Re: linux-next: build failure after merge of the staging tree

[Greg KH]

On Thu, Aug 02, 2018 at 03:01:59PM +0800, Chao Yu wrote:
> Hi Greg,
> 
> On 2018/8/2 14:15, Greg KH wrote:
> > On Wed, Aug 01, 2018 at 05:09:13PM +0800, Chao Yu wrote:
> >> Hi Stephen,
> >>
> >> On 2018/7/30 14:31, Gao Xiang wrote:
> >>> Hi Stephen,
> >>>
> >>> On 2018/7/30 14:16, Stephen Rothwell wrote:
> >>>> Hi Greg,
> >>>>
> >>>> After merging the staging tree, today's linux-next build (x86_64
> >>>> allmodconfig) failed like this:
> >>>>
> >>>> drivers/staging/erofs/super.c: In function 'erofs_read_super':
> >>>> drivers/staging/erofs/super.c:343:17: error: 'MS_RDONLY' undeclared (first use in this function); did you mean 'IS_RDONLY'?
> >>>>   sb->s_flags |= MS_RDONLY | MS_NOATIME;
> >>>>                  ^~~~~~~~~
> >>>>                  IS_RDONLY
> >>>> drivers/staging/erofs/super.c:343:17: note: each undeclared identifier is reported only once for each function it appears in
> >>>> drivers/staging/erofs/super.c:343:29: error: 'MS_NOATIME' undeclared (first use in this function); did you mean 'S_NOATIME'?
> >>>>   sb->s_flags |= MS_RDONLY | MS_NOATIME;
> >>>>                              ^~~~~~~~~~
> >>>>                              S_NOATIME
> >>>> drivers/staging/erofs/super.c: In function 'erofs_mount':
> >>>> drivers/staging/erofs/super.c:501:10: warning: passing argument 5 of 'mount_bdev' makes integer from pointer without a cast [-Wint-conversion]
> >>>>    &priv, erofs_fill_super);
> >>>>           ^~~~~~~~~~~~~~~~
> >>>> In file included from include/linux/buffer_head.h:12:0,
> >>>>                  from drivers/staging/erofs/super.c:14:
> >>>> include/linux/fs.h:2151:23: note: expected 'size_t {aka long unsigned int}' but argument is of type 'int (*)(struct super_block *, void *, int)'
> >>>>  extern struct dentry *mount_bdev(struct file_system_type *fs_type,
> >>>>                        ^~~~~~~~~~
> >>>> drivers/staging/erofs/super.c:500:9: error: too few arguments to function 'mount_bdev'
> >>>>   return mount_bdev(fs_type, flags, dev_name,
> >>>>          ^~~~~~~~~~
> >>>> In file included from include/linux/buffer_head.h:12:0,
> >>>>                  from drivers/staging/erofs/super.c:14:
> >>>> include/linux/fs.h:2151:23: note: declared here
> >>>>  extern struct dentry *mount_bdev(struct file_system_type *fs_type,
> >>>>                        ^~~~~~~~~~
> >>>> drivers/staging/erofs/super.c: At top level:
> >>>> drivers/staging/erofs/super.c:518:20: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
> >>>>   .mount          = erofs_mount,
> >>>>                     ^~~~~~~~~~~
> >>>> drivers/staging/erofs/super.c:518:20: note: (near initialization for 'erofs_fs_type.mount')
> >>>> drivers/staging/erofs/super.c: In function 'erofs_remount':
> >>>> drivers/staging/erofs/super.c:630:12: error: 'MS_RDONLY' undeclared (first use in this function); did you mean 'IS_RDONLY'?
> >>>>   *flags |= MS_RDONLY;
> >>>>             ^~~~~~~~~
> >>>>             IS_RDONLY
> >>>> drivers/staging/erofs/super.c: At top level:
> >>>> drivers/staging/erofs/super.c:640:16: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
> >>>>   .remount_fs = erofs_remount,
> >>>>                 ^~~~~~~~~~~~~
> >>>>
> >>>> Caused by various commits creating erofs in the staging tree interacting
> >>>> with various commits redoing the mount infrastructure in the vfs tree.
> >>>>
> >>>> I have disabed CONFIG_EROFS_FS for now:
> >>
> >> Xiang has submitted several patches as below to fix compiling error on -next
> >> tree, could you consider to merge those temporary fixes into -next after merging
> >> staging-next's updates, and reenable CONFIG_EROFS_FS for further integrity
> >> compiling and test?
> >>
> >> staging: erofs: fix superblock/inode flags (MS_RDONLY -> SB_RDONLY, S_NOATIME)
> >> https://lists.ozlabs.org/pipermail/linux-erofs/2018-July/000282.html
> >>
> >> staging: erofs: remove RADIX_TREE_EXCEPTIONAL_{ENTRY, SHIFT}
> >> https://lists.ozlabs.org/pipermail/linux-erofs/2018-July/000283.html
> >>
> >> staging: erofs: update .mount and .remount_sb
> >> https://lists.ozlabs.org/pipermail/linux-erofs/2018-July/000285.html
> > 
> > Why have these not been submitted to me for inclusion in my tree?
> Oh, let me explain, that is because the compiling error only occurs in -next
> tree, since -next collects and merges developing patches including common vfs
> stuff from multi-trees, but those patches didn't cover erofs, such as:
> 
> ('vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled")
> https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/commit/?h=for-next&id=109b45090d7d3ce2797bb1ef7f70eead5bfe0ff3
> 
> ("vfs: Require specification of size of mount data for internal mounts")
> https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/commit/?h=for-next&id=0a191e4505a4f255e6513b49426213da69bf0e80
> 
> As I checked, above vfs related patches has not been merged in staging tree, if
> I submit those erofs patches to you and after including them in
> staging-{test,nexts} tree, it can easily cause compiling error. So I just send
> them to Stephen first for fixing integrity compiling error.
> 
> Then I'd like to ask how to handle this condition to avoid potential conflict in
> between erofs and vfs changes during merging window. As Stephen suggested, we
> can disabling CONFIG_EROFS_FS temporarily to pass merge window, and after that
> we reenable CONFIG_EROFS_FS and apply those fixing patches.

Ok, doing that will work.

> I'd like to ask and make sure, do you agree that we can handle the condition by
> this way? or do you have any suggestion about solving this issue?

This is a side affect of being in the staging tree only at this point in
time.  It will get easier once things get merged correctly.

thanks,

greg k-h