diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2009-03-30 20:36:33 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-05-08 15:45:07 -0700 |
| commit | 617629fabc23a797c6f76d9514e198b2097395da (patch) | |
| tree | 9c866bf9d9fb2183bad8f07c37df57fa1770351a /fs | |
| parent | 5cda02631f54f8aa8c5b4d53dff385ad591cd2ad (diff) | |
Get rid of bumping fs_struct refcount in pivot_root(2)
commit f8ef3ed2bebd2c4cb9ece92efa185d7aead8831a upstream.
Not because execve races with _that_ are serious - we really
need a situation when final drop of fs_struct refcount is
done by something that used to have it as current->fs.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 06f8e63f6cb..580b8d38d68 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2127,25 +2127,33 @@ static void chroot_fs_refs(struct path *old_root, struct path *new_root) { struct task_struct *g, *p; struct fs_struct *fs; + int count = 0; read_lock(&tasklist_lock); do_each_thread(g, p) { task_lock(p); fs = p->fs; if (fs) { - atomic_inc(&fs->count); - task_unlock(p); + write_lock(&fs->lock); if (fs->root.dentry == old_root->dentry - && fs->root.mnt == old_root->mnt) - set_fs_root(fs, new_root); + && fs->root.mnt == old_root->mnt) { + path_get(new_root); + fs->root = *new_root; + count++; + } if (fs->pwd.dentry == old_root->dentry - && fs->pwd.mnt == old_root->mnt) - set_fs_pwd(fs, new_root); - put_fs_struct(fs); - } else - task_unlock(p); + && fs->pwd.mnt == old_root->mnt) { + path_get(new_root); + fs->pwd = *new_root; + count++; + } + write_unlock(&fs->lock); + } + task_unlock(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); + while (count--) + path_put(old_root); } /* |