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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338// SPDX-License-Identifier: GPL-2.0/* * 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 <linux/sched/task.h>
#include "proc/internal.h" /* only for get_proc_task() in ->open() */
#include "pnode.h"#include "internal.h"
static __poll_t mounts_poll(struct file *file, poll_table *wait){ struct seq_file *m = file->private_data; struct proc_mounts *p = m->private; struct mnt_namespace *ns = p->ns; __poll_t res = EPOLLIN | EPOLLRDNORM; int event;
poll_wait(file, &p->ns->poll, wait);
event = READ_ONCE(ns->event); if (m->poll_event != event) { m->poll_event = event; res |= EPOLLERR | EPOLLPRI; }
return res;}
struct proc_fs_opts { int flag; const char *str;};
static int show_sb_opts(struct seq_file *m, struct super_block *sb){ static const struct proc_fs_opts fs_opts[] = { { SB_SYNCHRONOUS, ",sync" }, { SB_DIRSYNC, ",dirsync" }, { SB_MANDLOCK, ",mand" }, { SB_LAZYTIME, ",lazytime" }, { 0, NULL } }; const struct proc_fs_opts *fs_infop;
for (fs_infop = fs_opts; 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_vfsmnt_opts(struct seq_file *m, struct vfsmount *mnt){ static const struct proc_fs_opts mnt_opts[] = { { MNT_NOSUID, ",nosuid" }, { MNT_NODEV, ",nodev" }, { MNT_NOEXEC, ",noexec" }, { MNT_NOATIME, ",noatime" }, { MNT_NODIRATIME, ",nodiratime" }, { MNT_RELATIME, ",relatime" }, { MNT_NOSYMFOLLOW, ",nosymfollow" }, { 0, NULL } }; const struct proc_fs_opts *fs_infop;
for (fs_infop = mnt_opts; fs_infop->flag; fs_infop++) { if (mnt->mnt_flags & fs_infop->flag) seq_puts(m, fs_infop->str); }
if (is_idmapped_mnt(mnt)) seq_puts(m, ",idmapped");}
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) { seq_putc(m, '.'); mangle(m, sb->s_subtype); }}
static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt){ struct proc_mounts *p = m->private; 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;
if (sb->s_op->show_devname) { err = sb->s_op->show_devname(m, mnt_path.dentry); if (err) goto out; } else { mangle(m, r->mnt_devname); } seq_putc(m, ' '); /* mountpoints outside of chroot jail will give SEQ_SKIP on this */ err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\"); if (err) goto out; seq_putc(m, ' '); show_type(m, sb); seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw"); err = show_sb_opts(m, sb); if (err) goto out; show_vfsmnt_opts(m, mnt); if (sb->s_op->show_options) err = sb->s_op->show_options(m, mnt_path.dentry); 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 }; int err;
seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id, MAJOR(sb->s_dev), MINOR(sb->s_dev)); err = show_path(m, mnt->mnt_root); 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, &p->root, " \t\n\\"); if (err) goto out;
seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw"); show_vfsmnt_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->mnt_root); if (err) goto out; } else { mangle(m, r->mnt_devname); } seq_puts(m, sb_rdonly(sb) ? " 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->mnt_root); seq_putc(m, '\n');out: return err;}
static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt){ struct proc_mounts *p = m->private; 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;
/* device */ seq_puts(m, "device "); if (sb->s_op->show_devname) { err = sb->s_op->show_devname(m, mnt_path.dentry); if (err) goto out; } else { mangle(m, r->mnt_devname); }
/* mount point */ seq_puts(m, " mounted on "); /* mountpoints outside of chroot jail will give SEQ_SKIP on this */ err = seq_path_root(m, &mnt_path, &p->root, " \t\n\\"); if (err) goto out; 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, ' '); err = sb->s_op->show_stats(m, mnt_path.dentry); }
seq_putc(m, '\n');out: 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; struct seq_file *m; int ret = -EINVAL;
if (!task) goto err;
task_lock(task); nsp = task->nsproxy; if (!nsp || !nsp->mnt_ns) { task_unlock(task); put_task_struct(task); goto err; } ns = nsp->mnt_ns; get_mnt_ns(ns); 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 = seq_open_private(file, &mounts_op, sizeof(struct proc_mounts)); if (ret) goto err_put_path;
m = file->private_data; m->poll_event = ns->event;
p = m->private; p->ns = ns; p->root = root; p->show = show;
return 0;
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 seq_file *m = file->private_data; struct proc_mounts *p = m->private; path_put(&p->root); put_mnt_ns(p->ns); return seq_release_private(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_iter = seq_read_iter, .splice_read = copy_splice_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll,};
const struct file_operations proc_mountinfo_operations = { .open = mountinfo_open, .read_iter = seq_read_iter, .splice_read = copy_splice_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll,};
const struct file_operations proc_mountstats_operations = { .open = mountstats_open, .read_iter = seq_read_iter, .splice_read = copy_splice_read, .llseek = seq_lseek, .release = mounts_release,};