*/
#include <linux/syscalls.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/percpu.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/acct.h>
+#include <linux/export.h>
#include <linux/capability.h>
-#include <linux/cpumask.h>
-#include <linux/module.h>
-#include <linux/sysfs.h>
-#include <linux/seq_file.h>
#include <linux/mnt_namespace.h>
#include <linux/namei.h>
-#include <linux/nsproxy.h>
#include <linux/security.h>
-#include <linux/mount.h>
-#include <linux/ramfs.h>
-#include <linux/log2.h>
#include <linux/idr.h>
-#include <linux/fs_struct.h>
-#include <linux/fsnotify.h>
-#include <asm/uaccess.h>
-#include <asm/unistd.h>
+#include <linux/acct.h> /* acct_auto_close_mnt */
+#include <linux/ramfs.h> /* init_rootfs */
+#include <linux/fs_struct.h> /* get_fs_root et.al. */
+#include <linux/fsnotify.h> /* fsnotify_vfsmount_delete */
+#include <linux/uaccess.h>
#include "pnode.h"
#include "internal.h"
#endif
}
+static int mnt_is_readonly(struct vfsmount *mnt)
+{
+ if (mnt->mnt_sb->s_readonly_remount)
+ return 1;
+ /* Order wrt setting s_flags/s_readonly_remount in do_remount() */
+ smp_rmb();
+ return __mnt_is_readonly(mnt);
+}
+
/*
* Most r/o checks on a fs are for operations that take
* discrete amounts of time, like a write() or unlink().
* MNT_WRITE_HOLD is cleared.
*/
smp_rmb();
- if (__mnt_is_readonly(m)) {
+ if (mnt_is_readonly(m)) {
mnt_dec_writers(mnt);
ret = -EROFS;
- goto out;
}
-out:
preempt_enable();
return ret;
}
br_write_unlock(vfsmount_lock);
}
+int sb_prepare_remount_readonly(struct super_block *sb)
+{
+ struct mount *mnt;
+ int err = 0;
+
+ /* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */
+ if (atomic_long_read(&sb->s_remove_count))
+ return -EBUSY;
+
+ br_write_lock(vfsmount_lock);
+ list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
+ if (!(mnt->mnt.mnt_flags & MNT_READONLY)) {
+ mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
+ smp_mb();
+ if (mnt_get_writers(mnt) > 0) {
+ err = -EBUSY;
+ break;
+ }
+ }
+ }
+ if (!err && atomic_long_read(&sb->s_remove_count))
+ err = -EBUSY;
+
+ if (!err) {
+ sb->s_readonly_remount = 1;
+ smp_wmb();
+ }
+ list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
+ if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
+ mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
+ }
+ br_write_unlock(vfsmount_lock);
+
+ return err;
+}
+
static void free_vfsmnt(struct mount *mnt)
{
kfree(mnt->mnt_devname);
mnt->mnt.mnt_sb = root->d_sb;
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
return &mnt->mnt;
}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
mnt->mnt.mnt_root = dget(root);
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
mnt->mnt_parent = mnt;
+ br_write_lock(vfsmount_lock);
+ list_add_tail(&mnt->mnt_instance, &sb->s_mounts);
+ br_write_unlock(vfsmount_lock);
if (flag & CL_SLAVE) {
list_add(&mnt->mnt_slave, &old->mnt_slave_list);
acct_auto_close_mnt(&mnt->mnt);
goto put_again;
}
+ list_del(&mnt->mnt_instance);
br_write_unlock(vfsmount_lock);
mntfree(mnt);
}
*
* See also save_mount_options().
*/
-int generic_show_options(struct seq_file *m, struct vfsmount *mnt)
+int generic_show_options(struct seq_file *m, struct dentry *root)
{
const char *options;
rcu_read_lock();
- options = rcu_dereference(mnt->mnt_sb->s_options);
+ options = rcu_dereference(root->d_sb->s_options);
if (options != NULL && options[0]) {
seq_putc(m, ',');
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);
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);
}
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 */
struct mnt_namespace *new_ns;
struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
struct mount *p, *q;
- struct mount *old = real_mount(mnt_ns->root);
+ struct mount *old = mnt_ns->root;
struct mount *new;
new_ns = alloc_mnt_ns();
kfree(new_ns);
return ERR_PTR(-ENOMEM);
}
- new_ns->root = &new->mnt;
+ new_ns->root = new;
br_write_lock(vfsmount_lock);
list_add_tail(&new_ns->list, &new->mnt_list);
br_write_unlock(vfsmount_lock);
struct mount *mnt = real_mount(m);
mnt->mnt_ns = new_ns;
__mnt_make_longterm(mnt);
- new_ns->root = m;
+ new_ns->root = mnt;
list_add(&new_ns->list, &mnt->mnt_list);
} else {
mntput(m);
init_task.nsproxy->mnt_ns = ns;
get_mnt_ns(ns);
- root.mnt = ns->root;
- root.dentry = ns->root->mnt_root;
+ root.mnt = mnt;
+ root.dentry = mnt->mnt_root;
set_fs_pwd(current->fs, &root);
set_fs_root(current->fs, &root);
return;
down_write(&namespace_sem);
br_write_lock(vfsmount_lock);
- umount_tree(real_mount(ns->root), 0, &umount_list);
+ umount_tree(ns->root, 0, &umount_list);
br_write_unlock(vfsmount_lock);
up_write(&namespace_sem);
release_mounts(&umount_list);
projects / linux-flexiantxendom0-3.2.10.git / blobdiff