From 37456771c58be10dd813fb4510035d0d67a969aa Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 23 Jul 2014 15:15:34 +0200 Subject: [PATCH] shmem: support RENAME_EXCHANGE This is really simple in tmpfs since the VFS already takes care of shuffling the dentries. Just adjust nlink on parent directories and touch c & mtimes. Signed-off-by: Miklos Szeredi Acked-by: Hugh Dickins Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- mm/shmem.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index fe959181f995..0f018002dd64 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2048,6 +2048,28 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry) return shmem_unlink(dir, dentry); } +static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) +{ + bool old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); + bool new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); + + if (old_dir != new_dir && old_is_dir != new_is_dir) { + if (old_is_dir) { + drop_nlink(old_dir); + inc_nlink(new_dir); + } else { + drop_nlink(new_dir); + inc_nlink(old_dir); + } + } + old_dir->i_ctime = old_dir->i_mtime = + new_dir->i_ctime = new_dir->i_mtime = + old_dentry->d_inode->i_ctime = + new_dentry->d_inode->i_ctime = CURRENT_TIME; + + return 0; +} + /* * The VFS layer already does all the dentry stuff for rename, * we just have to decrement the usage count for the target if @@ -2059,9 +2081,12 @@ static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struc struct inode *inode = old_dentry->d_inode; int they_are_dirs = S_ISDIR(inode->i_mode); - if (flags & ~(RENAME_NOREPLACE)) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) return -EINVAL; + if (flags & RENAME_EXCHANGE) + return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry); + if (!simple_empty(new_dentry)) return -ENOTEMPTY;