diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/namei.c b/fs/namei.c index 0b14f6910fc..86643302079 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -479,6 +479,14 @@ static int nameidata_dentry_drop_rcu(struct nameidata *nd, struct dentry *dentry struct fs_struct *fs = current->fs; struct dentry *parent = nd->path.dentry; + /* + * It can be possible to revalidate the dentry that we started + * the path walk with. force_reval_path may also revalidate the + * dentry already committed to the nameidata. + */ + if (unlikely(parent == dentry)) + return nameidata_drop_rcu(nd); + BUG_ON(!(nd->flags & LOOKUP_RCU)); if (nd->root.mnt) { spin_lock(&fs->lock); @@ -583,6 +591,13 @@ void release_open_intent(struct nameidata *nd) fput(nd->intent.open.file); } +/* + * Call d_revalidate and handle filesystems that request rcu-walk + * to be dropped. This may be called and return in rcu-walk mode, + * regardless of success or error. If -ECHILD is returned, the caller + * must return -ECHILD back up the path walk stack so path walk may + * be restarted in ref-walk mode. + */ static int d_revalidate(struct dentry *dentry, struct nameidata *nd) { int status; @@ -673,6 +688,9 @@ force_reval_path(struct path *path, struct nameidata *nd) return 0; if (!status) { + /* Don't d_invalidate in rcu-walk mode */ + if (nameidata_drop_rcu(nd)) + return -ECHILD; d_invalidate(dentry); status = -ESTALE; } @@ -2105,11 +2123,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path, dir = nd->path.dentry; case LAST_DOT: if (need_reval_dot(dir)) { - error = d_revalidate(nd->path.dentry, nd); - if (!error) - error = -ESTALE; - if (error < 0) + int status = d_revalidate(nd->path.dentry, nd); + if (!status) + status = -ESTALE; + if (status < 0) { + error = status; goto exit; + } } /* fallthrough */ case LAST_ROOT: |