Guest additions 6.0.6+ build error, Debian Jessie -> fixed in 6.0.10

[thehunmonkgroup]

Guest additions after 6.0.4 do not build correctly on Debian Jessie guests.

I've tried building 6.0.6, 6.0.8, and the latest test build, all fail.

I can build the 6.0.4 guest additions successfully in this environment.

Attaching log output from my last attempt to build on 6.0.8.

[thehunmonkgroup]

Log file for build failure of Guest Additions 6.0.8 on Debian Jessie guest

[paulson]

The error message:

[...]  -o /tmp/vbox.0/.tmp_utils.o /tmp/vbox.0/utils.c
/tmp/vbox.0/utils.c: In function ‘vbsf_inode_setattr’:
/tmp/vbox.0/utils.c:808:5: error: implicit declaration of function ‘inode_change_ok’ [-Werror=implicit-function-declaration]
     rc = inode_change_ok(pInode, iattr);
     ^

shows that the function declaration of inode_change_ok() is not found when compiling utils.c. This function was removed in Linux kernel version 3.16.39 via the following changeset:

fs: Give dentry to inode_change_ok() instead of inode ​https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?id=50b070e8224f7bf86622ede1abee9fa3d3dc2f10

The inode_change_ok() function was replaced with setattr_prepare() which has a different function prototype in addition to a different name:

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 545837db9468..3b69a82bbdd9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2627,7 +2627,7 @@ extern int buffer_migrate_page(struct address_space *,
 #define buffer_migrate_page NULL
 #endif
 
-extern int inode_change_ok(const struct inode *, struct iattr *);
+extern int setattr_prepare(struct dentry *, struct iattr *);
 extern int inode_newsize_ok(const struct inode *, loff_t offset);
 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
 

The VirtualBox Guest Additions code appears to only call inode_change_ok() in this one place (utils.c:vbsf_inode_setattr()) and there is an applicable #ifdef already in place:

https://www.virtualbox.org/browser/vbox/trunk/src/VBox/Additions/linux/sharedfolders/utils.c

809     #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
810         rc = setattr_prepare(dentry, iattr);
811     #else
812         rc = inode_change_ok(pInode, iattr);
813     #endif

It looks like the fix is probably to change line 809 to check for KERNEL_VERSION(3, 16, 39).

Note also that a google search will show that this changeset has caused breakage for other consumers of this exported interface such as OpenAFS, ZFS on Linux, Yocto, and others.

[paulson]

This has been fixed in trunk revision r79594:

https://www.virtualbox.org/log/vbox/trunk/src/VBox/Additions/linux/sharedfolders/utils.c?rev=79594

The diffs can be seen here:

https://www.virtualbox.org/changeset?reponame=vbox&new=79594%40trunk%2Fsrc%2FVBox%2FAdditions%2Flinux%2Fsharedfolders%2Futils.c&old=78860%40trunk%2Fsrc%2FVBox%2FAdditions%2Flinux%2Fsharedfolders%2Futils.c

The fix is also part of VirtualBox 6.0.10 and any 6.0.x Testbuilds with a revision >= r131953. This issue doesn't apply to VirtualBox 5.2.x.