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vfs: rename: use common code for dir and non-dir
There's actually very little difference between vfs_rename_dir() and vfs_rename_other() so move both inline into vfs_rename() which still stays reasonably readable. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reviewed-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Miklos Szeredi
parent
de22a4c372
commit
bc27027a73
217
fs/namei.c
217
fs/namei.c
@ -3973,7 +3973,27 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
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return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
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}
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/*
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/**
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* vfs_rename - rename a filesystem object
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* @old_dir: parent of source
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* @old_dentry: source
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* @new_dir: parent of destination
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* @new_dentry: destination
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* @delegated_inode: returns an inode needing a delegation break
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*
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* The caller must hold multiple mutexes--see lock_rename()).
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*
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* If vfs_rename discovers a delegation in need of breaking at either
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* the source or destination, it will return -EWOULDBLOCK and return a
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* reference to the inode in delegated_inode. The caller should then
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* break the delegation and retry. Because breaking a delegation may
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* take a long time, the caller should drop all locks before doing
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* so.
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*
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* Alternatively, a caller may pass NULL for delegated_inode. This may
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* be appropriate for callers that expect the underlying filesystem not
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* to be NFS exported.
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*
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* The worst of all namespace operations - renaming directory. "Perverted"
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* doesn't even start to describe it. Somebody in UCB had a heck of a trip...
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* Problems:
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@ -4001,137 +4021,24 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
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* ->i_mutex on parents, which works but leads to some truly excessive
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* locking].
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*/
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static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry)
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{
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int error = 0;
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struct inode *target = new_dentry->d_inode;
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unsigned max_links = new_dir->i_sb->s_max_links;
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/*
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* If we are going to change the parent - check write permissions,
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* we'll need to flip '..'.
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*/
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if (new_dir != old_dir) {
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error = inode_permission(old_dentry->d_inode, MAY_WRITE);
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if (error)
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return error;
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}
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error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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return error;
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dget(new_dentry);
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if (target)
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mutex_lock(&target->i_mutex);
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error = -EBUSY;
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if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
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goto out;
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error = -EMLINK;
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if (max_links && !target && new_dir != old_dir &&
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new_dir->i_nlink >= max_links)
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goto out;
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if (target)
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shrink_dcache_parent(new_dentry);
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error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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goto out;
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if (target) {
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target->i_flags |= S_DEAD;
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dont_mount(new_dentry);
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}
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if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
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d_move(old_dentry, new_dentry);
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out:
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if (target)
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mutex_unlock(&target->i_mutex);
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dput(new_dentry);
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return error;
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}
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static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry,
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struct inode **delegated_inode)
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{
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struct inode *target = new_dentry->d_inode;
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struct inode *source = old_dentry->d_inode;
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int error;
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error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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return error;
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dget(new_dentry);
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lock_two_nondirectories(source, target);
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error = -EBUSY;
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if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
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goto out;
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error = try_break_deleg(source, delegated_inode);
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if (error)
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goto out;
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if (target) {
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error = try_break_deleg(target, delegated_inode);
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if (error)
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goto out;
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}
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error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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goto out;
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if (target)
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dont_mount(new_dentry);
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if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
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d_move(old_dentry, new_dentry);
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out:
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unlock_two_nondirectories(source, target);
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dput(new_dentry);
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return error;
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}
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/**
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* vfs_rename - rename a filesystem object
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* @old_dir: parent of source
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* @old_dentry: source
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* @new_dir: parent of destination
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* @new_dentry: destination
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* @delegated_inode: returns an inode needing a delegation break
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*
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* The caller must hold multiple mutexes--see lock_rename()).
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*
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* If vfs_rename discovers a delegation in need of breaking at either
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* the source or destination, it will return -EWOULDBLOCK and return a
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* reference to the inode in delegated_inode. The caller should then
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* break the delegation and retry. Because breaking a delegation may
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* take a long time, the caller should drop all locks before doing
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* so.
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*
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* Alternatively, a caller may pass NULL for delegated_inode. This may
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* be appropriate for callers that expect the underlying filesystem not
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* to be NFS exported.
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*/
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int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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struct inode *new_dir, struct dentry *new_dentry,
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struct inode **delegated_inode)
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{
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int error;
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int is_dir = d_is_dir(old_dentry);
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bool is_dir = d_is_dir(old_dentry);
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const unsigned char *old_name;
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struct inode *source = old_dentry->d_inode;
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struct inode *target = new_dentry->d_inode;
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if (source == target)
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return 0;
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if (old_dentry->d_inode == new_dentry->d_inode)
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return 0;
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error = may_delete(old_dir, old_dentry, is_dir);
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if (error)
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return error;
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if (!new_dentry->d_inode)
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if (!target)
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error = may_create(new_dir, new_dentry);
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else
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error = may_delete(new_dir, new_dentry, is_dir);
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@ -4141,15 +4048,71 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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if (!old_dir->i_op->rename)
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return -EPERM;
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old_name = fsnotify_oldname_init(old_dentry->d_name.name);
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/*
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* If we are going to change the parent - check write permissions,
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* we'll need to flip '..'.
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*/
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if (is_dir && new_dir != old_dir) {
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error = inode_permission(source, MAY_WRITE);
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if (error)
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return error;
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}
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if (is_dir)
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error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
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else
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error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode);
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error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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return error;
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old_name = fsnotify_oldname_init(old_dentry->d_name.name);
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dget(new_dentry);
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if (!is_dir)
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lock_two_nondirectories(source, target);
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else if (target)
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mutex_lock(&target->i_mutex);
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error = -EBUSY;
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if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
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goto out;
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if (is_dir) {
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unsigned max_links = new_dir->i_sb->s_max_links;
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error = -EMLINK;
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if (max_links && !target && new_dir != old_dir &&
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new_dir->i_nlink >= max_links)
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goto out;
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if (target)
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shrink_dcache_parent(new_dentry);
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} else {
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error = try_break_deleg(source, delegated_inode);
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if (error)
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goto out;
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if (target) {
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error = try_break_deleg(target, delegated_inode);
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if (error)
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goto out;
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}
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}
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error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
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if (error)
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goto out;
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if (target) {
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if (is_dir)
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target->i_flags |= S_DEAD;
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dont_mount(new_dentry);
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}
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if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
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d_move(old_dentry, new_dentry);
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out:
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if (!is_dir)
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unlock_two_nondirectories(source, target);
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else if (target)
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mutex_unlock(&target->i_mutex);
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dput(new_dentry);
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if (!error)
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fsnotify_move(old_dir, new_dir, old_name, is_dir,
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new_dentry->d_inode, old_dentry);
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target, old_dentry);
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fsnotify_oldname_free(old_name);
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return error;
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