From: Felix Fietkau Subject: jffs2: add RENAME_EXCHANGE support Signed-off-by: Felix Fietkau --- --- a/fs/jffs2/dir.c +++ b/fs/jffs2/dir.c @@ -787,18 +787,31 @@ static int jffs2_rename (struct user_nam int ret; struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb); struct jffs2_inode_info *victim_f = NULL; + struct inode *fst_inode = d_inode(old_dentry); + struct inode *snd_inode = d_inode(new_dentry); uint8_t type; uint32_t now; - if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT)) + if (flags & ~(RENAME_NOREPLACE|RENAME_WHITEOUT|RENAME_EXCHANGE)) return -EINVAL; + if ((flags & RENAME_EXCHANGE) && (old_dir_i != new_dir_i)) { + if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) { + inc_nlink(new_dir_i); + drop_nlink(old_dir_i); + } + else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) { + drop_nlink(new_dir_i); + inc_nlink(old_dir_i); + } + } + /* The VFS will check for us and prevent trying to rename a * file over a directory and vice versa, but if it's a directory, * the VFS can't check whether the victim is empty. The filesystem * needs to do that for itself. */ - if (d_really_is_positive(new_dentry)) { + if (d_really_is_positive(new_dentry) && !(flags & RENAME_EXCHANGE)) { victim_f = JFFS2_INODE_INFO(d_inode(new_dentry)); if (d_is_dir(new_dentry)) { struct jffs2_full_dirent *fd; @@ -833,7 +846,7 @@ static int jffs2_rename (struct user_nam if (ret) return ret; - if (victim_f) { + if (victim_f && !(flags & RENAME_EXCHANGE)) { /* There was a victim. Kill it off nicely */ if (d_is_dir(new_dentry)) clear_nlink(d_inode(new_dentry)); @@ -859,6 +872,12 @@ static int jffs2_rename (struct user_nam if (flags & RENAME_WHITEOUT) /* Replace with whiteout */ ret = jffs2_whiteout(mnt_userns, old_dir_i, old_dentry); + else if (flags & RENAME_EXCHANGE) + /* Replace the original */ + ret = jffs2_do_link(c, JFFS2_INODE_INFO(old_dir_i), + d_inode(new_dentry)->i_ino, type, + old_dentry->d_name.name, old_dentry->d_name.len, + now); else /* Unlink the original */ ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i), @@ -890,7 +909,7 @@ static int jffs2_rename (struct user_nam return ret; } - if (d_is_dir(old_dentry)) + if (d_is_dir(old_dentry) && !(flags & RENAME_EXCHANGE)) drop_nlink(old_dir_i); new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);