From 741a295130606143edbf9fc740f633dbc1e6225f Mon Sep 17 00:00:00 2001 From: JANAK DESAI Date: Tue, 7 Feb 2006 12:59:00 -0800 Subject: [PATCH] unshare system call -v5: unshare namespace If the namespace structure is being shared, allocate a new one and copy information from the current, shared, structure. Signed-off-by: Janak Desai Cc: Al Viro Cc: Christoph Hellwig Cc: Michael Kerrisk Cc: Andi Kleen Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/namespace.c | 56 ++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 20 deletions(-) (limited to 'fs/namespace.c') diff --git a/fs/namespace.c b/fs/namespace.c index ce97becff4611c..a2bef5c8103359 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1325,27 +1325,17 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, return retval; } -int copy_namespace(int flags, struct task_struct *tsk) +/* + * Allocate a new namespace structure and populate it with contents + * copied from the namespace of the passed in task structure. + */ +struct namespace *dup_namespace(struct task_struct *tsk, struct fs_struct *fs) { struct namespace *namespace = tsk->namespace; struct namespace *new_ns; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; - struct fs_struct *fs = tsk->fs; struct vfsmount *p, *q; - if (!namespace) - return 0; - - get_namespace(namespace); - - if (!(flags & CLONE_NEWNS)) - return 0; - - if (!capable(CAP_SYS_ADMIN)) { - put_namespace(namespace); - return -EPERM; - } - new_ns = kmalloc(sizeof(struct namespace), GFP_KERNEL); if (!new_ns) goto out; @@ -1396,8 +1386,6 @@ int copy_namespace(int flags, struct task_struct *tsk) } up_write(&namespace_sem); - tsk->namespace = new_ns; - if (rootmnt) mntput(rootmnt); if (pwdmnt) @@ -1405,12 +1393,40 @@ int copy_namespace(int flags, struct task_struct *tsk) if (altrootmnt) mntput(altrootmnt); - put_namespace(namespace); - return 0; +out: + return new_ns; +} + +int copy_namespace(int flags, struct task_struct *tsk) +{ + struct namespace *namespace = tsk->namespace; + struct namespace *new_ns; + int err = 0; + + if (!namespace) + return 0; + + get_namespace(namespace); + + if (!(flags & CLONE_NEWNS)) + return 0; + + if (!capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out; + } + + new_ns = dup_namespace(tsk, tsk->fs); + if (!new_ns) { + err = -ENOMEM; + goto out; + } + + tsk->namespace = new_ns; out: put_namespace(namespace); - return -ENOMEM; + return err; } asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name, -- cgit 1.2.3-korg From f30ac319f1b91878cdc57a50930f15c36e0e103a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 1 Feb 2006 07:53:21 -0500 Subject: [PATCH] umount_tree() decrements mount count on wrong dentry Signed-off-by: Al Viro --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/namespace.c') diff --git a/fs/namespace.c b/fs/namespace.c index a2bef5c8103359..058a44865bebda 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -494,7 +494,7 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill) p->mnt_namespace = NULL; list_del_init(&p->mnt_child); if (p->mnt_parent != p) - mnt->mnt_mountpoint->d_mounted--; + p->mnt_mountpoint->d_mounted--; change_mnt_propagation(p, MS_PRIVATE); } } -- cgit 1.2.3-korg