vfs: take /proc/*/mounts and friends to fs/proc_namespace.c

rationale: that stuff is far tighter bound to fs/namespace.c than to
the guts of procfs proper.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 364 insertions, 325 deletions

diff --git a/fs/Makefile b/fs/Makefile
index d2c3353d5477..310cfc4e69d3 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -19,6 +19,8 @@ else
 obj-y +=        no-block.o
 endif
 
+obj-$(CONFIG_PROC_FS) += proc_namespace.o
+
 obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
 obj-y                           += notify/
 obj-$(CONFIG_EPOLL)             += eventpoll.o
diff --git a/fs/mount.h b/fs/mount.h
index e094c863c8af..c6e99e03350a 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -1,4 +1,14 @@
 #include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/poll.h>
+
+struct mnt_namespace {
+        atomic_t                count;
+        struct vfsmount *       root;
+        struct list_head        list;
+        wait_queue_head_t poll;
+        int event;
+};
 
 struct mnt_pcp {
         int mnt_count;
@@ -49,3 +59,17 @@ static inline int mnt_has_parent(struct mount *mnt)
 }
 
 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
+
+static inline void get_mnt_ns(struct mnt_namespace *ns)
+{
+        atomic_inc(&ns->count);
+}
+
+struct proc_mounts {
+        struct seq_file m; /* must be the first element */
+        struct mnt_namespace *ns;
+        struct path root;
+        int (*show)(struct seq_file *, struct vfsmount *);
+};
+
+extern const struct seq_operations mounts_op;
diff --git a/fs/namespace.c b/fs/namespace.c
index cd6389387d1f..21a8261256dd 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -898,10 +898,10 @@ void replace_mount_options(struct super_block *sb, char *options)
 EXPORT_SYMBOL(replace_mount_options);
 
 #ifdef CONFIG_PROC_FS
-/* iterator */
+/* iterator; we want it to have access to namespace_sem, thus here... */
 static void *m_start(struct seq_file *m, loff_t *pos)
 {
-        struct proc_mounts *p = m->private;
+        struct proc_mounts *p = container_of(m, struct proc_mounts, m);
 
         down_read(&namespace_sem);
         return seq_list_start(&p->ns->list, *pos);
@@ -909,7 +909,7 @@ static void *m_start(struct seq_file *m, loff_t *pos)
 
 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        struct proc_mounts *p = m->private;
+        struct proc_mounts *p = container_of(m, struct proc_mounts, m);
 
         return seq_list_next(v, &p->ns->list, pos);
 }
@@ -919,222 +919,18 @@ static void m_stop(struct seq_file *m, void *v)
         up_read(&namespace_sem);
 }
 
-int mnt_had_events(struct proc_mounts *p)
-{
-        struct mnt_namespace *ns = p->ns;
-        int res = 0;
-
-        br_read_lock(vfsmount_lock);
-        if (p->m.poll_event != ns->event) {
-                p->m.poll_event = ns->event;
-                res = 1;
-        }
-        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 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, void *v)
+static int m_show(struct seq_file *m, void *v)
 {
+        struct proc_mounts *p = container_of(m, struct proc_mounts, m);
         struct mount *r = list_entry(v, struct mount, mnt_list);
-        struct vfsmount *mnt = &r->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;
+        return p->show(m, &r->mnt);
 }
 
 const struct seq_operations mounts_op = {
         .start  = m_start,
         .next   = m_next,
         .stop   = m_stop,
-        .show   = show_vfsmnt
-};
-
-static int show_mountinfo(struct seq_file *m, void *v)
-{
-        struct proc_mounts *p = m->private;
-        struct mount *r = list_entry(v, struct mount, mnt_list);
-        struct vfsmount *mnt = &r->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;
-}
-
-const struct seq_operations mountinfo_op = {
-        .start  = m_start,
-        .next   = m_next,
-        .stop   = m_stop,
-        .show   = show_mountinfo,
-};
-
-static int show_vfsstat(struct seq_file *m, void *v)
-{
-        struct mount *r = list_entry(v, struct mount, mnt_list);
-        struct vfsmount *mnt = &r->mnt;
-        struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
-        int err = 0;
-
-        /* device */
-        if (mnt->mnt_sb->s_op->show_devname) {
-                seq_puts(m, "device ");
-                err = mnt->mnt_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, mnt->mnt_sb);
-
-        /* optional statistics */
-        if (mnt->mnt_sb->s_op->show_stats) {
-                seq_putc(m, ' ');
-                if (!err)
-                        err = mnt->mnt_sb->s_op->show_stats(m, mnt);
-        }
-
-        seq_putc(m, '\n');
-        return err;
-}
-
-const struct seq_operations mountstats_op = {
-        .start  = m_start,
-        .next   = m_next,
-        .stop   = m_stop,
-        .show   = show_vfsstat,
+        .show   = m_show,
 };
 #endif  /* CONFIG_PROC_FS */
 
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 851ba3dcdc29..07446b55b7cc 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -631,120 +631,6 @@ static const struct inode_operations proc_def_inode_operations = {
         .setattr        = proc_setattr,
 };
 
-static int mounts_open_common(struct inode *inode, struct file *file,
-                              const struct seq_operations *op)
-{
-        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) {
-                rcu_read_lock();
-                nsp = task_nsproxy(task);
-                if (nsp) {
-                        ns = nsp->mnt_ns;
-                        if (ns)
-                                get_mnt_ns(ns);
-                }
-                rcu_read_unlock();
-                if (ns && get_task_root(task, &root) == 0)
-                        ret = 0;
-                put_task_struct(task);
-        }
-
-        if (!ns)
-                goto err;
-        if (ret)
-                goto err_put_ns;
-
-        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, op);
-        if (ret)
-                goto err_free;
-
-        p->m.private = p;
-        p->ns = ns;
-        p->root = root;
-        p->m.poll_event = ns->event;
-
-        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 unsigned mounts_poll(struct file *file, poll_table *wait)
-{
-        struct proc_mounts *p = file->private_data;
-        unsigned res = POLLIN | POLLRDNORM;
-
-        poll_wait(file, &p->ns->poll, wait);
-        if (mnt_had_events(p))
-                res |= POLLERR | POLLPRI;
-
-        return res;
-}
-
-static int mounts_open(struct inode *inode, struct file *file)
-{
-        return mounts_open_common(inode, file, &mounts_op);
-}
-
-static const struct file_operations proc_mounts_operations = {
-        .open           = mounts_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = mounts_release,
-        .poll           = mounts_poll,
-};
-
-static int mountinfo_open(struct inode *inode, struct file *file)
-{
-        return mounts_open_common(inode, file, &mountinfo_op);
-}
-
-static const struct file_operations proc_mountinfo_operations = {
-        .open           = mountinfo_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = mounts_release,
-        .poll           = mounts_poll,
-};
-
-static int mountstats_open(struct inode *inode, struct file *file)
-{
-        return mounts_open_common(inode, file, &mountstats_op);
-}
-
-static const struct file_operations proc_mountstats_operations = {
-        .open           = mountstats_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = mounts_release,
-};
-
 #define PROC_BLOCK_SIZE (3*1024)                /* 4K page size but our output routines use some slack for overruns */
 
 static ssize_t proc_info_read(struct file * file, char __user * buf,
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
new file mode 100644
index 000000000000..9dcd9543ca12
--- /dev/null
+++ b/fs/proc_namespace.c
@@ -0,0 +1,331 @@
+/*
+ * 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 };
+        int err = 0;
+
+        /* device */
+        if (mnt->mnt_sb->s_op->show_devname) {
+                seq_puts(m, "device ");
+                err = mnt->mnt_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, mnt->mnt_sb);
+
+        /* optional statistics */
+        if (mnt->mnt_sb->s_op->show_stats) {
+                seq_putc(m, ' ');
+                if (!err)
+                        err = mnt->mnt_sb->s_op->show_stats(m, mnt);
+        }
+
+        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,
+};