| /* |
| * fs/proc_namespace.c - handling of /proc/<pid>/{mounts,mountinfo,mountstats} |
| * |
| * In fact, that's a piece of procfs; it's *almost* isolated from |
| * the rest of fs/proc, but has rather close relationships with |
| * fs/namespace.c, thus here instead of fs/proc |
| * |
| */ |
| #include <linux/mnt_namespace.h> |
| #include <linux/nsproxy.h> |
| #include <linux/security.h> |
| #include <linux/fs_struct.h> |
| #include "proc/internal.h" /* only for get_proc_task() in ->open() */ |
| |
| #include "pnode.h" |
| #include "internal.h" |
| |
| static unsigned mounts_poll(struct file *file, poll_table *wait) |
| { |
| struct proc_mounts *p = file->private_data; |
| struct mnt_namespace *ns = p->ns; |
| unsigned res = POLLIN | POLLRDNORM; |
| |
| poll_wait(file, &p->ns->poll, wait); |
| |
| br_read_lock(vfsmount_lock); |
| if (p->m.poll_event != ns->event) { |
| p->m.poll_event = ns->event; |
| res |= POLLERR | POLLPRI; |
| } |
| br_read_unlock(vfsmount_lock); |
| |
| return res; |
| } |
| |
| struct proc_fs_info { |
| int flag; |
| const char *str; |
| }; |
| |
| static int show_sb_opts(struct seq_file *m, struct super_block *sb) |
| { |
| static const struct proc_fs_info fs_info[] = { |
| { MS_SYNCHRONOUS, ",sync" }, |
| { MS_DIRSYNC, ",dirsync" }, |
| { MS_MANDLOCK, ",mand" }, |
| { 0, NULL } |
| }; |
| const struct proc_fs_info *fs_infop; |
| |
| for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { |
| if (sb->s_flags & fs_infop->flag) |
| seq_puts(m, fs_infop->str); |
| } |
| |
| return security_sb_show_options(m, sb); |
| } |
| |
| static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt) |
| { |
| static const struct proc_fs_info mnt_info[] = { |
| { MNT_NOSUID, ",nosuid" }, |
| { MNT_NODEV, ",nodev" }, |
| { MNT_NOEXEC, ",noexec" }, |
| { MNT_NOATIME, ",noatime" }, |
| { MNT_NODIRATIME, ",nodiratime" }, |
| { MNT_RELATIME, ",relatime" }, |
| { 0, NULL } |
| }; |
| const struct proc_fs_info *fs_infop; |
| |
| for (fs_infop = mnt_info; fs_infop->flag; fs_infop++) { |
| if (mnt->mnt_flags & fs_infop->flag) |
| seq_puts(m, fs_infop->str); |
| } |
| } |
| |
| static inline void mangle(struct seq_file *m, const char *s) |
| { |
| seq_escape(m, s, " \t\n\\"); |
| } |
| |
| static void show_type(struct seq_file *m, struct super_block *sb) |
| { |
| mangle(m, sb->s_type->name); |
| if (sb->s_subtype && sb->s_subtype[0]) { |
| seq_putc(m, '.'); |
| mangle(m, sb->s_subtype); |
| } |
| } |
| |
| static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct mount *r = real_mount(mnt); |
| int err = 0; |
| struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt }; |
| |
| if (mnt->mnt_sb->s_op->show_devname) { |
| err = mnt->mnt_sb->s_op->show_devname(m, mnt); |
| if (err) |
| goto out; |
| } else { |
| mangle(m, r->mnt_devname ? r->mnt_devname : "none"); |
| } |
| seq_putc(m, ' '); |
| seq_path(m, &mnt_path, " \t\n\\"); |
| seq_putc(m, ' '); |
| show_type(m, mnt->mnt_sb); |
| seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw"); |
| err = show_sb_opts(m, mnt->mnt_sb); |
| if (err) |
| goto out; |
| show_mnt_opts(m, mnt); |
| if (mnt->mnt_sb->s_op->show_options) |
| err = mnt->mnt_sb->s_op->show_options(m, mnt); |
| seq_puts(m, " 0 0\n"); |
| out: |
| return err; |
| } |
| |
| static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct proc_mounts *p = m->private; |
| struct mount *r = real_mount(mnt); |
| struct super_block *sb = mnt->mnt_sb; |
| struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt }; |
| struct path root = p->root; |
| int err = 0; |
| |
| seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id, |
| MAJOR(sb->s_dev), MINOR(sb->s_dev)); |
| if (sb->s_op->show_path) |
| err = sb->s_op->show_path(m, mnt); |
| else |
| seq_dentry(m, mnt->mnt_root, " \t\n\\"); |
| if (err) |
| goto out; |
| seq_putc(m, ' '); |
| |
| /* mountpoints outside of chroot jail will give SEQ_SKIP on this */ |
| err = seq_path_root(m, &mnt_path, &root, " \t\n\\"); |
| if (err) |
| goto out; |
| |
| seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw"); |
| show_mnt_opts(m, mnt); |
| |
| /* Tagged fields ("foo:X" or "bar") */ |
| if (IS_MNT_SHARED(r)) |
| seq_printf(m, " shared:%i", r->mnt_group_id); |
| if (IS_MNT_SLAVE(r)) { |
| int master = r->mnt_master->mnt_group_id; |
| int dom = get_dominating_id(r, &p->root); |
| seq_printf(m, " master:%i", master); |
| if (dom && dom != master) |
| seq_printf(m, " propagate_from:%i", dom); |
| } |
| if (IS_MNT_UNBINDABLE(r)) |
| seq_puts(m, " unbindable"); |
| |
| /* Filesystem specific data */ |
| seq_puts(m, " - "); |
| show_type(m, sb); |
| seq_putc(m, ' '); |
| if (sb->s_op->show_devname) |
| err = sb->s_op->show_devname(m, mnt); |
| else |
| mangle(m, r->mnt_devname ? r->mnt_devname : "none"); |
| if (err) |
| goto out; |
| seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw"); |
| err = show_sb_opts(m, sb); |
| if (err) |
| goto out; |
| if (sb->s_op->show_options) |
| err = sb->s_op->show_options(m, mnt); |
| seq_putc(m, '\n'); |
| out: |
| return err; |
| } |
| |
| static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct mount *r = real_mount(mnt); |
| struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt }; |
| struct super_block *sb = mnt_path.dentry->d_sb; |
| int err = 0; |
| |
| /* device */ |
| if (sb->s_op->show_devname) { |
| seq_puts(m, "device "); |
| err = sb->s_op->show_devname(m, mnt); |
| } else { |
| if (r->mnt_devname) { |
| seq_puts(m, "device "); |
| mangle(m, r->mnt_devname); |
| } else |
| seq_puts(m, "no device"); |
| } |
| |
| /* mount point */ |
| seq_puts(m, " mounted on "); |
| seq_path(m, &mnt_path, " \t\n\\"); |
| seq_putc(m, ' '); |
| |
| /* file system type */ |
| seq_puts(m, "with fstype "); |
| show_type(m, sb); |
| |
| /* optional statistics */ |
| if (sb->s_op->show_stats) { |
| seq_putc(m, ' '); |
| if (!err) |
| err = sb->s_op->show_stats(m, mnt_path.dentry); |
| } |
| |
| seq_putc(m, '\n'); |
| return err; |
| } |
| |
| static int mounts_open_common(struct inode *inode, struct file *file, |
| int (*show)(struct seq_file *, struct vfsmount *)) |
| { |
| struct task_struct *task = get_proc_task(inode); |
| struct nsproxy *nsp; |
| struct mnt_namespace *ns = NULL; |
| struct path root; |
| struct proc_mounts *p; |
| int ret = -EINVAL; |
| |
| if (!task) |
| goto err; |
| |
| rcu_read_lock(); |
| nsp = task_nsproxy(task); |
| if (!nsp) { |
| rcu_read_unlock(); |
| put_task_struct(task); |
| goto err; |
| } |
| ns = nsp->mnt_ns; |
| if (!ns) { |
| rcu_read_unlock(); |
| put_task_struct(task); |
| goto err; |
| } |
| get_mnt_ns(ns); |
| rcu_read_unlock(); |
| task_lock(task); |
| if (!task->fs) { |
| task_unlock(task); |
| put_task_struct(task); |
| ret = -ENOENT; |
| goto err_put_ns; |
| } |
| get_fs_root(task->fs, &root); |
| task_unlock(task); |
| put_task_struct(task); |
| |
| ret = -ENOMEM; |
| p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL); |
| if (!p) |
| goto err_put_path; |
| |
| file->private_data = &p->m; |
| ret = seq_open(file, &mounts_op); |
| if (ret) |
| goto err_free; |
| |
| p->m.private = p; |
| p->ns = ns; |
| p->root = root; |
| p->m.poll_event = ns->event; |
| p->show = show; |
| |
| return 0; |
| |
| err_free: |
| kfree(p); |
| err_put_path: |
| path_put(&root); |
| err_put_ns: |
| put_mnt_ns(ns); |
| err: |
| return ret; |
| } |
| |
| static int mounts_release(struct inode *inode, struct file *file) |
| { |
| struct proc_mounts *p = file->private_data; |
| path_put(&p->root); |
| put_mnt_ns(p->ns); |
| return seq_release(inode, file); |
| } |
| |
| static int mounts_open(struct inode *inode, struct file *file) |
| { |
| return mounts_open_common(inode, file, show_vfsmnt); |
| } |
| |
| static int mountinfo_open(struct inode *inode, struct file *file) |
| { |
| return mounts_open_common(inode, file, show_mountinfo); |
| } |
| |
| static int mountstats_open(struct inode *inode, struct file *file) |
| { |
| return mounts_open_common(inode, file, show_vfsstat); |
| } |
| |
| const struct file_operations proc_mounts_operations = { |
| .open = mounts_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = mounts_release, |
| .poll = mounts_poll, |
| }; |
| |
| const struct file_operations proc_mountinfo_operations = { |
| .open = mountinfo_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = mounts_release, |
| .poll = mounts_poll, |
| }; |
| |
| const struct file_operations proc_mountstats_operations = { |
| .open = mountstats_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = mounts_release, |
| }; |