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-rw-r--r--fs/namespace.c30
1 files changed, 22 insertions, 8 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index c6f54e4c4290..134d494158d9 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -695,12 +695,16 @@ static inline void mangle(struct seq_file *m, const char *s)
*/
int generic_show_options(struct seq_file *m, struct vfsmount *mnt)
{
- const char *options = mnt->mnt_sb->s_options;
+ const char *options;
+
+ rcu_read_lock();
+ options = rcu_dereference(mnt->mnt_sb->s_options);
if (options != NULL && options[0]) {
seq_putc(m, ',');
mangle(m, options);
}
+ rcu_read_unlock();
return 0;
}
@@ -721,11 +725,22 @@ EXPORT_SYMBOL(generic_show_options);
*/
void save_mount_options(struct super_block *sb, char *options)
{
- kfree(sb->s_options);
- sb->s_options = kstrdup(options, GFP_KERNEL);
+ BUG_ON(sb->s_options);
+ rcu_assign_pointer(sb->s_options, kstrdup(options, GFP_KERNEL));
}
EXPORT_SYMBOL(save_mount_options);
+void replace_mount_options(struct super_block *sb, char *options)
+{
+ char *old = sb->s_options;
+ rcu_assign_pointer(sb->s_options, options);
+ if (old) {
+ synchronize_rcu();
+ kfree(old);
+ }
+}
+EXPORT_SYMBOL(replace_mount_options);
+
#ifdef CONFIG_PROC_FS
/* iterator */
static void *m_start(struct seq_file *m, loff_t *pos)
@@ -1073,9 +1088,7 @@ static int do_umount(struct vfsmount *mnt, int flags)
*/
if (flags & MNT_FORCE && sb->s_op->umount_begin) {
- lock_kernel();
sb->s_op->umount_begin(sb);
- unlock_kernel();
}
/*
@@ -1377,7 +1390,7 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
if (parent_path) {
detach_mnt(source_mnt, parent_path);
attach_mnt(source_mnt, path);
- touch_mnt_namespace(current->nsproxy->mnt_ns);
+ touch_mnt_namespace(parent_path->mnt->mnt_ns);
} else {
mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt);
commit_tree(source_mnt);
@@ -1920,8 +1933,9 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
if (data_page)
((char *)data_page)[PAGE_SIZE - 1] = 0;
- /* Default to relatime */
- mnt_flags |= MNT_RELATIME;
+ /* Default to relatime unless overriden */
+ if (!(flags & MS_NOATIME))
+ mnt_flags |= MNT_RELATIME;
/* Separate the per-mountpoint flags */
if (flags & MS_NOSUID)