move handle_dots(), follow_dotdot() and follow_dotdot_rcu() past step_into()
pure move; we are going to have step_into() called by that bunch. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
Родитель
c9a0f75d81
Коммит
957dd41d88
260
fs/namei.c
260
fs/namei.c
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@ -1363,70 +1363,6 @@ static inline int handle_mounts(struct nameidata *nd, struct dentry *dentry,
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return ret;
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}
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static int follow_dotdot_rcu(struct nameidata *nd)
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{
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struct dentry *parent = NULL;
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struct inode *inode = nd->inode;
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unsigned seq;
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while (1) {
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if (path_equal(&nd->path, &nd->root))
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break;
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if (nd->path.dentry != nd->path.mnt->mnt_root) {
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struct dentry *old = nd->path.dentry;
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parent = old->d_parent;
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inode = parent->d_inode;
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seq = read_seqcount_begin(&parent->d_seq);
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if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))
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return -ECHILD;
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if (unlikely(!path_connected(nd->path.mnt, parent)))
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return -ECHILD;
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break;
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} else {
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struct mount *mnt = real_mount(nd->path.mnt);
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struct mount *mparent = mnt->mnt_parent;
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struct dentry *mountpoint = mnt->mnt_mountpoint;
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struct inode *inode2 = mountpoint->d_inode;
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unsigned seq = read_seqcount_begin(&mountpoint->d_seq);
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if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
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return -ECHILD;
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if (&mparent->mnt == nd->path.mnt)
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -ECHILD;
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/* we know that mountpoint was pinned */
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nd->path.dentry = mountpoint;
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nd->path.mnt = &mparent->mnt;
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inode = inode2;
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nd->seq = seq;
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}
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}
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if (unlikely(!parent)) {
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if (unlikely(nd->flags & LOOKUP_BENEATH))
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return -ECHILD;
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} else {
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nd->path.dentry = parent;
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nd->seq = seq;
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}
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while (unlikely(d_mountpoint(nd->path.dentry))) {
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struct mount *mounted;
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mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
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if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
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return -ECHILD;
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if (!mounted)
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -ECHILD;
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nd->path.mnt = &mounted->mnt;
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nd->path.dentry = mounted->mnt.mnt_root;
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inode = nd->path.dentry->d_inode;
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nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
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}
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nd->inode = inode;
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return 0;
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}
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/*
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* Skip to top of mountpoint pile in refwalk mode for follow_dotdot()
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*/
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@ -1443,38 +1379,6 @@ static void follow_mount(struct path *path)
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}
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}
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static int follow_dotdot(struct nameidata *nd)
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{
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struct dentry *parent = NULL;
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while (1) {
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if (path_equal(&nd->path, &nd->root))
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break;
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if (nd->path.dentry != nd->path.mnt->mnt_root) {
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/* rare case of legitimate dget_parent()... */
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parent = dget_parent(nd->path.dentry);
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if (unlikely(!path_connected(nd->path.mnt, parent))) {
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dput(parent);
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return -ENOENT;
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}
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break;
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}
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if (!follow_up(&nd->path))
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -EXDEV;
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}
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if (unlikely(!parent)) {
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if (unlikely(nd->flags & LOOKUP_BENEATH))
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return -EXDEV;
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} else {
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dput(nd->path.dentry);
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nd->path.dentry = parent;
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}
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follow_mount(&nd->path);
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nd->inode = nd->path.dentry->d_inode;
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return 0;
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}
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/*
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* This looks up the name in dcache and possibly revalidates the found dentry.
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* NULL is returned if the dentry does not exist in the cache.
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@ -1654,40 +1558,6 @@ static inline int may_lookup(struct nameidata *nd)
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return inode_permission(nd->inode, MAY_EXEC);
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}
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static inline int handle_dots(struct nameidata *nd, int type)
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{
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if (type == LAST_DOTDOT) {
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int error = 0;
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if (!nd->root.mnt) {
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error = set_root(nd);
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if (error)
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return error;
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}
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if (nd->flags & LOOKUP_RCU)
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error = follow_dotdot_rcu(nd);
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else
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error = follow_dotdot(nd);
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if (error)
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return error;
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if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) {
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/*
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* If there was a racing rename or mount along our
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* path, then we can't be sure that ".." hasn't jumped
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* above nd->root (and so userspace should retry or use
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* some fallback).
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*/
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smp_rmb();
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if (unlikely(__read_seqcount_retry(&mount_lock.seqcount, nd->m_seq)))
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return -EAGAIN;
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if (unlikely(__read_seqcount_retry(&rename_lock.seqcount, nd->r_seq)))
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return -EAGAIN;
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}
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}
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return 0;
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}
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enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4};
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static const char *pick_link(struct nameidata *nd, struct path *link,
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@ -1817,6 +1687,136 @@ static const char *step_into(struct nameidata *nd, int flags,
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return pick_link(nd, &path, inode, seq, flags);
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}
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static int follow_dotdot_rcu(struct nameidata *nd)
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{
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struct dentry *parent = NULL;
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struct inode *inode = nd->inode;
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unsigned seq;
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while (1) {
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if (path_equal(&nd->path, &nd->root))
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break;
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if (nd->path.dentry != nd->path.mnt->mnt_root) {
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struct dentry *old = nd->path.dentry;
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parent = old->d_parent;
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inode = parent->d_inode;
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seq = read_seqcount_begin(&parent->d_seq);
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if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))
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return -ECHILD;
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if (unlikely(!path_connected(nd->path.mnt, parent)))
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return -ECHILD;
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break;
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} else {
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struct mount *mnt = real_mount(nd->path.mnt);
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struct mount *mparent = mnt->mnt_parent;
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struct dentry *mountpoint = mnt->mnt_mountpoint;
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struct inode *inode2 = mountpoint->d_inode;
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unsigned seq = read_seqcount_begin(&mountpoint->d_seq);
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if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
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return -ECHILD;
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if (&mparent->mnt == nd->path.mnt)
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -ECHILD;
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/* we know that mountpoint was pinned */
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nd->path.dentry = mountpoint;
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nd->path.mnt = &mparent->mnt;
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inode = inode2;
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nd->seq = seq;
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}
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}
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if (unlikely(!parent)) {
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if (unlikely(nd->flags & LOOKUP_BENEATH))
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return -ECHILD;
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} else {
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nd->path.dentry = parent;
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nd->seq = seq;
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}
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while (unlikely(d_mountpoint(nd->path.dentry))) {
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struct mount *mounted;
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mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
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if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
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return -ECHILD;
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if (!mounted)
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -ECHILD;
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nd->path.mnt = &mounted->mnt;
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nd->path.dentry = mounted->mnt.mnt_root;
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inode = nd->path.dentry->d_inode;
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nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
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}
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nd->inode = inode;
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return 0;
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}
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static int follow_dotdot(struct nameidata *nd)
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{
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struct dentry *parent = NULL;
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while (1) {
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if (path_equal(&nd->path, &nd->root))
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break;
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if (nd->path.dentry != nd->path.mnt->mnt_root) {
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/* rare case of legitimate dget_parent()... */
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parent = dget_parent(nd->path.dentry);
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if (unlikely(!path_connected(nd->path.mnt, parent))) {
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dput(parent);
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return -ENOENT;
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}
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break;
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}
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if (!follow_up(&nd->path))
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break;
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if (unlikely(nd->flags & LOOKUP_NO_XDEV))
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return -EXDEV;
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}
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if (unlikely(!parent)) {
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if (unlikely(nd->flags & LOOKUP_BENEATH))
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return -EXDEV;
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} else {
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dput(nd->path.dentry);
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nd->path.dentry = parent;
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}
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follow_mount(&nd->path);
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nd->inode = nd->path.dentry->d_inode;
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return 0;
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}
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static inline int handle_dots(struct nameidata *nd, int type)
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{
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if (type == LAST_DOTDOT) {
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int error = 0;
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if (!nd->root.mnt) {
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error = set_root(nd);
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if (error)
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return error;
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}
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if (nd->flags & LOOKUP_RCU)
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error = follow_dotdot_rcu(nd);
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else
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error = follow_dotdot(nd);
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if (error)
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return error;
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if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) {
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/*
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* If there was a racing rename or mount along our
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* path, then we can't be sure that ".." hasn't jumped
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* above nd->root (and so userspace should retry or use
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* some fallback).
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*/
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smp_rmb();
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if (unlikely(__read_seqcount_retry(&mount_lock.seqcount, nd->m_seq)))
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return -EAGAIN;
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if (unlikely(__read_seqcount_retry(&rename_lock.seqcount, nd->r_seq)))
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return -EAGAIN;
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}
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}
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return 0;
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}
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static const char *walk_component(struct nameidata *nd, int flags)
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{
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struct dentry *dentry;
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