From 17b312c5d86909bd53da5a49cd4589a17f97c439 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Oct 2023 14:44:23 -0400 Subject: [PATCH] udf_rename(): only access the child content on cross-directory rename [ Upstream commit 9d35cebb794bb7be93db76c3383979c7deacfef9 ] We can't really afford locking the source on same-directory rename; currently vfs_rename() tries to do that, but it will have to be changed. The logics in udf_rename() is lazy and goes looking for ".." in source even in same-directory case. It's not hard to get rid of that, leaving that behaviour only for cross-directory case; that VFS can get locks safely (and will keep doing that after the coming changes). Reviewed-by: Jan Kara Signed-off-by: Al Viro Stable-dep-of: 6756af923e06 ("udf: Verify inode link counts before performing rename") Signed-off-by: Sasha Levin --- fs/udf/namei.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/udf/namei.c b/fs/udf/namei.c index b3f57ad2b869..0461a7b1e9b4 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -770,7 +770,7 @@ static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir, struct inode *old_inode = d_inode(old_dentry); struct inode *new_inode = d_inode(new_dentry); struct udf_fileident_iter oiter, niter, diriter; - bool has_diriter = false; + bool has_diriter = false, is_dir = false; int retval; struct kernel_lb_addr tloc; @@ -793,6 +793,9 @@ static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir, if (!empty_dir(new_inode)) goto out_oiter; } + is_dir = true; + } + if (is_dir && old_dir != new_dir) { retval = udf_fiiter_find_entry(old_inode, &dotdot_name, &diriter); if (retval == -ENOENT) { @@ -880,7 +883,9 @@ static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir, cpu_to_lelb(UDF_I(new_dir)->i_location); udf_fiiter_write_fi(&diriter, NULL); udf_fiiter_release(&diriter); + } + if (is_dir) { inode_dec_link_count(old_dir); if (new_inode) inode_dec_link_count(new_inode);