);
136 seq_dentry(m, mnt->mnt_root, " \t\n\\");
141 /* mountpoints outside of chroot jail will give SEQ_SKIP on this */
142 err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
146 seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
147 show_mnt_opts(m, mnt);
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);
159 if (IS_MNT_UNBINDABLE(r))
160 seq_puts(m, " unbindable");
162 /* Filesystem specific data */
166 if (sb->s_op->show_devname)
167 err = sb->s_op->show_devname(m, mnt->mnt_root);
169 mangle(m, r->mnt_devname ? r->mnt_devname : "none");
172 seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
173 err = show_sb_opts(m, sb);
176 if (sb->s_op->show_options)
177 err = sb->s_op->show_options(m, mnt->mnt_root);
183 static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
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;
191 if (sb->s_op->show_devname) {
192 seq_puts(m, "device ");
193 err = sb->s_op->show_devname(m, mnt_path.dentry);
195 if (r->mnt_devname) {
196 seq_puts(m, "device ");
197 mangle(m, r->mnt_devname);
199 seq_puts(m, "no device");
203 seq_puts(m, " mounted on ");
204 seq_path(m, &mnt_path, " \t\n\\");
207 /* file system type */
208 seq_puts(m, "with fstype ");
211 /* optional statistics */
212 if (sb->s_op->show_stats) {
215 err = sb->s_op->show_stats(m, mnt_path.dentry);
222 static int mounts_open_common(struct inode *inode, struct file *file,
223 int (*show)(struct seq_file *, struct vfsmount *))
225 struct task_struct *task = get_proc_task(inode);
227 struct mnt_namespace *ns = NULL;
229 struct proc_mounts *p;
236 nsp = task_nsproxy(task);
239 put_task_struct(task);
245 put_task_struct(task);
253 put_task_struct(task);
257 get_fs_root(task->fs, &root);
259 put_task_struct(task);
262 p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
266 file->private_data = &p->m;
267 ret = seq_open(file, &mounts_op);
273 p->m.poll_event = ns->event;
288 static int mounts_release(struct inode *inode, struct file *file)
290 struct proc_mounts *p = proc_mounts(file->private_data);
293 return seq_release(inode, file);
296 static int mounts_open(struct inode *inode, struct file *file)
298 return mounts_open_common(inode, file, show_vfsmnt);
301 static int mountinfo_open(struct inode *inode, struct file *file)
303 return mounts_open_common(inode, file, show_mountinfo);
306 static int mountstats_open(struct inode *inode, struct file *file)
308 return mounts_open_common(inode, file, show_vfsstat);
311 const struct file_operations proc_mounts_operations = {
315 .release = mounts_release,
319 const struct file_operations proc_mountinfo_operations = {
320 .open = mountinfo_open,
323 .release = mounts_release,
327 const struct file_operations proc_mountstats_operations = {
328 .open = mountstats_open,
331 .release = mounts_release,