diff options
| -rw-r--r-- | fs/namei.c | 77 |
1 files changed, 45 insertions, 32 deletions
diff --git a/fs/namei.c b/fs/namei.c index fda239b9baff..8cfbd5fd0c78 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1691,21 +1691,12 @@ static struct dentry *follow_dotdot_rcu(struct nameidata *nd, struct inode **inodep, unsigned *seqp) { - while (1) { - if (path_equal(&nd->path, &nd->root)) - break; - if (nd->path.dentry != nd->path.mnt->mnt_root) { - struct dentry *old = nd->path.dentry; - struct dentry *parent = old->d_parent; + struct dentry *parent, *old; - *inodep = parent->d_inode; - *seqp = read_seqcount_begin(&parent->d_seq); - if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq))) - return ERR_PTR(-ECHILD); - if (unlikely(!path_connected(nd->path.mnt, parent))) - return ERR_PTR(-ECHILD); - return parent; - } else { + if (path_equal(&nd->path, &nd->root)) + goto in_root; + if (unlikely(nd->path.dentry == nd->path.mnt->mnt_root)) { + while (1) { struct mount *mnt = real_mount(nd->path.mnt); struct mount *mparent = mnt->mnt_parent; struct dentry *mountpoint = mnt->mnt_mountpoint; @@ -1714,7 +1705,7 @@ static struct dentry *follow_dotdot_rcu(struct nameidata *nd, if (unlikely(read_seqretry(&mount_lock, nd->m_seq))) return ERR_PTR(-ECHILD); if (&mparent->mnt == nd->path.mnt) - break; + goto in_root; if (unlikely(nd->flags & LOOKUP_NO_XDEV)) return ERR_PTR(-ECHILD); /* we know that mountpoint was pinned */ @@ -1722,8 +1713,22 @@ static struct dentry *follow_dotdot_rcu(struct nameidata *nd, nd->path.mnt = &mparent->mnt; nd->inode = inode; nd->seq = seq; + if (path_equal(&nd->path, &nd->root)) + goto in_root; + if (nd->path.dentry != nd->path.mnt->mnt_root) + break; } } + old = nd->path.dentry; + parent = old->d_parent; + *inodep = parent->d_inode; + *seqp = read_seqcount_begin(&parent->d_seq); + if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq))) + return ERR_PTR(-ECHILD); + if (unlikely(!path_connected(nd->path.mnt, parent))) + return ERR_PTR(-ECHILD); + return parent; +in_root: if (unlikely(nd->flags & LOOKUP_BENEATH)) return ERR_PTR(-ECHILD); return NULL; @@ -1733,25 +1738,33 @@ static struct dentry *follow_dotdot(struct nameidata *nd, struct inode **inodep, unsigned *seqp) { - while (1) { - if (path_equal(&nd->path, &nd->root)) - break; - if (nd->path.dentry != nd->path.mnt->mnt_root) { - /* rare case of legitimate dget_parent()... */ - struct dentry *parent = dget_parent(nd->path.dentry); - if (unlikely(!path_connected(nd->path.mnt, parent))) { - dput(parent); - return ERR_PTR(-ENOENT); - } - *seqp = 0; - *inodep = parent->d_inode; - return parent; + struct dentry *parent; + + if (path_equal(&nd->path, &nd->root)) + goto in_root; + if (unlikely(nd->path.dentry == nd->path.mnt->mnt_root)) { + while (1) { + if (!follow_up(&nd->path)) + goto in_root; + if (unlikely(nd->flags & LOOKUP_NO_XDEV)) + return ERR_PTR(-EXDEV); + if (path_equal(&nd->path, &nd->root)) + goto in_root; + if (nd->path.dentry != nd->path.mnt->mnt_root) + break; } - if (!follow_up(&nd->path)) - break; - if (unlikely(nd->flags & LOOKUP_NO_XDEV)) - return ERR_PTR(-EXDEV); } + /* rare case of legitimate dget_parent()... */ + parent = dget_parent(nd->path.dentry); + if (unlikely(!path_connected(nd->path.mnt, parent))) { + dput(parent); + return ERR_PTR(-ENOENT); + } + *seqp = 0; + *inodep = parent->d_inode; + return parent; + +in_root: if (unlikely(nd->flags & LOOKUP_BENEATH)) return ERR_PTR(-EXDEV); dget(nd->path.dentry); |